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000
FXUS61 KBOX 021200
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
700 AM EST MON MAR 2 2015

.SYNOPSIS...
DRY AND BLUSTERY WEATHER FOLLOWS BEHIND THE PASSAGE OF A COLD FRONT
EARLY THIS MORNING. LOW PRESSURE FROM NORTHERN CANADA AND
ASSOCIATED LOW FORMING OVER THE PLAINS MONDAY WILL MERGE...THEN
PASS WEST AND NORTH OF NEW ENGLAND. THIS WILL BRING ABOUT A WINTRY
MIX...CHANGING TO RAIN LATE TUESDAY INTO WEDNESDAY. DRY AND COLD
WEATHER RETURNS FOR THE END OF THE WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
7 AM UPDATE...
DRY AIR ALREADY MOVING RAPIDLY IN FROM THE W DWPTS ARE ALREADY
FALLING INTO THE TEENS IN SPOTS. MOST CHANGES WERE TO MADE TO
BRING SKIES AND TEMPS UP TO CURRENT TRENDS BECAUSE THE REMAINDER
OF THE FORECAST IS ON TRACK.

PREVIOUS DISCUSSION...

THE FAST MOVING LOW PRESSURE SYSTEM THAT BROUGHT LAST NIGHT/S SNOW
HAS ALREADY EXITED THE REGION.  A COLD FRONT WAS WORKING ACROSS THE
REGION VERY EARLY THIS MORNING...BUT WITHOUT ANY PRECIPITATION.
WINDS WILL PICKUP FROM THE WEST NORTHWEST SHORTLY AFTER SUNRISE.
EXPECT IT TO BECOME WINDY BY LATE MORNING AND INTO THE AFTERNOON
WITH WEST TO NORTHWEST GUSTS BETWEEN 30 AND 40 MPH.  WE SHOULD SEE
PARTIAL SUNSHINE...BUT ALSO A LOT OF STRATO-CUMULUS CLOUDS
ESPECIALLY ACROSS THE INTERIOR.  IT WILL BE DRY TODAY...OTHER THAN
PERHAPS A PASSING FLURRY OR TWO ALONG THE EAST SLOPES OF THE
BERKSHIRES.

GIVEN THE INCREASING MARCH SUN ANGLE AND A WELL MIXED
ATMOSPHERE...EXPECT HIGHS TO RECOVER INTO THE MIDDLE AND UPPER 30S.
HOWEVER...IT WILL FEEL COLDER GIVEN THE WINDY CONDITIONS.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
TONIGHT...

A LARGE HIGH PRESSURE SYSTEM BUILDS IN FROM THE WEST.  DIURNAL
CUMULUS CLOUDS WILL DISSIPATE THIS EVENING...RESULTING IN MAINLY
CLEAR SKIES.  WINDS WILL ALSO GRADUALLY DIMINISH AND EVENTUALLY
DECOUPLE IN THE TYPICAL LOCATIONS.  THIS SHOULD ALLOW LOW TEMPS TO
FALL WELL DOWN INTO THE SINGLE DIGITS TO EVEN BELOW ZERO IN THE
NORMALLY COLDEST OUTLYING LOCATIONS.  MEANWHILE...URBAN CENTERS OF
DOWNTOWN BOSTON/PROVIDENCE WILL SEE LOW TEMPS IN THE MIDDLE TEENS.

TUESDAY...

HIGH PRESSURE WILL MOVE EAST OF THE REGION AS LOW PRESSURE TRACKS
TOWARDS THE GREAT LAKES.  PLENTY OF SUNSHINE IN THE MORNING WILL
GIVE WAY TO MOSTLY CLOUDY SKIES TUE AFTERNOON.  DRY WEATHER SHOULD
PREVAIL EVERYWHERE THROUGH MID AFTERNOON...BUT WARM ADVECTION OVER
THE COLD DOME SHOULD ALLOW LIGHT SNOW TO DEVELOP BY LATE AFTERNOON
OR EARLY EVENING ACROSS WESTERN MA/NORTHERN CT.  HIGH TEMPS AROUND
30 TO THE LOWER 30S...BUT WITH MUCH LESS WIND THEN TODAY.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
OVERVIEW AND MODEL PREFERENCES...
LONGWAVE E CANADIAN TROF REMAINS THE DOMINANT FEATURE DEFINING
THE DAILY SENSIBLE WX ACROSS THE NORTHEAST. GIVEN AO/NAO REMAIN
MOSTLY NEGATIVE AND PNA SHIFTS FROM NEGATIVE TO NEAR
NEUTRAL..SUSPECT LITTLE CHANGE WITH THIS FEATURE AT LEAST THROUGH
THE LONG TERM. THEREFORE...EXCEPT WHERE THE SRN STREAM DOMINATES
COMING OUT OF A SPLIT ROW REGIME UPSTREAM..EXPECT MAINLY BELOW
NORMAL TEMPERATURES THROUGH AT LEAST THIS COMING WEEKEND. THE ONE
CAVEAT...A PHASING OF STREAMS AS NRN AND SRN STREAM WAVES MERGE IN
THE MIDDLE OF THE WEEK IS A TRICKY FORECAST...AS THE MID LVL
WARMING IS LIKELY TO OCCUR MUCH FASTER THAN LOW LVL WARMING THANKS
TO ENTRENCHED COLD AIR AND A DEEP SNOWPACK ACROSS THE REGION ARE
LIKELY TO SLOW WARM ADVECTION NEAR THE SFC. A MIXED PRECIP EVENT
IS LIKELY...BUT NAM/GFS REMAIN COLDER WHILE ECMWF REMAINS THE MORE
AMPLIFIED /STARTING COLDER...BUT ENDING WARMER/ THAN THE REST OF
THE GUIDANCE. ECMWF HAS COOLED A BIT THOUGH...LENDING SOME
CONFIDENCE TO THE FACT THAT A BLEND OF THE ENSEMBLES /COOLER THAN
THE ECMWF BUT WITH SOME WEIGHT TOWARD A WARMER SOLUTION/ WOULD BE
THE BEST STARTING POINT FOR THIS PARTICULAR FORECAST. THIS
ENSEMBLE BLEND WORKS WELL FOR THE REMAINDER OF THE FORECAST AS
WELL.

DETAILS...

TUE NIGHT INTO WED...
OVERVIEW...
WITH A MERGER OF THE NRN STREAM /COLD AIR/ AND THE SRN STREAM
/MORE MOISTURE AND WARMER AIR/ AS WELL AS A ROBUST 50+ KT H92 LLJ
WILL LEAD TO STRONG ISENTROPIC LIFT AND OVERRUNNING AS ATTENDANT
LOW PRES PASSES N OF THE REGION. MOISTURE THROUGH THE COLUMN IS
RATHER HIGH...PWATS 2+ STD DEVIATIONS ABOVE NORMAL ARE LIKELY
GIVEN THE SRN STREAM CONNECTION. WITH COLD AIR TO START...H92
TEMPS START ABOUT -6C AND H85 TEMPS START ABOUT-8C TUE
EVENING...WARM ADVECTIVE OVERRUNNING WILL START AS SHIELD OF
MODERATE SNOWFALL..SLR/S WILL BE GRADUALLY BECOMING LOWER HOWEVER
AS WARM AIR MOVES LIFTS THE DENDRITE ZONE OUT OF PEAK OMEGA. THE
ONLY FIGHTING CHANCE THE SNOW WILL HAVE INITIALLY IS UPPER LVL
INSTABILITY WHERE H7-H4 LAPSE RATES INCREASE. THIS MAY AID THE
LIFT SOMEWHAT AND PRODUCE ENOUGH DYNAMIC COOLING TO OVERCOME THE
WARMING INITIALLY...BUT IT APPEARS THE MID LVL WARM AIR WILL WIN
EVENTUALLY. WHAT THIS ALL MEANS IS THAT MODERATE TO HEAVY PRECIP
WILL START AS SNOW...AND GRADUALLY TRANSITION TO A WINTRY MIX OF
SLEET AND FREEZING RAIN...FOLLOWED BY ALL RAIN INTO THE DAY ON WED
AS MID LVL TEMPS WARM INTO THE POSITIVE DIGITS.

TIMING...
SNOW WILL BEGIN LATE TUE IN WRN MA AND CT...THEN SPREAD E THROUGH
THE LATE AFTERNOON AND EVENING HOURS. NOT OUT OF THE QUESTION A
PERIOD OF 1+ INCH/HOUR RATES ARE OBSERVED GIVEN THE LIFT. THE SNOW
WILL BECOME HEAVIER AND WETTER AS TIME PROGRESSES THROUGH THE
OVERNIGHT. IT APPEARS...EVEN IN THE COLDER SOLUTIONS THAT A
GRADUAL TRANSITION TO SLEET THEN FREEZING RAIN OCCURS MAINLY 10PM
TO 4AM WED. HOWEVER...WITH DEEP SNOW...ANY RAIN COULD FREEZE ON
CONTACT AS SFC TEMPS ARE LIKELY TO STAY A BIT COLDER THAN 2M
TEMPS. THEREFORE...COULD SEE ICE ACCRETION EVEN AS OBSERVED TEMPS
SHIFT INTO THE MID-UPPER 30S...AND LINGER INTO MORNING HOURS WED.
HOWEVER...DRIER AND COOLER AIR WILL BE ATTEMPTING TO SHIFT IN
DURING THE DAY AS A TRANSITION TO STRAIGHT RAIN OCCURS...SUCH THAT
A LULL IN PRECIP IS POSSIBLE BY AFTERNOON. OTHERWISE...EXPECT
MAINLY RAIN DURING THE MORNING WED.

PRECIP TYPE/TOTALS...
THE INITIAL SNOWFALL IS LIKELY TO BE MAINLY MODERATE...WITH
PERIODS APPROACHING AN INCH/HOUR AND WELL END FIRST ALONG THE S
COAST AND LAST AT THE MA/NH BORDER IN THE EARLY MORNING HOURS WED.
SUSPECT THAT HIGHEST TOTALS WILL BE IN NW MA WHERE OROGRAPHIC LIFT
ENHANCES SNOWFALL RATES. ACCUMS OF ADVISORY LVL LOOK LIKELY AS
0.25-0.5 INCHES OF QPF ARE LIKELY BEFORE THE CHANGE. INITIALLY A
CHANGE TO SLEET IS EXPECTED IN HIGHER RETURNS...WITH A GRADUAL
SHIFT TO FREEZING RAIN. ICE AMOUNTS ARE TRICKY...AS 2M TEMPS ARE
LIKELY TO SKEW DATA. WITH DEEP SNOWPACK IN PLACE...WILL LIKELY SEE
SOME ICE ACCRETION APPROACHING T-0.1 INCHES IN SPOTS...ESPECIALLY
ON TOP OF THE AREA SNOWS. GRADUALLY...THE WARMING WILL LIKELY
SHIFT INTO THE 40S /ESPECIALLY AFTER DAYLIGHT WED/ AND FURTHER
ACCRETION WILL BECOME LIMITED.

OTHER IMPACTS TO CONSIDER...
THE LOWER SLR /HEAVIER-WETTER/ NATURE OF THE SNOW WILL EXACERBATE
ROOF LOADING...AND IT ONLY GET/S WORSE WITH THE POTENTIAL FOR SOME
HEAVY ICE ON TOP AND SOME LIQUID WATER GETTING INTO THE SNOWPACK.
THEREFORE...THERE IS THE RISK FOR FURTHER ROOF COLLAPSES IF NOT
TAKEN CARE OF. ALSO...AS A TRANSITION TO RAIN OCCURS...WILL LIKELY
SEE A FAIR AMOUNT OF ROADWAY PONDING AND NUISANCE POOR DRAINAGE
FLOODING ESPECIALLY DURING THE MORNING WED AS SOME SNOWMELT
OCCURS AND DRAINS CLOG. NOT EXPECT MUCH IN THE WAY OF RIVERINE OR
STREAM FLOODING AS THE SNOWPACK SHOULD EASILY HANDLE THE 1.00
INCHES OF TOTAL QPF EXPECTED. STAY TUNED FOR FURTHER DETAILS AS WE
APPROACH.

WED NIGHT INTO THU...
ANOTHER PERIOD TO WATCH. THE LEFTOVER COLD FRONTAL BOUNDARY
SHIFTS OFFSHORE LEADING TO A LULL WED AFTERNOON INTO WED EVENING.
HOWEVER...MODELS CONTINUE TO HINT AT REASONABLY ROBUST ANAFRONTAL
LOW PRES WAVE TRAVERSING THE FRONT LATE WED NIGHT INTO THU. THIS
IS SOMEWHAT ATYPICAL TO SEE ONE OF THIS STRENGTH...BUT GIVEN THE
UPPER LVL SHORTWAVE WILL BE ROTATING OVER FROM THE W AND
DEEPENING SOME...IT CAN/T BE RULED OUT. THE BIG QUESTION HERE IS
WHAT THE TEMPS WILL BE BY THIS TIME. WED COULD BE VERY WARM
ESPECIALLY IF ANY SUNNY BREAKS ARE OBSERVED AND W WINDS ARE
EXPECTED BY THE AFTERNOON. HOWEVER...BY THE OVERNIGHT
PERIOD...COLD ADVECTION WILL HAVE BEGUN ALOFT...LOWERING THE
DENDRITE ZONE. THEREFORE...YET ANOTHER ROUND OF LIGHT TO MODERATE
SNOW IS POSSIBLE...WITH ACCUMS POSSIBLY REACHING ADVISORY LVL ON
TOP OF THE SNOW AND ICE FROM THE PREVIOUS 24 HOURS. QPF VALUES OF
0.3-0.5 ARE PROGGED...WHICH WOULD SUGGEST EASY ACCUMS TO ADVISORY
LVL. IT APPEARS THE PEAK WOULD BE MAINLY ALONG THE S COAST...AT
LEAST THAT/S WHERE F-GEN AND MOISTURE SEEM TO BE MOST COINCIDENT.

THU NIGHT INTO FRI...
STRONG ARCTIC HIGH PRES MAKES A TRIUMPHANT RETURN TO THE REGION
AS 1040+HPA IN THE MASS FIELDS COMBINE WITH -20C H85 TEMPS. EXPECT
ANOTHER PERIOD OF COLD WITH POTENTIAL FOR SUB-ZERO NIGHTS AND
HIGHS WELL BELOW NORMAL. IN FACT...CAN/T RULE OUT THE POTENTIAL
NEED FOR WIND CHILL HEADLINES THU NIGHT AS THIS IS WHEN PRES
GRADIENT APPEARS STRONG ENOUGH TO SUPPORT IT.

NEXT WEEKEND...
LOOKS MAINLY DRY AS HIGH PRES REMAINS IN CONTROL COULD SEE A WEAK
UPPER DISTURBANCE AND ATTENDANT COLD FRONT ATTEMPT TO MAKE A
PASSAGE. HOWEVER...VERY DRY AIRMASS IN PLACE COULD PREEMPT ANY
PRECIPITATION ATTEMPTS.

EARLY NEXT WEEK...
HINTS AT ANOTHER POTENTIAL MODERATE LOW PRES WITH PRECIP IN
TOW...HOWEVER LOTS OF UNCERTAINTY AS TO TIMING OR P-TYPES AT THIS
TIME.

&&

.AVIATION /11Z MONDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TODAY THROUGH TUESDAY/...

TODAY...HIGH CONFIDENCE.
LAST OF THE IFR CONDITIONS ON CAPE/ISLANDS DISSIPATES BY 13-14Z.
VFR OTHERWISE. WIND GUSTS PICK UP LATER THIS MORNING WITH GUSTS
25-35 KT EXPECTED THIS AFTERNOON AND EVENING OUT OF THE W.

TONIGHT...HIGH CONFIDENCE.  WINDS GRADUALLY DIMINISH THIS EVENING
WITH VFR CONDITIONS CONTINUING.

TUESDAY...MODERATE TO HIGH CONFIDENCE.  VFR CONDITIONS
THROUGH AT LEAST MID AFTERNOON.  MVFR-IFR CONDITIONS MAY DEVELOP BY
LATE TUE AFTERNOON OR EARLY TUE EARLY EVENING ACROSS WESTERN
MA/NORTHERN CT AS LIGHT SNOW DEVELOPS.

KBOS TAF...HIGH CONFIDENCE.  NORTHWEST WIND GUSTS OF 25 TO 35 KNOTS
DEVELOP LATER THIS MORNING AND CONTINUE INTO THE AFTERNOON.

KBDL TAF...HIGH CONFIDENCE.  NORTHWEST WIND GUSTS OF 25 TO 35 KNOTS
DEVELOP LATER THIS MORNING AND CONTINUE INTO THE AFTERNOON.

OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY...

TUE NIGHT INTO WED...HIGH CONFIDENCE.
PERIODS OF IFR AND OCCASIONAL IFR POSSIBLE. SNOW TO
START...TRANSITIONING TO SLEET THEN FREEZING RAIN...THEN STRAIGHT
RAIN THROUGH THE OVERNIGHT AND EARLY MORNING HOURS. SNOW ACCUMS
GENERALLY 1-4 INCHES...ICE ACCUMS A TRACE TO A TENTH OF AN INCH
POSSIBLE. SOUTHERLY WINDS WITH LLWS LIKELY.

WED NIGHT INTO THU...MODERATE CONFIDENCE.
AFTER A LULL IN PRECIP EARLY WED...A PERIOD OF RAIN TRANSITIONING
TO SNOW IS POSSIBLE...ESPECIALLY TOWARD THE SOUTH COAST. VFR
LIKELY NORTH...IFR LIKELY IN SNOWFALL.

FRI...HIGH CONFIDENCE.
CONDITIONS IMPROVE. VFR LIKELY.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TODAY THROUGH TUESDAY/...

TODAY AND TONIGHT...HIGH CONFIDENCE.  A COLD FRONT CROSSES THE
REGION EARLY THIS MORNING AND WINDS WILL PICKUP QUICKLY AFTER
SUNRISE.  NORTHWEST WIND GUSTS OF 35 TO 40 KNOTS WILL DEVELOP BY
LATE MORNING AND CONTINUE INTO THE EVENING IN THE COLD AIR ADVECTION
PATTERN.  GALE WARNINGS POSTED FOR ALL WATERS.  WINDS WILL BEGIN TO
DIMINISH FOR THE SECOND HALF OF THE NIGHT AS HIGH PRESSURE BEGINS TO
BUILD IN FROM THE WEST.  IN ADDITION...WIDESPREAD LIGHT FREEZING
SPRAY EXPECTED TONIGHT.

TUESDAY...HIGH CONFIDENCE.  WINDS WILL HAVE DROPPED BELOW SMALL
CRAFT ADVISORY THRESHOLDS BY EARLY MORNING AS HIGH PRESSURE BUILDS
ACROSS THE WATERS. HOWEVER...LEFT OVER SWELL WILL KEEP SMALL CRAFT
SEAS GOING ACROSS THE OUTER-WATERS UNTIL AROUND NOON.

OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY..MODERATE CONFIDENCE.

TUE NIGHT INTO WED...
LOW PRES MOVES WELL INLAND...WITH A PERIOD OF SNOW RAPIDLY
CHANGING TO SLEET THEN RAIN ACROSS THE WATERS OVERNIGHT TUE NIGHT.
LOW VSBYS EXPECTED. SLY WINDS GUST TO AROUND 25 KT AT TIMES WITH
SEAS INCREASING 5-8 FT BY WED MORNING ON THE OCEAN WATERS. SMALL
CRAFT ADVISORIES LIKELY.

WED NIGHT INTO THU NIGHT...
ANOTHER WAVE OF LOW PRES MOVES ALONG A STALLED FRONTAL BOUNDARY
OVER THE WATERS. PRECIP CONTINUES. NW WINDS CONTINUE TO GUST 25
KT. ALSO...SEAS REMAIN ELEVATED 5-8FT. SMALL CRAFT ADVISORIES
LIKELY CONTINUE.

FRI...
CONDITIONS IMPROVE...SMALL CRAFT ADVISORIES MAY BE ABLE TO BE
TAKEN DOWN.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...GALE WARNING FROM 11 AM THIS MORNING TO 1 AM EST TUESDAY FOR
     ANZ231-232-250-251-254-255.
     GALE WARNING FROM 11 AM THIS MORNING TO 11 PM EST THIS EVENING
     FOR ANZ233>235-237-256.
     GALE WARNING FROM 11 AM THIS MORNING TO 8 PM EST THIS EVENING
     FOR ANZ230-236.

&&

$$
SYNOPSIS...FRANK/DOODY
NEAR TERM...FRANK/DOODY
SHORT TERM...FRANK
LONG TERM...DOODY
AVIATION...FRANK/DOODY
MARINE...FRANK/DOODY




000
FXUS61 KBOX 021200
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
700 AM EST MON MAR 2 2015

.SYNOPSIS...
DRY AND BLUSTERY WEATHER FOLLOWS BEHIND THE PASSAGE OF A COLD FRONT
EARLY THIS MORNING. LOW PRESSURE FROM NORTHERN CANADA AND
ASSOCIATED LOW FORMING OVER THE PLAINS MONDAY WILL MERGE...THEN
PASS WEST AND NORTH OF NEW ENGLAND. THIS WILL BRING ABOUT A WINTRY
MIX...CHANGING TO RAIN LATE TUESDAY INTO WEDNESDAY. DRY AND COLD
WEATHER RETURNS FOR THE END OF THE WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
7 AM UPDATE...
DRY AIR ALREADY MOVING RAPIDLY IN FROM THE W DWPTS ARE ALREADY
FALLING INTO THE TEENS IN SPOTS. MOST CHANGES WERE TO MADE TO
BRING SKIES AND TEMPS UP TO CURRENT TRENDS BECAUSE THE REMAINDER
OF THE FORECAST IS ON TRACK.

PREVIOUS DISCUSSION...

THE FAST MOVING LOW PRESSURE SYSTEM THAT BROUGHT LAST NIGHT/S SNOW
HAS ALREADY EXITED THE REGION.  A COLD FRONT WAS WORKING ACROSS THE
REGION VERY EARLY THIS MORNING...BUT WITHOUT ANY PRECIPITATION.
WINDS WILL PICKUP FROM THE WEST NORTHWEST SHORTLY AFTER SUNRISE.
EXPECT IT TO BECOME WINDY BY LATE MORNING AND INTO THE AFTERNOON
WITH WEST TO NORTHWEST GUSTS BETWEEN 30 AND 40 MPH.  WE SHOULD SEE
PARTIAL SUNSHINE...BUT ALSO A LOT OF STRATO-CUMULUS CLOUDS
ESPECIALLY ACROSS THE INTERIOR.  IT WILL BE DRY TODAY...OTHER THAN
PERHAPS A PASSING FLURRY OR TWO ALONG THE EAST SLOPES OF THE
BERKSHIRES.

GIVEN THE INCREASING MARCH SUN ANGLE AND A WELL MIXED
ATMOSPHERE...EXPECT HIGHS TO RECOVER INTO THE MIDDLE AND UPPER 30S.
HOWEVER...IT WILL FEEL COLDER GIVEN THE WINDY CONDITIONS.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
TONIGHT...

A LARGE HIGH PRESSURE SYSTEM BUILDS IN FROM THE WEST.  DIURNAL
CUMULUS CLOUDS WILL DISSIPATE THIS EVENING...RESULTING IN MAINLY
CLEAR SKIES.  WINDS WILL ALSO GRADUALLY DIMINISH AND EVENTUALLY
DECOUPLE IN THE TYPICAL LOCATIONS.  THIS SHOULD ALLOW LOW TEMPS TO
FALL WELL DOWN INTO THE SINGLE DIGITS TO EVEN BELOW ZERO IN THE
NORMALLY COLDEST OUTLYING LOCATIONS.  MEANWHILE...URBAN CENTERS OF
DOWNTOWN BOSTON/PROVIDENCE WILL SEE LOW TEMPS IN THE MIDDLE TEENS.

TUESDAY...

HIGH PRESSURE WILL MOVE EAST OF THE REGION AS LOW PRESSURE TRACKS
TOWARDS THE GREAT LAKES.  PLENTY OF SUNSHINE IN THE MORNING WILL
GIVE WAY TO MOSTLY CLOUDY SKIES TUE AFTERNOON.  DRY WEATHER SHOULD
PREVAIL EVERYWHERE THROUGH MID AFTERNOON...BUT WARM ADVECTION OVER
THE COLD DOME SHOULD ALLOW LIGHT SNOW TO DEVELOP BY LATE AFTERNOON
OR EARLY EVENING ACROSS WESTERN MA/NORTHERN CT.  HIGH TEMPS AROUND
30 TO THE LOWER 30S...BUT WITH MUCH LESS WIND THEN TODAY.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
OVERVIEW AND MODEL PREFERENCES...
LONGWAVE E CANADIAN TROF REMAINS THE DOMINANT FEATURE DEFINING
THE DAILY SENSIBLE WX ACROSS THE NORTHEAST. GIVEN AO/NAO REMAIN
MOSTLY NEGATIVE AND PNA SHIFTS FROM NEGATIVE TO NEAR
NEUTRAL..SUSPECT LITTLE CHANGE WITH THIS FEATURE AT LEAST THROUGH
THE LONG TERM. THEREFORE...EXCEPT WHERE THE SRN STREAM DOMINATES
COMING OUT OF A SPLIT ROW REGIME UPSTREAM..EXPECT MAINLY BELOW
NORMAL TEMPERATURES THROUGH AT LEAST THIS COMING WEEKEND. THE ONE
CAVEAT...A PHASING OF STREAMS AS NRN AND SRN STREAM WAVES MERGE IN
THE MIDDLE OF THE WEEK IS A TRICKY FORECAST...AS THE MID LVL
WARMING IS LIKELY TO OCCUR MUCH FASTER THAN LOW LVL WARMING THANKS
TO ENTRENCHED COLD AIR AND A DEEP SNOWPACK ACROSS THE REGION ARE
LIKELY TO SLOW WARM ADVECTION NEAR THE SFC. A MIXED PRECIP EVENT
IS LIKELY...BUT NAM/GFS REMAIN COLDER WHILE ECMWF REMAINS THE MORE
AMPLIFIED /STARTING COLDER...BUT ENDING WARMER/ THAN THE REST OF
THE GUIDANCE. ECMWF HAS COOLED A BIT THOUGH...LENDING SOME
CONFIDENCE TO THE FACT THAT A BLEND OF THE ENSEMBLES /COOLER THAN
THE ECMWF BUT WITH SOME WEIGHT TOWARD A WARMER SOLUTION/ WOULD BE
THE BEST STARTING POINT FOR THIS PARTICULAR FORECAST. THIS
ENSEMBLE BLEND WORKS WELL FOR THE REMAINDER OF THE FORECAST AS
WELL.

DETAILS...

TUE NIGHT INTO WED...
OVERVIEW...
WITH A MERGER OF THE NRN STREAM /COLD AIR/ AND THE SRN STREAM
/MORE MOISTURE AND WARMER AIR/ AS WELL AS A ROBUST 50+ KT H92 LLJ
WILL LEAD TO STRONG ISENTROPIC LIFT AND OVERRUNNING AS ATTENDANT
LOW PRES PASSES N OF THE REGION. MOISTURE THROUGH THE COLUMN IS
RATHER HIGH...PWATS 2+ STD DEVIATIONS ABOVE NORMAL ARE LIKELY
GIVEN THE SRN STREAM CONNECTION. WITH COLD AIR TO START...H92
TEMPS START ABOUT -6C AND H85 TEMPS START ABOUT-8C TUE
EVENING...WARM ADVECTIVE OVERRUNNING WILL START AS SHIELD OF
MODERATE SNOWFALL..SLR/S WILL BE GRADUALLY BECOMING LOWER HOWEVER
AS WARM AIR MOVES LIFTS THE DENDRITE ZONE OUT OF PEAK OMEGA. THE
ONLY FIGHTING CHANCE THE SNOW WILL HAVE INITIALLY IS UPPER LVL
INSTABILITY WHERE H7-H4 LAPSE RATES INCREASE. THIS MAY AID THE
LIFT SOMEWHAT AND PRODUCE ENOUGH DYNAMIC COOLING TO OVERCOME THE
WARMING INITIALLY...BUT IT APPEARS THE MID LVL WARM AIR WILL WIN
EVENTUALLY. WHAT THIS ALL MEANS IS THAT MODERATE TO HEAVY PRECIP
WILL START AS SNOW...AND GRADUALLY TRANSITION TO A WINTRY MIX OF
SLEET AND FREEZING RAIN...FOLLOWED BY ALL RAIN INTO THE DAY ON WED
AS MID LVL TEMPS WARM INTO THE POSITIVE DIGITS.

TIMING...
SNOW WILL BEGIN LATE TUE IN WRN MA AND CT...THEN SPREAD E THROUGH
THE LATE AFTERNOON AND EVENING HOURS. NOT OUT OF THE QUESTION A
PERIOD OF 1+ INCH/HOUR RATES ARE OBSERVED GIVEN THE LIFT. THE SNOW
WILL BECOME HEAVIER AND WETTER AS TIME PROGRESSES THROUGH THE
OVERNIGHT. IT APPEARS...EVEN IN THE COLDER SOLUTIONS THAT A
GRADUAL TRANSITION TO SLEET THEN FREEZING RAIN OCCURS MAINLY 10PM
TO 4AM WED. HOWEVER...WITH DEEP SNOW...ANY RAIN COULD FREEZE ON
CONTACT AS SFC TEMPS ARE LIKELY TO STAY A BIT COLDER THAN 2M
TEMPS. THEREFORE...COULD SEE ICE ACCRETION EVEN AS OBSERVED TEMPS
SHIFT INTO THE MID-UPPER 30S...AND LINGER INTO MORNING HOURS WED.
HOWEVER...DRIER AND COOLER AIR WILL BE ATTEMPTING TO SHIFT IN
DURING THE DAY AS A TRANSITION TO STRAIGHT RAIN OCCURS...SUCH THAT
A LULL IN PRECIP IS POSSIBLE BY AFTERNOON. OTHERWISE...EXPECT
MAINLY RAIN DURING THE MORNING WED.

PRECIP TYPE/TOTALS...
THE INITIAL SNOWFALL IS LIKELY TO BE MAINLY MODERATE...WITH
PERIODS APPROACHING AN INCH/HOUR AND WELL END FIRST ALONG THE S
COAST AND LAST AT THE MA/NH BORDER IN THE EARLY MORNING HOURS WED.
SUSPECT THAT HIGHEST TOTALS WILL BE IN NW MA WHERE OROGRAPHIC LIFT
ENHANCES SNOWFALL RATES. ACCUMS OF ADVISORY LVL LOOK LIKELY AS
0.25-0.5 INCHES OF QPF ARE LIKELY BEFORE THE CHANGE. INITIALLY A
CHANGE TO SLEET IS EXPECTED IN HIGHER RETURNS...WITH A GRADUAL
SHIFT TO FREEZING RAIN. ICE AMOUNTS ARE TRICKY...AS 2M TEMPS ARE
LIKELY TO SKEW DATA. WITH DEEP SNOWPACK IN PLACE...WILL LIKELY SEE
SOME ICE ACCRETION APPROACHING T-0.1 INCHES IN SPOTS...ESPECIALLY
ON TOP OF THE AREA SNOWS. GRADUALLY...THE WARMING WILL LIKELY
SHIFT INTO THE 40S /ESPECIALLY AFTER DAYLIGHT WED/ AND FURTHER
ACCRETION WILL BECOME LIMITED.

OTHER IMPACTS TO CONSIDER...
THE LOWER SLR /HEAVIER-WETTER/ NATURE OF THE SNOW WILL EXACERBATE
ROOF LOADING...AND IT ONLY GET/S WORSE WITH THE POTENTIAL FOR SOME
HEAVY ICE ON TOP AND SOME LIQUID WATER GETTING INTO THE SNOWPACK.
THEREFORE...THERE IS THE RISK FOR FURTHER ROOF COLLAPSES IF NOT
TAKEN CARE OF. ALSO...AS A TRANSITION TO RAIN OCCURS...WILL LIKELY
SEE A FAIR AMOUNT OF ROADWAY PONDING AND NUISANCE POOR DRAINAGE
FLOODING ESPECIALLY DURING THE MORNING WED AS SOME SNOWMELT
OCCURS AND DRAINS CLOG. NOT EXPECT MUCH IN THE WAY OF RIVERINE OR
STREAM FLOODING AS THE SNOWPACK SHOULD EASILY HANDLE THE 1.00
INCHES OF TOTAL QPF EXPECTED. STAY TUNED FOR FURTHER DETAILS AS WE
APPROACH.

WED NIGHT INTO THU...
ANOTHER PERIOD TO WATCH. THE LEFTOVER COLD FRONTAL BOUNDARY
SHIFTS OFFSHORE LEADING TO A LULL WED AFTERNOON INTO WED EVENING.
HOWEVER...MODELS CONTINUE TO HINT AT REASONABLY ROBUST ANAFRONTAL
LOW PRES WAVE TRAVERSING THE FRONT LATE WED NIGHT INTO THU. THIS
IS SOMEWHAT ATYPICAL TO SEE ONE OF THIS STRENGTH...BUT GIVEN THE
UPPER LVL SHORTWAVE WILL BE ROTATING OVER FROM THE W AND
DEEPENING SOME...IT CAN/T BE RULED OUT. THE BIG QUESTION HERE IS
WHAT THE TEMPS WILL BE BY THIS TIME. WED COULD BE VERY WARM
ESPECIALLY IF ANY SUNNY BREAKS ARE OBSERVED AND W WINDS ARE
EXPECTED BY THE AFTERNOON. HOWEVER...BY THE OVERNIGHT
PERIOD...COLD ADVECTION WILL HAVE BEGUN ALOFT...LOWERING THE
DENDRITE ZONE. THEREFORE...YET ANOTHER ROUND OF LIGHT TO MODERATE
SNOW IS POSSIBLE...WITH ACCUMS POSSIBLY REACHING ADVISORY LVL ON
TOP OF THE SNOW AND ICE FROM THE PREVIOUS 24 HOURS. QPF VALUES OF
0.3-0.5 ARE PROGGED...WHICH WOULD SUGGEST EASY ACCUMS TO ADVISORY
LVL. IT APPEARS THE PEAK WOULD BE MAINLY ALONG THE S COAST...AT
LEAST THAT/S WHERE F-GEN AND MOISTURE SEEM TO BE MOST COINCIDENT.

THU NIGHT INTO FRI...
STRONG ARCTIC HIGH PRES MAKES A TRIUMPHANT RETURN TO THE REGION
AS 1040+HPA IN THE MASS FIELDS COMBINE WITH -20C H85 TEMPS. EXPECT
ANOTHER PERIOD OF COLD WITH POTENTIAL FOR SUB-ZERO NIGHTS AND
HIGHS WELL BELOW NORMAL. IN FACT...CAN/T RULE OUT THE POTENTIAL
NEED FOR WIND CHILL HEADLINES THU NIGHT AS THIS IS WHEN PRES
GRADIENT APPEARS STRONG ENOUGH TO SUPPORT IT.

NEXT WEEKEND...
LOOKS MAINLY DRY AS HIGH PRES REMAINS IN CONTROL COULD SEE A WEAK
UPPER DISTURBANCE AND ATTENDANT COLD FRONT ATTEMPT TO MAKE A
PASSAGE. HOWEVER...VERY DRY AIRMASS IN PLACE COULD PREEMPT ANY
PRECIPITATION ATTEMPTS.

EARLY NEXT WEEK...
HINTS AT ANOTHER POTENTIAL MODERATE LOW PRES WITH PRECIP IN
TOW...HOWEVER LOTS OF UNCERTAINTY AS TO TIMING OR P-TYPES AT THIS
TIME.

&&

.AVIATION /11Z MONDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TODAY THROUGH TUESDAY/...

TODAY...HIGH CONFIDENCE.
LAST OF THE IFR CONDITIONS ON CAPE/ISLANDS DISSIPATES BY 13-14Z.
VFR OTHERWISE. WIND GUSTS PICK UP LATER THIS MORNING WITH GUSTS
25-35 KT EXPECTED THIS AFTERNOON AND EVENING OUT OF THE W.

TONIGHT...HIGH CONFIDENCE.  WINDS GRADUALLY DIMINISH THIS EVENING
WITH VFR CONDITIONS CONTINUING.

TUESDAY...MODERATE TO HIGH CONFIDENCE.  VFR CONDITIONS
THROUGH AT LEAST MID AFTERNOON.  MVFR-IFR CONDITIONS MAY DEVELOP BY
LATE TUE AFTERNOON OR EARLY TUE EARLY EVENING ACROSS WESTERN
MA/NORTHERN CT AS LIGHT SNOW DEVELOPS.

KBOS TAF...HIGH CONFIDENCE.  NORTHWEST WIND GUSTS OF 25 TO 35 KNOTS
DEVELOP LATER THIS MORNING AND CONTINUE INTO THE AFTERNOON.

KBDL TAF...HIGH CONFIDENCE.  NORTHWEST WIND GUSTS OF 25 TO 35 KNOTS
DEVELOP LATER THIS MORNING AND CONTINUE INTO THE AFTERNOON.

OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY...

TUE NIGHT INTO WED...HIGH CONFIDENCE.
PERIODS OF IFR AND OCCASIONAL IFR POSSIBLE. SNOW TO
START...TRANSITIONING TO SLEET THEN FREEZING RAIN...THEN STRAIGHT
RAIN THROUGH THE OVERNIGHT AND EARLY MORNING HOURS. SNOW ACCUMS
GENERALLY 1-4 INCHES...ICE ACCUMS A TRACE TO A TENTH OF AN INCH
POSSIBLE. SOUTHERLY WINDS WITH LLWS LIKELY.

WED NIGHT INTO THU...MODERATE CONFIDENCE.
AFTER A LULL IN PRECIP EARLY WED...A PERIOD OF RAIN TRANSITIONING
TO SNOW IS POSSIBLE...ESPECIALLY TOWARD THE SOUTH COAST. VFR
LIKELY NORTH...IFR LIKELY IN SNOWFALL.

FRI...HIGH CONFIDENCE.
CONDITIONS IMPROVE. VFR LIKELY.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TODAY THROUGH TUESDAY/...

TODAY AND TONIGHT...HIGH CONFIDENCE.  A COLD FRONT CROSSES THE
REGION EARLY THIS MORNING AND WINDS WILL PICKUP QUICKLY AFTER
SUNRISE.  NORTHWEST WIND GUSTS OF 35 TO 40 KNOTS WILL DEVELOP BY
LATE MORNING AND CONTINUE INTO THE EVENING IN THE COLD AIR ADVECTION
PATTERN.  GALE WARNINGS POSTED FOR ALL WATERS.  WINDS WILL BEGIN TO
DIMINISH FOR THE SECOND HALF OF THE NIGHT AS HIGH PRESSURE BEGINS TO
BUILD IN FROM THE WEST.  IN ADDITION...WIDESPREAD LIGHT FREEZING
SPRAY EXPECTED TONIGHT.

TUESDAY...HIGH CONFIDENCE.  WINDS WILL HAVE DROPPED BELOW SMALL
CRAFT ADVISORY THRESHOLDS BY EARLY MORNING AS HIGH PRESSURE BUILDS
ACROSS THE WATERS. HOWEVER...LEFT OVER SWELL WILL KEEP SMALL CRAFT
SEAS GOING ACROSS THE OUTER-WATERS UNTIL AROUND NOON.

OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY..MODERATE CONFIDENCE.

TUE NIGHT INTO WED...
LOW PRES MOVES WELL INLAND...WITH A PERIOD OF SNOW RAPIDLY
CHANGING TO SLEET THEN RAIN ACROSS THE WATERS OVERNIGHT TUE NIGHT.
LOW VSBYS EXPECTED. SLY WINDS GUST TO AROUND 25 KT AT TIMES WITH
SEAS INCREASING 5-8 FT BY WED MORNING ON THE OCEAN WATERS. SMALL
CRAFT ADVISORIES LIKELY.

WED NIGHT INTO THU NIGHT...
ANOTHER WAVE OF LOW PRES MOVES ALONG A STALLED FRONTAL BOUNDARY
OVER THE WATERS. PRECIP CONTINUES. NW WINDS CONTINUE TO GUST 25
KT. ALSO...SEAS REMAIN ELEVATED 5-8FT. SMALL CRAFT ADVISORIES
LIKELY CONTINUE.

FRI...
CONDITIONS IMPROVE...SMALL CRAFT ADVISORIES MAY BE ABLE TO BE
TAKEN DOWN.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...GALE WARNING FROM 11 AM THIS MORNING TO 1 AM EST TUESDAY FOR
     ANZ231-232-250-251-254-255.
     GALE WARNING FROM 11 AM THIS MORNING TO 11 PM EST THIS EVENING
     FOR ANZ233>235-237-256.
     GALE WARNING FROM 11 AM THIS MORNING TO 8 PM EST THIS EVENING
     FOR ANZ230-236.

&&

$$
SYNOPSIS...FRANK/DOODY
NEAR TERM...FRANK/DOODY
SHORT TERM...FRANK
LONG TERM...DOODY
AVIATION...FRANK/DOODY
MARINE...FRANK/DOODY


  [top]

000
FXUS61 KGYX 021051
AFDGYX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
551 AM EST MON MAR 2 2015

.SYNOPSIS...
BREEZY BUT RELATIVELY MILD WEATHER EXPECTED TODAY AS LOW PRESSURE
TRACKS NORTHEAST ACROSS THE MARITIME PROVINCES. HIGH PRESSURE
BUILDS IN FROM THE WEST TONIGHT AND SHIFTS OFFSHORE BY TUESDAY
AFTERNOON. LOW PRESSURE WILL SWING THROUGH SOUTHERN CANADA
TUESDAY NIGHT PUSHING A WARM FRONT NORTH ACROSS THE REGION...AND
PRODUCING A PERIOD OF SNOW AND MIXED RAIN OR SNOW ALONG THE COAST.
AS THE LOW SHIFTS TO OUR NORTH...IT WILL DRAG A COLD FRONT THROUGH
THE REGION LATE WEDNESDAY. HIGH PRESSURE WILL BUILD IN FROM THE
WEST THURSDAY AND WILL CREST OVER THE REGION ON FRIDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
550 AM...MADE SOME UPDATES TO POPS...MOSTLY TO COVER THE WEAK
AREA OF SN OVER ERN ZONES...THAT SEEMS TO BE ORIGINATING FROM SOME
LOW TO MID LVL CONVERGENCE...WEAK 850MB FRONT...AND WEAK SFC WIND
BOUNDARY. 00Z NAM-DNG SEEMS TO HAVE THE BEST HANDLE ON THIS AS IT
BUILDS A LITTLE OVER THE NEXT HOUR OR TWO AND THEN SHIFTS EWD.

OTHERWISE UPSLOPE SN LOOKS TO CONTINUE OVER THE MTNS THIS
MORNING...AS WEAK 850 MB WAVE MOVING THRU NOW...AND THEN WILL SEE
500MB FOLLOW LATER THIS MORNING.

PREVIOUSLY...FOR THE MOST PART...THE FINAL BIT OF LIGHT SNOW
ASSOCIATED WITH THE OFFSHORE SFC LOW WILL BE EXITING THE ERN ZONES
BY 09Z. 500 MB TROUGH AXIS IS HANGING BACK AND WILL CROSS THE NRN
CWA BETWEEN 15 AND 18Z. THIS WILL BRING A ROUND OF SHSN TO THE
MTNS AND WILL BE ENHANCED BY UPSLOPE LATER THIS MORNING INTO AT
LEAST THE FIRST HALF OF THE AFTERNOON. ACTUALLY...MESO MODELS ALSO
SUGGEST A FEW SHSN OR FLURRIES ACROSS THE ERN ZONES AROUND MIDDAY
WITH THIS FEATURE AS WELL....ALTHOUGH DON`T REALLY EXPECT ANY
ACCUMS HERE. HOWEVER IN THE UPSLOPE AREAS COULD SEE A FEW INCHES
IN THE LOCALLY FAVORED AREAS. DESPITE ALL THE COLD THIS
YEAR...UPSLOPE SNOW EVENT HAVE BEEN QUITE LIMITED AS MOST OF THESE
500MB SYSTEMS HAVE BEEN DEEP OR CLOSED OFF TROUGHS WHICH DRAG ALL
THE ENERGY TO OUR EAST AND PULL DRY AIR IN QUICKLY BEHIND THE MAIN
SYSTEM...LEAVING VERY LITTLE IN THE WAY OF DYNAMICS OR INSTABILITY
TO ENHANCE THE UPSLOPE.

ON THE COASTAL PLAIN...THIS TROUGH WILL KEEP THE CLOUDS
AROUND...AT LEAST FOR M/CDY CONDS THRU THE MORNING...BEFORE THE
WINDS KICK IN AND THE DOWNSLOPE BEGINS WHICH SHOULD CLEAR THINGS
OUT DURING THE AFTERNOON. SHOULD WARM UP NICELY HERE AS
WELL...WITH HIGHS IN THE MID-UPPER 30S.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
THE [PRES GRADIENT HOLDS UP THRU THE EVENING HOURS...AND THE
BREEZY CONDS WILL CONTINUE THRU THE FIRST PART OF THE EVENING
BEFORE THEY START TO DIMINISH AS THE HIGH MOVES TO OUR S. COLDER
AIR WILL MOVE IN AND SHOULD SEE SOME OF THE SHELTERED DECOUPLE
FOR THE SECOND HALF OF THE NIGHT...WITH LOWS IN SINGLE DIGITS BLO
ZERO IN THE N...AND SINGLE DIGITS TO AROUND 10 ABV ELSEWHERE.

ON TUESDAY THE HIGH WILL PASS JUST TO OUR S IN THE MORNING AND
THAN SHIFT OFF SHORE BY LATE IN THE DAY. THIS WILL KEEP FLOW
LIGHT...AND WITH MID-HIGH CLOUDS MOVING IN FROM THE NEXT SYSTEM
HIGHS WILL BE LIMITED TO THE 20S. PRECIP WILL LKLY HOLD OFF UNTIL
AFTER SUNSET...BUT A LITTLE LIGHT SN COULD BREAK OUT IN SW NH FOR
THE EVENING COMMUTE.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
IN SHORT...A CONTINUATION OF BELOW NORMAL TEMPERATURES AND NO
HEAVY PRECIPITATION EVENTS. THE MODELS ARE IN GENERAL AGREEMENT
ON THE LONG WAVE PATTERN WELL INTO NEXT WEEK. THE WESTERN RIDGE
GRADUALLY FLATTENS AND MOVES ONSHORE INTO THE WESTERN HALF OF THE
CONUS...WHILE WE SEE LINGERING TROFINESS HERE IN THE EAST AND
BELOW NORMAL TEMPERATURES...PUNCTUATED BY PERIODIC BRIEF WARM UPS.
WE BEGIN THE PERIOD WITH AN IMPULSE RACING EASTWARD FROM THE
NORTHERN PLAINS INTO NEW ENGLAND. A QUICK OVERRUNNING EVENT WITH
LIGHT MIXED PRECIPITATION TUESDAY NIGHT FOLLOWED BY A BRIEF WARM
UP ON WEDNESDAY AHEAD OF A COLD FRONT. SCATTERED UPSLOPE SNOW
SHOWERS FOLLOW FOR WEDNESDAY NIGHT AND THURSDAY. HIGH PRESSURE
BUILDS EAST ACROSS THE AREA FRIDAY. A WEAK DISTURBANCE WILL DRAG
TRAILING WARM AND COLD FRONTS ACROSS THE REGION NEXT WEEKEND.
ANOTHER COLD FRONT WILL CROSS THE AREA ERALY NEXT WEEK.

&&

.AVIATION /12Z MONDAY THROUGH FRIDAY/...
SHORT TERM...COULD STILL SEE SOME MVFR THRU ABOUT SUNRISE...AND
MAYBE LOWER IN FOG AT KCON...BUT ALL LOCATIONS SHOULD IMPROVE VFR
AFTER SUNRISE...WITH THE EXCEPTION OF KHIE...WHICH COULD LINGER AT
MVFR THOUGH TODAY...AND MAY GO LOWER BRIEFLY IS SHSN. ALL
TERMINALS SHOULD EXPECT VFR TONIGHT AND TUE.

LONG TERM...

TUE NIGHT - WED...MVFR WITH LCL IFR IN LIGHT MIXED PRECIPITATION.

THU...SCT MVFR IN MTN SNOW SHOWERS.

&&

.MARINE...
SHORT TERM...HAVE EXTENDED THE GALES THRU THE OVERNIGHT
TONIGHT...AS THE PRES GRADIENT LOOKS TO HOLD A LITTLE
LONGER...ESPECIALLY E OF CASCO BAY. BUT AS HIGH PRES BUILDS IN
WINDS WILL DIMINISH QUICKLY EARLY TUE MORNING. AS THE WINDS PICK
UP THIS AFTERNOON AND THE TEMPS DROPS THIS EVE...LOOK FOR ANOTHER
ROUND OF LIGHT FZ SPRAY TONIGHT INTO EARLY TUE.

LONG TERM...

TUE NIGHT - WED...GALE FORCE WINDS ARE POSSIBLE.

THU - FRI...SMALL CRAFT WINDS AND SEAS ARE POSSIBLE.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY FROM NOON TODAY TO 3 AM EST TUESDAY FOR
     ANZ151-153.
     GALE WARNING FROM NOON TODAY TO 3 AM EST TUESDAY FOR ANZ150-
     152-154.

&&

$$
SYNOPSIS...
NEAR TERM...CEMPA
SHORT TERM...CEMPA
LONG TERM...SCHWIBS
AVIATION...
MARINE...



000
FXUS61 KBOX 020915
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
415 AM EST MON MAR 2 2015

.SYNOPSIS...
DRY AND BLUSTERY WEATHER FOLLOWS BEHIND THE PASSAGE OF A COLD FRONT
EARLY THIS MORNING. LOW PRESSURE FROM NORTHERN CANADA AND
ASSOCIATED LOW FORMING OVER THE PLAINS MONDAY WILL MERGE...THEN
PASS WEST AND NORTH OF NEW ENGLAND. THIS WILL BRING ABOUT A WINTRY
MIX...CHANGING TO RAIN LATE TUESDAY INTO WEDNESDAY. DRY AND COLD
WEATHER RETURNS FOR THE END OF THE WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
TODAY...

THE FAST MOVING LOW PRESSURE SYSTEM THAT BROUGHT LAST NIGHT/S SNOW
HAS ALREADY EXITED THE REGION.  A COLD FRONT WAS WORKING ACROSS THE
REGION VERY EARLY THIS MORNING...BUT WITHOUT ANY PRECIPITATION.
WINDS WILL PICKUP FROM THE WEST NORTHWEST SHORTLY AFTER SUNRISE.
EXPECT IT TO BECOME WINDY BY LATE MORNING AND INTO THE AFTERNOON
WITH WEST TO NORTHWEST GUSTS BETWEEN 30 AND 40 MPH.  WE SHOULD SEE
PARTIAL SUNSHINE...BUT ALSO A LOT OF STRATO-CUMULUS CLOUDS
ESPECIALLY ACROSS THE INTERIOR.  IT WILL BE DRY TODAY...OTHER THAN
PERHAPS A PASSING FLURRY OR TWO ALONG THE EAST SLOPES OF THE
BERKSHIRES.

GIVEN THE INCREASING MARCH SUN ANGLE AND A WELL MIXED
ATMOSPHERE...EXPECT HIGHS TO RECOVER INTO THE MIDDLE AND UPPER 30S.
HOWEVER...IT WILL FEEL COLDER GIVEN THE WINDY CONDITIONS.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
TONIGHT...

A LARGE HIGH PRESSURE SYSTEM BUILDS IN FROM THE WEST.  DIURNAL
CUMULUS CLOUDS WILL DISSIPATE THIS EVENING...RESULTING IN MAINLY
CLEAR SKIES.  WINDS WILL ALSO GRADUALLY DIMINISH AND EVENTUALLY
DECOUPLE IN THE TYPICAL LOCATIONS.  THIS SHOULD ALLOW LOW TEMPS TO
FALL WELL DOWN INTO THE SINGLE DIGITS TO EVEN BELOW ZERO IN THE
NORMALLY COLDEST OUTLYING LOCATIONS.  MEANWHILE...URBAN CENTERS OF
DOWNTOWN BOSTON/PROVIDENCE WILL SEE LOW TEMPS IN THE MIDDLE TEENS.

TUESDAY...

HIGH PRESSURE WILL MOVE EAST OF THE REGION AS LOW PRESSURE TRACKS
TOWARDS THE GREAT LAKES.  PLENTY OF SUNSHINE IN THE MORNING WILL
GIVE WAY TO MOSTLY CLOUDY SKIES TUE AFTERNOON.  DRY WEATHER SHOULD
PREVAIL EVERYWHERE THROUGH MID AFTERNOON...BUT WARM ADVECTION OVER
THE COLD DOME SHOULD ALLOW LIGHT SNOW TO DEVELOP BY LATE AFTERNOON
OR EARLY EVENING ACROSS WESTERN MA/NORTHERN CT.  HIGH TEMPS AROUND
30 TO THE LOWER 30S...BUT WITH MUCH LESS WIND THEN TODAY.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
OVERVIEW AND MODEL PREFERENCES...
LONGWAVE E CANADIAN TROF REMAINS THE DOMINANT FEATURE DEFINING
THE DAILY SENSIBLE WX ACROSS THE NORTHEAST. GIVEN AO/NAO REMAIN
MOSTLY NEGATIVE AND PNA SHIFTS FROM NEGATIVE TO NEAR
NEUTRAL..SUSPECT LITTLE CHANGE WITH THIS FEATURE AT LEAST THROUGH
THE LONG TERM. THEREFORE...EXCEPT WHERE THE SRN STREAM DOMINATES
COMING OUT OF A SPLIT ROW REGIME UPSTREAM..EXPECT MAINLY BELOW
NORMAL TEMPERATURES THROUGH AT LEAST THIS COMING WEEKEND. THE ONE
CAVEAT...A PHASING OF STREAMS AS NRN AND SRN STREAM WAVES MERGE IN
THE MIDDLE OF THE WEEK IS A TRICKY FORECAST...AS THE MID LVL
WARMING IS LIKELY TO OCCUR MUCH FASTER THAN LOW LVL WARMING THANKS
TO ENTRENCHED COLD AIR AND A DEEP SNOWPACK ACROSS THE REGION ARE
LIKELY TO SLOW WARM ADVECTION NEAR THE SFC. A MIXED PRECIP EVENT
IS LIKELY...BUT NAM/GFS REMAIN COLDER WHILE ECMWF REMAINS THE MORE
AMPLIFIED /STARTING COLDER...BUT ENDING WARMER/ THAN THE REST OF
THE GUIDANCE. ECMWF HAS COOLED A BIT THOUGH...LENDING SOME
CONFIDENCE TO THE FACT THAT A BLEND OF THE ENSEMBLES /COOLER THAN
THE ECMWF BUT WITH SOME WEIGHT TOWARD A WARMER SOLUTION/ WOULD BE
THE BEST STARTING POINT FOR THIS PARTICULAR FORECAST. THIS
ENSEMBLE BLEND WORKS WELL FOR THE REMAINDER OF THE FORECAST AS
WELL.

DETAILS...

TUE NIGHT INTO WED...
OVERVIEW...
WITH A MERGER OF THE NRN STREAM /COLD AIR/ AND THE SRN STREAM
/MORE MOISTURE AND WARMER AIR/ AS WELL AS A ROBUST 50+ KT H92 LLJ
WILL LEAD TO STRONG ISENTROPIC LIFT AND OVERRUNNING AS ATTENDANT
LOW PRES PASSES N OF THE REGION. MOISTURE THROUGH THE COLUMN IS
RATHER HIGH...PWATS 2+ STD DEVIATIONS ABOVE NORMAL ARE LIKELY
GIVEN THE SRN STREAM CONNECTION. WITH COLD AIR TO START...H92
TEMPS START ABOUT -6C AND H85 TEMPS START ABOUT-8C TUE
EVENING...WARM ADVECTIVE OVERRUNNING WILL START AS SHIELD OF
MODERATE SNOWFALL..SLR/S WILL BE GRADUALLY BECOMING LOWER HOWEVER
AS WARM AIR MOVES LIFTS THE DENDRITE ZONE OUT OF PEAK OMEGA. THE
ONLY FIGHTING CHANCE THE SNOW WILL HAVE INITIALLY IS UPPER LVL
INSTABILITY WHERE H7-H4 LAPSE RATES INCREASE. THIS MAY AID THE
LIFT SOMEWHAT AND PRODUCE ENOUGH DYNAMIC COOLING TO OVERCOME THE
WARMING INITIALLY...BUT IT APPEARS THE MID LVL WARM AIR WILL WIN
EVENTUALLY. WHAT THIS ALL MEANS IS THAT MODERATE TO HEAVY PRECIP
WILL START AS SNOW...AND GRADUALLY TRANSITION TO A WINTRY MIX OF
SLEET AND FREEZING RAIN...FOLLOWED BY ALL RAIN INTO THE DAY ON WED
AS MID LVL TEMPS WARM INTO THE POSITIVE DIGITS.

TIMING...
SNOW WILL BEGIN LATE TUE IN WRN MA AND CT...THEN SPREAD E THROUGH
THE LATE AFTERNOON AND EVENING HOURS. NOT OUT OF THE QUESTION A
PERIOD OF 1+ INCH/HOUR RATES ARE OBSERVED GIVEN THE LIFT. THE SNOW
WILL BECOME HEAVIER AND WETTER AS TIME PROGRESSES THROUGH THE
OVERNIGHT. IT APPEARS...EVEN IN THE COLDER SOLUTIONS THAT A
GRADUAL TRANSITION TO SLEET THEN FREEZING RAIN OCCURS MAINLY 10PM
TO 4AM WED. HOWEVER...WITH DEEP SNOW...ANY RAIN COULD FREEZE ON
CONTACT AS SFC TEMPS ARE LIKELY TO STAY A BIT COLDER THAN 2M
TEMPS. THEREFORE...COULD SEE ICE ACCRETION EVEN AS OBSERVED TEMPS
SHIFT INTO THE MID-UPPER 30S...AND LINGER INTO MORNING HOURS WED.
HOWEVER...DRIER AND COOLER AIR WILL BE ATTEMPTING TO SHIFT IN
DURING THE DAY AS A TRANSITION TO STRAIGHT RAIN OCCURS...SUCH THAT
A LULL IN PRECIP IS POSSIBLE BY AFTERNOON. OTHERWISE...EXPECT
MAINLY RAIN DURING THE MORNING WED.

PRECIP TYPE/TOTALS...
THE INITIAL SNOWFALL IS LIKELY TO BE MAINLY MODERATE...WITH
PERIODS APPROACHING AN INCH/HOUR AND WELL END FIRST ALONG THE S
COAST AND LAST AT THE MA/NH BORDER IN THE EARLY MORNING HOURS WED.
SUSPECT THAT HIGHEST TOTALS WILL BE IN NW MA WHERE OROGRAPHIC LIFT
ENHANCES SNOWFALL RATES. ACCUMS OF ADVISORY LVL LOOK LIKELY AS
0.25-0.5 INCHES OF QPF ARE LIKELY BEFORE THE CHANGE. INITIALLY A
CHANGE TO SLEET IS EXPECTED IN HIGHER RETURNS...WITH A GRADUAL
SHIFT TO FREEZING RAIN. ICE AMOUNTS ARE TRICKY...AS 2M TEMPS ARE
LIKELY TO SKEW DATA. WITH DEEP SNOWPACK IN PLACE...WILL LIKELY SEE
SOME ICE ACCRETION APPROACHING T-0.1 INCHES IN SPOTS...ESPECIALLY
ON TOP OF THE AREA SNOWS. GRADUALLY...THE WARMING WILL LIKELY
SHIFT INTO THE 40S /ESPECIALLY AFTER DAYLIGHT WED/ AND FURTHER
ACCRETION WILL BECOME LIMITED.

OTHER IMPACTS TO CONSIDER...
THE LOWER SLR /HEAVIER-WETTER/ NATURE OF THE SNOW WILL EXACERBATE
ROOF LOADING...AND IT ONLY GET/S WORSE WITH THE POTENTIAL FOR SOME
HEAVY ICE ON TOP AND SOME LIQUID WATER GETTING INTO THE SNOWPACK.
THEREFORE...THERE IS THE RISK FOR FURTHER ROOF COLLAPSES IF NOT
TAKEN CARE OF. ALSO...AS A TRANSITION TO RAIN OCCURS...WILL LIKELY
SEE A FAIR AMOUNT OF ROADWAY PONDING AND NUISANCE POOR DRAINAGE
FLOODING ESPECIALLY DURING THE MORNING WED AS SOME SNOWMELT
OCCURS AND DRAINS CLOG. NOT EXPECT MUCH IN THE WAY OF RIVERINE OR
STREAM FLOODING AS THE SNOWPACK SHOULD EASILY HANDLE THE 1.00
INCHES OF TOTAL QPF EXPECTED. STAY TUNED FOR FURTHER DETAILS AS WE
APPROACH.

WED NIGHT INTO THU...
ANOTHER PERIOD TO WATCH. THE LEFTOVER COLD FRONTAL BOUNDARY
SHIFTS OFFSHORE LEADING TO A LULL WED AFTERNOON INTO WED EVENING.
HOWEVER...MODELS CONTINUE TO HINT AT REASONABLY ROBUST ANAFRONTAL
LOW PRES WAVE TRAVERSING THE FRONT LATE WED NIGHT INTO THU. THIS
IS SOMEWHAT ATYPICAL TO SEE ONE OF THIS STRENGTH...BUT GIVEN THE
UPPER LVL SHORTWAVE WILL BE ROTATING OVER FROM THE W AND
DEEPENING SOME...IT CAN/T BE RULED OUT. THE BIG QUESTION HERE IS
WHAT THE TEMPS WILL BE BY THIS TIME. WED COULD BE VERY WARM
ESPECIALLY IF ANY SUNNY BREAKS ARE OBSERVED AND W WINDS ARE
EXPECTED BY THE AFTERNOON. HOWEVER...BY THE OVERNIGHT
PERIOD...COLD ADVECTION WILL HAVE BEGUN ALOFT...LOWERING THE
DENDRITE ZONE. THEREFORE...YET ANOTHER ROUND OF LIGHT TO MODERATE
SNOW IS POSSIBLE...WITH ACCUMS POSSIBLY REACHING ADVISORY LVL ON
TOP OF THE SNOW AND ICE FROM THE PREVIOUS 24 HOURS. QPF VALUES OF
0.3-0.5 ARE PROGGED...WHICH WOULD SUGGEST EASY ACCUMS TO ADVISORY
LVL. IT APPEARS THE PEAK WOULD BE MAINLY ALONG THE S COAST...AT
LEAST THAT/S WHERE F-GEN AND MOISTURE SEEM TO BE MOST COINCIDENT.

THU NIGHT INTO FRI...
STRONG ARCTIC HIGH PRES MAKES A TRIUMPHANT RETURN TO THE REGION
AS 1040+HPA IN THE MASS FIELDS COMBINE WITH -20C H85 TEMPS. EXPECT
ANOTHER PERIOD OF COLD WITH POTENTIAL FOR SUB-ZERO NIGHTS AND
HIGHS WELL BELOW NORMAL. IN FACT...CAN/T RULE OUT THE POTENTIAL
NEED FOR WIND CHILL HEADLINES THU NIGHT AS THIS IS WHEN PRES
GRADIENT APPEARS STRONG ENOUGH TO SUPPORT IT.

NEXT WEEKEND...
LOOKS MAINLY DRY AS HIGH PRES REMAINS IN CONTROL COULD SEE A WEAK
UPPER DISTURBANCE AND ATTENDANT COLD FRONT ATTEMPT TO MAKE A
PASSAGE. HOWEVER...VERY DRY AIRMASS IN PLACE COULD PREEMPT ANY
PRECIPITATION ATTEMPTS.

EARLY NEXT WEEK...
HINTS AT ANOTHER POTENTIAL MODERATE LOW PRES WITH PRECIP IN
TOW...HOWEVER LOTS OF UNCERTAINTY AS TO TIMING OR P-TYPES AT THIS
TIME.

&&

.AVIATION /09Z MONDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TODAY THROUGH TUESDAY/...

TODAY...HIGH CONFIDENCE.  LINGERING IFR CONDITIONS ACROSS
CAPE/ISLANDS SHOULD IMPROVE TO VFR BY 11 OR 12Z.  OTHERWISE...EXPECT
VFR CONDITIONS TODAY DESPITE A SCATTERED TO EVEN BROKEN DECK OF
STRATO-CUMULUS CLOUDS.  WEST TO NORTHWEST WIND GUSTS OF 25 TO 35 ARE
EXPECTED TO DEVELOP LATER THIS MORNING AND CONTINUE INTO THE
AFTERNOON.

TONIGHT...HIGH CONFIDENCE.  WINDS GRADUALLY DIMINISH THIS EVENING
WITH VFR CONDITIONS CONTINUING.

TUESDAY...MODERATE TO HIGH CONFIDENCE.  VFR CONDITIONS
THROUGH AT LEAST MID AFTERNOON.  MVFR-IFR CONDITIONS MAY DEVELOP BY
LATE TUE AFTERNOON OR EARLY TUE EARLY EVENING ACROSS WESTERN
MA/NORTHERN CT AS LIGHT SNOW DEVELOPS.

KBOS TAF...HIGH CONFIDENCE.  NORTHWEST WIND GUSTS OF 25 TO 35 KNOTS
DEVELOP LATER THIS MORNING AND CONTINUE INTO THE AFTERNOON.

KBDL TAF...HIGH CONFIDENCE.  NORTHWEST WIND GUSTS OF 25 TO 35 KNOTS
DEVELOP LATER THIS MORNING AND CONTINUE INTO THE AFTERNOON.

OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY...

TUE NIGHT INTO WED...HIGH CONFIDENCE.
PERIODS OF IFR AND OCCASIONAL IFR POSSIBLE. SNOW TO
START...TRANSITIONING TO SLEET THEN FREEZING RAIN...THEN STRAIGHT
RAIN THROUGH THE OVERNIGHT AND EARLY MORNING HOURS. SNOW ACCUMS
GENERALLY 1-4 INCHES...ICE ACCUMS A TRACE TO A TENTH OF AN INCH
POSSIBLE. SOUTHERLY WINDS WITH LLWS LIKELY.

WED NIGHT INTO THU...MODERATE CONFIDENCE.
AFTER A LULL IN PRECIP EARLY WED...A PERIOD OF RAIN TRANSITIONING
TO SNOW IS POSSIBLE...ESPECIALLY TOWARD THE SOUTH COAST. VFR
LIKELY NORTH...IFR LIKELY IN SNOWFALL.

FRI...HIGH CONFIDENCE.
CONDITIONS IMPROVE. VFR LIKELY.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TODAY THROUGH TUESDAY/...

TODAY AND TONIGHT...HIGH CONFIDENCE.  A COLD FRONT CROSSES THE
REGION EARLY THIS MORNING AND WINDS WILL PICKUP QUICKLY AFTER
SUNRISE.  NORTHWEST WIND GUSTS OF 35 TO 40 KNOTS WILL DEVELOP BY
LATE MORNING AND CONTINUE INTO THE EVENING IN THE COLD AIR ADVECTION
PATTERN.  GALE WARNINGS POSTED FOR ALL WATERS.  WINDS WILL BEGIN TO
DIMINISH FOR THE SECOND HALF OF THE NIGHT AS HIGH PRESSURE BEGINS TO
BUILD IN FROM THE WEST.  IN ADDITION...WIDESPREAD LIGHT FREEZING
SPRAY EXPECTED TONIGHT.

TUESDAY...HIGH CONFIDENCE.  WINDS WILL HAVE DROPPED BELOW SMALL
CRAFT ADVISORY THRESHOLDS BY EARLY MORNING AS HIGH PRESSURE BUILDS
ACROSS THE WATERS. HOWEVER...LEFT OVER SWELL WILL KEEP SMALL CRAFT
SEAS GOING ACROSS THE OUTER-WATERS UNTIL AROUND NOON.

OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY..MODERATE CONFIDENCE.

TUE NIGHT INTO WED...
LOW PRES MOVES WELL INLAND...WITH A PERIOD OF SNOW RAPIDLY
CHANGING TO SLEET THEN RAIN ACROSS THE WATERS OVERNIGHT TUE NIGHT.
LOW VSBYS EXPECTED. SLY WINDS GUST TO AROUND 25 KT AT TIMES WITH
SEAS INCREASING 5-8 FT BY WED MORNING ON THE OCEAN WATERS. SMALL
CRAFT ADVISORIES LIKELY.

WED NIGHT INTO THU NIGHT...
ANOTHER WAVE OF LOW PRES MOVES ALONG A STALLED FRONTAL BOUNDARY
OVER THE WATERS. PRECIP CONTINUES. NW WINDS CONTINUE TO GUST 25
KT. ALSO...SEAS REMAIN ELEVATED 5-8FT. SMALL CRAFT ADVISORIES
LIKELY CONTINUE.

FRI...
CONDITIONS IMPROVE...SMALL CRAFT ADVISORIES MAY BE ABLE TO BE
TAKEN DOWN.


&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...GALE WARNING FROM 11 AM THIS MORNING TO 1 AM EST TUESDAY FOR
     ANZ231-232-250-251-254-255.
     GALE WARNING FROM 11 AM THIS MORNING TO 11 PM EST THIS EVENING
     FOR ANZ233>235-237-256.
     GALE WARNING FROM 11 AM THIS MORNING TO 8 PM EST THIS EVENING
     FOR ANZ230-236.

&&

$$
SYNOPSIS...FRANK/DOODY
NEAR TERM...FRANK
SHORT TERM...FRANK
LONG TERM...DOODY
AVIATION...FRANK/DOODY
MARINE...FRANK/DOODY




000
FXUS61 KBOX 020915
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
415 AM EST MON MAR 2 2015

.SYNOPSIS...
DRY AND BLUSTERY WEATHER FOLLOWS BEHIND THE PASSAGE OF A COLD FRONT
EARLY THIS MORNING. LOW PRESSURE FROM NORTHERN CANADA AND
ASSOCIATED LOW FORMING OVER THE PLAINS MONDAY WILL MERGE...THEN
PASS WEST AND NORTH OF NEW ENGLAND. THIS WILL BRING ABOUT A WINTRY
MIX...CHANGING TO RAIN LATE TUESDAY INTO WEDNESDAY. DRY AND COLD
WEATHER RETURNS FOR THE END OF THE WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
TODAY...

THE FAST MOVING LOW PRESSURE SYSTEM THAT BROUGHT LAST NIGHT/S SNOW
HAS ALREADY EXITED THE REGION.  A COLD FRONT WAS WORKING ACROSS THE
REGION VERY EARLY THIS MORNING...BUT WITHOUT ANY PRECIPITATION.
WINDS WILL PICKUP FROM THE WEST NORTHWEST SHORTLY AFTER SUNRISE.
EXPECT IT TO BECOME WINDY BY LATE MORNING AND INTO THE AFTERNOON
WITH WEST TO NORTHWEST GUSTS BETWEEN 30 AND 40 MPH.  WE SHOULD SEE
PARTIAL SUNSHINE...BUT ALSO A LOT OF STRATO-CUMULUS CLOUDS
ESPECIALLY ACROSS THE INTERIOR.  IT WILL BE DRY TODAY...OTHER THAN
PERHAPS A PASSING FLURRY OR TWO ALONG THE EAST SLOPES OF THE
BERKSHIRES.

GIVEN THE INCREASING MARCH SUN ANGLE AND A WELL MIXED
ATMOSPHERE...EXPECT HIGHS TO RECOVER INTO THE MIDDLE AND UPPER 30S.
HOWEVER...IT WILL FEEL COLDER GIVEN THE WINDY CONDITIONS.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
TONIGHT...

A LARGE HIGH PRESSURE SYSTEM BUILDS IN FROM THE WEST.  DIURNAL
CUMULUS CLOUDS WILL DISSIPATE THIS EVENING...RESULTING IN MAINLY
CLEAR SKIES.  WINDS WILL ALSO GRADUALLY DIMINISH AND EVENTUALLY
DECOUPLE IN THE TYPICAL LOCATIONS.  THIS SHOULD ALLOW LOW TEMPS TO
FALL WELL DOWN INTO THE SINGLE DIGITS TO EVEN BELOW ZERO IN THE
NORMALLY COLDEST OUTLYING LOCATIONS.  MEANWHILE...URBAN CENTERS OF
DOWNTOWN BOSTON/PROVIDENCE WILL SEE LOW TEMPS IN THE MIDDLE TEENS.

TUESDAY...

HIGH PRESSURE WILL MOVE EAST OF THE REGION AS LOW PRESSURE TRACKS
TOWARDS THE GREAT LAKES.  PLENTY OF SUNSHINE IN THE MORNING WILL
GIVE WAY TO MOSTLY CLOUDY SKIES TUE AFTERNOON.  DRY WEATHER SHOULD
PREVAIL EVERYWHERE THROUGH MID AFTERNOON...BUT WARM ADVECTION OVER
THE COLD DOME SHOULD ALLOW LIGHT SNOW TO DEVELOP BY LATE AFTERNOON
OR EARLY EVENING ACROSS WESTERN MA/NORTHERN CT.  HIGH TEMPS AROUND
30 TO THE LOWER 30S...BUT WITH MUCH LESS WIND THEN TODAY.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
OVERVIEW AND MODEL PREFERENCES...
LONGWAVE E CANADIAN TROF REMAINS THE DOMINANT FEATURE DEFINING
THE DAILY SENSIBLE WX ACROSS THE NORTHEAST. GIVEN AO/NAO REMAIN
MOSTLY NEGATIVE AND PNA SHIFTS FROM NEGATIVE TO NEAR
NEUTRAL..SUSPECT LITTLE CHANGE WITH THIS FEATURE AT LEAST THROUGH
THE LONG TERM. THEREFORE...EXCEPT WHERE THE SRN STREAM DOMINATES
COMING OUT OF A SPLIT ROW REGIME UPSTREAM..EXPECT MAINLY BELOW
NORMAL TEMPERATURES THROUGH AT LEAST THIS COMING WEEKEND. THE ONE
CAVEAT...A PHASING OF STREAMS AS NRN AND SRN STREAM WAVES MERGE IN
THE MIDDLE OF THE WEEK IS A TRICKY FORECAST...AS THE MID LVL
WARMING IS LIKELY TO OCCUR MUCH FASTER THAN LOW LVL WARMING THANKS
TO ENTRENCHED COLD AIR AND A DEEP SNOWPACK ACROSS THE REGION ARE
LIKELY TO SLOW WARM ADVECTION NEAR THE SFC. A MIXED PRECIP EVENT
IS LIKELY...BUT NAM/GFS REMAIN COLDER WHILE ECMWF REMAINS THE MORE
AMPLIFIED /STARTING COLDER...BUT ENDING WARMER/ THAN THE REST OF
THE GUIDANCE. ECMWF HAS COOLED A BIT THOUGH...LENDING SOME
CONFIDENCE TO THE FACT THAT A BLEND OF THE ENSEMBLES /COOLER THAN
THE ECMWF BUT WITH SOME WEIGHT TOWARD A WARMER SOLUTION/ WOULD BE
THE BEST STARTING POINT FOR THIS PARTICULAR FORECAST. THIS
ENSEMBLE BLEND WORKS WELL FOR THE REMAINDER OF THE FORECAST AS
WELL.

DETAILS...

TUE NIGHT INTO WED...
OVERVIEW...
WITH A MERGER OF THE NRN STREAM /COLD AIR/ AND THE SRN STREAM
/MORE MOISTURE AND WARMER AIR/ AS WELL AS A ROBUST 50+ KT H92 LLJ
WILL LEAD TO STRONG ISENTROPIC LIFT AND OVERRUNNING AS ATTENDANT
LOW PRES PASSES N OF THE REGION. MOISTURE THROUGH THE COLUMN IS
RATHER HIGH...PWATS 2+ STD DEVIATIONS ABOVE NORMAL ARE LIKELY
GIVEN THE SRN STREAM CONNECTION. WITH COLD AIR TO START...H92
TEMPS START ABOUT -6C AND H85 TEMPS START ABOUT-8C TUE
EVENING...WARM ADVECTIVE OVERRUNNING WILL START AS SHIELD OF
MODERATE SNOWFALL..SLR/S WILL BE GRADUALLY BECOMING LOWER HOWEVER
AS WARM AIR MOVES LIFTS THE DENDRITE ZONE OUT OF PEAK OMEGA. THE
ONLY FIGHTING CHANCE THE SNOW WILL HAVE INITIALLY IS UPPER LVL
INSTABILITY WHERE H7-H4 LAPSE RATES INCREASE. THIS MAY AID THE
LIFT SOMEWHAT AND PRODUCE ENOUGH DYNAMIC COOLING TO OVERCOME THE
WARMING INITIALLY...BUT IT APPEARS THE MID LVL WARM AIR WILL WIN
EVENTUALLY. WHAT THIS ALL MEANS IS THAT MODERATE TO HEAVY PRECIP
WILL START AS SNOW...AND GRADUALLY TRANSITION TO A WINTRY MIX OF
SLEET AND FREEZING RAIN...FOLLOWED BY ALL RAIN INTO THE DAY ON WED
AS MID LVL TEMPS WARM INTO THE POSITIVE DIGITS.

TIMING...
SNOW WILL BEGIN LATE TUE IN WRN MA AND CT...THEN SPREAD E THROUGH
THE LATE AFTERNOON AND EVENING HOURS. NOT OUT OF THE QUESTION A
PERIOD OF 1+ INCH/HOUR RATES ARE OBSERVED GIVEN THE LIFT. THE SNOW
WILL BECOME HEAVIER AND WETTER AS TIME PROGRESSES THROUGH THE
OVERNIGHT. IT APPEARS...EVEN IN THE COLDER SOLUTIONS THAT A
GRADUAL TRANSITION TO SLEET THEN FREEZING RAIN OCCURS MAINLY 10PM
TO 4AM WED. HOWEVER...WITH DEEP SNOW...ANY RAIN COULD FREEZE ON
CONTACT AS SFC TEMPS ARE LIKELY TO STAY A BIT COLDER THAN 2M
TEMPS. THEREFORE...COULD SEE ICE ACCRETION EVEN AS OBSERVED TEMPS
SHIFT INTO THE MID-UPPER 30S...AND LINGER INTO MORNING HOURS WED.
HOWEVER...DRIER AND COOLER AIR WILL BE ATTEMPTING TO SHIFT IN
DURING THE DAY AS A TRANSITION TO STRAIGHT RAIN OCCURS...SUCH THAT
A LULL IN PRECIP IS POSSIBLE BY AFTERNOON. OTHERWISE...EXPECT
MAINLY RAIN DURING THE MORNING WED.

PRECIP TYPE/TOTALS...
THE INITIAL SNOWFALL IS LIKELY TO BE MAINLY MODERATE...WITH
PERIODS APPROACHING AN INCH/HOUR AND WELL END FIRST ALONG THE S
COAST AND LAST AT THE MA/NH BORDER IN THE EARLY MORNING HOURS WED.
SUSPECT THAT HIGHEST TOTALS WILL BE IN NW MA WHERE OROGRAPHIC LIFT
ENHANCES SNOWFALL RATES. ACCUMS OF ADVISORY LVL LOOK LIKELY AS
0.25-0.5 INCHES OF QPF ARE LIKELY BEFORE THE CHANGE. INITIALLY A
CHANGE TO SLEET IS EXPECTED IN HIGHER RETURNS...WITH A GRADUAL
SHIFT TO FREEZING RAIN. ICE AMOUNTS ARE TRICKY...AS 2M TEMPS ARE
LIKELY TO SKEW DATA. WITH DEEP SNOWPACK IN PLACE...WILL LIKELY SEE
SOME ICE ACCRETION APPROACHING T-0.1 INCHES IN SPOTS...ESPECIALLY
ON TOP OF THE AREA SNOWS. GRADUALLY...THE WARMING WILL LIKELY
SHIFT INTO THE 40S /ESPECIALLY AFTER DAYLIGHT WED/ AND FURTHER
ACCRETION WILL BECOME LIMITED.

OTHER IMPACTS TO CONSIDER...
THE LOWER SLR /HEAVIER-WETTER/ NATURE OF THE SNOW WILL EXACERBATE
ROOF LOADING...AND IT ONLY GET/S WORSE WITH THE POTENTIAL FOR SOME
HEAVY ICE ON TOP AND SOME LIQUID WATER GETTING INTO THE SNOWPACK.
THEREFORE...THERE IS THE RISK FOR FURTHER ROOF COLLAPSES IF NOT
TAKEN CARE OF. ALSO...AS A TRANSITION TO RAIN OCCURS...WILL LIKELY
SEE A FAIR AMOUNT OF ROADWAY PONDING AND NUISANCE POOR DRAINAGE
FLOODING ESPECIALLY DURING THE MORNING WED AS SOME SNOWMELT
OCCURS AND DRAINS CLOG. NOT EXPECT MUCH IN THE WAY OF RIVERINE OR
STREAM FLOODING AS THE SNOWPACK SHOULD EASILY HANDLE THE 1.00
INCHES OF TOTAL QPF EXPECTED. STAY TUNED FOR FURTHER DETAILS AS WE
APPROACH.

WED NIGHT INTO THU...
ANOTHER PERIOD TO WATCH. THE LEFTOVER COLD FRONTAL BOUNDARY
SHIFTS OFFSHORE LEADING TO A LULL WED AFTERNOON INTO WED EVENING.
HOWEVER...MODELS CONTINUE TO HINT AT REASONABLY ROBUST ANAFRONTAL
LOW PRES WAVE TRAVERSING THE FRONT LATE WED NIGHT INTO THU. THIS
IS SOMEWHAT ATYPICAL TO SEE ONE OF THIS STRENGTH...BUT GIVEN THE
UPPER LVL SHORTWAVE WILL BE ROTATING OVER FROM THE W AND
DEEPENING SOME...IT CAN/T BE RULED OUT. THE BIG QUESTION HERE IS
WHAT THE TEMPS WILL BE BY THIS TIME. WED COULD BE VERY WARM
ESPECIALLY IF ANY SUNNY BREAKS ARE OBSERVED AND W WINDS ARE
EXPECTED BY THE AFTERNOON. HOWEVER...BY THE OVERNIGHT
PERIOD...COLD ADVECTION WILL HAVE BEGUN ALOFT...LOWERING THE
DENDRITE ZONE. THEREFORE...YET ANOTHER ROUND OF LIGHT TO MODERATE
SNOW IS POSSIBLE...WITH ACCUMS POSSIBLY REACHING ADVISORY LVL ON
TOP OF THE SNOW AND ICE FROM THE PREVIOUS 24 HOURS. QPF VALUES OF
0.3-0.5 ARE PROGGED...WHICH WOULD SUGGEST EASY ACCUMS TO ADVISORY
LVL. IT APPEARS THE PEAK WOULD BE MAINLY ALONG THE S COAST...AT
LEAST THAT/S WHERE F-GEN AND MOISTURE SEEM TO BE MOST COINCIDENT.

THU NIGHT INTO FRI...
STRONG ARCTIC HIGH PRES MAKES A TRIUMPHANT RETURN TO THE REGION
AS 1040+HPA IN THE MASS FIELDS COMBINE WITH -20C H85 TEMPS. EXPECT
ANOTHER PERIOD OF COLD WITH POTENTIAL FOR SUB-ZERO NIGHTS AND
HIGHS WELL BELOW NORMAL. IN FACT...CAN/T RULE OUT THE POTENTIAL
NEED FOR WIND CHILL HEADLINES THU NIGHT AS THIS IS WHEN PRES
GRADIENT APPEARS STRONG ENOUGH TO SUPPORT IT.

NEXT WEEKEND...
LOOKS MAINLY DRY AS HIGH PRES REMAINS IN CONTROL COULD SEE A WEAK
UPPER DISTURBANCE AND ATTENDANT COLD FRONT ATTEMPT TO MAKE A
PASSAGE. HOWEVER...VERY DRY AIRMASS IN PLACE COULD PREEMPT ANY
PRECIPITATION ATTEMPTS.

EARLY NEXT WEEK...
HINTS AT ANOTHER POTENTIAL MODERATE LOW PRES WITH PRECIP IN
TOW...HOWEVER LOTS OF UNCERTAINTY AS TO TIMING OR P-TYPES AT THIS
TIME.

&&

.AVIATION /09Z MONDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TODAY THROUGH TUESDAY/...

TODAY...HIGH CONFIDENCE.  LINGERING IFR CONDITIONS ACROSS
CAPE/ISLANDS SHOULD IMPROVE TO VFR BY 11 OR 12Z.  OTHERWISE...EXPECT
VFR CONDITIONS TODAY DESPITE A SCATTERED TO EVEN BROKEN DECK OF
STRATO-CUMULUS CLOUDS.  WEST TO NORTHWEST WIND GUSTS OF 25 TO 35 ARE
EXPECTED TO DEVELOP LATER THIS MORNING AND CONTINUE INTO THE
AFTERNOON.

TONIGHT...HIGH CONFIDENCE.  WINDS GRADUALLY DIMINISH THIS EVENING
WITH VFR CONDITIONS CONTINUING.

TUESDAY...MODERATE TO HIGH CONFIDENCE.  VFR CONDITIONS
THROUGH AT LEAST MID AFTERNOON.  MVFR-IFR CONDITIONS MAY DEVELOP BY
LATE TUE AFTERNOON OR EARLY TUE EARLY EVENING ACROSS WESTERN
MA/NORTHERN CT AS LIGHT SNOW DEVELOPS.

KBOS TAF...HIGH CONFIDENCE.  NORTHWEST WIND GUSTS OF 25 TO 35 KNOTS
DEVELOP LATER THIS MORNING AND CONTINUE INTO THE AFTERNOON.

KBDL TAF...HIGH CONFIDENCE.  NORTHWEST WIND GUSTS OF 25 TO 35 KNOTS
DEVELOP LATER THIS MORNING AND CONTINUE INTO THE AFTERNOON.

OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY...

TUE NIGHT INTO WED...HIGH CONFIDENCE.
PERIODS OF IFR AND OCCASIONAL IFR POSSIBLE. SNOW TO
START...TRANSITIONING TO SLEET THEN FREEZING RAIN...THEN STRAIGHT
RAIN THROUGH THE OVERNIGHT AND EARLY MORNING HOURS. SNOW ACCUMS
GENERALLY 1-4 INCHES...ICE ACCUMS A TRACE TO A TENTH OF AN INCH
POSSIBLE. SOUTHERLY WINDS WITH LLWS LIKELY.

WED NIGHT INTO THU...MODERATE CONFIDENCE.
AFTER A LULL IN PRECIP EARLY WED...A PERIOD OF RAIN TRANSITIONING
TO SNOW IS POSSIBLE...ESPECIALLY TOWARD THE SOUTH COAST. VFR
LIKELY NORTH...IFR LIKELY IN SNOWFALL.

FRI...HIGH CONFIDENCE.
CONDITIONS IMPROVE. VFR LIKELY.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TODAY THROUGH TUESDAY/...

TODAY AND TONIGHT...HIGH CONFIDENCE.  A COLD FRONT CROSSES THE
REGION EARLY THIS MORNING AND WINDS WILL PICKUP QUICKLY AFTER
SUNRISE.  NORTHWEST WIND GUSTS OF 35 TO 40 KNOTS WILL DEVELOP BY
LATE MORNING AND CONTINUE INTO THE EVENING IN THE COLD AIR ADVECTION
PATTERN.  GALE WARNINGS POSTED FOR ALL WATERS.  WINDS WILL BEGIN TO
DIMINISH FOR THE SECOND HALF OF THE NIGHT AS HIGH PRESSURE BEGINS TO
BUILD IN FROM THE WEST.  IN ADDITION...WIDESPREAD LIGHT FREEZING
SPRAY EXPECTED TONIGHT.

TUESDAY...HIGH CONFIDENCE.  WINDS WILL HAVE DROPPED BELOW SMALL
CRAFT ADVISORY THRESHOLDS BY EARLY MORNING AS HIGH PRESSURE BUILDS
ACROSS THE WATERS. HOWEVER...LEFT OVER SWELL WILL KEEP SMALL CRAFT
SEAS GOING ACROSS THE OUTER-WATERS UNTIL AROUND NOON.

OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY..MODERATE CONFIDENCE.

TUE NIGHT INTO WED...
LOW PRES MOVES WELL INLAND...WITH A PERIOD OF SNOW RAPIDLY
CHANGING TO SLEET THEN RAIN ACROSS THE WATERS OVERNIGHT TUE NIGHT.
LOW VSBYS EXPECTED. SLY WINDS GUST TO AROUND 25 KT AT TIMES WITH
SEAS INCREASING 5-8 FT BY WED MORNING ON THE OCEAN WATERS. SMALL
CRAFT ADVISORIES LIKELY.

WED NIGHT INTO THU NIGHT...
ANOTHER WAVE OF LOW PRES MOVES ALONG A STALLED FRONTAL BOUNDARY
OVER THE WATERS. PRECIP CONTINUES. NW WINDS CONTINUE TO GUST 25
KT. ALSO...SEAS REMAIN ELEVATED 5-8FT. SMALL CRAFT ADVISORIES
LIKELY CONTINUE.

FRI...
CONDITIONS IMPROVE...SMALL CRAFT ADVISORIES MAY BE ABLE TO BE
TAKEN DOWN.


&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...GALE WARNING FROM 11 AM THIS MORNING TO 1 AM EST TUESDAY FOR
     ANZ231-232-250-251-254-255.
     GALE WARNING FROM 11 AM THIS MORNING TO 11 PM EST THIS EVENING
     FOR ANZ233>235-237-256.
     GALE WARNING FROM 11 AM THIS MORNING TO 8 PM EST THIS EVENING
     FOR ANZ230-236.

&&

$$
SYNOPSIS...FRANK/DOODY
NEAR TERM...FRANK
SHORT TERM...FRANK
LONG TERM...DOODY
AVIATION...FRANK/DOODY
MARINE...FRANK/DOODY




000
FXUS61 KBOX 020915
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
415 AM EST MON MAR 2 2015

.SYNOPSIS...
DRY AND BLUSTERY WEATHER FOLLOWS BEHIND THE PASSAGE OF A COLD FRONT
EARLY THIS MORNING. LOW PRESSURE FROM NORTHERN CANADA AND
ASSOCIATED LOW FORMING OVER THE PLAINS MONDAY WILL MERGE...THEN
PASS WEST AND NORTH OF NEW ENGLAND. THIS WILL BRING ABOUT A WINTRY
MIX...CHANGING TO RAIN LATE TUESDAY INTO WEDNESDAY. DRY AND COLD
WEATHER RETURNS FOR THE END OF THE WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
TODAY...

THE FAST MOVING LOW PRESSURE SYSTEM THAT BROUGHT LAST NIGHT/S SNOW
HAS ALREADY EXITED THE REGION.  A COLD FRONT WAS WORKING ACROSS THE
REGION VERY EARLY THIS MORNING...BUT WITHOUT ANY PRECIPITATION.
WINDS WILL PICKUP FROM THE WEST NORTHWEST SHORTLY AFTER SUNRISE.
EXPECT IT TO BECOME WINDY BY LATE MORNING AND INTO THE AFTERNOON
WITH WEST TO NORTHWEST GUSTS BETWEEN 30 AND 40 MPH.  WE SHOULD SEE
PARTIAL SUNSHINE...BUT ALSO A LOT OF STRATO-CUMULUS CLOUDS
ESPECIALLY ACROSS THE INTERIOR.  IT WILL BE DRY TODAY...OTHER THAN
PERHAPS A PASSING FLURRY OR TWO ALONG THE EAST SLOPES OF THE
BERKSHIRES.

GIVEN THE INCREASING MARCH SUN ANGLE AND A WELL MIXED
ATMOSPHERE...EXPECT HIGHS TO RECOVER INTO THE MIDDLE AND UPPER 30S.
HOWEVER...IT WILL FEEL COLDER GIVEN THE WINDY CONDITIONS.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
TONIGHT...

A LARGE HIGH PRESSURE SYSTEM BUILDS IN FROM THE WEST.  DIURNAL
CUMULUS CLOUDS WILL DISSIPATE THIS EVENING...RESULTING IN MAINLY
CLEAR SKIES.  WINDS WILL ALSO GRADUALLY DIMINISH AND EVENTUALLY
DECOUPLE IN THE TYPICAL LOCATIONS.  THIS SHOULD ALLOW LOW TEMPS TO
FALL WELL DOWN INTO THE SINGLE DIGITS TO EVEN BELOW ZERO IN THE
NORMALLY COLDEST OUTLYING LOCATIONS.  MEANWHILE...URBAN CENTERS OF
DOWNTOWN BOSTON/PROVIDENCE WILL SEE LOW TEMPS IN THE MIDDLE TEENS.

TUESDAY...

HIGH PRESSURE WILL MOVE EAST OF THE REGION AS LOW PRESSURE TRACKS
TOWARDS THE GREAT LAKES.  PLENTY OF SUNSHINE IN THE MORNING WILL
GIVE WAY TO MOSTLY CLOUDY SKIES TUE AFTERNOON.  DRY WEATHER SHOULD
PREVAIL EVERYWHERE THROUGH MID AFTERNOON...BUT WARM ADVECTION OVER
THE COLD DOME SHOULD ALLOW LIGHT SNOW TO DEVELOP BY LATE AFTERNOON
OR EARLY EVENING ACROSS WESTERN MA/NORTHERN CT.  HIGH TEMPS AROUND
30 TO THE LOWER 30S...BUT WITH MUCH LESS WIND THEN TODAY.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
OVERVIEW AND MODEL PREFERENCES...
LONGWAVE E CANADIAN TROF REMAINS THE DOMINANT FEATURE DEFINING
THE DAILY SENSIBLE WX ACROSS THE NORTHEAST. GIVEN AO/NAO REMAIN
MOSTLY NEGATIVE AND PNA SHIFTS FROM NEGATIVE TO NEAR
NEUTRAL..SUSPECT LITTLE CHANGE WITH THIS FEATURE AT LEAST THROUGH
THE LONG TERM. THEREFORE...EXCEPT WHERE THE SRN STREAM DOMINATES
COMING OUT OF A SPLIT ROW REGIME UPSTREAM..EXPECT MAINLY BELOW
NORMAL TEMPERATURES THROUGH AT LEAST THIS COMING WEEKEND. THE ONE
CAVEAT...A PHASING OF STREAMS AS NRN AND SRN STREAM WAVES MERGE IN
THE MIDDLE OF THE WEEK IS A TRICKY FORECAST...AS THE MID LVL
WARMING IS LIKELY TO OCCUR MUCH FASTER THAN LOW LVL WARMING THANKS
TO ENTRENCHED COLD AIR AND A DEEP SNOWPACK ACROSS THE REGION ARE
LIKELY TO SLOW WARM ADVECTION NEAR THE SFC. A MIXED PRECIP EVENT
IS LIKELY...BUT NAM/GFS REMAIN COLDER WHILE ECMWF REMAINS THE MORE
AMPLIFIED /STARTING COLDER...BUT ENDING WARMER/ THAN THE REST OF
THE GUIDANCE. ECMWF HAS COOLED A BIT THOUGH...LENDING SOME
CONFIDENCE TO THE FACT THAT A BLEND OF THE ENSEMBLES /COOLER THAN
THE ECMWF BUT WITH SOME WEIGHT TOWARD A WARMER SOLUTION/ WOULD BE
THE BEST STARTING POINT FOR THIS PARTICULAR FORECAST. THIS
ENSEMBLE BLEND WORKS WELL FOR THE REMAINDER OF THE FORECAST AS
WELL.

DETAILS...

TUE NIGHT INTO WED...
OVERVIEW...
WITH A MERGER OF THE NRN STREAM /COLD AIR/ AND THE SRN STREAM
/MORE MOISTURE AND WARMER AIR/ AS WELL AS A ROBUST 50+ KT H92 LLJ
WILL LEAD TO STRONG ISENTROPIC LIFT AND OVERRUNNING AS ATTENDANT
LOW PRES PASSES N OF THE REGION. MOISTURE THROUGH THE COLUMN IS
RATHER HIGH...PWATS 2+ STD DEVIATIONS ABOVE NORMAL ARE LIKELY
GIVEN THE SRN STREAM CONNECTION. WITH COLD AIR TO START...H92
TEMPS START ABOUT -6C AND H85 TEMPS START ABOUT-8C TUE
EVENING...WARM ADVECTIVE OVERRUNNING WILL START AS SHIELD OF
MODERATE SNOWFALL..SLR/S WILL BE GRADUALLY BECOMING LOWER HOWEVER
AS WARM AIR MOVES LIFTS THE DENDRITE ZONE OUT OF PEAK OMEGA. THE
ONLY FIGHTING CHANCE THE SNOW WILL HAVE INITIALLY IS UPPER LVL
INSTABILITY WHERE H7-H4 LAPSE RATES INCREASE. THIS MAY AID THE
LIFT SOMEWHAT AND PRODUCE ENOUGH DYNAMIC COOLING TO OVERCOME THE
WARMING INITIALLY...BUT IT APPEARS THE MID LVL WARM AIR WILL WIN
EVENTUALLY. WHAT THIS ALL MEANS IS THAT MODERATE TO HEAVY PRECIP
WILL START AS SNOW...AND GRADUALLY TRANSITION TO A WINTRY MIX OF
SLEET AND FREEZING RAIN...FOLLOWED BY ALL RAIN INTO THE DAY ON WED
AS MID LVL TEMPS WARM INTO THE POSITIVE DIGITS.

TIMING...
SNOW WILL BEGIN LATE TUE IN WRN MA AND CT...THEN SPREAD E THROUGH
THE LATE AFTERNOON AND EVENING HOURS. NOT OUT OF THE QUESTION A
PERIOD OF 1+ INCH/HOUR RATES ARE OBSERVED GIVEN THE LIFT. THE SNOW
WILL BECOME HEAVIER AND WETTER AS TIME PROGRESSES THROUGH THE
OVERNIGHT. IT APPEARS...EVEN IN THE COLDER SOLUTIONS THAT A
GRADUAL TRANSITION TO SLEET THEN FREEZING RAIN OCCURS MAINLY 10PM
TO 4AM WED. HOWEVER...WITH DEEP SNOW...ANY RAIN COULD FREEZE ON
CONTACT AS SFC TEMPS ARE LIKELY TO STAY A BIT COLDER THAN 2M
TEMPS. THEREFORE...COULD SEE ICE ACCRETION EVEN AS OBSERVED TEMPS
SHIFT INTO THE MID-UPPER 30S...AND LINGER INTO MORNING HOURS WED.
HOWEVER...DRIER AND COOLER AIR WILL BE ATTEMPTING TO SHIFT IN
DURING THE DAY AS A TRANSITION TO STRAIGHT RAIN OCCURS...SUCH THAT
A LULL IN PRECIP IS POSSIBLE BY AFTERNOON. OTHERWISE...EXPECT
MAINLY RAIN DURING THE MORNING WED.

PRECIP TYPE/TOTALS...
THE INITIAL SNOWFALL IS LIKELY TO BE MAINLY MODERATE...WITH
PERIODS APPROACHING AN INCH/HOUR AND WELL END FIRST ALONG THE S
COAST AND LAST AT THE MA/NH BORDER IN THE EARLY MORNING HOURS WED.
SUSPECT THAT HIGHEST TOTALS WILL BE IN NW MA WHERE OROGRAPHIC LIFT
ENHANCES SNOWFALL RATES. ACCUMS OF ADVISORY LVL LOOK LIKELY AS
0.25-0.5 INCHES OF QPF ARE LIKELY BEFORE THE CHANGE. INITIALLY A
CHANGE TO SLEET IS EXPECTED IN HIGHER RETURNS...WITH A GRADUAL
SHIFT TO FREEZING RAIN. ICE AMOUNTS ARE TRICKY...AS 2M TEMPS ARE
LIKELY TO SKEW DATA. WITH DEEP SNOWPACK IN PLACE...WILL LIKELY SEE
SOME ICE ACCRETION APPROACHING T-0.1 INCHES IN SPOTS...ESPECIALLY
ON TOP OF THE AREA SNOWS. GRADUALLY...THE WARMING WILL LIKELY
SHIFT INTO THE 40S /ESPECIALLY AFTER DAYLIGHT WED/ AND FURTHER
ACCRETION WILL BECOME LIMITED.

OTHER IMPACTS TO CONSIDER...
THE LOWER SLR /HEAVIER-WETTER/ NATURE OF THE SNOW WILL EXACERBATE
ROOF LOADING...AND IT ONLY GET/S WORSE WITH THE POTENTIAL FOR SOME
HEAVY ICE ON TOP AND SOME LIQUID WATER GETTING INTO THE SNOWPACK.
THEREFORE...THERE IS THE RISK FOR FURTHER ROOF COLLAPSES IF NOT
TAKEN CARE OF. ALSO...AS A TRANSITION TO RAIN OCCURS...WILL LIKELY
SEE A FAIR AMOUNT OF ROADWAY PONDING AND NUISANCE POOR DRAINAGE
FLOODING ESPECIALLY DURING THE MORNING WED AS SOME SNOWMELT
OCCURS AND DRAINS CLOG. NOT EXPECT MUCH IN THE WAY OF RIVERINE OR
STREAM FLOODING AS THE SNOWPACK SHOULD EASILY HANDLE THE 1.00
INCHES OF TOTAL QPF EXPECTED. STAY TUNED FOR FURTHER DETAILS AS WE
APPROACH.

WED NIGHT INTO THU...
ANOTHER PERIOD TO WATCH. THE LEFTOVER COLD FRONTAL BOUNDARY
SHIFTS OFFSHORE LEADING TO A LULL WED AFTERNOON INTO WED EVENING.
HOWEVER...MODELS CONTINUE TO HINT AT REASONABLY ROBUST ANAFRONTAL
LOW PRES WAVE TRAVERSING THE FRONT LATE WED NIGHT INTO THU. THIS
IS SOMEWHAT ATYPICAL TO SEE ONE OF THIS STRENGTH...BUT GIVEN THE
UPPER LVL SHORTWAVE WILL BE ROTATING OVER FROM THE W AND
DEEPENING SOME...IT CAN/T BE RULED OUT. THE BIG QUESTION HERE IS
WHAT THE TEMPS WILL BE BY THIS TIME. WED COULD BE VERY WARM
ESPECIALLY IF ANY SUNNY BREAKS ARE OBSERVED AND W WINDS ARE
EXPECTED BY THE AFTERNOON. HOWEVER...BY THE OVERNIGHT
PERIOD...COLD ADVECTION WILL HAVE BEGUN ALOFT...LOWERING THE
DENDRITE ZONE. THEREFORE...YET ANOTHER ROUND OF LIGHT TO MODERATE
SNOW IS POSSIBLE...WITH ACCUMS POSSIBLY REACHING ADVISORY LVL ON
TOP OF THE SNOW AND ICE FROM THE PREVIOUS 24 HOURS. QPF VALUES OF
0.3-0.5 ARE PROGGED...WHICH WOULD SUGGEST EASY ACCUMS TO ADVISORY
LVL. IT APPEARS THE PEAK WOULD BE MAINLY ALONG THE S COAST...AT
LEAST THAT/S WHERE F-GEN AND MOISTURE SEEM TO BE MOST COINCIDENT.

THU NIGHT INTO FRI...
STRONG ARCTIC HIGH PRES MAKES A TRIUMPHANT RETURN TO THE REGION
AS 1040+HPA IN THE MASS FIELDS COMBINE WITH -20C H85 TEMPS. EXPECT
ANOTHER PERIOD OF COLD WITH POTENTIAL FOR SUB-ZERO NIGHTS AND
HIGHS WELL BELOW NORMAL. IN FACT...CAN/T RULE OUT THE POTENTIAL
NEED FOR WIND CHILL HEADLINES THU NIGHT AS THIS IS WHEN PRES
GRADIENT APPEARS STRONG ENOUGH TO SUPPORT IT.

NEXT WEEKEND...
LOOKS MAINLY DRY AS HIGH PRES REMAINS IN CONTROL COULD SEE A WEAK
UPPER DISTURBANCE AND ATTENDANT COLD FRONT ATTEMPT TO MAKE A
PASSAGE. HOWEVER...VERY DRY AIRMASS IN PLACE COULD PREEMPT ANY
PRECIPITATION ATTEMPTS.

EARLY NEXT WEEK...
HINTS AT ANOTHER POTENTIAL MODERATE LOW PRES WITH PRECIP IN
TOW...HOWEVER LOTS OF UNCERTAINTY AS TO TIMING OR P-TYPES AT THIS
TIME.

&&

.AVIATION /09Z MONDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TODAY THROUGH TUESDAY/...

TODAY...HIGH CONFIDENCE.  LINGERING IFR CONDITIONS ACROSS
CAPE/ISLANDS SHOULD IMPROVE TO VFR BY 11 OR 12Z.  OTHERWISE...EXPECT
VFR CONDITIONS TODAY DESPITE A SCATTERED TO EVEN BROKEN DECK OF
STRATO-CUMULUS CLOUDS.  WEST TO NORTHWEST WIND GUSTS OF 25 TO 35 ARE
EXPECTED TO DEVELOP LATER THIS MORNING AND CONTINUE INTO THE
AFTERNOON.

TONIGHT...HIGH CONFIDENCE.  WINDS GRADUALLY DIMINISH THIS EVENING
WITH VFR CONDITIONS CONTINUING.

TUESDAY...MODERATE TO HIGH CONFIDENCE.  VFR CONDITIONS
THROUGH AT LEAST MID AFTERNOON.  MVFR-IFR CONDITIONS MAY DEVELOP BY
LATE TUE AFTERNOON OR EARLY TUE EARLY EVENING ACROSS WESTERN
MA/NORTHERN CT AS LIGHT SNOW DEVELOPS.

KBOS TAF...HIGH CONFIDENCE.  NORTHWEST WIND GUSTS OF 25 TO 35 KNOTS
DEVELOP LATER THIS MORNING AND CONTINUE INTO THE AFTERNOON.

KBDL TAF...HIGH CONFIDENCE.  NORTHWEST WIND GUSTS OF 25 TO 35 KNOTS
DEVELOP LATER THIS MORNING AND CONTINUE INTO THE AFTERNOON.

OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY...

TUE NIGHT INTO WED...HIGH CONFIDENCE.
PERIODS OF IFR AND OCCASIONAL IFR POSSIBLE. SNOW TO
START...TRANSITIONING TO SLEET THEN FREEZING RAIN...THEN STRAIGHT
RAIN THROUGH THE OVERNIGHT AND EARLY MORNING HOURS. SNOW ACCUMS
GENERALLY 1-4 INCHES...ICE ACCUMS A TRACE TO A TENTH OF AN INCH
POSSIBLE. SOUTHERLY WINDS WITH LLWS LIKELY.

WED NIGHT INTO THU...MODERATE CONFIDENCE.
AFTER A LULL IN PRECIP EARLY WED...A PERIOD OF RAIN TRANSITIONING
TO SNOW IS POSSIBLE...ESPECIALLY TOWARD THE SOUTH COAST. VFR
LIKELY NORTH...IFR LIKELY IN SNOWFALL.

FRI...HIGH CONFIDENCE.
CONDITIONS IMPROVE. VFR LIKELY.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TODAY THROUGH TUESDAY/...

TODAY AND TONIGHT...HIGH CONFIDENCE.  A COLD FRONT CROSSES THE
REGION EARLY THIS MORNING AND WINDS WILL PICKUP QUICKLY AFTER
SUNRISE.  NORTHWEST WIND GUSTS OF 35 TO 40 KNOTS WILL DEVELOP BY
LATE MORNING AND CONTINUE INTO THE EVENING IN THE COLD AIR ADVECTION
PATTERN.  GALE WARNINGS POSTED FOR ALL WATERS.  WINDS WILL BEGIN TO
DIMINISH FOR THE SECOND HALF OF THE NIGHT AS HIGH PRESSURE BEGINS TO
BUILD IN FROM THE WEST.  IN ADDITION...WIDESPREAD LIGHT FREEZING
SPRAY EXPECTED TONIGHT.

TUESDAY...HIGH CONFIDENCE.  WINDS WILL HAVE DROPPED BELOW SMALL
CRAFT ADVISORY THRESHOLDS BY EARLY MORNING AS HIGH PRESSURE BUILDS
ACROSS THE WATERS. HOWEVER...LEFT OVER SWELL WILL KEEP SMALL CRAFT
SEAS GOING ACROSS THE OUTER-WATERS UNTIL AROUND NOON.

OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY..MODERATE CONFIDENCE.

TUE NIGHT INTO WED...
LOW PRES MOVES WELL INLAND...WITH A PERIOD OF SNOW RAPIDLY
CHANGING TO SLEET THEN RAIN ACROSS THE WATERS OVERNIGHT TUE NIGHT.
LOW VSBYS EXPECTED. SLY WINDS GUST TO AROUND 25 KT AT TIMES WITH
SEAS INCREASING 5-8 FT BY WED MORNING ON THE OCEAN WATERS. SMALL
CRAFT ADVISORIES LIKELY.

WED NIGHT INTO THU NIGHT...
ANOTHER WAVE OF LOW PRES MOVES ALONG A STALLED FRONTAL BOUNDARY
OVER THE WATERS. PRECIP CONTINUES. NW WINDS CONTINUE TO GUST 25
KT. ALSO...SEAS REMAIN ELEVATED 5-8FT. SMALL CRAFT ADVISORIES
LIKELY CONTINUE.

FRI...
CONDITIONS IMPROVE...SMALL CRAFT ADVISORIES MAY BE ABLE TO BE
TAKEN DOWN.


&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...GALE WARNING FROM 11 AM THIS MORNING TO 1 AM EST TUESDAY FOR
     ANZ231-232-250-251-254-255.
     GALE WARNING FROM 11 AM THIS MORNING TO 11 PM EST THIS EVENING
     FOR ANZ233>235-237-256.
     GALE WARNING FROM 11 AM THIS MORNING TO 8 PM EST THIS EVENING
     FOR ANZ230-236.

&&

$$
SYNOPSIS...FRANK/DOODY
NEAR TERM...FRANK
SHORT TERM...FRANK
LONG TERM...DOODY
AVIATION...FRANK/DOODY
MARINE...FRANK/DOODY



000
FXUS61 KGYX 020810
AFDGYX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
310 AM EST MON MAR 2 2015

.SYNOPSIS...
BREEZY BUT RELATIVELY MILD WEATHER EXPECTED TODAY AS LOW PRESSURE
TRACKS NORTHEAST ACROSS THE MARITIME PROVINCES. HIGH PRESSURE
BUILDS IN FROM THE WEST TONIGHT AND SHIFTS OFFSHORE BY TUESDAY
AFTERNOON. LOW PRESSURE WILL SWING THROUGH SOUTHERN CANADA
TUESDAY NIGHT PUSHING A WARM FRONT NORTH ACROSS THE REGION...AND
PRODUCING A PERIOD OF SNOW AND MIXED RAIN OR SNOW ALONG THE COAST.
AS THE LOW SHIFTS TO OUR NORTH...IT WILL DRAG A COLD FRONT THROUGH
THE REGION LATE WEDNESDAY. HIGH PRESSURE WILL BUILD IN FROM THE
WEST THURSDAY AND WILL CREST OVER THE REGION ON FRIDAY.

&&

.NEAR TERM /THROUGH TODAY/...
FOR THE MOST PART...THE FINAL BIT OF LIGHT SNOW ASSOCIATED WITH
THE OFFSHORE SFC LOW WILL BE EXITING THE ERN ZONES BY 09Z. 500 MB
TROUGH AXIS IS HANGING BACK AND WILL CROSS THE NRN CWA BETWEEN 15
AND 18Z. THIS WILL BRING A ROUND OF SHSN TO THE MTNS AND WILL BE
ENHANCED BY UPSLOPE LATER THIS MORNING INTO AT LEAST THE FIRST
HALF OF THE AFTERNOON. ACTUALLY...MESO MODELS ALSO SUGGEST A FEW
SHSN OR FLURRIES ACROSS THE ERN ZONES AROUND MIDDAY WITH THIS
FEATURE AS WELL....ALTHOUGH DON`T REALLY EXPECT ANY ACCUMS HERE.
HOWEVER IN THE UPSLOPE AREAS COULD SEE A FEW INCHES IN THE LOCALLY
FAVORED AREAS. DESPITE ALL THE COLD THIS YEAR...UPSLOPE SNOW EVENT
HAVE BEEN QUITE LIMITED AS MOST OF THESE 500MB SYSTEMS HAVE BEEN
DEEP OR CLOSED OFF TROUGHS WHICH DRAG ALL THE ENERGY TO OUR EAST
AND PULL DRY AIR IN QUICKLY BEHIND THE MAIN SYSTEM...LEAVING VERY
LITTLE IN THE WAY OF DYNAMICS OR INSTABILITY TO ENHANCE THE
UPSLOPE.

ON THE COASTAL PLAIN...THIS TROUGH WILL KEEP THE CLOUDS
AROUND...AT LEAST FOR M/CDY CONDS THRU THE MORNING...BEFORE THE
WINDS KICK IN AND THE DOWNSLOPE BEGINS WHICH SHOULD CLEAR THINGS
OUT DURING THE AFTERNOON. SHOULD WARM UP NICELY HERE AS
WELL...WITH HIGHS IN THE MID-UPPER 30S.

&&

.SHORT TERM /TONIGHT THROUGH 6 PM TUESDAY/...
THE [PRES GRADIENT HOLDS UP THRU THE EVENING HOURS...AND THE
BREEZY CONDS WILL CONTINUE THRU THE FIRST PART OF THE EVENING
BEFORE THEY START TO DIMINISH AS THE HIGH MOVES TO OUR S. COLDER
AIR WILL MOVE IN AND SHOULD SEE SOME OF THE SHELTERED DECOUPLE
FOR THE SECOND HALF OF THE NIGHT...WITH LOWS IN SINGLE DIGITS BLO
ZERO IN THE N...AND SINGLE DIGITS TO AROUND 10 ABV ELSEWHERE.

ON TUESDAY THE HIGH WILL PASS JUST TO OUR S IN THE MORNING AND
THAN SHIFT OFF SHORE BY LATE IN THE DAY. THIS WILL KEEP FLOW
LIGHT...AND WITH MID-HIGH CLOUDS MOVING IN FROM THE NEXT SYSTEM
HIGHS WILL BE LIMITED TO THE 20S. PRECIP WILL LKLY HOLD OFF UNTIL
AFTER SUNSET...BUT A LITTLE LIGHT SN COULD BREAK OUT IN SW NH FOR
THE EVENING COMMUTE.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
IN SHORT...A CONTINUATION OF BELOW NORMAL TEMPERATURES AND NO
HEAVY PRECIPITATION EVENTS. THE MODELS ARE IN GENERAL AGREEMENT
ON THE LONG WAVE PATTERN WELL INTO NEXT WEEK. THE WESTERN RIDGE
GRADUALLY FLATTENS AND MOVES ONSHORE INTO THE WESTERN HALF OF THE
CONUS...WHILE WE SEE LINGERING TROFINESS HERE IN THE EAST AND
BELOW NORMAL TEMPERATURES...PUNCTUATED BY PERIODIC BRIEF WARM UPS.
WE BEGIN THE PERIOD WITH AN IMPULSE RACING EASTWARD FROM THE
NORTHERN PLAINS INTO NEW ENGLAND. A QUICK OVERRUNNING EVENT WITH
LIGHT MIXED PRECIPITATION TUESDAY NIGHT FOLLOWED BY A BRIEF WARM
UP ON WEDNESDAY AHEAD OF A COLD FRONT. SCATTERED UPSLOPE SNOW
SHOWERS FOLLOW FOR WEDNESDAY NIGHT AND THURSDAY. HIGH PRESSURE
BUILDS EAST ACROSS THE AREA FRIDAY. A WEAK DISTURBANCE WILL DRAG
TRAILING WARM AND COLD FRONTS ACROSS THE REGION NEXT WEEKEND.
ANOTHER COLD FRONT WILL CROSS THE AREA ERALY NEXT WEEK.

&&

.AVIATION /08Z MONDAY THROUGH FRIDAY/...
SHORT TERM...COULD STILL SEE SOME MVFR THRU ABOUT SUNRISE...AND
MAYBE LOWER IN FOG AT KCON...BUT ALL LOCATIONS SHOULD IMPROVE VFR
AFTER SUNRISE...WITH THE EXCEPTION OF KHIE...WHICH COULD LINGER AT
MVFR THOUGH TODAY...AND MAY GO LOWER BRIEFLY IS SHSN. ALL
TERMINALS SHOULD EXPECT VFR TONIGHT AND TUE.

LONG TERM...

TUE NIGHT - WED...MVFR WITH LCL IFR IN LIGHT MIXED PRECIPITATION.

THU...SCT MVFR IN MTN SNOW SHOWERS.

&&

.MARINE...
SHORT TERM...HAVE EXTENDED THE GALES THRU THE OVERNIGHT
TONIGHT...AS THE PRES GRADIENT LOOKS TO HOLD A LITTLE
LONGER...ESPECIALLY E OF CASCO BAY. BUT AS HIGH PRES BUILDS IN
WINDS WILL DIMINISH QUICKLY EARLY TUE MORNING. AS THE WINDS PICK
UP THIS AFTERNOON AND THE TEMPS DROPS THIS EVE...LOOK FOR ANOTHER
ROUND OF LIGHT FZ SPRAY TONIGHT INTO EARLY TUE.

LONG TERM...

TUE NIGHT - WED...GALE FORCE WINDS ARE POSSIBLE.

THU - FRI...SMALL CRAFT WINDS AND SEAS ARE POSSIBLE.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY FROM NOON TODAY TO 3 AM EST TUESDAY FOR
     ANZ151-153.
     GALE WARNING FROM NOON TODAY TO 3 AM EST TUESDAY FOR ANZ150-
     152-154.

&&

$$
SYNOPSIS...
NEAR TERM...CEMPA
SHORT TERM...CEMPA
LONG TERM...SCHWIBS
AVIATION...
MARINE...




000
FXUS61 KGYX 020810
AFDGYX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
310 AM EST MON MAR 2 2015

.SYNOPSIS...
BREEZY BUT RELATIVELY MILD WEATHER EXPECTED TODAY AS LOW PRESSURE
TRACKS NORTHEAST ACROSS THE MARITIME PROVINCES. HIGH PRESSURE
BUILDS IN FROM THE WEST TONIGHT AND SHIFTS OFFSHORE BY TUESDAY
AFTERNOON. LOW PRESSURE WILL SWING THROUGH SOUTHERN CANADA
TUESDAY NIGHT PUSHING A WARM FRONT NORTH ACROSS THE REGION...AND
PRODUCING A PERIOD OF SNOW AND MIXED RAIN OR SNOW ALONG THE COAST.
AS THE LOW SHIFTS TO OUR NORTH...IT WILL DRAG A COLD FRONT THROUGH
THE REGION LATE WEDNESDAY. HIGH PRESSURE WILL BUILD IN FROM THE
WEST THURSDAY AND WILL CREST OVER THE REGION ON FRIDAY.

&&

.NEAR TERM /THROUGH TODAY/...
FOR THE MOST PART...THE FINAL BIT OF LIGHT SNOW ASSOCIATED WITH
THE OFFSHORE SFC LOW WILL BE EXITING THE ERN ZONES BY 09Z. 500 MB
TROUGH AXIS IS HANGING BACK AND WILL CROSS THE NRN CWA BETWEEN 15
AND 18Z. THIS WILL BRING A ROUND OF SHSN TO THE MTNS AND WILL BE
ENHANCED BY UPSLOPE LATER THIS MORNING INTO AT LEAST THE FIRST
HALF OF THE AFTERNOON. ACTUALLY...MESO MODELS ALSO SUGGEST A FEW
SHSN OR FLURRIES ACROSS THE ERN ZONES AROUND MIDDAY WITH THIS
FEATURE AS WELL....ALTHOUGH DON`T REALLY EXPECT ANY ACCUMS HERE.
HOWEVER IN THE UPSLOPE AREAS COULD SEE A FEW INCHES IN THE LOCALLY
FAVORED AREAS. DESPITE ALL THE COLD THIS YEAR...UPSLOPE SNOW EVENT
HAVE BEEN QUITE LIMITED AS MOST OF THESE 500MB SYSTEMS HAVE BEEN
DEEP OR CLOSED OFF TROUGHS WHICH DRAG ALL THE ENERGY TO OUR EAST
AND PULL DRY AIR IN QUICKLY BEHIND THE MAIN SYSTEM...LEAVING VERY
LITTLE IN THE WAY OF DYNAMICS OR INSTABILITY TO ENHANCE THE
UPSLOPE.

ON THE COASTAL PLAIN...THIS TROUGH WILL KEEP THE CLOUDS
AROUND...AT LEAST FOR M/CDY CONDS THRU THE MORNING...BEFORE THE
WINDS KICK IN AND THE DOWNSLOPE BEGINS WHICH SHOULD CLEAR THINGS
OUT DURING THE AFTERNOON. SHOULD WARM UP NICELY HERE AS
WELL...WITH HIGHS IN THE MID-UPPER 30S.

&&

.SHORT TERM /TONIGHT THROUGH 6 PM TUESDAY/...
THE [PRES GRADIENT HOLDS UP THRU THE EVENING HOURS...AND THE
BREEZY CONDS WILL CONTINUE THRU THE FIRST PART OF THE EVENING
BEFORE THEY START TO DIMINISH AS THE HIGH MOVES TO OUR S. COLDER
AIR WILL MOVE IN AND SHOULD SEE SOME OF THE SHELTERED DECOUPLE
FOR THE SECOND HALF OF THE NIGHT...WITH LOWS IN SINGLE DIGITS BLO
ZERO IN THE N...AND SINGLE DIGITS TO AROUND 10 ABV ELSEWHERE.

ON TUESDAY THE HIGH WILL PASS JUST TO OUR S IN THE MORNING AND
THAN SHIFT OFF SHORE BY LATE IN THE DAY. THIS WILL KEEP FLOW
LIGHT...AND WITH MID-HIGH CLOUDS MOVING IN FROM THE NEXT SYSTEM
HIGHS WILL BE LIMITED TO THE 20S. PRECIP WILL LKLY HOLD OFF UNTIL
AFTER SUNSET...BUT A LITTLE LIGHT SN COULD BREAK OUT IN SW NH FOR
THE EVENING COMMUTE.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
IN SHORT...A CONTINUATION OF BELOW NORMAL TEMPERATURES AND NO
HEAVY PRECIPITATION EVENTS. THE MODELS ARE IN GENERAL AGREEMENT
ON THE LONG WAVE PATTERN WELL INTO NEXT WEEK. THE WESTERN RIDGE
GRADUALLY FLATTENS AND MOVES ONSHORE INTO THE WESTERN HALF OF THE
CONUS...WHILE WE SEE LINGERING TROFINESS HERE IN THE EAST AND
BELOW NORMAL TEMPERATURES...PUNCTUATED BY PERIODIC BRIEF WARM UPS.
WE BEGIN THE PERIOD WITH AN IMPULSE RACING EASTWARD FROM THE
NORTHERN PLAINS INTO NEW ENGLAND. A QUICK OVERRUNNING EVENT WITH
LIGHT MIXED PRECIPITATION TUESDAY NIGHT FOLLOWED BY A BRIEF WARM
UP ON WEDNESDAY AHEAD OF A COLD FRONT. SCATTERED UPSLOPE SNOW
SHOWERS FOLLOW FOR WEDNESDAY NIGHT AND THURSDAY. HIGH PRESSURE
BUILDS EAST ACROSS THE AREA FRIDAY. A WEAK DISTURBANCE WILL DRAG
TRAILING WARM AND COLD FRONTS ACROSS THE REGION NEXT WEEKEND.
ANOTHER COLD FRONT WILL CROSS THE AREA ERALY NEXT WEEK.

&&

.AVIATION /08Z MONDAY THROUGH FRIDAY/...
SHORT TERM...COULD STILL SEE SOME MVFR THRU ABOUT SUNRISE...AND
MAYBE LOWER IN FOG AT KCON...BUT ALL LOCATIONS SHOULD IMPROVE VFR
AFTER SUNRISE...WITH THE EXCEPTION OF KHIE...WHICH COULD LINGER AT
MVFR THOUGH TODAY...AND MAY GO LOWER BRIEFLY IS SHSN. ALL
TERMINALS SHOULD EXPECT VFR TONIGHT AND TUE.

LONG TERM...

TUE NIGHT - WED...MVFR WITH LCL IFR IN LIGHT MIXED PRECIPITATION.

THU...SCT MVFR IN MTN SNOW SHOWERS.

&&

.MARINE...
SHORT TERM...HAVE EXTENDED THE GALES THRU THE OVERNIGHT
TONIGHT...AS THE PRES GRADIENT LOOKS TO HOLD A LITTLE
LONGER...ESPECIALLY E OF CASCO BAY. BUT AS HIGH PRES BUILDS IN
WINDS WILL DIMINISH QUICKLY EARLY TUE MORNING. AS THE WINDS PICK
UP THIS AFTERNOON AND THE TEMPS DROPS THIS EVE...LOOK FOR ANOTHER
ROUND OF LIGHT FZ SPRAY TONIGHT INTO EARLY TUE.

LONG TERM...

TUE NIGHT - WED...GALE FORCE WINDS ARE POSSIBLE.

THU - FRI...SMALL CRAFT WINDS AND SEAS ARE POSSIBLE.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY FROM NOON TODAY TO 3 AM EST TUESDAY FOR
     ANZ151-153.
     GALE WARNING FROM NOON TODAY TO 3 AM EST TUESDAY FOR ANZ150-
     152-154.

&&

$$
SYNOPSIS...
NEAR TERM...CEMPA
SHORT TERM...CEMPA
LONG TERM...SCHWIBS
AVIATION...
MARINE...



000
FXUS61 KBOX 020601
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
100 AM EST MON MAR 2 2015

.SYNOPSIS...

DRY AND BLUSTERY WEATHER TODAY BEHIND A COLD FRONT. LOW PRESSURE
FROM NORTHERN CANADA AND ASSOCIATED LOW FORMING OVER THE PLAINS
MONDAY WILL MERGE...THEN PASS WEST AND NORTH OF NEW ENGLAND. THIS
WILL SWING A COLD FRONT ACROSS THE REGION ON WEDNESDAY. DRY AND COLD
WEATHER RETURNS FOR THE END OF THE WEEK. ANOTHER COLD FRONT MOVES
THROUGH ON SATURDAY.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...

1 AM UPDATE...

LAST GASP OF SNOW ACROSS RHODE ISLAND AND EASTERN MA WILL BE QUICKLY
EXITING THE REGION IN THE NEXT HOUR.  PTYPE HAS CHANGED TO
RAIN ACROSS THE CAPE/ISLANDS AND THAT WILL ALSO BE ENDING SHORTLY.
WE SHOULD BE ABLE TO TAKE DOWN ALL THE WINTER WEATHER HEADLINES
VERY SHORTLY.

OTHERWISE...AN ABUNDANCE OF MID LEVEL CLOUDINESS WILL HANG TOUGH
OVERNIGHT.  A COLD FRONT WILL CROSS THE REGION TOWARD MORNING...BUT
THE WINDS WILL NOT PICKUP TOO MUCH UNTIL AFTER SUNRISE.  LOW TEMPS
WILL GENERALLY REMAIN IN THE 20S WITH A LOT OF CLOUDS PERSISTING.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM TUESDAY/...
MONDAY...
PRECIPITATION WILL HAVE LARGELY COME TO AN END FOR DAYBREAK MONDAY
WITH THE LOW PRESSURE RAPIDLY PULLING AWAY INTO THE CANADIAN
MARITIMES AND DRIER AIR/HIGH PRESSURE MOVING IN FROM THE WEST.
INCREASING SUNSHINE EXPECTED DURING THE DAY...WITH TEMPS TOPPING
OUT IN THE UPPER 20S TO MID 30S. HOWEVER AS WE GET TOWARDS
MIDDAY/AFTERNOON TIGHTENING GRADIENT WILL ALLOW NORTHWEST FLOW TO
BECOME BLUSTERY...WITH GUSTS OF 25 TO 30 MPH...25 TO 35 MPH ON THE
CAPE AND ISLANDS.

MONDAY NIGHT...
HIGH PRESSURE SETTLES OVER THE AREA WITH CLEAR SKIES EXPECTED.
GIVEN OUR SNOWPACK IN PLACE AND LIGHT WINDS...SHOULD BE ANOTHER
NIGHT FOR EXCELLENT RADIATIONAL COOLING. BECAUSE OF THIS DID
GENERALLY GO BELOW MODEL GUIDANCE FOR MIN TEMPS...LOOKING TO
ANTICIPATED SURFACE DEWPOINTS FOR A GUIDELINE ON HOW LOW WE CAN
GO. MAY SEE SOME SPOTS IN THE INTERIOR DROP BELOW ZERO.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
BIG PICTURE... THE BROAD UPPER FLOW CONTINUES TO FEATURE A TROUGH
TRANSITING EAST ACROSS THE COUNTRY...REACHING THE EASTERN USA DURING
THE LATE WEEK AND LINGERING THROUGH THE WEEKEND. MEANWHILE AN UPPER
RIDGE SHIFTS FROM THE PACIFIC OCEAN BACK ASHORE ONTO THE WEST COAST.
CONTOUR HEIGHTS IN THE TROUGH ARE LOWEST THURSDAY-FRIDAY AND NEAR
NORMAL OVER THE WEEKEND. THIS MEANS A TREND TO COLDER TEMPS THURSDAY-
FRIDAY FOLLOWED BY A TREND CLOSER TO NORMAL OVER THE WEEKEND.

DAILIES...

TUESDAY... HIGH PRESSURE OVER THE REGION MOVES OFFSHORE BY AFTERNOON
WITH AIRFLOW SWINGING FROM NORTHWEST TO SOUTHWEST. THE SURFACE
AIRMASS STARTS OUT QUITE DRY WITH DEW POINTS IN THE SINGLE NUMBERS
BELOW ZERO TO START...CLIMBING TO 5-10 ABOVE BY EVENING. MODEL CROSS
SECTIONS SHOW INCREASING MOISTURE MORNING AND AFTERNOON ABOVE 700
MB. THIS SUGGESTS INCREASING MID AND HIGH CLOUDS WHILE DRY BENEATH.
LOW LEVEL JETS FROM THE CAROLINAS AND MIDWEST AND THE SURFACE
PRESSURE GRADIENT ALL SUGGEST THE INFLOW AND ISENTROPIC LIFT WILL
REMAIN TO OUR WEST THROUGH THE DAY...POSSIBLY ENTERING WESTERN MA/CT
AT OR AFTER 21Z. SO WE EXPECT INCREASING CLOUDS TUESDAY BUT
OTHERWISE DRY WEATHER THROUGH THE DAY. POSSIBLE LIGHT SNOW AROUND
THE EVENING RUSH HOUR IN THE CT RIVER VALLEY. TEMPS SHOULD REACH THE
MID 20S TO AROUND 30.

TUESDAY NIGHT-WEDNESDAY... NORTHERN AND SOUTHERN STREAM SHORTWAVES
MERGE OVER THE GREAT LAKES AND TRACK INTO CANADA. THIS BRINGS A MILD
FLOW OF AIR UP OVER NEW ENGLAND. THE LEADING EDGE OF THIS AIR
REACHES WESTERN SECTIONS TUESDAY EVENING AND EASTERN SECTIONS
TUESDAY NIGHT. TEMPERATURE PROFILES SUPPORT AN INITIAL PERIOD OF
SNOW CHANGING TO RAIN OR FREEZING RAIN OVERNIGHT. ACTUALLY...THE
MODELS MAY NOT BE HANDLING WELL THE CHILLING MASS OF SNOW AND COLD
GROUND /A.K.A. THE GIANT ICECUBE/ WHICH WOULD MEAN THE ACTUAL MAX
SFC TEMPS WILL BE COOLER THAN MODEL FORECASTS. TEMPERATURES AT 925
AND 950 MB WILL BE IN THE 30S...SO EXPECT SURFACE TEMPS NO HIGHER
THAN THE LOWER 40S.

THE SURFACE LOW PRESSURE AREA PASSES WELL NORTH OF NEW ENGLAND
WEDNESDAY AND SWINGS A COLD FRONT THROUGH THE REGION DURING THE
AFTERNOON OR EVENING. MOISTURE CROSS SECTIONS SHOW DECREASING RH IN
THE LIFT AND NUCLEATION ZONES ALOFT WEDNESDAY MORNING...SO THE TREND
THROUGH THE DAY SHOULD BE TO DIMINISHING POPS.

THURSDAY-FRIDAY... THE WEDNESDAY COLD FRONT WILL ALIGN WITH THE
UPPER FLOW AS IT MOVES SOUTH OF NEW ENGLAND...SLOWING ITS OFFSHORE
PROGRESS TO A CRAWL. MEANWHILE WE WILL BE UNDER THE RIGHT ENTRANCE
REGION OF THE SUPPORTING UPPER JET...A SOURCE OF UPPER VENTING. THIS
SHOULD SUPPORT LINGERING CLOUDS AND A CHANCE OF PCPN...WITH TEMPS
SUPPORTIVE OF SNOW. BEST CHANCE SOUTH COAST...LESSER CHANCE FARTHER
NORTH. THE JET AND SURFACE FRONT SWEEP OFFSHORE THURSDAY NIGHT. HIGH
PRESSURE THEN MOVES OVER THE EASTERN USA FOR FRIDAY. TEMPS ALOFT
SUPPORT MAX SFC TEMPS IN THE 20S.

SATURDAY-SUNDAY... ANOTHER NORTHERN STREAM SHORTWAVE AND COLD FRONT
SWINGS THROUGH THE FLOW SATURDAY. CROSS SECTIONS SHOW SOME MOISTURE
ALOFT BUT MOST OF IT IS CONCENTRATED TO OUR NORTH.  ALSO JUST
LIMITED LIFT TO WORK ON THAT MOISTURE. WE WILL HAVE 25-50 PCT SKY
COVER AND NIL POPS. HIGH PRESSURE THEN BUILDS FOR SUNDAY.

&&

.AVIATION /06Z MONDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TODAY THROUGH TUESDAY/...

TODAY...HIGH CONFIDENCE.  LEFT OVER MVFR-IFR CONDITIONS IN LIGHT
SNOW SHOULD IMPROVE TO VFR BY 7 OR 8Z.  OTHERWISE...EXPECT VFR
CONDITIONS DESPITE A SCATTERED TO EVEN BROKEN DECK OF STRATO-CUMULUS
CLOUDS.  WEST TO NORTHWEST WIND GUSTS OF 25 TO 35 ARE EXPECTED TO
DEVELOP LATER THIS MORNING AND CONTINUE INTO THE AFTERNOON.

TONIGHT...HIGH CONFIDENCE.  WINDS GRADUALLY DIMINISH THIS EVENING
WITH VFR CONDITIONS CONTINUING.

TUESDAY...MODERATE TO HIGH CONFIDENCE.  VFR CONDITIONS
THROUGH AT LEAST MID AFTERNOON.  MVFR-IFR CONDITIONS MAY DEVELOP BY
LATE TUE AFTERNOON/EARLY EVENING ACROSS WESTERN MA/NORTHERN CT AS
SNOW OVERSPREADS THE REGION.

KBOS TAF...HIGH CONFIDENCE.  NORTHWEST WIND GUSTS OF 25 TO 35 KNOTS
LATER THIS MORNING AND AFTERNOON.

KBDL TAF...HIGH CONFIDENCE.  NORTHWEST WIND GUSTS OF 25 TO 35 KNOTS
LATER THIS MORNING AND AFTERNOON.

OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY...

TUESDAY NIGHT-WEDNESDAY...MODERATE CONFIDENCE. CONDITIONS LOWERING
TO IFR/LIFR. INITIALLY SNOW BUT CHANGING TO SLEET/FREEZING RAIN
DURING THE NIGHT AND RAIN IN THE COASTAL PLAIN OVERNIGHT. PCPN
CHANGES TO RAIN ALL AREAS WEDNESDAY...BUT COLD SURFACES COULD
MAINTAIN A FREEZING RAIN ELEMENT WEDNESDAY MORNING. COLDER AIR MOVES
IN WEDNESDAY NIGHT CHANGING ANY RAIN TO SNOW.

THURSDAY...LOW CONFIDENCE. VFR NORTH OF A HFD-BOS LINE. MVFR CIGS
AND AREAS OF MVFR/IFR VSBYS IN SNOW...DIMINISHING BY EVENING.
NORTHWEST WINDS GUSTING TO 20 KNOTS.

FRIDAY...MODERATE CONFIDENCE. VFR.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...HIGH CONFIDENCE.

A WEAK WAVE OF LOW PRESSURE MOVES ACROSS THE WATERS TONIGHT.
THIS SYSTEM REALLY INTENSIFIES AS IT MOVES INTO THE CANADIAN
MARITIMES NEAR DAYBREAK MONDAY...SO WESTERLY WIND GUSTS MAY REACH
20 TO 25 KNOTS NEAR 12Z MONDAY. OTHERWISE...RAIN AND SNOW THIS
EVENING AND TONIGHT WILL REDUCE VISIBILITIES AT TIMES FOR
MARINERS.

MONDAY...AS THE LOW PRESSURE GOING INTO THE CANADIAN MARITIMES
INTENSIFIES...INCREASING NORTHWEST WINDS ARE EXPECTED OVER THE
SOUTHERN NEW ENGLAND COASTAL WATERS...WITH GALE FORCE GUSTS
EXPECTED. GALE WARNINGS HAVE BEEN HOISTED FOR ALL COASTAL WATERS
FROM MIDDAY MONDAY INTO MONDAY NIGHT.

OUTLOOK...TUESDAY THROUGH FRIDAY..MODERATE CONFIDENCE.

TUESDAY... LINGERING 5 FOOT SEAS SOUTH AND EAST OF NANTUCKET IN THE
MORNING BUT DIMINISHING. NORTHWEST WINDS DIMINISHING FROM 20 KNOTS.
ANY SMALL CRAFT ADVISORY SHOULD END IN THE MORNING.

TUESDAY NIGHT-WEDNESDAY...SOUTH TO SOUTHWEST WINDS WILL INCREASE TO
20-25 KNOTS. SEAS WILL BUILD 6 TO 10 FEET ON THE OUTER WATERS AND ON
RI SOUND. REDUCED VSBYS...INITIALLY SNOW BUT CHANGING TO RAIN. A
SMALL CRAFT ADVISORY MAY BE NEEDED.

THURSDAY...NORTHWEST WIND GUSTING TO 25 KNOTS. SEAS 5 TO 8 FEET
MAINLY ON THE OUTER WATERS...DIMINISHING LATE. A SMALL CRAFT
ADVISORY MAY BE NEEDED.

FRIDAY... SHIFTING WINDS LESS THAN 20 KNOTS. SEAS LESS THAN 5 FEET.
QUIET WEATHER.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WINTER WEATHER ADVISORY UNTIL 4 AM EST EARLY THIS MORNING FOR
     CTZ002>004.
MA...WINTER STORM WARNING UNTIL 4 AM EST EARLY THIS MORNING FOR
     MAZ017>021.
     WINTER WEATHER ADVISORY UNTIL 4 AM EST EARLY THIS MORNING FOR
     MAZ002>016-022-023-026.
RI...WINTER STORM WARNING UNTIL 4 AM EST EARLY THIS MORNING FOR
     RIZ002>008.
     WINTER WEATHER ADVISORY UNTIL 4 AM EST EARLY THIS MORNING FOR
     RIZ001.
MARINE...GALE WARNING FROM 11 AM THIS MORNING TO 4 AM EST TUESDAY FOR
     ANZ231-232-250-251-254-255.
     GALE WARNING FROM 11 AM THIS MORNING TO 11 PM EST THIS EVENING
     FOR ANZ233>235-237-256.
     GALE WARNING FROM 11 AM THIS MORNING TO 8 PM EST THIS EVENING
     FOR ANZ230-236.

&&

$$
SYNOPSIS...WTB/NMB
NEAR TERM...FRANK
SHORT TERM...NMB
LONG TERM...WTB
AVIATION...FRANK/WTB
MARINE...WTB/NMB



000
FXUS61 KBOX 020601
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
100 AM EST MON MAR 2 2015

.SYNOPSIS...

DRY AND BLUSTERY WEATHER TODAY BEHIND A COLD FRONT. LOW PRESSURE
FROM NORTHERN CANADA AND ASSOCIATED LOW FORMING OVER THE PLAINS
MONDAY WILL MERGE...THEN PASS WEST AND NORTH OF NEW ENGLAND. THIS
WILL SWING A COLD FRONT ACROSS THE REGION ON WEDNESDAY. DRY AND COLD
WEATHER RETURNS FOR THE END OF THE WEEK. ANOTHER COLD FRONT MOVES
THROUGH ON SATURDAY.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...

1 AM UPDATE...

LAST GASP OF SNOW ACROSS RHODE ISLAND AND EASTERN MA WILL BE QUICKLY
EXITING THE REGION IN THE NEXT HOUR.  PTYPE HAS CHANGED TO
RAIN ACROSS THE CAPE/ISLANDS AND THAT WILL ALSO BE ENDING SHORTLY.
WE SHOULD BE ABLE TO TAKE DOWN ALL THE WINTER WEATHER HEADLINES
VERY SHORTLY.

OTHERWISE...AN ABUNDANCE OF MID LEVEL CLOUDINESS WILL HANG TOUGH
OVERNIGHT.  A COLD FRONT WILL CROSS THE REGION TOWARD MORNING...BUT
THE WINDS WILL NOT PICKUP TOO MUCH UNTIL AFTER SUNRISE.  LOW TEMPS
WILL GENERALLY REMAIN IN THE 20S WITH A LOT OF CLOUDS PERSISTING.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM TUESDAY/...
MONDAY...
PRECIPITATION WILL HAVE LARGELY COME TO AN END FOR DAYBREAK MONDAY
WITH THE LOW PRESSURE RAPIDLY PULLING AWAY INTO THE CANADIAN
MARITIMES AND DRIER AIR/HIGH PRESSURE MOVING IN FROM THE WEST.
INCREASING SUNSHINE EXPECTED DURING THE DAY...WITH TEMPS TOPPING
OUT IN THE UPPER 20S TO MID 30S. HOWEVER AS WE GET TOWARDS
MIDDAY/AFTERNOON TIGHTENING GRADIENT WILL ALLOW NORTHWEST FLOW TO
BECOME BLUSTERY...WITH GUSTS OF 25 TO 30 MPH...25 TO 35 MPH ON THE
CAPE AND ISLANDS.

MONDAY NIGHT...
HIGH PRESSURE SETTLES OVER THE AREA WITH CLEAR SKIES EXPECTED.
GIVEN OUR SNOWPACK IN PLACE AND LIGHT WINDS...SHOULD BE ANOTHER
NIGHT FOR EXCELLENT RADIATIONAL COOLING. BECAUSE OF THIS DID
GENERALLY GO BELOW MODEL GUIDANCE FOR MIN TEMPS...LOOKING TO
ANTICIPATED SURFACE DEWPOINTS FOR A GUIDELINE ON HOW LOW WE CAN
GO. MAY SEE SOME SPOTS IN THE INTERIOR DROP BELOW ZERO.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
BIG PICTURE... THE BROAD UPPER FLOW CONTINUES TO FEATURE A TROUGH
TRANSITING EAST ACROSS THE COUNTRY...REACHING THE EASTERN USA DURING
THE LATE WEEK AND LINGERING THROUGH THE WEEKEND. MEANWHILE AN UPPER
RIDGE SHIFTS FROM THE PACIFIC OCEAN BACK ASHORE ONTO THE WEST COAST.
CONTOUR HEIGHTS IN THE TROUGH ARE LOWEST THURSDAY-FRIDAY AND NEAR
NORMAL OVER THE WEEKEND. THIS MEANS A TREND TO COLDER TEMPS THURSDAY-
FRIDAY FOLLOWED BY A TREND CLOSER TO NORMAL OVER THE WEEKEND.

DAILIES...

TUESDAY... HIGH PRESSURE OVER THE REGION MOVES OFFSHORE BY AFTERNOON
WITH AIRFLOW SWINGING FROM NORTHWEST TO SOUTHWEST. THE SURFACE
AIRMASS STARTS OUT QUITE DRY WITH DEW POINTS IN THE SINGLE NUMBERS
BELOW ZERO TO START...CLIMBING TO 5-10 ABOVE BY EVENING. MODEL CROSS
SECTIONS SHOW INCREASING MOISTURE MORNING AND AFTERNOON ABOVE 700
MB. THIS SUGGESTS INCREASING MID AND HIGH CLOUDS WHILE DRY BENEATH.
LOW LEVEL JETS FROM THE CAROLINAS AND MIDWEST AND THE SURFACE
PRESSURE GRADIENT ALL SUGGEST THE INFLOW AND ISENTROPIC LIFT WILL
REMAIN TO OUR WEST THROUGH THE DAY...POSSIBLY ENTERING WESTERN MA/CT
AT OR AFTER 21Z. SO WE EXPECT INCREASING CLOUDS TUESDAY BUT
OTHERWISE DRY WEATHER THROUGH THE DAY. POSSIBLE LIGHT SNOW AROUND
THE EVENING RUSH HOUR IN THE CT RIVER VALLEY. TEMPS SHOULD REACH THE
MID 20S TO AROUND 30.

TUESDAY NIGHT-WEDNESDAY... NORTHERN AND SOUTHERN STREAM SHORTWAVES
MERGE OVER THE GREAT LAKES AND TRACK INTO CANADA. THIS BRINGS A MILD
FLOW OF AIR UP OVER NEW ENGLAND. THE LEADING EDGE OF THIS AIR
REACHES WESTERN SECTIONS TUESDAY EVENING AND EASTERN SECTIONS
TUESDAY NIGHT. TEMPERATURE PROFILES SUPPORT AN INITIAL PERIOD OF
SNOW CHANGING TO RAIN OR FREEZING RAIN OVERNIGHT. ACTUALLY...THE
MODELS MAY NOT BE HANDLING WELL THE CHILLING MASS OF SNOW AND COLD
GROUND /A.K.A. THE GIANT ICECUBE/ WHICH WOULD MEAN THE ACTUAL MAX
SFC TEMPS WILL BE COOLER THAN MODEL FORECASTS. TEMPERATURES AT 925
AND 950 MB WILL BE IN THE 30S...SO EXPECT SURFACE TEMPS NO HIGHER
THAN THE LOWER 40S.

THE SURFACE LOW PRESSURE AREA PASSES WELL NORTH OF NEW ENGLAND
WEDNESDAY AND SWINGS A COLD FRONT THROUGH THE REGION DURING THE
AFTERNOON OR EVENING. MOISTURE CROSS SECTIONS SHOW DECREASING RH IN
THE LIFT AND NUCLEATION ZONES ALOFT WEDNESDAY MORNING...SO THE TREND
THROUGH THE DAY SHOULD BE TO DIMINISHING POPS.

THURSDAY-FRIDAY... THE WEDNESDAY COLD FRONT WILL ALIGN WITH THE
UPPER FLOW AS IT MOVES SOUTH OF NEW ENGLAND...SLOWING ITS OFFSHORE
PROGRESS TO A CRAWL. MEANWHILE WE WILL BE UNDER THE RIGHT ENTRANCE
REGION OF THE SUPPORTING UPPER JET...A SOURCE OF UPPER VENTING. THIS
SHOULD SUPPORT LINGERING CLOUDS AND A CHANCE OF PCPN...WITH TEMPS
SUPPORTIVE OF SNOW. BEST CHANCE SOUTH COAST...LESSER CHANCE FARTHER
NORTH. THE JET AND SURFACE FRONT SWEEP OFFSHORE THURSDAY NIGHT. HIGH
PRESSURE THEN MOVES OVER THE EASTERN USA FOR FRIDAY. TEMPS ALOFT
SUPPORT MAX SFC TEMPS IN THE 20S.

SATURDAY-SUNDAY... ANOTHER NORTHERN STREAM SHORTWAVE AND COLD FRONT
SWINGS THROUGH THE FLOW SATURDAY. CROSS SECTIONS SHOW SOME MOISTURE
ALOFT BUT MOST OF IT IS CONCENTRATED TO OUR NORTH.  ALSO JUST
LIMITED LIFT TO WORK ON THAT MOISTURE. WE WILL HAVE 25-50 PCT SKY
COVER AND NIL POPS. HIGH PRESSURE THEN BUILDS FOR SUNDAY.

&&

.AVIATION /06Z MONDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TODAY THROUGH TUESDAY/...

TODAY...HIGH CONFIDENCE.  LEFT OVER MVFR-IFR CONDITIONS IN LIGHT
SNOW SHOULD IMPROVE TO VFR BY 7 OR 8Z.  OTHERWISE...EXPECT VFR
CONDITIONS DESPITE A SCATTERED TO EVEN BROKEN DECK OF STRATO-CUMULUS
CLOUDS.  WEST TO NORTHWEST WIND GUSTS OF 25 TO 35 ARE EXPECTED TO
DEVELOP LATER THIS MORNING AND CONTINUE INTO THE AFTERNOON.

TONIGHT...HIGH CONFIDENCE.  WINDS GRADUALLY DIMINISH THIS EVENING
WITH VFR CONDITIONS CONTINUING.

TUESDAY...MODERATE TO HIGH CONFIDENCE.  VFR CONDITIONS
THROUGH AT LEAST MID AFTERNOON.  MVFR-IFR CONDITIONS MAY DEVELOP BY
LATE TUE AFTERNOON/EARLY EVENING ACROSS WESTERN MA/NORTHERN CT AS
SNOW OVERSPREADS THE REGION.

KBOS TAF...HIGH CONFIDENCE.  NORTHWEST WIND GUSTS OF 25 TO 35 KNOTS
LATER THIS MORNING AND AFTERNOON.

KBDL TAF...HIGH CONFIDENCE.  NORTHWEST WIND GUSTS OF 25 TO 35 KNOTS
LATER THIS MORNING AND AFTERNOON.

OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY...

TUESDAY NIGHT-WEDNESDAY...MODERATE CONFIDENCE. CONDITIONS LOWERING
TO IFR/LIFR. INITIALLY SNOW BUT CHANGING TO SLEET/FREEZING RAIN
DURING THE NIGHT AND RAIN IN THE COASTAL PLAIN OVERNIGHT. PCPN
CHANGES TO RAIN ALL AREAS WEDNESDAY...BUT COLD SURFACES COULD
MAINTAIN A FREEZING RAIN ELEMENT WEDNESDAY MORNING. COLDER AIR MOVES
IN WEDNESDAY NIGHT CHANGING ANY RAIN TO SNOW.

THURSDAY...LOW CONFIDENCE. VFR NORTH OF A HFD-BOS LINE. MVFR CIGS
AND AREAS OF MVFR/IFR VSBYS IN SNOW...DIMINISHING BY EVENING.
NORTHWEST WINDS GUSTING TO 20 KNOTS.

FRIDAY...MODERATE CONFIDENCE. VFR.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...HIGH CONFIDENCE.

A WEAK WAVE OF LOW PRESSURE MOVES ACROSS THE WATERS TONIGHT.
THIS SYSTEM REALLY INTENSIFIES AS IT MOVES INTO THE CANADIAN
MARITIMES NEAR DAYBREAK MONDAY...SO WESTERLY WIND GUSTS MAY REACH
20 TO 25 KNOTS NEAR 12Z MONDAY. OTHERWISE...RAIN AND SNOW THIS
EVENING AND TONIGHT WILL REDUCE VISIBILITIES AT TIMES FOR
MARINERS.

MONDAY...AS THE LOW PRESSURE GOING INTO THE CANADIAN MARITIMES
INTENSIFIES...INCREASING NORTHWEST WINDS ARE EXPECTED OVER THE
SOUTHERN NEW ENGLAND COASTAL WATERS...WITH GALE FORCE GUSTS
EXPECTED. GALE WARNINGS HAVE BEEN HOISTED FOR ALL COASTAL WATERS
FROM MIDDAY MONDAY INTO MONDAY NIGHT.

OUTLOOK...TUESDAY THROUGH FRIDAY..MODERATE CONFIDENCE.

TUESDAY... LINGERING 5 FOOT SEAS SOUTH AND EAST OF NANTUCKET IN THE
MORNING BUT DIMINISHING. NORTHWEST WINDS DIMINISHING FROM 20 KNOTS.
ANY SMALL CRAFT ADVISORY SHOULD END IN THE MORNING.

TUESDAY NIGHT-WEDNESDAY...SOUTH TO SOUTHWEST WINDS WILL INCREASE TO
20-25 KNOTS. SEAS WILL BUILD 6 TO 10 FEET ON THE OUTER WATERS AND ON
RI SOUND. REDUCED VSBYS...INITIALLY SNOW BUT CHANGING TO RAIN. A
SMALL CRAFT ADVISORY MAY BE NEEDED.

THURSDAY...NORTHWEST WIND GUSTING TO 25 KNOTS. SEAS 5 TO 8 FEET
MAINLY ON THE OUTER WATERS...DIMINISHING LATE. A SMALL CRAFT
ADVISORY MAY BE NEEDED.

FRIDAY... SHIFTING WINDS LESS THAN 20 KNOTS. SEAS LESS THAN 5 FEET.
QUIET WEATHER.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WINTER WEATHER ADVISORY UNTIL 4 AM EST EARLY THIS MORNING FOR
     CTZ002>004.
MA...WINTER STORM WARNING UNTIL 4 AM EST EARLY THIS MORNING FOR
     MAZ017>021.
     WINTER WEATHER ADVISORY UNTIL 4 AM EST EARLY THIS MORNING FOR
     MAZ002>016-022-023-026.
RI...WINTER STORM WARNING UNTIL 4 AM EST EARLY THIS MORNING FOR
     RIZ002>008.
     WINTER WEATHER ADVISORY UNTIL 4 AM EST EARLY THIS MORNING FOR
     RIZ001.
MARINE...GALE WARNING FROM 11 AM THIS MORNING TO 4 AM EST TUESDAY FOR
     ANZ231-232-250-251-254-255.
     GALE WARNING FROM 11 AM THIS MORNING TO 11 PM EST THIS EVENING
     FOR ANZ233>235-237-256.
     GALE WARNING FROM 11 AM THIS MORNING TO 8 PM EST THIS EVENING
     FOR ANZ230-236.

&&

$$
SYNOPSIS...WTB/NMB
NEAR TERM...FRANK
SHORT TERM...NMB
LONG TERM...WTB
AVIATION...FRANK/WTB
MARINE...WTB/NMB



000
FXUS61 KBOX 020601
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
100 AM EST MON MAR 2 2015

.SYNOPSIS...

DRY AND BLUSTERY WEATHER TODAY BEHIND A COLD FRONT. LOW PRESSURE
FROM NORTHERN CANADA AND ASSOCIATED LOW FORMING OVER THE PLAINS
MONDAY WILL MERGE...THEN PASS WEST AND NORTH OF NEW ENGLAND. THIS
WILL SWING A COLD FRONT ACROSS THE REGION ON WEDNESDAY. DRY AND COLD
WEATHER RETURNS FOR THE END OF THE WEEK. ANOTHER COLD FRONT MOVES
THROUGH ON SATURDAY.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...

1 AM UPDATE...

LAST GASP OF SNOW ACROSS RHODE ISLAND AND EASTERN MA WILL BE QUICKLY
EXITING THE REGION IN THE NEXT HOUR.  PTYPE HAS CHANGED TO
RAIN ACROSS THE CAPE/ISLANDS AND THAT WILL ALSO BE ENDING SHORTLY.
WE SHOULD BE ABLE TO TAKE DOWN ALL THE WINTER WEATHER HEADLINES
VERY SHORTLY.

OTHERWISE...AN ABUNDANCE OF MID LEVEL CLOUDINESS WILL HANG TOUGH
OVERNIGHT.  A COLD FRONT WILL CROSS THE REGION TOWARD MORNING...BUT
THE WINDS WILL NOT PICKUP TOO MUCH UNTIL AFTER SUNRISE.  LOW TEMPS
WILL GENERALLY REMAIN IN THE 20S WITH A LOT OF CLOUDS PERSISTING.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM TUESDAY/...
MONDAY...
PRECIPITATION WILL HAVE LARGELY COME TO AN END FOR DAYBREAK MONDAY
WITH THE LOW PRESSURE RAPIDLY PULLING AWAY INTO THE CANADIAN
MARITIMES AND DRIER AIR/HIGH PRESSURE MOVING IN FROM THE WEST.
INCREASING SUNSHINE EXPECTED DURING THE DAY...WITH TEMPS TOPPING
OUT IN THE UPPER 20S TO MID 30S. HOWEVER AS WE GET TOWARDS
MIDDAY/AFTERNOON TIGHTENING GRADIENT WILL ALLOW NORTHWEST FLOW TO
BECOME BLUSTERY...WITH GUSTS OF 25 TO 30 MPH...25 TO 35 MPH ON THE
CAPE AND ISLANDS.

MONDAY NIGHT...
HIGH PRESSURE SETTLES OVER THE AREA WITH CLEAR SKIES EXPECTED.
GIVEN OUR SNOWPACK IN PLACE AND LIGHT WINDS...SHOULD BE ANOTHER
NIGHT FOR EXCELLENT RADIATIONAL COOLING. BECAUSE OF THIS DID
GENERALLY GO BELOW MODEL GUIDANCE FOR MIN TEMPS...LOOKING TO
ANTICIPATED SURFACE DEWPOINTS FOR A GUIDELINE ON HOW LOW WE CAN
GO. MAY SEE SOME SPOTS IN THE INTERIOR DROP BELOW ZERO.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
BIG PICTURE... THE BROAD UPPER FLOW CONTINUES TO FEATURE A TROUGH
TRANSITING EAST ACROSS THE COUNTRY...REACHING THE EASTERN USA DURING
THE LATE WEEK AND LINGERING THROUGH THE WEEKEND. MEANWHILE AN UPPER
RIDGE SHIFTS FROM THE PACIFIC OCEAN BACK ASHORE ONTO THE WEST COAST.
CONTOUR HEIGHTS IN THE TROUGH ARE LOWEST THURSDAY-FRIDAY AND NEAR
NORMAL OVER THE WEEKEND. THIS MEANS A TREND TO COLDER TEMPS THURSDAY-
FRIDAY FOLLOWED BY A TREND CLOSER TO NORMAL OVER THE WEEKEND.

DAILIES...

TUESDAY... HIGH PRESSURE OVER THE REGION MOVES OFFSHORE BY AFTERNOON
WITH AIRFLOW SWINGING FROM NORTHWEST TO SOUTHWEST. THE SURFACE
AIRMASS STARTS OUT QUITE DRY WITH DEW POINTS IN THE SINGLE NUMBERS
BELOW ZERO TO START...CLIMBING TO 5-10 ABOVE BY EVENING. MODEL CROSS
SECTIONS SHOW INCREASING MOISTURE MORNING AND AFTERNOON ABOVE 700
MB. THIS SUGGESTS INCREASING MID AND HIGH CLOUDS WHILE DRY BENEATH.
LOW LEVEL JETS FROM THE CAROLINAS AND MIDWEST AND THE SURFACE
PRESSURE GRADIENT ALL SUGGEST THE INFLOW AND ISENTROPIC LIFT WILL
REMAIN TO OUR WEST THROUGH THE DAY...POSSIBLY ENTERING WESTERN MA/CT
AT OR AFTER 21Z. SO WE EXPECT INCREASING CLOUDS TUESDAY BUT
OTHERWISE DRY WEATHER THROUGH THE DAY. POSSIBLE LIGHT SNOW AROUND
THE EVENING RUSH HOUR IN THE CT RIVER VALLEY. TEMPS SHOULD REACH THE
MID 20S TO AROUND 30.

TUESDAY NIGHT-WEDNESDAY... NORTHERN AND SOUTHERN STREAM SHORTWAVES
MERGE OVER THE GREAT LAKES AND TRACK INTO CANADA. THIS BRINGS A MILD
FLOW OF AIR UP OVER NEW ENGLAND. THE LEADING EDGE OF THIS AIR
REACHES WESTERN SECTIONS TUESDAY EVENING AND EASTERN SECTIONS
TUESDAY NIGHT. TEMPERATURE PROFILES SUPPORT AN INITIAL PERIOD OF
SNOW CHANGING TO RAIN OR FREEZING RAIN OVERNIGHT. ACTUALLY...THE
MODELS MAY NOT BE HANDLING WELL THE CHILLING MASS OF SNOW AND COLD
GROUND /A.K.A. THE GIANT ICECUBE/ WHICH WOULD MEAN THE ACTUAL MAX
SFC TEMPS WILL BE COOLER THAN MODEL FORECASTS. TEMPERATURES AT 925
AND 950 MB WILL BE IN THE 30S...SO EXPECT SURFACE TEMPS NO HIGHER
THAN THE LOWER 40S.

THE SURFACE LOW PRESSURE AREA PASSES WELL NORTH OF NEW ENGLAND
WEDNESDAY AND SWINGS A COLD FRONT THROUGH THE REGION DURING THE
AFTERNOON OR EVENING. MOISTURE CROSS SECTIONS SHOW DECREASING RH IN
THE LIFT AND NUCLEATION ZONES ALOFT WEDNESDAY MORNING...SO THE TREND
THROUGH THE DAY SHOULD BE TO DIMINISHING POPS.

THURSDAY-FRIDAY... THE WEDNESDAY COLD FRONT WILL ALIGN WITH THE
UPPER FLOW AS IT MOVES SOUTH OF NEW ENGLAND...SLOWING ITS OFFSHORE
PROGRESS TO A CRAWL. MEANWHILE WE WILL BE UNDER THE RIGHT ENTRANCE
REGION OF THE SUPPORTING UPPER JET...A SOURCE OF UPPER VENTING. THIS
SHOULD SUPPORT LINGERING CLOUDS AND A CHANCE OF PCPN...WITH TEMPS
SUPPORTIVE OF SNOW. BEST CHANCE SOUTH COAST...LESSER CHANCE FARTHER
NORTH. THE JET AND SURFACE FRONT SWEEP OFFSHORE THURSDAY NIGHT. HIGH
PRESSURE THEN MOVES OVER THE EASTERN USA FOR FRIDAY. TEMPS ALOFT
SUPPORT MAX SFC TEMPS IN THE 20S.

SATURDAY-SUNDAY... ANOTHER NORTHERN STREAM SHORTWAVE AND COLD FRONT
SWINGS THROUGH THE FLOW SATURDAY. CROSS SECTIONS SHOW SOME MOISTURE
ALOFT BUT MOST OF IT IS CONCENTRATED TO OUR NORTH.  ALSO JUST
LIMITED LIFT TO WORK ON THAT MOISTURE. WE WILL HAVE 25-50 PCT SKY
COVER AND NIL POPS. HIGH PRESSURE THEN BUILDS FOR SUNDAY.

&&

.AVIATION /06Z MONDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TODAY THROUGH TUESDAY/...

TODAY...HIGH CONFIDENCE.  LEFT OVER MVFR-IFR CONDITIONS IN LIGHT
SNOW SHOULD IMPROVE TO VFR BY 7 OR 8Z.  OTHERWISE...EXPECT VFR
CONDITIONS DESPITE A SCATTERED TO EVEN BROKEN DECK OF STRATO-CUMULUS
CLOUDS.  WEST TO NORTHWEST WIND GUSTS OF 25 TO 35 ARE EXPECTED TO
DEVELOP LATER THIS MORNING AND CONTINUE INTO THE AFTERNOON.

TONIGHT...HIGH CONFIDENCE.  WINDS GRADUALLY DIMINISH THIS EVENING
WITH VFR CONDITIONS CONTINUING.

TUESDAY...MODERATE TO HIGH CONFIDENCE.  VFR CONDITIONS
THROUGH AT LEAST MID AFTERNOON.  MVFR-IFR CONDITIONS MAY DEVELOP BY
LATE TUE AFTERNOON/EARLY EVENING ACROSS WESTERN MA/NORTHERN CT AS
SNOW OVERSPREADS THE REGION.

KBOS TAF...HIGH CONFIDENCE.  NORTHWEST WIND GUSTS OF 25 TO 35 KNOTS
LATER THIS MORNING AND AFTERNOON.

KBDL TAF...HIGH CONFIDENCE.  NORTHWEST WIND GUSTS OF 25 TO 35 KNOTS
LATER THIS MORNING AND AFTERNOON.

OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY...

TUESDAY NIGHT-WEDNESDAY...MODERATE CONFIDENCE. CONDITIONS LOWERING
TO IFR/LIFR. INITIALLY SNOW BUT CHANGING TO SLEET/FREEZING RAIN
DURING THE NIGHT AND RAIN IN THE COASTAL PLAIN OVERNIGHT. PCPN
CHANGES TO RAIN ALL AREAS WEDNESDAY...BUT COLD SURFACES COULD
MAINTAIN A FREEZING RAIN ELEMENT WEDNESDAY MORNING. COLDER AIR MOVES
IN WEDNESDAY NIGHT CHANGING ANY RAIN TO SNOW.

THURSDAY...LOW CONFIDENCE. VFR NORTH OF A HFD-BOS LINE. MVFR CIGS
AND AREAS OF MVFR/IFR VSBYS IN SNOW...DIMINISHING BY EVENING.
NORTHWEST WINDS GUSTING TO 20 KNOTS.

FRIDAY...MODERATE CONFIDENCE. VFR.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...HIGH CONFIDENCE.

A WEAK WAVE OF LOW PRESSURE MOVES ACROSS THE WATERS TONIGHT.
THIS SYSTEM REALLY INTENSIFIES AS IT MOVES INTO THE CANADIAN
MARITIMES NEAR DAYBREAK MONDAY...SO WESTERLY WIND GUSTS MAY REACH
20 TO 25 KNOTS NEAR 12Z MONDAY. OTHERWISE...RAIN AND SNOW THIS
EVENING AND TONIGHT WILL REDUCE VISIBILITIES AT TIMES FOR
MARINERS.

MONDAY...AS THE LOW PRESSURE GOING INTO THE CANADIAN MARITIMES
INTENSIFIES...INCREASING NORTHWEST WINDS ARE EXPECTED OVER THE
SOUTHERN NEW ENGLAND COASTAL WATERS...WITH GALE FORCE GUSTS
EXPECTED. GALE WARNINGS HAVE BEEN HOISTED FOR ALL COASTAL WATERS
FROM MIDDAY MONDAY INTO MONDAY NIGHT.

OUTLOOK...TUESDAY THROUGH FRIDAY..MODERATE CONFIDENCE.

TUESDAY... LINGERING 5 FOOT SEAS SOUTH AND EAST OF NANTUCKET IN THE
MORNING BUT DIMINISHING. NORTHWEST WINDS DIMINISHING FROM 20 KNOTS.
ANY SMALL CRAFT ADVISORY SHOULD END IN THE MORNING.

TUESDAY NIGHT-WEDNESDAY...SOUTH TO SOUTHWEST WINDS WILL INCREASE TO
20-25 KNOTS. SEAS WILL BUILD 6 TO 10 FEET ON THE OUTER WATERS AND ON
RI SOUND. REDUCED VSBYS...INITIALLY SNOW BUT CHANGING TO RAIN. A
SMALL CRAFT ADVISORY MAY BE NEEDED.

THURSDAY...NORTHWEST WIND GUSTING TO 25 KNOTS. SEAS 5 TO 8 FEET
MAINLY ON THE OUTER WATERS...DIMINISHING LATE. A SMALL CRAFT
ADVISORY MAY BE NEEDED.

FRIDAY... SHIFTING WINDS LESS THAN 20 KNOTS. SEAS LESS THAN 5 FEET.
QUIET WEATHER.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WINTER WEATHER ADVISORY UNTIL 4 AM EST EARLY THIS MORNING FOR
     CTZ002>004.
MA...WINTER STORM WARNING UNTIL 4 AM EST EARLY THIS MORNING FOR
     MAZ017>021.
     WINTER WEATHER ADVISORY UNTIL 4 AM EST EARLY THIS MORNING FOR
     MAZ002>016-022-023-026.
RI...WINTER STORM WARNING UNTIL 4 AM EST EARLY THIS MORNING FOR
     RIZ002>008.
     WINTER WEATHER ADVISORY UNTIL 4 AM EST EARLY THIS MORNING FOR
     RIZ001.
MARINE...GALE WARNING FROM 11 AM THIS MORNING TO 4 AM EST TUESDAY FOR
     ANZ231-232-250-251-254-255.
     GALE WARNING FROM 11 AM THIS MORNING TO 11 PM EST THIS EVENING
     FOR ANZ233>235-237-256.
     GALE WARNING FROM 11 AM THIS MORNING TO 8 PM EST THIS EVENING
     FOR ANZ230-236.

&&

$$
SYNOPSIS...WTB/NMB
NEAR TERM...FRANK
SHORT TERM...NMB
LONG TERM...WTB
AVIATION...FRANK/WTB
MARINE...WTB/NMB




000
FXUS61 KBOX 020601
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
100 AM EST MON MAR 2 2015

.SYNOPSIS...

DRY AND BLUSTERY WEATHER TODAY BEHIND A COLD FRONT. LOW PRESSURE
FROM NORTHERN CANADA AND ASSOCIATED LOW FORMING OVER THE PLAINS
MONDAY WILL MERGE...THEN PASS WEST AND NORTH OF NEW ENGLAND. THIS
WILL SWING A COLD FRONT ACROSS THE REGION ON WEDNESDAY. DRY AND COLD
WEATHER RETURNS FOR THE END OF THE WEEK. ANOTHER COLD FRONT MOVES
THROUGH ON SATURDAY.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...

1 AM UPDATE...

LAST GASP OF SNOW ACROSS RHODE ISLAND AND EASTERN MA WILL BE QUICKLY
EXITING THE REGION IN THE NEXT HOUR.  PTYPE HAS CHANGED TO
RAIN ACROSS THE CAPE/ISLANDS AND THAT WILL ALSO BE ENDING SHORTLY.
WE SHOULD BE ABLE TO TAKE DOWN ALL THE WINTER WEATHER HEADLINES
VERY SHORTLY.

OTHERWISE...AN ABUNDANCE OF MID LEVEL CLOUDINESS WILL HANG TOUGH
OVERNIGHT.  A COLD FRONT WILL CROSS THE REGION TOWARD MORNING...BUT
THE WINDS WILL NOT PICKUP TOO MUCH UNTIL AFTER SUNRISE.  LOW TEMPS
WILL GENERALLY REMAIN IN THE 20S WITH A LOT OF CLOUDS PERSISTING.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM TUESDAY/...
MONDAY...
PRECIPITATION WILL HAVE LARGELY COME TO AN END FOR DAYBREAK MONDAY
WITH THE LOW PRESSURE RAPIDLY PULLING AWAY INTO THE CANADIAN
MARITIMES AND DRIER AIR/HIGH PRESSURE MOVING IN FROM THE WEST.
INCREASING SUNSHINE EXPECTED DURING THE DAY...WITH TEMPS TOPPING
OUT IN THE UPPER 20S TO MID 30S. HOWEVER AS WE GET TOWARDS
MIDDAY/AFTERNOON TIGHTENING GRADIENT WILL ALLOW NORTHWEST FLOW TO
BECOME BLUSTERY...WITH GUSTS OF 25 TO 30 MPH...25 TO 35 MPH ON THE
CAPE AND ISLANDS.

MONDAY NIGHT...
HIGH PRESSURE SETTLES OVER THE AREA WITH CLEAR SKIES EXPECTED.
GIVEN OUR SNOWPACK IN PLACE AND LIGHT WINDS...SHOULD BE ANOTHER
NIGHT FOR EXCELLENT RADIATIONAL COOLING. BECAUSE OF THIS DID
GENERALLY GO BELOW MODEL GUIDANCE FOR MIN TEMPS...LOOKING TO
ANTICIPATED SURFACE DEWPOINTS FOR A GUIDELINE ON HOW LOW WE CAN
GO. MAY SEE SOME SPOTS IN THE INTERIOR DROP BELOW ZERO.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
BIG PICTURE... THE BROAD UPPER FLOW CONTINUES TO FEATURE A TROUGH
TRANSITING EAST ACROSS THE COUNTRY...REACHING THE EASTERN USA DURING
THE LATE WEEK AND LINGERING THROUGH THE WEEKEND. MEANWHILE AN UPPER
RIDGE SHIFTS FROM THE PACIFIC OCEAN BACK ASHORE ONTO THE WEST COAST.
CONTOUR HEIGHTS IN THE TROUGH ARE LOWEST THURSDAY-FRIDAY AND NEAR
NORMAL OVER THE WEEKEND. THIS MEANS A TREND TO COLDER TEMPS THURSDAY-
FRIDAY FOLLOWED BY A TREND CLOSER TO NORMAL OVER THE WEEKEND.

DAILIES...

TUESDAY... HIGH PRESSURE OVER THE REGION MOVES OFFSHORE BY AFTERNOON
WITH AIRFLOW SWINGING FROM NORTHWEST TO SOUTHWEST. THE SURFACE
AIRMASS STARTS OUT QUITE DRY WITH DEW POINTS IN THE SINGLE NUMBERS
BELOW ZERO TO START...CLIMBING TO 5-10 ABOVE BY EVENING. MODEL CROSS
SECTIONS SHOW INCREASING MOISTURE MORNING AND AFTERNOON ABOVE 700
MB. THIS SUGGESTS INCREASING MID AND HIGH CLOUDS WHILE DRY BENEATH.
LOW LEVEL JETS FROM THE CAROLINAS AND MIDWEST AND THE SURFACE
PRESSURE GRADIENT ALL SUGGEST THE INFLOW AND ISENTROPIC LIFT WILL
REMAIN TO OUR WEST THROUGH THE DAY...POSSIBLY ENTERING WESTERN MA/CT
AT OR AFTER 21Z. SO WE EXPECT INCREASING CLOUDS TUESDAY BUT
OTHERWISE DRY WEATHER THROUGH THE DAY. POSSIBLE LIGHT SNOW AROUND
THE EVENING RUSH HOUR IN THE CT RIVER VALLEY. TEMPS SHOULD REACH THE
MID 20S TO AROUND 30.

TUESDAY NIGHT-WEDNESDAY... NORTHERN AND SOUTHERN STREAM SHORTWAVES
MERGE OVER THE GREAT LAKES AND TRACK INTO CANADA. THIS BRINGS A MILD
FLOW OF AIR UP OVER NEW ENGLAND. THE LEADING EDGE OF THIS AIR
REACHES WESTERN SECTIONS TUESDAY EVENING AND EASTERN SECTIONS
TUESDAY NIGHT. TEMPERATURE PROFILES SUPPORT AN INITIAL PERIOD OF
SNOW CHANGING TO RAIN OR FREEZING RAIN OVERNIGHT. ACTUALLY...THE
MODELS MAY NOT BE HANDLING WELL THE CHILLING MASS OF SNOW AND COLD
GROUND /A.K.A. THE GIANT ICECUBE/ WHICH WOULD MEAN THE ACTUAL MAX
SFC TEMPS WILL BE COOLER THAN MODEL FORECASTS. TEMPERATURES AT 925
AND 950 MB WILL BE IN THE 30S...SO EXPECT SURFACE TEMPS NO HIGHER
THAN THE LOWER 40S.

THE SURFACE LOW PRESSURE AREA PASSES WELL NORTH OF NEW ENGLAND
WEDNESDAY AND SWINGS A COLD FRONT THROUGH THE REGION DURING THE
AFTERNOON OR EVENING. MOISTURE CROSS SECTIONS SHOW DECREASING RH IN
THE LIFT AND NUCLEATION ZONES ALOFT WEDNESDAY MORNING...SO THE TREND
THROUGH THE DAY SHOULD BE TO DIMINISHING POPS.

THURSDAY-FRIDAY... THE WEDNESDAY COLD FRONT WILL ALIGN WITH THE
UPPER FLOW AS IT MOVES SOUTH OF NEW ENGLAND...SLOWING ITS OFFSHORE
PROGRESS TO A CRAWL. MEANWHILE WE WILL BE UNDER THE RIGHT ENTRANCE
REGION OF THE SUPPORTING UPPER JET...A SOURCE OF UPPER VENTING. THIS
SHOULD SUPPORT LINGERING CLOUDS AND A CHANCE OF PCPN...WITH TEMPS
SUPPORTIVE OF SNOW. BEST CHANCE SOUTH COAST...LESSER CHANCE FARTHER
NORTH. THE JET AND SURFACE FRONT SWEEP OFFSHORE THURSDAY NIGHT. HIGH
PRESSURE THEN MOVES OVER THE EASTERN USA FOR FRIDAY. TEMPS ALOFT
SUPPORT MAX SFC TEMPS IN THE 20S.

SATURDAY-SUNDAY... ANOTHER NORTHERN STREAM SHORTWAVE AND COLD FRONT
SWINGS THROUGH THE FLOW SATURDAY. CROSS SECTIONS SHOW SOME MOISTURE
ALOFT BUT MOST OF IT IS CONCENTRATED TO OUR NORTH.  ALSO JUST
LIMITED LIFT TO WORK ON THAT MOISTURE. WE WILL HAVE 25-50 PCT SKY
COVER AND NIL POPS. HIGH PRESSURE THEN BUILDS FOR SUNDAY.

&&

.AVIATION /06Z MONDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TODAY THROUGH TUESDAY/...

TODAY...HIGH CONFIDENCE.  LEFT OVER MVFR-IFR CONDITIONS IN LIGHT
SNOW SHOULD IMPROVE TO VFR BY 7 OR 8Z.  OTHERWISE...EXPECT VFR
CONDITIONS DESPITE A SCATTERED TO EVEN BROKEN DECK OF STRATO-CUMULUS
CLOUDS.  WEST TO NORTHWEST WIND GUSTS OF 25 TO 35 ARE EXPECTED TO
DEVELOP LATER THIS MORNING AND CONTINUE INTO THE AFTERNOON.

TONIGHT...HIGH CONFIDENCE.  WINDS GRADUALLY DIMINISH THIS EVENING
WITH VFR CONDITIONS CONTINUING.

TUESDAY...MODERATE TO HIGH CONFIDENCE.  VFR CONDITIONS
THROUGH AT LEAST MID AFTERNOON.  MVFR-IFR CONDITIONS MAY DEVELOP BY
LATE TUE AFTERNOON/EARLY EVENING ACROSS WESTERN MA/NORTHERN CT AS
SNOW OVERSPREADS THE REGION.

KBOS TAF...HIGH CONFIDENCE.  NORTHWEST WIND GUSTS OF 25 TO 35 KNOTS
LATER THIS MORNING AND AFTERNOON.

KBDL TAF...HIGH CONFIDENCE.  NORTHWEST WIND GUSTS OF 25 TO 35 KNOTS
LATER THIS MORNING AND AFTERNOON.

OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY...

TUESDAY NIGHT-WEDNESDAY...MODERATE CONFIDENCE. CONDITIONS LOWERING
TO IFR/LIFR. INITIALLY SNOW BUT CHANGING TO SLEET/FREEZING RAIN
DURING THE NIGHT AND RAIN IN THE COASTAL PLAIN OVERNIGHT. PCPN
CHANGES TO RAIN ALL AREAS WEDNESDAY...BUT COLD SURFACES COULD
MAINTAIN A FREEZING RAIN ELEMENT WEDNESDAY MORNING. COLDER AIR MOVES
IN WEDNESDAY NIGHT CHANGING ANY RAIN TO SNOW.

THURSDAY...LOW CONFIDENCE. VFR NORTH OF A HFD-BOS LINE. MVFR CIGS
AND AREAS OF MVFR/IFR VSBYS IN SNOW...DIMINISHING BY EVENING.
NORTHWEST WINDS GUSTING TO 20 KNOTS.

FRIDAY...MODERATE CONFIDENCE. VFR.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...HIGH CONFIDENCE.

A WEAK WAVE OF LOW PRESSURE MOVES ACROSS THE WATERS TONIGHT.
THIS SYSTEM REALLY INTENSIFIES AS IT MOVES INTO THE CANADIAN
MARITIMES NEAR DAYBREAK MONDAY...SO WESTERLY WIND GUSTS MAY REACH
20 TO 25 KNOTS NEAR 12Z MONDAY. OTHERWISE...RAIN AND SNOW THIS
EVENING AND TONIGHT WILL REDUCE VISIBILITIES AT TIMES FOR
MARINERS.

MONDAY...AS THE LOW PRESSURE GOING INTO THE CANADIAN MARITIMES
INTENSIFIES...INCREASING NORTHWEST WINDS ARE EXPECTED OVER THE
SOUTHERN NEW ENGLAND COASTAL WATERS...WITH GALE FORCE GUSTS
EXPECTED. GALE WARNINGS HAVE BEEN HOISTED FOR ALL COASTAL WATERS
FROM MIDDAY MONDAY INTO MONDAY NIGHT.

OUTLOOK...TUESDAY THROUGH FRIDAY..MODERATE CONFIDENCE.

TUESDAY... LINGERING 5 FOOT SEAS SOUTH AND EAST OF NANTUCKET IN THE
MORNING BUT DIMINISHING. NORTHWEST WINDS DIMINISHING FROM 20 KNOTS.
ANY SMALL CRAFT ADVISORY SHOULD END IN THE MORNING.

TUESDAY NIGHT-WEDNESDAY...SOUTH TO SOUTHWEST WINDS WILL INCREASE TO
20-25 KNOTS. SEAS WILL BUILD 6 TO 10 FEET ON THE OUTER WATERS AND ON
RI SOUND. REDUCED VSBYS...INITIALLY SNOW BUT CHANGING TO RAIN. A
SMALL CRAFT ADVISORY MAY BE NEEDED.

THURSDAY...NORTHWEST WIND GUSTING TO 25 KNOTS. SEAS 5 TO 8 FEET
MAINLY ON THE OUTER WATERS...DIMINISHING LATE. A SMALL CRAFT
ADVISORY MAY BE NEEDED.

FRIDAY... SHIFTING WINDS LESS THAN 20 KNOTS. SEAS LESS THAN 5 FEET.
QUIET WEATHER.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WINTER WEATHER ADVISORY UNTIL 4 AM EST EARLY THIS MORNING FOR
     CTZ002>004.
MA...WINTER STORM WARNING UNTIL 4 AM EST EARLY THIS MORNING FOR
     MAZ017>021.
     WINTER WEATHER ADVISORY UNTIL 4 AM EST EARLY THIS MORNING FOR
     MAZ002>016-022-023-026.
RI...WINTER STORM WARNING UNTIL 4 AM EST EARLY THIS MORNING FOR
     RIZ002>008.
     WINTER WEATHER ADVISORY UNTIL 4 AM EST EARLY THIS MORNING FOR
     RIZ001.
MARINE...GALE WARNING FROM 11 AM THIS MORNING TO 4 AM EST TUESDAY FOR
     ANZ231-232-250-251-254-255.
     GALE WARNING FROM 11 AM THIS MORNING TO 11 PM EST THIS EVENING
     FOR ANZ233>235-237-256.
     GALE WARNING FROM 11 AM THIS MORNING TO 8 PM EST THIS EVENING
     FOR ANZ230-236.

&&

$$
SYNOPSIS...WTB/NMB
NEAR TERM...FRANK
SHORT TERM...NMB
LONG TERM...WTB
AVIATION...FRANK/WTB
MARINE...WTB/NMB




000
FXUS61 KGYX 020453
AFDGYX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
1153 PM EST SUN MAR 1 2015

.SYNOPSIS...
LOW PRESSURE WILL MOVE EAST AND CROSS THE REGION OVERNIGHT...PRODUCING
SOME LIGHT SNOW. A STRONG NORTHWEST FLOW WILL SET UP IN ITS WAKE
ON MONDAY. HIGH PRESSURE WILL BUILD IN FROM THE WEST MONDAY NIGHT
AND WILL CREST OVER THE REGION EARLY TUESDAY BEFORE MOVING
OFFSHORE. LOW PRESSURE WILL SWING THROUGH SOUTHERN CANADA TUESDAY
NIGHT PUSHING A WARM FRONT NORTH ACROSS THE REGION...AND PRODUCING
A PERIOD OF SNOW AND MIXED RAIN OR SNOW ALONG THE COAST. AS THE
LOW SHIFTS TO OUR NORTH...IT WILL DRAG A COLD FRONT THROUGH THE
REGION LATE WEDNESDAY. HIGH PRESSURE WILL BUILD IN FROM THE WEST
THURSDAY AND WILL CREST OVER THE REGION ON FRIDAY.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
1150 PM...HAVE BACKED OFF SNOW ANTS SLIGHTLY ONE MORE TIME...MORE
SO IN THE N WHERE THEY LOOK TO AN INCH. WITH SOME AMTS NEAR 3
INCHES IN SRN NH AND THE THE ME COAST.  STARTING TO SEE DRIER AIR
WORK IN FROM THE NW...CUTTING INTO THE RADAR ECHOES THERE...AND A
DIFFUSE BACK EDGE IN SW NH. A FEW REPORTS FROM SW NH AND YORK
COUNTY ME WITH NEAR 2 INCHES. ECHOES STILL FLARING A BIT EAST OF
CASCO BAY...AND THIS IS WHERE ACCUMS ARE THE BEST BET FOR A FEW
MORE HOURS. SPOTTY LIGHT SNOW LKLY TO CONTINUE TO ABOUT 06-08Z
ELSEWHERE...LITTLE IF ANY ADDL ACCUM IS EXPECTED....AND IT SHOULD
MOVE OUT OF THE MID-COAST BY 09-10Z.

930PM UPDATE...
SNOW IS PROGRESSING ACROSS THE FORECAST AREA THIS EVENING WITH THE
BACK EDGE ALREADY APPEARING IN WESTERN MASSACHUSETTS AND EASTERN
NEW YORK STATE. FEW REPORTS RECEIVED SO FAR HAVE ALL BEEN UNDER 1
INCH. EXPECT STORM TOTALS TO STRUGGLE TO REACH 3 INCHES ALTHOUGH
SOME ENHANCEMENT INLAND OF THE MIDCOAST HAS BEEN NOTED. NO
SIGNIFICANT CHANGES HAVE BEEN MADE TO THE FORECAST.

5PM UPDATE...
HAVE UPDATED PRECIPITATION CHANCES AND SNOWFALL FORECAST OVERNIGHT
AS MORE INTENSE ECHOES NOW SHOWING UP ON RADAR. BEST CHANCE AT
SEEING AN INCH OR TWO WILL BE NEAR THE COAST AND OVER SOUTHERN NEW
HAMPSHIRE WHERE AS MUCH AS 3 INCHES IS POSSIBLE.

ORIGINAL DISCUSSION...
SNOW WILL CONTINUE TO SPREAD EAST THIS EVENING IN ASSOCIATION
WITH BROAD SCALE WARM AIR ADVECTION PATTERN. SOME OF THIS
PRECIPITATION HOWEVER WILL CONTINUE TO SUBLIMATE AS IT INTERACTS
WITH A VERY DRY ATMOSPHERE OVER MAINE AND NEW HAMPSHIRE. EXPECT
PERIODS OF LIGHT SNOW OVERNIGHT. 12Z MODEL SUITE AND MESOSCALE
MODELS HAVE CONTINUED TO BACK OFF ON THE PRECIPITATION FIELDS AND
THEREFORE SNOWFALL AMOUNTS. NEVERTHELESS...THE HIGHEST TOTALS WILL
BE 3-4 INCHES ALONG PORTIONS OF THE MIDCOAST AND OVER FAR SOUTHERN
NH NEAR THE MASSACHUSETTS BORDER. THIS WILL BE JUST BELOW SNOW
ADVISORY CRITERIA.

IT WILL BE A MUCH MILDER NIGHT THAN THOSE OF THE LAST SEVERAL
NIGHTS WITH READINGS BETWEEN 15 AND 25 DEGREES FROM NORTH TO
SOUTH.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
UPPER LEVEL SUPPORT REMAINS DISJOINTED FROM THE SURFACE
REFLECTION ON MONDAY...WITH THE SHORT WAVE CROSSING LAKE ONTARIO
BY EARLY MONDAY MORNING. THERE COULD BE A PASSING SNOW SHOWER WITH
THIS FEATURE. ACROSS THE NORTHWEST FACING HIGHER TERRAIN...SOME
UPSLOPING PRECIPITATION MAY OCCUR.

AS ARCTIC HIGH BUILDS OVER THE REGION...TEMPERATURES WILL ONCE
AGAIN DROP BELOW ZERO IN NORTHERN AREAS. WIND CHILL VALUES WILL BE
HEADING DOWNWARDS AGAIN AS WELL...BRIEFLY APPROACHING WIND CHILL
ADVISORY LEVELS IN THE MOUNTAINS.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
A SUNNY START ON TUESDAY AS HIGH PRESSURE IS CENTERED OVER THE
REGION. INCREASING HIGH CLOUDS WILL SPILL OVER THE SURFACE/UPPER
RIDGE IN THE AFTERNOON AS THE RIDGE AXIS MOVES OFF TO THE EAST.
TUESDAY NIGHT THE SOUTHWEST FLOW ALOFT WILL ALLOW A SHORT WAVE AND
ASSOCIATED WARM FRONT TO MOVE NORTH INTO NORTHERN NEW ENGLAND WITH
WIDESPREAD WARM AIR ADVECTION SNOW EXPECTED. MID/LOW LEVEL
TEMPERATURES SHOULD ALL BE COLD ENOUGH FOR SNOW EXCEPT ALONG THE
IMMEDIATE COAST WHERE A BRIEF MIX WITH RAIN MAY OCCUR BEFORE
ENDING EARLY WEDNESDAY MORNING. A BLEND OF MODELS QPF SUGGESTS A
SNOWFALL OF 2-6 INCHES EXPECTED. ON WEDNESDAY ALL MODELS INDICATE
THE SNOW TO BE OVER BY EARLY MORNING AND THEN SOME CLEARING AND
TEMPERATURES REACHING INTO THE 40S OVER MOST OF THE AREA AS H85
TEMPERATURES REMAIN MILD INTO THE AFTERNOON COMBINED WITH A
DEVELOPING LIGHT DOWNSLOPING WEST WIND. COLD AIR RETURNS FOR
WEDNESDAY NIGHT AND THURSDAY AS HIGH PRESSURE FROM THE GREAT LAKES
BUILDS EAST AND CONTINUES INTO FRIDAY. TEMPERATURES WILL RETURN TO
BELOW NORMAL FOR THURSDAY AND FRIDAY LIKE A BROKEN RECORD.

&&

.AVIATION /06Z MONDAY THROUGH FRIDAY/...
SHORT TERM...CEILINGS AND VISIBILITIES GRADUALLY LOWERING AND
DIMINISHING THIS EVENING IN LIGHT SNOW. IFR CONDITIONS EXPECTED IN
MANY AREAS...ESPECIALLY OVER SOUTHERN LOCATIONS.

LONG TERM...
VFR TUESDAY BECOMING IFR TUESDAY NIGHT AND THEN A RETURN TO VFR
CONDITIONS FOR THE MID AND LATTER PART OF THE WEEK.

&&

.MARINE...
SHORT TERM...WILL BE ISSUING GALE WARNINGS FOR MONDAY AFTERNOON
THROUGH MONDAY EVENING FOR THE OUTER WATERS. WINDS WILL JUST TOUCH
GALE FORCE WELL AWAY FROM THE SHORELINE. ALONG THE BAYS...EXPECT
SMALL CRAFT ADVISORY TYPE WINDS INTO TOMORROW EVENING.

LONG TERM...
SCA`S MAY BE NEEDED IN THE SOUTH SOUTHWEST FLOW TUESDAY NIGHT.
THE SCA MAY ALSO BE NEEDED WEDNESDAY NIGHT AND THURSDAY WITH THE
NORTHWEST FLOW.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY FROM NOON TO 11 PM EST MONDAY FOR ANZ151-
     153.
     GALE WARNING FROM NOON TO 11 PM EST MONDAY FOR ANZ150-152-154.

&&

$$
SYNOPSIS...
NEAR TERM...CEMPA
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...



000
FXUS61 KGYX 020453
AFDGYX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
1153 PM EST SUN MAR 1 2015

.SYNOPSIS...
LOW PRESSURE WILL MOVE EAST AND CROSS THE REGION OVERNIGHT...PRODUCING
SOME LIGHT SNOW. A STRONG NORTHWEST FLOW WILL SET UP IN ITS WAKE
ON MONDAY. HIGH PRESSURE WILL BUILD IN FROM THE WEST MONDAY NIGHT
AND WILL CREST OVER THE REGION EARLY TUESDAY BEFORE MOVING
OFFSHORE. LOW PRESSURE WILL SWING THROUGH SOUTHERN CANADA TUESDAY
NIGHT PUSHING A WARM FRONT NORTH ACROSS THE REGION...AND PRODUCING
A PERIOD OF SNOW AND MIXED RAIN OR SNOW ALONG THE COAST. AS THE
LOW SHIFTS TO OUR NORTH...IT WILL DRAG A COLD FRONT THROUGH THE
REGION LATE WEDNESDAY. HIGH PRESSURE WILL BUILD IN FROM THE WEST
THURSDAY AND WILL CREST OVER THE REGION ON FRIDAY.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
1150 PM...HAVE BACKED OFF SNOW ANTS SLIGHTLY ONE MORE TIME...MORE
SO IN THE N WHERE THEY LOOK TO AN INCH. WITH SOME AMTS NEAR 3
INCHES IN SRN NH AND THE THE ME COAST.  STARTING TO SEE DRIER AIR
WORK IN FROM THE NW...CUTTING INTO THE RADAR ECHOES THERE...AND A
DIFFUSE BACK EDGE IN SW NH. A FEW REPORTS FROM SW NH AND YORK
COUNTY ME WITH NEAR 2 INCHES. ECHOES STILL FLARING A BIT EAST OF
CASCO BAY...AND THIS IS WHERE ACCUMS ARE THE BEST BET FOR A FEW
MORE HOURS. SPOTTY LIGHT SNOW LKLY TO CONTINUE TO ABOUT 06-08Z
ELSEWHERE...LITTLE IF ANY ADDL ACCUM IS EXPECTED....AND IT SHOULD
MOVE OUT OF THE MID-COAST BY 09-10Z.

930PM UPDATE...
SNOW IS PROGRESSING ACROSS THE FORECAST AREA THIS EVENING WITH THE
BACK EDGE ALREADY APPEARING IN WESTERN MASSACHUSETTS AND EASTERN
NEW YORK STATE. FEW REPORTS RECEIVED SO FAR HAVE ALL BEEN UNDER 1
INCH. EXPECT STORM TOTALS TO STRUGGLE TO REACH 3 INCHES ALTHOUGH
SOME ENHANCEMENT INLAND OF THE MIDCOAST HAS BEEN NOTED. NO
SIGNIFICANT CHANGES HAVE BEEN MADE TO THE FORECAST.

5PM UPDATE...
HAVE UPDATED PRECIPITATION CHANCES AND SNOWFALL FORECAST OVERNIGHT
AS MORE INTENSE ECHOES NOW SHOWING UP ON RADAR. BEST CHANCE AT
SEEING AN INCH OR TWO WILL BE NEAR THE COAST AND OVER SOUTHERN NEW
HAMPSHIRE WHERE AS MUCH AS 3 INCHES IS POSSIBLE.

ORIGINAL DISCUSSION...
SNOW WILL CONTINUE TO SPREAD EAST THIS EVENING IN ASSOCIATION
WITH BROAD SCALE WARM AIR ADVECTION PATTERN. SOME OF THIS
PRECIPITATION HOWEVER WILL CONTINUE TO SUBLIMATE AS IT INTERACTS
WITH A VERY DRY ATMOSPHERE OVER MAINE AND NEW HAMPSHIRE. EXPECT
PERIODS OF LIGHT SNOW OVERNIGHT. 12Z MODEL SUITE AND MESOSCALE
MODELS HAVE CONTINUED TO BACK OFF ON THE PRECIPITATION FIELDS AND
THEREFORE SNOWFALL AMOUNTS. NEVERTHELESS...THE HIGHEST TOTALS WILL
BE 3-4 INCHES ALONG PORTIONS OF THE MIDCOAST AND OVER FAR SOUTHERN
NH NEAR THE MASSACHUSETTS BORDER. THIS WILL BE JUST BELOW SNOW
ADVISORY CRITERIA.

IT WILL BE A MUCH MILDER NIGHT THAN THOSE OF THE LAST SEVERAL
NIGHTS WITH READINGS BETWEEN 15 AND 25 DEGREES FROM NORTH TO
SOUTH.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
UPPER LEVEL SUPPORT REMAINS DISJOINTED FROM THE SURFACE
REFLECTION ON MONDAY...WITH THE SHORT WAVE CROSSING LAKE ONTARIO
BY EARLY MONDAY MORNING. THERE COULD BE A PASSING SNOW SHOWER WITH
THIS FEATURE. ACROSS THE NORTHWEST FACING HIGHER TERRAIN...SOME
UPSLOPING PRECIPITATION MAY OCCUR.

AS ARCTIC HIGH BUILDS OVER THE REGION...TEMPERATURES WILL ONCE
AGAIN DROP BELOW ZERO IN NORTHERN AREAS. WIND CHILL VALUES WILL BE
HEADING DOWNWARDS AGAIN AS WELL...BRIEFLY APPROACHING WIND CHILL
ADVISORY LEVELS IN THE MOUNTAINS.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
A SUNNY START ON TUESDAY AS HIGH PRESSURE IS CENTERED OVER THE
REGION. INCREASING HIGH CLOUDS WILL SPILL OVER THE SURFACE/UPPER
RIDGE IN THE AFTERNOON AS THE RIDGE AXIS MOVES OFF TO THE EAST.
TUESDAY NIGHT THE SOUTHWEST FLOW ALOFT WILL ALLOW A SHORT WAVE AND
ASSOCIATED WARM FRONT TO MOVE NORTH INTO NORTHERN NEW ENGLAND WITH
WIDESPREAD WARM AIR ADVECTION SNOW EXPECTED. MID/LOW LEVEL
TEMPERATURES SHOULD ALL BE COLD ENOUGH FOR SNOW EXCEPT ALONG THE
IMMEDIATE COAST WHERE A BRIEF MIX WITH RAIN MAY OCCUR BEFORE
ENDING EARLY WEDNESDAY MORNING. A BLEND OF MODELS QPF SUGGESTS A
SNOWFALL OF 2-6 INCHES EXPECTED. ON WEDNESDAY ALL MODELS INDICATE
THE SNOW TO BE OVER BY EARLY MORNING AND THEN SOME CLEARING AND
TEMPERATURES REACHING INTO THE 40S OVER MOST OF THE AREA AS H85
TEMPERATURES REMAIN MILD INTO THE AFTERNOON COMBINED WITH A
DEVELOPING LIGHT DOWNSLOPING WEST WIND. COLD AIR RETURNS FOR
WEDNESDAY NIGHT AND THURSDAY AS HIGH PRESSURE FROM THE GREAT LAKES
BUILDS EAST AND CONTINUES INTO FRIDAY. TEMPERATURES WILL RETURN TO
BELOW NORMAL FOR THURSDAY AND FRIDAY LIKE A BROKEN RECORD.

&&

.AVIATION /06Z MONDAY THROUGH FRIDAY/...
SHORT TERM...CEILINGS AND VISIBILITIES GRADUALLY LOWERING AND
DIMINISHING THIS EVENING IN LIGHT SNOW. IFR CONDITIONS EXPECTED IN
MANY AREAS...ESPECIALLY OVER SOUTHERN LOCATIONS.

LONG TERM...
VFR TUESDAY BECOMING IFR TUESDAY NIGHT AND THEN A RETURN TO VFR
CONDITIONS FOR THE MID AND LATTER PART OF THE WEEK.

&&

.MARINE...
SHORT TERM...WILL BE ISSUING GALE WARNINGS FOR MONDAY AFTERNOON
THROUGH MONDAY EVENING FOR THE OUTER WATERS. WINDS WILL JUST TOUCH
GALE FORCE WELL AWAY FROM THE SHORELINE. ALONG THE BAYS...EXPECT
SMALL CRAFT ADVISORY TYPE WINDS INTO TOMORROW EVENING.

LONG TERM...
SCA`S MAY BE NEEDED IN THE SOUTH SOUTHWEST FLOW TUESDAY NIGHT.
THE SCA MAY ALSO BE NEEDED WEDNESDAY NIGHT AND THURSDAY WITH THE
NORTHWEST FLOW.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY FROM NOON TO 11 PM EST MONDAY FOR ANZ151-
     153.
     GALE WARNING FROM NOON TO 11 PM EST MONDAY FOR ANZ150-152-154.

&&

$$
SYNOPSIS...
NEAR TERM...CEMPA
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...




000
FXUS61 KGYX 020453
AFDGYX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
1153 PM EST SUN MAR 1 2015

.SYNOPSIS...
LOW PRESSURE WILL MOVE EAST AND CROSS THE REGION OVERNIGHT...PRODUCING
SOME LIGHT SNOW. A STRONG NORTHWEST FLOW WILL SET UP IN ITS WAKE
ON MONDAY. HIGH PRESSURE WILL BUILD IN FROM THE WEST MONDAY NIGHT
AND WILL CREST OVER THE REGION EARLY TUESDAY BEFORE MOVING
OFFSHORE. LOW PRESSURE WILL SWING THROUGH SOUTHERN CANADA TUESDAY
NIGHT PUSHING A WARM FRONT NORTH ACROSS THE REGION...AND PRODUCING
A PERIOD OF SNOW AND MIXED RAIN OR SNOW ALONG THE COAST. AS THE
LOW SHIFTS TO OUR NORTH...IT WILL DRAG A COLD FRONT THROUGH THE
REGION LATE WEDNESDAY. HIGH PRESSURE WILL BUILD IN FROM THE WEST
THURSDAY AND WILL CREST OVER THE REGION ON FRIDAY.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
1150 PM...HAVE BACKED OFF SNOW ANTS SLIGHTLY ONE MORE TIME...MORE
SO IN THE N WHERE THEY LOOK TO AN INCH. WITH SOME AMTS NEAR 3
INCHES IN SRN NH AND THE THE ME COAST.  STARTING TO SEE DRIER AIR
WORK IN FROM THE NW...CUTTING INTO THE RADAR ECHOES THERE...AND A
DIFFUSE BACK EDGE IN SW NH. A FEW REPORTS FROM SW NH AND YORK
COUNTY ME WITH NEAR 2 INCHES. ECHOES STILL FLARING A BIT EAST OF
CASCO BAY...AND THIS IS WHERE ACCUMS ARE THE BEST BET FOR A FEW
MORE HOURS. SPOTTY LIGHT SNOW LKLY TO CONTINUE TO ABOUT 06-08Z
ELSEWHERE...LITTLE IF ANY ADDL ACCUM IS EXPECTED....AND IT SHOULD
MOVE OUT OF THE MID-COAST BY 09-10Z.

930PM UPDATE...
SNOW IS PROGRESSING ACROSS THE FORECAST AREA THIS EVENING WITH THE
BACK EDGE ALREADY APPEARING IN WESTERN MASSACHUSETTS AND EASTERN
NEW YORK STATE. FEW REPORTS RECEIVED SO FAR HAVE ALL BEEN UNDER 1
INCH. EXPECT STORM TOTALS TO STRUGGLE TO REACH 3 INCHES ALTHOUGH
SOME ENHANCEMENT INLAND OF THE MIDCOAST HAS BEEN NOTED. NO
SIGNIFICANT CHANGES HAVE BEEN MADE TO THE FORECAST.

5PM UPDATE...
HAVE UPDATED PRECIPITATION CHANCES AND SNOWFALL FORECAST OVERNIGHT
AS MORE INTENSE ECHOES NOW SHOWING UP ON RADAR. BEST CHANCE AT
SEEING AN INCH OR TWO WILL BE NEAR THE COAST AND OVER SOUTHERN NEW
HAMPSHIRE WHERE AS MUCH AS 3 INCHES IS POSSIBLE.

ORIGINAL DISCUSSION...
SNOW WILL CONTINUE TO SPREAD EAST THIS EVENING IN ASSOCIATION
WITH BROAD SCALE WARM AIR ADVECTION PATTERN. SOME OF THIS
PRECIPITATION HOWEVER WILL CONTINUE TO SUBLIMATE AS IT INTERACTS
WITH A VERY DRY ATMOSPHERE OVER MAINE AND NEW HAMPSHIRE. EXPECT
PERIODS OF LIGHT SNOW OVERNIGHT. 12Z MODEL SUITE AND MESOSCALE
MODELS HAVE CONTINUED TO BACK OFF ON THE PRECIPITATION FIELDS AND
THEREFORE SNOWFALL AMOUNTS. NEVERTHELESS...THE HIGHEST TOTALS WILL
BE 3-4 INCHES ALONG PORTIONS OF THE MIDCOAST AND OVER FAR SOUTHERN
NH NEAR THE MASSACHUSETTS BORDER. THIS WILL BE JUST BELOW SNOW
ADVISORY CRITERIA.

IT WILL BE A MUCH MILDER NIGHT THAN THOSE OF THE LAST SEVERAL
NIGHTS WITH READINGS BETWEEN 15 AND 25 DEGREES FROM NORTH TO
SOUTH.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
UPPER LEVEL SUPPORT REMAINS DISJOINTED FROM THE SURFACE
REFLECTION ON MONDAY...WITH THE SHORT WAVE CROSSING LAKE ONTARIO
BY EARLY MONDAY MORNING. THERE COULD BE A PASSING SNOW SHOWER WITH
THIS FEATURE. ACROSS THE NORTHWEST FACING HIGHER TERRAIN...SOME
UPSLOPING PRECIPITATION MAY OCCUR.

AS ARCTIC HIGH BUILDS OVER THE REGION...TEMPERATURES WILL ONCE
AGAIN DROP BELOW ZERO IN NORTHERN AREAS. WIND CHILL VALUES WILL BE
HEADING DOWNWARDS AGAIN AS WELL...BRIEFLY APPROACHING WIND CHILL
ADVISORY LEVELS IN THE MOUNTAINS.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
A SUNNY START ON TUESDAY AS HIGH PRESSURE IS CENTERED OVER THE
REGION. INCREASING HIGH CLOUDS WILL SPILL OVER THE SURFACE/UPPER
RIDGE IN THE AFTERNOON AS THE RIDGE AXIS MOVES OFF TO THE EAST.
TUESDAY NIGHT THE SOUTHWEST FLOW ALOFT WILL ALLOW A SHORT WAVE AND
ASSOCIATED WARM FRONT TO MOVE NORTH INTO NORTHERN NEW ENGLAND WITH
WIDESPREAD WARM AIR ADVECTION SNOW EXPECTED. MID/LOW LEVEL
TEMPERATURES SHOULD ALL BE COLD ENOUGH FOR SNOW EXCEPT ALONG THE
IMMEDIATE COAST WHERE A BRIEF MIX WITH RAIN MAY OCCUR BEFORE
ENDING EARLY WEDNESDAY MORNING. A BLEND OF MODELS QPF SUGGESTS A
SNOWFALL OF 2-6 INCHES EXPECTED. ON WEDNESDAY ALL MODELS INDICATE
THE SNOW TO BE OVER BY EARLY MORNING AND THEN SOME CLEARING AND
TEMPERATURES REACHING INTO THE 40S OVER MOST OF THE AREA AS H85
TEMPERATURES REMAIN MILD INTO THE AFTERNOON COMBINED WITH A
DEVELOPING LIGHT DOWNSLOPING WEST WIND. COLD AIR RETURNS FOR
WEDNESDAY NIGHT AND THURSDAY AS HIGH PRESSURE FROM THE GREAT LAKES
BUILDS EAST AND CONTINUES INTO FRIDAY. TEMPERATURES WILL RETURN TO
BELOW NORMAL FOR THURSDAY AND FRIDAY LIKE A BROKEN RECORD.

&&

.AVIATION /06Z MONDAY THROUGH FRIDAY/...
SHORT TERM...CEILINGS AND VISIBILITIES GRADUALLY LOWERING AND
DIMINISHING THIS EVENING IN LIGHT SNOW. IFR CONDITIONS EXPECTED IN
MANY AREAS...ESPECIALLY OVER SOUTHERN LOCATIONS.

LONG TERM...
VFR TUESDAY BECOMING IFR TUESDAY NIGHT AND THEN A RETURN TO VFR
CONDITIONS FOR THE MID AND LATTER PART OF THE WEEK.

&&

.MARINE...
SHORT TERM...WILL BE ISSUING GALE WARNINGS FOR MONDAY AFTERNOON
THROUGH MONDAY EVENING FOR THE OUTER WATERS. WINDS WILL JUST TOUCH
GALE FORCE WELL AWAY FROM THE SHORELINE. ALONG THE BAYS...EXPECT
SMALL CRAFT ADVISORY TYPE WINDS INTO TOMORROW EVENING.

LONG TERM...
SCA`S MAY BE NEEDED IN THE SOUTH SOUTHWEST FLOW TUESDAY NIGHT.
THE SCA MAY ALSO BE NEEDED WEDNESDAY NIGHT AND THURSDAY WITH THE
NORTHWEST FLOW.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY FROM NOON TO 11 PM EST MONDAY FOR ANZ151-
     153.
     GALE WARNING FROM NOON TO 11 PM EST MONDAY FOR ANZ150-152-154.

&&

$$
SYNOPSIS...
NEAR TERM...CEMPA
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...



000
FXUS61 KGYX 020453
AFDGYX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
1153 PM EST SUN MAR 1 2015

.SYNOPSIS...
LOW PRESSURE WILL MOVE EAST AND CROSS THE REGION OVERNIGHT...PRODUCING
SOME LIGHT SNOW. A STRONG NORTHWEST FLOW WILL SET UP IN ITS WAKE
ON MONDAY. HIGH PRESSURE WILL BUILD IN FROM THE WEST MONDAY NIGHT
AND WILL CREST OVER THE REGION EARLY TUESDAY BEFORE MOVING
OFFSHORE. LOW PRESSURE WILL SWING THROUGH SOUTHERN CANADA TUESDAY
NIGHT PUSHING A WARM FRONT NORTH ACROSS THE REGION...AND PRODUCING
A PERIOD OF SNOW AND MIXED RAIN OR SNOW ALONG THE COAST. AS THE
LOW SHIFTS TO OUR NORTH...IT WILL DRAG A COLD FRONT THROUGH THE
REGION LATE WEDNESDAY. HIGH PRESSURE WILL BUILD IN FROM THE WEST
THURSDAY AND WILL CREST OVER THE REGION ON FRIDAY.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
1150 PM...HAVE BACKED OFF SNOW ANTS SLIGHTLY ONE MORE TIME...MORE
SO IN THE N WHERE THEY LOOK TO AN INCH. WITH SOME AMTS NEAR 3
INCHES IN SRN NH AND THE THE ME COAST.  STARTING TO SEE DRIER AIR
WORK IN FROM THE NW...CUTTING INTO THE RADAR ECHOES THERE...AND A
DIFFUSE BACK EDGE IN SW NH. A FEW REPORTS FROM SW NH AND YORK
COUNTY ME WITH NEAR 2 INCHES. ECHOES STILL FLARING A BIT EAST OF
CASCO BAY...AND THIS IS WHERE ACCUMS ARE THE BEST BET FOR A FEW
MORE HOURS. SPOTTY LIGHT SNOW LKLY TO CONTINUE TO ABOUT 06-08Z
ELSEWHERE...LITTLE IF ANY ADDL ACCUM IS EXPECTED....AND IT SHOULD
MOVE OUT OF THE MID-COAST BY 09-10Z.

930PM UPDATE...
SNOW IS PROGRESSING ACROSS THE FORECAST AREA THIS EVENING WITH THE
BACK EDGE ALREADY APPEARING IN WESTERN MASSACHUSETTS AND EASTERN
NEW YORK STATE. FEW REPORTS RECEIVED SO FAR HAVE ALL BEEN UNDER 1
INCH. EXPECT STORM TOTALS TO STRUGGLE TO REACH 3 INCHES ALTHOUGH
SOME ENHANCEMENT INLAND OF THE MIDCOAST HAS BEEN NOTED. NO
SIGNIFICANT CHANGES HAVE BEEN MADE TO THE FORECAST.

5PM UPDATE...
HAVE UPDATED PRECIPITATION CHANCES AND SNOWFALL FORECAST OVERNIGHT
AS MORE INTENSE ECHOES NOW SHOWING UP ON RADAR. BEST CHANCE AT
SEEING AN INCH OR TWO WILL BE NEAR THE COAST AND OVER SOUTHERN NEW
HAMPSHIRE WHERE AS MUCH AS 3 INCHES IS POSSIBLE.

ORIGINAL DISCUSSION...
SNOW WILL CONTINUE TO SPREAD EAST THIS EVENING IN ASSOCIATION
WITH BROAD SCALE WARM AIR ADVECTION PATTERN. SOME OF THIS
PRECIPITATION HOWEVER WILL CONTINUE TO SUBLIMATE AS IT INTERACTS
WITH A VERY DRY ATMOSPHERE OVER MAINE AND NEW HAMPSHIRE. EXPECT
PERIODS OF LIGHT SNOW OVERNIGHT. 12Z MODEL SUITE AND MESOSCALE
MODELS HAVE CONTINUED TO BACK OFF ON THE PRECIPITATION FIELDS AND
THEREFORE SNOWFALL AMOUNTS. NEVERTHELESS...THE HIGHEST TOTALS WILL
BE 3-4 INCHES ALONG PORTIONS OF THE MIDCOAST AND OVER FAR SOUTHERN
NH NEAR THE MASSACHUSETTS BORDER. THIS WILL BE JUST BELOW SNOW
ADVISORY CRITERIA.

IT WILL BE A MUCH MILDER NIGHT THAN THOSE OF THE LAST SEVERAL
NIGHTS WITH READINGS BETWEEN 15 AND 25 DEGREES FROM NORTH TO
SOUTH.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
UPPER LEVEL SUPPORT REMAINS DISJOINTED FROM THE SURFACE
REFLECTION ON MONDAY...WITH THE SHORT WAVE CROSSING LAKE ONTARIO
BY EARLY MONDAY MORNING. THERE COULD BE A PASSING SNOW SHOWER WITH
THIS FEATURE. ACROSS THE NORTHWEST FACING HIGHER TERRAIN...SOME
UPSLOPING PRECIPITATION MAY OCCUR.

AS ARCTIC HIGH BUILDS OVER THE REGION...TEMPERATURES WILL ONCE
AGAIN DROP BELOW ZERO IN NORTHERN AREAS. WIND CHILL VALUES WILL BE
HEADING DOWNWARDS AGAIN AS WELL...BRIEFLY APPROACHING WIND CHILL
ADVISORY LEVELS IN THE MOUNTAINS.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
A SUNNY START ON TUESDAY AS HIGH PRESSURE IS CENTERED OVER THE
REGION. INCREASING HIGH CLOUDS WILL SPILL OVER THE SURFACE/UPPER
RIDGE IN THE AFTERNOON AS THE RIDGE AXIS MOVES OFF TO THE EAST.
TUESDAY NIGHT THE SOUTHWEST FLOW ALOFT WILL ALLOW A SHORT WAVE AND
ASSOCIATED WARM FRONT TO MOVE NORTH INTO NORTHERN NEW ENGLAND WITH
WIDESPREAD WARM AIR ADVECTION SNOW EXPECTED. MID/LOW LEVEL
TEMPERATURES SHOULD ALL BE COLD ENOUGH FOR SNOW EXCEPT ALONG THE
IMMEDIATE COAST WHERE A BRIEF MIX WITH RAIN MAY OCCUR BEFORE
ENDING EARLY WEDNESDAY MORNING. A BLEND OF MODELS QPF SUGGESTS A
SNOWFALL OF 2-6 INCHES EXPECTED. ON WEDNESDAY ALL MODELS INDICATE
THE SNOW TO BE OVER BY EARLY MORNING AND THEN SOME CLEARING AND
TEMPERATURES REACHING INTO THE 40S OVER MOST OF THE AREA AS H85
TEMPERATURES REMAIN MILD INTO THE AFTERNOON COMBINED WITH A
DEVELOPING LIGHT DOWNSLOPING WEST WIND. COLD AIR RETURNS FOR
WEDNESDAY NIGHT AND THURSDAY AS HIGH PRESSURE FROM THE GREAT LAKES
BUILDS EAST AND CONTINUES INTO FRIDAY. TEMPERATURES WILL RETURN TO
BELOW NORMAL FOR THURSDAY AND FRIDAY LIKE A BROKEN RECORD.

&&

.AVIATION /06Z MONDAY THROUGH FRIDAY/...
SHORT TERM...CEILINGS AND VISIBILITIES GRADUALLY LOWERING AND
DIMINISHING THIS EVENING IN LIGHT SNOW. IFR CONDITIONS EXPECTED IN
MANY AREAS...ESPECIALLY OVER SOUTHERN LOCATIONS.

LONG TERM...
VFR TUESDAY BECOMING IFR TUESDAY NIGHT AND THEN A RETURN TO VFR
CONDITIONS FOR THE MID AND LATTER PART OF THE WEEK.

&&

.MARINE...
SHORT TERM...WILL BE ISSUING GALE WARNINGS FOR MONDAY AFTERNOON
THROUGH MONDAY EVENING FOR THE OUTER WATERS. WINDS WILL JUST TOUCH
GALE FORCE WELL AWAY FROM THE SHORELINE. ALONG THE BAYS...EXPECT
SMALL CRAFT ADVISORY TYPE WINDS INTO TOMORROW EVENING.

LONG TERM...
SCA`S MAY BE NEEDED IN THE SOUTH SOUTHWEST FLOW TUESDAY NIGHT.
THE SCA MAY ALSO BE NEEDED WEDNESDAY NIGHT AND THURSDAY WITH THE
NORTHWEST FLOW.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY FROM NOON TO 11 PM EST MONDAY FOR ANZ151-
     153.
     GALE WARNING FROM NOON TO 11 PM EST MONDAY FOR ANZ150-152-154.

&&

$$
SYNOPSIS...
NEAR TERM...CEMPA
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...



000
FXUS61 KGYX 020453
AFDGYX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
1153 PM EST SUN MAR 1 2015

.SYNOPSIS...
LOW PRESSURE WILL MOVE EAST AND CROSS THE REGION OVERNIGHT...PRODUCING
SOME LIGHT SNOW. A STRONG NORTHWEST FLOW WILL SET UP IN ITS WAKE
ON MONDAY. HIGH PRESSURE WILL BUILD IN FROM THE WEST MONDAY NIGHT
AND WILL CREST OVER THE REGION EARLY TUESDAY BEFORE MOVING
OFFSHORE. LOW PRESSURE WILL SWING THROUGH SOUTHERN CANADA TUESDAY
NIGHT PUSHING A WARM FRONT NORTH ACROSS THE REGION...AND PRODUCING
A PERIOD OF SNOW AND MIXED RAIN OR SNOW ALONG THE COAST. AS THE
LOW SHIFTS TO OUR NORTH...IT WILL DRAG A COLD FRONT THROUGH THE
REGION LATE WEDNESDAY. HIGH PRESSURE WILL BUILD IN FROM THE WEST
THURSDAY AND WILL CREST OVER THE REGION ON FRIDAY.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
1150 PM...HAVE BACKED OFF SNOW ANTS SLIGHTLY ONE MORE TIME...MORE
SO IN THE N WHERE THEY LOOK TO AN INCH. WITH SOME AMTS NEAR 3
INCHES IN SRN NH AND THE THE ME COAST.  STARTING TO SEE DRIER AIR
WORK IN FROM THE NW...CUTTING INTO THE RADAR ECHOES THERE...AND A
DIFFUSE BACK EDGE IN SW NH. A FEW REPORTS FROM SW NH AND YORK
COUNTY ME WITH NEAR 2 INCHES. ECHOES STILL FLARING A BIT EAST OF
CASCO BAY...AND THIS IS WHERE ACCUMS ARE THE BEST BET FOR A FEW
MORE HOURS. SPOTTY LIGHT SNOW LKLY TO CONTINUE TO ABOUT 06-08Z
ELSEWHERE...LITTLE IF ANY ADDL ACCUM IS EXPECTED....AND IT SHOULD
MOVE OUT OF THE MID-COAST BY 09-10Z.

930PM UPDATE...
SNOW IS PROGRESSING ACROSS THE FORECAST AREA THIS EVENING WITH THE
BACK EDGE ALREADY APPEARING IN WESTERN MASSACHUSETTS AND EASTERN
NEW YORK STATE. FEW REPORTS RECEIVED SO FAR HAVE ALL BEEN UNDER 1
INCH. EXPECT STORM TOTALS TO STRUGGLE TO REACH 3 INCHES ALTHOUGH
SOME ENHANCEMENT INLAND OF THE MIDCOAST HAS BEEN NOTED. NO
SIGNIFICANT CHANGES HAVE BEEN MADE TO THE FORECAST.

5PM UPDATE...
HAVE UPDATED PRECIPITATION CHANCES AND SNOWFALL FORECAST OVERNIGHT
AS MORE INTENSE ECHOES NOW SHOWING UP ON RADAR. BEST CHANCE AT
SEEING AN INCH OR TWO WILL BE NEAR THE COAST AND OVER SOUTHERN NEW
HAMPSHIRE WHERE AS MUCH AS 3 INCHES IS POSSIBLE.

ORIGINAL DISCUSSION...
SNOW WILL CONTINUE TO SPREAD EAST THIS EVENING IN ASSOCIATION
WITH BROAD SCALE WARM AIR ADVECTION PATTERN. SOME OF THIS
PRECIPITATION HOWEVER WILL CONTINUE TO SUBLIMATE AS IT INTERACTS
WITH A VERY DRY ATMOSPHERE OVER MAINE AND NEW HAMPSHIRE. EXPECT
PERIODS OF LIGHT SNOW OVERNIGHT. 12Z MODEL SUITE AND MESOSCALE
MODELS HAVE CONTINUED TO BACK OFF ON THE PRECIPITATION FIELDS AND
THEREFORE SNOWFALL AMOUNTS. NEVERTHELESS...THE HIGHEST TOTALS WILL
BE 3-4 INCHES ALONG PORTIONS OF THE MIDCOAST AND OVER FAR SOUTHERN
NH NEAR THE MASSACHUSETTS BORDER. THIS WILL BE JUST BELOW SNOW
ADVISORY CRITERIA.

IT WILL BE A MUCH MILDER NIGHT THAN THOSE OF THE LAST SEVERAL
NIGHTS WITH READINGS BETWEEN 15 AND 25 DEGREES FROM NORTH TO
SOUTH.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
UPPER LEVEL SUPPORT REMAINS DISJOINTED FROM THE SURFACE
REFLECTION ON MONDAY...WITH THE SHORT WAVE CROSSING LAKE ONTARIO
BY EARLY MONDAY MORNING. THERE COULD BE A PASSING SNOW SHOWER WITH
THIS FEATURE. ACROSS THE NORTHWEST FACING HIGHER TERRAIN...SOME
UPSLOPING PRECIPITATION MAY OCCUR.

AS ARCTIC HIGH BUILDS OVER THE REGION...TEMPERATURES WILL ONCE
AGAIN DROP BELOW ZERO IN NORTHERN AREAS. WIND CHILL VALUES WILL BE
HEADING DOWNWARDS AGAIN AS WELL...BRIEFLY APPROACHING WIND CHILL
ADVISORY LEVELS IN THE MOUNTAINS.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
A SUNNY START ON TUESDAY AS HIGH PRESSURE IS CENTERED OVER THE
REGION. INCREASING HIGH CLOUDS WILL SPILL OVER THE SURFACE/UPPER
RIDGE IN THE AFTERNOON AS THE RIDGE AXIS MOVES OFF TO THE EAST.
TUESDAY NIGHT THE SOUTHWEST FLOW ALOFT WILL ALLOW A SHORT WAVE AND
ASSOCIATED WARM FRONT TO MOVE NORTH INTO NORTHERN NEW ENGLAND WITH
WIDESPREAD WARM AIR ADVECTION SNOW EXPECTED. MID/LOW LEVEL
TEMPERATURES SHOULD ALL BE COLD ENOUGH FOR SNOW EXCEPT ALONG THE
IMMEDIATE COAST WHERE A BRIEF MIX WITH RAIN MAY OCCUR BEFORE
ENDING EARLY WEDNESDAY MORNING. A BLEND OF MODELS QPF SUGGESTS A
SNOWFALL OF 2-6 INCHES EXPECTED. ON WEDNESDAY ALL MODELS INDICATE
THE SNOW TO BE OVER BY EARLY MORNING AND THEN SOME CLEARING AND
TEMPERATURES REACHING INTO THE 40S OVER MOST OF THE AREA AS H85
TEMPERATURES REMAIN MILD INTO THE AFTERNOON COMBINED WITH A
DEVELOPING LIGHT DOWNSLOPING WEST WIND. COLD AIR RETURNS FOR
WEDNESDAY NIGHT AND THURSDAY AS HIGH PRESSURE FROM THE GREAT LAKES
BUILDS EAST AND CONTINUES INTO FRIDAY. TEMPERATURES WILL RETURN TO
BELOW NORMAL FOR THURSDAY AND FRIDAY LIKE A BROKEN RECORD.

&&

.AVIATION /06Z MONDAY THROUGH FRIDAY/...
SHORT TERM...CEILINGS AND VISIBILITIES GRADUALLY LOWERING AND
DIMINISHING THIS EVENING IN LIGHT SNOW. IFR CONDITIONS EXPECTED IN
MANY AREAS...ESPECIALLY OVER SOUTHERN LOCATIONS.

LONG TERM...
VFR TUESDAY BECOMING IFR TUESDAY NIGHT AND THEN A RETURN TO VFR
CONDITIONS FOR THE MID AND LATTER PART OF THE WEEK.

&&

.MARINE...
SHORT TERM...WILL BE ISSUING GALE WARNINGS FOR MONDAY AFTERNOON
THROUGH MONDAY EVENING FOR THE OUTER WATERS. WINDS WILL JUST TOUCH
GALE FORCE WELL AWAY FROM THE SHORELINE. ALONG THE BAYS...EXPECT
SMALL CRAFT ADVISORY TYPE WINDS INTO TOMORROW EVENING.

LONG TERM...
SCA`S MAY BE NEEDED IN THE SOUTH SOUTHWEST FLOW TUESDAY NIGHT.
THE SCA MAY ALSO BE NEEDED WEDNESDAY NIGHT AND THURSDAY WITH THE
NORTHWEST FLOW.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY FROM NOON TO 11 PM EST MONDAY FOR ANZ151-
     153.
     GALE WARNING FROM NOON TO 11 PM EST MONDAY FOR ANZ150-152-154.

&&

$$
SYNOPSIS...
NEAR TERM...CEMPA
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...



000
FXUS61 KGYX 020453
AFDGYX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
1153 PM EST SUN MAR 1 2015

.SYNOPSIS...
LOW PRESSURE WILL MOVE EAST AND CROSS THE REGION OVERNIGHT...PRODUCING
SOME LIGHT SNOW. A STRONG NORTHWEST FLOW WILL SET UP IN ITS WAKE
ON MONDAY. HIGH PRESSURE WILL BUILD IN FROM THE WEST MONDAY NIGHT
AND WILL CREST OVER THE REGION EARLY TUESDAY BEFORE MOVING
OFFSHORE. LOW PRESSURE WILL SWING THROUGH SOUTHERN CANADA TUESDAY
NIGHT PUSHING A WARM FRONT NORTH ACROSS THE REGION...AND PRODUCING
A PERIOD OF SNOW AND MIXED RAIN OR SNOW ALONG THE COAST. AS THE
LOW SHIFTS TO OUR NORTH...IT WILL DRAG A COLD FRONT THROUGH THE
REGION LATE WEDNESDAY. HIGH PRESSURE WILL BUILD IN FROM THE WEST
THURSDAY AND WILL CREST OVER THE REGION ON FRIDAY.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
1150 PM...HAVE BACKED OFF SNOW ANTS SLIGHTLY ONE MORE TIME...MORE
SO IN THE N WHERE THEY LOOK TO AN INCH. WITH SOME AMTS NEAR 3
INCHES IN SRN NH AND THE THE ME COAST.  STARTING TO SEE DRIER AIR
WORK IN FROM THE NW...CUTTING INTO THE RADAR ECHOES THERE...AND A
DIFFUSE BACK EDGE IN SW NH. A FEW REPORTS FROM SW NH AND YORK
COUNTY ME WITH NEAR 2 INCHES. ECHOES STILL FLARING A BIT EAST OF
CASCO BAY...AND THIS IS WHERE ACCUMS ARE THE BEST BET FOR A FEW
MORE HOURS. SPOTTY LIGHT SNOW LKLY TO CONTINUE TO ABOUT 06-08Z
ELSEWHERE...LITTLE IF ANY ADDL ACCUM IS EXPECTED....AND IT SHOULD
MOVE OUT OF THE MID-COAST BY 09-10Z.

930PM UPDATE...
SNOW IS PROGRESSING ACROSS THE FORECAST AREA THIS EVENING WITH THE
BACK EDGE ALREADY APPEARING IN WESTERN MASSACHUSETTS AND EASTERN
NEW YORK STATE. FEW REPORTS RECEIVED SO FAR HAVE ALL BEEN UNDER 1
INCH. EXPECT STORM TOTALS TO STRUGGLE TO REACH 3 INCHES ALTHOUGH
SOME ENHANCEMENT INLAND OF THE MIDCOAST HAS BEEN NOTED. NO
SIGNIFICANT CHANGES HAVE BEEN MADE TO THE FORECAST.

5PM UPDATE...
HAVE UPDATED PRECIPITATION CHANCES AND SNOWFALL FORECAST OVERNIGHT
AS MORE INTENSE ECHOES NOW SHOWING UP ON RADAR. BEST CHANCE AT
SEEING AN INCH OR TWO WILL BE NEAR THE COAST AND OVER SOUTHERN NEW
HAMPSHIRE WHERE AS MUCH AS 3 INCHES IS POSSIBLE.

ORIGINAL DISCUSSION...
SNOW WILL CONTINUE TO SPREAD EAST THIS EVENING IN ASSOCIATION
WITH BROAD SCALE WARM AIR ADVECTION PATTERN. SOME OF THIS
PRECIPITATION HOWEVER WILL CONTINUE TO SUBLIMATE AS IT INTERACTS
WITH A VERY DRY ATMOSPHERE OVER MAINE AND NEW HAMPSHIRE. EXPECT
PERIODS OF LIGHT SNOW OVERNIGHT. 12Z MODEL SUITE AND MESOSCALE
MODELS HAVE CONTINUED TO BACK OFF ON THE PRECIPITATION FIELDS AND
THEREFORE SNOWFALL AMOUNTS. NEVERTHELESS...THE HIGHEST TOTALS WILL
BE 3-4 INCHES ALONG PORTIONS OF THE MIDCOAST AND OVER FAR SOUTHERN
NH NEAR THE MASSACHUSETTS BORDER. THIS WILL BE JUST BELOW SNOW
ADVISORY CRITERIA.

IT WILL BE A MUCH MILDER NIGHT THAN THOSE OF THE LAST SEVERAL
NIGHTS WITH READINGS BETWEEN 15 AND 25 DEGREES FROM NORTH TO
SOUTH.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
UPPER LEVEL SUPPORT REMAINS DISJOINTED FROM THE SURFACE
REFLECTION ON MONDAY...WITH THE SHORT WAVE CROSSING LAKE ONTARIO
BY EARLY MONDAY MORNING. THERE COULD BE A PASSING SNOW SHOWER WITH
THIS FEATURE. ACROSS THE NORTHWEST FACING HIGHER TERRAIN...SOME
UPSLOPING PRECIPITATION MAY OCCUR.

AS ARCTIC HIGH BUILDS OVER THE REGION...TEMPERATURES WILL ONCE
AGAIN DROP BELOW ZERO IN NORTHERN AREAS. WIND CHILL VALUES WILL BE
HEADING DOWNWARDS AGAIN AS WELL...BRIEFLY APPROACHING WIND CHILL
ADVISORY LEVELS IN THE MOUNTAINS.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
A SUNNY START ON TUESDAY AS HIGH PRESSURE IS CENTERED OVER THE
REGION. INCREASING HIGH CLOUDS WILL SPILL OVER THE SURFACE/UPPER
RIDGE IN THE AFTERNOON AS THE RIDGE AXIS MOVES OFF TO THE EAST.
TUESDAY NIGHT THE SOUTHWEST FLOW ALOFT WILL ALLOW A SHORT WAVE AND
ASSOCIATED WARM FRONT TO MOVE NORTH INTO NORTHERN NEW ENGLAND WITH
WIDESPREAD WARM AIR ADVECTION SNOW EXPECTED. MID/LOW LEVEL
TEMPERATURES SHOULD ALL BE COLD ENOUGH FOR SNOW EXCEPT ALONG THE
IMMEDIATE COAST WHERE A BRIEF MIX WITH RAIN MAY OCCUR BEFORE
ENDING EARLY WEDNESDAY MORNING. A BLEND OF MODELS QPF SUGGESTS A
SNOWFALL OF 2-6 INCHES EXPECTED. ON WEDNESDAY ALL MODELS INDICATE
THE SNOW TO BE OVER BY EARLY MORNING AND THEN SOME CLEARING AND
TEMPERATURES REACHING INTO THE 40S OVER MOST OF THE AREA AS H85
TEMPERATURES REMAIN MILD INTO THE AFTERNOON COMBINED WITH A
DEVELOPING LIGHT DOWNSLOPING WEST WIND. COLD AIR RETURNS FOR
WEDNESDAY NIGHT AND THURSDAY AS HIGH PRESSURE FROM THE GREAT LAKES
BUILDS EAST AND CONTINUES INTO FRIDAY. TEMPERATURES WILL RETURN TO
BELOW NORMAL FOR THURSDAY AND FRIDAY LIKE A BROKEN RECORD.

&&

.AVIATION /06Z MONDAY THROUGH FRIDAY/...
SHORT TERM...CEILINGS AND VISIBILITIES GRADUALLY LOWERING AND
DIMINISHING THIS EVENING IN LIGHT SNOW. IFR CONDITIONS EXPECTED IN
MANY AREAS...ESPECIALLY OVER SOUTHERN LOCATIONS.

LONG TERM...
VFR TUESDAY BECOMING IFR TUESDAY NIGHT AND THEN A RETURN TO VFR
CONDITIONS FOR THE MID AND LATTER PART OF THE WEEK.

&&

.MARINE...
SHORT TERM...WILL BE ISSUING GALE WARNINGS FOR MONDAY AFTERNOON
THROUGH MONDAY EVENING FOR THE OUTER WATERS. WINDS WILL JUST TOUCH
GALE FORCE WELL AWAY FROM THE SHORELINE. ALONG THE BAYS...EXPECT
SMALL CRAFT ADVISORY TYPE WINDS INTO TOMORROW EVENING.

LONG TERM...
SCA`S MAY BE NEEDED IN THE SOUTH SOUTHWEST FLOW TUESDAY NIGHT.
THE SCA MAY ALSO BE NEEDED WEDNESDAY NIGHT AND THURSDAY WITH THE
NORTHWEST FLOW.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY FROM NOON TO 11 PM EST MONDAY FOR ANZ151-
     153.
     GALE WARNING FROM NOON TO 11 PM EST MONDAY FOR ANZ150-152-154.

&&

$$
SYNOPSIS...
NEAR TERM...CEMPA
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...



000
FXUS61 KBOX 020351
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
1050 PM EST SUN MAR 1 2015

.SYNOPSIS...
A FAST MOVING LOW PRESSURE SYSTEM WILL BRING ACCUMULATING SNOW
THIS EVENING AND TONIGHT WITH THE HIGHEST AMOUNTS EXPECTED SOUTH
OF THE MASSACHUSETTS TURNPIKE. HIGH PRESSURE BRINGS DRY COLD AIR
FOR THE EARLY WEEK. LOW PRESSURE FROM NORTHERN CANADA AND
ASSOCIATED LOW FORMING OVER THE PLAINS MONDAY WILL MERGE...THEN
PASS WEST AND NORTH OF NEW ENGLAND. THIS WILL SWING A COLD FRONT
ACROSS THE REGION ON WEDNESDAY. DRY AND COLD WEATHER RETURNS FOR
THE END OF THE WEEK. ANOTHER COLD FRONT MOVES THROUGH ON SATURDAY.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...

1050 PM UPDATE...

BAND OF MODERATE TO HEAVY SNOW CONTINUES TO AFFECT RHODE ISLAND AND
SOUTHEAST MA LATE THIS EVENING.  PTYPE HAS CHANGED TO RAIN AND EVEN
SOME FREEZING RAIN ACROSS THE ISLANDS AND ONTO PORTIONS OF SOUTHERN
MOST CAPE COD.  THAT RAIN/FREEZING RAIN LINE SHOULD NOT MAKE IT TOO
MUCH FURTHER NORTH...BUT MAY AFFECT JUST THE IMMEDIATE SHORELINES
AROUND BUZZARDS BAY AND PORTIONS OF CAPE COD BAY.  MEANWHILE...LIGHT
TO BRIEFLY MODERATE SNOW CONTINUES ACROSS THE REST OF THE REGION AS
A RESULT OF SOME BROAD SCALE LIFT.

OVERALL...EXPECT THE ACCUMULATING SNOW TO BE WINDING DOWN BETWEEN
MIDNIGHT AND 2 AM AS SYSTEM IS QUITE PROGRESSIVE.  TOTAL
ACCUMULATIONS OF 2 TO 4 INCHES NORTH OF THE PIKE AND 3 TO 6 INCHES
SOUTH OF PIKE...WHERE WINTER WEATHER ADVISORIES CONTINUE.  WINTER
STORM WARNING FOR BETWEEN 4 AND 8 INCHES CONTINUES ACROSS MUCH OF
RHODE ISLAND AND SOUTHEAST MA...WHERE WE HAVE HAD A FEW REPORTS UP
TO 6 INCHES ALREADY.  AGAIN...RAIN/SNOW LINE PRETTY MUCH WILL HANG
THE SHORES OF BUZZARDS BAY AND INTO PART OF CAPE COD.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
MONDAY...
PRECIPITATION WILL HAVE LARGELY COME TO AN END FOR DAYBREAK MONDAY
WITH THE LOW PRESSURE RAPIDLY PULLING AWAY INTO THE CANADIAN
MARITIMES AND DRIER AIR/HIGH PRESSURE MOVING IN FROM THE WEST.
INCREASING SUNSHINE EXPECTED DURING THE DAY...WITH TEMPS TOPPING
OUT IN THE UPPER 20S TO MID 30S. HOWEVER AS WE GET TOWARDS
MIDDAY/AFTERNOON TIGHTENING GRADIENT WILL ALLOW NORTHWEST FLOW TO
BECOME BLUSTERY...WITH GUSTS OF 25 TO 30 MPH...25 TO 35 MPH ON THE
CAPE AND ISLANDS.

MONDAY NIGHT...
HIGH PRESSURE SETTLES OVER THE AREA WITH CLEAR SKIES EXPECTED.
GIVEN OUR SNOWPACK IN PLACE AND LIGHT WINDS...SHOULD BE ANOTHER
NIGHT FOR EXCELLENT RADIATIONAL COOLING. BECAUSE OF THIS DID
GENERALLY GO BELOW MODEL GUIDANCE FOR MIN TEMPS...LOOKING TO
ANTICIPATED SURFACE DEWPOINTS FOR A GUIDELINE ON HOW LOW WE CAN
GO. MAY SEE SOME SPOTS IN THE INTERIOR DROP BELOW ZERO.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
BIG PICTURE... THE BROAD UPPER FLOW CONTINUES TO FEATURE A TROUGH
TRANSITING EAST ACROSS THE COUNTRY...REACHING THE EASTERN USA DURING
THE LATE WEEK AND LINGERING THROUGH THE WEEKEND. MEANWHILE AN UPPER
RIDGE SHIFTS FROM THE PACIFIC OCEAN BACK ASHORE ONTO THE WEST COAST.
CONTOUR HEIGHTS IN THE TROUGH ARE LOWEST THURSDAY-FRIDAY AND NEAR
NORMAL OVER THE WEEKEND. THIS MEANS A TREND TO COLDER TEMPS THURSDAY-
FRIDAY FOLLOWED BY A TREND CLOSER TO NORMAL OVER THE WEEKEND.

DAILIES...

TUESDAY... HIGH PRESSURE OVER THE REGION MOVES OFFSHORE BY AFTERNOON
WITH AIRFLOW SWINGING FROM NORTHWEST TO SOUTHWEST. THE SURFACE
AIRMASS STARTS OUT QUITE DRY WITH DEW POINTS IN THE SINGLE NUMBERS
BELOW ZERO TO START...CLIMBING TO 5-10 ABOVE BY EVENING. MODEL CROSS
SECTIONS SHOW INCREASING MOISTURE MORNING AND AFTERNOON ABOVE 700
MB. THIS SUGGESTS INCREASING MID AND HIGH CLOUDS WHILE DRY BENEATH.
LOW LEVEL JETS FROM THE CAROLINAS AND MIDWEST AND THE SURFACE
PRESSURE GRADIENT ALL SUGGEST THE INFLOW AND ISENTROPIC LIFT WILL
REMAIN TO OUR WEST THROUGH THE DAY...POSSIBLY ENTERING WESTERN MA/CT
AT OR AFTER 21Z. SO WE EXPECT INCREASING CLOUDS TUESDAY BUT
OTHERWISE DRY WEATHER THROUGH THE DAY. POSSIBLE LIGHT SNOW AROUND
THE EVENING RUSH HOUR IN THE CT RIVER VALLEY. TEMPS SHOULD REACH THE
MID 20S TO AROUND 30.

TUESDAY NIGHT-WEDNESDAY... NORTHERN AND SOUTHERN STREAM SHORTWAVES
MERGE OVER THE GREAT LAKES AND TRACK INTO CANADA. THIS BRINGS A MILD
FLOW OF AIR UP OVER NEW ENGLAND. THE LEADING EDGE OF THIS AIR
REACHES WESTERN SECTIONS TUESDAY EVENING AND EASTERN SECTIONS
TUESDAY NIGHT. TEMPERATURE PROFILES SUPPORT AN INITIAL PERIOD OF
SNOW CHANGING TO RAIN OR FREEZING RAIN OVERNIGHT. ACTUALLY...THE
MODELS MAY NOT BE HANDLING WELL THE CHILLING MASS OF SNOW AND COLD
GROUND /A.K.A. THE GIANT ICECUBE/ WHICH WOULD MEAN THE ACTUAL MAX
SFC TEMPS WILL BE COOLER THAN MODEL FORECASTS. TEMPERATURES AT 925
AND 950 MB WILL BE IN THE 30S...SO EXPECT SURFACE TEMPS NO HIGHER
THAN THE LOWER 40S.

THE SURFACE LOW PRESSURE AREA PASSES WELL NORTH OF NEW ENGLAND
WEDNESDAY AND SWINGS A COLD FRONT THROUGH THE REGION DURING THE
AFTERNOON OR EVENING. MOISTURE CROSS SECTIONS SHOW DECREASING RH IN
THE LIFT AND NUCLEATION ZONES ALOFT WEDNESDAY MORNING...SO THE TREND
THROUGH THE DAY SHOULD BE TO DIMINISHING POPS.

THURSDAY-FRIDAY... THE WEDNESDAY COLD FRONT WILL ALIGN WITH THE
UPPER FLOW AS IT MOVES SOUTH OF NEW ENGLAND...SLOWING ITS OFFSHORE
PROGRESS TO A CRAWL. MEANWHILE WE WILL BE UNDER THE RIGHT ENTRANCE
REGION OF THE SUPPORTING UPPER JET...A SOURCE OF UPPER VENTING. THIS
SHOULD SUPPORT LINGERING CLOUDS AND A CHANCE OF PCPN...WITH TEMPS
SUPPORTIVE OF SNOW. BEST CHANCE SOUTH COAST...LESSER CHANCE FARTHER
NORTH. THE JET AND SURFACE FRONT SWEEP OFFSHORE THURSDAY NIGHT. HIGH
PRESSURE THEN MOVES OVER THE EASTERN USA FOR FRIDAY. TEMPS ALOFT
SUPPORT MAX SFC TEMPS IN THE 20S.

SATURDAY-SUNDAY... ANOTHER NORTHERN STREAM SHORTWAVE AND COLD FRONT
SWINGS THROUGH THE FLOW SATURDAY. CROSS SECTIONS SHOW SOME MOISTURE
ALOFT BUT MOST OF IT IS CONCENTRATED TO OUR NORTH.  ALSO JUST
LIMITED LIFT TO WORK ON THAT MOISTURE. WE WILL HAVE 25-50 PCT SKY
COVER AND NIL POPS. HIGH PRESSURE THEN BUILDS FOR SUNDAY.

&&

.AVIATION /04Z MONDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...

TONIGHT...MODERATE CONFIDENCE. MVFR CIGS WITH PATCHES OF IFR
VALUES. VSBYS MOSTLY 1 TO 3 MILES WITH A ZONE FROM SOUTHERN CT
THROUGH RI AND SE MASS WHERE VSBYS ARE LIFR AT 1/2 MILE TO 1 MILE.
EXPECT THESE CONDITIONS TO LINGER THROUGH MIDNIGHT. THE ZONE OF
LOWER VSBYS AND SNOWFALL RATES COULD WOBBLE NORTH A FEW MILES AND
BRIEFLY APPROACH BOSTON BUT SHOULD PRIMARILY REMAIN TO THE SOUTH.

SOUTH FLOW BRINGS ENOUGH MILDER AIR NORTH TO MIX OR CHANGE THE
PCPN TO RAIN ON NANTUCKET AND PARTS OF THE OUTER CAPE. BULK OF THE
SNOW SHOULD ENDS 06Z WEST TO 10Z EAST /LATE TONIGHT AND EARLY
MONDAY/ MUCH OF THE REGION SHOULD IMPROVE TO VFR CONDITIONS BY
12-13Z MONDAY.

KBOS TAF...CONFIDENT IN OVERALL TRENDS BUT THERE IS UNCERTAINTY ON
TIMING. VSBYS BELOW 1 MILE SHOULD REMAIN TO THE SOUTH BUT COULD
BRIEFLY VISIT THE AIRPORT EARLY TONIGHT. THE BULK OF ACCUMULATING
SNOW IS EXPECTED BY MIDNIGHT.

KBDL TAF...CONFIDENT IN OVERALL TRENDS BUT THERE IS UNCERTAINTY ON
TIMING. BULK OF ACCUMULATING SNOW WITH IFR TO LIFR CONDITIONS
EXPECTED BY MIDNIGHT.

MONDAY AND MONDAY NIGHT...HIGH CONFIDENCE VFR. NORTHWEST WINDS
GUSTING TO 25 TO 30 MPH ACROSS MUCH OF THE AREA DURING MONDAY
AFTERNOON...25 TO 35 MPH GUSTS CAPE/ISLANDS. WINDS DIMINISHING
TOWARDS SUNSET.

OUTLOOK...TUESDAY THROUGH FRIDAY...

TUESDAY...MODERATE CONFIDENCE. VFR DURING THE DAY WITH INCREASING
SKY COVER. MVFR CIGS/VSBYS POSSIBLE LATE IN THE DAY CT RIVER VALLEY.

TUESDAY NIGHT-WEDNESDAY...MODERATE CONFIDENCE. CONDITIONS LOWERING
TO IFR/LIFR. INITIALLY SNOW BUT CHANGING TO SLEET/FREEZING RAIN
DURING THE NIGHT AND RAIN IN THE COASTAL PLAIN OVERNIGHT. PCPN
CHANGES TO RAIN ALL AREAS WEDNESDAY...BUT COLD SURFACES COULD
MAINTAIN A FREEZING RAIN ELEMENT WEDNESDAY MORNING. COLDER AIR MOVES
IN WEDNESDAY NIGHT CHANGING ANY RAIN TO SNOW.

THURSDAY...LOW CONFIDENCE. VFR NORTH OF A HFD-BOS LINE. MVFR CIGS
AND AREAS OF MVFR/IFR VSBYS IN SNOW...DIMINISHING BY EVENING.
NORTHWEST WINDS GUSTING TO 20 KNOTS.

FRIDAY...MODERATE CONFIDENCE. VFR.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...HIGH CONFIDENCE.

A WEAK WAVE OF LOW PRESSURE MOVES ACROSS THE WATERS TONIGHT.
THIS SYSTEM REALLY INTENSIFIES AS IT MOVES INTO THE CANADIAN
MARITIMES NEAR DAYBREAK MONDAY...SO WESTERLY WIND GUSTS MAY REACH
20 TO 25 KNOTS NEAR 12Z MONDAY. OTHERWISE...RAIN AND SNOW THIS
EVENING AND TONIGHT WILL REDUCE VISIBILITIES AT TIMES FOR
MARINERS.

MONDAY...AS THE LOW PRESSURE GOING INTO THE CANADIAN MARITIMES
INTENSIFIES...INCREASING NORTHWEST WINDS ARE EXPECTED OVER THE
SOUTHERN NEW ENGLAND COASTAL WATERS...WITH GALE FORCE GUSTS
EXPECTED. GALE WARNINGS HAVE BEEN HOISTED FOR ALL COASTAL WATERS
FROM MIDDAY MONDAY INTO MONDAY NIGHT.

OUTLOOK...TUESDAY THROUGH FRIDAY..MODERATE CONFIDENCE.

TUESDAY... LINGERING 5 FOOT SEAS SOUTH AND EAST OF NANTUCKET IN THE
MORNING BUT DIMINISHING. NORTHWEST WINDS DIMINISHING FROM 20 KNOTS.
ANY SMALL CRAFT ADVISORY SHOULD END IN THE MORNING.

TUESDAY NIGHT-WEDNESDAY...SOUTH TO SOUTHWEST WINDS WILL INCREASE TO
20-25 KNOTS. SEAS WILL BUILD 6 TO 10 FEET ON THE OUTER WATERS AND ON
RI SOUND. REDUCED VSBYS...INITIALLY SNOW BUT CHANGING TO RAIN. A
SMALL CRAFT ADVISORY MAY BE NEEDED.

THURSDAY...NORTHWEST WIND GUSTING TO 25 KNOTS. SEAS 5 TO 8 FEET
MAINLY ON THE OUTER WATERS...DIMINISHING LATE. A SMALL CRAFT
ADVISORY MAY BE NEEDED.

FRIDAY... SHIFTING WINDS LESS THAN 20 KNOTS. SEAS LESS THAN 5 FEET.
QUIET WEATHER.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WINTER WEATHER ADVISORY UNTIL 4 AM EST MONDAY FOR CTZ002>004.
MA...WINTER STORM WARNING UNTIL 4 AM EST MONDAY FOR MAZ017>021.
     WINTER WEATHER ADVISORY UNTIL 4 AM EST MONDAY FOR MAZ002>016-
     022-023-026.
RI...WINTER STORM WARNING UNTIL 4 AM EST MONDAY FOR RIZ002>008.
     WINTER WEATHER ADVISORY UNTIL 4 AM EST MONDAY FOR RIZ001.
MARINE...GALE WARNING FROM 11 AM MONDAY TO 4 AM EST TUESDAY FOR ANZ231-
     232-250-251-254-255.
     GALE WARNING FROM 11 AM TO 11 PM EST MONDAY FOR ANZ233>235-237-
     256.
     GALE WARNING FROM 11 AM TO 8 PM EST MONDAY FOR ANZ230-236.

&&

$$
SYNOPSIS...WTB/NMB
NEAR TERM...FRANK
SHORT TERM...NMB
LONG TERM...WTB
AVIATION...WTB/NMB
MARINE...WTB/NMB



000
FXUS61 KBOX 020351
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
1050 PM EST SUN MAR 1 2015

.SYNOPSIS...
A FAST MOVING LOW PRESSURE SYSTEM WILL BRING ACCUMULATING SNOW
THIS EVENING AND TONIGHT WITH THE HIGHEST AMOUNTS EXPECTED SOUTH
OF THE MASSACHUSETTS TURNPIKE. HIGH PRESSURE BRINGS DRY COLD AIR
FOR THE EARLY WEEK. LOW PRESSURE FROM NORTHERN CANADA AND
ASSOCIATED LOW FORMING OVER THE PLAINS MONDAY WILL MERGE...THEN
PASS WEST AND NORTH OF NEW ENGLAND. THIS WILL SWING A COLD FRONT
ACROSS THE REGION ON WEDNESDAY. DRY AND COLD WEATHER RETURNS FOR
THE END OF THE WEEK. ANOTHER COLD FRONT MOVES THROUGH ON SATURDAY.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...

1050 PM UPDATE...

BAND OF MODERATE TO HEAVY SNOW CONTINUES TO AFFECT RHODE ISLAND AND
SOUTHEAST MA LATE THIS EVENING.  PTYPE HAS CHANGED TO RAIN AND EVEN
SOME FREEZING RAIN ACROSS THE ISLANDS AND ONTO PORTIONS OF SOUTHERN
MOST CAPE COD.  THAT RAIN/FREEZING RAIN LINE SHOULD NOT MAKE IT TOO
MUCH FURTHER NORTH...BUT MAY AFFECT JUST THE IMMEDIATE SHORELINES
AROUND BUZZARDS BAY AND PORTIONS OF CAPE COD BAY.  MEANWHILE...LIGHT
TO BRIEFLY MODERATE SNOW CONTINUES ACROSS THE REST OF THE REGION AS
A RESULT OF SOME BROAD SCALE LIFT.

OVERALL...EXPECT THE ACCUMULATING SNOW TO BE WINDING DOWN BETWEEN
MIDNIGHT AND 2 AM AS SYSTEM IS QUITE PROGRESSIVE.  TOTAL
ACCUMULATIONS OF 2 TO 4 INCHES NORTH OF THE PIKE AND 3 TO 6 INCHES
SOUTH OF PIKE...WHERE WINTER WEATHER ADVISORIES CONTINUE.  WINTER
STORM WARNING FOR BETWEEN 4 AND 8 INCHES CONTINUES ACROSS MUCH OF
RHODE ISLAND AND SOUTHEAST MA...WHERE WE HAVE HAD A FEW REPORTS UP
TO 6 INCHES ALREADY.  AGAIN...RAIN/SNOW LINE PRETTY MUCH WILL HANG
THE SHORES OF BUZZARDS BAY AND INTO PART OF CAPE COD.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
MONDAY...
PRECIPITATION WILL HAVE LARGELY COME TO AN END FOR DAYBREAK MONDAY
WITH THE LOW PRESSURE RAPIDLY PULLING AWAY INTO THE CANADIAN
MARITIMES AND DRIER AIR/HIGH PRESSURE MOVING IN FROM THE WEST.
INCREASING SUNSHINE EXPECTED DURING THE DAY...WITH TEMPS TOPPING
OUT IN THE UPPER 20S TO MID 30S. HOWEVER AS WE GET TOWARDS
MIDDAY/AFTERNOON TIGHTENING GRADIENT WILL ALLOW NORTHWEST FLOW TO
BECOME BLUSTERY...WITH GUSTS OF 25 TO 30 MPH...25 TO 35 MPH ON THE
CAPE AND ISLANDS.

MONDAY NIGHT...
HIGH PRESSURE SETTLES OVER THE AREA WITH CLEAR SKIES EXPECTED.
GIVEN OUR SNOWPACK IN PLACE AND LIGHT WINDS...SHOULD BE ANOTHER
NIGHT FOR EXCELLENT RADIATIONAL COOLING. BECAUSE OF THIS DID
GENERALLY GO BELOW MODEL GUIDANCE FOR MIN TEMPS...LOOKING TO
ANTICIPATED SURFACE DEWPOINTS FOR A GUIDELINE ON HOW LOW WE CAN
GO. MAY SEE SOME SPOTS IN THE INTERIOR DROP BELOW ZERO.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
BIG PICTURE... THE BROAD UPPER FLOW CONTINUES TO FEATURE A TROUGH
TRANSITING EAST ACROSS THE COUNTRY...REACHING THE EASTERN USA DURING
THE LATE WEEK AND LINGERING THROUGH THE WEEKEND. MEANWHILE AN UPPER
RIDGE SHIFTS FROM THE PACIFIC OCEAN BACK ASHORE ONTO THE WEST COAST.
CONTOUR HEIGHTS IN THE TROUGH ARE LOWEST THURSDAY-FRIDAY AND NEAR
NORMAL OVER THE WEEKEND. THIS MEANS A TREND TO COLDER TEMPS THURSDAY-
FRIDAY FOLLOWED BY A TREND CLOSER TO NORMAL OVER THE WEEKEND.

DAILIES...

TUESDAY... HIGH PRESSURE OVER THE REGION MOVES OFFSHORE BY AFTERNOON
WITH AIRFLOW SWINGING FROM NORTHWEST TO SOUTHWEST. THE SURFACE
AIRMASS STARTS OUT QUITE DRY WITH DEW POINTS IN THE SINGLE NUMBERS
BELOW ZERO TO START...CLIMBING TO 5-10 ABOVE BY EVENING. MODEL CROSS
SECTIONS SHOW INCREASING MOISTURE MORNING AND AFTERNOON ABOVE 700
MB. THIS SUGGESTS INCREASING MID AND HIGH CLOUDS WHILE DRY BENEATH.
LOW LEVEL JETS FROM THE CAROLINAS AND MIDWEST AND THE SURFACE
PRESSURE GRADIENT ALL SUGGEST THE INFLOW AND ISENTROPIC LIFT WILL
REMAIN TO OUR WEST THROUGH THE DAY...POSSIBLY ENTERING WESTERN MA/CT
AT OR AFTER 21Z. SO WE EXPECT INCREASING CLOUDS TUESDAY BUT
OTHERWISE DRY WEATHER THROUGH THE DAY. POSSIBLE LIGHT SNOW AROUND
THE EVENING RUSH HOUR IN THE CT RIVER VALLEY. TEMPS SHOULD REACH THE
MID 20S TO AROUND 30.

TUESDAY NIGHT-WEDNESDAY... NORTHERN AND SOUTHERN STREAM SHORTWAVES
MERGE OVER THE GREAT LAKES AND TRACK INTO CANADA. THIS BRINGS A MILD
FLOW OF AIR UP OVER NEW ENGLAND. THE LEADING EDGE OF THIS AIR
REACHES WESTERN SECTIONS TUESDAY EVENING AND EASTERN SECTIONS
TUESDAY NIGHT. TEMPERATURE PROFILES SUPPORT AN INITIAL PERIOD OF
SNOW CHANGING TO RAIN OR FREEZING RAIN OVERNIGHT. ACTUALLY...THE
MODELS MAY NOT BE HANDLING WELL THE CHILLING MASS OF SNOW AND COLD
GROUND /A.K.A. THE GIANT ICECUBE/ WHICH WOULD MEAN THE ACTUAL MAX
SFC TEMPS WILL BE COOLER THAN MODEL FORECASTS. TEMPERATURES AT 925
AND 950 MB WILL BE IN THE 30S...SO EXPECT SURFACE TEMPS NO HIGHER
THAN THE LOWER 40S.

THE SURFACE LOW PRESSURE AREA PASSES WELL NORTH OF NEW ENGLAND
WEDNESDAY AND SWINGS A COLD FRONT THROUGH THE REGION DURING THE
AFTERNOON OR EVENING. MOISTURE CROSS SECTIONS SHOW DECREASING RH IN
THE LIFT AND NUCLEATION ZONES ALOFT WEDNESDAY MORNING...SO THE TREND
THROUGH THE DAY SHOULD BE TO DIMINISHING POPS.

THURSDAY-FRIDAY... THE WEDNESDAY COLD FRONT WILL ALIGN WITH THE
UPPER FLOW AS IT MOVES SOUTH OF NEW ENGLAND...SLOWING ITS OFFSHORE
PROGRESS TO A CRAWL. MEANWHILE WE WILL BE UNDER THE RIGHT ENTRANCE
REGION OF THE SUPPORTING UPPER JET...A SOURCE OF UPPER VENTING. THIS
SHOULD SUPPORT LINGERING CLOUDS AND A CHANCE OF PCPN...WITH TEMPS
SUPPORTIVE OF SNOW. BEST CHANCE SOUTH COAST...LESSER CHANCE FARTHER
NORTH. THE JET AND SURFACE FRONT SWEEP OFFSHORE THURSDAY NIGHT. HIGH
PRESSURE THEN MOVES OVER THE EASTERN USA FOR FRIDAY. TEMPS ALOFT
SUPPORT MAX SFC TEMPS IN THE 20S.

SATURDAY-SUNDAY... ANOTHER NORTHERN STREAM SHORTWAVE AND COLD FRONT
SWINGS THROUGH THE FLOW SATURDAY. CROSS SECTIONS SHOW SOME MOISTURE
ALOFT BUT MOST OF IT IS CONCENTRATED TO OUR NORTH.  ALSO JUST
LIMITED LIFT TO WORK ON THAT MOISTURE. WE WILL HAVE 25-50 PCT SKY
COVER AND NIL POPS. HIGH PRESSURE THEN BUILDS FOR SUNDAY.

&&

.AVIATION /04Z MONDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...

TONIGHT...MODERATE CONFIDENCE. MVFR CIGS WITH PATCHES OF IFR
VALUES. VSBYS MOSTLY 1 TO 3 MILES WITH A ZONE FROM SOUTHERN CT
THROUGH RI AND SE MASS WHERE VSBYS ARE LIFR AT 1/2 MILE TO 1 MILE.
EXPECT THESE CONDITIONS TO LINGER THROUGH MIDNIGHT. THE ZONE OF
LOWER VSBYS AND SNOWFALL RATES COULD WOBBLE NORTH A FEW MILES AND
BRIEFLY APPROACH BOSTON BUT SHOULD PRIMARILY REMAIN TO THE SOUTH.

SOUTH FLOW BRINGS ENOUGH MILDER AIR NORTH TO MIX OR CHANGE THE
PCPN TO RAIN ON NANTUCKET AND PARTS OF THE OUTER CAPE. BULK OF THE
SNOW SHOULD ENDS 06Z WEST TO 10Z EAST /LATE TONIGHT AND EARLY
MONDAY/ MUCH OF THE REGION SHOULD IMPROVE TO VFR CONDITIONS BY
12-13Z MONDAY.

KBOS TAF...CONFIDENT IN OVERALL TRENDS BUT THERE IS UNCERTAINTY ON
TIMING. VSBYS BELOW 1 MILE SHOULD REMAIN TO THE SOUTH BUT COULD
BRIEFLY VISIT THE AIRPORT EARLY TONIGHT. THE BULK OF ACCUMULATING
SNOW IS EXPECTED BY MIDNIGHT.

KBDL TAF...CONFIDENT IN OVERALL TRENDS BUT THERE IS UNCERTAINTY ON
TIMING. BULK OF ACCUMULATING SNOW WITH IFR TO LIFR CONDITIONS
EXPECTED BY MIDNIGHT.

MONDAY AND MONDAY NIGHT...HIGH CONFIDENCE VFR. NORTHWEST WINDS
GUSTING TO 25 TO 30 MPH ACROSS MUCH OF THE AREA DURING MONDAY
AFTERNOON...25 TO 35 MPH GUSTS CAPE/ISLANDS. WINDS DIMINISHING
TOWARDS SUNSET.

OUTLOOK...TUESDAY THROUGH FRIDAY...

TUESDAY...MODERATE CONFIDENCE. VFR DURING THE DAY WITH INCREASING
SKY COVER. MVFR CIGS/VSBYS POSSIBLE LATE IN THE DAY CT RIVER VALLEY.

TUESDAY NIGHT-WEDNESDAY...MODERATE CONFIDENCE. CONDITIONS LOWERING
TO IFR/LIFR. INITIALLY SNOW BUT CHANGING TO SLEET/FREEZING RAIN
DURING THE NIGHT AND RAIN IN THE COASTAL PLAIN OVERNIGHT. PCPN
CHANGES TO RAIN ALL AREAS WEDNESDAY...BUT COLD SURFACES COULD
MAINTAIN A FREEZING RAIN ELEMENT WEDNESDAY MORNING. COLDER AIR MOVES
IN WEDNESDAY NIGHT CHANGING ANY RAIN TO SNOW.

THURSDAY...LOW CONFIDENCE. VFR NORTH OF A HFD-BOS LINE. MVFR CIGS
AND AREAS OF MVFR/IFR VSBYS IN SNOW...DIMINISHING BY EVENING.
NORTHWEST WINDS GUSTING TO 20 KNOTS.

FRIDAY...MODERATE CONFIDENCE. VFR.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...HIGH CONFIDENCE.

A WEAK WAVE OF LOW PRESSURE MOVES ACROSS THE WATERS TONIGHT.
THIS SYSTEM REALLY INTENSIFIES AS IT MOVES INTO THE CANADIAN
MARITIMES NEAR DAYBREAK MONDAY...SO WESTERLY WIND GUSTS MAY REACH
20 TO 25 KNOTS NEAR 12Z MONDAY. OTHERWISE...RAIN AND SNOW THIS
EVENING AND TONIGHT WILL REDUCE VISIBILITIES AT TIMES FOR
MARINERS.

MONDAY...AS THE LOW PRESSURE GOING INTO THE CANADIAN MARITIMES
INTENSIFIES...INCREASING NORTHWEST WINDS ARE EXPECTED OVER THE
SOUTHERN NEW ENGLAND COASTAL WATERS...WITH GALE FORCE GUSTS
EXPECTED. GALE WARNINGS HAVE BEEN HOISTED FOR ALL COASTAL WATERS
FROM MIDDAY MONDAY INTO MONDAY NIGHT.

OUTLOOK...TUESDAY THROUGH FRIDAY..MODERATE CONFIDENCE.

TUESDAY... LINGERING 5 FOOT SEAS SOUTH AND EAST OF NANTUCKET IN THE
MORNING BUT DIMINISHING. NORTHWEST WINDS DIMINISHING FROM 20 KNOTS.
ANY SMALL CRAFT ADVISORY SHOULD END IN THE MORNING.

TUESDAY NIGHT-WEDNESDAY...SOUTH TO SOUTHWEST WINDS WILL INCREASE TO
20-25 KNOTS. SEAS WILL BUILD 6 TO 10 FEET ON THE OUTER WATERS AND ON
RI SOUND. REDUCED VSBYS...INITIALLY SNOW BUT CHANGING TO RAIN. A
SMALL CRAFT ADVISORY MAY BE NEEDED.

THURSDAY...NORTHWEST WIND GUSTING TO 25 KNOTS. SEAS 5 TO 8 FEET
MAINLY ON THE OUTER WATERS...DIMINISHING LATE. A SMALL CRAFT
ADVISORY MAY BE NEEDED.

FRIDAY... SHIFTING WINDS LESS THAN 20 KNOTS. SEAS LESS THAN 5 FEET.
QUIET WEATHER.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WINTER WEATHER ADVISORY UNTIL 4 AM EST MONDAY FOR CTZ002>004.
MA...WINTER STORM WARNING UNTIL 4 AM EST MONDAY FOR MAZ017>021.
     WINTER WEATHER ADVISORY UNTIL 4 AM EST MONDAY FOR MAZ002>016-
     022-023-026.
RI...WINTER STORM WARNING UNTIL 4 AM EST MONDAY FOR RIZ002>008.
     WINTER WEATHER ADVISORY UNTIL 4 AM EST MONDAY FOR RIZ001.
MARINE...GALE WARNING FROM 11 AM MONDAY TO 4 AM EST TUESDAY FOR ANZ231-
     232-250-251-254-255.
     GALE WARNING FROM 11 AM TO 11 PM EST MONDAY FOR ANZ233>235-237-
     256.
     GALE WARNING FROM 11 AM TO 8 PM EST MONDAY FOR ANZ230-236.

&&

$$
SYNOPSIS...WTB/NMB
NEAR TERM...FRANK
SHORT TERM...NMB
LONG TERM...WTB
AVIATION...WTB/NMB
MARINE...WTB/NMB



000
FXUS61 KBOX 020351
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
1050 PM EST SUN MAR 1 2015

.SYNOPSIS...
A FAST MOVING LOW PRESSURE SYSTEM WILL BRING ACCUMULATING SNOW
THIS EVENING AND TONIGHT WITH THE HIGHEST AMOUNTS EXPECTED SOUTH
OF THE MASSACHUSETTS TURNPIKE. HIGH PRESSURE BRINGS DRY COLD AIR
FOR THE EARLY WEEK. LOW PRESSURE FROM NORTHERN CANADA AND
ASSOCIATED LOW FORMING OVER THE PLAINS MONDAY WILL MERGE...THEN
PASS WEST AND NORTH OF NEW ENGLAND. THIS WILL SWING A COLD FRONT
ACROSS THE REGION ON WEDNESDAY. DRY AND COLD WEATHER RETURNS FOR
THE END OF THE WEEK. ANOTHER COLD FRONT MOVES THROUGH ON SATURDAY.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...

1050 PM UPDATE...

BAND OF MODERATE TO HEAVY SNOW CONTINUES TO AFFECT RHODE ISLAND AND
SOUTHEAST MA LATE THIS EVENING.  PTYPE HAS CHANGED TO RAIN AND EVEN
SOME FREEZING RAIN ACROSS THE ISLANDS AND ONTO PORTIONS OF SOUTHERN
MOST CAPE COD.  THAT RAIN/FREEZING RAIN LINE SHOULD NOT MAKE IT TOO
MUCH FURTHER NORTH...BUT MAY AFFECT JUST THE IMMEDIATE SHORELINES
AROUND BUZZARDS BAY AND PORTIONS OF CAPE COD BAY.  MEANWHILE...LIGHT
TO BRIEFLY MODERATE SNOW CONTINUES ACROSS THE REST OF THE REGION AS
A RESULT OF SOME BROAD SCALE LIFT.

OVERALL...EXPECT THE ACCUMULATING SNOW TO BE WINDING DOWN BETWEEN
MIDNIGHT AND 2 AM AS SYSTEM IS QUITE PROGRESSIVE.  TOTAL
ACCUMULATIONS OF 2 TO 4 INCHES NORTH OF THE PIKE AND 3 TO 6 INCHES
SOUTH OF PIKE...WHERE WINTER WEATHER ADVISORIES CONTINUE.  WINTER
STORM WARNING FOR BETWEEN 4 AND 8 INCHES CONTINUES ACROSS MUCH OF
RHODE ISLAND AND SOUTHEAST MA...WHERE WE HAVE HAD A FEW REPORTS UP
TO 6 INCHES ALREADY.  AGAIN...RAIN/SNOW LINE PRETTY MUCH WILL HANG
THE SHORES OF BUZZARDS BAY AND INTO PART OF CAPE COD.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
MONDAY...
PRECIPITATION WILL HAVE LARGELY COME TO AN END FOR DAYBREAK MONDAY
WITH THE LOW PRESSURE RAPIDLY PULLING AWAY INTO THE CANADIAN
MARITIMES AND DRIER AIR/HIGH PRESSURE MOVING IN FROM THE WEST.
INCREASING SUNSHINE EXPECTED DURING THE DAY...WITH TEMPS TOPPING
OUT IN THE UPPER 20S TO MID 30S. HOWEVER AS WE GET TOWARDS
MIDDAY/AFTERNOON TIGHTENING GRADIENT WILL ALLOW NORTHWEST FLOW TO
BECOME BLUSTERY...WITH GUSTS OF 25 TO 30 MPH...25 TO 35 MPH ON THE
CAPE AND ISLANDS.

MONDAY NIGHT...
HIGH PRESSURE SETTLES OVER THE AREA WITH CLEAR SKIES EXPECTED.
GIVEN OUR SNOWPACK IN PLACE AND LIGHT WINDS...SHOULD BE ANOTHER
NIGHT FOR EXCELLENT RADIATIONAL COOLING. BECAUSE OF THIS DID
GENERALLY GO BELOW MODEL GUIDANCE FOR MIN TEMPS...LOOKING TO
ANTICIPATED SURFACE DEWPOINTS FOR A GUIDELINE ON HOW LOW WE CAN
GO. MAY SEE SOME SPOTS IN THE INTERIOR DROP BELOW ZERO.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
BIG PICTURE... THE BROAD UPPER FLOW CONTINUES TO FEATURE A TROUGH
TRANSITING EAST ACROSS THE COUNTRY...REACHING THE EASTERN USA DURING
THE LATE WEEK AND LINGERING THROUGH THE WEEKEND. MEANWHILE AN UPPER
RIDGE SHIFTS FROM THE PACIFIC OCEAN BACK ASHORE ONTO THE WEST COAST.
CONTOUR HEIGHTS IN THE TROUGH ARE LOWEST THURSDAY-FRIDAY AND NEAR
NORMAL OVER THE WEEKEND. THIS MEANS A TREND TO COLDER TEMPS THURSDAY-
FRIDAY FOLLOWED BY A TREND CLOSER TO NORMAL OVER THE WEEKEND.

DAILIES...

TUESDAY... HIGH PRESSURE OVER THE REGION MOVES OFFSHORE BY AFTERNOON
WITH AIRFLOW SWINGING FROM NORTHWEST TO SOUTHWEST. THE SURFACE
AIRMASS STARTS OUT QUITE DRY WITH DEW POINTS IN THE SINGLE NUMBERS
BELOW ZERO TO START...CLIMBING TO 5-10 ABOVE BY EVENING. MODEL CROSS
SECTIONS SHOW INCREASING MOISTURE MORNING AND AFTERNOON ABOVE 700
MB. THIS SUGGESTS INCREASING MID AND HIGH CLOUDS WHILE DRY BENEATH.
LOW LEVEL JETS FROM THE CAROLINAS AND MIDWEST AND THE SURFACE
PRESSURE GRADIENT ALL SUGGEST THE INFLOW AND ISENTROPIC LIFT WILL
REMAIN TO OUR WEST THROUGH THE DAY...POSSIBLY ENTERING WESTERN MA/CT
AT OR AFTER 21Z. SO WE EXPECT INCREASING CLOUDS TUESDAY BUT
OTHERWISE DRY WEATHER THROUGH THE DAY. POSSIBLE LIGHT SNOW AROUND
THE EVENING RUSH HOUR IN THE CT RIVER VALLEY. TEMPS SHOULD REACH THE
MID 20S TO AROUND 30.

TUESDAY NIGHT-WEDNESDAY... NORTHERN AND SOUTHERN STREAM SHORTWAVES
MERGE OVER THE GREAT LAKES AND TRACK INTO CANADA. THIS BRINGS A MILD
FLOW OF AIR UP OVER NEW ENGLAND. THE LEADING EDGE OF THIS AIR
REACHES WESTERN SECTIONS TUESDAY EVENING AND EASTERN SECTIONS
TUESDAY NIGHT. TEMPERATURE PROFILES SUPPORT AN INITIAL PERIOD OF
SNOW CHANGING TO RAIN OR FREEZING RAIN OVERNIGHT. ACTUALLY...THE
MODELS MAY NOT BE HANDLING WELL THE CHILLING MASS OF SNOW AND COLD
GROUND /A.K.A. THE GIANT ICECUBE/ WHICH WOULD MEAN THE ACTUAL MAX
SFC TEMPS WILL BE COOLER THAN MODEL FORECASTS. TEMPERATURES AT 925
AND 950 MB WILL BE IN THE 30S...SO EXPECT SURFACE TEMPS NO HIGHER
THAN THE LOWER 40S.

THE SURFACE LOW PRESSURE AREA PASSES WELL NORTH OF NEW ENGLAND
WEDNESDAY AND SWINGS A COLD FRONT THROUGH THE REGION DURING THE
AFTERNOON OR EVENING. MOISTURE CROSS SECTIONS SHOW DECREASING RH IN
THE LIFT AND NUCLEATION ZONES ALOFT WEDNESDAY MORNING...SO THE TREND
THROUGH THE DAY SHOULD BE TO DIMINISHING POPS.

THURSDAY-FRIDAY... THE WEDNESDAY COLD FRONT WILL ALIGN WITH THE
UPPER FLOW AS IT MOVES SOUTH OF NEW ENGLAND...SLOWING ITS OFFSHORE
PROGRESS TO A CRAWL. MEANWHILE WE WILL BE UNDER THE RIGHT ENTRANCE
REGION OF THE SUPPORTING UPPER JET...A SOURCE OF UPPER VENTING. THIS
SHOULD SUPPORT LINGERING CLOUDS AND A CHANCE OF PCPN...WITH TEMPS
SUPPORTIVE OF SNOW. BEST CHANCE SOUTH COAST...LESSER CHANCE FARTHER
NORTH. THE JET AND SURFACE FRONT SWEEP OFFSHORE THURSDAY NIGHT. HIGH
PRESSURE THEN MOVES OVER THE EASTERN USA FOR FRIDAY. TEMPS ALOFT
SUPPORT MAX SFC TEMPS IN THE 20S.

SATURDAY-SUNDAY... ANOTHER NORTHERN STREAM SHORTWAVE AND COLD FRONT
SWINGS THROUGH THE FLOW SATURDAY. CROSS SECTIONS SHOW SOME MOISTURE
ALOFT BUT MOST OF IT IS CONCENTRATED TO OUR NORTH.  ALSO JUST
LIMITED LIFT TO WORK ON THAT MOISTURE. WE WILL HAVE 25-50 PCT SKY
COVER AND NIL POPS. HIGH PRESSURE THEN BUILDS FOR SUNDAY.

&&

.AVIATION /04Z MONDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...

TONIGHT...MODERATE CONFIDENCE. MVFR CIGS WITH PATCHES OF IFR
VALUES. VSBYS MOSTLY 1 TO 3 MILES WITH A ZONE FROM SOUTHERN CT
THROUGH RI AND SE MASS WHERE VSBYS ARE LIFR AT 1/2 MILE TO 1 MILE.
EXPECT THESE CONDITIONS TO LINGER THROUGH MIDNIGHT. THE ZONE OF
LOWER VSBYS AND SNOWFALL RATES COULD WOBBLE NORTH A FEW MILES AND
BRIEFLY APPROACH BOSTON BUT SHOULD PRIMARILY REMAIN TO THE SOUTH.

SOUTH FLOW BRINGS ENOUGH MILDER AIR NORTH TO MIX OR CHANGE THE
PCPN TO RAIN ON NANTUCKET AND PARTS OF THE OUTER CAPE. BULK OF THE
SNOW SHOULD ENDS 06Z WEST TO 10Z EAST /LATE TONIGHT AND EARLY
MONDAY/ MUCH OF THE REGION SHOULD IMPROVE TO VFR CONDITIONS BY
12-13Z MONDAY.

KBOS TAF...CONFIDENT IN OVERALL TRENDS BUT THERE IS UNCERTAINTY ON
TIMING. VSBYS BELOW 1 MILE SHOULD REMAIN TO THE SOUTH BUT COULD
BRIEFLY VISIT THE AIRPORT EARLY TONIGHT. THE BULK OF ACCUMULATING
SNOW IS EXPECTED BY MIDNIGHT.

KBDL TAF...CONFIDENT IN OVERALL TRENDS BUT THERE IS UNCERTAINTY ON
TIMING. BULK OF ACCUMULATING SNOW WITH IFR TO LIFR CONDITIONS
EXPECTED BY MIDNIGHT.

MONDAY AND MONDAY NIGHT...HIGH CONFIDENCE VFR. NORTHWEST WINDS
GUSTING TO 25 TO 30 MPH ACROSS MUCH OF THE AREA DURING MONDAY
AFTERNOON...25 TO 35 MPH GUSTS CAPE/ISLANDS. WINDS DIMINISHING
TOWARDS SUNSET.

OUTLOOK...TUESDAY THROUGH FRIDAY...

TUESDAY...MODERATE CONFIDENCE. VFR DURING THE DAY WITH INCREASING
SKY COVER. MVFR CIGS/VSBYS POSSIBLE LATE IN THE DAY CT RIVER VALLEY.

TUESDAY NIGHT-WEDNESDAY...MODERATE CONFIDENCE. CONDITIONS LOWERING
TO IFR/LIFR. INITIALLY SNOW BUT CHANGING TO SLEET/FREEZING RAIN
DURING THE NIGHT AND RAIN IN THE COASTAL PLAIN OVERNIGHT. PCPN
CHANGES TO RAIN ALL AREAS WEDNESDAY...BUT COLD SURFACES COULD
MAINTAIN A FREEZING RAIN ELEMENT WEDNESDAY MORNING. COLDER AIR MOVES
IN WEDNESDAY NIGHT CHANGING ANY RAIN TO SNOW.

THURSDAY...LOW CONFIDENCE. VFR NORTH OF A HFD-BOS LINE. MVFR CIGS
AND AREAS OF MVFR/IFR VSBYS IN SNOW...DIMINISHING BY EVENING.
NORTHWEST WINDS GUSTING TO 20 KNOTS.

FRIDAY...MODERATE CONFIDENCE. VFR.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...HIGH CONFIDENCE.

A WEAK WAVE OF LOW PRESSURE MOVES ACROSS THE WATERS TONIGHT.
THIS SYSTEM REALLY INTENSIFIES AS IT MOVES INTO THE CANADIAN
MARITIMES NEAR DAYBREAK MONDAY...SO WESTERLY WIND GUSTS MAY REACH
20 TO 25 KNOTS NEAR 12Z MONDAY. OTHERWISE...RAIN AND SNOW THIS
EVENING AND TONIGHT WILL REDUCE VISIBILITIES AT TIMES FOR
MARINERS.

MONDAY...AS THE LOW PRESSURE GOING INTO THE CANADIAN MARITIMES
INTENSIFIES...INCREASING NORTHWEST WINDS ARE EXPECTED OVER THE
SOUTHERN NEW ENGLAND COASTAL WATERS...WITH GALE FORCE GUSTS
EXPECTED. GALE WARNINGS HAVE BEEN HOISTED FOR ALL COASTAL WATERS
FROM MIDDAY MONDAY INTO MONDAY NIGHT.

OUTLOOK...TUESDAY THROUGH FRIDAY..MODERATE CONFIDENCE.

TUESDAY... LINGERING 5 FOOT SEAS SOUTH AND EAST OF NANTUCKET IN THE
MORNING BUT DIMINISHING. NORTHWEST WINDS DIMINISHING FROM 20 KNOTS.
ANY SMALL CRAFT ADVISORY SHOULD END IN THE MORNING.

TUESDAY NIGHT-WEDNESDAY...SOUTH TO SOUTHWEST WINDS WILL INCREASE TO
20-25 KNOTS. SEAS WILL BUILD 6 TO 10 FEET ON THE OUTER WATERS AND ON
RI SOUND. REDUCED VSBYS...INITIALLY SNOW BUT CHANGING TO RAIN. A
SMALL CRAFT ADVISORY MAY BE NEEDED.

THURSDAY...NORTHWEST WIND GUSTING TO 25 KNOTS. SEAS 5 TO 8 FEET
MAINLY ON THE OUTER WATERS...DIMINISHING LATE. A SMALL CRAFT
ADVISORY MAY BE NEEDED.

FRIDAY... SHIFTING WINDS LESS THAN 20 KNOTS. SEAS LESS THAN 5 FEET.
QUIET WEATHER.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WINTER WEATHER ADVISORY UNTIL 4 AM EST MONDAY FOR CTZ002>004.
MA...WINTER STORM WARNING UNTIL 4 AM EST MONDAY FOR MAZ017>021.
     WINTER WEATHER ADVISORY UNTIL 4 AM EST MONDAY FOR MAZ002>016-
     022-023-026.
RI...WINTER STORM WARNING UNTIL 4 AM EST MONDAY FOR RIZ002>008.
     WINTER WEATHER ADVISORY UNTIL 4 AM EST MONDAY FOR RIZ001.
MARINE...GALE WARNING FROM 11 AM MONDAY TO 4 AM EST TUESDAY FOR ANZ231-
     232-250-251-254-255.
     GALE WARNING FROM 11 AM TO 11 PM EST MONDAY FOR ANZ233>235-237-
     256.
     GALE WARNING FROM 11 AM TO 8 PM EST MONDAY FOR ANZ230-236.

&&

$$
SYNOPSIS...WTB/NMB
NEAR TERM...FRANK
SHORT TERM...NMB
LONG TERM...WTB
AVIATION...WTB/NMB
MARINE...WTB/NMB



000
FXUS61 KBOX 020351
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
1050 PM EST SUN MAR 1 2015

.SYNOPSIS...
A FAST MOVING LOW PRESSURE SYSTEM WILL BRING ACCUMULATING SNOW
THIS EVENING AND TONIGHT WITH THE HIGHEST AMOUNTS EXPECTED SOUTH
OF THE MASSACHUSETTS TURNPIKE. HIGH PRESSURE BRINGS DRY COLD AIR
FOR THE EARLY WEEK. LOW PRESSURE FROM NORTHERN CANADA AND
ASSOCIATED LOW FORMING OVER THE PLAINS MONDAY WILL MERGE...THEN
PASS WEST AND NORTH OF NEW ENGLAND. THIS WILL SWING A COLD FRONT
ACROSS THE REGION ON WEDNESDAY. DRY AND COLD WEATHER RETURNS FOR
THE END OF THE WEEK. ANOTHER COLD FRONT MOVES THROUGH ON SATURDAY.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...

1050 PM UPDATE...

BAND OF MODERATE TO HEAVY SNOW CONTINUES TO AFFECT RHODE ISLAND AND
SOUTHEAST MA LATE THIS EVENING.  PTYPE HAS CHANGED TO RAIN AND EVEN
SOME FREEZING RAIN ACROSS THE ISLANDS AND ONTO PORTIONS OF SOUTHERN
MOST CAPE COD.  THAT RAIN/FREEZING RAIN LINE SHOULD NOT MAKE IT TOO
MUCH FURTHER NORTH...BUT MAY AFFECT JUST THE IMMEDIATE SHORELINES
AROUND BUZZARDS BAY AND PORTIONS OF CAPE COD BAY.  MEANWHILE...LIGHT
TO BRIEFLY MODERATE SNOW CONTINUES ACROSS THE REST OF THE REGION AS
A RESULT OF SOME BROAD SCALE LIFT.

OVERALL...EXPECT THE ACCUMULATING SNOW TO BE WINDING DOWN BETWEEN
MIDNIGHT AND 2 AM AS SYSTEM IS QUITE PROGRESSIVE.  TOTAL
ACCUMULATIONS OF 2 TO 4 INCHES NORTH OF THE PIKE AND 3 TO 6 INCHES
SOUTH OF PIKE...WHERE WINTER WEATHER ADVISORIES CONTINUE.  WINTER
STORM WARNING FOR BETWEEN 4 AND 8 INCHES CONTINUES ACROSS MUCH OF
RHODE ISLAND AND SOUTHEAST MA...WHERE WE HAVE HAD A FEW REPORTS UP
TO 6 INCHES ALREADY.  AGAIN...RAIN/SNOW LINE PRETTY MUCH WILL HANG
THE SHORES OF BUZZARDS BAY AND INTO PART OF CAPE COD.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
MONDAY...
PRECIPITATION WILL HAVE LARGELY COME TO AN END FOR DAYBREAK MONDAY
WITH THE LOW PRESSURE RAPIDLY PULLING AWAY INTO THE CANADIAN
MARITIMES AND DRIER AIR/HIGH PRESSURE MOVING IN FROM THE WEST.
INCREASING SUNSHINE EXPECTED DURING THE DAY...WITH TEMPS TOPPING
OUT IN THE UPPER 20S TO MID 30S. HOWEVER AS WE GET TOWARDS
MIDDAY/AFTERNOON TIGHTENING GRADIENT WILL ALLOW NORTHWEST FLOW TO
BECOME BLUSTERY...WITH GUSTS OF 25 TO 30 MPH...25 TO 35 MPH ON THE
CAPE AND ISLANDS.

MONDAY NIGHT...
HIGH PRESSURE SETTLES OVER THE AREA WITH CLEAR SKIES EXPECTED.
GIVEN OUR SNOWPACK IN PLACE AND LIGHT WINDS...SHOULD BE ANOTHER
NIGHT FOR EXCELLENT RADIATIONAL COOLING. BECAUSE OF THIS DID
GENERALLY GO BELOW MODEL GUIDANCE FOR MIN TEMPS...LOOKING TO
ANTICIPATED SURFACE DEWPOINTS FOR A GUIDELINE ON HOW LOW WE CAN
GO. MAY SEE SOME SPOTS IN THE INTERIOR DROP BELOW ZERO.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
BIG PICTURE... THE BROAD UPPER FLOW CONTINUES TO FEATURE A TROUGH
TRANSITING EAST ACROSS THE COUNTRY...REACHING THE EASTERN USA DURING
THE LATE WEEK AND LINGERING THROUGH THE WEEKEND. MEANWHILE AN UPPER
RIDGE SHIFTS FROM THE PACIFIC OCEAN BACK ASHORE ONTO THE WEST COAST.
CONTOUR HEIGHTS IN THE TROUGH ARE LOWEST THURSDAY-FRIDAY AND NEAR
NORMAL OVER THE WEEKEND. THIS MEANS A TREND TO COLDER TEMPS THURSDAY-
FRIDAY FOLLOWED BY A TREND CLOSER TO NORMAL OVER THE WEEKEND.

DAILIES...

TUESDAY... HIGH PRESSURE OVER THE REGION MOVES OFFSHORE BY AFTERNOON
WITH AIRFLOW SWINGING FROM NORTHWEST TO SOUTHWEST. THE SURFACE
AIRMASS STARTS OUT QUITE DRY WITH DEW POINTS IN THE SINGLE NUMBERS
BELOW ZERO TO START...CLIMBING TO 5-10 ABOVE BY EVENING. MODEL CROSS
SECTIONS SHOW INCREASING MOISTURE MORNING AND AFTERNOON ABOVE 700
MB. THIS SUGGESTS INCREASING MID AND HIGH CLOUDS WHILE DRY BENEATH.
LOW LEVEL JETS FROM THE CAROLINAS AND MIDWEST AND THE SURFACE
PRESSURE GRADIENT ALL SUGGEST THE INFLOW AND ISENTROPIC LIFT WILL
REMAIN TO OUR WEST THROUGH THE DAY...POSSIBLY ENTERING WESTERN MA/CT
AT OR AFTER 21Z. SO WE EXPECT INCREASING CLOUDS TUESDAY BUT
OTHERWISE DRY WEATHER THROUGH THE DAY. POSSIBLE LIGHT SNOW AROUND
THE EVENING RUSH HOUR IN THE CT RIVER VALLEY. TEMPS SHOULD REACH THE
MID 20S TO AROUND 30.

TUESDAY NIGHT-WEDNESDAY... NORTHERN AND SOUTHERN STREAM SHORTWAVES
MERGE OVER THE GREAT LAKES AND TRACK INTO CANADA. THIS BRINGS A MILD
FLOW OF AIR UP OVER NEW ENGLAND. THE LEADING EDGE OF THIS AIR
REACHES WESTERN SECTIONS TUESDAY EVENING AND EASTERN SECTIONS
TUESDAY NIGHT. TEMPERATURE PROFILES SUPPORT AN INITIAL PERIOD OF
SNOW CHANGING TO RAIN OR FREEZING RAIN OVERNIGHT. ACTUALLY...THE
MODELS MAY NOT BE HANDLING WELL THE CHILLING MASS OF SNOW AND COLD
GROUND /A.K.A. THE GIANT ICECUBE/ WHICH WOULD MEAN THE ACTUAL MAX
SFC TEMPS WILL BE COOLER THAN MODEL FORECASTS. TEMPERATURES AT 925
AND 950 MB WILL BE IN THE 30S...SO EXPECT SURFACE TEMPS NO HIGHER
THAN THE LOWER 40S.

THE SURFACE LOW PRESSURE AREA PASSES WELL NORTH OF NEW ENGLAND
WEDNESDAY AND SWINGS A COLD FRONT THROUGH THE REGION DURING THE
AFTERNOON OR EVENING. MOISTURE CROSS SECTIONS SHOW DECREASING RH IN
THE LIFT AND NUCLEATION ZONES ALOFT WEDNESDAY MORNING...SO THE TREND
THROUGH THE DAY SHOULD BE TO DIMINISHING POPS.

THURSDAY-FRIDAY... THE WEDNESDAY COLD FRONT WILL ALIGN WITH THE
UPPER FLOW AS IT MOVES SOUTH OF NEW ENGLAND...SLOWING ITS OFFSHORE
PROGRESS TO A CRAWL. MEANWHILE WE WILL BE UNDER THE RIGHT ENTRANCE
REGION OF THE SUPPORTING UPPER JET...A SOURCE OF UPPER VENTING. THIS
SHOULD SUPPORT LINGERING CLOUDS AND A CHANCE OF PCPN...WITH TEMPS
SUPPORTIVE OF SNOW. BEST CHANCE SOUTH COAST...LESSER CHANCE FARTHER
NORTH. THE JET AND SURFACE FRONT SWEEP OFFSHORE THURSDAY NIGHT. HIGH
PRESSURE THEN MOVES OVER THE EASTERN USA FOR FRIDAY. TEMPS ALOFT
SUPPORT MAX SFC TEMPS IN THE 20S.

SATURDAY-SUNDAY... ANOTHER NORTHERN STREAM SHORTWAVE AND COLD FRONT
SWINGS THROUGH THE FLOW SATURDAY. CROSS SECTIONS SHOW SOME MOISTURE
ALOFT BUT MOST OF IT IS CONCENTRATED TO OUR NORTH.  ALSO JUST
LIMITED LIFT TO WORK ON THAT MOISTURE. WE WILL HAVE 25-50 PCT SKY
COVER AND NIL POPS. HIGH PRESSURE THEN BUILDS FOR SUNDAY.

&&

.AVIATION /04Z MONDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...

TONIGHT...MODERATE CONFIDENCE. MVFR CIGS WITH PATCHES OF IFR
VALUES. VSBYS MOSTLY 1 TO 3 MILES WITH A ZONE FROM SOUTHERN CT
THROUGH RI AND SE MASS WHERE VSBYS ARE LIFR AT 1/2 MILE TO 1 MILE.
EXPECT THESE CONDITIONS TO LINGER THROUGH MIDNIGHT. THE ZONE OF
LOWER VSBYS AND SNOWFALL RATES COULD WOBBLE NORTH A FEW MILES AND
BRIEFLY APPROACH BOSTON BUT SHOULD PRIMARILY REMAIN TO THE SOUTH.

SOUTH FLOW BRINGS ENOUGH MILDER AIR NORTH TO MIX OR CHANGE THE
PCPN TO RAIN ON NANTUCKET AND PARTS OF THE OUTER CAPE. BULK OF THE
SNOW SHOULD ENDS 06Z WEST TO 10Z EAST /LATE TONIGHT AND EARLY
MONDAY/ MUCH OF THE REGION SHOULD IMPROVE TO VFR CONDITIONS BY
12-13Z MONDAY.

KBOS TAF...CONFIDENT IN OVERALL TRENDS BUT THERE IS UNCERTAINTY ON
TIMING. VSBYS BELOW 1 MILE SHOULD REMAIN TO THE SOUTH BUT COULD
BRIEFLY VISIT THE AIRPORT EARLY TONIGHT. THE BULK OF ACCUMULATING
SNOW IS EXPECTED BY MIDNIGHT.

KBDL TAF...CONFIDENT IN OVERALL TRENDS BUT THERE IS UNCERTAINTY ON
TIMING. BULK OF ACCUMULATING SNOW WITH IFR TO LIFR CONDITIONS
EXPECTED BY MIDNIGHT.

MONDAY AND MONDAY NIGHT...HIGH CONFIDENCE VFR. NORTHWEST WINDS
GUSTING TO 25 TO 30 MPH ACROSS MUCH OF THE AREA DURING MONDAY
AFTERNOON...25 TO 35 MPH GUSTS CAPE/ISLANDS. WINDS DIMINISHING
TOWARDS SUNSET.

OUTLOOK...TUESDAY THROUGH FRIDAY...

TUESDAY...MODERATE CONFIDENCE. VFR DURING THE DAY WITH INCREASING
SKY COVER. MVFR CIGS/VSBYS POSSIBLE LATE IN THE DAY CT RIVER VALLEY.

TUESDAY NIGHT-WEDNESDAY...MODERATE CONFIDENCE. CONDITIONS LOWERING
TO IFR/LIFR. INITIALLY SNOW BUT CHANGING TO SLEET/FREEZING RAIN
DURING THE NIGHT AND RAIN IN THE COASTAL PLAIN OVERNIGHT. PCPN
CHANGES TO RAIN ALL AREAS WEDNESDAY...BUT COLD SURFACES COULD
MAINTAIN A FREEZING RAIN ELEMENT WEDNESDAY MORNING. COLDER AIR MOVES
IN WEDNESDAY NIGHT CHANGING ANY RAIN TO SNOW.

THURSDAY...LOW CONFIDENCE. VFR NORTH OF A HFD-BOS LINE. MVFR CIGS
AND AREAS OF MVFR/IFR VSBYS IN SNOW...DIMINISHING BY EVENING.
NORTHWEST WINDS GUSTING TO 20 KNOTS.

FRIDAY...MODERATE CONFIDENCE. VFR.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...HIGH CONFIDENCE.

A WEAK WAVE OF LOW PRESSURE MOVES ACROSS THE WATERS TONIGHT.
THIS SYSTEM REALLY INTENSIFIES AS IT MOVES INTO THE CANADIAN
MARITIMES NEAR DAYBREAK MONDAY...SO WESTERLY WIND GUSTS MAY REACH
20 TO 25 KNOTS NEAR 12Z MONDAY. OTHERWISE...RAIN AND SNOW THIS
EVENING AND TONIGHT WILL REDUCE VISIBILITIES AT TIMES FOR
MARINERS.

MONDAY...AS THE LOW PRESSURE GOING INTO THE CANADIAN MARITIMES
INTENSIFIES...INCREASING NORTHWEST WINDS ARE EXPECTED OVER THE
SOUTHERN NEW ENGLAND COASTAL WATERS...WITH GALE FORCE GUSTS
EXPECTED. GALE WARNINGS HAVE BEEN HOISTED FOR ALL COASTAL WATERS
FROM MIDDAY MONDAY INTO MONDAY NIGHT.

OUTLOOK...TUESDAY THROUGH FRIDAY..MODERATE CONFIDENCE.

TUESDAY... LINGERING 5 FOOT SEAS SOUTH AND EAST OF NANTUCKET IN THE
MORNING BUT DIMINISHING. NORTHWEST WINDS DIMINISHING FROM 20 KNOTS.
ANY SMALL CRAFT ADVISORY SHOULD END IN THE MORNING.

TUESDAY NIGHT-WEDNESDAY...SOUTH TO SOUTHWEST WINDS WILL INCREASE TO
20-25 KNOTS. SEAS WILL BUILD 6 TO 10 FEET ON THE OUTER WATERS AND ON
RI SOUND. REDUCED VSBYS...INITIALLY SNOW BUT CHANGING TO RAIN. A
SMALL CRAFT ADVISORY MAY BE NEEDED.

THURSDAY...NORTHWEST WIND GUSTING TO 25 KNOTS. SEAS 5 TO 8 FEET
MAINLY ON THE OUTER WATERS...DIMINISHING LATE. A SMALL CRAFT
ADVISORY MAY BE NEEDED.

FRIDAY... SHIFTING WINDS LESS THAN 20 KNOTS. SEAS LESS THAN 5 FEET.
QUIET WEATHER.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WINTER WEATHER ADVISORY UNTIL 4 AM EST MONDAY FOR CTZ002>004.
MA...WINTER STORM WARNING UNTIL 4 AM EST MONDAY FOR MAZ017>021.
     WINTER WEATHER ADVISORY UNTIL 4 AM EST MONDAY FOR MAZ002>016-
     022-023-026.
RI...WINTER STORM WARNING UNTIL 4 AM EST MONDAY FOR RIZ002>008.
     WINTER WEATHER ADVISORY UNTIL 4 AM EST MONDAY FOR RIZ001.
MARINE...GALE WARNING FROM 11 AM MONDAY TO 4 AM EST TUESDAY FOR ANZ231-
     232-250-251-254-255.
     GALE WARNING FROM 11 AM TO 11 PM EST MONDAY FOR ANZ233>235-237-
     256.
     GALE WARNING FROM 11 AM TO 8 PM EST MONDAY FOR ANZ230-236.

&&

$$
SYNOPSIS...WTB/NMB
NEAR TERM...FRANK
SHORT TERM...NMB
LONG TERM...WTB
AVIATION...WTB/NMB
MARINE...WTB/NMB



000
FXUS61 KGYX 020227
AFDGYX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
927 PM EST SUN MAR 1 2015

.SYNOPSIS...
LOW PRESSURE WILL MOVE EAST AND CROSS THE REGION OVERNIGHT...PRODUCING
SOME LIGHT SNOW. A STRONG NORTHWEST FLOW WILL SET UP IN ITS WAKE
ON MONDAY. HIGH PRESSURE WILL BUILD IN FROM THE WEST MONDAY NIGHT
AND WILL CREST OVER THE REGION EARLY TUESDAY BEFORE MOVING
OFFSHORE. LOW PRESSURE WILL SWING THROUGH SOUTHERN CANADA TUESDAY
NIGHT PUSHING A WARM FRONT NORTH ACROSS THE REGION...AND PRODUCING
A PERIOD OF SNOW AND MIXED RAIN OR SNOW ALONG THE COAST. AS THE
LOW SHIFTS TO OUR NORTH...IT WILL DRAG A COLD FRONT THROUGH THE
REGION LATE WEDNESDAY. HIGH PRESSURE WILL BUILD IN FROM THE WEST
THURSDAY AND WILL CREST OVER THE REGION ON FRIDAY.

&&

.NEAR TERM /TONIGHT/...
930PM UPDATE...
SNOW IS PROGRESSING ACROSS THE FORECAST AREA THIS EVENING WITH THE
BACK EDGE ALREADY APPEARING IN WESTERN MASSACHUSETTS AND EASTERN
NEW YORK STATE. FEW REPORTS RECEIVED SO FAR HAVE ALL BEEN UNDER 1
INCH. EXPECT STORM TOTALS TO STRUGGLE TO REACH 3 INCHES ALTHOUGH
SOME ENHANCEMENT INLAND OF THE MIDCOAST HAS BEEN NOTED. NO
SIGNIFICANT CHANGES HAVE BEEN MADE TO THE FORECAST.

5PM UPDATE...
HAVE UPDATED PRECIPITATION CHANCES AND SNOWFALL FORECAST OVERNIGHT
AS MORE INTENSE ECHOES NOW SHOWING UP ON RADAR. BEST CHANCE AT
SEEING AN INCH OR TWO WILL BE NEAR THE COAST AND OVER SOUTHERN NEW
HAMPSHIRE WHERE AS MUCH AS 3 INCHES IS POSSIBLE.

ORIGINAL DISCUSSION...
SNOW WILL CONTINUE TO SPREAD EAST THIS EVENING IN ASSOCIATION
WITH BROAD SCALE WARM AIR ADVECTION PATTERN. SOME OF THIS
PRECIPITATION HOWEVER WILL CONTINUE TO SUBLIMATE AS IT INTERACTS
WITH A VERY DRY ATMOSPHERE OVER MAINE AND NEW HAMPSHIRE. EXPECT
PERIODS OF LIGHT SNOW OVERNIGHT. 12Z MODEL SUITE AND MESOSCALE
MODELS HAVE CONTINUED TO BACK OFF ON THE PRECIPITATION FIELDS AND
THEREFORE SNOWFALL AMOUNTS. NEVERTHELESS...THE HIGHEST TOTALS WILL
BE 3-4 INCHES ALONG PORTIONS OF THE MIDCOAST AND OVER FAR SOUTHERN
NH NEAR THE MASSACHUSETTS BORDER. THIS WILL BE JUST BELOW SNOW
ADVISORY CRITERIA.

IT WILL BE A MUCH MILDER NIGHT THAN THOSE OF THE LAST SEVERAL
NIGHTS WITH READINGS BETWEEN 15 AND 25 DEGREES FROM NORTH TO
SOUTH.

&&

.SHORT TERM /MONDAY AND MONDAY NIGHT/...
UPPER LEVEL SUPPORT REMAINS DISJOINTED FROM THE SURFACE
REFLECTION ON MONDAY...WITH THE SHORT WAVE CROSSING LAKE ONTARIO
BY EARLY MONDAY MORNING. THERE COULD BE A PASSING SNOW SHOWER WITH
THIS FEATURE. ACROSS THE NORTHWEST FACING HIGHER TERRAIN...SOME
UPSLOPING PRECIPITATION MAY OCCUR.

AS ARCTIC HIGH BUILDS OVER THE REGION...TEMPERATURES WILL ONCE
AGAIN DROP BELOW ZERO IN NORTHERN AREAS. WIND CHILL VALUES WILL BE
HEADING DOWNWARDS AGAIN AS WELL...BRIEFLY APPROACHING WIND CHILL
ADVISORY LEVELS IN THE MOUNTAINS.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
A SUNNY START ON TUESDAY AS HIGH PRESSURE IS CENTERED OVER THE
REGION. INCREASING HIGH CLOUDS WILL SPILL OVER THE SURFACE/UPPER
RIDGE IN THE AFTERNOON AS THE RIDGE AXIS MOVES OFF TO THE EAST.
TUESDAY NIGHT THE SOUTHWEST FLOW ALOFT WILL ALLOW A SHORT WAVE AND
ASSOCIATED WARM FRONT TO MOVE NORTH INTO NORTHERN NEW ENGLAND WITH
WIDESPREAD WARM AIR ADVECTION SNOW EXPECTED. MID/LOW LEVEL
TEMPERATURES SHOULD ALL BE COLD ENOUGH FOR SNOW EXCEPT ALONG THE
IMMEDIATE COAST WHERE A BRIEF MIX WITH RAIN MAY OCCUR BEFORE
ENDING EARLY WEDNESDAY MORNING. A BLEND OF MODELS QPF SUGGESTS A
SNOWFALL OF 2-6 INCHES EXPECTED. ON WEDNESDAY ALL MODELS INDICATE
THE SNOW TO BE OVER BY EARLY MORNING AND THEN SOME CLEARING AND
TEMPERATURES REACHING INTO THE 40S OVER MOST OF THE AREA AS H85
TEMPERATURES REMAIN MILD INTO THE AFTERNOON COMBINED WITH A
DEVELOPING LIGHT DOWNSLOPING WEST WIND. COLD AIR RETURNS FOR
WEDNESDAY NIGHT AND THURSDAY AS HIGH PRESSURE FROM THE GREAT LAKES
BUILDS EAST AND CONTINUES INTO FRIDAY. TEMPERATURES WILL RETURN TO
BELOW NORMAL FOR THURSDAY AND FRIDAY LIKE A BROKEN RECORD.

&&

.AVIATION /22Z SUNDAY THROUGH FRIDAY/...
SHORT TERM...CEILINGS AND VISIBILITIES GRADUALLY LOWERING AND
DIMINISHING THIS EVENING IN LIGHT SNOW. IFR CONDITIONS EXPECTED IN
MANY AREAS...ESPECIALLY OVER SOUTHERN LOCATIONS.

LONG TERM...
VFR TUESDAY BECOMING IFR TUESDAY NIGHT AND THEN A RETURN TO VFR
CONDITIONS FOR THE MID AND LATTER PART OF THE WEEK.

&&

.MARINE...
SHORT TERM...WILL BE ISSUING GALE WARNINGS FOR MONDAY AFTERNOON
THROUGH MONDAY EVENING FOR THE OUTER WATERS. WINDS WILL JUST TOUCH
GALE FORCE WELL AWAY FROM THE SHORELINE. ALONG THE BAYS...EXPECT
SMALL CRAFT ADVISORY TYPE WINDS INTO TOMORROW EVENING.

LONG TERM...
SCA`S MAY BE NEEDED IN THE SOUTH SOUTHWEST FLOW TUESDAY NIGHT.
THE SCA MAY ALSO BE NEEDED WEDNESDAY NIGHT AND THURSDAY WITH THE
NORTHWEST FLOW.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY FROM NOON TO 11 PM EST MONDAY FOR ANZ151-
     153.
     GALE WARNING FROM NOON TO 11 PM EST MONDAY FOR ANZ150-152-154.

&&

$$

NEAR TERM UPDATE...KIMBLE
SHORT TERM...CANNON
LONG TERM...MARINE
AVIATION...CANNON/MARINE
MARINE...CANNON/MARINE




000
FXUS61 KGYX 020227
AFDGYX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
927 PM EST SUN MAR 1 2015

.SYNOPSIS...
LOW PRESSURE WILL MOVE EAST AND CROSS THE REGION OVERNIGHT...PRODUCING
SOME LIGHT SNOW. A STRONG NORTHWEST FLOW WILL SET UP IN ITS WAKE
ON MONDAY. HIGH PRESSURE WILL BUILD IN FROM THE WEST MONDAY NIGHT
AND WILL CREST OVER THE REGION EARLY TUESDAY BEFORE MOVING
OFFSHORE. LOW PRESSURE WILL SWING THROUGH SOUTHERN CANADA TUESDAY
NIGHT PUSHING A WARM FRONT NORTH ACROSS THE REGION...AND PRODUCING
A PERIOD OF SNOW AND MIXED RAIN OR SNOW ALONG THE COAST. AS THE
LOW SHIFTS TO OUR NORTH...IT WILL DRAG A COLD FRONT THROUGH THE
REGION LATE WEDNESDAY. HIGH PRESSURE WILL BUILD IN FROM THE WEST
THURSDAY AND WILL CREST OVER THE REGION ON FRIDAY.

&&

.NEAR TERM /TONIGHT/...
930PM UPDATE...
SNOW IS PROGRESSING ACROSS THE FORECAST AREA THIS EVENING WITH THE
BACK EDGE ALREADY APPEARING IN WESTERN MASSACHUSETTS AND EASTERN
NEW YORK STATE. FEW REPORTS RECEIVED SO FAR HAVE ALL BEEN UNDER 1
INCH. EXPECT STORM TOTALS TO STRUGGLE TO REACH 3 INCHES ALTHOUGH
SOME ENHANCEMENT INLAND OF THE MIDCOAST HAS BEEN NOTED. NO
SIGNIFICANT CHANGES HAVE BEEN MADE TO THE FORECAST.

5PM UPDATE...
HAVE UPDATED PRECIPITATION CHANCES AND SNOWFALL FORECAST OVERNIGHT
AS MORE INTENSE ECHOES NOW SHOWING UP ON RADAR. BEST CHANCE AT
SEEING AN INCH OR TWO WILL BE NEAR THE COAST AND OVER SOUTHERN NEW
HAMPSHIRE WHERE AS MUCH AS 3 INCHES IS POSSIBLE.

ORIGINAL DISCUSSION...
SNOW WILL CONTINUE TO SPREAD EAST THIS EVENING IN ASSOCIATION
WITH BROAD SCALE WARM AIR ADVECTION PATTERN. SOME OF THIS
PRECIPITATION HOWEVER WILL CONTINUE TO SUBLIMATE AS IT INTERACTS
WITH A VERY DRY ATMOSPHERE OVER MAINE AND NEW HAMPSHIRE. EXPECT
PERIODS OF LIGHT SNOW OVERNIGHT. 12Z MODEL SUITE AND MESOSCALE
MODELS HAVE CONTINUED TO BACK OFF ON THE PRECIPITATION FIELDS AND
THEREFORE SNOWFALL AMOUNTS. NEVERTHELESS...THE HIGHEST TOTALS WILL
BE 3-4 INCHES ALONG PORTIONS OF THE MIDCOAST AND OVER FAR SOUTHERN
NH NEAR THE MASSACHUSETTS BORDER. THIS WILL BE JUST BELOW SNOW
ADVISORY CRITERIA.

IT WILL BE A MUCH MILDER NIGHT THAN THOSE OF THE LAST SEVERAL
NIGHTS WITH READINGS BETWEEN 15 AND 25 DEGREES FROM NORTH TO
SOUTH.

&&

.SHORT TERM /MONDAY AND MONDAY NIGHT/...
UPPER LEVEL SUPPORT REMAINS DISJOINTED FROM THE SURFACE
REFLECTION ON MONDAY...WITH THE SHORT WAVE CROSSING LAKE ONTARIO
BY EARLY MONDAY MORNING. THERE COULD BE A PASSING SNOW SHOWER WITH
THIS FEATURE. ACROSS THE NORTHWEST FACING HIGHER TERRAIN...SOME
UPSLOPING PRECIPITATION MAY OCCUR.

AS ARCTIC HIGH BUILDS OVER THE REGION...TEMPERATURES WILL ONCE
AGAIN DROP BELOW ZERO IN NORTHERN AREAS. WIND CHILL VALUES WILL BE
HEADING DOWNWARDS AGAIN AS WELL...BRIEFLY APPROACHING WIND CHILL
ADVISORY LEVELS IN THE MOUNTAINS.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
A SUNNY START ON TUESDAY AS HIGH PRESSURE IS CENTERED OVER THE
REGION. INCREASING HIGH CLOUDS WILL SPILL OVER THE SURFACE/UPPER
RIDGE IN THE AFTERNOON AS THE RIDGE AXIS MOVES OFF TO THE EAST.
TUESDAY NIGHT THE SOUTHWEST FLOW ALOFT WILL ALLOW A SHORT WAVE AND
ASSOCIATED WARM FRONT TO MOVE NORTH INTO NORTHERN NEW ENGLAND WITH
WIDESPREAD WARM AIR ADVECTION SNOW EXPECTED. MID/LOW LEVEL
TEMPERATURES SHOULD ALL BE COLD ENOUGH FOR SNOW EXCEPT ALONG THE
IMMEDIATE COAST WHERE A BRIEF MIX WITH RAIN MAY OCCUR BEFORE
ENDING EARLY WEDNESDAY MORNING. A BLEND OF MODELS QPF SUGGESTS A
SNOWFALL OF 2-6 INCHES EXPECTED. ON WEDNESDAY ALL MODELS INDICATE
THE SNOW TO BE OVER BY EARLY MORNING AND THEN SOME CLEARING AND
TEMPERATURES REACHING INTO THE 40S OVER MOST OF THE AREA AS H85
TEMPERATURES REMAIN MILD INTO THE AFTERNOON COMBINED WITH A
DEVELOPING LIGHT DOWNSLOPING WEST WIND. COLD AIR RETURNS FOR
WEDNESDAY NIGHT AND THURSDAY AS HIGH PRESSURE FROM THE GREAT LAKES
BUILDS EAST AND CONTINUES INTO FRIDAY. TEMPERATURES WILL RETURN TO
BELOW NORMAL FOR THURSDAY AND FRIDAY LIKE A BROKEN RECORD.

&&

.AVIATION /22Z SUNDAY THROUGH FRIDAY/...
SHORT TERM...CEILINGS AND VISIBILITIES GRADUALLY LOWERING AND
DIMINISHING THIS EVENING IN LIGHT SNOW. IFR CONDITIONS EXPECTED IN
MANY AREAS...ESPECIALLY OVER SOUTHERN LOCATIONS.

LONG TERM...
VFR TUESDAY BECOMING IFR TUESDAY NIGHT AND THEN A RETURN TO VFR
CONDITIONS FOR THE MID AND LATTER PART OF THE WEEK.

&&

.MARINE...
SHORT TERM...WILL BE ISSUING GALE WARNINGS FOR MONDAY AFTERNOON
THROUGH MONDAY EVENING FOR THE OUTER WATERS. WINDS WILL JUST TOUCH
GALE FORCE WELL AWAY FROM THE SHORELINE. ALONG THE BAYS...EXPECT
SMALL CRAFT ADVISORY TYPE WINDS INTO TOMORROW EVENING.

LONG TERM...
SCA`S MAY BE NEEDED IN THE SOUTH SOUTHWEST FLOW TUESDAY NIGHT.
THE SCA MAY ALSO BE NEEDED WEDNESDAY NIGHT AND THURSDAY WITH THE
NORTHWEST FLOW.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY FROM NOON TO 11 PM EST MONDAY FOR ANZ151-
     153.
     GALE WARNING FROM NOON TO 11 PM EST MONDAY FOR ANZ150-152-154.

&&

$$

NEAR TERM UPDATE...KIMBLE
SHORT TERM...CANNON
LONG TERM...MARINE
AVIATION...CANNON/MARINE
MARINE...CANNON/MARINE



000
FXUS61 KBOX 020202
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
902 PM EST SUN MAR 1 2015

.SYNOPSIS...

A FAST MOVING LOW PRESSURE SYSTEM WILL BRING ACCUMULATING SNOW
THIS EVENING AND TONIGHT WITH THE HIGHEST AMOUNTS EXPECTED SOUTH
OF THE MASSACHUSETTS TURNPIKE. HIGH PRESSURE BRINGS DRY COLD AIR
FOR THE EARLY WEEK. LOW PRESSURE FROM NORTHERN CANADA AND
ASSOCIATED LOW FORMING OVER THE PLAINS MONDAY WILL MERGE...THEN
PASS WEST AND NORTH OF NEW ENGLAND. THIS WILL SWING A COLD FRONT
ACROSS THE REGION ON WEDNESDAY. DRY AND COLD WEATHER RETURNS FOR
THE END OF THE WEEK. ANOTHER COLD FRONT MOVES THROUGH ON SATURDAY.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...

9 PM UPDATE...

WIDESPREAD LIGHT TO MODERATE SNOW WAS AFFECTING ALL OF SOUTHERN NEW
ENGLAND THIS EVENING AS RESULT OF BROAD SCALE MID LEVEL LIFT.  THERE
WAS BAND OF MODERATE TO HEAVY SNOW ACROSS SOUTHERN RI AND SOUTHEAST
MA.  THIS A RESULT OF BETTER FORCING/MOISTURE WITH A STRONGER LOW
LEVEL JET IMPINGING ON THAT REGION.  SURFACE WINDS WERE VERY LIGHT
FROM THE SOUTH OR EVEN CALM ALONG THE SOUTH COAST...WHICH IS LIKELY
AIDING IN SOME LOW LEVEL CONVERGENCE.

NOT TOO MANY CHANGES NEEDED TO THE FORECAST THIS EVENING.  BASED ON
THE LATEST DATA...PROBABLY REMAINS PRETTY MUCH ALL SNOW EVEN FOR
MOST OF CAPE COD.  PERHAPS A BRIEF CHANGE OVER AT THE END NEAR
CHATHAM AT THE END...BUT A WIDESPREAD 3 TO 6 INCHES OF SNOW
EXPECTED.  IT MIGHT END UP CLOSE TO A MARGINAL WARNING ACROSS THE
UPPER CAPE...BUT NOT ENOUGH CONFIDENCE TO PULL THE TRIGGER.
NANTUCKET HAS JUST CHANGED TO RAIN AND PROBABLY WILL SEE MARTHAS
VINEYARD GO OVER IN THE NEXT FEW HOURS.

OTHERWISE...LOOKS LIKE 2 TO 4 INCHES NORTH OF THE PIKE...3 TO 6
INCHES SOUTH OF THE PIKE.  STILL EXPECT A SWATH OF 4 TO 8 INCHES
ACROSS PORTIONS OF RHODE ISLAND AND SOUTHEAST MA WITH THE HELP OF
THE LOW LEVEL JET AND WILL BE CONTINUING THE WINTER STORM WARNING
FOR THAT REGION.

LATEST MODELS DATA IN FAIRLY GOOD AGREEMENT THAT ALL BULK OF THE
ACCUMULATIONS SNOW WINDS DOWN FROM WEST TO EAST BETWEEN 11 PM AND 1
OR 2 AM...BUT MAY LINGER A BIT LONGER ACROSS THE CAPE/ISLANDS.

PREVIOUS DISCUSSION:

LOW PRESSURE EMERGING FROM THE MID ATLANTIC COASTLINE IS EXPECTED
TO PASS SOUTHEAST OF NANTUCKET TONIGHT...BRINGING A WIDESPREAD
SNOW TO SOUTHERN NEW ENGLAND. SURFACE OBS AS OF 21Z INDICATE THAT
SNOW HAS OVERSPREAD THE ENTIRE AREA. THE STRONGEST RADAR
RETURNS AT 21Z WERE NEAR THE SOUTH COAST OF CT INTO RI...AND TO
THE SOUTHWEST. THE BETTER FORCING FROM THIS EVENT IS EXPECTED TO OCCUR
TO THE SOUTH OF THE MA TURNPIKE. 12Z MODELS WERE IN DECENT
AGREEMENT ON PLACING THE HIGHEST QPF IN THAT AREA.

BECAUSE OF THE QUICK HITTING NATURE OF THIS SYSTEM WITH A SHORT
LIVED WINDOW FOR VERY STRONG LIFT/FORCING...CONTINUE TO THINK THAT
FOR MOST OF THE REGION WINTER WEATHER ADVISORY/S FOR 3 TO 6 INCHES
OF SNOW WILL COVER THIS EVENT. HOWEVER...GIVEN THERE IS NICE
OMEGA IN THE SNOW GROWTH REGION...WE MIGHT BE LOOKING AT SOME
DECENT RATIOS. SO WE STILL CAN NOT RULE OUT THE LOW RISK OF
REACHING WARNING AMOUNTS...ESPECIALLY ACROSS NORTHERN CT AND
NORTHWEST RI.

WE DID UPGRADED BLOCK ISLAND TO A WINTER STORM WARNING FOR THE
LATE AFTERNOON FORECAST PACKAGE. THERE MAY BE SOME MIXING WITH
RAIN IN THIS AREA AT TIMES.

EXPECT THIS TO BE A SNOW EVENT FOR THE VAST MAJORITY OF SOUTHERN
NEW ENGLAND. IT DOES BECOME A VERY CLOSE CALL NEAR THE SOUTH
COAST...BUT WERE LEANING TOWARDS IT STAYING MAINLY WET SNOW.
CONTINUED THE HIGH END WINTER WEATHER ADVISORY FOR THE CAPE
BECAUSE THEY MAY CHANGE TO RAIN FOR A TIME...ESPECIALLY EAST OF
HYANNIS. IF THE CHANGE OVER DOES NOT OCCUR...SNOWFALL TOTALS MAY
BE SOMEWHAT HIGHER. THE PRECIPITATION IS EXPECTED TO COME TO AN
END ACROSS THE MAJORITY OF THE AREA BY DAYBREAK MONDAY.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
MONDAY...
PRECIPITATION WILL HAVE LARGELY COME TO AN END FOR DAYBREAK MONDAY
WITH THE LOW PRESSURE RAPIDLY PULLING AWAY INTO THE CANADIAN
MARITIMES AND DRIER AIR/HIGH PRESSURE MOVING IN FROM THE WEST.
INCREASING SUNSHINE EXPECTED DURING THE DAY...WITH TEMPS TOPPING
OUT IN THE UPPER 20S TO MID 30S. HOWEVER AS WE GET TOWARDS
MIDDAY/AFTERNOON TIGHTENING GRADIENT WILL ALLOW NORTHWEST FLOW TO
BECOME BLUSTERY...WITH GUSTS OF 25 TO 30 MPH...25 TO 35 MPH ON THE
CAPE AND ISLANDS.

MONDAY NIGHT...
HIGH PRESSURE SETTLES OVER THE AREA WITH CLEAR SKIES EXPECTED.
GIVEN OUR SNOWPACK IN PLACE AND LIGHT WINDS...SHOULD BE ANOTHER
NIGHT FOR EXCELLENT RADIATIONAL COOLING. BECAUSE OF THIS DID
GENERALLY GO BELOW MODEL GUIDANCE FOR MIN TEMPS...LOOKING TO
ANTICIPATED SURFACE DEWPOINTS FOR A GUIDELINE ON HOW LOW WE CAN
GO. MAY SEE SOME SPOTS IN THE INTERIOR DROP BELOW ZERO.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
BIG PICTURE... THE BROAD UPPER FLOW CONTINUES TO FEATURE A TROUGH
TRANSITING EAST ACROSS THE COUNTRY...REACHING THE EASTERN USA DURING
THE LATE WEEK AND LINGERING THROUGH THE WEEKEND. MEANWHILE AN UPPER
RIDGE SHIFTS FROM THE PACIFIC OCEAN BACK ASHORE ONTO THE WEST COAST.
CONTOUR HEIGHTS IN THE TROUGH ARE LOWEST THURSDAY-FRIDAY AND NEAR
NORMAL OVER THE WEEKEND. THIS MEANS A TREND TO COLDER TEMPS THURSDAY-
FRIDAY FOLLOWED BY A TREND CLOSER TO NORMAL OVER THE WEEKEND.

DAILIES...

TUESDAY... HIGH PRESSURE OVER THE REGION MOVES OFFSHORE BY AFTERNOON
WITH AIRFLOW SWINGING FROM NORTHWEST TO SOUTHWEST. THE SURFACE
AIRMASS STARTS OUT QUITE DRY WITH DEW POINTS IN THE SINGLE NUMBERS
BELOW ZERO TO START...CLIMBING TO 5-10 ABOVE BY EVENING. MODEL CROSS
SECTIONS SHOW INCREASING MOISTURE MORNING AND AFTERNOON ABOVE 700
MB. THIS SUGGESTS INCREASING MID AND HIGH CLOUDS WHILE DRY BENEATH.
LOW LEVEL JETS FROM THE CAROLINAS AND MIDWEST AND THE SURFACE
PRESSURE GRADIENT ALL SUGGEST THE INFLOW AND ISENTROPIC LIFT WILL
REMAIN TO OUR WEST THROUGH THE DAY...POSSIBLY ENTERING WESTERN MA/CT
AT OR AFTER 21Z. SO WE EXPECT INCREASING CLOUDS TUESDAY BUT
OTHERWISE DRY WEATHER THROUGH THE DAY. POSSIBLE LIGHT SNOW AROUND
THE EVENING RUSH HOUR IN THE CT RIVER VALLEY. TEMPS SHOULD REACH THE
MID 20S TO AROUND 30.

TUESDAY NIGHT-WEDNESDAY... NORTHERN AND SOUTHERN STREAM SHORTWAVES
MERGE OVER THE GREAT LAKES AND TRACK INTO CANADA. THIS BRINGS A MILD
FLOW OF AIR UP OVER NEW ENGLAND. THE LEADING EDGE OF THIS AIR
REACHES WESTERN SECTIONS TUESDAY EVENING AND EASTERN SECTIONS
TUESDAY NIGHT. TEMPERATURE PROFILES SUPPORT AN INITIAL PERIOD OF
SNOW CHANGING TO RAIN OR FREEZING RAIN OVERNIGHT. ACTUALLY...THE
MODELS MAY NOT BE HANDLING WELL THE CHILLING MASS OF SNOW AND COLD
GROUND /A.K.A. THE GIANT ICECUBE/ WHICH WOULD MEAN THE ACTUAL MAX
SFC TEMPS WILL BE COOLER THAN MODEL FORECASTS. TEMPERATURES AT 925
AND 950 MB WILL BE IN THE 30S...SO EXPECT SURFACE TEMPS NO HIGHER
THAN THE LOWER 40S.

THE SURFACE LOW PRESSURE AREA PASSES WELL NORTH OF NEW ENGLAND
WEDNESDAY AND SWINGS A COLD FRONT THROUGH THE REGION DURING THE
AFTERNOON OR EVENING. MOISTURE CROSS SECTIONS SHOW DECREASING RH IN
THE LIFT AND NUCLEATION ZONES ALOFT WEDNESDAY MORNING...SO THE TREND
THROUGH THE DAY SHOULD BE TO DIMINISHING POPS.

THURSDAY-FRIDAY... THE WEDNESDAY COLD FRONT WILL ALIGN WITH THE
UPPER FLOW AS IT MOVES SOUTH OF NEW ENGLAND...SLOWING ITS OFFSHORE
PROGRESS TO A CRAWL. MEANWHILE WE WILL BE UNDER THE RIGHT ENTRANCE
REGION OF THE SUPPORTING UPPER JET...A SOURCE OF UPPER VENTING. THIS
SHOULD SUPPORT LINGERING CLOUDS AND A CHANCE OF PCPN...WITH TEMPS
SUPPORTIVE OF SNOW. BEST CHANCE SOUTH COAST...LESSER CHANCE FARTHER
NORTH. THE JET AND SURFACE FRONT SWEEP OFFSHORE THURSDAY NIGHT. HIGH
PRESSURE THEN MOVES OVER THE EASTERN USA FOR FRIDAY. TEMPS ALOFT
SUPPORT MAX SFC TEMPS IN THE 20S.

SATURDAY-SUNDAY... ANOTHER NORTHERN STREAM SHORTWAVE AND COLD FRONT
SWINGS THROUGH THE FLOW SATURDAY. CROSS SECTIONS SHOW SOME MOISTURE
ALOFT BUT MOST OF IT IS CONCENTRATED TO OUR NORTH.  ALSO JUST
LIMITED LIFT TO WORK ON THAT MOISTURE. WE WILL HAVE 25-50 PCT SKY
COVER AND NIL POPS. HIGH PRESSURE THEN BUILDS FOR SUNDAY.

&&

.AVIATION /02Z MONDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...

TONIGHT...MODERATE CONFIDENCE. MVFR CIGS WITH PATCHES OF IFR
VALUES. VSBYS MOSTLY 1 TO 3 MILES WITH A ZONE FROM SOUTHERN CT
THROUGH RI AND SE MASS WHERE VSBYS ARE LIFR AT 1/2 MILE TO 1 MILE.
EXPECT THESE CONDITIONS TO LINGER THROUGH MIDNIGHT. THE ZONE OF
LOWER VSBYS AND SNOWFALL RATES COULD WOBBLE NORTH A FEW MILES AND
BRIEFLY APPROACH BOSTON BUT SHOULD PRIMARILY REMAIN TO THE SOUTH.

SOUTH FLOW BRINGS ENOUGH MILDER AIR NORTH TO MIX OR CHANGE THE
PCPN TO RAIN ON NANTUCKET AND PARTS OF THE OUTER CAPE. BULK OF THE
SNOW SHOULD ENDS 06Z WEST TO 10Z EAST /LATE TONIGHT AND EARLY
MONDAY/ MUCH OF THE REGION SHOULD IMPROVE TO VFR CONDITIONS BY
12-13Z MONDAY.

KBOS TAF...CONFIDENT IN OVERALL TRENDS BUT THERE IS UNCERTAINTY ON
TIMING. VSBYS BELOW 1 MILE SHOULD REMAIN TO THE SOUTH BUT COULD
BRIEFLY VISIT THE AIRPORT EARLY TONIGHT. THE BULK OF ACCUMULATING
SNOW IS EXPECTED BY MIDNIGHT.

KBDL TAF...CONFIDENT IN OVERALL TRENDS BUT THERE IS UNCERTAINTY ON
TIMING. BULK OF ACCUMULATING SNOW WITH IFR TO LIFR CONDITIONS
EXPECTED BY MIDNIGHT.

MONDAY AND MONDAY NIGHT...HIGH CONFIDENCE VFR. NORTHWEST WINDS
GUSTING TO 25 TO 30 MPH ACROSS MUCH OF THE AREA DURING MONDAY
AFTERNOON...25 TO 35 MPH GUSTS CAPE/ISLANDS. WINDS DIMINISHING
TOWARDS SUNSET.

OUTLOOK...TUESDAY THROUGH FRIDAY...

TUESDAY...MODERATE CONFIDENCE. VFR DURING THE DAY WITH INCREASING
SKY COVER. MVFR CIGS/VSBYS POSSIBLE LATE IN THE DAY CT RIVER VALLEY.

TUESDAY NIGHT-WEDNESDAY...MODERATE CONFIDENCE. CONDITIONS LOWERING
TO IFR/LIFR. INITIALLY SNOW BUT CHANGING TO SLEET/FREEZING RAIN
DURING THE NIGHT AND RAIN IN THE COASTAL PLAIN OVERNIGHT. PCPN
CHANGES TO RAIN ALL AREAS WEDNESDAY...BUT COLD SURFACES COULD
MAINTAIN A FREEZING RAIN ELEMENT WEDNESDAY MORNING. COLDER AIR MOVES
IN WEDNESDAY NIGHT CHANGING ANY RAIN TO SNOW.

THURSDAY...LOW CONFIDENCE. VFR NORTH OF A HFD-BOS LINE. MVFR CIGS
AND AREAS OF MVFR/IFR VSBYS IN SNOW...DIMINISHING BY EVENING.
NORTHWEST WINDS GUSTING TO 20 KNOTS.

FRIDAY...MODERATE CONFIDENCE. VFR.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...HIGH CONFIDENCE.

A WEAK WAVE OF LOW PRESSURE MOVES ACROSS THE WATERS TONIGHT.
THIS SYSTEM REALLY INTENSIFIES AS IT MOVES INTO THE CANADIAN
MARITIMES NEAR DAYBREAK MONDAY...SO WESTERLY WIND GUSTS MAY REACH
20 TO 25 KNOTS NEAR 12Z MONDAY. OTHERWISE...RAIN AND SNOW THIS
EVENING AND TONIGHT WILL REDUCE VISIBILITIES AT TIMES FOR
MARINERS.

MONDAY...AS THE LOW PRESSURE GOING INTO THE CANADIAN MARITIMES
INTENSIFIES...INCREASING NORTHWEST WINDS ARE EXPECTED OVER THE
SOUTHERN NEW ENGLAND COASTAL WATERS...WITH GALE FORCE GUSTS
EXPECTED. GALE WARNINGS HAVE BEEN HOISTED FOR ALL COASTAL WATERS
FROM MIDDAY MONDAY INTO MONDAY NIGHT.

OUTLOOK...TUESDAY THROUGH FRIDAY..MODERATE CONFIDENCE.

TUESDAY... LINGERING 5 FOOT SEAS SOUTH AND EAST OF NANTUCKET IN THE
MORNING BUT DIMINISHING. NORTHWEST WINDS DIMINISHING FROM 20 KNOTS.
ANY SMALL CRAFT ADVISORY SHOULD END IN THE MORNING.

TUESDAY NIGHT-WEDNESDAY...SOUTH TO SOUTHWEST WINDS WILL INCREASE TO
20-25 KNOTS. SEAS WILL BUILD 6 TO 10 FEET ON THE OUTER WATERS AND ON
RI SOUND. REDUCED VSBYS...INITIALLY SNOW BUT CHANGING TO RAIN. A
SMALL CRAFT ADVISORY MAY BE NEEDED.

THURSDAY...NORTHWEST WIND GUSTING TO 25 KNOTS. SEAS 5 TO 8 FEET
MAINLY ON THE OUTER WATERS...DIMINISHING LATE. A SMALL CRAFT
ADVISORY MAY BE NEEDED.

FRIDAY... SHIFTING WINDS LESS THAN 20 KNOTS. SEAS LESS THAN 5 FEET.
QUIET WEATHER.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR CTZ002>004.
MA...WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR MAZ017>021.
     WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR MAZ002>016-
     022>024-026.
RI...WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR RIZ002>008.
     WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR RIZ001.
MARINE...GALE WARNING FROM 11 AM MONDAY TO 4 AM EST TUESDAY FOR ANZ231-
     232-250-251-254-255.
     GALE WARNING FROM 11 AM TO 11 PM EST MONDAY FOR ANZ233>235-237-
     256.
     GALE WARNING FROM 11 AM TO 8 PM EST MONDAY FOR ANZ230-236.

&&

$$
SYNOPSIS...WTB/NMB
NEAR TERM...FRANK/NMB
SHORT TERM...NMB
LONG TERM...WTB
AVIATION...WTB/NMB
MARINE...WTB/NMB




000
FXUS61 KBOX 020202
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
902 PM EST SUN MAR 1 2015

.SYNOPSIS...

A FAST MOVING LOW PRESSURE SYSTEM WILL BRING ACCUMULATING SNOW
THIS EVENING AND TONIGHT WITH THE HIGHEST AMOUNTS EXPECTED SOUTH
OF THE MASSACHUSETTS TURNPIKE. HIGH PRESSURE BRINGS DRY COLD AIR
FOR THE EARLY WEEK. LOW PRESSURE FROM NORTHERN CANADA AND
ASSOCIATED LOW FORMING OVER THE PLAINS MONDAY WILL MERGE...THEN
PASS WEST AND NORTH OF NEW ENGLAND. THIS WILL SWING A COLD FRONT
ACROSS THE REGION ON WEDNESDAY. DRY AND COLD WEATHER RETURNS FOR
THE END OF THE WEEK. ANOTHER COLD FRONT MOVES THROUGH ON SATURDAY.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...

9 PM UPDATE...

WIDESPREAD LIGHT TO MODERATE SNOW WAS AFFECTING ALL OF SOUTHERN NEW
ENGLAND THIS EVENING AS RESULT OF BROAD SCALE MID LEVEL LIFT.  THERE
WAS BAND OF MODERATE TO HEAVY SNOW ACROSS SOUTHERN RI AND SOUTHEAST
MA.  THIS A RESULT OF BETTER FORCING/MOISTURE WITH A STRONGER LOW
LEVEL JET IMPINGING ON THAT REGION.  SURFACE WINDS WERE VERY LIGHT
FROM THE SOUTH OR EVEN CALM ALONG THE SOUTH COAST...WHICH IS LIKELY
AIDING IN SOME LOW LEVEL CONVERGENCE.

NOT TOO MANY CHANGES NEEDED TO THE FORECAST THIS EVENING.  BASED ON
THE LATEST DATA...PROBABLY REMAINS PRETTY MUCH ALL SNOW EVEN FOR
MOST OF CAPE COD.  PERHAPS A BRIEF CHANGE OVER AT THE END NEAR
CHATHAM AT THE END...BUT A WIDESPREAD 3 TO 6 INCHES OF SNOW
EXPECTED.  IT MIGHT END UP CLOSE TO A MARGINAL WARNING ACROSS THE
UPPER CAPE...BUT NOT ENOUGH CONFIDENCE TO PULL THE TRIGGER.
NANTUCKET HAS JUST CHANGED TO RAIN AND PROBABLY WILL SEE MARTHAS
VINEYARD GO OVER IN THE NEXT FEW HOURS.

OTHERWISE...LOOKS LIKE 2 TO 4 INCHES NORTH OF THE PIKE...3 TO 6
INCHES SOUTH OF THE PIKE.  STILL EXPECT A SWATH OF 4 TO 8 INCHES
ACROSS PORTIONS OF RHODE ISLAND AND SOUTHEAST MA WITH THE HELP OF
THE LOW LEVEL JET AND WILL BE CONTINUING THE WINTER STORM WARNING
FOR THAT REGION.

LATEST MODELS DATA IN FAIRLY GOOD AGREEMENT THAT ALL BULK OF THE
ACCUMULATIONS SNOW WINDS DOWN FROM WEST TO EAST BETWEEN 11 PM AND 1
OR 2 AM...BUT MAY LINGER A BIT LONGER ACROSS THE CAPE/ISLANDS.

PREVIOUS DISCUSSION:

LOW PRESSURE EMERGING FROM THE MID ATLANTIC COASTLINE IS EXPECTED
TO PASS SOUTHEAST OF NANTUCKET TONIGHT...BRINGING A WIDESPREAD
SNOW TO SOUTHERN NEW ENGLAND. SURFACE OBS AS OF 21Z INDICATE THAT
SNOW HAS OVERSPREAD THE ENTIRE AREA. THE STRONGEST RADAR
RETURNS AT 21Z WERE NEAR THE SOUTH COAST OF CT INTO RI...AND TO
THE SOUTHWEST. THE BETTER FORCING FROM THIS EVENT IS EXPECTED TO OCCUR
TO THE SOUTH OF THE MA TURNPIKE. 12Z MODELS WERE IN DECENT
AGREEMENT ON PLACING THE HIGHEST QPF IN THAT AREA.

BECAUSE OF THE QUICK HITTING NATURE OF THIS SYSTEM WITH A SHORT
LIVED WINDOW FOR VERY STRONG LIFT/FORCING...CONTINUE TO THINK THAT
FOR MOST OF THE REGION WINTER WEATHER ADVISORY/S FOR 3 TO 6 INCHES
OF SNOW WILL COVER THIS EVENT. HOWEVER...GIVEN THERE IS NICE
OMEGA IN THE SNOW GROWTH REGION...WE MIGHT BE LOOKING AT SOME
DECENT RATIOS. SO WE STILL CAN NOT RULE OUT THE LOW RISK OF
REACHING WARNING AMOUNTS...ESPECIALLY ACROSS NORTHERN CT AND
NORTHWEST RI.

WE DID UPGRADED BLOCK ISLAND TO A WINTER STORM WARNING FOR THE
LATE AFTERNOON FORECAST PACKAGE. THERE MAY BE SOME MIXING WITH
RAIN IN THIS AREA AT TIMES.

EXPECT THIS TO BE A SNOW EVENT FOR THE VAST MAJORITY OF SOUTHERN
NEW ENGLAND. IT DOES BECOME A VERY CLOSE CALL NEAR THE SOUTH
COAST...BUT WERE LEANING TOWARDS IT STAYING MAINLY WET SNOW.
CONTINUED THE HIGH END WINTER WEATHER ADVISORY FOR THE CAPE
BECAUSE THEY MAY CHANGE TO RAIN FOR A TIME...ESPECIALLY EAST OF
HYANNIS. IF THE CHANGE OVER DOES NOT OCCUR...SNOWFALL TOTALS MAY
BE SOMEWHAT HIGHER. THE PRECIPITATION IS EXPECTED TO COME TO AN
END ACROSS THE MAJORITY OF THE AREA BY DAYBREAK MONDAY.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
MONDAY...
PRECIPITATION WILL HAVE LARGELY COME TO AN END FOR DAYBREAK MONDAY
WITH THE LOW PRESSURE RAPIDLY PULLING AWAY INTO THE CANADIAN
MARITIMES AND DRIER AIR/HIGH PRESSURE MOVING IN FROM THE WEST.
INCREASING SUNSHINE EXPECTED DURING THE DAY...WITH TEMPS TOPPING
OUT IN THE UPPER 20S TO MID 30S. HOWEVER AS WE GET TOWARDS
MIDDAY/AFTERNOON TIGHTENING GRADIENT WILL ALLOW NORTHWEST FLOW TO
BECOME BLUSTERY...WITH GUSTS OF 25 TO 30 MPH...25 TO 35 MPH ON THE
CAPE AND ISLANDS.

MONDAY NIGHT...
HIGH PRESSURE SETTLES OVER THE AREA WITH CLEAR SKIES EXPECTED.
GIVEN OUR SNOWPACK IN PLACE AND LIGHT WINDS...SHOULD BE ANOTHER
NIGHT FOR EXCELLENT RADIATIONAL COOLING. BECAUSE OF THIS DID
GENERALLY GO BELOW MODEL GUIDANCE FOR MIN TEMPS...LOOKING TO
ANTICIPATED SURFACE DEWPOINTS FOR A GUIDELINE ON HOW LOW WE CAN
GO. MAY SEE SOME SPOTS IN THE INTERIOR DROP BELOW ZERO.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
BIG PICTURE... THE BROAD UPPER FLOW CONTINUES TO FEATURE A TROUGH
TRANSITING EAST ACROSS THE COUNTRY...REACHING THE EASTERN USA DURING
THE LATE WEEK AND LINGERING THROUGH THE WEEKEND. MEANWHILE AN UPPER
RIDGE SHIFTS FROM THE PACIFIC OCEAN BACK ASHORE ONTO THE WEST COAST.
CONTOUR HEIGHTS IN THE TROUGH ARE LOWEST THURSDAY-FRIDAY AND NEAR
NORMAL OVER THE WEEKEND. THIS MEANS A TREND TO COLDER TEMPS THURSDAY-
FRIDAY FOLLOWED BY A TREND CLOSER TO NORMAL OVER THE WEEKEND.

DAILIES...

TUESDAY... HIGH PRESSURE OVER THE REGION MOVES OFFSHORE BY AFTERNOON
WITH AIRFLOW SWINGING FROM NORTHWEST TO SOUTHWEST. THE SURFACE
AIRMASS STARTS OUT QUITE DRY WITH DEW POINTS IN THE SINGLE NUMBERS
BELOW ZERO TO START...CLIMBING TO 5-10 ABOVE BY EVENING. MODEL CROSS
SECTIONS SHOW INCREASING MOISTURE MORNING AND AFTERNOON ABOVE 700
MB. THIS SUGGESTS INCREASING MID AND HIGH CLOUDS WHILE DRY BENEATH.
LOW LEVEL JETS FROM THE CAROLINAS AND MIDWEST AND THE SURFACE
PRESSURE GRADIENT ALL SUGGEST THE INFLOW AND ISENTROPIC LIFT WILL
REMAIN TO OUR WEST THROUGH THE DAY...POSSIBLY ENTERING WESTERN MA/CT
AT OR AFTER 21Z. SO WE EXPECT INCREASING CLOUDS TUESDAY BUT
OTHERWISE DRY WEATHER THROUGH THE DAY. POSSIBLE LIGHT SNOW AROUND
THE EVENING RUSH HOUR IN THE CT RIVER VALLEY. TEMPS SHOULD REACH THE
MID 20S TO AROUND 30.

TUESDAY NIGHT-WEDNESDAY... NORTHERN AND SOUTHERN STREAM SHORTWAVES
MERGE OVER THE GREAT LAKES AND TRACK INTO CANADA. THIS BRINGS A MILD
FLOW OF AIR UP OVER NEW ENGLAND. THE LEADING EDGE OF THIS AIR
REACHES WESTERN SECTIONS TUESDAY EVENING AND EASTERN SECTIONS
TUESDAY NIGHT. TEMPERATURE PROFILES SUPPORT AN INITIAL PERIOD OF
SNOW CHANGING TO RAIN OR FREEZING RAIN OVERNIGHT. ACTUALLY...THE
MODELS MAY NOT BE HANDLING WELL THE CHILLING MASS OF SNOW AND COLD
GROUND /A.K.A. THE GIANT ICECUBE/ WHICH WOULD MEAN THE ACTUAL MAX
SFC TEMPS WILL BE COOLER THAN MODEL FORECASTS. TEMPERATURES AT 925
AND 950 MB WILL BE IN THE 30S...SO EXPECT SURFACE TEMPS NO HIGHER
THAN THE LOWER 40S.

THE SURFACE LOW PRESSURE AREA PASSES WELL NORTH OF NEW ENGLAND
WEDNESDAY AND SWINGS A COLD FRONT THROUGH THE REGION DURING THE
AFTERNOON OR EVENING. MOISTURE CROSS SECTIONS SHOW DECREASING RH IN
THE LIFT AND NUCLEATION ZONES ALOFT WEDNESDAY MORNING...SO THE TREND
THROUGH THE DAY SHOULD BE TO DIMINISHING POPS.

THURSDAY-FRIDAY... THE WEDNESDAY COLD FRONT WILL ALIGN WITH THE
UPPER FLOW AS IT MOVES SOUTH OF NEW ENGLAND...SLOWING ITS OFFSHORE
PROGRESS TO A CRAWL. MEANWHILE WE WILL BE UNDER THE RIGHT ENTRANCE
REGION OF THE SUPPORTING UPPER JET...A SOURCE OF UPPER VENTING. THIS
SHOULD SUPPORT LINGERING CLOUDS AND A CHANCE OF PCPN...WITH TEMPS
SUPPORTIVE OF SNOW. BEST CHANCE SOUTH COAST...LESSER CHANCE FARTHER
NORTH. THE JET AND SURFACE FRONT SWEEP OFFSHORE THURSDAY NIGHT. HIGH
PRESSURE THEN MOVES OVER THE EASTERN USA FOR FRIDAY. TEMPS ALOFT
SUPPORT MAX SFC TEMPS IN THE 20S.

SATURDAY-SUNDAY... ANOTHER NORTHERN STREAM SHORTWAVE AND COLD FRONT
SWINGS THROUGH THE FLOW SATURDAY. CROSS SECTIONS SHOW SOME MOISTURE
ALOFT BUT MOST OF IT IS CONCENTRATED TO OUR NORTH.  ALSO JUST
LIMITED LIFT TO WORK ON THAT MOISTURE. WE WILL HAVE 25-50 PCT SKY
COVER AND NIL POPS. HIGH PRESSURE THEN BUILDS FOR SUNDAY.

&&

.AVIATION /02Z MONDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...

TONIGHT...MODERATE CONFIDENCE. MVFR CIGS WITH PATCHES OF IFR
VALUES. VSBYS MOSTLY 1 TO 3 MILES WITH A ZONE FROM SOUTHERN CT
THROUGH RI AND SE MASS WHERE VSBYS ARE LIFR AT 1/2 MILE TO 1 MILE.
EXPECT THESE CONDITIONS TO LINGER THROUGH MIDNIGHT. THE ZONE OF
LOWER VSBYS AND SNOWFALL RATES COULD WOBBLE NORTH A FEW MILES AND
BRIEFLY APPROACH BOSTON BUT SHOULD PRIMARILY REMAIN TO THE SOUTH.

SOUTH FLOW BRINGS ENOUGH MILDER AIR NORTH TO MIX OR CHANGE THE
PCPN TO RAIN ON NANTUCKET AND PARTS OF THE OUTER CAPE. BULK OF THE
SNOW SHOULD ENDS 06Z WEST TO 10Z EAST /LATE TONIGHT AND EARLY
MONDAY/ MUCH OF THE REGION SHOULD IMPROVE TO VFR CONDITIONS BY
12-13Z MONDAY.

KBOS TAF...CONFIDENT IN OVERALL TRENDS BUT THERE IS UNCERTAINTY ON
TIMING. VSBYS BELOW 1 MILE SHOULD REMAIN TO THE SOUTH BUT COULD
BRIEFLY VISIT THE AIRPORT EARLY TONIGHT. THE BULK OF ACCUMULATING
SNOW IS EXPECTED BY MIDNIGHT.

KBDL TAF...CONFIDENT IN OVERALL TRENDS BUT THERE IS UNCERTAINTY ON
TIMING. BULK OF ACCUMULATING SNOW WITH IFR TO LIFR CONDITIONS
EXPECTED BY MIDNIGHT.

MONDAY AND MONDAY NIGHT...HIGH CONFIDENCE VFR. NORTHWEST WINDS
GUSTING TO 25 TO 30 MPH ACROSS MUCH OF THE AREA DURING MONDAY
AFTERNOON...25 TO 35 MPH GUSTS CAPE/ISLANDS. WINDS DIMINISHING
TOWARDS SUNSET.

OUTLOOK...TUESDAY THROUGH FRIDAY...

TUESDAY...MODERATE CONFIDENCE. VFR DURING THE DAY WITH INCREASING
SKY COVER. MVFR CIGS/VSBYS POSSIBLE LATE IN THE DAY CT RIVER VALLEY.

TUESDAY NIGHT-WEDNESDAY...MODERATE CONFIDENCE. CONDITIONS LOWERING
TO IFR/LIFR. INITIALLY SNOW BUT CHANGING TO SLEET/FREEZING RAIN
DURING THE NIGHT AND RAIN IN THE COASTAL PLAIN OVERNIGHT. PCPN
CHANGES TO RAIN ALL AREAS WEDNESDAY...BUT COLD SURFACES COULD
MAINTAIN A FREEZING RAIN ELEMENT WEDNESDAY MORNING. COLDER AIR MOVES
IN WEDNESDAY NIGHT CHANGING ANY RAIN TO SNOW.

THURSDAY...LOW CONFIDENCE. VFR NORTH OF A HFD-BOS LINE. MVFR CIGS
AND AREAS OF MVFR/IFR VSBYS IN SNOW...DIMINISHING BY EVENING.
NORTHWEST WINDS GUSTING TO 20 KNOTS.

FRIDAY...MODERATE CONFIDENCE. VFR.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...HIGH CONFIDENCE.

A WEAK WAVE OF LOW PRESSURE MOVES ACROSS THE WATERS TONIGHT.
THIS SYSTEM REALLY INTENSIFIES AS IT MOVES INTO THE CANADIAN
MARITIMES NEAR DAYBREAK MONDAY...SO WESTERLY WIND GUSTS MAY REACH
20 TO 25 KNOTS NEAR 12Z MONDAY. OTHERWISE...RAIN AND SNOW THIS
EVENING AND TONIGHT WILL REDUCE VISIBILITIES AT TIMES FOR
MARINERS.

MONDAY...AS THE LOW PRESSURE GOING INTO THE CANADIAN MARITIMES
INTENSIFIES...INCREASING NORTHWEST WINDS ARE EXPECTED OVER THE
SOUTHERN NEW ENGLAND COASTAL WATERS...WITH GALE FORCE GUSTS
EXPECTED. GALE WARNINGS HAVE BEEN HOISTED FOR ALL COASTAL WATERS
FROM MIDDAY MONDAY INTO MONDAY NIGHT.

OUTLOOK...TUESDAY THROUGH FRIDAY..MODERATE CONFIDENCE.

TUESDAY... LINGERING 5 FOOT SEAS SOUTH AND EAST OF NANTUCKET IN THE
MORNING BUT DIMINISHING. NORTHWEST WINDS DIMINISHING FROM 20 KNOTS.
ANY SMALL CRAFT ADVISORY SHOULD END IN THE MORNING.

TUESDAY NIGHT-WEDNESDAY...SOUTH TO SOUTHWEST WINDS WILL INCREASE TO
20-25 KNOTS. SEAS WILL BUILD 6 TO 10 FEET ON THE OUTER WATERS AND ON
RI SOUND. REDUCED VSBYS...INITIALLY SNOW BUT CHANGING TO RAIN. A
SMALL CRAFT ADVISORY MAY BE NEEDED.

THURSDAY...NORTHWEST WIND GUSTING TO 25 KNOTS. SEAS 5 TO 8 FEET
MAINLY ON THE OUTER WATERS...DIMINISHING LATE. A SMALL CRAFT
ADVISORY MAY BE NEEDED.

FRIDAY... SHIFTING WINDS LESS THAN 20 KNOTS. SEAS LESS THAN 5 FEET.
QUIET WEATHER.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR CTZ002>004.
MA...WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR MAZ017>021.
     WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR MAZ002>016-
     022>024-026.
RI...WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR RIZ002>008.
     WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR RIZ001.
MARINE...GALE WARNING FROM 11 AM MONDAY TO 4 AM EST TUESDAY FOR ANZ231-
     232-250-251-254-255.
     GALE WARNING FROM 11 AM TO 11 PM EST MONDAY FOR ANZ233>235-237-
     256.
     GALE WARNING FROM 11 AM TO 8 PM EST MONDAY FOR ANZ230-236.

&&

$$
SYNOPSIS...WTB/NMB
NEAR TERM...FRANK/NMB
SHORT TERM...NMB
LONG TERM...WTB
AVIATION...WTB/NMB
MARINE...WTB/NMB




000
FXUS61 KBOX 020202
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
902 PM EST SUN MAR 1 2015

.SYNOPSIS...

A FAST MOVING LOW PRESSURE SYSTEM WILL BRING ACCUMULATING SNOW
THIS EVENING AND TONIGHT WITH THE HIGHEST AMOUNTS EXPECTED SOUTH
OF THE MASSACHUSETTS TURNPIKE. HIGH PRESSURE BRINGS DRY COLD AIR
FOR THE EARLY WEEK. LOW PRESSURE FROM NORTHERN CANADA AND
ASSOCIATED LOW FORMING OVER THE PLAINS MONDAY WILL MERGE...THEN
PASS WEST AND NORTH OF NEW ENGLAND. THIS WILL SWING A COLD FRONT
ACROSS THE REGION ON WEDNESDAY. DRY AND COLD WEATHER RETURNS FOR
THE END OF THE WEEK. ANOTHER COLD FRONT MOVES THROUGH ON SATURDAY.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...

9 PM UPDATE...

WIDESPREAD LIGHT TO MODERATE SNOW WAS AFFECTING ALL OF SOUTHERN NEW
ENGLAND THIS EVENING AS RESULT OF BROAD SCALE MID LEVEL LIFT.  THERE
WAS BAND OF MODERATE TO HEAVY SNOW ACROSS SOUTHERN RI AND SOUTHEAST
MA.  THIS A RESULT OF BETTER FORCING/MOISTURE WITH A STRONGER LOW
LEVEL JET IMPINGING ON THAT REGION.  SURFACE WINDS WERE VERY LIGHT
FROM THE SOUTH OR EVEN CALM ALONG THE SOUTH COAST...WHICH IS LIKELY
AIDING IN SOME LOW LEVEL CONVERGENCE.

NOT TOO MANY CHANGES NEEDED TO THE FORECAST THIS EVENING.  BASED ON
THE LATEST DATA...PROBABLY REMAINS PRETTY MUCH ALL SNOW EVEN FOR
MOST OF CAPE COD.  PERHAPS A BRIEF CHANGE OVER AT THE END NEAR
CHATHAM AT THE END...BUT A WIDESPREAD 3 TO 6 INCHES OF SNOW
EXPECTED.  IT MIGHT END UP CLOSE TO A MARGINAL WARNING ACROSS THE
UPPER CAPE...BUT NOT ENOUGH CONFIDENCE TO PULL THE TRIGGER.
NANTUCKET HAS JUST CHANGED TO RAIN AND PROBABLY WILL SEE MARTHAS
VINEYARD GO OVER IN THE NEXT FEW HOURS.

OTHERWISE...LOOKS LIKE 2 TO 4 INCHES NORTH OF THE PIKE...3 TO 6
INCHES SOUTH OF THE PIKE.  STILL EXPECT A SWATH OF 4 TO 8 INCHES
ACROSS PORTIONS OF RHODE ISLAND AND SOUTHEAST MA WITH THE HELP OF
THE LOW LEVEL JET AND WILL BE CONTINUING THE WINTER STORM WARNING
FOR THAT REGION.

LATEST MODELS DATA IN FAIRLY GOOD AGREEMENT THAT ALL BULK OF THE
ACCUMULATIONS SNOW WINDS DOWN FROM WEST TO EAST BETWEEN 11 PM AND 1
OR 2 AM...BUT MAY LINGER A BIT LONGER ACROSS THE CAPE/ISLANDS.

PREVIOUS DISCUSSION:

LOW PRESSURE EMERGING FROM THE MID ATLANTIC COASTLINE IS EXPECTED
TO PASS SOUTHEAST OF NANTUCKET TONIGHT...BRINGING A WIDESPREAD
SNOW TO SOUTHERN NEW ENGLAND. SURFACE OBS AS OF 21Z INDICATE THAT
SNOW HAS OVERSPREAD THE ENTIRE AREA. THE STRONGEST RADAR
RETURNS AT 21Z WERE NEAR THE SOUTH COAST OF CT INTO RI...AND TO
THE SOUTHWEST. THE BETTER FORCING FROM THIS EVENT IS EXPECTED TO OCCUR
TO THE SOUTH OF THE MA TURNPIKE. 12Z MODELS WERE IN DECENT
AGREEMENT ON PLACING THE HIGHEST QPF IN THAT AREA.

BECAUSE OF THE QUICK HITTING NATURE OF THIS SYSTEM WITH A SHORT
LIVED WINDOW FOR VERY STRONG LIFT/FORCING...CONTINUE TO THINK THAT
FOR MOST OF THE REGION WINTER WEATHER ADVISORY/S FOR 3 TO 6 INCHES
OF SNOW WILL COVER THIS EVENT. HOWEVER...GIVEN THERE IS NICE
OMEGA IN THE SNOW GROWTH REGION...WE MIGHT BE LOOKING AT SOME
DECENT RATIOS. SO WE STILL CAN NOT RULE OUT THE LOW RISK OF
REACHING WARNING AMOUNTS...ESPECIALLY ACROSS NORTHERN CT AND
NORTHWEST RI.

WE DID UPGRADED BLOCK ISLAND TO A WINTER STORM WARNING FOR THE
LATE AFTERNOON FORECAST PACKAGE. THERE MAY BE SOME MIXING WITH
RAIN IN THIS AREA AT TIMES.

EXPECT THIS TO BE A SNOW EVENT FOR THE VAST MAJORITY OF SOUTHERN
NEW ENGLAND. IT DOES BECOME A VERY CLOSE CALL NEAR THE SOUTH
COAST...BUT WERE LEANING TOWARDS IT STAYING MAINLY WET SNOW.
CONTINUED THE HIGH END WINTER WEATHER ADVISORY FOR THE CAPE
BECAUSE THEY MAY CHANGE TO RAIN FOR A TIME...ESPECIALLY EAST OF
HYANNIS. IF THE CHANGE OVER DOES NOT OCCUR...SNOWFALL TOTALS MAY
BE SOMEWHAT HIGHER. THE PRECIPITATION IS EXPECTED TO COME TO AN
END ACROSS THE MAJORITY OF THE AREA BY DAYBREAK MONDAY.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
MONDAY...
PRECIPITATION WILL HAVE LARGELY COME TO AN END FOR DAYBREAK MONDAY
WITH THE LOW PRESSURE RAPIDLY PULLING AWAY INTO THE CANADIAN
MARITIMES AND DRIER AIR/HIGH PRESSURE MOVING IN FROM THE WEST.
INCREASING SUNSHINE EXPECTED DURING THE DAY...WITH TEMPS TOPPING
OUT IN THE UPPER 20S TO MID 30S. HOWEVER AS WE GET TOWARDS
MIDDAY/AFTERNOON TIGHTENING GRADIENT WILL ALLOW NORTHWEST FLOW TO
BECOME BLUSTERY...WITH GUSTS OF 25 TO 30 MPH...25 TO 35 MPH ON THE
CAPE AND ISLANDS.

MONDAY NIGHT...
HIGH PRESSURE SETTLES OVER THE AREA WITH CLEAR SKIES EXPECTED.
GIVEN OUR SNOWPACK IN PLACE AND LIGHT WINDS...SHOULD BE ANOTHER
NIGHT FOR EXCELLENT RADIATIONAL COOLING. BECAUSE OF THIS DID
GENERALLY GO BELOW MODEL GUIDANCE FOR MIN TEMPS...LOOKING TO
ANTICIPATED SURFACE DEWPOINTS FOR A GUIDELINE ON HOW LOW WE CAN
GO. MAY SEE SOME SPOTS IN THE INTERIOR DROP BELOW ZERO.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
BIG PICTURE... THE BROAD UPPER FLOW CONTINUES TO FEATURE A TROUGH
TRANSITING EAST ACROSS THE COUNTRY...REACHING THE EASTERN USA DURING
THE LATE WEEK AND LINGERING THROUGH THE WEEKEND. MEANWHILE AN UPPER
RIDGE SHIFTS FROM THE PACIFIC OCEAN BACK ASHORE ONTO THE WEST COAST.
CONTOUR HEIGHTS IN THE TROUGH ARE LOWEST THURSDAY-FRIDAY AND NEAR
NORMAL OVER THE WEEKEND. THIS MEANS A TREND TO COLDER TEMPS THURSDAY-
FRIDAY FOLLOWED BY A TREND CLOSER TO NORMAL OVER THE WEEKEND.

DAILIES...

TUESDAY... HIGH PRESSURE OVER THE REGION MOVES OFFSHORE BY AFTERNOON
WITH AIRFLOW SWINGING FROM NORTHWEST TO SOUTHWEST. THE SURFACE
AIRMASS STARTS OUT QUITE DRY WITH DEW POINTS IN THE SINGLE NUMBERS
BELOW ZERO TO START...CLIMBING TO 5-10 ABOVE BY EVENING. MODEL CROSS
SECTIONS SHOW INCREASING MOISTURE MORNING AND AFTERNOON ABOVE 700
MB. THIS SUGGESTS INCREASING MID AND HIGH CLOUDS WHILE DRY BENEATH.
LOW LEVEL JETS FROM THE CAROLINAS AND MIDWEST AND THE SURFACE
PRESSURE GRADIENT ALL SUGGEST THE INFLOW AND ISENTROPIC LIFT WILL
REMAIN TO OUR WEST THROUGH THE DAY...POSSIBLY ENTERING WESTERN MA/CT
AT OR AFTER 21Z. SO WE EXPECT INCREASING CLOUDS TUESDAY BUT
OTHERWISE DRY WEATHER THROUGH THE DAY. POSSIBLE LIGHT SNOW AROUND
THE EVENING RUSH HOUR IN THE CT RIVER VALLEY. TEMPS SHOULD REACH THE
MID 20S TO AROUND 30.

TUESDAY NIGHT-WEDNESDAY... NORTHERN AND SOUTHERN STREAM SHORTWAVES
MERGE OVER THE GREAT LAKES AND TRACK INTO CANADA. THIS BRINGS A MILD
FLOW OF AIR UP OVER NEW ENGLAND. THE LEADING EDGE OF THIS AIR
REACHES WESTERN SECTIONS TUESDAY EVENING AND EASTERN SECTIONS
TUESDAY NIGHT. TEMPERATURE PROFILES SUPPORT AN INITIAL PERIOD OF
SNOW CHANGING TO RAIN OR FREEZING RAIN OVERNIGHT. ACTUALLY...THE
MODELS MAY NOT BE HANDLING WELL THE CHILLING MASS OF SNOW AND COLD
GROUND /A.K.A. THE GIANT ICECUBE/ WHICH WOULD MEAN THE ACTUAL MAX
SFC TEMPS WILL BE COOLER THAN MODEL FORECASTS. TEMPERATURES AT 925
AND 950 MB WILL BE IN THE 30S...SO EXPECT SURFACE TEMPS NO HIGHER
THAN THE LOWER 40S.

THE SURFACE LOW PRESSURE AREA PASSES WELL NORTH OF NEW ENGLAND
WEDNESDAY AND SWINGS A COLD FRONT THROUGH THE REGION DURING THE
AFTERNOON OR EVENING. MOISTURE CROSS SECTIONS SHOW DECREASING RH IN
THE LIFT AND NUCLEATION ZONES ALOFT WEDNESDAY MORNING...SO THE TREND
THROUGH THE DAY SHOULD BE TO DIMINISHING POPS.

THURSDAY-FRIDAY... THE WEDNESDAY COLD FRONT WILL ALIGN WITH THE
UPPER FLOW AS IT MOVES SOUTH OF NEW ENGLAND...SLOWING ITS OFFSHORE
PROGRESS TO A CRAWL. MEANWHILE WE WILL BE UNDER THE RIGHT ENTRANCE
REGION OF THE SUPPORTING UPPER JET...A SOURCE OF UPPER VENTING. THIS
SHOULD SUPPORT LINGERING CLOUDS AND A CHANCE OF PCPN...WITH TEMPS
SUPPORTIVE OF SNOW. BEST CHANCE SOUTH COAST...LESSER CHANCE FARTHER
NORTH. THE JET AND SURFACE FRONT SWEEP OFFSHORE THURSDAY NIGHT. HIGH
PRESSURE THEN MOVES OVER THE EASTERN USA FOR FRIDAY. TEMPS ALOFT
SUPPORT MAX SFC TEMPS IN THE 20S.

SATURDAY-SUNDAY... ANOTHER NORTHERN STREAM SHORTWAVE AND COLD FRONT
SWINGS THROUGH THE FLOW SATURDAY. CROSS SECTIONS SHOW SOME MOISTURE
ALOFT BUT MOST OF IT IS CONCENTRATED TO OUR NORTH.  ALSO JUST
LIMITED LIFT TO WORK ON THAT MOISTURE. WE WILL HAVE 25-50 PCT SKY
COVER AND NIL POPS. HIGH PRESSURE THEN BUILDS FOR SUNDAY.

&&

.AVIATION /02Z MONDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...

TONIGHT...MODERATE CONFIDENCE. MVFR CIGS WITH PATCHES OF IFR
VALUES. VSBYS MOSTLY 1 TO 3 MILES WITH A ZONE FROM SOUTHERN CT
THROUGH RI AND SE MASS WHERE VSBYS ARE LIFR AT 1/2 MILE TO 1 MILE.
EXPECT THESE CONDITIONS TO LINGER THROUGH MIDNIGHT. THE ZONE OF
LOWER VSBYS AND SNOWFALL RATES COULD WOBBLE NORTH A FEW MILES AND
BRIEFLY APPROACH BOSTON BUT SHOULD PRIMARILY REMAIN TO THE SOUTH.

SOUTH FLOW BRINGS ENOUGH MILDER AIR NORTH TO MIX OR CHANGE THE
PCPN TO RAIN ON NANTUCKET AND PARTS OF THE OUTER CAPE. BULK OF THE
SNOW SHOULD ENDS 06Z WEST TO 10Z EAST /LATE TONIGHT AND EARLY
MONDAY/ MUCH OF THE REGION SHOULD IMPROVE TO VFR CONDITIONS BY
12-13Z MONDAY.

KBOS TAF...CONFIDENT IN OVERALL TRENDS BUT THERE IS UNCERTAINTY ON
TIMING. VSBYS BELOW 1 MILE SHOULD REMAIN TO THE SOUTH BUT COULD
BRIEFLY VISIT THE AIRPORT EARLY TONIGHT. THE BULK OF ACCUMULATING
SNOW IS EXPECTED BY MIDNIGHT.

KBDL TAF...CONFIDENT IN OVERALL TRENDS BUT THERE IS UNCERTAINTY ON
TIMING. BULK OF ACCUMULATING SNOW WITH IFR TO LIFR CONDITIONS
EXPECTED BY MIDNIGHT.

MONDAY AND MONDAY NIGHT...HIGH CONFIDENCE VFR. NORTHWEST WINDS
GUSTING TO 25 TO 30 MPH ACROSS MUCH OF THE AREA DURING MONDAY
AFTERNOON...25 TO 35 MPH GUSTS CAPE/ISLANDS. WINDS DIMINISHING
TOWARDS SUNSET.

OUTLOOK...TUESDAY THROUGH FRIDAY...

TUESDAY...MODERATE CONFIDENCE. VFR DURING THE DAY WITH INCREASING
SKY COVER. MVFR CIGS/VSBYS POSSIBLE LATE IN THE DAY CT RIVER VALLEY.

TUESDAY NIGHT-WEDNESDAY...MODERATE CONFIDENCE. CONDITIONS LOWERING
TO IFR/LIFR. INITIALLY SNOW BUT CHANGING TO SLEET/FREEZING RAIN
DURING THE NIGHT AND RAIN IN THE COASTAL PLAIN OVERNIGHT. PCPN
CHANGES TO RAIN ALL AREAS WEDNESDAY...BUT COLD SURFACES COULD
MAINTAIN A FREEZING RAIN ELEMENT WEDNESDAY MORNING. COLDER AIR MOVES
IN WEDNESDAY NIGHT CHANGING ANY RAIN TO SNOW.

THURSDAY...LOW CONFIDENCE. VFR NORTH OF A HFD-BOS LINE. MVFR CIGS
AND AREAS OF MVFR/IFR VSBYS IN SNOW...DIMINISHING BY EVENING.
NORTHWEST WINDS GUSTING TO 20 KNOTS.

FRIDAY...MODERATE CONFIDENCE. VFR.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...HIGH CONFIDENCE.

A WEAK WAVE OF LOW PRESSURE MOVES ACROSS THE WATERS TONIGHT.
THIS SYSTEM REALLY INTENSIFIES AS IT MOVES INTO THE CANADIAN
MARITIMES NEAR DAYBREAK MONDAY...SO WESTERLY WIND GUSTS MAY REACH
20 TO 25 KNOTS NEAR 12Z MONDAY. OTHERWISE...RAIN AND SNOW THIS
EVENING AND TONIGHT WILL REDUCE VISIBILITIES AT TIMES FOR
MARINERS.

MONDAY...AS THE LOW PRESSURE GOING INTO THE CANADIAN MARITIMES
INTENSIFIES...INCREASING NORTHWEST WINDS ARE EXPECTED OVER THE
SOUTHERN NEW ENGLAND COASTAL WATERS...WITH GALE FORCE GUSTS
EXPECTED. GALE WARNINGS HAVE BEEN HOISTED FOR ALL COASTAL WATERS
FROM MIDDAY MONDAY INTO MONDAY NIGHT.

OUTLOOK...TUESDAY THROUGH FRIDAY..MODERATE CONFIDENCE.

TUESDAY... LINGERING 5 FOOT SEAS SOUTH AND EAST OF NANTUCKET IN THE
MORNING BUT DIMINISHING. NORTHWEST WINDS DIMINISHING FROM 20 KNOTS.
ANY SMALL CRAFT ADVISORY SHOULD END IN THE MORNING.

TUESDAY NIGHT-WEDNESDAY...SOUTH TO SOUTHWEST WINDS WILL INCREASE TO
20-25 KNOTS. SEAS WILL BUILD 6 TO 10 FEET ON THE OUTER WATERS AND ON
RI SOUND. REDUCED VSBYS...INITIALLY SNOW BUT CHANGING TO RAIN. A
SMALL CRAFT ADVISORY MAY BE NEEDED.

THURSDAY...NORTHWEST WIND GUSTING TO 25 KNOTS. SEAS 5 TO 8 FEET
MAINLY ON THE OUTER WATERS...DIMINISHING LATE. A SMALL CRAFT
ADVISORY MAY BE NEEDED.

FRIDAY... SHIFTING WINDS LESS THAN 20 KNOTS. SEAS LESS THAN 5 FEET.
QUIET WEATHER.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR CTZ002>004.
MA...WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR MAZ017>021.
     WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR MAZ002>016-
     022>024-026.
RI...WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR RIZ002>008.
     WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR RIZ001.
MARINE...GALE WARNING FROM 11 AM MONDAY TO 4 AM EST TUESDAY FOR ANZ231-
     232-250-251-254-255.
     GALE WARNING FROM 11 AM TO 11 PM EST MONDAY FOR ANZ233>235-237-
     256.
     GALE WARNING FROM 11 AM TO 8 PM EST MONDAY FOR ANZ230-236.

&&

$$
SYNOPSIS...WTB/NMB
NEAR TERM...FRANK/NMB
SHORT TERM...NMB
LONG TERM...WTB
AVIATION...WTB/NMB
MARINE...WTB/NMB




000
FXUS61 KBOX 020202
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
902 PM EST SUN MAR 1 2015

.SYNOPSIS...

A FAST MOVING LOW PRESSURE SYSTEM WILL BRING ACCUMULATING SNOW
THIS EVENING AND TONIGHT WITH THE HIGHEST AMOUNTS EXPECTED SOUTH
OF THE MASSACHUSETTS TURNPIKE. HIGH PRESSURE BRINGS DRY COLD AIR
FOR THE EARLY WEEK. LOW PRESSURE FROM NORTHERN CANADA AND
ASSOCIATED LOW FORMING OVER THE PLAINS MONDAY WILL MERGE...THEN
PASS WEST AND NORTH OF NEW ENGLAND. THIS WILL SWING A COLD FRONT
ACROSS THE REGION ON WEDNESDAY. DRY AND COLD WEATHER RETURNS FOR
THE END OF THE WEEK. ANOTHER COLD FRONT MOVES THROUGH ON SATURDAY.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...

9 PM UPDATE...

WIDESPREAD LIGHT TO MODERATE SNOW WAS AFFECTING ALL OF SOUTHERN NEW
ENGLAND THIS EVENING AS RESULT OF BROAD SCALE MID LEVEL LIFT.  THERE
WAS BAND OF MODERATE TO HEAVY SNOW ACROSS SOUTHERN RI AND SOUTHEAST
MA.  THIS A RESULT OF BETTER FORCING/MOISTURE WITH A STRONGER LOW
LEVEL JET IMPINGING ON THAT REGION.  SURFACE WINDS WERE VERY LIGHT
FROM THE SOUTH OR EVEN CALM ALONG THE SOUTH COAST...WHICH IS LIKELY
AIDING IN SOME LOW LEVEL CONVERGENCE.

NOT TOO MANY CHANGES NEEDED TO THE FORECAST THIS EVENING.  BASED ON
THE LATEST DATA...PROBABLY REMAINS PRETTY MUCH ALL SNOW EVEN FOR
MOST OF CAPE COD.  PERHAPS A BRIEF CHANGE OVER AT THE END NEAR
CHATHAM AT THE END...BUT A WIDESPREAD 3 TO 6 INCHES OF SNOW
EXPECTED.  IT MIGHT END UP CLOSE TO A MARGINAL WARNING ACROSS THE
UPPER CAPE...BUT NOT ENOUGH CONFIDENCE TO PULL THE TRIGGER.
NANTUCKET HAS JUST CHANGED TO RAIN AND PROBABLY WILL SEE MARTHAS
VINEYARD GO OVER IN THE NEXT FEW HOURS.

OTHERWISE...LOOKS LIKE 2 TO 4 INCHES NORTH OF THE PIKE...3 TO 6
INCHES SOUTH OF THE PIKE.  STILL EXPECT A SWATH OF 4 TO 8 INCHES
ACROSS PORTIONS OF RHODE ISLAND AND SOUTHEAST MA WITH THE HELP OF
THE LOW LEVEL JET AND WILL BE CONTINUING THE WINTER STORM WARNING
FOR THAT REGION.

LATEST MODELS DATA IN FAIRLY GOOD AGREEMENT THAT ALL BULK OF THE
ACCUMULATIONS SNOW WINDS DOWN FROM WEST TO EAST BETWEEN 11 PM AND 1
OR 2 AM...BUT MAY LINGER A BIT LONGER ACROSS THE CAPE/ISLANDS.

PREVIOUS DISCUSSION:

LOW PRESSURE EMERGING FROM THE MID ATLANTIC COASTLINE IS EXPECTED
TO PASS SOUTHEAST OF NANTUCKET TONIGHT...BRINGING A WIDESPREAD
SNOW TO SOUTHERN NEW ENGLAND. SURFACE OBS AS OF 21Z INDICATE THAT
SNOW HAS OVERSPREAD THE ENTIRE AREA. THE STRONGEST RADAR
RETURNS AT 21Z WERE NEAR THE SOUTH COAST OF CT INTO RI...AND TO
THE SOUTHWEST. THE BETTER FORCING FROM THIS EVENT IS EXPECTED TO OCCUR
TO THE SOUTH OF THE MA TURNPIKE. 12Z MODELS WERE IN DECENT
AGREEMENT ON PLACING THE HIGHEST QPF IN THAT AREA.

BECAUSE OF THE QUICK HITTING NATURE OF THIS SYSTEM WITH A SHORT
LIVED WINDOW FOR VERY STRONG LIFT/FORCING...CONTINUE TO THINK THAT
FOR MOST OF THE REGION WINTER WEATHER ADVISORY/S FOR 3 TO 6 INCHES
OF SNOW WILL COVER THIS EVENT. HOWEVER...GIVEN THERE IS NICE
OMEGA IN THE SNOW GROWTH REGION...WE MIGHT BE LOOKING AT SOME
DECENT RATIOS. SO WE STILL CAN NOT RULE OUT THE LOW RISK OF
REACHING WARNING AMOUNTS...ESPECIALLY ACROSS NORTHERN CT AND
NORTHWEST RI.

WE DID UPGRADED BLOCK ISLAND TO A WINTER STORM WARNING FOR THE
LATE AFTERNOON FORECAST PACKAGE. THERE MAY BE SOME MIXING WITH
RAIN IN THIS AREA AT TIMES.

EXPECT THIS TO BE A SNOW EVENT FOR THE VAST MAJORITY OF SOUTHERN
NEW ENGLAND. IT DOES BECOME A VERY CLOSE CALL NEAR THE SOUTH
COAST...BUT WERE LEANING TOWARDS IT STAYING MAINLY WET SNOW.
CONTINUED THE HIGH END WINTER WEATHER ADVISORY FOR THE CAPE
BECAUSE THEY MAY CHANGE TO RAIN FOR A TIME...ESPECIALLY EAST OF
HYANNIS. IF THE CHANGE OVER DOES NOT OCCUR...SNOWFALL TOTALS MAY
BE SOMEWHAT HIGHER. THE PRECIPITATION IS EXPECTED TO COME TO AN
END ACROSS THE MAJORITY OF THE AREA BY DAYBREAK MONDAY.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
MONDAY...
PRECIPITATION WILL HAVE LARGELY COME TO AN END FOR DAYBREAK MONDAY
WITH THE LOW PRESSURE RAPIDLY PULLING AWAY INTO THE CANADIAN
MARITIMES AND DRIER AIR/HIGH PRESSURE MOVING IN FROM THE WEST.
INCREASING SUNSHINE EXPECTED DURING THE DAY...WITH TEMPS TOPPING
OUT IN THE UPPER 20S TO MID 30S. HOWEVER AS WE GET TOWARDS
MIDDAY/AFTERNOON TIGHTENING GRADIENT WILL ALLOW NORTHWEST FLOW TO
BECOME BLUSTERY...WITH GUSTS OF 25 TO 30 MPH...25 TO 35 MPH ON THE
CAPE AND ISLANDS.

MONDAY NIGHT...
HIGH PRESSURE SETTLES OVER THE AREA WITH CLEAR SKIES EXPECTED.
GIVEN OUR SNOWPACK IN PLACE AND LIGHT WINDS...SHOULD BE ANOTHER
NIGHT FOR EXCELLENT RADIATIONAL COOLING. BECAUSE OF THIS DID
GENERALLY GO BELOW MODEL GUIDANCE FOR MIN TEMPS...LOOKING TO
ANTICIPATED SURFACE DEWPOINTS FOR A GUIDELINE ON HOW LOW WE CAN
GO. MAY SEE SOME SPOTS IN THE INTERIOR DROP BELOW ZERO.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
BIG PICTURE... THE BROAD UPPER FLOW CONTINUES TO FEATURE A TROUGH
TRANSITING EAST ACROSS THE COUNTRY...REACHING THE EASTERN USA DURING
THE LATE WEEK AND LINGERING THROUGH THE WEEKEND. MEANWHILE AN UPPER
RIDGE SHIFTS FROM THE PACIFIC OCEAN BACK ASHORE ONTO THE WEST COAST.
CONTOUR HEIGHTS IN THE TROUGH ARE LOWEST THURSDAY-FRIDAY AND NEAR
NORMAL OVER THE WEEKEND. THIS MEANS A TREND TO COLDER TEMPS THURSDAY-
FRIDAY FOLLOWED BY A TREND CLOSER TO NORMAL OVER THE WEEKEND.

DAILIES...

TUESDAY... HIGH PRESSURE OVER THE REGION MOVES OFFSHORE BY AFTERNOON
WITH AIRFLOW SWINGING FROM NORTHWEST TO SOUTHWEST. THE SURFACE
AIRMASS STARTS OUT QUITE DRY WITH DEW POINTS IN THE SINGLE NUMBERS
BELOW ZERO TO START...CLIMBING TO 5-10 ABOVE BY EVENING. MODEL CROSS
SECTIONS SHOW INCREASING MOISTURE MORNING AND AFTERNOON ABOVE 700
MB. THIS SUGGESTS INCREASING MID AND HIGH CLOUDS WHILE DRY BENEATH.
LOW LEVEL JETS FROM THE CAROLINAS AND MIDWEST AND THE SURFACE
PRESSURE GRADIENT ALL SUGGEST THE INFLOW AND ISENTROPIC LIFT WILL
REMAIN TO OUR WEST THROUGH THE DAY...POSSIBLY ENTERING WESTERN MA/CT
AT OR AFTER 21Z. SO WE EXPECT INCREASING CLOUDS TUESDAY BUT
OTHERWISE DRY WEATHER THROUGH THE DAY. POSSIBLE LIGHT SNOW AROUND
THE EVENING RUSH HOUR IN THE CT RIVER VALLEY. TEMPS SHOULD REACH THE
MID 20S TO AROUND 30.

TUESDAY NIGHT-WEDNESDAY... NORTHERN AND SOUTHERN STREAM SHORTWAVES
MERGE OVER THE GREAT LAKES AND TRACK INTO CANADA. THIS BRINGS A MILD
FLOW OF AIR UP OVER NEW ENGLAND. THE LEADING EDGE OF THIS AIR
REACHES WESTERN SECTIONS TUESDAY EVENING AND EASTERN SECTIONS
TUESDAY NIGHT. TEMPERATURE PROFILES SUPPORT AN INITIAL PERIOD OF
SNOW CHANGING TO RAIN OR FREEZING RAIN OVERNIGHT. ACTUALLY...THE
MODELS MAY NOT BE HANDLING WELL THE CHILLING MASS OF SNOW AND COLD
GROUND /A.K.A. THE GIANT ICECUBE/ WHICH WOULD MEAN THE ACTUAL MAX
SFC TEMPS WILL BE COOLER THAN MODEL FORECASTS. TEMPERATURES AT 925
AND 950 MB WILL BE IN THE 30S...SO EXPECT SURFACE TEMPS NO HIGHER
THAN THE LOWER 40S.

THE SURFACE LOW PRESSURE AREA PASSES WELL NORTH OF NEW ENGLAND
WEDNESDAY AND SWINGS A COLD FRONT THROUGH THE REGION DURING THE
AFTERNOON OR EVENING. MOISTURE CROSS SECTIONS SHOW DECREASING RH IN
THE LIFT AND NUCLEATION ZONES ALOFT WEDNESDAY MORNING...SO THE TREND
THROUGH THE DAY SHOULD BE TO DIMINISHING POPS.

THURSDAY-FRIDAY... THE WEDNESDAY COLD FRONT WILL ALIGN WITH THE
UPPER FLOW AS IT MOVES SOUTH OF NEW ENGLAND...SLOWING ITS OFFSHORE
PROGRESS TO A CRAWL. MEANWHILE WE WILL BE UNDER THE RIGHT ENTRANCE
REGION OF THE SUPPORTING UPPER JET...A SOURCE OF UPPER VENTING. THIS
SHOULD SUPPORT LINGERING CLOUDS AND A CHANCE OF PCPN...WITH TEMPS
SUPPORTIVE OF SNOW. BEST CHANCE SOUTH COAST...LESSER CHANCE FARTHER
NORTH. THE JET AND SURFACE FRONT SWEEP OFFSHORE THURSDAY NIGHT. HIGH
PRESSURE THEN MOVES OVER THE EASTERN USA FOR FRIDAY. TEMPS ALOFT
SUPPORT MAX SFC TEMPS IN THE 20S.

SATURDAY-SUNDAY... ANOTHER NORTHERN STREAM SHORTWAVE AND COLD FRONT
SWINGS THROUGH THE FLOW SATURDAY. CROSS SECTIONS SHOW SOME MOISTURE
ALOFT BUT MOST OF IT IS CONCENTRATED TO OUR NORTH.  ALSO JUST
LIMITED LIFT TO WORK ON THAT MOISTURE. WE WILL HAVE 25-50 PCT SKY
COVER AND NIL POPS. HIGH PRESSURE THEN BUILDS FOR SUNDAY.

&&

.AVIATION /02Z MONDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...

TONIGHT...MODERATE CONFIDENCE. MVFR CIGS WITH PATCHES OF IFR
VALUES. VSBYS MOSTLY 1 TO 3 MILES WITH A ZONE FROM SOUTHERN CT
THROUGH RI AND SE MASS WHERE VSBYS ARE LIFR AT 1/2 MILE TO 1 MILE.
EXPECT THESE CONDITIONS TO LINGER THROUGH MIDNIGHT. THE ZONE OF
LOWER VSBYS AND SNOWFALL RATES COULD WOBBLE NORTH A FEW MILES AND
BRIEFLY APPROACH BOSTON BUT SHOULD PRIMARILY REMAIN TO THE SOUTH.

SOUTH FLOW BRINGS ENOUGH MILDER AIR NORTH TO MIX OR CHANGE THE
PCPN TO RAIN ON NANTUCKET AND PARTS OF THE OUTER CAPE. BULK OF THE
SNOW SHOULD ENDS 06Z WEST TO 10Z EAST /LATE TONIGHT AND EARLY
MONDAY/ MUCH OF THE REGION SHOULD IMPROVE TO VFR CONDITIONS BY
12-13Z MONDAY.

KBOS TAF...CONFIDENT IN OVERALL TRENDS BUT THERE IS UNCERTAINTY ON
TIMING. VSBYS BELOW 1 MILE SHOULD REMAIN TO THE SOUTH BUT COULD
BRIEFLY VISIT THE AIRPORT EARLY TONIGHT. THE BULK OF ACCUMULATING
SNOW IS EXPECTED BY MIDNIGHT.

KBDL TAF...CONFIDENT IN OVERALL TRENDS BUT THERE IS UNCERTAINTY ON
TIMING. BULK OF ACCUMULATING SNOW WITH IFR TO LIFR CONDITIONS
EXPECTED BY MIDNIGHT.

MONDAY AND MONDAY NIGHT...HIGH CONFIDENCE VFR. NORTHWEST WINDS
GUSTING TO 25 TO 30 MPH ACROSS MUCH OF THE AREA DURING MONDAY
AFTERNOON...25 TO 35 MPH GUSTS CAPE/ISLANDS. WINDS DIMINISHING
TOWARDS SUNSET.

OUTLOOK...TUESDAY THROUGH FRIDAY...

TUESDAY...MODERATE CONFIDENCE. VFR DURING THE DAY WITH INCREASING
SKY COVER. MVFR CIGS/VSBYS POSSIBLE LATE IN THE DAY CT RIVER VALLEY.

TUESDAY NIGHT-WEDNESDAY...MODERATE CONFIDENCE. CONDITIONS LOWERING
TO IFR/LIFR. INITIALLY SNOW BUT CHANGING TO SLEET/FREEZING RAIN
DURING THE NIGHT AND RAIN IN THE COASTAL PLAIN OVERNIGHT. PCPN
CHANGES TO RAIN ALL AREAS WEDNESDAY...BUT COLD SURFACES COULD
MAINTAIN A FREEZING RAIN ELEMENT WEDNESDAY MORNING. COLDER AIR MOVES
IN WEDNESDAY NIGHT CHANGING ANY RAIN TO SNOW.

THURSDAY...LOW CONFIDENCE. VFR NORTH OF A HFD-BOS LINE. MVFR CIGS
AND AREAS OF MVFR/IFR VSBYS IN SNOW...DIMINISHING BY EVENING.
NORTHWEST WINDS GUSTING TO 20 KNOTS.

FRIDAY...MODERATE CONFIDENCE. VFR.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...HIGH CONFIDENCE.

A WEAK WAVE OF LOW PRESSURE MOVES ACROSS THE WATERS TONIGHT.
THIS SYSTEM REALLY INTENSIFIES AS IT MOVES INTO THE CANADIAN
MARITIMES NEAR DAYBREAK MONDAY...SO WESTERLY WIND GUSTS MAY REACH
20 TO 25 KNOTS NEAR 12Z MONDAY. OTHERWISE...RAIN AND SNOW THIS
EVENING AND TONIGHT WILL REDUCE VISIBILITIES AT TIMES FOR
MARINERS.

MONDAY...AS THE LOW PRESSURE GOING INTO THE CANADIAN MARITIMES
INTENSIFIES...INCREASING NORTHWEST WINDS ARE EXPECTED OVER THE
SOUTHERN NEW ENGLAND COASTAL WATERS...WITH GALE FORCE GUSTS
EXPECTED. GALE WARNINGS HAVE BEEN HOISTED FOR ALL COASTAL WATERS
FROM MIDDAY MONDAY INTO MONDAY NIGHT.

OUTLOOK...TUESDAY THROUGH FRIDAY..MODERATE CONFIDENCE.

TUESDAY... LINGERING 5 FOOT SEAS SOUTH AND EAST OF NANTUCKET IN THE
MORNING BUT DIMINISHING. NORTHWEST WINDS DIMINISHING FROM 20 KNOTS.
ANY SMALL CRAFT ADVISORY SHOULD END IN THE MORNING.

TUESDAY NIGHT-WEDNESDAY...SOUTH TO SOUTHWEST WINDS WILL INCREASE TO
20-25 KNOTS. SEAS WILL BUILD 6 TO 10 FEET ON THE OUTER WATERS AND ON
RI SOUND. REDUCED VSBYS...INITIALLY SNOW BUT CHANGING TO RAIN. A
SMALL CRAFT ADVISORY MAY BE NEEDED.

THURSDAY...NORTHWEST WIND GUSTING TO 25 KNOTS. SEAS 5 TO 8 FEET
MAINLY ON THE OUTER WATERS...DIMINISHING LATE. A SMALL CRAFT
ADVISORY MAY BE NEEDED.

FRIDAY... SHIFTING WINDS LESS THAN 20 KNOTS. SEAS LESS THAN 5 FEET.
QUIET WEATHER.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR CTZ002>004.
MA...WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR MAZ017>021.
     WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR MAZ002>016-
     022>024-026.
RI...WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR RIZ002>008.
     WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR RIZ001.
MARINE...GALE WARNING FROM 11 AM MONDAY TO 4 AM EST TUESDAY FOR ANZ231-
     232-250-251-254-255.
     GALE WARNING FROM 11 AM TO 11 PM EST MONDAY FOR ANZ233>235-237-
     256.
     GALE WARNING FROM 11 AM TO 8 PM EST MONDAY FOR ANZ230-236.

&&

$$
SYNOPSIS...WTB/NMB
NEAR TERM...FRANK/NMB
SHORT TERM...NMB
LONG TERM...WTB
AVIATION...WTB/NMB
MARINE...WTB/NMB




000
FXUS61 KBOX 012346
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
646 PM EST SUN MAR 1 2015

.SYNOPSIS...
A FAST MOVING LOW PRESSURE SYSTEM WILL BRING ACCUMULATING SNOW
THIS EVENING AND TONIGHT WITH THE HIGHEST AMOUNTS EXPECTED SOUTH
OF THE MASSACHUSETTS TURNPIKE. HIGH PRESSURE BRINGS DRY COLD AIR
FOR THE EARLY WEEK. LOW PRESSURE FROM NORTHERN CANADA AND
ASSOCIATED LOW FORMING OVER THE PLAINS MONDAY WILL MERGE...THEN
PASS WEST AND NORTH OF NEW ENGLAND. THIS WILL SWING A COLD FRONT
ACROSS THE REGION ON WEDNESDAY. DRY AND COLD WEATHER RETURNS FOR
THE END OF THE WEEK. ANOTHER COLD FRONT MOVES THROUGH ON SATURDAY.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...

7 PM UPDATE...SNOW HAS MOVED ACROSS THE REGION. LOWEST VSBYS ARE
ACROSS CONNECTICUT/RI/SOUTHEAST MASS. EXPECT THIS TO REMAIN IN
PLACE THROUGH MIDNIGHT BUT CAN/T RULE OUT A WOBBLE NORTH THAT
BRINGS BRIEFLY HEAVIER SNOW RATES NEAR THE MASS PIKE CORRIDOR.
NO SIGNIFICANT CHANGES MADE...THE 4 PM FORECAST HANDLES IT QUITE
WELL.

PREVIOUS DISCUSSION...
LOW PRESSURE EMERGING FROM THE MID ATLANTIC COASTLINE IS EXPECTED
TO PASS SOUTHEAST OF NANTUCKET TONIGHT...BRINGING A WIDESPREAD
SNOW TO SOUTHERN NEW ENGLAND. SURFACE OBS AS OF 21Z INDICATE THAT
SNOW HAS OVERSPREAD THE ENTIRE AREA. THE STRONGEST RADAR
RETURNS AT 21Z WERE NEAR THE SOUTH COAST OF CT INTO RI...AND TO
THE SOUTHWEST. THE BETTER FORCING FROM THIS EVENT IS EXPECTED TO OCCUR
TO THE SOUTH OF THE MA TURNPIKE. 12Z MODELS WERE IN DECENT
AGREEMENT ON PLACING THE HIGHEST QPF IN THAT AREA.

BECAUSE OF THE QUICK HITTING NATURE OF THIS SYSTEM WITH A SHORT
LIVED WINDOW FOR VERY STRONG LIFT/FORCING...CONTINUE TO THINK THAT
FOR MOST OF THE REGION WINTER WEATHER ADVISORY/S FOR 3 TO 6 INCHES
OF SNOW WILL COVER THIS EVENT. HOWEVER...GIVEN THERE IS NICE
OMEGA IN THE SNOW GROWTH REGION...WE MIGHT BE LOOKING AT SOME
DECENT RATIOS. SO WE STILL CAN NOT RULE OUT THE LOW RISK OF
REACHING WARNING AMOUNTS...ESPECIALLY ACROSS NORTHERN CT AND
NORTHWEST RI.

WE DID UPGRADED BLOCK ISLAND TO A WINTER STORM WARNING FOR THE
LATE AFTERNOON FORECAST PACKAGE. THERE MAY BE SOME MIXING WITH
RAIN IN THIS AREA AT TIMES.

EXPECT THIS TO BE A SNOW EVENT FOR THE VAST MAJORITY OF SOUTHERN
NEW ENGLAND. IT DOES BECOME A VERY CLOSE CALL NEAR THE SOUTH
COAST...BUT WERE LEANING TOWARDS IT STAYING MAINLY WET SNOW.
CONTINUED THE HIGH END WINTER WEATHER ADVISORY FOR THE CAPE
BECAUSE THEY MAY CHANGE TO RAIN FOR A TIME...ESPECIALLY EAST OF
HYANNIS. IF THE CHANGE OVER DOES NOT OCCUR...SNOWFALL TOTALS MAY
BE SOMEWHAT HIGHER. THE PRECIPITATION IS EXPECTED TO COME TO AN
END ACROSS THE MAJORITY OF THE AREA BY DAYBREAK MONDAY.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
MONDAY...
PRECIPITATION WILL HAVE LARGELY COME TO AN END FOR DAYBREAK MONDAY
WITH THE LOW PRESSURE RAPIDLY PULLING AWAY INTO THE CANADIAN
MARITIMES AND DRIER AIR/HIGH PRESSRUE MOVING IN FROM THE WEST.
INCREASING SUNSHINE EXPECTEED DURING THE DAY...WITH TEMPS TOPPING
OUT IN THE UPPER 20S TO MID 30S. HOWEVER AS WE GET TOWARDS
MIDDAY/AFTERNOON TIGHTENING GRADIENT WILL ALLOW NORTHWEST FLOW TO
BECOME BLUSTERY...WITH GUSTS OF 25 TO 30 MPH...25 TO 35 MPH ON THE
CAPE AND ISLANDS.

MONDAY NIGHT...
HIGH PRESSURE SETTLES OVER THE AREA WITH CLEAR SKIES EXPECTED.
GIVEN OUR SNOWPACK IN PLACE AND LIGHT WINDS...SHOULD BE ANOTHER
NIGHT FOR EXCELLENT RADIATIONAL COOLING. BECAUSE OF THIS DID
GENERALLY GO BELOW MODEL GUIDANCE FOR MIN TEMPS...LOOKING TO
ANTICIPATED SURFACE DEWPOINTS FOR A GUIDELINE ON HOW LOW WE CAN
GO. MAY SEE SOME SPOTS IN THE INTERIOR DROP BELOW ZERO.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...

BIG PICTURE... THE BROAD UPPER FLOW CONTINUES TO FEATURE A TROUGH
TRANSITING EAST ACROSS THE COUNTRY...REACHING THE EASTERN USA DURING
THE LATE WEEK AND LINGERING THROUGH THE WEEKEND. MEANWHILE AN UPPER
RIDGE SHIFTS FROM THE PACIFIC OCEAN BACK ASHORE ONTO THE WEST COAST.
CONTOUR HEIGHTS IN THE TROUGH ARE LOWEST THURSDAY-FRIDAY AND NEAR
NORMAL OVER THE WEEKEND. THIS MEANS A TREND TO COLDER TEMPS THURSDAY-
FRIDAY FOLLOWED BY A TREND CLOSER TO NORMAL OVER THE WEEKEND.

DAILIES...

TUESDAY... HIGH PRESSURE OVER THE REGION MOVES OFFSHORE BY AFTERNOON
WITH AIRFLOW SWINGING FROM NORTHWEST TO SOUTHWEST. THE SURFACE
AIRMASS STARTS OUT QUITE DRY WITH DEW POINTS IN THE SINGLE NUMBERS
BELOW ZERO TO START...CLIMBING TO 5-10 ABOVE BY EVENING. MODEL CROSS
SECTIONS SHOW INCREASING MOISTURE MORNING AND AFTERNOON ABOVE 700
MB. THIS SUGGESTS INCREASING MID AND HIGH CLOUDS WHILE DRY BENEATH.
LOW LEVEL JETS FROM THE CAROLINAS AND MIDWEST AND THE SURFACE
PRESSURE GRADIENT ALL SUGGEST THE INFLOW AND ISENTROPIC LIFT WILL
REMAIN TO OUR WEST THROUGH THE DAY...POSSIBLY ENTERING WESTERN MA/CT
AT OR AFTER 21Z. SO WE EXPECT INCREASING CLOUDS TUESDAY BUT
OTHERWISE DRY WEATHER THROUGH THE DAY. POSSIBLE LIGHT SNOW AROUND
THE EVENING RUSH HOUR IN THE CT RIVER VALLEY. TEMPS SHOULD REACH THE
MID 20S TO AROUND 30.

TUESDAY NIGHT-WEDNESDAY... NORTHERN AND SOUTHERN STREAM SHORTWAVES
MERGE OVER THE GREAT LAKES AND TRACK INTO CANADA. THIS BRINGS A MILD
FLOW OF AIR UP OVER NEW ENGLAND. THE LEADING EDGE OF THIS AIR
REACHES WESTERN SECTIONS TUESDAY EVENING AND EASTERN SECTIONS
TUESDAY NIGHT. TEMPERATURE PROFILES SUPPORT AN INITIAL PERIOD OF
SNOW CHANGING TO RAIN OR FREEZING RAIN OVERNIGHT. ACTUALLY...THE
MODELS MAY NOT BE HANDLING WELL THE CHILLING MASS OF SNOW AND COLD
GROUND /A.K.A. THE GIANT ICECUBE/ WHICH WOULD MEAN THE ACTUAL MAX
SFC TEMPS WILL BE COOLER THAN MODEL FORECASTS. TEMPERATURES AT 925
AND 950 MB WILL BE IN THE 30S...SO EXPECT SURFACE TEMPS NO HIGHER
THAN THE LOWER 40S.

THE SURFACE LOW PRESSURE AREA PASSES WELL NORTH OF NEW ENGLAND
WEDNESDAY AND SWINGS A COLD FRONT THROUGH THE REGION DURING THE
AFTERNOON OR EVENING. MOISTURE CROSS SECTIONS SHOW DECREASING RH IN
THE LIFT AND NUCLEATION ZONES ALOFT WEDNESDAY MORNING...SO THE TREND
THROUGH THE DAY SHOULD BE TO DIMINISHING POPS.

THURSDAY-FRIDAY... THE WEDNESDAY COLD FRONT WILL ALIGN WITH THE
UPPER FLOW AS IT MOVES SOUTH OF NEW ENGLAND...SLOWING ITS OFFSHORE
PROGRESS TO A CRAWL. MEANWHILE WE WILL BE UNDER THE RIGHT ENTRANCE
REGION OF THE SUPPORTING UPPER JET...A SOURCE OF UPPER VENTING. THIS
SHOULD SUPPORT LINGERING CLOUDS AND A CHANCE OF PCPN...WITH TEMPS
SUPPORTIVE OF SNOW. BEST CHANCE SOUTH COAST...LESSER CHANCE FARTHER
NORTH. THE JET AND SURFACE FRONT SWEEP OFFSHORE THURSDAY NIGHT. HIGH
PRESSURE THEN MOVES OVER THE EASTERN USA FOR FRIDAY. TEMPS ALOFT
SUPPORT MAX SFC TEMPS IN THE 20S.

SATURDAY-SUNDAY... ANOTHER NORTHERN STREAM SHORTWAVE AND COLD FRONT
SWINGS THROUGH THE FLOW SATURDAY. CROSS SECTIONS SHOW SOME MOISTURE
ALOFT BUT MOST OF IT IS CONCENTRATED TO OUR NORTH.  ALSO JUST
LIMITED LIFT TO WORK ON THAT MOISTURE. WE WILL HAVE 25-50 PCT SKY
COVER AND NIL POPS. HIGH PRESSURE THEN BUILDS FOR SUNDAY.

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...

TONIGHT...MODERATE CONFIDENCE. MVFR CIGS WITH PATCHES OF IFR
VALUES. VSBYS MOSTLY 1 TO 3 MILES WITH A ZONE FROM SOUTHERN CT
THROUGH RI AND SE MASS WHERE VSBYS ARE LIFR AT 1/2 MILE TO 1 MILE.
EXPECT THESE CONDITIONS TO LINGER THROUGH MIDNIGHT. THE ZONE OF
LOWER VSBYS AND SNOWFALL RATES COULD WOBBLE NORTH A FEW MILES AND
BRIEFLY APPROACH BOSTON BUT SHOULD PRIMARILY REMAIN TO THE SOUTH.

SOUTH FLOW BRINGS ENOUGH MILDER AIR NORTH TO MIX OR CHANGE THE
PCPN TO RAIN ON NANTUCKET AND PARTS OF THE OUTER CAPE. BULK OF THE
SNOW SHOULD ENDS 06Z WEST TO 10Z EAST /LATE TONIGHT AND EARLY
MONDAY/ MUCH OF THE REGION SHOULD IMPROVE TO VFR CONDITIONS BY
12-13Z MONDAY.

KBOS TAF...CONFIDENT IN OVERALL TRENDS BUT THERE IS UNCERTAINTY ON
TIMING. VSBYS BELOW 1 MILE SHOULD REMAIN TO THE SOUTH BUT COULD
BRIEFLY VISIT THE AIRPORT EARLY TONIGHT. THE BULK OF ACCUMULATING
SNOW IS EXPECTED BY MIDNIGHT.

KBDL TAF...CONFIDENT IN OVERALL TRENDS BUT THERE IS UNCERTAINTY ON
TIMING. BULK OF ACCUMULATING SNOW WITH IFR TO LIFR CONDITIONS
EXPECTED BY MIDNIGHT.

MONDAY AND MONDAY NIGHT...HIGH CONFIDENCE VFR. NORTHWEST WINDS
GUSTING TO 25 TO 30 MPH ACROSS MUCH OF THE AREA DURING MONDAY
AFTERNOON...25 TO 35 MPH GUSTS CAPE/ISLANDS. WINDS DIMINISHING
TOWARDS SUNSET.

OUTLOOK...TUESDAY THROUGH FRIDAY...

TUESDAY...MODERATE CONFIDENCE. VFR DURING THE DAY WITH INCREASING
SKY COVER. MVFR CIGS/VSBYS POSSIBLE LATE IN THE DAY CT RIVER VALLEY.

TUESDAY NIGHT-WEDNESDAY...MODERATE CONFIDENCE. CONDITIONS LOWERING
TO IFR/LIFR. INITIALLY SNOW BUT CHANGING TO SLEET/FREEZING RAIN
DURING THE NIGHT AND RAIN IN THE COASTAL PLAIN OVERNIGHT. PCPN
CHANGES TO RAIN ALL AREAS WEDNESDAY...BUT COLD SURFACES COULD
MAINTAIN A FREEZING RAIN ELEMENT WEDNESDAY MORNING. COLDER AIR MOVES
IN WEDNESDAY NIGHT CHANGING ANY RAIN TO SNOW.

THURSDAY...LOW CONFIDENCE. VFR NORTH OF A HFD-BOS LINE. MVFR CIGS
AND AREAS OF MVFR/IFR VSBYS IN SNOW...DIMINISHING BY EVENING.
NORTHWEST WINDS GUSTING TO 20 KNOTS.

FRIDAY...MODERATE CONFIDENCE. VFR.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...HIGH CONFIDENCE.

A WEAK WAVE OF LOW PRESSURE MOVES ACROSS THE WATERS TONIGHT.
THIS SYSTEM REALLY INTENSIFIES AS IT MOVES INTO THE CANADIAN
MARITIMES NEAR DAYBREAK MONDAY...SO WESTERLY WIND GUSTS MAY REACH
20 TO 25 KNOTS NEAR 12Z MONDAY. OTHERWISE...RAIN AND SNOW THIS
EVENING AND TONIGHT WILL REDUCE VISIBILITIES AT TIMES FOR
MARINERS.

MONDAY...AS THE LOW PRESSURE GOING INTO THE CANADIAN MARITIMES
INTENSFIES...INCREASING NORTHWEST WINDS ARE EXPECTED OVER THE
SOUTHERN NEW ENGLAND COASTAL WATERS...WITH GALE FORCE GUSTS
EXPECTED. GALE WARNINGS HAVE BEEN HOISTED FOR ALL COASTAL WATERS
FROM MIDDAY MONDAY INTO MONDAY NIGHT.

OUTLOOK...TUESDAY THROUGH FRIDAY..MODERATE CONFIDENCE.

TUESDAY... LINGERING 5 FOOT SEAS SOUTH AND EAST OF NANTUCKET IN THE
MORNING BUT DIMINISHING. NORTHWEST WINDS DIMINISHING FROM 20 KNOTS.
ANY SMALL CRAFT ADVISORY SHOULD END IN THE MORNING.

TUESDAY NIGHT-WEDNESDAY...SOUTH TO SOUTHWEST WINDS WILL INCREASE TO
20-25 KNOTS. SEAS WILL BUILD 6 TO 10 FEET ON THE OUTER WATERS AND ON
RI SOUND. REDUCED VSBYS...INITIALLY SNOW BUT CHANGING TO RAIN. A
SMALL CRAFT ADVISORY MAY BE NEEDED.

THURSDAY...NORTHWEST WIND GUSTING TO 25 KNOTS. SEAS 5 TO 8 FEET
MAINLY ON THE OUTER WATERS...DIMINISHING LATE. A SMALL CRAFT
ADVISORY MAY BE NEEDED.

FRIDAY... SHIFTING WINDS LESS THAN 20 KNOTS. SEAS LESS THAN 5 FEET.
QUIET WEATHER.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR CTZ002>004.
MA...WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR MAZ017>021.
     WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR MAZ002>016-
     022>024-026.
RI...WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR RIZ002>008.
     WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR RIZ001.
MARINE...GALE WARNING FROM 11 AM MONDAY TO 4 AM EST TUESDAY FOR ANZ231-
     232-250-251-254-255.
     GALE WARNING FROM 11 AM TO 11 PM EST MONDAY FOR ANZ233>235-237-
     256.
     GALE WARNING FROM 11 AM TO 8 PM EST MONDAY FOR ANZ230-236.

&&

$$
SYNOPSIS...WTB/NMB
NEAR TERM...WTB/NMB
SHORT TERM...NMB
LONG TERM...WTB
AVIATION...WTB/NMB
MARINE...WTB/NMB




000
FXUS61 KBOX 012346
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
646 PM EST SUN MAR 1 2015

.SYNOPSIS...
A FAST MOVING LOW PRESSURE SYSTEM WILL BRING ACCUMULATING SNOW
THIS EVENING AND TONIGHT WITH THE HIGHEST AMOUNTS EXPECTED SOUTH
OF THE MASSACHUSETTS TURNPIKE. HIGH PRESSURE BRINGS DRY COLD AIR
FOR THE EARLY WEEK. LOW PRESSURE FROM NORTHERN CANADA AND
ASSOCIATED LOW FORMING OVER THE PLAINS MONDAY WILL MERGE...THEN
PASS WEST AND NORTH OF NEW ENGLAND. THIS WILL SWING A COLD FRONT
ACROSS THE REGION ON WEDNESDAY. DRY AND COLD WEATHER RETURNS FOR
THE END OF THE WEEK. ANOTHER COLD FRONT MOVES THROUGH ON SATURDAY.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...

7 PM UPDATE...SNOW HAS MOVED ACROSS THE REGION. LOWEST VSBYS ARE
ACROSS CONNECTICUT/RI/SOUTHEAST MASS. EXPECT THIS TO REMAIN IN
PLACE THROUGH MIDNIGHT BUT CAN/T RULE OUT A WOBBLE NORTH THAT
BRINGS BRIEFLY HEAVIER SNOW RATES NEAR THE MASS PIKE CORRIDOR.
NO SIGNIFICANT CHANGES MADE...THE 4 PM FORECAST HANDLES IT QUITE
WELL.

PREVIOUS DISCUSSION...
LOW PRESSURE EMERGING FROM THE MID ATLANTIC COASTLINE IS EXPECTED
TO PASS SOUTHEAST OF NANTUCKET TONIGHT...BRINGING A WIDESPREAD
SNOW TO SOUTHERN NEW ENGLAND. SURFACE OBS AS OF 21Z INDICATE THAT
SNOW HAS OVERSPREAD THE ENTIRE AREA. THE STRONGEST RADAR
RETURNS AT 21Z WERE NEAR THE SOUTH COAST OF CT INTO RI...AND TO
THE SOUTHWEST. THE BETTER FORCING FROM THIS EVENT IS EXPECTED TO OCCUR
TO THE SOUTH OF THE MA TURNPIKE. 12Z MODELS WERE IN DECENT
AGREEMENT ON PLACING THE HIGHEST QPF IN THAT AREA.

BECAUSE OF THE QUICK HITTING NATURE OF THIS SYSTEM WITH A SHORT
LIVED WINDOW FOR VERY STRONG LIFT/FORCING...CONTINUE TO THINK THAT
FOR MOST OF THE REGION WINTER WEATHER ADVISORY/S FOR 3 TO 6 INCHES
OF SNOW WILL COVER THIS EVENT. HOWEVER...GIVEN THERE IS NICE
OMEGA IN THE SNOW GROWTH REGION...WE MIGHT BE LOOKING AT SOME
DECENT RATIOS. SO WE STILL CAN NOT RULE OUT THE LOW RISK OF
REACHING WARNING AMOUNTS...ESPECIALLY ACROSS NORTHERN CT AND
NORTHWEST RI.

WE DID UPGRADED BLOCK ISLAND TO A WINTER STORM WARNING FOR THE
LATE AFTERNOON FORECAST PACKAGE. THERE MAY BE SOME MIXING WITH
RAIN IN THIS AREA AT TIMES.

EXPECT THIS TO BE A SNOW EVENT FOR THE VAST MAJORITY OF SOUTHERN
NEW ENGLAND. IT DOES BECOME A VERY CLOSE CALL NEAR THE SOUTH
COAST...BUT WERE LEANING TOWARDS IT STAYING MAINLY WET SNOW.
CONTINUED THE HIGH END WINTER WEATHER ADVISORY FOR THE CAPE
BECAUSE THEY MAY CHANGE TO RAIN FOR A TIME...ESPECIALLY EAST OF
HYANNIS. IF THE CHANGE OVER DOES NOT OCCUR...SNOWFALL TOTALS MAY
BE SOMEWHAT HIGHER. THE PRECIPITATION IS EXPECTED TO COME TO AN
END ACROSS THE MAJORITY OF THE AREA BY DAYBREAK MONDAY.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
MONDAY...
PRECIPITATION WILL HAVE LARGELY COME TO AN END FOR DAYBREAK MONDAY
WITH THE LOW PRESSURE RAPIDLY PULLING AWAY INTO THE CANADIAN
MARITIMES AND DRIER AIR/HIGH PRESSRUE MOVING IN FROM THE WEST.
INCREASING SUNSHINE EXPECTEED DURING THE DAY...WITH TEMPS TOPPING
OUT IN THE UPPER 20S TO MID 30S. HOWEVER AS WE GET TOWARDS
MIDDAY/AFTERNOON TIGHTENING GRADIENT WILL ALLOW NORTHWEST FLOW TO
BECOME BLUSTERY...WITH GUSTS OF 25 TO 30 MPH...25 TO 35 MPH ON THE
CAPE AND ISLANDS.

MONDAY NIGHT...
HIGH PRESSURE SETTLES OVER THE AREA WITH CLEAR SKIES EXPECTED.
GIVEN OUR SNOWPACK IN PLACE AND LIGHT WINDS...SHOULD BE ANOTHER
NIGHT FOR EXCELLENT RADIATIONAL COOLING. BECAUSE OF THIS DID
GENERALLY GO BELOW MODEL GUIDANCE FOR MIN TEMPS...LOOKING TO
ANTICIPATED SURFACE DEWPOINTS FOR A GUIDELINE ON HOW LOW WE CAN
GO. MAY SEE SOME SPOTS IN THE INTERIOR DROP BELOW ZERO.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...

BIG PICTURE... THE BROAD UPPER FLOW CONTINUES TO FEATURE A TROUGH
TRANSITING EAST ACROSS THE COUNTRY...REACHING THE EASTERN USA DURING
THE LATE WEEK AND LINGERING THROUGH THE WEEKEND. MEANWHILE AN UPPER
RIDGE SHIFTS FROM THE PACIFIC OCEAN BACK ASHORE ONTO THE WEST COAST.
CONTOUR HEIGHTS IN THE TROUGH ARE LOWEST THURSDAY-FRIDAY AND NEAR
NORMAL OVER THE WEEKEND. THIS MEANS A TREND TO COLDER TEMPS THURSDAY-
FRIDAY FOLLOWED BY A TREND CLOSER TO NORMAL OVER THE WEEKEND.

DAILIES...

TUESDAY... HIGH PRESSURE OVER THE REGION MOVES OFFSHORE BY AFTERNOON
WITH AIRFLOW SWINGING FROM NORTHWEST TO SOUTHWEST. THE SURFACE
AIRMASS STARTS OUT QUITE DRY WITH DEW POINTS IN THE SINGLE NUMBERS
BELOW ZERO TO START...CLIMBING TO 5-10 ABOVE BY EVENING. MODEL CROSS
SECTIONS SHOW INCREASING MOISTURE MORNING AND AFTERNOON ABOVE 700
MB. THIS SUGGESTS INCREASING MID AND HIGH CLOUDS WHILE DRY BENEATH.
LOW LEVEL JETS FROM THE CAROLINAS AND MIDWEST AND THE SURFACE
PRESSURE GRADIENT ALL SUGGEST THE INFLOW AND ISENTROPIC LIFT WILL
REMAIN TO OUR WEST THROUGH THE DAY...POSSIBLY ENTERING WESTERN MA/CT
AT OR AFTER 21Z. SO WE EXPECT INCREASING CLOUDS TUESDAY BUT
OTHERWISE DRY WEATHER THROUGH THE DAY. POSSIBLE LIGHT SNOW AROUND
THE EVENING RUSH HOUR IN THE CT RIVER VALLEY. TEMPS SHOULD REACH THE
MID 20S TO AROUND 30.

TUESDAY NIGHT-WEDNESDAY... NORTHERN AND SOUTHERN STREAM SHORTWAVES
MERGE OVER THE GREAT LAKES AND TRACK INTO CANADA. THIS BRINGS A MILD
FLOW OF AIR UP OVER NEW ENGLAND. THE LEADING EDGE OF THIS AIR
REACHES WESTERN SECTIONS TUESDAY EVENING AND EASTERN SECTIONS
TUESDAY NIGHT. TEMPERATURE PROFILES SUPPORT AN INITIAL PERIOD OF
SNOW CHANGING TO RAIN OR FREEZING RAIN OVERNIGHT. ACTUALLY...THE
MODELS MAY NOT BE HANDLING WELL THE CHILLING MASS OF SNOW AND COLD
GROUND /A.K.A. THE GIANT ICECUBE/ WHICH WOULD MEAN THE ACTUAL MAX
SFC TEMPS WILL BE COOLER THAN MODEL FORECASTS. TEMPERATURES AT 925
AND 950 MB WILL BE IN THE 30S...SO EXPECT SURFACE TEMPS NO HIGHER
THAN THE LOWER 40S.

THE SURFACE LOW PRESSURE AREA PASSES WELL NORTH OF NEW ENGLAND
WEDNESDAY AND SWINGS A COLD FRONT THROUGH THE REGION DURING THE
AFTERNOON OR EVENING. MOISTURE CROSS SECTIONS SHOW DECREASING RH IN
THE LIFT AND NUCLEATION ZONES ALOFT WEDNESDAY MORNING...SO THE TREND
THROUGH THE DAY SHOULD BE TO DIMINISHING POPS.

THURSDAY-FRIDAY... THE WEDNESDAY COLD FRONT WILL ALIGN WITH THE
UPPER FLOW AS IT MOVES SOUTH OF NEW ENGLAND...SLOWING ITS OFFSHORE
PROGRESS TO A CRAWL. MEANWHILE WE WILL BE UNDER THE RIGHT ENTRANCE
REGION OF THE SUPPORTING UPPER JET...A SOURCE OF UPPER VENTING. THIS
SHOULD SUPPORT LINGERING CLOUDS AND A CHANCE OF PCPN...WITH TEMPS
SUPPORTIVE OF SNOW. BEST CHANCE SOUTH COAST...LESSER CHANCE FARTHER
NORTH. THE JET AND SURFACE FRONT SWEEP OFFSHORE THURSDAY NIGHT. HIGH
PRESSURE THEN MOVES OVER THE EASTERN USA FOR FRIDAY. TEMPS ALOFT
SUPPORT MAX SFC TEMPS IN THE 20S.

SATURDAY-SUNDAY... ANOTHER NORTHERN STREAM SHORTWAVE AND COLD FRONT
SWINGS THROUGH THE FLOW SATURDAY. CROSS SECTIONS SHOW SOME MOISTURE
ALOFT BUT MOST OF IT IS CONCENTRATED TO OUR NORTH.  ALSO JUST
LIMITED LIFT TO WORK ON THAT MOISTURE. WE WILL HAVE 25-50 PCT SKY
COVER AND NIL POPS. HIGH PRESSURE THEN BUILDS FOR SUNDAY.

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...

TONIGHT...MODERATE CONFIDENCE. MVFR CIGS WITH PATCHES OF IFR
VALUES. VSBYS MOSTLY 1 TO 3 MILES WITH A ZONE FROM SOUTHERN CT
THROUGH RI AND SE MASS WHERE VSBYS ARE LIFR AT 1/2 MILE TO 1 MILE.
EXPECT THESE CONDITIONS TO LINGER THROUGH MIDNIGHT. THE ZONE OF
LOWER VSBYS AND SNOWFALL RATES COULD WOBBLE NORTH A FEW MILES AND
BRIEFLY APPROACH BOSTON BUT SHOULD PRIMARILY REMAIN TO THE SOUTH.

SOUTH FLOW BRINGS ENOUGH MILDER AIR NORTH TO MIX OR CHANGE THE
PCPN TO RAIN ON NANTUCKET AND PARTS OF THE OUTER CAPE. BULK OF THE
SNOW SHOULD ENDS 06Z WEST TO 10Z EAST /LATE TONIGHT AND EARLY
MONDAY/ MUCH OF THE REGION SHOULD IMPROVE TO VFR CONDITIONS BY
12-13Z MONDAY.

KBOS TAF...CONFIDENT IN OVERALL TRENDS BUT THERE IS UNCERTAINTY ON
TIMING. VSBYS BELOW 1 MILE SHOULD REMAIN TO THE SOUTH BUT COULD
BRIEFLY VISIT THE AIRPORT EARLY TONIGHT. THE BULK OF ACCUMULATING
SNOW IS EXPECTED BY MIDNIGHT.

KBDL TAF...CONFIDENT IN OVERALL TRENDS BUT THERE IS UNCERTAINTY ON
TIMING. BULK OF ACCUMULATING SNOW WITH IFR TO LIFR CONDITIONS
EXPECTED BY MIDNIGHT.

MONDAY AND MONDAY NIGHT...HIGH CONFIDENCE VFR. NORTHWEST WINDS
GUSTING TO 25 TO 30 MPH ACROSS MUCH OF THE AREA DURING MONDAY
AFTERNOON...25 TO 35 MPH GUSTS CAPE/ISLANDS. WINDS DIMINISHING
TOWARDS SUNSET.

OUTLOOK...TUESDAY THROUGH FRIDAY...

TUESDAY...MODERATE CONFIDENCE. VFR DURING THE DAY WITH INCREASING
SKY COVER. MVFR CIGS/VSBYS POSSIBLE LATE IN THE DAY CT RIVER VALLEY.

TUESDAY NIGHT-WEDNESDAY...MODERATE CONFIDENCE. CONDITIONS LOWERING
TO IFR/LIFR. INITIALLY SNOW BUT CHANGING TO SLEET/FREEZING RAIN
DURING THE NIGHT AND RAIN IN THE COASTAL PLAIN OVERNIGHT. PCPN
CHANGES TO RAIN ALL AREAS WEDNESDAY...BUT COLD SURFACES COULD
MAINTAIN A FREEZING RAIN ELEMENT WEDNESDAY MORNING. COLDER AIR MOVES
IN WEDNESDAY NIGHT CHANGING ANY RAIN TO SNOW.

THURSDAY...LOW CONFIDENCE. VFR NORTH OF A HFD-BOS LINE. MVFR CIGS
AND AREAS OF MVFR/IFR VSBYS IN SNOW...DIMINISHING BY EVENING.
NORTHWEST WINDS GUSTING TO 20 KNOTS.

FRIDAY...MODERATE CONFIDENCE. VFR.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...HIGH CONFIDENCE.

A WEAK WAVE OF LOW PRESSURE MOVES ACROSS THE WATERS TONIGHT.
THIS SYSTEM REALLY INTENSIFIES AS IT MOVES INTO THE CANADIAN
MARITIMES NEAR DAYBREAK MONDAY...SO WESTERLY WIND GUSTS MAY REACH
20 TO 25 KNOTS NEAR 12Z MONDAY. OTHERWISE...RAIN AND SNOW THIS
EVENING AND TONIGHT WILL REDUCE VISIBILITIES AT TIMES FOR
MARINERS.

MONDAY...AS THE LOW PRESSURE GOING INTO THE CANADIAN MARITIMES
INTENSFIES...INCREASING NORTHWEST WINDS ARE EXPECTED OVER THE
SOUTHERN NEW ENGLAND COASTAL WATERS...WITH GALE FORCE GUSTS
EXPECTED. GALE WARNINGS HAVE BEEN HOISTED FOR ALL COASTAL WATERS
FROM MIDDAY MONDAY INTO MONDAY NIGHT.

OUTLOOK...TUESDAY THROUGH FRIDAY..MODERATE CONFIDENCE.

TUESDAY... LINGERING 5 FOOT SEAS SOUTH AND EAST OF NANTUCKET IN THE
MORNING BUT DIMINISHING. NORTHWEST WINDS DIMINISHING FROM 20 KNOTS.
ANY SMALL CRAFT ADVISORY SHOULD END IN THE MORNING.

TUESDAY NIGHT-WEDNESDAY...SOUTH TO SOUTHWEST WINDS WILL INCREASE TO
20-25 KNOTS. SEAS WILL BUILD 6 TO 10 FEET ON THE OUTER WATERS AND ON
RI SOUND. REDUCED VSBYS...INITIALLY SNOW BUT CHANGING TO RAIN. A
SMALL CRAFT ADVISORY MAY BE NEEDED.

THURSDAY...NORTHWEST WIND GUSTING TO 25 KNOTS. SEAS 5 TO 8 FEET
MAINLY ON THE OUTER WATERS...DIMINISHING LATE. A SMALL CRAFT
ADVISORY MAY BE NEEDED.

FRIDAY... SHIFTING WINDS LESS THAN 20 KNOTS. SEAS LESS THAN 5 FEET.
QUIET WEATHER.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR CTZ002>004.
MA...WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR MAZ017>021.
     WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR MAZ002>016-
     022>024-026.
RI...WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR RIZ002>008.
     WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR RIZ001.
MARINE...GALE WARNING FROM 11 AM MONDAY TO 4 AM EST TUESDAY FOR ANZ231-
     232-250-251-254-255.
     GALE WARNING FROM 11 AM TO 11 PM EST MONDAY FOR ANZ233>235-237-
     256.
     GALE WARNING FROM 11 AM TO 8 PM EST MONDAY FOR ANZ230-236.

&&

$$
SYNOPSIS...WTB/NMB
NEAR TERM...WTB/NMB
SHORT TERM...NMB
LONG TERM...WTB
AVIATION...WTB/NMB
MARINE...WTB/NMB



000
FXUS61 KBOX 012346
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
646 PM EST SUN MAR 1 2015

.SYNOPSIS...
A FAST MOVING LOW PRESSURE SYSTEM WILL BRING ACCUMULATING SNOW
THIS EVENING AND TONIGHT WITH THE HIGHEST AMOUNTS EXPECTED SOUTH
OF THE MASSACHUSETTS TURNPIKE. HIGH PRESSURE BRINGS DRY COLD AIR
FOR THE EARLY WEEK. LOW PRESSURE FROM NORTHERN CANADA AND
ASSOCIATED LOW FORMING OVER THE PLAINS MONDAY WILL MERGE...THEN
PASS WEST AND NORTH OF NEW ENGLAND. THIS WILL SWING A COLD FRONT
ACROSS THE REGION ON WEDNESDAY. DRY AND COLD WEATHER RETURNS FOR
THE END OF THE WEEK. ANOTHER COLD FRONT MOVES THROUGH ON SATURDAY.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...

7 PM UPDATE...SNOW HAS MOVED ACROSS THE REGION. LOWEST VSBYS ARE
ACROSS CONNECTICUT/RI/SOUTHEAST MASS. EXPECT THIS TO REMAIN IN
PLACE THROUGH MIDNIGHT BUT CAN/T RULE OUT A WOBBLE NORTH THAT
BRINGS BRIEFLY HEAVIER SNOW RATES NEAR THE MASS PIKE CORRIDOR.
NO SIGNIFICANT CHANGES MADE...THE 4 PM FORECAST HANDLES IT QUITE
WELL.

PREVIOUS DISCUSSION...
LOW PRESSURE EMERGING FROM THE MID ATLANTIC COASTLINE IS EXPECTED
TO PASS SOUTHEAST OF NANTUCKET TONIGHT...BRINGING A WIDESPREAD
SNOW TO SOUTHERN NEW ENGLAND. SURFACE OBS AS OF 21Z INDICATE THAT
SNOW HAS OVERSPREAD THE ENTIRE AREA. THE STRONGEST RADAR
RETURNS AT 21Z WERE NEAR THE SOUTH COAST OF CT INTO RI...AND TO
THE SOUTHWEST. THE BETTER FORCING FROM THIS EVENT IS EXPECTED TO OCCUR
TO THE SOUTH OF THE MA TURNPIKE. 12Z MODELS WERE IN DECENT
AGREEMENT ON PLACING THE HIGHEST QPF IN THAT AREA.

BECAUSE OF THE QUICK HITTING NATURE OF THIS SYSTEM WITH A SHORT
LIVED WINDOW FOR VERY STRONG LIFT/FORCING...CONTINUE TO THINK THAT
FOR MOST OF THE REGION WINTER WEATHER ADVISORY/S FOR 3 TO 6 INCHES
OF SNOW WILL COVER THIS EVENT. HOWEVER...GIVEN THERE IS NICE
OMEGA IN THE SNOW GROWTH REGION...WE MIGHT BE LOOKING AT SOME
DECENT RATIOS. SO WE STILL CAN NOT RULE OUT THE LOW RISK OF
REACHING WARNING AMOUNTS...ESPECIALLY ACROSS NORTHERN CT AND
NORTHWEST RI.

WE DID UPGRADED BLOCK ISLAND TO A WINTER STORM WARNING FOR THE
LATE AFTERNOON FORECAST PACKAGE. THERE MAY BE SOME MIXING WITH
RAIN IN THIS AREA AT TIMES.

EXPECT THIS TO BE A SNOW EVENT FOR THE VAST MAJORITY OF SOUTHERN
NEW ENGLAND. IT DOES BECOME A VERY CLOSE CALL NEAR THE SOUTH
COAST...BUT WERE LEANING TOWARDS IT STAYING MAINLY WET SNOW.
CONTINUED THE HIGH END WINTER WEATHER ADVISORY FOR THE CAPE
BECAUSE THEY MAY CHANGE TO RAIN FOR A TIME...ESPECIALLY EAST OF
HYANNIS. IF THE CHANGE OVER DOES NOT OCCUR...SNOWFALL TOTALS MAY
BE SOMEWHAT HIGHER. THE PRECIPITATION IS EXPECTED TO COME TO AN
END ACROSS THE MAJORITY OF THE AREA BY DAYBREAK MONDAY.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
MONDAY...
PRECIPITATION WILL HAVE LARGELY COME TO AN END FOR DAYBREAK MONDAY
WITH THE LOW PRESSURE RAPIDLY PULLING AWAY INTO THE CANADIAN
MARITIMES AND DRIER AIR/HIGH PRESSRUE MOVING IN FROM THE WEST.
INCREASING SUNSHINE EXPECTEED DURING THE DAY...WITH TEMPS TOPPING
OUT IN THE UPPER 20S TO MID 30S. HOWEVER AS WE GET TOWARDS
MIDDAY/AFTERNOON TIGHTENING GRADIENT WILL ALLOW NORTHWEST FLOW TO
BECOME BLUSTERY...WITH GUSTS OF 25 TO 30 MPH...25 TO 35 MPH ON THE
CAPE AND ISLANDS.

MONDAY NIGHT...
HIGH PRESSURE SETTLES OVER THE AREA WITH CLEAR SKIES EXPECTED.
GIVEN OUR SNOWPACK IN PLACE AND LIGHT WINDS...SHOULD BE ANOTHER
NIGHT FOR EXCELLENT RADIATIONAL COOLING. BECAUSE OF THIS DID
GENERALLY GO BELOW MODEL GUIDANCE FOR MIN TEMPS...LOOKING TO
ANTICIPATED SURFACE DEWPOINTS FOR A GUIDELINE ON HOW LOW WE CAN
GO. MAY SEE SOME SPOTS IN THE INTERIOR DROP BELOW ZERO.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...

BIG PICTURE... THE BROAD UPPER FLOW CONTINUES TO FEATURE A TROUGH
TRANSITING EAST ACROSS THE COUNTRY...REACHING THE EASTERN USA DURING
THE LATE WEEK AND LINGERING THROUGH THE WEEKEND. MEANWHILE AN UPPER
RIDGE SHIFTS FROM THE PACIFIC OCEAN BACK ASHORE ONTO THE WEST COAST.
CONTOUR HEIGHTS IN THE TROUGH ARE LOWEST THURSDAY-FRIDAY AND NEAR
NORMAL OVER THE WEEKEND. THIS MEANS A TREND TO COLDER TEMPS THURSDAY-
FRIDAY FOLLOWED BY A TREND CLOSER TO NORMAL OVER THE WEEKEND.

DAILIES...

TUESDAY... HIGH PRESSURE OVER THE REGION MOVES OFFSHORE BY AFTERNOON
WITH AIRFLOW SWINGING FROM NORTHWEST TO SOUTHWEST. THE SURFACE
AIRMASS STARTS OUT QUITE DRY WITH DEW POINTS IN THE SINGLE NUMBERS
BELOW ZERO TO START...CLIMBING TO 5-10 ABOVE BY EVENING. MODEL CROSS
SECTIONS SHOW INCREASING MOISTURE MORNING AND AFTERNOON ABOVE 700
MB. THIS SUGGESTS INCREASING MID AND HIGH CLOUDS WHILE DRY BENEATH.
LOW LEVEL JETS FROM THE CAROLINAS AND MIDWEST AND THE SURFACE
PRESSURE GRADIENT ALL SUGGEST THE INFLOW AND ISENTROPIC LIFT WILL
REMAIN TO OUR WEST THROUGH THE DAY...POSSIBLY ENTERING WESTERN MA/CT
AT OR AFTER 21Z. SO WE EXPECT INCREASING CLOUDS TUESDAY BUT
OTHERWISE DRY WEATHER THROUGH THE DAY. POSSIBLE LIGHT SNOW AROUND
THE EVENING RUSH HOUR IN THE CT RIVER VALLEY. TEMPS SHOULD REACH THE
MID 20S TO AROUND 30.

TUESDAY NIGHT-WEDNESDAY... NORTHERN AND SOUTHERN STREAM SHORTWAVES
MERGE OVER THE GREAT LAKES AND TRACK INTO CANADA. THIS BRINGS A MILD
FLOW OF AIR UP OVER NEW ENGLAND. THE LEADING EDGE OF THIS AIR
REACHES WESTERN SECTIONS TUESDAY EVENING AND EASTERN SECTIONS
TUESDAY NIGHT. TEMPERATURE PROFILES SUPPORT AN INITIAL PERIOD OF
SNOW CHANGING TO RAIN OR FREEZING RAIN OVERNIGHT. ACTUALLY...THE
MODELS MAY NOT BE HANDLING WELL THE CHILLING MASS OF SNOW AND COLD
GROUND /A.K.A. THE GIANT ICECUBE/ WHICH WOULD MEAN THE ACTUAL MAX
SFC TEMPS WILL BE COOLER THAN MODEL FORECASTS. TEMPERATURES AT 925
AND 950 MB WILL BE IN THE 30S...SO EXPECT SURFACE TEMPS NO HIGHER
THAN THE LOWER 40S.

THE SURFACE LOW PRESSURE AREA PASSES WELL NORTH OF NEW ENGLAND
WEDNESDAY AND SWINGS A COLD FRONT THROUGH THE REGION DURING THE
AFTERNOON OR EVENING. MOISTURE CROSS SECTIONS SHOW DECREASING RH IN
THE LIFT AND NUCLEATION ZONES ALOFT WEDNESDAY MORNING...SO THE TREND
THROUGH THE DAY SHOULD BE TO DIMINISHING POPS.

THURSDAY-FRIDAY... THE WEDNESDAY COLD FRONT WILL ALIGN WITH THE
UPPER FLOW AS IT MOVES SOUTH OF NEW ENGLAND...SLOWING ITS OFFSHORE
PROGRESS TO A CRAWL. MEANWHILE WE WILL BE UNDER THE RIGHT ENTRANCE
REGION OF THE SUPPORTING UPPER JET...A SOURCE OF UPPER VENTING. THIS
SHOULD SUPPORT LINGERING CLOUDS AND A CHANCE OF PCPN...WITH TEMPS
SUPPORTIVE OF SNOW. BEST CHANCE SOUTH COAST...LESSER CHANCE FARTHER
NORTH. THE JET AND SURFACE FRONT SWEEP OFFSHORE THURSDAY NIGHT. HIGH
PRESSURE THEN MOVES OVER THE EASTERN USA FOR FRIDAY. TEMPS ALOFT
SUPPORT MAX SFC TEMPS IN THE 20S.

SATURDAY-SUNDAY... ANOTHER NORTHERN STREAM SHORTWAVE AND COLD FRONT
SWINGS THROUGH THE FLOW SATURDAY. CROSS SECTIONS SHOW SOME MOISTURE
ALOFT BUT MOST OF IT IS CONCENTRATED TO OUR NORTH.  ALSO JUST
LIMITED LIFT TO WORK ON THAT MOISTURE. WE WILL HAVE 25-50 PCT SKY
COVER AND NIL POPS. HIGH PRESSURE THEN BUILDS FOR SUNDAY.

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...

TONIGHT...MODERATE CONFIDENCE. MVFR CIGS WITH PATCHES OF IFR
VALUES. VSBYS MOSTLY 1 TO 3 MILES WITH A ZONE FROM SOUTHERN CT
THROUGH RI AND SE MASS WHERE VSBYS ARE LIFR AT 1/2 MILE TO 1 MILE.
EXPECT THESE CONDITIONS TO LINGER THROUGH MIDNIGHT. THE ZONE OF
LOWER VSBYS AND SNOWFALL RATES COULD WOBBLE NORTH A FEW MILES AND
BRIEFLY APPROACH BOSTON BUT SHOULD PRIMARILY REMAIN TO THE SOUTH.

SOUTH FLOW BRINGS ENOUGH MILDER AIR NORTH TO MIX OR CHANGE THE
PCPN TO RAIN ON NANTUCKET AND PARTS OF THE OUTER CAPE. BULK OF THE
SNOW SHOULD ENDS 06Z WEST TO 10Z EAST /LATE TONIGHT AND EARLY
MONDAY/ MUCH OF THE REGION SHOULD IMPROVE TO VFR CONDITIONS BY
12-13Z MONDAY.

KBOS TAF...CONFIDENT IN OVERALL TRENDS BUT THERE IS UNCERTAINTY ON
TIMING. VSBYS BELOW 1 MILE SHOULD REMAIN TO THE SOUTH BUT COULD
BRIEFLY VISIT THE AIRPORT EARLY TONIGHT. THE BULK OF ACCUMULATING
SNOW IS EXPECTED BY MIDNIGHT.

KBDL TAF...CONFIDENT IN OVERALL TRENDS BUT THERE IS UNCERTAINTY ON
TIMING. BULK OF ACCUMULATING SNOW WITH IFR TO LIFR CONDITIONS
EXPECTED BY MIDNIGHT.

MONDAY AND MONDAY NIGHT...HIGH CONFIDENCE VFR. NORTHWEST WINDS
GUSTING TO 25 TO 30 MPH ACROSS MUCH OF THE AREA DURING MONDAY
AFTERNOON...25 TO 35 MPH GUSTS CAPE/ISLANDS. WINDS DIMINISHING
TOWARDS SUNSET.

OUTLOOK...TUESDAY THROUGH FRIDAY...

TUESDAY...MODERATE CONFIDENCE. VFR DURING THE DAY WITH INCREASING
SKY COVER. MVFR CIGS/VSBYS POSSIBLE LATE IN THE DAY CT RIVER VALLEY.

TUESDAY NIGHT-WEDNESDAY...MODERATE CONFIDENCE. CONDITIONS LOWERING
TO IFR/LIFR. INITIALLY SNOW BUT CHANGING TO SLEET/FREEZING RAIN
DURING THE NIGHT AND RAIN IN THE COASTAL PLAIN OVERNIGHT. PCPN
CHANGES TO RAIN ALL AREAS WEDNESDAY...BUT COLD SURFACES COULD
MAINTAIN A FREEZING RAIN ELEMENT WEDNESDAY MORNING. COLDER AIR MOVES
IN WEDNESDAY NIGHT CHANGING ANY RAIN TO SNOW.

THURSDAY...LOW CONFIDENCE. VFR NORTH OF A HFD-BOS LINE. MVFR CIGS
AND AREAS OF MVFR/IFR VSBYS IN SNOW...DIMINISHING BY EVENING.
NORTHWEST WINDS GUSTING TO 20 KNOTS.

FRIDAY...MODERATE CONFIDENCE. VFR.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...HIGH CONFIDENCE.

A WEAK WAVE OF LOW PRESSURE MOVES ACROSS THE WATERS TONIGHT.
THIS SYSTEM REALLY INTENSIFIES AS IT MOVES INTO THE CANADIAN
MARITIMES NEAR DAYBREAK MONDAY...SO WESTERLY WIND GUSTS MAY REACH
20 TO 25 KNOTS NEAR 12Z MONDAY. OTHERWISE...RAIN AND SNOW THIS
EVENING AND TONIGHT WILL REDUCE VISIBILITIES AT TIMES FOR
MARINERS.

MONDAY...AS THE LOW PRESSURE GOING INTO THE CANADIAN MARITIMES
INTENSFIES...INCREASING NORTHWEST WINDS ARE EXPECTED OVER THE
SOUTHERN NEW ENGLAND COASTAL WATERS...WITH GALE FORCE GUSTS
EXPECTED. GALE WARNINGS HAVE BEEN HOISTED FOR ALL COASTAL WATERS
FROM MIDDAY MONDAY INTO MONDAY NIGHT.

OUTLOOK...TUESDAY THROUGH FRIDAY..MODERATE CONFIDENCE.

TUESDAY... LINGERING 5 FOOT SEAS SOUTH AND EAST OF NANTUCKET IN THE
MORNING BUT DIMINISHING. NORTHWEST WINDS DIMINISHING FROM 20 KNOTS.
ANY SMALL CRAFT ADVISORY SHOULD END IN THE MORNING.

TUESDAY NIGHT-WEDNESDAY...SOUTH TO SOUTHWEST WINDS WILL INCREASE TO
20-25 KNOTS. SEAS WILL BUILD 6 TO 10 FEET ON THE OUTER WATERS AND ON
RI SOUND. REDUCED VSBYS...INITIALLY SNOW BUT CHANGING TO RAIN. A
SMALL CRAFT ADVISORY MAY BE NEEDED.

THURSDAY...NORTHWEST WIND GUSTING TO 25 KNOTS. SEAS 5 TO 8 FEET
MAINLY ON THE OUTER WATERS...DIMINISHING LATE. A SMALL CRAFT
ADVISORY MAY BE NEEDED.

FRIDAY... SHIFTING WINDS LESS THAN 20 KNOTS. SEAS LESS THAN 5 FEET.
QUIET WEATHER.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR CTZ002>004.
MA...WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR MAZ017>021.
     WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR MAZ002>016-
     022>024-026.
RI...WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR RIZ002>008.
     WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR RIZ001.
MARINE...GALE WARNING FROM 11 AM MONDAY TO 4 AM EST TUESDAY FOR ANZ231-
     232-250-251-254-255.
     GALE WARNING FROM 11 AM TO 11 PM EST MONDAY FOR ANZ233>235-237-
     256.
     GALE WARNING FROM 11 AM TO 8 PM EST MONDAY FOR ANZ230-236.

&&

$$
SYNOPSIS...WTB/NMB
NEAR TERM...WTB/NMB
SHORT TERM...NMB
LONG TERM...WTB
AVIATION...WTB/NMB
MARINE...WTB/NMB




000
FXUS61 KBOX 012346
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
646 PM EST SUN MAR 1 2015

.SYNOPSIS...
A FAST MOVING LOW PRESSURE SYSTEM WILL BRING ACCUMULATING SNOW
THIS EVENING AND TONIGHT WITH THE HIGHEST AMOUNTS EXPECTED SOUTH
OF THE MASSACHUSETTS TURNPIKE. HIGH PRESSURE BRINGS DRY COLD AIR
FOR THE EARLY WEEK. LOW PRESSURE FROM NORTHERN CANADA AND
ASSOCIATED LOW FORMING OVER THE PLAINS MONDAY WILL MERGE...THEN
PASS WEST AND NORTH OF NEW ENGLAND. THIS WILL SWING A COLD FRONT
ACROSS THE REGION ON WEDNESDAY. DRY AND COLD WEATHER RETURNS FOR
THE END OF THE WEEK. ANOTHER COLD FRONT MOVES THROUGH ON SATURDAY.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...

7 PM UPDATE...SNOW HAS MOVED ACROSS THE REGION. LOWEST VSBYS ARE
ACROSS CONNECTICUT/RI/SOUTHEAST MASS. EXPECT THIS TO REMAIN IN
PLACE THROUGH MIDNIGHT BUT CAN/T RULE OUT A WOBBLE NORTH THAT
BRINGS BRIEFLY HEAVIER SNOW RATES NEAR THE MASS PIKE CORRIDOR.
NO SIGNIFICANT CHANGES MADE...THE 4 PM FORECAST HANDLES IT QUITE
WELL.

PREVIOUS DISCUSSION...
LOW PRESSURE EMERGING FROM THE MID ATLANTIC COASTLINE IS EXPECTED
TO PASS SOUTHEAST OF NANTUCKET TONIGHT...BRINGING A WIDESPREAD
SNOW TO SOUTHERN NEW ENGLAND. SURFACE OBS AS OF 21Z INDICATE THAT
SNOW HAS OVERSPREAD THE ENTIRE AREA. THE STRONGEST RADAR
RETURNS AT 21Z WERE NEAR THE SOUTH COAST OF CT INTO RI...AND TO
THE SOUTHWEST. THE BETTER FORCING FROM THIS EVENT IS EXPECTED TO OCCUR
TO THE SOUTH OF THE MA TURNPIKE. 12Z MODELS WERE IN DECENT
AGREEMENT ON PLACING THE HIGHEST QPF IN THAT AREA.

BECAUSE OF THE QUICK HITTING NATURE OF THIS SYSTEM WITH A SHORT
LIVED WINDOW FOR VERY STRONG LIFT/FORCING...CONTINUE TO THINK THAT
FOR MOST OF THE REGION WINTER WEATHER ADVISORY/S FOR 3 TO 6 INCHES
OF SNOW WILL COVER THIS EVENT. HOWEVER...GIVEN THERE IS NICE
OMEGA IN THE SNOW GROWTH REGION...WE MIGHT BE LOOKING AT SOME
DECENT RATIOS. SO WE STILL CAN NOT RULE OUT THE LOW RISK OF
REACHING WARNING AMOUNTS...ESPECIALLY ACROSS NORTHERN CT AND
NORTHWEST RI.

WE DID UPGRADED BLOCK ISLAND TO A WINTER STORM WARNING FOR THE
LATE AFTERNOON FORECAST PACKAGE. THERE MAY BE SOME MIXING WITH
RAIN IN THIS AREA AT TIMES.

EXPECT THIS TO BE A SNOW EVENT FOR THE VAST MAJORITY OF SOUTHERN
NEW ENGLAND. IT DOES BECOME A VERY CLOSE CALL NEAR THE SOUTH
COAST...BUT WERE LEANING TOWARDS IT STAYING MAINLY WET SNOW.
CONTINUED THE HIGH END WINTER WEATHER ADVISORY FOR THE CAPE
BECAUSE THEY MAY CHANGE TO RAIN FOR A TIME...ESPECIALLY EAST OF
HYANNIS. IF THE CHANGE OVER DOES NOT OCCUR...SNOWFALL TOTALS MAY
BE SOMEWHAT HIGHER. THE PRECIPITATION IS EXPECTED TO COME TO AN
END ACROSS THE MAJORITY OF THE AREA BY DAYBREAK MONDAY.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
MONDAY...
PRECIPITATION WILL HAVE LARGELY COME TO AN END FOR DAYBREAK MONDAY
WITH THE LOW PRESSURE RAPIDLY PULLING AWAY INTO THE CANADIAN
MARITIMES AND DRIER AIR/HIGH PRESSRUE MOVING IN FROM THE WEST.
INCREASING SUNSHINE EXPECTEED DURING THE DAY...WITH TEMPS TOPPING
OUT IN THE UPPER 20S TO MID 30S. HOWEVER AS WE GET TOWARDS
MIDDAY/AFTERNOON TIGHTENING GRADIENT WILL ALLOW NORTHWEST FLOW TO
BECOME BLUSTERY...WITH GUSTS OF 25 TO 30 MPH...25 TO 35 MPH ON THE
CAPE AND ISLANDS.

MONDAY NIGHT...
HIGH PRESSURE SETTLES OVER THE AREA WITH CLEAR SKIES EXPECTED.
GIVEN OUR SNOWPACK IN PLACE AND LIGHT WINDS...SHOULD BE ANOTHER
NIGHT FOR EXCELLENT RADIATIONAL COOLING. BECAUSE OF THIS DID
GENERALLY GO BELOW MODEL GUIDANCE FOR MIN TEMPS...LOOKING TO
ANTICIPATED SURFACE DEWPOINTS FOR A GUIDELINE ON HOW LOW WE CAN
GO. MAY SEE SOME SPOTS IN THE INTERIOR DROP BELOW ZERO.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...

BIG PICTURE... THE BROAD UPPER FLOW CONTINUES TO FEATURE A TROUGH
TRANSITING EAST ACROSS THE COUNTRY...REACHING THE EASTERN USA DURING
THE LATE WEEK AND LINGERING THROUGH THE WEEKEND. MEANWHILE AN UPPER
RIDGE SHIFTS FROM THE PACIFIC OCEAN BACK ASHORE ONTO THE WEST COAST.
CONTOUR HEIGHTS IN THE TROUGH ARE LOWEST THURSDAY-FRIDAY AND NEAR
NORMAL OVER THE WEEKEND. THIS MEANS A TREND TO COLDER TEMPS THURSDAY-
FRIDAY FOLLOWED BY A TREND CLOSER TO NORMAL OVER THE WEEKEND.

DAILIES...

TUESDAY... HIGH PRESSURE OVER THE REGION MOVES OFFSHORE BY AFTERNOON
WITH AIRFLOW SWINGING FROM NORTHWEST TO SOUTHWEST. THE SURFACE
AIRMASS STARTS OUT QUITE DRY WITH DEW POINTS IN THE SINGLE NUMBERS
BELOW ZERO TO START...CLIMBING TO 5-10 ABOVE BY EVENING. MODEL CROSS
SECTIONS SHOW INCREASING MOISTURE MORNING AND AFTERNOON ABOVE 700
MB. THIS SUGGESTS INCREASING MID AND HIGH CLOUDS WHILE DRY BENEATH.
LOW LEVEL JETS FROM THE CAROLINAS AND MIDWEST AND THE SURFACE
PRESSURE GRADIENT ALL SUGGEST THE INFLOW AND ISENTROPIC LIFT WILL
REMAIN TO OUR WEST THROUGH THE DAY...POSSIBLY ENTERING WESTERN MA/CT
AT OR AFTER 21Z. SO WE EXPECT INCREASING CLOUDS TUESDAY BUT
OTHERWISE DRY WEATHER THROUGH THE DAY. POSSIBLE LIGHT SNOW AROUND
THE EVENING RUSH HOUR IN THE CT RIVER VALLEY. TEMPS SHOULD REACH THE
MID 20S TO AROUND 30.

TUESDAY NIGHT-WEDNESDAY... NORTHERN AND SOUTHERN STREAM SHORTWAVES
MERGE OVER THE GREAT LAKES AND TRACK INTO CANADA. THIS BRINGS A MILD
FLOW OF AIR UP OVER NEW ENGLAND. THE LEADING EDGE OF THIS AIR
REACHES WESTERN SECTIONS TUESDAY EVENING AND EASTERN SECTIONS
TUESDAY NIGHT. TEMPERATURE PROFILES SUPPORT AN INITIAL PERIOD OF
SNOW CHANGING TO RAIN OR FREEZING RAIN OVERNIGHT. ACTUALLY...THE
MODELS MAY NOT BE HANDLING WELL THE CHILLING MASS OF SNOW AND COLD
GROUND /A.K.A. THE GIANT ICECUBE/ WHICH WOULD MEAN THE ACTUAL MAX
SFC TEMPS WILL BE COOLER THAN MODEL FORECASTS. TEMPERATURES AT 925
AND 950 MB WILL BE IN THE 30S...SO EXPECT SURFACE TEMPS NO HIGHER
THAN THE LOWER 40S.

THE SURFACE LOW PRESSURE AREA PASSES WELL NORTH OF NEW ENGLAND
WEDNESDAY AND SWINGS A COLD FRONT THROUGH THE REGION DURING THE
AFTERNOON OR EVENING. MOISTURE CROSS SECTIONS SHOW DECREASING RH IN
THE LIFT AND NUCLEATION ZONES ALOFT WEDNESDAY MORNING...SO THE TREND
THROUGH THE DAY SHOULD BE TO DIMINISHING POPS.

THURSDAY-FRIDAY... THE WEDNESDAY COLD FRONT WILL ALIGN WITH THE
UPPER FLOW AS IT MOVES SOUTH OF NEW ENGLAND...SLOWING ITS OFFSHORE
PROGRESS TO A CRAWL. MEANWHILE WE WILL BE UNDER THE RIGHT ENTRANCE
REGION OF THE SUPPORTING UPPER JET...A SOURCE OF UPPER VENTING. THIS
SHOULD SUPPORT LINGERING CLOUDS AND A CHANCE OF PCPN...WITH TEMPS
SUPPORTIVE OF SNOW. BEST CHANCE SOUTH COAST...LESSER CHANCE FARTHER
NORTH. THE JET AND SURFACE FRONT SWEEP OFFSHORE THURSDAY NIGHT. HIGH
PRESSURE THEN MOVES OVER THE EASTERN USA FOR FRIDAY. TEMPS ALOFT
SUPPORT MAX SFC TEMPS IN THE 20S.

SATURDAY-SUNDAY... ANOTHER NORTHERN STREAM SHORTWAVE AND COLD FRONT
SWINGS THROUGH THE FLOW SATURDAY. CROSS SECTIONS SHOW SOME MOISTURE
ALOFT BUT MOST OF IT IS CONCENTRATED TO OUR NORTH.  ALSO JUST
LIMITED LIFT TO WORK ON THAT MOISTURE. WE WILL HAVE 25-50 PCT SKY
COVER AND NIL POPS. HIGH PRESSURE THEN BUILDS FOR SUNDAY.

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...

TONIGHT...MODERATE CONFIDENCE. MVFR CIGS WITH PATCHES OF IFR
VALUES. VSBYS MOSTLY 1 TO 3 MILES WITH A ZONE FROM SOUTHERN CT
THROUGH RI AND SE MASS WHERE VSBYS ARE LIFR AT 1/2 MILE TO 1 MILE.
EXPECT THESE CONDITIONS TO LINGER THROUGH MIDNIGHT. THE ZONE OF
LOWER VSBYS AND SNOWFALL RATES COULD WOBBLE NORTH A FEW MILES AND
BRIEFLY APPROACH BOSTON BUT SHOULD PRIMARILY REMAIN TO THE SOUTH.

SOUTH FLOW BRINGS ENOUGH MILDER AIR NORTH TO MIX OR CHANGE THE
PCPN TO RAIN ON NANTUCKET AND PARTS OF THE OUTER CAPE. BULK OF THE
SNOW SHOULD ENDS 06Z WEST TO 10Z EAST /LATE TONIGHT AND EARLY
MONDAY/ MUCH OF THE REGION SHOULD IMPROVE TO VFR CONDITIONS BY
12-13Z MONDAY.

KBOS TAF...CONFIDENT IN OVERALL TRENDS BUT THERE IS UNCERTAINTY ON
TIMING. VSBYS BELOW 1 MILE SHOULD REMAIN TO THE SOUTH BUT COULD
BRIEFLY VISIT THE AIRPORT EARLY TONIGHT. THE BULK OF ACCUMULATING
SNOW IS EXPECTED BY MIDNIGHT.

KBDL TAF...CONFIDENT IN OVERALL TRENDS BUT THERE IS UNCERTAINTY ON
TIMING. BULK OF ACCUMULATING SNOW WITH IFR TO LIFR CONDITIONS
EXPECTED BY MIDNIGHT.

MONDAY AND MONDAY NIGHT...HIGH CONFIDENCE VFR. NORTHWEST WINDS
GUSTING TO 25 TO 30 MPH ACROSS MUCH OF THE AREA DURING MONDAY
AFTERNOON...25 TO 35 MPH GUSTS CAPE/ISLANDS. WINDS DIMINISHING
TOWARDS SUNSET.

OUTLOOK...TUESDAY THROUGH FRIDAY...

TUESDAY...MODERATE CONFIDENCE. VFR DURING THE DAY WITH INCREASING
SKY COVER. MVFR CIGS/VSBYS POSSIBLE LATE IN THE DAY CT RIVER VALLEY.

TUESDAY NIGHT-WEDNESDAY...MODERATE CONFIDENCE. CONDITIONS LOWERING
TO IFR/LIFR. INITIALLY SNOW BUT CHANGING TO SLEET/FREEZING RAIN
DURING THE NIGHT AND RAIN IN THE COASTAL PLAIN OVERNIGHT. PCPN
CHANGES TO RAIN ALL AREAS WEDNESDAY...BUT COLD SURFACES COULD
MAINTAIN A FREEZING RAIN ELEMENT WEDNESDAY MORNING. COLDER AIR MOVES
IN WEDNESDAY NIGHT CHANGING ANY RAIN TO SNOW.

THURSDAY...LOW CONFIDENCE. VFR NORTH OF A HFD-BOS LINE. MVFR CIGS
AND AREAS OF MVFR/IFR VSBYS IN SNOW...DIMINISHING BY EVENING.
NORTHWEST WINDS GUSTING TO 20 KNOTS.

FRIDAY...MODERATE CONFIDENCE. VFR.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...HIGH CONFIDENCE.

A WEAK WAVE OF LOW PRESSURE MOVES ACROSS THE WATERS TONIGHT.
THIS SYSTEM REALLY INTENSIFIES AS IT MOVES INTO THE CANADIAN
MARITIMES NEAR DAYBREAK MONDAY...SO WESTERLY WIND GUSTS MAY REACH
20 TO 25 KNOTS NEAR 12Z MONDAY. OTHERWISE...RAIN AND SNOW THIS
EVENING AND TONIGHT WILL REDUCE VISIBILITIES AT TIMES FOR
MARINERS.

MONDAY...AS THE LOW PRESSURE GOING INTO THE CANADIAN MARITIMES
INTENSFIES...INCREASING NORTHWEST WINDS ARE EXPECTED OVER THE
SOUTHERN NEW ENGLAND COASTAL WATERS...WITH GALE FORCE GUSTS
EXPECTED. GALE WARNINGS HAVE BEEN HOISTED FOR ALL COASTAL WATERS
FROM MIDDAY MONDAY INTO MONDAY NIGHT.

OUTLOOK...TUESDAY THROUGH FRIDAY..MODERATE CONFIDENCE.

TUESDAY... LINGERING 5 FOOT SEAS SOUTH AND EAST OF NANTUCKET IN THE
MORNING BUT DIMINISHING. NORTHWEST WINDS DIMINISHING FROM 20 KNOTS.
ANY SMALL CRAFT ADVISORY SHOULD END IN THE MORNING.

TUESDAY NIGHT-WEDNESDAY...SOUTH TO SOUTHWEST WINDS WILL INCREASE TO
20-25 KNOTS. SEAS WILL BUILD 6 TO 10 FEET ON THE OUTER WATERS AND ON
RI SOUND. REDUCED VSBYS...INITIALLY SNOW BUT CHANGING TO RAIN. A
SMALL CRAFT ADVISORY MAY BE NEEDED.

THURSDAY...NORTHWEST WIND GUSTING TO 25 KNOTS. SEAS 5 TO 8 FEET
MAINLY ON THE OUTER WATERS...DIMINISHING LATE. A SMALL CRAFT
ADVISORY MAY BE NEEDED.

FRIDAY... SHIFTING WINDS LESS THAN 20 KNOTS. SEAS LESS THAN 5 FEET.
QUIET WEATHER.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR CTZ002>004.
MA...WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR MAZ017>021.
     WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR MAZ002>016-
     022>024-026.
RI...WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR RIZ002>008.
     WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR RIZ001.
MARINE...GALE WARNING FROM 11 AM MONDAY TO 4 AM EST TUESDAY FOR ANZ231-
     232-250-251-254-255.
     GALE WARNING FROM 11 AM TO 11 PM EST MONDAY FOR ANZ233>235-237-
     256.
     GALE WARNING FROM 11 AM TO 8 PM EST MONDAY FOR ANZ230-236.

&&

$$
SYNOPSIS...WTB/NMB
NEAR TERM...WTB/NMB
SHORT TERM...NMB
LONG TERM...WTB
AVIATION...WTB/NMB
MARINE...WTB/NMB



000
FXUS61 KBOX 012157
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
457 PM EST SUN MAR 1 2015

.SYNOPSIS...
A FAST MOVING LOW PRESSURE SYSTEM WILL BRING ACCUMULATING SNOW
THIS EVENING AND TONIGHT WITH THE HIGHEST AMOUNTS EXPECTED SOUTH
OF THE MASSACHUSETTS TURNPIKE. HIGH PRESSURE BRINGS DRY COLD AIR
FOR THE EARLY WEEK. LOW PRESSURE FROM NORTHERN CANADA AND
ASSOCIATED LOW FORMING OVER THE PLAINS MONDAY WILL MERGE...THEN
PASS WEST AND NORTH OF NEW ENGLAND. THIS WILL SWING A COLD FRONT
ACROSS THE REGION ON WEDNESDAY. DRY AND COLD WEATHER RETURNS FOR
THE END OF THE WEEK. ANOTHER COLD FRONT MOVES THROUGH ON SATURDAY.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
445 PM UPDATE...

LOW PRESSURE EMERGING FROM THE MID ATLANTIC COASTLINE IS EXPECTED
TO PASS SOUTHEAST OF NANTUCKET TONIGHT...BRINGING A WIDESPREAD
SNOW TO SOUTHERN NEW ENGLAND. SURFACE OBS AS OF 21Z INDICATE THAT
SNOW HAS OVERSPREAD THE ENTIRE AREA. THE STRONGEST RADAR
RETURNS AT 21Z WERE NEAR THE SOUTH COAST OF CT INTO RI...AND TO
THE SOUTHWEST. THE BETTER FORCING FROM THIS EVENT IS EXPECTED TO OCCUR
TO THE SOUTH OF THE MA TURNPIKE. 12Z MODELS WERE IN DECENT
AGREEMENT ON PLACING THE HIGHEST QPF IN THAT AREA.

BECAUSE OF THE QUICK HITTING NATURE OF THIS SYSTEM WITH A SHORT
LIVED WINDOW FOR VERY STRONG LIFT/FORCING...CONTINUE TO THINK THAT
FOR MOST OF THE REGION WINTER WEATHER ADVISORY/S FOR 3 TO 6 INCHES
OF SNOW WILL COVER THIS EVENT. HOWEVER...GIVEN THERE IS NICE
OMEGA IN THE SNOW GROWTH REGION...WE MIGHT BE LOOKING AT SOME
DECENT RATIOS. SO WE STILL CAN NOT RULE OUT THE LOW RISK OF
REACHING WARNING AMOUNTS...ESPECIALLY ACROSS NORTHERN CT AND
NORTHWEST RI.

WE DID UPGRADED BLOCK ISLAND TO A WINTER STORM WARNING FOR THE
LATE AFTERNOON FORECAST PACKAGE. THERE MAY BE SOME MIXING WITH
RAIN IN THIS AREA AT TIMES.

EXPECT THIS TO BE A SNOW EVENT FOR THE VAST MAJORITY OF SOUTHERN
NEW ENGLAND. IT DOES BECOME A VERY CLOSE CALL NEAR THE SOUTH
COAST...BUT WERE LEANING TOWARDS IT STAYING MAINLY WET SNOW.
CONTINUED THE HIGH END WINTER WEATHER ADVISORY FOR THE CAPE
BECAUSE THEY MAY CHANGE TO RAIN FOR A TIME...ESPECIALLY EAST OF
HYANNIS. IF THE CHANGE OVER DOES NOT OCCUR...SNOWFALL TOTALS MAY
BE SOMEWHAT HIGHER. THE PRECIPITATION IS EXPECTED TO COME TO AN
END ACROSS THE MAJORITY OF THE AREA BY DAYBREAK MONDAY.

&&

.SHORT TERM /MONDAY AND MONDAY NIGHT/...

MONDAY...
PRECIPITATION WILL HAVE LARGELY COME TO AN END FOR DAYBREAK MONDAY
...WITH THE LOW PRESSURE RAPIDLY PULLING AWAY INTO THE CANADIAN
MARITIMES AND DRIER AIR/HIGH PRESSRUE MOVING IN FROM THE WEST.
INCREASING SUNSHINE EXPECTEED DURING THE DAY...WITH TEMPS TOPPING
OUT IN THE UPPER 20S TO MID 30S. HOWEVER AS WE GET TOWARDS
MIDDAY/AFTERNOON TIGHTENING GRADIENT WILL ALLOW NORTHWEST FLOW TO
BECOME BLUSTERY...WITH GUSTS OF 25 TO 30 MPH...25 TO 35 MPH ON THE
CAPE AND ISLANDS.

MONDAY NIGHT...
HIGH PRESSURE SETTLES OVER THE AREA WITH CLEAR SKIES EXPECTED.
GIVEN OUR SNOWPACK IN PLACE AND LIGHT WINDS...SHOULD BE ANOTHER
NIGHT FOR EXCELLENT RADIATIONAL COOLING. BECAUSE OF THIS DID
GENERALLY GO BELOW MODEL GUIDANCE FOR MIN TEMPS...LOOKING TO
ANTICIPATED SURFACE DEWPOINTS FOR A GUIDELINE ON HOW LOW WE CAN
GO. MAY SEE SOME SPOTS IN THE INTERIOR DROP BELOW ZERO.

.LONG TERM /TUESDAY THROUGH SUNDAY/...
BIG PICTURE... THE BROAD UPPER FLOW CONTINUES TO FEATURE A TROUGH
TRANSITING EAST ACROSS THE COUNTRY...REACHING THE EASTERN USA DURING
THE LATE WEEK AND LINGERING THROUGH THE WEEKEND. MEANWHILE AN UPPER
RIDGE SHIFTS FROM THE PACIFIC OCEAN BACK ASHORE ONTO THE WEST COAST.
CONTOUR HEIGHTS IN THE TROUGH ARE LOWEST THURSDAY-FRIDAY AND NEAR
NORMAL OVER THE WEEKEND. THIS MEANS A TREND TO COLDER TEMPS THURSDAY-
FRIDAY FOLLOWED BY A TREND CLOSER TO NORMAL OVER THE WEEKEND.

DAILIES...

TUESDAY... HIGH PRESSURE OVER THE REGION MOVES OFFSHORE BY AFTERNOON
WITH AIRFLOW SWINGING FROM NORTHWEST TO SOUTHWEST. THE SURFACE
AIRMASS STARTS OUT QUITE DRY WITH DEW POINTS IN THE SINGLE NUMBERS
BELOW ZERO TO START...CLIMBING TO 5-10 ABOVE BY EVENING. MODEL CROSS
SECTIONS SHOW INCREASING MOISTURE MORNING AND AFTERNOON ABOVE 700
MB. THIS SUGGESTS INCREASING MID AND HIGH CLOUDS WHILE DRY BENEATH.
LOW LEVEL JETS FROM THE CAROLINAS AND MIDWEST AND THE SURFACE
PRESSURE GRADIENT ALL SUGGEST THE INFLOW AND ISENTROPIC LIFT WILL
REMAIN TO OUR WEST THROUGH THE DAY...POSSIBLY ENTERING WESTERN MA/CT
AT OR AFTER 21Z. SO WE EXPECT INCREASING CLOUDS TUESDAY BUT
OTHERWISE DRY WEATHER THROUGH THE DAY. POSSIBLE LIGHT SNOW AROUND
THE EVENING RUSH HOUR IN THE CT RIVER VALLEY. TEMPS SHOULD REACH THE
MID 20S TO AROUND 30.

TUESDAY NIGHT-WEDNESDAY... NORTHERN AND SOUTHERN STREAM SHORTWAVES
MERGE OVER THE GREAT LAKES AND TRACK INTO CANADA. THIS BRINGS A MILD
FLOW OF AIR UP OVER NEW ENGLAND. THE LEADING EDGE OF THIS AIR
REACHES WESTERN SECTIONS TUESDAY EVENING AND EASTERN SECTIONS
TUESDAY NIGHT. TEMPERATURE PROFILES SUPPORT AN INITIAL PERIOD OF
SNOW CHANGING TO RAIN OR FREEZING RAIN OVERNIGHT. ACTUALLY...THE
MODELS MAY NOT BE HANDLING WELL THE CHILLING MASS OF SNOW AND COLD
GROUND /A.K.A. THE GIANT ICECUBE/ WHICH WOULD MEAN THE ACTUAL MAX
SFC TEMPS WILL BE COOLER THAN MODEL FORECASTS. TEMPERATURES AT 925
AND 950 MB WILL BE IN THE 30S...SO EXPECT SURFACE TEMPS NO HIGHER
THAN THE LOWER 40S.

THE SURFACE LOW PRESSURE AREA PASSES WELL NORTH OF NEW ENGLAND
WEDNESDAY AND SWINGS A COLD FRONT THROUGH THE REGION DURING THE
AFTERNOON OR EVENING. MOISTURE CROSS SECTIONS SHOW DECREASING RH IN
THE LIFT AND NUCLEATION ZONES ALOFT WEDNESDAY MORNING...SO THE TREND
THROUGH THE DAY SHOULD BE TO DIMINISHING POPS.

THURSDAY-FRIDAY... THE WEDNESDAY COLD FRONT WILL ALIGN WITH THE
UPPER FLOW AS IT MOVES SOUTH OF NEW ENGLAND...SLOWING ITS OFFSHORE
PROGRESS TO A CRAWL. MEANWHILE WE WILL BE UNDER THE RIGHT ENTRANCE
REGION OF THE SUPPORTING UPPER JET...A SOURCE OF UPPER VENTING. THIS
SHOULD SUPPORT LINGERING CLOUDS AND A CHANCE OF PCPN...WITH TEMPS
SUPPORTIVE OF SNOW. BEST CHANCE SOUTH COAST...LESSER CHANCE FARTHER
NORTH. THE JET AND SURFACE FRONT SWEEP OFFSHORE THURSDAY NIGHT. HIGH
PRESSURE THEN MOVES OVER THE EASTERN USA FOR FRIDAY. TEMPS ALOFT
SUPPORT MAX SFC TEMPS IN THE 20S.

SATURDAY-SUNDAY... ANOTHER NORTHERN STREAM SHORTWAVE AND COLD FRONT
SWINGS THROUGH THE FLOW SATURDAY. CROSS SECTIONS SHOW SOME MOISTURE
ALOFT BUT MOST OF IT IS CONCENTRATED TO OUR NORTH.  ALSO JUST
LIMITED LIFT TO WORK ON THAT MOISTURE. WE WILL HAVE 25-50 PCT SKY
COVER AND NIL POPS. HIGH PRESSURE THEN BUILDS FOR SUNDAY.

&&

.AVIATION /22Z SUNDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TODAY AND TONIGHT/...

2130Z UPDATE...

TONIGHT...MODERATE CONFIDENCE. MVFR CIGS DETERIORATING TO
IFR/LIFR IN SNOW. THE BULK OF THE MODERATE TO EVEN BRIEFLY HEAVY
SNOW WILL OCCUR THIS EVENING. THE LOWEST CONDITIONS WILL MOST
LIKELY BE SOUTH OF THE MA TURNPIKE. PTYPE PRETTY MUCH ALL
SNOW...EXCEPT FOR THE VERY IMMEDIATE SOUTH COAST/CAPE WHERE SNOW
MAY MIX WITH OR CHANGE TO RAIN FOR A TIME. WHETHER OR NOT THAT
HAPPENS IS UNCERTAIN...BUT WE DO THINK THAT AT LEAST THE ISLANDS
WILL MIX OR CHANGE TO RAIN.

BULK OF SNOW ENDS BY 8Z TO 9Z TONIGHT AND MUCH OF THE THE REGION
SHOULD IMPROVE TO VFR CONDITIONS BY 12-13Z MONDAY.

KBOS TAF...CONFIDENT IN OVERALL TRENDS BUT THERE IS UNCERTAINTY ON
TIMING. THE BULK OF ACCUMULATING SNOW WITH IFR TO LIFR CONDITIONS
EXPECTED MAINLY THIS EVENING.

KBDL TAF...CONFIDENT IN OVERALL TRENDS BUT THERE IS UNCERTAINTY ON
TIMING. BULK OF ACCUMULATING SNOW WITH IFR TO LIFR CONDITIONS
EXPECTED MAINLY THIS EVENING.

MONDAY AND MONDAY NIGHT...HIGH CONFIDENCE VFR. NORTHWEST WINDS
GUSTING TO 25 TO 30 MPH ACROSS MUCH OF THE AREA DURING MONDAY
AFTERNOON...25 TO 35 MPH GUSTS CAPE/ISLANDS. WINDS DIMINISHING
TOWARDS SUNSET.

OUTLOOK...TUESDAY THROUGH FRIDAY...

TUESDAY...MODERATE CONFIDENCE. VFR DURING THE DAY WITH INCREASING
SKY COVER. MVFR CIGS/VSBYS POSSIBLE LATE IN THE DAY CT RIVER VALLEY.

TUESDAY NIGHT-WEDNESDAY...MODERATE CONFIDENCE. CONDITIONS LOWERING
TO IFR/LIFR. INITIALLY SNOW BUT CHANGING TO SLEET/FREEZING RAIN
DURING THE NIGHT AND RAIN IN THE COASTAL PLAIN OVERNIGHT. PCPN
CHANGES TO RAIN ALL AREAS WEDNESDAY...BUT COLD SURFACES COULD
MAINTAIN A FREEZING RAIN ELEMENT WEDNESDAY MORNING. COLDER AIR MOVES
IN WEDNESDAY NIGHT CHANGING ANY RAIN TO SNOW.

THURSDAY...LOW CONFIDENCE. VFR NORTH OF A HFD-BOS LINE. MVFR CIGS
AND AREAS OF MVFR/IFR VSBYS IN SNOW...DIMINISHING BY EVENING.
NORTHWEST WINDS GUSTING TO 20 KNOTS.

FRIDAY...MODERATE CONFIDENCE. VFR.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...HIGH CONFIDENCE.

A WEAK WAVE OF LOW PRESSURE MOVES ACROSS THE WATERS TONIGHT.
THIS SYSTEM REALLY INTENSIFIES AS IT MOVES INTO THE CANADIAN
MARITIMES NEAR DAYBREAK MONDAY...SO WESTERLY WIND GUSTS MAY REACH
20 TO 25 KNOTS NEAR 12Z MONDAY. OTHERWISE...RAIN AND SNOW THIS
EVENING AND TONIGHT WILL REDUCE VISIBILITIES AT TIMES FOR
MARINERS.

MONDAY...AS THE LOW PRESSURE GOING INTO THE CANADIAN MARITIMES
INTENSFIES...INCREASING NORTHWEST WINDS ARE EXPECTED OVER THE
SOUTHERN NEW ENGLAND COASTAL WATERS...WITH GALE FORCE GUSTS
EXPECTED. GALE WARNINGS HAVE BEEN HOISTED FOR ALL COASTAL WATERS
FROM MIDDAY MONDAY INTO MONDAY NIGHT.

OUTLOOK...TUESDAY THROUGH FRIDAY..MODERATE CONFIDENCE.

TUESDAY... LINGERING 5 FOOT SEAS SOUTH AND EAST OF NANTUCKET IN THE
MORNING BUT DIMINISHING. NORTHWEST WINDS DIMINISHING FROM 20 KNOTS.
ANY SMALL CRAFT ADVISORY SHOULD END IN THE MORNING.

TUESDAY NIGHT-WEDNESDAY...SOUTH TO SOUTHWEST WINDS WILL INCREASE TO
20-25 KNOTS. SEAS WILL BUILD 6 TO 10 FEET ON THE OUTER WATERS AND ON
RI SOUND. REDUCED VSBYS...INITIALLY SNOW BUT CHANGING TO RAIN. A
SMALL CRAFT ADVISORY MAY BE NEEDED.

THURSDAY...NORTHWEST WIND GUSTING TO 25 KNOTS. SEAS 5 TO 8 FEET
MAINLY ON THE OUTER WATERS...DIMINISHING LATE. A SMALL CRAFT
ADVISORY MAY BE NEEDED.

FRIDAY... SHIFTING WINDS LESS THAN 20 KNOTS. SEAS LESS THAN 5 FEET.
QUIET WEATHER.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR CTZ002>004.
MA...WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR MAZ017>021.
     WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR MAZ002>016-
     022>024-026.
RI...WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR RIZ002>008.
     WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR RIZ001.
MARINE...GALE WARNING FROM 11 AM MONDAY TO 4 AM EST TUESDAY FOR ANZ231-
     232-250-251-254-255.
     GALE WARNING FROM 11 AM TO 11 PM EST MONDAY FOR ANZ233>235-237-
     256.
     GALE WARNING FROM 11 AM TO 8 PM EST MONDAY FOR ANZ230-236.

&&

$$
SYNOPSIS...WTB/NMB
NEAR TERM...FRANK/DOODY/NMB
SHORT TERM...NMB
LONG TERM...WTB
AVIATION...WTB/NMB
MARINE...WTB/NMB




000
FXUS61 KBOX 012157
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
457 PM EST SUN MAR 1 2015

.SYNOPSIS...
A FAST MOVING LOW PRESSURE SYSTEM WILL BRING ACCUMULATING SNOW
THIS EVENING AND TONIGHT WITH THE HIGHEST AMOUNTS EXPECTED SOUTH
OF THE MASSACHUSETTS TURNPIKE. HIGH PRESSURE BRINGS DRY COLD AIR
FOR THE EARLY WEEK. LOW PRESSURE FROM NORTHERN CANADA AND
ASSOCIATED LOW FORMING OVER THE PLAINS MONDAY WILL MERGE...THEN
PASS WEST AND NORTH OF NEW ENGLAND. THIS WILL SWING A COLD FRONT
ACROSS THE REGION ON WEDNESDAY. DRY AND COLD WEATHER RETURNS FOR
THE END OF THE WEEK. ANOTHER COLD FRONT MOVES THROUGH ON SATURDAY.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
445 PM UPDATE...

LOW PRESSURE EMERGING FROM THE MID ATLANTIC COASTLINE IS EXPECTED
TO PASS SOUTHEAST OF NANTUCKET TONIGHT...BRINGING A WIDESPREAD
SNOW TO SOUTHERN NEW ENGLAND. SURFACE OBS AS OF 21Z INDICATE THAT
SNOW HAS OVERSPREAD THE ENTIRE AREA. THE STRONGEST RADAR
RETURNS AT 21Z WERE NEAR THE SOUTH COAST OF CT INTO RI...AND TO
THE SOUTHWEST. THE BETTER FORCING FROM THIS EVENT IS EXPECTED TO OCCUR
TO THE SOUTH OF THE MA TURNPIKE. 12Z MODELS WERE IN DECENT
AGREEMENT ON PLACING THE HIGHEST QPF IN THAT AREA.

BECAUSE OF THE QUICK HITTING NATURE OF THIS SYSTEM WITH A SHORT
LIVED WINDOW FOR VERY STRONG LIFT/FORCING...CONTINUE TO THINK THAT
FOR MOST OF THE REGION WINTER WEATHER ADVISORY/S FOR 3 TO 6 INCHES
OF SNOW WILL COVER THIS EVENT. HOWEVER...GIVEN THERE IS NICE
OMEGA IN THE SNOW GROWTH REGION...WE MIGHT BE LOOKING AT SOME
DECENT RATIOS. SO WE STILL CAN NOT RULE OUT THE LOW RISK OF
REACHING WARNING AMOUNTS...ESPECIALLY ACROSS NORTHERN CT AND
NORTHWEST RI.

WE DID UPGRADED BLOCK ISLAND TO A WINTER STORM WARNING FOR THE
LATE AFTERNOON FORECAST PACKAGE. THERE MAY BE SOME MIXING WITH
RAIN IN THIS AREA AT TIMES.

EXPECT THIS TO BE A SNOW EVENT FOR THE VAST MAJORITY OF SOUTHERN
NEW ENGLAND. IT DOES BECOME A VERY CLOSE CALL NEAR THE SOUTH
COAST...BUT WERE LEANING TOWARDS IT STAYING MAINLY WET SNOW.
CONTINUED THE HIGH END WINTER WEATHER ADVISORY FOR THE CAPE
BECAUSE THEY MAY CHANGE TO RAIN FOR A TIME...ESPECIALLY EAST OF
HYANNIS. IF THE CHANGE OVER DOES NOT OCCUR...SNOWFALL TOTALS MAY
BE SOMEWHAT HIGHER. THE PRECIPITATION IS EXPECTED TO COME TO AN
END ACROSS THE MAJORITY OF THE AREA BY DAYBREAK MONDAY.

&&

.SHORT TERM /MONDAY AND MONDAY NIGHT/...

MONDAY...
PRECIPITATION WILL HAVE LARGELY COME TO AN END FOR DAYBREAK MONDAY
...WITH THE LOW PRESSURE RAPIDLY PULLING AWAY INTO THE CANADIAN
MARITIMES AND DRIER AIR/HIGH PRESSRUE MOVING IN FROM THE WEST.
INCREASING SUNSHINE EXPECTEED DURING THE DAY...WITH TEMPS TOPPING
OUT IN THE UPPER 20S TO MID 30S. HOWEVER AS WE GET TOWARDS
MIDDAY/AFTERNOON TIGHTENING GRADIENT WILL ALLOW NORTHWEST FLOW TO
BECOME BLUSTERY...WITH GUSTS OF 25 TO 30 MPH...25 TO 35 MPH ON THE
CAPE AND ISLANDS.

MONDAY NIGHT...
HIGH PRESSURE SETTLES OVER THE AREA WITH CLEAR SKIES EXPECTED.
GIVEN OUR SNOWPACK IN PLACE AND LIGHT WINDS...SHOULD BE ANOTHER
NIGHT FOR EXCELLENT RADIATIONAL COOLING. BECAUSE OF THIS DID
GENERALLY GO BELOW MODEL GUIDANCE FOR MIN TEMPS...LOOKING TO
ANTICIPATED SURFACE DEWPOINTS FOR A GUIDELINE ON HOW LOW WE CAN
GO. MAY SEE SOME SPOTS IN THE INTERIOR DROP BELOW ZERO.

.LONG TERM /TUESDAY THROUGH SUNDAY/...
BIG PICTURE... THE BROAD UPPER FLOW CONTINUES TO FEATURE A TROUGH
TRANSITING EAST ACROSS THE COUNTRY...REACHING THE EASTERN USA DURING
THE LATE WEEK AND LINGERING THROUGH THE WEEKEND. MEANWHILE AN UPPER
RIDGE SHIFTS FROM THE PACIFIC OCEAN BACK ASHORE ONTO THE WEST COAST.
CONTOUR HEIGHTS IN THE TROUGH ARE LOWEST THURSDAY-FRIDAY AND NEAR
NORMAL OVER THE WEEKEND. THIS MEANS A TREND TO COLDER TEMPS THURSDAY-
FRIDAY FOLLOWED BY A TREND CLOSER TO NORMAL OVER THE WEEKEND.

DAILIES...

TUESDAY... HIGH PRESSURE OVER THE REGION MOVES OFFSHORE BY AFTERNOON
WITH AIRFLOW SWINGING FROM NORTHWEST TO SOUTHWEST. THE SURFACE
AIRMASS STARTS OUT QUITE DRY WITH DEW POINTS IN THE SINGLE NUMBERS
BELOW ZERO TO START...CLIMBING TO 5-10 ABOVE BY EVENING. MODEL CROSS
SECTIONS SHOW INCREASING MOISTURE MORNING AND AFTERNOON ABOVE 700
MB. THIS SUGGESTS INCREASING MID AND HIGH CLOUDS WHILE DRY BENEATH.
LOW LEVEL JETS FROM THE CAROLINAS AND MIDWEST AND THE SURFACE
PRESSURE GRADIENT ALL SUGGEST THE INFLOW AND ISENTROPIC LIFT WILL
REMAIN TO OUR WEST THROUGH THE DAY...POSSIBLY ENTERING WESTERN MA/CT
AT OR AFTER 21Z. SO WE EXPECT INCREASING CLOUDS TUESDAY BUT
OTHERWISE DRY WEATHER THROUGH THE DAY. POSSIBLE LIGHT SNOW AROUND
THE EVENING RUSH HOUR IN THE CT RIVER VALLEY. TEMPS SHOULD REACH THE
MID 20S TO AROUND 30.

TUESDAY NIGHT-WEDNESDAY... NORTHERN AND SOUTHERN STREAM SHORTWAVES
MERGE OVER THE GREAT LAKES AND TRACK INTO CANADA. THIS BRINGS A MILD
FLOW OF AIR UP OVER NEW ENGLAND. THE LEADING EDGE OF THIS AIR
REACHES WESTERN SECTIONS TUESDAY EVENING AND EASTERN SECTIONS
TUESDAY NIGHT. TEMPERATURE PROFILES SUPPORT AN INITIAL PERIOD OF
SNOW CHANGING TO RAIN OR FREEZING RAIN OVERNIGHT. ACTUALLY...THE
MODELS MAY NOT BE HANDLING WELL THE CHILLING MASS OF SNOW AND COLD
GROUND /A.K.A. THE GIANT ICECUBE/ WHICH WOULD MEAN THE ACTUAL MAX
SFC TEMPS WILL BE COOLER THAN MODEL FORECASTS. TEMPERATURES AT 925
AND 950 MB WILL BE IN THE 30S...SO EXPECT SURFACE TEMPS NO HIGHER
THAN THE LOWER 40S.

THE SURFACE LOW PRESSURE AREA PASSES WELL NORTH OF NEW ENGLAND
WEDNESDAY AND SWINGS A COLD FRONT THROUGH THE REGION DURING THE
AFTERNOON OR EVENING. MOISTURE CROSS SECTIONS SHOW DECREASING RH IN
THE LIFT AND NUCLEATION ZONES ALOFT WEDNESDAY MORNING...SO THE TREND
THROUGH THE DAY SHOULD BE TO DIMINISHING POPS.

THURSDAY-FRIDAY... THE WEDNESDAY COLD FRONT WILL ALIGN WITH THE
UPPER FLOW AS IT MOVES SOUTH OF NEW ENGLAND...SLOWING ITS OFFSHORE
PROGRESS TO A CRAWL. MEANWHILE WE WILL BE UNDER THE RIGHT ENTRANCE
REGION OF THE SUPPORTING UPPER JET...A SOURCE OF UPPER VENTING. THIS
SHOULD SUPPORT LINGERING CLOUDS AND A CHANCE OF PCPN...WITH TEMPS
SUPPORTIVE OF SNOW. BEST CHANCE SOUTH COAST...LESSER CHANCE FARTHER
NORTH. THE JET AND SURFACE FRONT SWEEP OFFSHORE THURSDAY NIGHT. HIGH
PRESSURE THEN MOVES OVER THE EASTERN USA FOR FRIDAY. TEMPS ALOFT
SUPPORT MAX SFC TEMPS IN THE 20S.

SATURDAY-SUNDAY... ANOTHER NORTHERN STREAM SHORTWAVE AND COLD FRONT
SWINGS THROUGH THE FLOW SATURDAY. CROSS SECTIONS SHOW SOME MOISTURE
ALOFT BUT MOST OF IT IS CONCENTRATED TO OUR NORTH.  ALSO JUST
LIMITED LIFT TO WORK ON THAT MOISTURE. WE WILL HAVE 25-50 PCT SKY
COVER AND NIL POPS. HIGH PRESSURE THEN BUILDS FOR SUNDAY.

&&

.AVIATION /22Z SUNDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TODAY AND TONIGHT/...

2130Z UPDATE...

TONIGHT...MODERATE CONFIDENCE. MVFR CIGS DETERIORATING TO
IFR/LIFR IN SNOW. THE BULK OF THE MODERATE TO EVEN BRIEFLY HEAVY
SNOW WILL OCCUR THIS EVENING. THE LOWEST CONDITIONS WILL MOST
LIKELY BE SOUTH OF THE MA TURNPIKE. PTYPE PRETTY MUCH ALL
SNOW...EXCEPT FOR THE VERY IMMEDIATE SOUTH COAST/CAPE WHERE SNOW
MAY MIX WITH OR CHANGE TO RAIN FOR A TIME. WHETHER OR NOT THAT
HAPPENS IS UNCERTAIN...BUT WE DO THINK THAT AT LEAST THE ISLANDS
WILL MIX OR CHANGE TO RAIN.

BULK OF SNOW ENDS BY 8Z TO 9Z TONIGHT AND MUCH OF THE THE REGION
SHOULD IMPROVE TO VFR CONDITIONS BY 12-13Z MONDAY.

KBOS TAF...CONFIDENT IN OVERALL TRENDS BUT THERE IS UNCERTAINTY ON
TIMING. THE BULK OF ACCUMULATING SNOW WITH IFR TO LIFR CONDITIONS
EXPECTED MAINLY THIS EVENING.

KBDL TAF...CONFIDENT IN OVERALL TRENDS BUT THERE IS UNCERTAINTY ON
TIMING. BULK OF ACCUMULATING SNOW WITH IFR TO LIFR CONDITIONS
EXPECTED MAINLY THIS EVENING.

MONDAY AND MONDAY NIGHT...HIGH CONFIDENCE VFR. NORTHWEST WINDS
GUSTING TO 25 TO 30 MPH ACROSS MUCH OF THE AREA DURING MONDAY
AFTERNOON...25 TO 35 MPH GUSTS CAPE/ISLANDS. WINDS DIMINISHING
TOWARDS SUNSET.

OUTLOOK...TUESDAY THROUGH FRIDAY...

TUESDAY...MODERATE CONFIDENCE. VFR DURING THE DAY WITH INCREASING
SKY COVER. MVFR CIGS/VSBYS POSSIBLE LATE IN THE DAY CT RIVER VALLEY.

TUESDAY NIGHT-WEDNESDAY...MODERATE CONFIDENCE. CONDITIONS LOWERING
TO IFR/LIFR. INITIALLY SNOW BUT CHANGING TO SLEET/FREEZING RAIN
DURING THE NIGHT AND RAIN IN THE COASTAL PLAIN OVERNIGHT. PCPN
CHANGES TO RAIN ALL AREAS WEDNESDAY...BUT COLD SURFACES COULD
MAINTAIN A FREEZING RAIN ELEMENT WEDNESDAY MORNING. COLDER AIR MOVES
IN WEDNESDAY NIGHT CHANGING ANY RAIN TO SNOW.

THURSDAY...LOW CONFIDENCE. VFR NORTH OF A HFD-BOS LINE. MVFR CIGS
AND AREAS OF MVFR/IFR VSBYS IN SNOW...DIMINISHING BY EVENING.
NORTHWEST WINDS GUSTING TO 20 KNOTS.

FRIDAY...MODERATE CONFIDENCE. VFR.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...HIGH CONFIDENCE.

A WEAK WAVE OF LOW PRESSURE MOVES ACROSS THE WATERS TONIGHT.
THIS SYSTEM REALLY INTENSIFIES AS IT MOVES INTO THE CANADIAN
MARITIMES NEAR DAYBREAK MONDAY...SO WESTERLY WIND GUSTS MAY REACH
20 TO 25 KNOTS NEAR 12Z MONDAY. OTHERWISE...RAIN AND SNOW THIS
EVENING AND TONIGHT WILL REDUCE VISIBILITIES AT TIMES FOR
MARINERS.

MONDAY...AS THE LOW PRESSURE GOING INTO THE CANADIAN MARITIMES
INTENSFIES...INCREASING NORTHWEST WINDS ARE EXPECTED OVER THE
SOUTHERN NEW ENGLAND COASTAL WATERS...WITH GALE FORCE GUSTS
EXPECTED. GALE WARNINGS HAVE BEEN HOISTED FOR ALL COASTAL WATERS
FROM MIDDAY MONDAY INTO MONDAY NIGHT.

OUTLOOK...TUESDAY THROUGH FRIDAY..MODERATE CONFIDENCE.

TUESDAY... LINGERING 5 FOOT SEAS SOUTH AND EAST OF NANTUCKET IN THE
MORNING BUT DIMINISHING. NORTHWEST WINDS DIMINISHING FROM 20 KNOTS.
ANY SMALL CRAFT ADVISORY SHOULD END IN THE MORNING.

TUESDAY NIGHT-WEDNESDAY...SOUTH TO SOUTHWEST WINDS WILL INCREASE TO
20-25 KNOTS. SEAS WILL BUILD 6 TO 10 FEET ON THE OUTER WATERS AND ON
RI SOUND. REDUCED VSBYS...INITIALLY SNOW BUT CHANGING TO RAIN. A
SMALL CRAFT ADVISORY MAY BE NEEDED.

THURSDAY...NORTHWEST WIND GUSTING TO 25 KNOTS. SEAS 5 TO 8 FEET
MAINLY ON THE OUTER WATERS...DIMINISHING LATE. A SMALL CRAFT
ADVISORY MAY BE NEEDED.

FRIDAY... SHIFTING WINDS LESS THAN 20 KNOTS. SEAS LESS THAN 5 FEET.
QUIET WEATHER.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR CTZ002>004.
MA...WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR MAZ017>021.
     WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR MAZ002>016-
     022>024-026.
RI...WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR RIZ002>008.
     WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR RIZ001.
MARINE...GALE WARNING FROM 11 AM MONDAY TO 4 AM EST TUESDAY FOR ANZ231-
     232-250-251-254-255.
     GALE WARNING FROM 11 AM TO 11 PM EST MONDAY FOR ANZ233>235-237-
     256.
     GALE WARNING FROM 11 AM TO 8 PM EST MONDAY FOR ANZ230-236.

&&

$$
SYNOPSIS...WTB/NMB
NEAR TERM...FRANK/DOODY/NMB
SHORT TERM...NMB
LONG TERM...WTB
AVIATION...WTB/NMB
MARINE...WTB/NMB




000
FXUS61 KGYX 012152
AFDGYX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
452 PM EST SUN MAR 1 2015

.SYNOPSIS...
LOW PRESSURE WILL MOVE EAST AND CROSS THE REGION OVERNIGHT...PRODUCING
SOME LIGHT SNOW. A STRONG NORTHWEST FLOW WILL SET UP IN ITS WAKE
ON MONDAY. HIGH PRESSURE WILL BUILD IN FROM THE WEST MONDAY NIGHT
AND WILL CREST OVER THE REGION EARLY TUESDAY BEFORE MOVING
OFFSHORE. LOW PRESSURE WILL SWING THROUGH SOUTHERN CANADA TUESDAY
NIGHT PUSHING A WARM FRONT NORTH ACROSS THE REGION...AND PRODUCING
A PERIOD OF SNOW AND MIXED RAIN OR SNOW ALONG THE COAST. AS THE
LOW SHIFTS TO OUR NORTH...IT WILL DRAG A COLD FRONT THROUGH THE
REGION LATE WEDNESDAY. HIGH PRESSURE WILL BUILD IN FROM THE WEST
THURSDAY AND WILL CREST OVER THE REGION ON FRIDAY.

&&

.NEAR TERM /TONIGHT/...
5PM UPDATE...
HAVE UPDATED PRECIPITATION CHANCES AND SNOWFALL FORECAST OVERNIGHT
AS MORE INTENSE ECHOES NOW SHOWING UP ON RADAR. BEST CHANCE AT
SEEING AN INCH OR TWO WILL BE NEAR THE COAST AND OVER SOUTHERN NEW
HAMPSHIRE WHERE AS MUCH AS 3 INCHES IS POSSIBLE.

ORIGINAL DISCUSSION...
SNOW WILL CONTINUE TO SPREAD EAST THIS EVENING IN ASSOCIATION
WITH BROAD SCALE WARM AIR ADVECTION PATTERN. SOME OF THIS
PRECIPITATION HOWEVER WILL CONTINUE TO SUBLIMATE AS IT INTERACTS
WITH A VERY DRY ATMOSPHERE OVER MAINE AND NEW HAMPSHIRE. EXPECT
PERIODS OF LIGHT SNOW OVERNIGHT. 12Z MODEL SUITE AND MESOSCALE
MODELS HAVE CONTINUED TO BACK OFF ON THE PRECIPITATION FIELDS AND
THEREFORE SNOWFALL AMOUNTS. NEVERTHELESS...THE HIGHEST TOTALS WILL
BE 3-4 INCHES ALONG PORTIONS OF THE MIDCOAST AND OVER FAR SOUTHERN
NH NEAR THE MASSACHUSETTS BORDER. THIS WILL BE JUST BELOW SNOW
ADVISORY CRITERIA.

IT WILL BE A MUCH MILDER NIGHT THAN THOSE OF THE LAST SEVERAL
NIGHTS WITH READINGS BETWEEN 15 AND 25 DEGREES FROM NORTH TO
SOUTH.

&&

.SHORT TERM /MONDAY AND MONDAY NIGHT/...
UPPER LEVEL SUPPORT REMAINS DISJOINTED FROM THE SURFACE
REFLECTION ON MONDAY...WITH THE SHORT WAVE CROSSING LAKE ONTARIO
BY EARLY MONDAY MORNING. THERE COULD BE A PASSING SNOW SHOWER WITH
THIS FEATURE. ACROSS THE NORTHWEST FACING HIGHER TERRAIN...SOME
UPSLOPING PRECIPITATION MAY OCCUR.

AS ARCTIC HIGH BUILDS OVER THE REGION...TEMPERATURES WILL ONCE
AGAIN DROP BELOW ZERO IN NORTHERN AREAS. WIND CHILL VALUES WILL BE
HEADING DOWNWARDS AGAIN AS WELL...BRIEFLY APPROACHING WIND CHILL
ADVISORY LEVELS IN THE MOUNTAINS.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
A SUNNY START ON TUESDAY AS HIGH PRESSURE IS CENTERED OVER THE
REGION. INCREASING HIGH CLOUDS WILL SPILL OVER THE SURFACE/UPPER
RIDGE IN THE AFTERNOON AS THE RIDGE AXIS MOVES OFF TO THE EAST.
TUESDAY NIGHT THE SOUTHWEST FLOW ALOFT WILL ALLOW A SHORT WAVE AND
ASSOCIATED WARM FRONT TO MOVE NORTH INTO NORTHERN NEW ENGLAND WITH
WIDESPREAD WARM AIR ADVECTION SNOW EXPECTED. MID/LOW LEVEL
TEMPERATURES SHOULD ALL BE COLD ENOUGH FOR SNOW EXCEPT ALONG THE
IMMEDIATE COAST WHERE A BRIEF MIX WITH RAIN MAY OCCUR BEFORE
ENDING EARLY WEDNESDAY MORNING. A BLEND OF MODELS QPF SUGGESTS A
SNOWFALL OF 2-6 INCHES EXPECTED. ON WEDNESDAY ALL MODELS INDICATE
THE SNOW TO BE OVER BY EARLY MORNING AND THEN SOME CLEARING AND
TEMPERATURES REACHING INTO THE 40S OVER MOST OF THE AREA AS H85
TEMPERATURES REMAIN MILD INTO THE AFTERNOON COMBINED WITH A
DEVELOPING LIGHT DOWNSLOPING WEST WIND. COLD AIR RETURNS FOR
WEDNESDAY NIGHT AND THURSDAY AS HIGH PRESSURE FROM THE GREAT LAKES
BUILDS EAST AND CONTINUES INTO FRIDAY. TEMPERATURES WILL RETURN TO
BELOW NORMAL FOR THURSDAY AND FRIDAY LIKE A BROKEN RECORD.

&&

.AVIATION /22Z SUNDAY THROUGH FRIDAY/...
SHORT TERM...CEILINGS AND VISIBILITIES GRADUALLY LOWERING AND
DIMINISHING THIS EVENING IN LIGHT SNOW. IFR CONDITIONS EXPECTED IN
MANY AREAS...ESPECIALLY OVER SOUTHERN LOCATIONS.

LONG TERM...
VFR TUESDAY BECOMING IFR TUESDAY NIGHT AND THEN A RETURN TO VFR
CONDITIONS FOR THE MID AND LATTER PART OF THE WEEK.

&&

.MARINE...
SHORT TERM...WILL BE ISSUING GALE WARNINGS FOR MONDAY AFTERNOON
THROUGH MONDAY EVENING FOR THE OUTER WATERS. WINDS WILL JUST TOUCH
GALE FORCE WELL AWAY FROM THE SHORELINE. ALONG THE BAYS...EXPECT
SMALL CRAFT ADVISORY TYPE WINDS INTO TOMORROW EVENING.

LONG TERM...
SCA`S MAY BE NEEDED IN THE SOUTH SOUTHWEST FLOW TUESDAY NIGHT.
THE SCA MAY ALSO BE NEEDED WEDNESDAY NIGHT AND THURSDAY WITH THE
NORTHWEST FLOW.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY FROM NOON TO 11 PM EST MONDAY FOR ANZ151-
     153.
     GALE WARNING FROM NOON TO 11 PM EST MONDAY FOR ANZ150-152-154.

&&

$$

NEAR TERM UPDATE...KIMBLE
SHORT TERM...CANNON
LONG TERM...MARINE
AVIATION...CANNON/MARINE
MARINE...CANNON/MARINE



000
FXUS61 KGYX 012152
AFDGYX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
452 PM EST SUN MAR 1 2015

.SYNOPSIS...
LOW PRESSURE WILL MOVE EAST AND CROSS THE REGION OVERNIGHT...PRODUCING
SOME LIGHT SNOW. A STRONG NORTHWEST FLOW WILL SET UP IN ITS WAKE
ON MONDAY. HIGH PRESSURE WILL BUILD IN FROM THE WEST MONDAY NIGHT
AND WILL CREST OVER THE REGION EARLY TUESDAY BEFORE MOVING
OFFSHORE. LOW PRESSURE WILL SWING THROUGH SOUTHERN CANADA TUESDAY
NIGHT PUSHING A WARM FRONT NORTH ACROSS THE REGION...AND PRODUCING
A PERIOD OF SNOW AND MIXED RAIN OR SNOW ALONG THE COAST. AS THE
LOW SHIFTS TO OUR NORTH...IT WILL DRAG A COLD FRONT THROUGH THE
REGION LATE WEDNESDAY. HIGH PRESSURE WILL BUILD IN FROM THE WEST
THURSDAY AND WILL CREST OVER THE REGION ON FRIDAY.

&&

.NEAR TERM /TONIGHT/...
5PM UPDATE...
HAVE UPDATED PRECIPITATION CHANCES AND SNOWFALL FORECAST OVERNIGHT
AS MORE INTENSE ECHOES NOW SHOWING UP ON RADAR. BEST CHANCE AT
SEEING AN INCH OR TWO WILL BE NEAR THE COAST AND OVER SOUTHERN NEW
HAMPSHIRE WHERE AS MUCH AS 3 INCHES IS POSSIBLE.

ORIGINAL DISCUSSION...
SNOW WILL CONTINUE TO SPREAD EAST THIS EVENING IN ASSOCIATION
WITH BROAD SCALE WARM AIR ADVECTION PATTERN. SOME OF THIS
PRECIPITATION HOWEVER WILL CONTINUE TO SUBLIMATE AS IT INTERACTS
WITH A VERY DRY ATMOSPHERE OVER MAINE AND NEW HAMPSHIRE. EXPECT
PERIODS OF LIGHT SNOW OVERNIGHT. 12Z MODEL SUITE AND MESOSCALE
MODELS HAVE CONTINUED TO BACK OFF ON THE PRECIPITATION FIELDS AND
THEREFORE SNOWFALL AMOUNTS. NEVERTHELESS...THE HIGHEST TOTALS WILL
BE 3-4 INCHES ALONG PORTIONS OF THE MIDCOAST AND OVER FAR SOUTHERN
NH NEAR THE MASSACHUSETTS BORDER. THIS WILL BE JUST BELOW SNOW
ADVISORY CRITERIA.

IT WILL BE A MUCH MILDER NIGHT THAN THOSE OF THE LAST SEVERAL
NIGHTS WITH READINGS BETWEEN 15 AND 25 DEGREES FROM NORTH TO
SOUTH.

&&

.SHORT TERM /MONDAY AND MONDAY NIGHT/...
UPPER LEVEL SUPPORT REMAINS DISJOINTED FROM THE SURFACE
REFLECTION ON MONDAY...WITH THE SHORT WAVE CROSSING LAKE ONTARIO
BY EARLY MONDAY MORNING. THERE COULD BE A PASSING SNOW SHOWER WITH
THIS FEATURE. ACROSS THE NORTHWEST FACING HIGHER TERRAIN...SOME
UPSLOPING PRECIPITATION MAY OCCUR.

AS ARCTIC HIGH BUILDS OVER THE REGION...TEMPERATURES WILL ONCE
AGAIN DROP BELOW ZERO IN NORTHERN AREAS. WIND CHILL VALUES WILL BE
HEADING DOWNWARDS AGAIN AS WELL...BRIEFLY APPROACHING WIND CHILL
ADVISORY LEVELS IN THE MOUNTAINS.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
A SUNNY START ON TUESDAY AS HIGH PRESSURE IS CENTERED OVER THE
REGION. INCREASING HIGH CLOUDS WILL SPILL OVER THE SURFACE/UPPER
RIDGE IN THE AFTERNOON AS THE RIDGE AXIS MOVES OFF TO THE EAST.
TUESDAY NIGHT THE SOUTHWEST FLOW ALOFT WILL ALLOW A SHORT WAVE AND
ASSOCIATED WARM FRONT TO MOVE NORTH INTO NORTHERN NEW ENGLAND WITH
WIDESPREAD WARM AIR ADVECTION SNOW EXPECTED. MID/LOW LEVEL
TEMPERATURES SHOULD ALL BE COLD ENOUGH FOR SNOW EXCEPT ALONG THE
IMMEDIATE COAST WHERE A BRIEF MIX WITH RAIN MAY OCCUR BEFORE
ENDING EARLY WEDNESDAY MORNING. A BLEND OF MODELS QPF SUGGESTS A
SNOWFALL OF 2-6 INCHES EXPECTED. ON WEDNESDAY ALL MODELS INDICATE
THE SNOW TO BE OVER BY EARLY MORNING AND THEN SOME CLEARING AND
TEMPERATURES REACHING INTO THE 40S OVER MOST OF THE AREA AS H85
TEMPERATURES REMAIN MILD INTO THE AFTERNOON COMBINED WITH A
DEVELOPING LIGHT DOWNSLOPING WEST WIND. COLD AIR RETURNS FOR
WEDNESDAY NIGHT AND THURSDAY AS HIGH PRESSURE FROM THE GREAT LAKES
BUILDS EAST AND CONTINUES INTO FRIDAY. TEMPERATURES WILL RETURN TO
BELOW NORMAL FOR THURSDAY AND FRIDAY LIKE A BROKEN RECORD.

&&

.AVIATION /22Z SUNDAY THROUGH FRIDAY/...
SHORT TERM...CEILINGS AND VISIBILITIES GRADUALLY LOWERING AND
DIMINISHING THIS EVENING IN LIGHT SNOW. IFR CONDITIONS EXPECTED IN
MANY AREAS...ESPECIALLY OVER SOUTHERN LOCATIONS.

LONG TERM...
VFR TUESDAY BECOMING IFR TUESDAY NIGHT AND THEN A RETURN TO VFR
CONDITIONS FOR THE MID AND LATTER PART OF THE WEEK.

&&

.MARINE...
SHORT TERM...WILL BE ISSUING GALE WARNINGS FOR MONDAY AFTERNOON
THROUGH MONDAY EVENING FOR THE OUTER WATERS. WINDS WILL JUST TOUCH
GALE FORCE WELL AWAY FROM THE SHORELINE. ALONG THE BAYS...EXPECT
SMALL CRAFT ADVISORY TYPE WINDS INTO TOMORROW EVENING.

LONG TERM...
SCA`S MAY BE NEEDED IN THE SOUTH SOUTHWEST FLOW TUESDAY NIGHT.
THE SCA MAY ALSO BE NEEDED WEDNESDAY NIGHT AND THURSDAY WITH THE
NORTHWEST FLOW.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY FROM NOON TO 11 PM EST MONDAY FOR ANZ151-
     153.
     GALE WARNING FROM NOON TO 11 PM EST MONDAY FOR ANZ150-152-154.

&&

$$

NEAR TERM UPDATE...KIMBLE
SHORT TERM...CANNON
LONG TERM...MARINE
AVIATION...CANNON/MARINE
MARINE...CANNON/MARINE




000
FXUS61 KBOX 012106
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
406 PM EST SUN MAR 1 2015

.SYNOPSIS...
A FAST MOVING LOW PRESSURE SYSTEM WILL BRING ACCUMULATING SNOW
LATER TODAY AND ESPECIALLY TONIGHT WITH THE HIGHEST AMOUNTS
EXPECTED SOUTH OF THE MASSACHUSETTS TURNPIKE. HIGH PRESSURE
BRINGS DRY COLD AIR FOR THE EARLY WEEK. LOW PRESSURE FROM NORTHERN
CANADA AND ASSOCIATED LOW FORMING OVER THE PLAINS MONDAY WILL
MERGE...THEN PASS WEST AND NORTH OF NEW ENGLAND. THIS WILL SWING A
COLD FRONT ACROSS THE REGION ON WEDNESDAY. DRY AND COLD WEATHER
RETURNS FOR THE END OF THE WEEK. ANOTHER COLD FRONT MOVES THROUGH
ON SATURDAY.

&&

.NEAR TERM /UNTIL 5 PM THIS AFTERNOON/...
1 PM UPDATE...

LIGHT SNOW IS WORKING ITS WAY INTO SOUTHERN NEW ENGLAND...BASED ON
18Z OBS LIGHT SNOW HAS MADE IT INTO THE SPRINGFIELD AREA AND LIGHT
SNOW HAS EVEN STARTED AT PVD. THE SNOW WILL CONTINUE TO GRADUALLY
OVERSPREAD THE REMAINDER OF OUR AREA AS THE AFTERNOON
PROGRESSES...LIKELY REACHING BOSTON AROUND 20Z. AGAIN ONLY MINOR CHANGES
MADE TO HOURLY TEMPS TO REFLECT LATEST OBS...FORECAST HIGHS
CONTINUE TO LOOK ON TRACK.

EARLY MORNING DISCUSSION...

MID LEVEL CLOUDINESS WILL STREAM INTO SOUTHERN NEW ENGLAND AND
THICKEN DURING THE MORNING HOURS IN ADVANCE OF APPROACHING LOW
PRESSURE.  SOUTHWEST FLOW ALOFT OVERRUNING THE COLD DOME AT THE
SURFACE MAY ALLOW FOR SOME LIGHT SNOW/FLURRIES TO BREAK
OUT ACROSS THE INTERIOR LATE THIS MORNING/EARLY AFTERNOON AND THEN
FIND THEIR WAY TO THE COAST BY MID TO LATE AFTERNOON.  THE LIFT
THROUGH MID AFTERNOON IS FAIRLY WEAK...SO THE AREAS OF SNOW SHOULD
BE RATHER LIGHT. ANY ACCUMULATIONS THAT OCCUR WILL PROBABLY BE
A DUSTING TO LESS THAN 1 INCH THROUGH THAT THAT TIME.  HIGH TEMPS
WILL MAINLY BE IN THE UPPER 20S TO AROUND 30.

&&

.SHORT TERM /5 PM THIS AFTERNOON THROUGH MONDAY NIGHT/...
*** BULK OF THE ACCUMULATING SNOW OCCURS BETWEEN 3 PM AND 1 AM WITH
  THE HEAVIEST AMOUNTS SOUTH OF THE MA TURNPIKE ***

1) OVERVIEW AND TIMING:

THE BULK OF THE ACCUMULATING SNOW WILL OCCUR BETWEEN 3 PM AND
1 AM ACROSS THE REGION.  THE SNOW SHOULD TAPER OFF TO FLURRIES
TOWARD DAYBREAK MONDAY.  THE MODELS DO AGREE THAT THE BETTER FORCING
WILL OCCUR TO THE SOUTH OF THE MA TURNPIKE.  THIS A RESULT
OF SECONDARY LOW PRESSURE NEAR THE SOUTH COAST...ALLOWING FOR
SOME SURFACE CONVERGENCE AS WELL AS THE INTENSIFICATION OF THE LOW
LEVEL JET.

THE BIGGEST ISSUE IS THE MODELS ARE NOT IN AGREEMENT IN HOW
INTENSE THE FORCING WILL BE ACROSS THE REGION THIS EVENING.  THE
RGEM/NAM ARE THE MOST ROBUST WITH QPF SOUTH OF THE MA TURNPIKE.  THE
NAM SHOWS A PERIOD OF FAIRLY STRONG LIFT OF 15 TO 20 MICROBARS PER
SECOND WITHIN THE BEST SNOWGROWTH REGION THIS EVENING.  THIS WOULD
TRANSLATE TO A PERIOD OF 1+ INCH PER HOUR SNOWFALL RATES NEAR AND
SOUTH OF THE MA PIKE.  ON THE OTHER HAND...THE GFS ALSO HAS FAIRLY
STRONG LIFT...BUT KEEPS IT SOUTHEAST OF OUR REGION OUT OVER THE
OCEAN.  THE SECONDARY LOW PRESSURE SYSTEM ON THE GFS IS WEAKER AND
FURTHER SOUTHEAST...RESULTING IN THE LOW LEVEL JET BEING DISPLACED
FURTHER EAST.  THE ECMWF/UKMET SOLUTIONS SEEM TO BE THE MIDDLE
GROUND WHICH WE WILL LEAN TOWARDS.

2) WINTER WEATHER HEADLINES AND SNOW ACCUMS:

WITH THAT SAID...THE OTHER DILEMMA IS WHAT TO DO WITH THE CURRENT
HEADLINES.  THIS DOES NOT APPEAR TO BE THE TYPE OF SETUP WHERE WE
ARE GOING TO RECEIVE WIDESPREAD WARNING SNOWFALL AMOUNTS.  THE
WINDOW FOR THE VERY STRONG LIFT/FORCING IS SHORT-LIVED AND REALLY
WOULD LIKE TO SEE THE LOW LEVEL JET A BIT MORE BACKED TO TRANSPORT
DEEPER MOISTURE NORTHWARD.  THEREFORE...FEEL THAT FOR MOST OF THE
REGION WINTER WEATHER ADVISORY/S FOR 3 TO 6 INCHES OF SNOW WILL
COVER IT.  HOWEVER...GIVEN THERE IS NICE OMEGA IN THE SNOW GROWTH
REGION...WE MIGHT BE LOOKING AT SOME DECENT RATIOS.  SO WE STILL CAN
NOT RULE OUT THE LOW RISK OF REACHING WARNING AMOUNTS AND LATER
SHIFTS WILL HAVE TO MONITOR CLOSELY...ESPECIALLY ACROSS NORTHERN CT
AND NORTHWEST RI.

WE DID UPGRADE A SMALL AREA FROM CENTRAL AND SOUTHERN RHODE ISLAND
INTO SOUTHEAST MA INCLUDING THE SOUTH COAST TO A WINTER
STORM WARNING.  THE NOSE OF THE LOW LEVEL JET LOOKS TO TRANSPORT
SOME DEEPER MOISTURE INTO THIS REGION.  THERE ALSO COULD BE SOME
ENHANCEMENT ALONG THE LAND/SEA INTERFACE AND A WEAK SURFACE
BOUNDARY SO WENT WITH 4 TO 8 INCHES IN THIS REGION.

3) PTYPE AND IMPACTS:

THE MODELS HAVE TRENDED COLDER OVER THE PAST 24 HOURS.
THEREFORE...EXPECT THIS BE PRETTY MUCH A SNOW EVENT.  IT DOES BECOME
A VERY CLOSE CALL NEAR THE SOUTH COAST...BUT WERE LEANING TOWARDS IT
STAYING MAINLY WET SNOW.  IF PRECIPITATION LIGHTENS UP THAT MAY
INCREASE THIS RISK WE SEE A BRIEF CHANGE OVER TO RAIN.
MEANWHILE...WE WENT WITH A HIGH END WINTER WEATHER ADVISORY FOR THE
CAPE BECAUSE THEY MAY CHANGE TO RAIN FOR A TIME...ESPECIALLY EAST OF
HYANNIS.  IF THE CHANGE OVER DOES NOT OCCUR...WE MAY NEED TO UPGRADE
THEM TO A WINTER STORM WARNING ESPECIALLY NEAR THE CAPE COD CANAL
GIVEN EXPECTED QPF.

THE ONE THING WILL ALSO HAVE TO WATCH IS AREAS NEAR THE SOUTH COAST
AND CAPE COD.  LOOKS TO BE A WET SNOW DOWN THAT WAY AND ON GOING
ROOF ISSUES MAY BE EXACERBATED...ESPECIALLY IF ANY AREAS THAT ARE
ABLE TO EXCEED 6 INCHES OF WET SNOW.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...

BIG PICTURE... THE BROAD UPPER FLOW CONTINUES TO FEATURE A TROUGH
TRANSITING EAST ACROSS THE COUNTRY...REACHING THE EASTERN USA DURING
THE LATE WEEK AND LINGERING THROUGH THE WEEKEND. MEANWHILE AN UPPER
RIDGE SHIFTS FROM THE PACIFIC OCEAN BACK ASHORE ONTO THE WEST COAST.
CONTOUR HEIGHTS IN THE TROUGH ARE LOWEST THURSDAY-FRIDAY AND NEAR
NORMAL OVER THE WEEKEND. THIS MEANS A TREND TO COLDER TEMPS THURSDAY-
FRIDAY FOLLOWED BY A TREND CLOSER TO NORMAL OVER THE WEEKEND.

DAILIES...

TUESDAY... HIGH PRESSURE OVER THE REGION MOVES OFFSHORE BY AFTERNOON
WITH AIRFLOW SWINGING FROM NORTHWEST TO SOUTHWEST. THE SURFACE
AIRMASS STARTS OUT QUITE DRY WITH DEW POINTS IN THE SINGLE NUMBERS
BELOW ZERO TO START...CLIMBING TO 5-10 ABOVE BY EVENING. MODEL CROSS
SECTIONS SHOW INCREASING MOISTURE MORNING AND AFTERNOON ABOVE 700
MB. THIS SUGGESTS INCREASING MID AND HIGH CLOUDS WHILE DRY BENEATH.
LOW LEVEL JETS FROM THE CAROLINAS AND MIDWEST AND THE SURFACE
PRESSURE GRADIENT ALL SUGGEST THE INFLOW AND ISENTROPIC LIFT WILL
REMAIN TO OUR WEST THROUGH THE DAY...POSSIBLY ENTERING WESTERN MA/CT
AT OR AFTER 21Z. SO WE EXPECT INCREASING CLOUDS TUESDAY BUT
OTHERWISE DRY WEATHER THROUGH THE DAY. POSSIBLE LIGHT SNOW AROUND
THE EVENING RUSH HOUR IN THE CT RIVER VALLEY. TEMPS SHOULD REACH THE
MID 20S TO AROUND 30.

TUESDAY NIGHT-WEDNESDAY... NORTHERN AND SOUTHERN STREAM SHORTWAVES
MERGE OVER THE GREAT LAKES AND TRACK INTO CANADA. THIS BRINGS A MILD
FLOW OF AIR UP OVER NEW ENGLAND. THE LEADING EDGE OF THIS AIR
REACHES WESTERN SECTIONS TUESDAY EVENING AND EASTERN SECTIONS
TUESDAY NIGHT. TEMPERATURE PROFILES SUPPORT AN INITIAL PERIOD OF
SNOW CHANGING TO RAIN OR FREEZING RAIN OVERNIGHT. ACTUALLY...THE
MODELS MAY NOT BE HANDLING WELL THE CHILLING MASS OF SNOW AND COLD
GROUND /A.K.A. THE GIANT ICECUBE/ WHICH WOULD MEAN THE ACTUAL MAX
SFC TEMPS WILL BE COOLER THAN MODEL FORECASTS. TEMPERATURES AT 925
AND 950 MB WILL BE IN THE 30S...SO EXPECT SURFACE TEMPS NO HIGHER
THAN THE LOWER 40S.

THE SURFACE LOW PRESSURE AREA PASSES WELL NORTH OF NEW ENGLAND
WEDNESDAY AND SWINGS A COLD FRONT THROUGH THE REGION DURING THE
AFTERNOON OR EVENING. MOISTURE CROSS SECTIONS SHOW DECREASING RH IN
THE LIFT AND NUCLEATION ZONES ALOFT WEDNESDAY MORNING...SO THE TREND
THROUGH THE DAY SHOULD BE TO DIMINISHING POPS.

THURSDAY-FRIDAY... THE WEDNESDAY COLD FRONT WILL ALIGN WITH THE
UPPER FLOW AS IT MOVES SOUTH OF NEW ENGLAND...SLOWING ITS OFFSHORE
PROGRESS TO A CRAWL. MEANWHILE WE WILL BE UNDER THE RIGHT ENTRANCE
REGION OF THE SUPPORTING UPPER JET...A SOURCE OF UPPER VENTING. THIS
SHOULD SUPPORT LINGERING CLOUDS AND A CHANCE OF PCPN...WITH TEMPS
SUPPORTIVE OF SNOW. BEST CHANCE SOUTH COAST...LESSER CHANCE FARTHER
NORTH. THE JET AND SURFACE FRONT SWEEP OFFSHORE THURSDAY NIGHT. HIGH
PRESSURE THEN MOVES OVER THE EASTERN USA FOR FRIDAY. TEMPS ALOFT
SUPPORT MAX SFC TEMPS IN THE 20S.

SATURDAY-SUNDAY... ANOTHER NORTHERN STREAM SHORTWAVE AND COLD FRONT
SWINGS THROUGH THE FLOW SATURDAY. CROSS SECTIONS SHOW SOME MOISTURE
ALOFT BUT MOST OF IT IS CONCENTRATED TO OUR NORTH.  ALSO JUST
LIMITED LIFT TO WORK ON THAT MOISTURE. WE WILL HAVE 25-50 PCT SKY
COVER AND NIL POPS. HIGH PRESSURE THEN BUILDS FOR SUNDAY.

&&

.AVIATION /21Z SUNDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TODAY AND TONIGHT/...

18Z UPDATE...MODERATE CONFIDENCE.

THIS AFTERNOON...MVFR CIGS/VSBYS IN LIGHT SNOW AT BAF-BDL BUT MAINLY
VFR TO THE EAST TO START...WITH CIGS AND/OR VSBYS LOWERING TO MVFR
ACROSS THE REMAINDER OF SOUTHERN NEW ENGLAND TERMINALS BETWEEN
18Z AND 21Z IN LIGHT SNOW.

TONIGHT...MODERATE CONFIDENCE. THE BULK OF THE MODERATE TO EVEN
BRIEFLY HEAVY SNOW WILL OCCUR THIS EVENING WHEN WIDESPREAD IFR TO
LIFR CONDITIONS OCCUR. THE LOWEST CONDITIONS WILL MOST LIKELY BE
SOUTH OF THE MA TURNPIKE. PTYPE PRETTY MUCH ALL SNOW...EXCEPT FOR
THE VERY IMMEDIATE SOUTH COAST/CAPE WHERE SNOW MAY MIX WITH OR
CHANGE TO RAIN FOR A TIME. WHETHER OR NOT THAT HAPPENS IS
UNCERTAIN...BUT WE DO THINK THAT AT LEAST THE ISLANDS WILL MIX OR CHANGE
TO RAIN.

BULK OF SNOW ENDS BY 8Z TO 9Z TONIGHT AND MUCH OF THE THE REGION
SHOULD IMPROVE TO VFR CONDITIONS BY 12-13Z MONDAY.

KBOS TAF...CONFIDENT IN OVERALL TRENDS BUT THERE IS UNCERTAINTY ON
TIMING. SOME LIGHT SNOW IS EXPECTED DURING MID TO LATE
AFTERNOON...BUT THE BULK OF ACCUMULATING SNOW WITH IFR TO LIFR
CONDITIONS EXPECTED MAINLY THIS EVENING.

KBDL TAF...CONFIDENT IN OVERALL TRENDS BUT THERE IS UNCERTAINTY ON
TIMING. BULK OF ACCUMULATING SNOW WITH IFR TO LIFR CONDITIONS
EXPECTED AFTER 3 OR 4 PM.

OUTLOOK...TUESDAY THROUGH FRIDAY...

TUESDAY...MODERATE CONFIDENCE. VFR DURING THE DAY WITH INCREASING
SKY COVER. MVFR CIGS/VSBYS POSSIBLE LATE IN THE DAY CT RIVER VALLEY.

TUESDAY NIGHT-WEDNESDAY...MODERATE CONFIDENCE. CONDITIONS LOWERING
TO IFR/LIFR. INITIALLY SNOW BUT CHANGING TO SLEET/FREEZING RAIN
DURING THE NIGHT AND RAIN IN THE COASTAL PLAIN OVERNIGHT. PCPN
CHANGES TO RAIN ALL AREAS WEDNESDAY...BUT COLD SURFACES COULD
MAINTAIN A FREEZING RAIN ELEMENT WEDNESDAY MORNING. COLDER AIR MOVES
IN WEDNESDAY NIGHT CHANGING ANY RAIN TO SNOW.

THURSDAY...LOW CONFIDENCE. VFR NORTH OF A HFD-BOS LINE. MVFR CIGS
AND AREAS OF MVFR/IFR VSBYS IN SNOW...DIMINISHING BY EVENING.
NORTHWEST WINDS GUSTING TO 20 KNOTS.

FRIDAY...MODERATE CONFIDENCE. VFR.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TODAY AND TONIGHT/...HIGH CONFIDENCE.

A WEAK WAVE OF LOW PRESSURE MOVES ACROSS THE WATERS LATER
TODAY AND TONIGHT.  WEAK PRESSURE GRADIENT SHOULD KEEP
WINDS/SEAS BELOW SMALL CRAFT THRESHOLDS TODAY AND TONIGHT.  THE
SYSTEM REALLY INTENSIFIES AS IT MOVES INTO THE CANADIAN MARITIMES
NEAR DAYBREAK MONDAY...SO WESTERLY WIND GUSTS MAY REACH 20 TO 25
KNOTS NEAR 12Z MONDAY.  OTHERWISE...RAIN AND SNOW LATE TODAY AND
ESPECIALLY TONIGHT WILL REDUCE VISIBILITIES AT TIMES FOR MARINERS.

OUTLOOK...TUESDAY THROUGH FRIDAY..MODERATE CONFIDENCE.

TUESDAY... LINGERING 5 FOOT SEAS SOUTH AND EAST OF NANTUCKET IN THE
MORNING BUT DIMINISHING. NORTHWEST WINDS DIMINISHING FROM 20 KNOTS.
ANY SMALL CRAFT ADVISORY SHOULD END IN THE MORNING.

TUESDAY NIGHT-WEDNESDAY...SOUTH TO SOUTHWEST WINDS WILL INCREASE TO
20-25 KNOTS. SEAS WILL BUILD 6 TO 10 FEET ON THE OUTER WATERS AND ON
RI SOUND. REDUCED VSBYS...INITIALLY SNOW BUT CHANGING TO RAIN. A
SMALL CRAFT ADVISORY MAY BE NEEDED.

THURSDAY...NORTHWEST WIND GUSTING TO 25 KNOTS. SEAS 5 TO 8 FEET
MAINLY ON THE OUTER WATERS...DIMINISHING LATE. A SMALL CRAFT
ADVISORY MAY BE NEEDED.

FRIDAY... SHIFTING WINDS LESS THAN 20 KNOTS. SEAS LESS THAN 5 FEET.
QUIET WEATHER.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR CTZ002>004.
MA...WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR MAZ017>021.
     WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR MAZ002>016-
     022>024-026.
RI...WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR RIZ002>008.
     WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR RIZ001.
MARINE...GALE WARNING FROM 11 AM MONDAY TO 4 AM EST TUESDAY FOR ANZ231-
     232-250-251-254-255.
     GALE WARNING FROM 11 AM TO 11 PM EST MONDAY FOR ANZ233>235-237-
     256.
     GALE WARNING FROM 11 AM TO 8 PM EST MONDAY FOR ANZ230-236.

&&

$$
SYNOPSIS...WTB/FRANK
NEAR TERM...FRANK/DOODY/NMB
SHORT TERM...FRANK
LONG TERM...WTB
AVIATION...WTB/FRANK/NMB
MARINE...WTB/FRANK




000
FXUS61 KBOX 012106
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
406 PM EST SUN MAR 1 2015

.SYNOPSIS...
A FAST MOVING LOW PRESSURE SYSTEM WILL BRING ACCUMULATING SNOW
LATER TODAY AND ESPECIALLY TONIGHT WITH THE HIGHEST AMOUNTS
EXPECTED SOUTH OF THE MASSACHUSETTS TURNPIKE. HIGH PRESSURE
BRINGS DRY COLD AIR FOR THE EARLY WEEK. LOW PRESSURE FROM NORTHERN
CANADA AND ASSOCIATED LOW FORMING OVER THE PLAINS MONDAY WILL
MERGE...THEN PASS WEST AND NORTH OF NEW ENGLAND. THIS WILL SWING A
COLD FRONT ACROSS THE REGION ON WEDNESDAY. DRY AND COLD WEATHER
RETURNS FOR THE END OF THE WEEK. ANOTHER COLD FRONT MOVES THROUGH
ON SATURDAY.

&&

.NEAR TERM /UNTIL 5 PM THIS AFTERNOON/...
1 PM UPDATE...

LIGHT SNOW IS WORKING ITS WAY INTO SOUTHERN NEW ENGLAND...BASED ON
18Z OBS LIGHT SNOW HAS MADE IT INTO THE SPRINGFIELD AREA AND LIGHT
SNOW HAS EVEN STARTED AT PVD. THE SNOW WILL CONTINUE TO GRADUALLY
OVERSPREAD THE REMAINDER OF OUR AREA AS THE AFTERNOON
PROGRESSES...LIKELY REACHING BOSTON AROUND 20Z. AGAIN ONLY MINOR CHANGES
MADE TO HOURLY TEMPS TO REFLECT LATEST OBS...FORECAST HIGHS
CONTINUE TO LOOK ON TRACK.

EARLY MORNING DISCUSSION...

MID LEVEL CLOUDINESS WILL STREAM INTO SOUTHERN NEW ENGLAND AND
THICKEN DURING THE MORNING HOURS IN ADVANCE OF APPROACHING LOW
PRESSURE.  SOUTHWEST FLOW ALOFT OVERRUNING THE COLD DOME AT THE
SURFACE MAY ALLOW FOR SOME LIGHT SNOW/FLURRIES TO BREAK
OUT ACROSS THE INTERIOR LATE THIS MORNING/EARLY AFTERNOON AND THEN
FIND THEIR WAY TO THE COAST BY MID TO LATE AFTERNOON.  THE LIFT
THROUGH MID AFTERNOON IS FAIRLY WEAK...SO THE AREAS OF SNOW SHOULD
BE RATHER LIGHT. ANY ACCUMULATIONS THAT OCCUR WILL PROBABLY BE
A DUSTING TO LESS THAN 1 INCH THROUGH THAT THAT TIME.  HIGH TEMPS
WILL MAINLY BE IN THE UPPER 20S TO AROUND 30.

&&

.SHORT TERM /5 PM THIS AFTERNOON THROUGH MONDAY NIGHT/...
*** BULK OF THE ACCUMULATING SNOW OCCURS BETWEEN 3 PM AND 1 AM WITH
  THE HEAVIEST AMOUNTS SOUTH OF THE MA TURNPIKE ***

1) OVERVIEW AND TIMING:

THE BULK OF THE ACCUMULATING SNOW WILL OCCUR BETWEEN 3 PM AND
1 AM ACROSS THE REGION.  THE SNOW SHOULD TAPER OFF TO FLURRIES
TOWARD DAYBREAK MONDAY.  THE MODELS DO AGREE THAT THE BETTER FORCING
WILL OCCUR TO THE SOUTH OF THE MA TURNPIKE.  THIS A RESULT
OF SECONDARY LOW PRESSURE NEAR THE SOUTH COAST...ALLOWING FOR
SOME SURFACE CONVERGENCE AS WELL AS THE INTENSIFICATION OF THE LOW
LEVEL JET.

THE BIGGEST ISSUE IS THE MODELS ARE NOT IN AGREEMENT IN HOW
INTENSE THE FORCING WILL BE ACROSS THE REGION THIS EVENING.  THE
RGEM/NAM ARE THE MOST ROBUST WITH QPF SOUTH OF THE MA TURNPIKE.  THE
NAM SHOWS A PERIOD OF FAIRLY STRONG LIFT OF 15 TO 20 MICROBARS PER
SECOND WITHIN THE BEST SNOWGROWTH REGION THIS EVENING.  THIS WOULD
TRANSLATE TO A PERIOD OF 1+ INCH PER HOUR SNOWFALL RATES NEAR AND
SOUTH OF THE MA PIKE.  ON THE OTHER HAND...THE GFS ALSO HAS FAIRLY
STRONG LIFT...BUT KEEPS IT SOUTHEAST OF OUR REGION OUT OVER THE
OCEAN.  THE SECONDARY LOW PRESSURE SYSTEM ON THE GFS IS WEAKER AND
FURTHER SOUTHEAST...RESULTING IN THE LOW LEVEL JET BEING DISPLACED
FURTHER EAST.  THE ECMWF/UKMET SOLUTIONS SEEM TO BE THE MIDDLE
GROUND WHICH WE WILL LEAN TOWARDS.

2) WINTER WEATHER HEADLINES AND SNOW ACCUMS:

WITH THAT SAID...THE OTHER DILEMMA IS WHAT TO DO WITH THE CURRENT
HEADLINES.  THIS DOES NOT APPEAR TO BE THE TYPE OF SETUP WHERE WE
ARE GOING TO RECEIVE WIDESPREAD WARNING SNOWFALL AMOUNTS.  THE
WINDOW FOR THE VERY STRONG LIFT/FORCING IS SHORT-LIVED AND REALLY
WOULD LIKE TO SEE THE LOW LEVEL JET A BIT MORE BACKED TO TRANSPORT
DEEPER MOISTURE NORTHWARD.  THEREFORE...FEEL THAT FOR MOST OF THE
REGION WINTER WEATHER ADVISORY/S FOR 3 TO 6 INCHES OF SNOW WILL
COVER IT.  HOWEVER...GIVEN THERE IS NICE OMEGA IN THE SNOW GROWTH
REGION...WE MIGHT BE LOOKING AT SOME DECENT RATIOS.  SO WE STILL CAN
NOT RULE OUT THE LOW RISK OF REACHING WARNING AMOUNTS AND LATER
SHIFTS WILL HAVE TO MONITOR CLOSELY...ESPECIALLY ACROSS NORTHERN CT
AND NORTHWEST RI.

WE DID UPGRADE A SMALL AREA FROM CENTRAL AND SOUTHERN RHODE ISLAND
INTO SOUTHEAST MA INCLUDING THE SOUTH COAST TO A WINTER
STORM WARNING.  THE NOSE OF THE LOW LEVEL JET LOOKS TO TRANSPORT
SOME DEEPER MOISTURE INTO THIS REGION.  THERE ALSO COULD BE SOME
ENHANCEMENT ALONG THE LAND/SEA INTERFACE AND A WEAK SURFACE
BOUNDARY SO WENT WITH 4 TO 8 INCHES IN THIS REGION.

3) PTYPE AND IMPACTS:

THE MODELS HAVE TRENDED COLDER OVER THE PAST 24 HOURS.
THEREFORE...EXPECT THIS BE PRETTY MUCH A SNOW EVENT.  IT DOES BECOME
A VERY CLOSE CALL NEAR THE SOUTH COAST...BUT WERE LEANING TOWARDS IT
STAYING MAINLY WET SNOW.  IF PRECIPITATION LIGHTENS UP THAT MAY
INCREASE THIS RISK WE SEE A BRIEF CHANGE OVER TO RAIN.
MEANWHILE...WE WENT WITH A HIGH END WINTER WEATHER ADVISORY FOR THE
CAPE BECAUSE THEY MAY CHANGE TO RAIN FOR A TIME...ESPECIALLY EAST OF
HYANNIS.  IF THE CHANGE OVER DOES NOT OCCUR...WE MAY NEED TO UPGRADE
THEM TO A WINTER STORM WARNING ESPECIALLY NEAR THE CAPE COD CANAL
GIVEN EXPECTED QPF.

THE ONE THING WILL ALSO HAVE TO WATCH IS AREAS NEAR THE SOUTH COAST
AND CAPE COD.  LOOKS TO BE A WET SNOW DOWN THAT WAY AND ON GOING
ROOF ISSUES MAY BE EXACERBATED...ESPECIALLY IF ANY AREAS THAT ARE
ABLE TO EXCEED 6 INCHES OF WET SNOW.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...

BIG PICTURE... THE BROAD UPPER FLOW CONTINUES TO FEATURE A TROUGH
TRANSITING EAST ACROSS THE COUNTRY...REACHING THE EASTERN USA DURING
THE LATE WEEK AND LINGERING THROUGH THE WEEKEND. MEANWHILE AN UPPER
RIDGE SHIFTS FROM THE PACIFIC OCEAN BACK ASHORE ONTO THE WEST COAST.
CONTOUR HEIGHTS IN THE TROUGH ARE LOWEST THURSDAY-FRIDAY AND NEAR
NORMAL OVER THE WEEKEND. THIS MEANS A TREND TO COLDER TEMPS THURSDAY-
FRIDAY FOLLOWED BY A TREND CLOSER TO NORMAL OVER THE WEEKEND.

DAILIES...

TUESDAY... HIGH PRESSURE OVER THE REGION MOVES OFFSHORE BY AFTERNOON
WITH AIRFLOW SWINGING FROM NORTHWEST TO SOUTHWEST. THE SURFACE
AIRMASS STARTS OUT QUITE DRY WITH DEW POINTS IN THE SINGLE NUMBERS
BELOW ZERO TO START...CLIMBING TO 5-10 ABOVE BY EVENING. MODEL CROSS
SECTIONS SHOW INCREASING MOISTURE MORNING AND AFTERNOON ABOVE 700
MB. THIS SUGGESTS INCREASING MID AND HIGH CLOUDS WHILE DRY BENEATH.
LOW LEVEL JETS FROM THE CAROLINAS AND MIDWEST AND THE SURFACE
PRESSURE GRADIENT ALL SUGGEST THE INFLOW AND ISENTROPIC LIFT WILL
REMAIN TO OUR WEST THROUGH THE DAY...POSSIBLY ENTERING WESTERN MA/CT
AT OR AFTER 21Z. SO WE EXPECT INCREASING CLOUDS TUESDAY BUT
OTHERWISE DRY WEATHER THROUGH THE DAY. POSSIBLE LIGHT SNOW AROUND
THE EVENING RUSH HOUR IN THE CT RIVER VALLEY. TEMPS SHOULD REACH THE
MID 20S TO AROUND 30.

TUESDAY NIGHT-WEDNESDAY... NORTHERN AND SOUTHERN STREAM SHORTWAVES
MERGE OVER THE GREAT LAKES AND TRACK INTO CANADA. THIS BRINGS A MILD
FLOW OF AIR UP OVER NEW ENGLAND. THE LEADING EDGE OF THIS AIR
REACHES WESTERN SECTIONS TUESDAY EVENING AND EASTERN SECTIONS
TUESDAY NIGHT. TEMPERATURE PROFILES SUPPORT AN INITIAL PERIOD OF
SNOW CHANGING TO RAIN OR FREEZING RAIN OVERNIGHT. ACTUALLY...THE
MODELS MAY NOT BE HANDLING WELL THE CHILLING MASS OF SNOW AND COLD
GROUND /A.K.A. THE GIANT ICECUBE/ WHICH WOULD MEAN THE ACTUAL MAX
SFC TEMPS WILL BE COOLER THAN MODEL FORECASTS. TEMPERATURES AT 925
AND 950 MB WILL BE IN THE 30S...SO EXPECT SURFACE TEMPS NO HIGHER
THAN THE LOWER 40S.

THE SURFACE LOW PRESSURE AREA PASSES WELL NORTH OF NEW ENGLAND
WEDNESDAY AND SWINGS A COLD FRONT THROUGH THE REGION DURING THE
AFTERNOON OR EVENING. MOISTURE CROSS SECTIONS SHOW DECREASING RH IN
THE LIFT AND NUCLEATION ZONES ALOFT WEDNESDAY MORNING...SO THE TREND
THROUGH THE DAY SHOULD BE TO DIMINISHING POPS.

THURSDAY-FRIDAY... THE WEDNESDAY COLD FRONT WILL ALIGN WITH THE
UPPER FLOW AS IT MOVES SOUTH OF NEW ENGLAND...SLOWING ITS OFFSHORE
PROGRESS TO A CRAWL. MEANWHILE WE WILL BE UNDER THE RIGHT ENTRANCE
REGION OF THE SUPPORTING UPPER JET...A SOURCE OF UPPER VENTING. THIS
SHOULD SUPPORT LINGERING CLOUDS AND A CHANCE OF PCPN...WITH TEMPS
SUPPORTIVE OF SNOW. BEST CHANCE SOUTH COAST...LESSER CHANCE FARTHER
NORTH. THE JET AND SURFACE FRONT SWEEP OFFSHORE THURSDAY NIGHT. HIGH
PRESSURE THEN MOVES OVER THE EASTERN USA FOR FRIDAY. TEMPS ALOFT
SUPPORT MAX SFC TEMPS IN THE 20S.

SATURDAY-SUNDAY... ANOTHER NORTHERN STREAM SHORTWAVE AND COLD FRONT
SWINGS THROUGH THE FLOW SATURDAY. CROSS SECTIONS SHOW SOME MOISTURE
ALOFT BUT MOST OF IT IS CONCENTRATED TO OUR NORTH.  ALSO JUST
LIMITED LIFT TO WORK ON THAT MOISTURE. WE WILL HAVE 25-50 PCT SKY
COVER AND NIL POPS. HIGH PRESSURE THEN BUILDS FOR SUNDAY.

&&

.AVIATION /21Z SUNDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TODAY AND TONIGHT/...

18Z UPDATE...MODERATE CONFIDENCE.

THIS AFTERNOON...MVFR CIGS/VSBYS IN LIGHT SNOW AT BAF-BDL BUT MAINLY
VFR TO THE EAST TO START...WITH CIGS AND/OR VSBYS LOWERING TO MVFR
ACROSS THE REMAINDER OF SOUTHERN NEW ENGLAND TERMINALS BETWEEN
18Z AND 21Z IN LIGHT SNOW.

TONIGHT...MODERATE CONFIDENCE. THE BULK OF THE MODERATE TO EVEN
BRIEFLY HEAVY SNOW WILL OCCUR THIS EVENING WHEN WIDESPREAD IFR TO
LIFR CONDITIONS OCCUR. THE LOWEST CONDITIONS WILL MOST LIKELY BE
SOUTH OF THE MA TURNPIKE. PTYPE PRETTY MUCH ALL SNOW...EXCEPT FOR
THE VERY IMMEDIATE SOUTH COAST/CAPE WHERE SNOW MAY MIX WITH OR
CHANGE TO RAIN FOR A TIME. WHETHER OR NOT THAT HAPPENS IS
UNCERTAIN...BUT WE DO THINK THAT AT LEAST THE ISLANDS WILL MIX OR CHANGE
TO RAIN.

BULK OF SNOW ENDS BY 8Z TO 9Z TONIGHT AND MUCH OF THE THE REGION
SHOULD IMPROVE TO VFR CONDITIONS BY 12-13Z MONDAY.

KBOS TAF...CONFIDENT IN OVERALL TRENDS BUT THERE IS UNCERTAINTY ON
TIMING. SOME LIGHT SNOW IS EXPECTED DURING MID TO LATE
AFTERNOON...BUT THE BULK OF ACCUMULATING SNOW WITH IFR TO LIFR
CONDITIONS EXPECTED MAINLY THIS EVENING.

KBDL TAF...CONFIDENT IN OVERALL TRENDS BUT THERE IS UNCERTAINTY ON
TIMING. BULK OF ACCUMULATING SNOW WITH IFR TO LIFR CONDITIONS
EXPECTED AFTER 3 OR 4 PM.

OUTLOOK...TUESDAY THROUGH FRIDAY...

TUESDAY...MODERATE CONFIDENCE. VFR DURING THE DAY WITH INCREASING
SKY COVER. MVFR CIGS/VSBYS POSSIBLE LATE IN THE DAY CT RIVER VALLEY.

TUESDAY NIGHT-WEDNESDAY...MODERATE CONFIDENCE. CONDITIONS LOWERING
TO IFR/LIFR. INITIALLY SNOW BUT CHANGING TO SLEET/FREEZING RAIN
DURING THE NIGHT AND RAIN IN THE COASTAL PLAIN OVERNIGHT. PCPN
CHANGES TO RAIN ALL AREAS WEDNESDAY...BUT COLD SURFACES COULD
MAINTAIN A FREEZING RAIN ELEMENT WEDNESDAY MORNING. COLDER AIR MOVES
IN WEDNESDAY NIGHT CHANGING ANY RAIN TO SNOW.

THURSDAY...LOW CONFIDENCE. VFR NORTH OF A HFD-BOS LINE. MVFR CIGS
AND AREAS OF MVFR/IFR VSBYS IN SNOW...DIMINISHING BY EVENING.
NORTHWEST WINDS GUSTING TO 20 KNOTS.

FRIDAY...MODERATE CONFIDENCE. VFR.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TODAY AND TONIGHT/...HIGH CONFIDENCE.

A WEAK WAVE OF LOW PRESSURE MOVES ACROSS THE WATERS LATER
TODAY AND TONIGHT.  WEAK PRESSURE GRADIENT SHOULD KEEP
WINDS/SEAS BELOW SMALL CRAFT THRESHOLDS TODAY AND TONIGHT.  THE
SYSTEM REALLY INTENSIFIES AS IT MOVES INTO THE CANADIAN MARITIMES
NEAR DAYBREAK MONDAY...SO WESTERLY WIND GUSTS MAY REACH 20 TO 25
KNOTS NEAR 12Z MONDAY.  OTHERWISE...RAIN AND SNOW LATE TODAY AND
ESPECIALLY TONIGHT WILL REDUCE VISIBILITIES AT TIMES FOR MARINERS.

OUTLOOK...TUESDAY THROUGH FRIDAY..MODERATE CONFIDENCE.

TUESDAY... LINGERING 5 FOOT SEAS SOUTH AND EAST OF NANTUCKET IN THE
MORNING BUT DIMINISHING. NORTHWEST WINDS DIMINISHING FROM 20 KNOTS.
ANY SMALL CRAFT ADVISORY SHOULD END IN THE MORNING.

TUESDAY NIGHT-WEDNESDAY...SOUTH TO SOUTHWEST WINDS WILL INCREASE TO
20-25 KNOTS. SEAS WILL BUILD 6 TO 10 FEET ON THE OUTER WATERS AND ON
RI SOUND. REDUCED VSBYS...INITIALLY SNOW BUT CHANGING TO RAIN. A
SMALL CRAFT ADVISORY MAY BE NEEDED.

THURSDAY...NORTHWEST WIND GUSTING TO 25 KNOTS. SEAS 5 TO 8 FEET
MAINLY ON THE OUTER WATERS...DIMINISHING LATE. A SMALL CRAFT
ADVISORY MAY BE NEEDED.

FRIDAY... SHIFTING WINDS LESS THAN 20 KNOTS. SEAS LESS THAN 5 FEET.
QUIET WEATHER.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR CTZ002>004.
MA...WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR MAZ017>021.
     WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR MAZ002>016-
     022>024-026.
RI...WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR RIZ002>008.
     WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR RIZ001.
MARINE...GALE WARNING FROM 11 AM MONDAY TO 4 AM EST TUESDAY FOR ANZ231-
     232-250-251-254-255.
     GALE WARNING FROM 11 AM TO 11 PM EST MONDAY FOR ANZ233>235-237-
     256.
     GALE WARNING FROM 11 AM TO 8 PM EST MONDAY FOR ANZ230-236.

&&

$$
SYNOPSIS...WTB/FRANK
NEAR TERM...FRANK/DOODY/NMB
SHORT TERM...FRANK
LONG TERM...WTB
AVIATION...WTB/FRANK/NMB
MARINE...WTB/FRANK



000
FXUS61 KGYX 011954
AFDGYX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
254 PM EST SUN MAR 1 2015

.SYNOPSIS...
LOW PRESSURE WILL MOVE EAST AND CROSS THE REGION OVERNIGHT...PRODUCING
SOME LIGHT SNOW. A STRONG NORTHWEST FLOW WILL SET UP IN ITS WAKE
ON MONDAY. HIGH PRESSURE WILL BUILD IN FROM THE WEST MONDAY NIGHT
AND WILL CREST OVER THE REGION EARLY TUESDAY BEFORE MOVING
OFFSHORE. LOW PRESSURE WILL SWING THROUGH SOUTHERN CANADA TUESDAY
NIGHT PUSHING A WARM FRONT NORTH ACROSS THE REGION...AND PRODUCING
A PERIOD OF SNOW AND MIXED RAIN OR SNOW ALONG THE COAST. AS THE
LOW SHIFTS TO OUR NORTH...IT WILL DRAG A COLD FRONT THROUGH THE
REGION LATE WEDNESDAY. HIGH PRESSURE WILL BUILD IN FROM THE WEST
THURSDAY AND WILL CREST OVER THE REGION ON FRIDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
SNOW WILL CONTINUE TO SPREAD EAST THIS EVENING IN ASSOCIATION WITH
BROAD SCALE WARM AIR ADVECTION PATTERN. SOME OF THIS PRECIPITATION
HOWEVER WILL CONTINUE TO SUBLIMATE AS IT INTERACTS WITH A VERY
DRY ATMOSPHERE OVER MAINE AND NEW HAMPSHIRE. EXPECT PERIODS OF
LIGHT SNOW OVERNIGHT. 12Z MODEL SUITE AND MESOSCALE MODELS HAVE
CONTINUED TO BACK OFF ON THE PRECIP FIELDS AND THEREFORE SNOWFALL
AMOUNTS. NEVERTHELESS...THE HIGHEST TOTALS WILL BE 3-4 INCHES
ALONG PORTIONS OF THE MIDCOAST AND OVER FAR SOUTHERN NH NEAR THE
MASS BORDER. THIS WILL BE JUST BELOW SNOW ADVISORY CRITERIA.

IT WILL BE A MUCH MILDER NIGHT THAN THOSE OF THE LAST SEVERAL
NIGHTS WITH READINGS BETWEEN 15 AND 25 DEGREES FROM NORTH TO
SOUTH.

&&

.SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
UPPER LEVEL SUPPORT REMAINS DISJOINTED FROM THE SURFACE REFLECTION
ON MONDAY...WITH THE SHORT WAVE CROSSING LAKE ONTARIO BY EARLY
MONDAY MORNING. THERE COULD BE A PASSING SNOW SHOWER WITH THIS
FEATURE. ACROSS THE NORTHWEST FACING HIGHER TERRAIN...SOME
UPSLOPING PRECIPITATION MAY OCCUR.

AS ARCTIC HIGH BUILDS OVER THE REGION...TEMPERATURES WILL ONCE
AGAIN DROP BELOW ZERO IN NORTHERN AREAS. WIND CHILL VALUES WILL BE
HEADING DOWNWARDS AGAIN AS WELL...BRIEFLY APPROACHING WIND CHILL
ADVISORY LEVELS IN THE MOUNTAINS.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
A SUNNY START ON TUESDAY AS HIGH PRESSURE IS CENTERED OVER THE
REGION. INCREASING HIGH CLOUDS WILL SPILL OVER THE SURFACE/UPPER RIDGE
IN THE AFTERNOON AS THE RIDGE AXIS MOVES OFF TO THE EAST. TUESDAY
NIGHT THE SOUTHWEST FLOW ALOFT WILL ALLOW A SHORT WAVE AND
ASSOCIATED WARM FRONT TO MOVE NORTH INTO NORTHERN NEW ENGLAND
WITH WIDESPREAD WARM AIR ADVECTION SNOW EXPECTED. MID/LOW LEVEL
TEMPERATURES SHOULD ALL BE COLD ENOUGH FOR SNOW EXCEPT ALONG THE
IMMEDIATE COAST WHERE A BRIEF MIX WITH RAIN MAY OCCUR BEFORE
ENDING EARLY WEDNESDAY MORNING. A BLEND OF MODELS QPF SUGGESTS A
SNOWFALL OF 2-6 INCHES EXPECTED. ON WEDNESDAY ALL MODELS INDICATE
THE SNOW TO BE OVER BY EARLY MORNING AND THEN SOME CLEARING AND TEMPERATURES
REACHING INTO THE 40S OVER MOST OF THE AREA AS H85 TEMPERATURES
REMAIN MILD INTO THE AFTERNOON COMBINED WITH A DEVELOPING LIGHT
DOWNSLOPING WEST WIND. COLD AIR RETURNS FOR WEDNESDAY NIGHT AND
THURSDAY AS HIGH PRESSURE FROM THE GREAT LAKES BUILDS EAST AND
CONTINUES INTO FRIDAY. TEMPERATURES WILL RETURN TO BELOW NORMAL
FOR THURSDAY AND FRIDAY LIKE A BROKEN RECORD.

&&

.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
SHORT TERM...CEILINGS AND VISIBILITIES GRADUALLY LOWERING AND
DIMINISHING THIS EVENING IN LIGHT SNOW. IFR CONDITIONS EXPECTED IN
MANY AREAS...ESPECIALLY OVER SOUTHERN LOCATIONS.

LONG TERM...
VFR TUESDAY BECOMING IFR TUESDAY NIGHT AND THEN A RETURN TO VFR
CONDITIONS FOR THE MID AND LATTER PART OF THE WEEK.
&&

.MARINE...
SHORT TERM...WILL BE ISSUING GALE WARNINGS FOR MONDAY AFTERNOON
THROUGH MONDAY EVENING FOR THE OUTER WATERS. WINDS WILL JUST TOUCH
GALE FORCE WELL AWAY FROM THE SHORELINE. ALONG THE BAYS...EXPECT
SMALL CRAFT ADVISORY TYPE WINDS INTO TOMORROW EVENING.

LONG TERM...
SCA`S MAY BE NEEDED IN THE SOUTH SOUTHWEST FLOW TUESDAY NIGHT.
THE SCA MAY ALSO BE NEEDED WEDNESDAY NIGHT AND THURSDAY WITH THE
NORTHWEST FLOW.
&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY FROM NOON TO 11 PM EST MONDAY FOR ANZ151-
     153.
     GALE WARNING FROM NOON TO 11 PM EST MONDAY FOR ANZ150-152-154.

&&

$$



000
FXUS61 KGYX 011954
AFDGYX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
254 PM EST SUN MAR 1 2015

.SYNOPSIS...
LOW PRESSURE WILL MOVE EAST AND CROSS THE REGION OVERNIGHT...PRODUCING
SOME LIGHT SNOW. A STRONG NORTHWEST FLOW WILL SET UP IN ITS WAKE
ON MONDAY. HIGH PRESSURE WILL BUILD IN FROM THE WEST MONDAY NIGHT
AND WILL CREST OVER THE REGION EARLY TUESDAY BEFORE MOVING
OFFSHORE. LOW PRESSURE WILL SWING THROUGH SOUTHERN CANADA TUESDAY
NIGHT PUSHING A WARM FRONT NORTH ACROSS THE REGION...AND PRODUCING
A PERIOD OF SNOW AND MIXED RAIN OR SNOW ALONG THE COAST. AS THE
LOW SHIFTS TO OUR NORTH...IT WILL DRAG A COLD FRONT THROUGH THE
REGION LATE WEDNESDAY. HIGH PRESSURE WILL BUILD IN FROM THE WEST
THURSDAY AND WILL CREST OVER THE REGION ON FRIDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
SNOW WILL CONTINUE TO SPREAD EAST THIS EVENING IN ASSOCIATION WITH
BROAD SCALE WARM AIR ADVECTION PATTERN. SOME OF THIS PRECIPITATION
HOWEVER WILL CONTINUE TO SUBLIMATE AS IT INTERACTS WITH A VERY
DRY ATMOSPHERE OVER MAINE AND NEW HAMPSHIRE. EXPECT PERIODS OF
LIGHT SNOW OVERNIGHT. 12Z MODEL SUITE AND MESOSCALE MODELS HAVE
CONTINUED TO BACK OFF ON THE PRECIP FIELDS AND THEREFORE SNOWFALL
AMOUNTS. NEVERTHELESS...THE HIGHEST TOTALS WILL BE 3-4 INCHES
ALONG PORTIONS OF THE MIDCOAST AND OVER FAR SOUTHERN NH NEAR THE
MASS BORDER. THIS WILL BE JUST BELOW SNOW ADVISORY CRITERIA.

IT WILL BE A MUCH MILDER NIGHT THAN THOSE OF THE LAST SEVERAL
NIGHTS WITH READINGS BETWEEN 15 AND 25 DEGREES FROM NORTH TO
SOUTH.

&&

.SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
UPPER LEVEL SUPPORT REMAINS DISJOINTED FROM THE SURFACE REFLECTION
ON MONDAY...WITH THE SHORT WAVE CROSSING LAKE ONTARIO BY EARLY
MONDAY MORNING. THERE COULD BE A PASSING SNOW SHOWER WITH THIS
FEATURE. ACROSS THE NORTHWEST FACING HIGHER TERRAIN...SOME
UPSLOPING PRECIPITATION MAY OCCUR.

AS ARCTIC HIGH BUILDS OVER THE REGION...TEMPERATURES WILL ONCE
AGAIN DROP BELOW ZERO IN NORTHERN AREAS. WIND CHILL VALUES WILL BE
HEADING DOWNWARDS AGAIN AS WELL...BRIEFLY APPROACHING WIND CHILL
ADVISORY LEVELS IN THE MOUNTAINS.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
A SUNNY START ON TUESDAY AS HIGH PRESSURE IS CENTERED OVER THE
REGION. INCREASING HIGH CLOUDS WILL SPILL OVER THE SURFACE/UPPER RIDGE
IN THE AFTERNOON AS THE RIDGE AXIS MOVES OFF TO THE EAST. TUESDAY
NIGHT THE SOUTHWEST FLOW ALOFT WILL ALLOW A SHORT WAVE AND
ASSOCIATED WARM FRONT TO MOVE NORTH INTO NORTHERN NEW ENGLAND
WITH WIDESPREAD WARM AIR ADVECTION SNOW EXPECTED. MID/LOW LEVEL
TEMPERATURES SHOULD ALL BE COLD ENOUGH FOR SNOW EXCEPT ALONG THE
IMMEDIATE COAST WHERE A BRIEF MIX WITH RAIN MAY OCCUR BEFORE
ENDING EARLY WEDNESDAY MORNING. A BLEND OF MODELS QPF SUGGESTS A
SNOWFALL OF 2-6 INCHES EXPECTED. ON WEDNESDAY ALL MODELS INDICATE
THE SNOW TO BE OVER BY EARLY MORNING AND THEN SOME CLEARING AND TEMPERATURES
REACHING INTO THE 40S OVER MOST OF THE AREA AS H85 TEMPERATURES
REMAIN MILD INTO THE AFTERNOON COMBINED WITH A DEVELOPING LIGHT
DOWNSLOPING WEST WIND. COLD AIR RETURNS FOR WEDNESDAY NIGHT AND
THURSDAY AS HIGH PRESSURE FROM THE GREAT LAKES BUILDS EAST AND
CONTINUES INTO FRIDAY. TEMPERATURES WILL RETURN TO BELOW NORMAL
FOR THURSDAY AND FRIDAY LIKE A BROKEN RECORD.

&&

.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
SHORT TERM...CEILINGS AND VISIBILITIES GRADUALLY LOWERING AND
DIMINISHING THIS EVENING IN LIGHT SNOW. IFR CONDITIONS EXPECTED IN
MANY AREAS...ESPECIALLY OVER SOUTHERN LOCATIONS.

LONG TERM...
VFR TUESDAY BECOMING IFR TUESDAY NIGHT AND THEN A RETURN TO VFR
CONDITIONS FOR THE MID AND LATTER PART OF THE WEEK.
&&

.MARINE...
SHORT TERM...WILL BE ISSUING GALE WARNINGS FOR MONDAY AFTERNOON
THROUGH MONDAY EVENING FOR THE OUTER WATERS. WINDS WILL JUST TOUCH
GALE FORCE WELL AWAY FROM THE SHORELINE. ALONG THE BAYS...EXPECT
SMALL CRAFT ADVISORY TYPE WINDS INTO TOMORROW EVENING.

LONG TERM...
SCA`S MAY BE NEEDED IN THE SOUTH SOUTHWEST FLOW TUESDAY NIGHT.
THE SCA MAY ALSO BE NEEDED WEDNESDAY NIGHT AND THURSDAY WITH THE
NORTHWEST FLOW.
&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY FROM NOON TO 11 PM EST MONDAY FOR ANZ151-
     153.
     GALE WARNING FROM NOON TO 11 PM EST MONDAY FOR ANZ150-152-154.

&&

$$




000
FXUS61 KBOX 011810
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
110 PM EST SUN MAR 1 2015

.SYNOPSIS...
A FAST MOVING LOW PRESSURE SYSTEM WILL BRING ACCUMULATING SNOW
LATER TODAY AND ESPECIALLY TONIGHT WITH THE HIGHEST AMOUNTS
EXPECTED SOUTH OF THE MASSACHUSETTS TURNPIKE. HIGH PRESSURE
BRINGS DRY COLD AIR FOR THE EARLY WEEK. LOW PRESSURE FROM NORTHERN
CANADA AND ASSOCIATED LOW FORMING OVER THE PLAINS MONDAY WILL
MERGE...THEN PASS WEST AND NORTH OF NEW ENGLAND. THIS WILL SWING A
COLD FRONT ACROSS THE REGION ON WEDNESDAY. DRY AND COLD WEATHER
RETURNS FOR THE END OF THE WEEK.

&&

.NEAR TERM /UNTIL 5 PM THIS AFTERNOON/...
1 PM UPDATE...

LIGHT SNOW IS WORKING ITS WAY INTO SOUTHERN NEW ENGLAND...BASED ON
18Z OBS LIGHT SNOW HAS MADE IT INTO THE SPRINGFIELD AREA AND LIGHT
SNOW HAS EVEN STARTED AT PVD. THE SNOW WILL CONTINUE TO GRADUALLY
OVERSPREAD THE REMAINDER OF OUR AREA AS THE AFTERNOON
PROGRESSES...LIKELY REACHING BOSTON AROUND 20Z. AGAIN ONLY MINOR CHANGES
MADE TO HOURLY TEMPS TO REFLECT LATEST OBS...FORECAST HIGHS
CONTINUE TO LOOK ON TRACK.

EARLY MORNING DISCUSSION...

MID LEVEL CLOUDINESS WILL STREAM INTO SOUTHERN NEW ENGLAND AND
THICKEN DURING THE MORNING HOURS IN ADVANCE OF APPROACHING LOW
PRESSURE.  SOUTHWEST FLOW ALOFT OVERRUNING THE COLD DOME AT THE
SURFACE MAY ALLOW FOR SOME LIGHT SNOW/FLURRIES TO BREAK
OUT ACROSS THE INTERIOR LATE THIS MORNING/EARLY AFTERNOON AND THEN
FIND THEIR WAY TO THE COAST BY MID TO LATE AFTERNOON.  THE LIFT
THROUGH MID AFTERNOON IS FAIRLY WEAK...SO THE AREAS OF SNOW SHOULD
BE RATHER LIGHT. ANY ACCUMULATIONS THAT OCCUR WILL PROBABLY BE
A DUSTING TO LESS THAN 1 INCH THROUGH THAT THAT TIME.  HIGH TEMPS
WILL MAINLY BE IN THE UPPER 20S TO AROUND 30.

&&

.SHORT TERM /5 PM THIS AFTERNOON THROUGH 6 AM MONDAY/...
*** BULK OF THE ACCUMULATING SNOW OCCURS BETWEEN 3 PM AND 1 AM WITH
  THE HEAVIEST AMOUNTS SOUTH OF THE MA TURNPIKE ***

1) OVERVIEW AND TIMING:

THE BULK OF THE ACCUMULATING SNOW WILL OCCUR BETWEEN 3 PM AND
1 AM ACROSS THE REGION.  THE SNOW SHOULD TAPER OFF TO FLURRIES
TOWARD DAYBREAK MONDAY.  THE MODELS DO AGREE THAT THE BETTER FORCING
WILL OCCUR TO THE SOUTH OF THE MA TURNPIKE.  THIS A RESULT
OF SECONDARY LOW PRESSURE NEAR THE SOUTH COAST...ALLOWING FOR
SOME SURFACE CONVERGENCE AS WELL AS THE INTENSIFICATION OF THE LOW
LEVEL JET.

THE BIGGEST ISSUE IS THE MODELS ARE NOT IN AGREEMENT IN HOW
INTENSE THE FORCING WILL BE ACROSS THE REGION THIS EVENING.  THE
RGEM/NAM ARE THE MOST ROBUST WITH QPF SOUTH OF THE MA TURNPIKE.  THE
NAM SHOWS A PERIOD OF FAIRLY STRONG LIFT OF 15 TO 20 MICROBARS PER
SECOND WITHIN THE BEST SNOWGROWTH REGION THIS EVENING.  THIS WOULD
TRANSLATE TO A PERIOD OF 1+ INCH PER HOUR SNOWFALL RATES NEAR AND
SOUTH OF THE MA PIKE.  ON THE OTHER HAND...THE GFS ALSO HAS FAIRLY
STRONG LIFT...BUT KEEPS IT SOUTHEAST OF OUR REGION OUT OVER THE
OCEAN.  THE SECONDARY LOW PRESSURE SYSTEM ON THE GFS IS WEAKER AND
FURTHER SOUTHEAST...RESULTING IN THE LOW LEVEL JET BEING DISPLACED
FURTHER EAST.  THE ECMWF/UKMET SOLUTIONS SEEM TO BE THE MIDDLE
GROUND WHICH WE WILL LEAN TOWARDS.

2) WINTER WEATHER HEADLINES AND SNOW ACCUMS:

WITH THAT SAID...THE OTHER DILEMMA IS WHAT TO DO WITH THE CURRENT
HEADLINES.  THIS DOES NOT APPEAR TO BE THE TYPE OF SETUP WHERE WE
ARE GOING TO RECEIVE WIDESPREAD WARNING SNOWFALL AMOUNTS.  THE
WINDOW FOR THE VERY STRONG LIFT/FORCING IS SHORT-LIVED AND REALLY
WOULD LIKE TO SEE THE LOW LEVEL JET A BIT MORE BACKED TO TRANSPORT
DEEPER MOISTURE NORTHWARD.  THEREFORE...FEEL THAT FOR MOST OF THE
REGION WINTER WEATHER ADVISORY/S FOR 3 TO 6 INCHES OF SNOW WILL
COVER IT.  HOWEVER...GIVEN THERE IS NICE OMEGA IN THE SNOW GROWTH
REGION...WE MIGHT BE LOOKING AT SOME DECENT RATIOS.  SO WE STILL CAN
NOT RULE OUT THE LOW RISK OF REACHING WARNING AMOUNTS AND LATER
SHIFTS WILL HAVE TO MONITOR CLOSELY...ESPECIALLY ACROSS NORTHERN CT
AND NORTHWEST RI.

WE DID UPGRADE A SMALL AREA FROM CENTRAL AND SOUTHERN RHODE ISLAND
INTO SOUTHEAST MA INCLUDING THE SOUTH COAST TO A WINTER
STORM WARNING.  THE NOSE OF THE LOW LEVEL JET LOOKS TO TRANSPORT
SOME DEEPER MOISTURE INTO THIS REGION.  THERE ALSO COULD BE SOME
ENHANCEMENT ALONG THE LAND/SEA INTERFACE AND A WEAK SURFACE
BOUNDARY SO WENT WITH 4 TO 8 INCHES IN THIS REGION.

3) PTYPE AND IMPACTS:

THE MODELS HAVE TRENDED COLDER OVER THE PAST 24 HOURS.
THEREFORE...EXPECT THIS BE PRETTY MUCH A SNOW EVENT.  IT DOES BECOME
A VERY CLOSE CALL NEAR THE SOUTH COAST...BUT WERE LEANING TOWARDS IT
STAYING MAINLY WET SNOW.  IF PRECIPITATION LIGHTENS UP THAT MAY
INCREASE THIS RISK WE SEE A BRIEF CHANGE OVER TO RAIN.
MEANWHILE...WE WENT WITH A HIGH END WINTER WEATHER ADVISORY FOR THE
CAPE BECAUSE THEY MAY CHANGE TO RAIN FOR A TIME...ESPECIALLY EAST OF
HYANNIS.  IF THE CHANGE OVER DOES NOT OCCUR...WE MAY NEED TO UPGRADE
THEM TO A WINTER STORM WARNING ESPECIALLY NEAR THE CAPE COD CANAL
GIVEN EXPECTED QPF.

THE ONE THING WILL ALSO HAVE TO WATCH IS AREAS NEAR THE SOUTH COAST
AND CAPE COD.  LOOKS TO BE A WET SNOW DOWN THAT WAY AND ON GOING
ROOF ISSUES MAY BE EXACERBATED...ESPECIALLY IF ANY AREAS THAT ARE
ABLE TO EXCEED 6 INCHES OF WET SNOW.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
HIGHLIGHTS...

  * BLUSTERY CONDITIONS ON MON WITH DRY WEATHER CONTINUING INTO
    TUE.
  * A STORM SYSTEM BRINGS MIXED PRECIP TUE INTO WED.
  * CONDITIONS IMPROVE THU BUT BECOMING COLD AGAIN.

OVERVIEW AND MODEL PREFERENCES...
A SPLIT FLOW MERGER WILL BE THE DEFINING FACTOR THROUGH THE LONG
TERM FORECAST PERIOD. IN THE MID TERM...THE STREAMS MERGE THANKS
TO PHASING OF NRN AND SRN STREAM SHORTWAVES UPSTREAM AS MERGING
STRONG JET DEVELOPS ACROSS THE NE CONUS. THESE FEATURES WILL ALLOW
LOW PRES TO GRADUALLY DEEPEN AND SLIDE THROUGH SRN ONTARIO AND
QUEBEC...CREATING AN OVERRUNNING EVENT AS THE SYSTEM ATTEMPTS TO
OCCLUDE. THIS IS THE MIXED PRECIP EVENT WE HAVE BEEN DISCUSSING
FOR SOME TIME NOW. NOW THAT NAM HAS CAPTURED IT...IT APPEARS
COLDER THAN MOST OF THE DETERMINISTIC GUIDANCE...WHILE THE ECMWF
STARTS COLD AND SHIFTS TO THE WARMER SIDE OF THE ENVELOPE DUE TO
THE FACT THAT IT IS MORE AMPLIFIED THAN OTHER MODELS. THE
GFS...ECENS/GEFS MEANS ARE ACTUALLY A GOOD MIDDLE GROUND HERE.
THIS BLEND WILL BE USED THROUGH THE REMAINDER OF THE LONG TERM AS
WELL TO TAKE INTO ACCOUNT THE VARIOUS SOLUTIONS.

DETAILS...

MON INTO TUE...
REMNANT SNOWFALLS WILL BE GRADUALLY COMING TO AN END THROUGH MID
MORNING MON...ALTHOUGH FLURRIES MAY LINGER A BIT LONGER IN THE
BERKSHIRES. STRONG HIGH PRES WILL THEN SLIDE ACROSS THE REGION
THROUGH TUE...WITH MAINLY DRY WX. TEMPS LOOK TO REMAIN BELOW
NORMAL GIVEN LITTLE CHANGE IN THE AIRMASS FROM PREVIOUS DAYS.

TUE NIGHT INTO WED...
OVERRUNNING EVENT EXPECTED AS WARM FRONT WILL ATTEMPT TO PUSH N
ACROSS THE REGION BUT IS LIKELY TO STRUGGLE NEAR THE SFC DUE TO
ENTRENCHED COLD AIR AND A DEEP SNOWPACK. HOWEVER...50-60 KT LLJ
WITH STRONG SLY COMPONENT WILL ALLOW UPPER LVL WARMING TON
CONTINUE UNIMPEDED. IN SPITE OF THE STRONG JET AT ONLY 3-5KFT
ABOVE THE SFC...SNOWPACK WILL MAKE MIXING DIFFICULT SO NOT
EXPECTING SIGNIFICANT WIND ISSUES AT THIS TIME.

THE COLUMN STARTS COLD ENOUGH FOR SNOW AT ONSET TUE EVENING...AND
LOOKS LIKE AS MUCH AS 0.40-0.60 OF THE TOTAL EVENT QPF FALLS AS
SNOW INITIALLY EVERYWHERE...WITH GRADUAL CHANGEOVER DURING THE
EARLY MORNING HOURS WED MORNING FROM S-N. THEREFORE...COULD SEE AT
LEAST ADVISORY IF NOT LOW-END WARNING LVL SNOWFALLS THROUGH THE
OVERNIGHT HOURS BEFORE A TRANSITION TO SLEET...THEN FREEZING RAIN.
FREEZING RAIN COULD LOCK IN FOR SOME TIME AND GIVEN THAT H93 TEMPS
/EVEN ON THE COLDEST GUIDANCE/ AN AVERAGE OF +4C DURING THE 08Z-
16Z TIMEFRAME...BUT SFC TEMPS MAY HOLD NEAR FREEZING FOR SOME TIME
GIVEN THE DEEP SNOWPACK ACROSS THE AREA. HOWEVER...STRAIGHT RAIN
FOR A TIME FROM ABOUT MID MORNING INTO THE AFTERNOON IS LIKELY
UNTIL THE PRECIP COMES TO AN END. DEPENDING ON HOW QUICKLY 2M
TEMPS REBOUND...AS MUCH AS A QUARTER INCH OF ICE CAN/T BE RULED
OUT. AGREE WITH PREVIOUS FORECASTER THAT LEANING A BIT COLDER THAN
MOS 2M TEMPS IS PROBABLY THE WAY TO GO.

MODEST UPPER LVL INSTABILITY AS WARMING OCCURS IN THE MID LVLS
COULD ALSO MEAN A PERIOD OF HEAVY PRECIP...BOTH SNOW AND RAIN.
WITH THE RAIN...COMES A RISK FOR POOR DRAINAGE FLOODING ACROSS THE
REGION AS SNOW MELTS AND DRAINS BECOME CLOGGED. PRECIP COMES TO AN
END ACROSS MOST OF THE REGION BY AFTERNOON WED...BUT MAY LINGER A
BIT NEAR THE S COAST...MORE ON THAT BELOW.

WED NIGHT INTO THU...
CONFIDENCE IN THE FORECAST CONTINUES TO DIMINISH HERE PARTIALLY
DEPENDENT ON HOW FAST THE UPPER LVL JET EXITS TO THE EAST AND HOW
AMPLIFIED THE PATTERN REMAINS IN THE WAKE OF THE LOW PRES. THE
MORE AMPLIFIED GUIDANCE...LED BY THE ECMWF KEEPS THE COLD FRONT
JUST OFFSHORE AND WITHIN THE EQUATORWARD ENTRANCE REGION OF THE
UPPER LVL JET. THIS SUGGESTS S COASTAL AREAS COULD CONTINUE TO SEE
PRECIP...POSSIBLY EVEN CHANGING BACK TO SNOW FOR A TIME WELL INTO
THE DAY ON THU. THE MORE PROGRESSIVE GUIDANCE...LED BY THE GFS
WOULD MOVE BOTH OF THESE FEATURES OFFSHORE SUCH THAT THU IS
MAINLY DRY AND BECOMING QUITE COLD AS ANOTHER ARCTIC AIRMASS
SETTLES IN. FOR NOW...WILL CONTINUE TO LEAN ON THE MORE
PROGRESSIVE GFS BUT WITH THE ECENS/GEFS SLOWER MEMBERS BLENDED IN.
THE FINAL ANSWER WILL LIKELY BE SOMEWHERE IN BETWEEN THE TWO
SOLUTIONS. IN ANY CASE...MUCH COLDER AIRMASS EXPECTED TO MOVE IN.

THU NIGHT INTO FRI NIGHT...
COLD AIRMASS ACROSS THE REGION ASSOCIATED WITH YET ANOTHER 1035+
HPA HIGH PRES. WILL LIKELY SEE HIGHS ONLY MAKING THE TEENS AND 20S
WITH LOWS BACK IN THE SINGLE DIGITS ABOVE AND BELOW ZERO.

NEXT WEEKEND...
SOME UNCERTAINTY HERE AS TO WHETHER YET ANOTHER WAVE WILL BE
EFFECT THE REGION. WILL LEAN MAINLY DRY FOR NOW AS THE AIRMASS IN
PLACE IS QUITE DRY AND THE WAVE ITSELF IS QUITE WEAK AND SHEARING
OUT.

&&

.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TODAY AND TONIGHT/...

18Z UPDATE...MODERATE CONFIDENCE.

THIS AFTERNOON...MVFR CIGS/VSBYS IN LIGHT SNOW AT BAF-BDL BUT MAINLY
VFR TO THE EAST TO START...WITH CIGS AND/OR VSBYS LOWERING TO MVFR
ACROSS THE REMAINDER OF SOUTHERN NEW ENGLAND TERMINALS BETWEEN
18Z AND 21Z IN LIGHT SNOW.

TONIGHT...MODERATE CONFIDENCE. THE BULK OF THE MODERATE TO EVEN
BRIEFLY HEAVY SNOW WILL OCCUR THIS EVENING WHEN WIDESPREAD IFR TO
LIFR CONDITIONS OCCUR. THE LOWEST CONDITIONS WILL MOST LIKELY BE
SOUTH OF THE MA TURNPIKE. PTYPE PRETTY MUCH ALL SNOW...EXCEPT FOR
THE VERY IMMEDIATE SOUTH COAST/CAPE WHERE SNOW MAY MIX WITH OR
CHANGE TO RAIN FOR A TIME. WHETHER OR NOT THAT HAPPENS IS
UNCERTAIN...BUT WE DO THINK THAT AT LEAST THE ISLANDS WILL MIX OR CHANGE
TO RAIN.

BULK OF SNOW ENDS BY 8Z TO 9Z TONIGHT AND MUCH OF THE THE REGION
SHOULD IMPROVE TO VFR CONDITIONS BY 12-13Z MONDAY.

KBOS TAF...CONFIDENT IN OVERALL TRENDS BUT THERE IS UNCERTAINTY ON
TIMING. SOME LIGHT SNOW IS EXPECTED DURING MID TO LATE
AFTERNOON...BUT THE BULK OF ACCUMULATING SNOW WITH IFR TO LIFR
CONDITIONS EXPECTED MAINLY THIS EVENING.

KBDL TAF...CONFIDENT IN OVERALL TRENDS BUT THERE IS UNCERTAINTY ON
TIMING. BULK OF ACCUMULATING SNOW WITH IFR TO LIFR CONDITIONS
EXPECTED AFTER 3 OR 4 PM.

OUTLOOK...MONDAY THROUGH THURSDAY...

MONDAY...HIGH CONFIDENCE.
IFR/MVFR IN REMNANT SNOWS END EARLY...WITH TRANSITION TO VFR
EVERYWHERE BY AFTERNOON. W-NW WIND GUSTS UP TO AROUND 30 KT AT
TIMES DURING THE AFTERNOON AND EVENING.

MON NIGHT INTO TUE...HIGH CONFIDENCE.
MAINLY VFR. WINDS DIMINISH MON NIGHT.

TUE NIGHT INTO THU...MODERATE CONFIDENCE.
A MESSY PERIOD. SNOW BEGINS EVERYWHERE LATE TUE INTO WED NIGHT
WITH MODERATE ACCUMS POSSIBLE...THEN EXPECT GRADUALLY TRANSITION
TO SLEET AND FREEZING RAIN DURING THE EARLY MORNING HOURS
WED...THEN TO ALL RAIN DURING THE DAY ON WED. SOME ICE ACCUM
POSSIBLE AS WELL. THE RAIN DIMINISHES LATE WED BUT MAY LINGER
ALONG THE S COAST AND EVEN CHANGE TO SNOW INTO THE DAY ON THU.
EXPECT PERIODS OF IFR/LIFR CONDITIONS THROUGHOUT THE PERIOD WITH
SOME IMPROVEMENT FROM N-S ON THU. LLWS LIKELY ESPECIALLY TUE NIGHT
AND EARLY WED.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TODAY AND TONIGHT/...HIGH CONFIDENCE.

A WEAK WAVE OF LOW PRESSURE MOVES ACROSS THE WATERS LATER
TODAY AND TONIGHT.  WEAK PRESSURE GRADIENT SHOULD KEEP
WINDS/SEAS BELOW SMALL CRAFT THRESHOLDS TODAY AND TONIGHT.  THE
SYSTEM REALLY INTENSIFIES AS IT MOVES INTO THE CANADIAN MARITIMES
NEAR DAYBREAK MONDAY...SO WESTERLY WIND GUSTS MAY REACH 20 TO 25
KNOTS NEAR 12Z MONDAY.  OTHERWISE...RAIN AND SNOW LATE TODAY AND
ESPECIALLY TONIGHT WILL REDUCE VISIBILITIES AT TIMES FOR MARINERS.

OUTLOOK...MONDAY THROUGH THURSDAY..MODERATE CONFIDENCE.

MONDAY INTO MONDAY NIGHT...HIGH CONFIDENCE.
WINDS BEGIN OUT OF THE SW THEN SHIFT TO W-NW IN THE AFTERNOON.
WIND GUSTS REACH 35-40 KT DURING THE AFTERNOON AND OVERNIGHT SO
WILL BE ISSUING A GALE WATCH. SEAS BUILD 10-12 FT ON THE OCEAN
WATERS. SOME LIGHT FREEZING SPRAY POSSIBLE MON EVENING INTO TUE
MORNING.

TUE...HIGH CONFIDENCE.
WINDS AND SEAS START AT OR AROUND SMALL CRAFT ADVISORY THRESHOLDS
BUT THEN DROP DURING THE DAY SUCH THAT A PERIOD OF QUIET BOATING
WEATHER IS LIKELY TUE AFTERNOON AND EVENING.

TUE NIGHT INTO THU...MODERATE CONFIDENCE.
LOW PRES PASSES WELL INLAND...WITH WINDS OUT OF THE S GRADUALLY
SHIFTING TO THE W LATE WED INTO THU. PERIODS OF WIND GUSTS 25-30
KT EXPECTED ALTHOUGH GUSTS MAY APPROACH GALE FORCE WED EVENING.
SEAS BUILD THROUGH WED TO AROUND 7-10FT ON THE OCEAN WATERS THEN
DIMINISH THU. AT THE VERY LEAST SMALL CRAFT ADVISORIES ARE LIKELY
DURING THIS PERIOD. PERIODS OF SNOW CHANGING TO RAIN EARLY WED
WITH SOME LOW VSBYS IN RAIN AND FOG ON WED.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR CTZ002>004.
MA...WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR MAZ002>016-
     022>024-026.
     WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR MAZ017>021.
RI...WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR RIZ001-008.
     WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR RIZ002>007.
MARINE...GALE WATCH FROM MONDAY MORNING THROUGH LATE MONDAY NIGHT FOR
     ANZ231>235-237-250-251-254>256.

&&

$$
SYNOPSIS...FRANK/DOODY
NEAR TERM...FRANK/DOODY/NMB
SHORT TERM...FRANK
LONG TERM...DOODY
AVIATION...FRANK/DOODY/NMB
MARINE...FRANK/DOODY



000
FXUS61 KBOX 011810
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
110 PM EST SUN MAR 1 2015

.SYNOPSIS...
A FAST MOVING LOW PRESSURE SYSTEM WILL BRING ACCUMULATING SNOW
LATER TODAY AND ESPECIALLY TONIGHT WITH THE HIGHEST AMOUNTS
EXPECTED SOUTH OF THE MASSACHUSETTS TURNPIKE. HIGH PRESSURE
BRINGS DRY COLD AIR FOR THE EARLY WEEK. LOW PRESSURE FROM NORTHERN
CANADA AND ASSOCIATED LOW FORMING OVER THE PLAINS MONDAY WILL
MERGE...THEN PASS WEST AND NORTH OF NEW ENGLAND. THIS WILL SWING A
COLD FRONT ACROSS THE REGION ON WEDNESDAY. DRY AND COLD WEATHER
RETURNS FOR THE END OF THE WEEK.

&&

.NEAR TERM /UNTIL 5 PM THIS AFTERNOON/...
1 PM UPDATE...

LIGHT SNOW IS WORKING ITS WAY INTO SOUTHERN NEW ENGLAND...BASED ON
18Z OBS LIGHT SNOW HAS MADE IT INTO THE SPRINGFIELD AREA AND LIGHT
SNOW HAS EVEN STARTED AT PVD. THE SNOW WILL CONTINUE TO GRADUALLY
OVERSPREAD THE REMAINDER OF OUR AREA AS THE AFTERNOON
PROGRESSES...LIKELY REACHING BOSTON AROUND 20Z. AGAIN ONLY MINOR CHANGES
MADE TO HOURLY TEMPS TO REFLECT LATEST OBS...FORECAST HIGHS
CONTINUE TO LOOK ON TRACK.

EARLY MORNING DISCUSSION...

MID LEVEL CLOUDINESS WILL STREAM INTO SOUTHERN NEW ENGLAND AND
THICKEN DURING THE MORNING HOURS IN ADVANCE OF APPROACHING LOW
PRESSURE.  SOUTHWEST FLOW ALOFT OVERRUNING THE COLD DOME AT THE
SURFACE MAY ALLOW FOR SOME LIGHT SNOW/FLURRIES TO BREAK
OUT ACROSS THE INTERIOR LATE THIS MORNING/EARLY AFTERNOON AND THEN
FIND THEIR WAY TO THE COAST BY MID TO LATE AFTERNOON.  THE LIFT
THROUGH MID AFTERNOON IS FAIRLY WEAK...SO THE AREAS OF SNOW SHOULD
BE RATHER LIGHT. ANY ACCUMULATIONS THAT OCCUR WILL PROBABLY BE
A DUSTING TO LESS THAN 1 INCH THROUGH THAT THAT TIME.  HIGH TEMPS
WILL MAINLY BE IN THE UPPER 20S TO AROUND 30.

&&

.SHORT TERM /5 PM THIS AFTERNOON THROUGH 6 AM MONDAY/...
*** BULK OF THE ACCUMULATING SNOW OCCURS BETWEEN 3 PM AND 1 AM WITH
  THE HEAVIEST AMOUNTS SOUTH OF THE MA TURNPIKE ***

1) OVERVIEW AND TIMING:

THE BULK OF THE ACCUMULATING SNOW WILL OCCUR BETWEEN 3 PM AND
1 AM ACROSS THE REGION.  THE SNOW SHOULD TAPER OFF TO FLURRIES
TOWARD DAYBREAK MONDAY.  THE MODELS DO AGREE THAT THE BETTER FORCING
WILL OCCUR TO THE SOUTH OF THE MA TURNPIKE.  THIS A RESULT
OF SECONDARY LOW PRESSURE NEAR THE SOUTH COAST...ALLOWING FOR
SOME SURFACE CONVERGENCE AS WELL AS THE INTENSIFICATION OF THE LOW
LEVEL JET.

THE BIGGEST ISSUE IS THE MODELS ARE NOT IN AGREEMENT IN HOW
INTENSE THE FORCING WILL BE ACROSS THE REGION THIS EVENING.  THE
RGEM/NAM ARE THE MOST ROBUST WITH QPF SOUTH OF THE MA TURNPIKE.  THE
NAM SHOWS A PERIOD OF FAIRLY STRONG LIFT OF 15 TO 20 MICROBARS PER
SECOND WITHIN THE BEST SNOWGROWTH REGION THIS EVENING.  THIS WOULD
TRANSLATE TO A PERIOD OF 1+ INCH PER HOUR SNOWFALL RATES NEAR AND
SOUTH OF THE MA PIKE.  ON THE OTHER HAND...THE GFS ALSO HAS FAIRLY
STRONG LIFT...BUT KEEPS IT SOUTHEAST OF OUR REGION OUT OVER THE
OCEAN.  THE SECONDARY LOW PRESSURE SYSTEM ON THE GFS IS WEAKER AND
FURTHER SOUTHEAST...RESULTING IN THE LOW LEVEL JET BEING DISPLACED
FURTHER EAST.  THE ECMWF/UKMET SOLUTIONS SEEM TO BE THE MIDDLE
GROUND WHICH WE WILL LEAN TOWARDS.

2) WINTER WEATHER HEADLINES AND SNOW ACCUMS:

WITH THAT SAID...THE OTHER DILEMMA IS WHAT TO DO WITH THE CURRENT
HEADLINES.  THIS DOES NOT APPEAR TO BE THE TYPE OF SETUP WHERE WE
ARE GOING TO RECEIVE WIDESPREAD WARNING SNOWFALL AMOUNTS.  THE
WINDOW FOR THE VERY STRONG LIFT/FORCING IS SHORT-LIVED AND REALLY
WOULD LIKE TO SEE THE LOW LEVEL JET A BIT MORE BACKED TO TRANSPORT
DEEPER MOISTURE NORTHWARD.  THEREFORE...FEEL THAT FOR MOST OF THE
REGION WINTER WEATHER ADVISORY/S FOR 3 TO 6 INCHES OF SNOW WILL
COVER IT.  HOWEVER...GIVEN THERE IS NICE OMEGA IN THE SNOW GROWTH
REGION...WE MIGHT BE LOOKING AT SOME DECENT RATIOS.  SO WE STILL CAN
NOT RULE OUT THE LOW RISK OF REACHING WARNING AMOUNTS AND LATER
SHIFTS WILL HAVE TO MONITOR CLOSELY...ESPECIALLY ACROSS NORTHERN CT
AND NORTHWEST RI.

WE DID UPGRADE A SMALL AREA FROM CENTRAL AND SOUTHERN RHODE ISLAND
INTO SOUTHEAST MA INCLUDING THE SOUTH COAST TO A WINTER
STORM WARNING.  THE NOSE OF THE LOW LEVEL JET LOOKS TO TRANSPORT
SOME DEEPER MOISTURE INTO THIS REGION.  THERE ALSO COULD BE SOME
ENHANCEMENT ALONG THE LAND/SEA INTERFACE AND A WEAK SURFACE
BOUNDARY SO WENT WITH 4 TO 8 INCHES IN THIS REGION.

3) PTYPE AND IMPACTS:

THE MODELS HAVE TRENDED COLDER OVER THE PAST 24 HOURS.
THEREFORE...EXPECT THIS BE PRETTY MUCH A SNOW EVENT.  IT DOES BECOME
A VERY CLOSE CALL NEAR THE SOUTH COAST...BUT WERE LEANING TOWARDS IT
STAYING MAINLY WET SNOW.  IF PRECIPITATION LIGHTENS UP THAT MAY
INCREASE THIS RISK WE SEE A BRIEF CHANGE OVER TO RAIN.
MEANWHILE...WE WENT WITH A HIGH END WINTER WEATHER ADVISORY FOR THE
CAPE BECAUSE THEY MAY CHANGE TO RAIN FOR A TIME...ESPECIALLY EAST OF
HYANNIS.  IF THE CHANGE OVER DOES NOT OCCUR...WE MAY NEED TO UPGRADE
THEM TO A WINTER STORM WARNING ESPECIALLY NEAR THE CAPE COD CANAL
GIVEN EXPECTED QPF.

THE ONE THING WILL ALSO HAVE TO WATCH IS AREAS NEAR THE SOUTH COAST
AND CAPE COD.  LOOKS TO BE A WET SNOW DOWN THAT WAY AND ON GOING
ROOF ISSUES MAY BE EXACERBATED...ESPECIALLY IF ANY AREAS THAT ARE
ABLE TO EXCEED 6 INCHES OF WET SNOW.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
HIGHLIGHTS...

  * BLUSTERY CONDITIONS ON MON WITH DRY WEATHER CONTINUING INTO
    TUE.
  * A STORM SYSTEM BRINGS MIXED PRECIP TUE INTO WED.
  * CONDITIONS IMPROVE THU BUT BECOMING COLD AGAIN.

OVERVIEW AND MODEL PREFERENCES...
A SPLIT FLOW MERGER WILL BE THE DEFINING FACTOR THROUGH THE LONG
TERM FORECAST PERIOD. IN THE MID TERM...THE STREAMS MERGE THANKS
TO PHASING OF NRN AND SRN STREAM SHORTWAVES UPSTREAM AS MERGING
STRONG JET DEVELOPS ACROSS THE NE CONUS. THESE FEATURES WILL ALLOW
LOW PRES TO GRADUALLY DEEPEN AND SLIDE THROUGH SRN ONTARIO AND
QUEBEC...CREATING AN OVERRUNNING EVENT AS THE SYSTEM ATTEMPTS TO
OCCLUDE. THIS IS THE MIXED PRECIP EVENT WE HAVE BEEN DISCUSSING
FOR SOME TIME NOW. NOW THAT NAM HAS CAPTURED IT...IT APPEARS
COLDER THAN MOST OF THE DETERMINISTIC GUIDANCE...WHILE THE ECMWF
STARTS COLD AND SHIFTS TO THE WARMER SIDE OF THE ENVELOPE DUE TO
THE FACT THAT IT IS MORE AMPLIFIED THAN OTHER MODELS. THE
GFS...ECENS/GEFS MEANS ARE ACTUALLY A GOOD MIDDLE GROUND HERE.
THIS BLEND WILL BE USED THROUGH THE REMAINDER OF THE LONG TERM AS
WELL TO TAKE INTO ACCOUNT THE VARIOUS SOLUTIONS.

DETAILS...

MON INTO TUE...
REMNANT SNOWFALLS WILL BE GRADUALLY COMING TO AN END THROUGH MID
MORNING MON...ALTHOUGH FLURRIES MAY LINGER A BIT LONGER IN THE
BERKSHIRES. STRONG HIGH PRES WILL THEN SLIDE ACROSS THE REGION
THROUGH TUE...WITH MAINLY DRY WX. TEMPS LOOK TO REMAIN BELOW
NORMAL GIVEN LITTLE CHANGE IN THE AIRMASS FROM PREVIOUS DAYS.

TUE NIGHT INTO WED...
OVERRUNNING EVENT EXPECTED AS WARM FRONT WILL ATTEMPT TO PUSH N
ACROSS THE REGION BUT IS LIKELY TO STRUGGLE NEAR THE SFC DUE TO
ENTRENCHED COLD AIR AND A DEEP SNOWPACK. HOWEVER...50-60 KT LLJ
WITH STRONG SLY COMPONENT WILL ALLOW UPPER LVL WARMING TON
CONTINUE UNIMPEDED. IN SPITE OF THE STRONG JET AT ONLY 3-5KFT
ABOVE THE SFC...SNOWPACK WILL MAKE MIXING DIFFICULT SO NOT
EXPECTING SIGNIFICANT WIND ISSUES AT THIS TIME.

THE COLUMN STARTS COLD ENOUGH FOR SNOW AT ONSET TUE EVENING...AND
LOOKS LIKE AS MUCH AS 0.40-0.60 OF THE TOTAL EVENT QPF FALLS AS
SNOW INITIALLY EVERYWHERE...WITH GRADUAL CHANGEOVER DURING THE
EARLY MORNING HOURS WED MORNING FROM S-N. THEREFORE...COULD SEE AT
LEAST ADVISORY IF NOT LOW-END WARNING LVL SNOWFALLS THROUGH THE
OVERNIGHT HOURS BEFORE A TRANSITION TO SLEET...THEN FREEZING RAIN.
FREEZING RAIN COULD LOCK IN FOR SOME TIME AND GIVEN THAT H93 TEMPS
/EVEN ON THE COLDEST GUIDANCE/ AN AVERAGE OF +4C DURING THE 08Z-
16Z TIMEFRAME...BUT SFC TEMPS MAY HOLD NEAR FREEZING FOR SOME TIME
GIVEN THE DEEP SNOWPACK ACROSS THE AREA. HOWEVER...STRAIGHT RAIN
FOR A TIME FROM ABOUT MID MORNING INTO THE AFTERNOON IS LIKELY
UNTIL THE PRECIP COMES TO AN END. DEPENDING ON HOW QUICKLY 2M
TEMPS REBOUND...AS MUCH AS A QUARTER INCH OF ICE CAN/T BE RULED
OUT. AGREE WITH PREVIOUS FORECASTER THAT LEANING A BIT COLDER THAN
MOS 2M TEMPS IS PROBABLY THE WAY TO GO.

MODEST UPPER LVL INSTABILITY AS WARMING OCCURS IN THE MID LVLS
COULD ALSO MEAN A PERIOD OF HEAVY PRECIP...BOTH SNOW AND RAIN.
WITH THE RAIN...COMES A RISK FOR POOR DRAINAGE FLOODING ACROSS THE
REGION AS SNOW MELTS AND DRAINS BECOME CLOGGED. PRECIP COMES TO AN
END ACROSS MOST OF THE REGION BY AFTERNOON WED...BUT MAY LINGER A
BIT NEAR THE S COAST...MORE ON THAT BELOW.

WED NIGHT INTO THU...
CONFIDENCE IN THE FORECAST CONTINUES TO DIMINISH HERE PARTIALLY
DEPENDENT ON HOW FAST THE UPPER LVL JET EXITS TO THE EAST AND HOW
AMPLIFIED THE PATTERN REMAINS IN THE WAKE OF THE LOW PRES. THE
MORE AMPLIFIED GUIDANCE...LED BY THE ECMWF KEEPS THE COLD FRONT
JUST OFFSHORE AND WITHIN THE EQUATORWARD ENTRANCE REGION OF THE
UPPER LVL JET. THIS SUGGESTS S COASTAL AREAS COULD CONTINUE TO SEE
PRECIP...POSSIBLY EVEN CHANGING BACK TO SNOW FOR A TIME WELL INTO
THE DAY ON THU. THE MORE PROGRESSIVE GUIDANCE...LED BY THE GFS
WOULD MOVE BOTH OF THESE FEATURES OFFSHORE SUCH THAT THU IS
MAINLY DRY AND BECOMING QUITE COLD AS ANOTHER ARCTIC AIRMASS
SETTLES IN. FOR NOW...WILL CONTINUE TO LEAN ON THE MORE
PROGRESSIVE GFS BUT WITH THE ECENS/GEFS SLOWER MEMBERS BLENDED IN.
THE FINAL ANSWER WILL LIKELY BE SOMEWHERE IN BETWEEN THE TWO
SOLUTIONS. IN ANY CASE...MUCH COLDER AIRMASS EXPECTED TO MOVE IN.

THU NIGHT INTO FRI NIGHT...
COLD AIRMASS ACROSS THE REGION ASSOCIATED WITH YET ANOTHER 1035+
HPA HIGH PRES. WILL LIKELY SEE HIGHS ONLY MAKING THE TEENS AND 20S
WITH LOWS BACK IN THE SINGLE DIGITS ABOVE AND BELOW ZERO.

NEXT WEEKEND...
SOME UNCERTAINTY HERE AS TO WHETHER YET ANOTHER WAVE WILL BE
EFFECT THE REGION. WILL LEAN MAINLY DRY FOR NOW AS THE AIRMASS IN
PLACE IS QUITE DRY AND THE WAVE ITSELF IS QUITE WEAK AND SHEARING
OUT.

&&

.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TODAY AND TONIGHT/...

18Z UPDATE...MODERATE CONFIDENCE.

THIS AFTERNOON...MVFR CIGS/VSBYS IN LIGHT SNOW AT BAF-BDL BUT MAINLY
VFR TO THE EAST TO START...WITH CIGS AND/OR VSBYS LOWERING TO MVFR
ACROSS THE REMAINDER OF SOUTHERN NEW ENGLAND TERMINALS BETWEEN
18Z AND 21Z IN LIGHT SNOW.

TONIGHT...MODERATE CONFIDENCE. THE BULK OF THE MODERATE TO EVEN
BRIEFLY HEAVY SNOW WILL OCCUR THIS EVENING WHEN WIDESPREAD IFR TO
LIFR CONDITIONS OCCUR. THE LOWEST CONDITIONS WILL MOST LIKELY BE
SOUTH OF THE MA TURNPIKE. PTYPE PRETTY MUCH ALL SNOW...EXCEPT FOR
THE VERY IMMEDIATE SOUTH COAST/CAPE WHERE SNOW MAY MIX WITH OR
CHANGE TO RAIN FOR A TIME. WHETHER OR NOT THAT HAPPENS IS
UNCERTAIN...BUT WE DO THINK THAT AT LEAST THE ISLANDS WILL MIX OR CHANGE
TO RAIN.

BULK OF SNOW ENDS BY 8Z TO 9Z TONIGHT AND MUCH OF THE THE REGION
SHOULD IMPROVE TO VFR CONDITIONS BY 12-13Z MONDAY.

KBOS TAF...CONFIDENT IN OVERALL TRENDS BUT THERE IS UNCERTAINTY ON
TIMING. SOME LIGHT SNOW IS EXPECTED DURING MID TO LATE
AFTERNOON...BUT THE BULK OF ACCUMULATING SNOW WITH IFR TO LIFR
CONDITIONS EXPECTED MAINLY THIS EVENING.

KBDL TAF...CONFIDENT IN OVERALL TRENDS BUT THERE IS UNCERTAINTY ON
TIMING. BULK OF ACCUMULATING SNOW WITH IFR TO LIFR CONDITIONS
EXPECTED AFTER 3 OR 4 PM.

OUTLOOK...MONDAY THROUGH THURSDAY...

MONDAY...HIGH CONFIDENCE.
IFR/MVFR IN REMNANT SNOWS END EARLY...WITH TRANSITION TO VFR
EVERYWHERE BY AFTERNOON. W-NW WIND GUSTS UP TO AROUND 30 KT AT
TIMES DURING THE AFTERNOON AND EVENING.

MON NIGHT INTO TUE...HIGH CONFIDENCE.
MAINLY VFR. WINDS DIMINISH MON NIGHT.

TUE NIGHT INTO THU...MODERATE CONFIDENCE.
A MESSY PERIOD. SNOW BEGINS EVERYWHERE LATE TUE INTO WED NIGHT
WITH MODERATE ACCUMS POSSIBLE...THEN EXPECT GRADUALLY TRANSITION
TO SLEET AND FREEZING RAIN DURING THE EARLY MORNING HOURS
WED...THEN TO ALL RAIN DURING THE DAY ON WED. SOME ICE ACCUM
POSSIBLE AS WELL. THE RAIN DIMINISHES LATE WED BUT MAY LINGER
ALONG THE S COAST AND EVEN CHANGE TO SNOW INTO THE DAY ON THU.
EXPECT PERIODS OF IFR/LIFR CONDITIONS THROUGHOUT THE PERIOD WITH
SOME IMPROVEMENT FROM N-S ON THU. LLWS LIKELY ESPECIALLY TUE NIGHT
AND EARLY WED.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TODAY AND TONIGHT/...HIGH CONFIDENCE.

A WEAK WAVE OF LOW PRESSURE MOVES ACROSS THE WATERS LATER
TODAY AND TONIGHT.  WEAK PRESSURE GRADIENT SHOULD KEEP
WINDS/SEAS BELOW SMALL CRAFT THRESHOLDS TODAY AND TONIGHT.  THE
SYSTEM REALLY INTENSIFIES AS IT MOVES INTO THE CANADIAN MARITIMES
NEAR DAYBREAK MONDAY...SO WESTERLY WIND GUSTS MAY REACH 20 TO 25
KNOTS NEAR 12Z MONDAY.  OTHERWISE...RAIN AND SNOW LATE TODAY AND
ESPECIALLY TONIGHT WILL REDUCE VISIBILITIES AT TIMES FOR MARINERS.

OUTLOOK...MONDAY THROUGH THURSDAY..MODERATE CONFIDENCE.

MONDAY INTO MONDAY NIGHT...HIGH CONFIDENCE.
WINDS BEGIN OUT OF THE SW THEN SHIFT TO W-NW IN THE AFTERNOON.
WIND GUSTS REACH 35-40 KT DURING THE AFTERNOON AND OVERNIGHT SO
WILL BE ISSUING A GALE WATCH. SEAS BUILD 10-12 FT ON THE OCEAN
WATERS. SOME LIGHT FREEZING SPRAY POSSIBLE MON EVENING INTO TUE
MORNING.

TUE...HIGH CONFIDENCE.
WINDS AND SEAS START AT OR AROUND SMALL CRAFT ADVISORY THRESHOLDS
BUT THEN DROP DURING THE DAY SUCH THAT A PERIOD OF QUIET BOATING
WEATHER IS LIKELY TUE AFTERNOON AND EVENING.

TUE NIGHT INTO THU...MODERATE CONFIDENCE.
LOW PRES PASSES WELL INLAND...WITH WINDS OUT OF THE S GRADUALLY
SHIFTING TO THE W LATE WED INTO THU. PERIODS OF WIND GUSTS 25-30
KT EXPECTED ALTHOUGH GUSTS MAY APPROACH GALE FORCE WED EVENING.
SEAS BUILD THROUGH WED TO AROUND 7-10FT ON THE OCEAN WATERS THEN
DIMINISH THU. AT THE VERY LEAST SMALL CRAFT ADVISORIES ARE LIKELY
DURING THIS PERIOD. PERIODS OF SNOW CHANGING TO RAIN EARLY WED
WITH SOME LOW VSBYS IN RAIN AND FOG ON WED.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR CTZ002>004.
MA...WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR MAZ002>016-
     022>024-026.
     WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR MAZ017>021.
RI...WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR RIZ001-008.
     WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR RIZ002>007.
MARINE...GALE WATCH FROM MONDAY MORNING THROUGH LATE MONDAY NIGHT FOR
     ANZ231>235-237-250-251-254>256.

&&

$$
SYNOPSIS...FRANK/DOODY
NEAR TERM...FRANK/DOODY/NMB
SHORT TERM...FRANK
LONG TERM...DOODY
AVIATION...FRANK/DOODY/NMB
MARINE...FRANK/DOODY




000
FXUS61 KBOX 011810
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
110 PM EST SUN MAR 1 2015

.SYNOPSIS...
A FAST MOVING LOW PRESSURE SYSTEM WILL BRING ACCUMULATING SNOW
LATER TODAY AND ESPECIALLY TONIGHT WITH THE HIGHEST AMOUNTS
EXPECTED SOUTH OF THE MASSACHUSETTS TURNPIKE. HIGH PRESSURE
BRINGS DRY COLD AIR FOR THE EARLY WEEK. LOW PRESSURE FROM NORTHERN
CANADA AND ASSOCIATED LOW FORMING OVER THE PLAINS MONDAY WILL
MERGE...THEN PASS WEST AND NORTH OF NEW ENGLAND. THIS WILL SWING A
COLD FRONT ACROSS THE REGION ON WEDNESDAY. DRY AND COLD WEATHER
RETURNS FOR THE END OF THE WEEK.

&&

.NEAR TERM /UNTIL 5 PM THIS AFTERNOON/...
1 PM UPDATE...

LIGHT SNOW IS WORKING ITS WAY INTO SOUTHERN NEW ENGLAND...BASED ON
18Z OBS LIGHT SNOW HAS MADE IT INTO THE SPRINGFIELD AREA AND LIGHT
SNOW HAS EVEN STARTED AT PVD. THE SNOW WILL CONTINUE TO GRADUALLY
OVERSPREAD THE REMAINDER OF OUR AREA AS THE AFTERNOON
PROGRESSES...LIKELY REACHING BOSTON AROUND 20Z. AGAIN ONLY MINOR CHANGES
MADE TO HOURLY TEMPS TO REFLECT LATEST OBS...FORECAST HIGHS
CONTINUE TO LOOK ON TRACK.

EARLY MORNING DISCUSSION...

MID LEVEL CLOUDINESS WILL STREAM INTO SOUTHERN NEW ENGLAND AND
THICKEN DURING THE MORNING HOURS IN ADVANCE OF APPROACHING LOW
PRESSURE.  SOUTHWEST FLOW ALOFT OVERRUNING THE COLD DOME AT THE
SURFACE MAY ALLOW FOR SOME LIGHT SNOW/FLURRIES TO BREAK
OUT ACROSS THE INTERIOR LATE THIS MORNING/EARLY AFTERNOON AND THEN
FIND THEIR WAY TO THE COAST BY MID TO LATE AFTERNOON.  THE LIFT
THROUGH MID AFTERNOON IS FAIRLY WEAK...SO THE AREAS OF SNOW SHOULD
BE RATHER LIGHT. ANY ACCUMULATIONS THAT OCCUR WILL PROBABLY BE
A DUSTING TO LESS THAN 1 INCH THROUGH THAT THAT TIME.  HIGH TEMPS
WILL MAINLY BE IN THE UPPER 20S TO AROUND 30.

&&

.SHORT TERM /5 PM THIS AFTERNOON THROUGH 6 AM MONDAY/...
*** BULK OF THE ACCUMULATING SNOW OCCURS BETWEEN 3 PM AND 1 AM WITH
  THE HEAVIEST AMOUNTS SOUTH OF THE MA TURNPIKE ***

1) OVERVIEW AND TIMING:

THE BULK OF THE ACCUMULATING SNOW WILL OCCUR BETWEEN 3 PM AND
1 AM ACROSS THE REGION.  THE SNOW SHOULD TAPER OFF TO FLURRIES
TOWARD DAYBREAK MONDAY.  THE MODELS DO AGREE THAT THE BETTER FORCING
WILL OCCUR TO THE SOUTH OF THE MA TURNPIKE.  THIS A RESULT
OF SECONDARY LOW PRESSURE NEAR THE SOUTH COAST...ALLOWING FOR
SOME SURFACE CONVERGENCE AS WELL AS THE INTENSIFICATION OF THE LOW
LEVEL JET.

THE BIGGEST ISSUE IS THE MODELS ARE NOT IN AGREEMENT IN HOW
INTENSE THE FORCING WILL BE ACROSS THE REGION THIS EVENING.  THE
RGEM/NAM ARE THE MOST ROBUST WITH QPF SOUTH OF THE MA TURNPIKE.  THE
NAM SHOWS A PERIOD OF FAIRLY STRONG LIFT OF 15 TO 20 MICROBARS PER
SECOND WITHIN THE BEST SNOWGROWTH REGION THIS EVENING.  THIS WOULD
TRANSLATE TO A PERIOD OF 1+ INCH PER HOUR SNOWFALL RATES NEAR AND
SOUTH OF THE MA PIKE.  ON THE OTHER HAND...THE GFS ALSO HAS FAIRLY
STRONG LIFT...BUT KEEPS IT SOUTHEAST OF OUR REGION OUT OVER THE
OCEAN.  THE SECONDARY LOW PRESSURE SYSTEM ON THE GFS IS WEAKER AND
FURTHER SOUTHEAST...RESULTING IN THE LOW LEVEL JET BEING DISPLACED
FURTHER EAST.  THE ECMWF/UKMET SOLUTIONS SEEM TO BE THE MIDDLE
GROUND WHICH WE WILL LEAN TOWARDS.

2) WINTER WEATHER HEADLINES AND SNOW ACCUMS:

WITH THAT SAID...THE OTHER DILEMMA IS WHAT TO DO WITH THE CURRENT
HEADLINES.  THIS DOES NOT APPEAR TO BE THE TYPE OF SETUP WHERE WE
ARE GOING TO RECEIVE WIDESPREAD WARNING SNOWFALL AMOUNTS.  THE
WINDOW FOR THE VERY STRONG LIFT/FORCING IS SHORT-LIVED AND REALLY
WOULD LIKE TO SEE THE LOW LEVEL JET A BIT MORE BACKED TO TRANSPORT
DEEPER MOISTURE NORTHWARD.  THEREFORE...FEEL THAT FOR MOST OF THE
REGION WINTER WEATHER ADVISORY/S FOR 3 TO 6 INCHES OF SNOW WILL
COVER IT.  HOWEVER...GIVEN THERE IS NICE OMEGA IN THE SNOW GROWTH
REGION...WE MIGHT BE LOOKING AT SOME DECENT RATIOS.  SO WE STILL CAN
NOT RULE OUT THE LOW RISK OF REACHING WARNING AMOUNTS AND LATER
SHIFTS WILL HAVE TO MONITOR CLOSELY...ESPECIALLY ACROSS NORTHERN CT
AND NORTHWEST RI.

WE DID UPGRADE A SMALL AREA FROM CENTRAL AND SOUTHERN RHODE ISLAND
INTO SOUTHEAST MA INCLUDING THE SOUTH COAST TO A WINTER
STORM WARNING.  THE NOSE OF THE LOW LEVEL JET LOOKS TO TRANSPORT
SOME DEEPER MOISTURE INTO THIS REGION.  THERE ALSO COULD BE SOME
ENHANCEMENT ALONG THE LAND/SEA INTERFACE AND A WEAK SURFACE
BOUNDARY SO WENT WITH 4 TO 8 INCHES IN THIS REGION.

3) PTYPE AND IMPACTS:

THE MODELS HAVE TRENDED COLDER OVER THE PAST 24 HOURS.
THEREFORE...EXPECT THIS BE PRETTY MUCH A SNOW EVENT.  IT DOES BECOME
A VERY CLOSE CALL NEAR THE SOUTH COAST...BUT WERE LEANING TOWARDS IT
STAYING MAINLY WET SNOW.  IF PRECIPITATION LIGHTENS UP THAT MAY
INCREASE THIS RISK WE SEE A BRIEF CHANGE OVER TO RAIN.
MEANWHILE...WE WENT WITH A HIGH END WINTER WEATHER ADVISORY FOR THE
CAPE BECAUSE THEY MAY CHANGE TO RAIN FOR A TIME...ESPECIALLY EAST OF
HYANNIS.  IF THE CHANGE OVER DOES NOT OCCUR...WE MAY NEED TO UPGRADE
THEM TO A WINTER STORM WARNING ESPECIALLY NEAR THE CAPE COD CANAL
GIVEN EXPECTED QPF.

THE ONE THING WILL ALSO HAVE TO WATCH IS AREAS NEAR THE SOUTH COAST
AND CAPE COD.  LOOKS TO BE A WET SNOW DOWN THAT WAY AND ON GOING
ROOF ISSUES MAY BE EXACERBATED...ESPECIALLY IF ANY AREAS THAT ARE
ABLE TO EXCEED 6 INCHES OF WET SNOW.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
HIGHLIGHTS...

  * BLUSTERY CONDITIONS ON MON WITH DRY WEATHER CONTINUING INTO
    TUE.
  * A STORM SYSTEM BRINGS MIXED PRECIP TUE INTO WED.
  * CONDITIONS IMPROVE THU BUT BECOMING COLD AGAIN.

OVERVIEW AND MODEL PREFERENCES...
A SPLIT FLOW MERGER WILL BE THE DEFINING FACTOR THROUGH THE LONG
TERM FORECAST PERIOD. IN THE MID TERM...THE STREAMS MERGE THANKS
TO PHASING OF NRN AND SRN STREAM SHORTWAVES UPSTREAM AS MERGING
STRONG JET DEVELOPS ACROSS THE NE CONUS. THESE FEATURES WILL ALLOW
LOW PRES TO GRADUALLY DEEPEN AND SLIDE THROUGH SRN ONTARIO AND
QUEBEC...CREATING AN OVERRUNNING EVENT AS THE SYSTEM ATTEMPTS TO
OCCLUDE. THIS IS THE MIXED PRECIP EVENT WE HAVE BEEN DISCUSSING
FOR SOME TIME NOW. NOW THAT NAM HAS CAPTURED IT...IT APPEARS
COLDER THAN MOST OF THE DETERMINISTIC GUIDANCE...WHILE THE ECMWF
STARTS COLD AND SHIFTS TO THE WARMER SIDE OF THE ENVELOPE DUE TO
THE FACT THAT IT IS MORE AMPLIFIED THAN OTHER MODELS. THE
GFS...ECENS/GEFS MEANS ARE ACTUALLY A GOOD MIDDLE GROUND HERE.
THIS BLEND WILL BE USED THROUGH THE REMAINDER OF THE LONG TERM AS
WELL TO TAKE INTO ACCOUNT THE VARIOUS SOLUTIONS.

DETAILS...

MON INTO TUE...
REMNANT SNOWFALLS WILL BE GRADUALLY COMING TO AN END THROUGH MID
MORNING MON...ALTHOUGH FLURRIES MAY LINGER A BIT LONGER IN THE
BERKSHIRES. STRONG HIGH PRES WILL THEN SLIDE ACROSS THE REGION
THROUGH TUE...WITH MAINLY DRY WX. TEMPS LOOK TO REMAIN BELOW
NORMAL GIVEN LITTLE CHANGE IN THE AIRMASS FROM PREVIOUS DAYS.

TUE NIGHT INTO WED...
OVERRUNNING EVENT EXPECTED AS WARM FRONT WILL ATTEMPT TO PUSH N
ACROSS THE REGION BUT IS LIKELY TO STRUGGLE NEAR THE SFC DUE TO
ENTRENCHED COLD AIR AND A DEEP SNOWPACK. HOWEVER...50-60 KT LLJ
WITH STRONG SLY COMPONENT WILL ALLOW UPPER LVL WARMING TON
CONTINUE UNIMPEDED. IN SPITE OF THE STRONG JET AT ONLY 3-5KFT
ABOVE THE SFC...SNOWPACK WILL MAKE MIXING DIFFICULT SO NOT
EXPECTING SIGNIFICANT WIND ISSUES AT THIS TIME.

THE COLUMN STARTS COLD ENOUGH FOR SNOW AT ONSET TUE EVENING...AND
LOOKS LIKE AS MUCH AS 0.40-0.60 OF THE TOTAL EVENT QPF FALLS AS
SNOW INITIALLY EVERYWHERE...WITH GRADUAL CHANGEOVER DURING THE
EARLY MORNING HOURS WED MORNING FROM S-N. THEREFORE...COULD SEE AT
LEAST ADVISORY IF NOT LOW-END WARNING LVL SNOWFALLS THROUGH THE
OVERNIGHT HOURS BEFORE A TRANSITION TO SLEET...THEN FREEZING RAIN.
FREEZING RAIN COULD LOCK IN FOR SOME TIME AND GIVEN THAT H93 TEMPS
/EVEN ON THE COLDEST GUIDANCE/ AN AVERAGE OF +4C DURING THE 08Z-
16Z TIMEFRAME...BUT SFC TEMPS MAY HOLD NEAR FREEZING FOR SOME TIME
GIVEN THE DEEP SNOWPACK ACROSS THE AREA. HOWEVER...STRAIGHT RAIN
FOR A TIME FROM ABOUT MID MORNING INTO THE AFTERNOON IS LIKELY
UNTIL THE PRECIP COMES TO AN END. DEPENDING ON HOW QUICKLY 2M
TEMPS REBOUND...AS MUCH AS A QUARTER INCH OF ICE CAN/T BE RULED
OUT. AGREE WITH PREVIOUS FORECASTER THAT LEANING A BIT COLDER THAN
MOS 2M TEMPS IS PROBABLY THE WAY TO GO.

MODEST UPPER LVL INSTABILITY AS WARMING OCCURS IN THE MID LVLS
COULD ALSO MEAN A PERIOD OF HEAVY PRECIP...BOTH SNOW AND RAIN.
WITH THE RAIN...COMES A RISK FOR POOR DRAINAGE FLOODING ACROSS THE
REGION AS SNOW MELTS AND DRAINS BECOME CLOGGED. PRECIP COMES TO AN
END ACROSS MOST OF THE REGION BY AFTERNOON WED...BUT MAY LINGER A
BIT NEAR THE S COAST...MORE ON THAT BELOW.

WED NIGHT INTO THU...
CONFIDENCE IN THE FORECAST CONTINUES TO DIMINISH HERE PARTIALLY
DEPENDENT ON HOW FAST THE UPPER LVL JET EXITS TO THE EAST AND HOW
AMPLIFIED THE PATTERN REMAINS IN THE WAKE OF THE LOW PRES. THE
MORE AMPLIFIED GUIDANCE...LED BY THE ECMWF KEEPS THE COLD FRONT
JUST OFFSHORE AND WITHIN THE EQUATORWARD ENTRANCE REGION OF THE
UPPER LVL JET. THIS SUGGESTS S COASTAL AREAS COULD CONTINUE TO SEE
PRECIP...POSSIBLY EVEN CHANGING BACK TO SNOW FOR A TIME WELL INTO
THE DAY ON THU. THE MORE PROGRESSIVE GUIDANCE...LED BY THE GFS
WOULD MOVE BOTH OF THESE FEATURES OFFSHORE SUCH THAT THU IS
MAINLY DRY AND BECOMING QUITE COLD AS ANOTHER ARCTIC AIRMASS
SETTLES IN. FOR NOW...WILL CONTINUE TO LEAN ON THE MORE
PROGRESSIVE GFS BUT WITH THE ECENS/GEFS SLOWER MEMBERS BLENDED IN.
THE FINAL ANSWER WILL LIKELY BE SOMEWHERE IN BETWEEN THE TWO
SOLUTIONS. IN ANY CASE...MUCH COLDER AIRMASS EXPECTED TO MOVE IN.

THU NIGHT INTO FRI NIGHT...
COLD AIRMASS ACROSS THE REGION ASSOCIATED WITH YET ANOTHER 1035+
HPA HIGH PRES. WILL LIKELY SEE HIGHS ONLY MAKING THE TEENS AND 20S
WITH LOWS BACK IN THE SINGLE DIGITS ABOVE AND BELOW ZERO.

NEXT WEEKEND...
SOME UNCERTAINTY HERE AS TO WHETHER YET ANOTHER WAVE WILL BE
EFFECT THE REGION. WILL LEAN MAINLY DRY FOR NOW AS THE AIRMASS IN
PLACE IS QUITE DRY AND THE WAVE ITSELF IS QUITE WEAK AND SHEARING
OUT.

&&

.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TODAY AND TONIGHT/...

18Z UPDATE...MODERATE CONFIDENCE.

THIS AFTERNOON...MVFR CIGS/VSBYS IN LIGHT SNOW AT BAF-BDL BUT MAINLY
VFR TO THE EAST TO START...WITH CIGS AND/OR VSBYS LOWERING TO MVFR
ACROSS THE REMAINDER OF SOUTHERN NEW ENGLAND TERMINALS BETWEEN
18Z AND 21Z IN LIGHT SNOW.

TONIGHT...MODERATE CONFIDENCE. THE BULK OF THE MODERATE TO EVEN
BRIEFLY HEAVY SNOW WILL OCCUR THIS EVENING WHEN WIDESPREAD IFR TO
LIFR CONDITIONS OCCUR. THE LOWEST CONDITIONS WILL MOST LIKELY BE
SOUTH OF THE MA TURNPIKE. PTYPE PRETTY MUCH ALL SNOW...EXCEPT FOR
THE VERY IMMEDIATE SOUTH COAST/CAPE WHERE SNOW MAY MIX WITH OR
CHANGE TO RAIN FOR A TIME. WHETHER OR NOT THAT HAPPENS IS
UNCERTAIN...BUT WE DO THINK THAT AT LEAST THE ISLANDS WILL MIX OR CHANGE
TO RAIN.

BULK OF SNOW ENDS BY 8Z TO 9Z TONIGHT AND MUCH OF THE THE REGION
SHOULD IMPROVE TO VFR CONDITIONS BY 12-13Z MONDAY.

KBOS TAF...CONFIDENT IN OVERALL TRENDS BUT THERE IS UNCERTAINTY ON
TIMING. SOME LIGHT SNOW IS EXPECTED DURING MID TO LATE
AFTERNOON...BUT THE BULK OF ACCUMULATING SNOW WITH IFR TO LIFR
CONDITIONS EXPECTED MAINLY THIS EVENING.

KBDL TAF...CONFIDENT IN OVERALL TRENDS BUT THERE IS UNCERTAINTY ON
TIMING. BULK OF ACCUMULATING SNOW WITH IFR TO LIFR CONDITIONS
EXPECTED AFTER 3 OR 4 PM.

OUTLOOK...MONDAY THROUGH THURSDAY...

MONDAY...HIGH CONFIDENCE.
IFR/MVFR IN REMNANT SNOWS END EARLY...WITH TRANSITION TO VFR
EVERYWHERE BY AFTERNOON. W-NW WIND GUSTS UP TO AROUND 30 KT AT
TIMES DURING THE AFTERNOON AND EVENING.

MON NIGHT INTO TUE...HIGH CONFIDENCE.
MAINLY VFR. WINDS DIMINISH MON NIGHT.

TUE NIGHT INTO THU...MODERATE CONFIDENCE.
A MESSY PERIOD. SNOW BEGINS EVERYWHERE LATE TUE INTO WED NIGHT
WITH MODERATE ACCUMS POSSIBLE...THEN EXPECT GRADUALLY TRANSITION
TO SLEET AND FREEZING RAIN DURING THE EARLY MORNING HOURS
WED...THEN TO ALL RAIN DURING THE DAY ON WED. SOME ICE ACCUM
POSSIBLE AS WELL. THE RAIN DIMINISHES LATE WED BUT MAY LINGER
ALONG THE S COAST AND EVEN CHANGE TO SNOW INTO THE DAY ON THU.
EXPECT PERIODS OF IFR/LIFR CONDITIONS THROUGHOUT THE PERIOD WITH
SOME IMPROVEMENT FROM N-S ON THU. LLWS LIKELY ESPECIALLY TUE NIGHT
AND EARLY WED.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TODAY AND TONIGHT/...HIGH CONFIDENCE.

A WEAK WAVE OF LOW PRESSURE MOVES ACROSS THE WATERS LATER
TODAY AND TONIGHT.  WEAK PRESSURE GRADIENT SHOULD KEEP
WINDS/SEAS BELOW SMALL CRAFT THRESHOLDS TODAY AND TONIGHT.  THE
SYSTEM REALLY INTENSIFIES AS IT MOVES INTO THE CANADIAN MARITIMES
NEAR DAYBREAK MONDAY...SO WESTERLY WIND GUSTS MAY REACH 20 TO 25
KNOTS NEAR 12Z MONDAY.  OTHERWISE...RAIN AND SNOW LATE TODAY AND
ESPECIALLY TONIGHT WILL REDUCE VISIBILITIES AT TIMES FOR MARINERS.

OUTLOOK...MONDAY THROUGH THURSDAY..MODERATE CONFIDENCE.

MONDAY INTO MONDAY NIGHT...HIGH CONFIDENCE.
WINDS BEGIN OUT OF THE SW THEN SHIFT TO W-NW IN THE AFTERNOON.
WIND GUSTS REACH 35-40 KT DURING THE AFTERNOON AND OVERNIGHT SO
WILL BE ISSUING A GALE WATCH. SEAS BUILD 10-12 FT ON THE OCEAN
WATERS. SOME LIGHT FREEZING SPRAY POSSIBLE MON EVENING INTO TUE
MORNING.

TUE...HIGH CONFIDENCE.
WINDS AND SEAS START AT OR AROUND SMALL CRAFT ADVISORY THRESHOLDS
BUT THEN DROP DURING THE DAY SUCH THAT A PERIOD OF QUIET BOATING
WEATHER IS LIKELY TUE AFTERNOON AND EVENING.

TUE NIGHT INTO THU...MODERATE CONFIDENCE.
LOW PRES PASSES WELL INLAND...WITH WINDS OUT OF THE S GRADUALLY
SHIFTING TO THE W LATE WED INTO THU. PERIODS OF WIND GUSTS 25-30
KT EXPECTED ALTHOUGH GUSTS MAY APPROACH GALE FORCE WED EVENING.
SEAS BUILD THROUGH WED TO AROUND 7-10FT ON THE OCEAN WATERS THEN
DIMINISH THU. AT THE VERY LEAST SMALL CRAFT ADVISORIES ARE LIKELY
DURING THIS PERIOD. PERIODS OF SNOW CHANGING TO RAIN EARLY WED
WITH SOME LOW VSBYS IN RAIN AND FOG ON WED.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR CTZ002>004.
MA...WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR MAZ002>016-
     022>024-026.
     WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR MAZ017>021.
RI...WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR RIZ001-008.
     WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR RIZ002>007.
MARINE...GALE WATCH FROM MONDAY MORNING THROUGH LATE MONDAY NIGHT FOR
     ANZ231>235-237-250-251-254>256.

&&

$$
SYNOPSIS...FRANK/DOODY
NEAR TERM...FRANK/DOODY/NMB
SHORT TERM...FRANK
LONG TERM...DOODY
AVIATION...FRANK/DOODY/NMB
MARINE...FRANK/DOODY



000
FXUS61 KGYX 011643
AFDGYX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
1143 AM EST SUN MAR 1 2015

.SYNOPSIS...
LOW PRESSURE WILL MOVE IN FROM THE WEST THIS AFTERNOON AND WILL
CROSS THE REGION OVERNIGHT...PRODUCING SOME LIGHT SNOW. A STRONG
NORTHWEST FLOW WILL SET UP IN ITS WAKE ON MONDAY. HIGH PRESSURE
WILL BUILD IN FROM THE WEST MONDAY NIGHT AND WILL CREST OVER THE
REGION EARLY TUESDAY BEFORE MOVING OFFSHORE. LOW PRESSURE WILL
SWING THROUGH SOUTHERN CANADA TUESDAY NIGHT PUSHING A WARM NORTH
ACROSS THE REGION...AND PRODUCING A PERIOD OF SNOW...SLEET...OR
FREEZING RAIN. AS THE LOW SHIFT TO OUT NORTH...IT WILL DRAG A COLD
FRONT THROUGH THE REGION ON WEDNESDAY. HIGH PRESSURE WILL BUILD IN
FROM THE WEST THURSDAY AND WILL CREST OVER THE REGION ON FRIDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
UPDATE...
HAVE UPDATED GRIDS BASED ON CURRENT OBSERVATIONS AND TRENDS.
HAVE MADE MINOR ADJUSTMENTS TO FORECAST HIGHS AS SOME AREAS
STRUGGLING TO CLIMB THROUGH THE 20S WITH CLOUD COVER.

SNOW CONTINUES TO PROGRESS EAST...HOWEVER MUCH OF THIS IS
INITIALLY DRYING UP WITH VERY DRY INITIAL CONDITIONS IN MAINE AND
NEW HAMPSHIRE WITH DEW POINTS STILL BELOW ZERO. SNOW WILL ENTER
SOUTHWEST NEW HAMPSHIRE DURING THE MID TO LATE AFTERNOON HOURS
BEFORE SPREADING EAST.

PREV DISC...
CLOUDS WILL INCREASE AND THICKEN ACROSS THE REGION THIS MORNING
THROUGH MID AFTERNOON AS WEAK LOW PRESSURE PUSHES IN FROM THE
WEST. WILL SEE LIGHT SNOW BREAKING OUT IN NEW HAMPSHIRE DURING THE
MID TO LATE AFTERNOON AND THIS WILL PUSH EAST INTO WESTERN MAINE
THROUGH EARLY EVENING. ONLY LOOKING AT ACCUMULATIONS OF AN INCH OR
LESS THROUGH THE END OF THE DAY WITH MOST OF THAT IN SOUTHERN NEW
HAMPSHIRE. ONCE AGAIN TEMPERATURES WILL REMAIN BELOW NORMAL WITH
HIGH GENERALLY RANGING THROUGH THE 20S.

&&

.SHORT TERM /MONDAY/...
LIGHT SNOW WILL CONTINUE OVERNIGHT THROUGHOUT THE FORECAST AREA AS
LOW PRESSURE PUSHES THROUGH THE REGION. STORM TOTALS FOR MUCH OF
THE FORECAST AREA WILL BE IN THE 1 TO 3 INCH RANGE ALTHOUGH
SOUTHERN NEW HAMPSHIRE MAY SEE LOCALLY HIGHER AMOUNTS OF 2 TO 4
INCHES. LOWS TEMPS WILL BOTTOM OUT IN THE TEENS NORTH AND 20S
SOUTH.

TRAILING COLD FRONT WILL CROSS THE REGION MONDAY MORNING AS LOW
PRESSURE SHIFTS INTO THE MARITIMES. EXPECT ANY LINGERING SNOW
SHOWERS TO END BY LATE MORNING DOWNWIND OF THE MOUNTAINS WITH
PARTIAL CLEARING IN THE AFTERNOON AS STRONG NORTHWEST FLOW SETS UP
BEHIND THE FRONT. INCREASING UPSLOPE FLOW AND LOW LEVEL MOISTURE WILL
KEEP SNOW SHOWERS GOING IN THE MOUNTAINS. EXPECT HIGH TEMPS TO BE
REACHED IN THE MORNING BEFORE DROPPING BACK IN THE AFTERNOON.
HIGHS WILL RANGE FROM THE MID 20S TO LOWER 30S NORTH AND LOWER TO
MID 30S SOUTH.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
MODELS CONTINUE SUGGEST CHANGES TO THE NRN HEMISPHERE 500 MB
PATTERN....WITH SHORTER WAVELENGTHS IN THE FLOW...AND LESS
ESTABLISHED BLOCKING. THIS WILL GENERALLY MAKE FOR A MORE
PROGRESSIVE PATTERN...AND MAY ALLOW SOME WARMER AIR TO BEGIN TO
NUDGE POLEWARD. THE PROGRESSIVE PATTERN WILL ALSO LIMIT THE
DEVELOPMENT OF ANY SIGNIFICANT ERN CONUS STORMS.

MON EVE STARTS OFF WITH GUSTY NW FLOW AND SOME MN SHSN...BUT THE
WINDS AND SHSN WILL BEGIN TO DIMINISH BEFORE MIDNIGHT...AND
CONTINUE TO DO SO OVERNIGHT. SOME LATE RAD COOLING WILL ALLOW
TEMPS TO FALL TO AROUND ZERO IN THE NORTH...AND AROUND 10 ABOVE
ALONG THE COAST /WHICH COMPARED TO RECENTLY IS NOT AS COLD...BUT
STILL ABOUT 10 DEGREES BLO NORMAL/. TUE WILL START OFF SUNNY...BUT
INCREASING MID-HIGH CLOUDS OVERSPREAD THE REGION FROM SW-NE...WITH
AN CHANCE FOR SOME LIGHT SN IN SW NH LATE IN THE
AFTERNOON...ALTHOUGH IN GENERALLY THE PRECIP WILL HOLD OFF UNTIL
TUE NIGHT.

TUE NIGHT WILL SEE MAINLY WAA PRECIP STARTING OFF AS SNOW
CONTINUING THROUGH THE EVENING AND INTO THE EVENING. BY THE PRE-
DAWN HOURS WILL START TO ABV FREEZING AIR WORKING ALOFT...MAINLY
ACROSS THE SRN HALF OF NH AND SW ME....AND COULD SEE PRECIP CHANGE
OVER TO PL/FZRA FOR A TIME. HOWEVER...BULK OF THE OVERNIGHT WILL
BE SNOW...AND SEVERAL INCHES ARE POSSIBLE BEFORE ANY CHANGE IN THE
S AND W ZONES...AS WELL AS THE REST OF THE CWA WHERE SNOW
CONTINUES THRU THE NIGHT. OVERALL QPF ARE RUNNING 0.25-0.5" ATTM.
GENERALLY THE MODELS ARE MORE PROGRESSIVE WITH THIS FIRST WAVE AND
PRECIP MOVES OUT WED MORNING...ALTHOUGH IT COULD END AS A A
LITTLE FZRA OR JUST PLAIN RAIN ON THE COAST AND IN SRN NH AS TEMPS
WILL BE RISING THRU THE TUE NIGHT AND ON WED....WHEN HIGHS COULD
TOP AROUND 40 IN MANY SPOTS.

MODEL CONSENSUS WOULD KEEP THE WEAK COLD FRONT THAT MOVES THRU
LATE WED STALLED WELL TO OUR S...AND HAVE LITTLE IMPACT ON THE
AREA THU. HOWEVER...THE HEMI CMC LIFTS IT BACK FAR ENOUGH N TO
POSSIBLY BRUSH THE COAST WITH A LITTLE PRECIP...AND THE CMC HAS
BEEN PERFORMING WELL THIS WINTER...SO SOMETHING TO KEEP AN EYE ON
FOR NOW. EITHER WAY...THE KICKER TROUGH MOVES THROUGH ON THU AND
IT TURNS COLDER AGAIN FOR FRI AND SAT...ALTHOUGH HIGHS WILL GET
INTO THE 20S TO AROUND 30 FRI/SAT...THIS IS STILL 10 DEGREES OR
SO BLO NORMAL.

&&

.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
SHORT TERM...MVFR/IFR CEILINGS/VSBY DEVELOPING THIS AFTERNOON AND
PERSISTING OVERNIGHT. BECOMING VFR ON MONDAY WITH AREAS OF MVFR
CEILINGS/VSBY IN THE MOUNTAINS.

LONG TERM...WILL LKLY SEE A PERIOD OF IFR AT ALL TERMINALS IN
SNOW TUE NIGHT INTO WED MORNING. KLEB/KCON/KMHT/KPWM ALL COULD SEE
A BRIEF PERIOD OF PL/FZRA LATE TUE NIGHT INTO EARLY WED.
IMPROVEMENT TO VFR EXPECTED WED AFTERNOON THROUGH THU.

&&

.MARINE...
SHORT TERM...NO FLAGS TODAY OR TONIGHT. GALES LIKELY ON MONDAY.

LONG TERM...GALES WILL LINGER INTO MON EVE...BUT SHOULD DIMINISH
DURING THE OVERNIGHT. THESE WINDS WILL BE USHERING ANOTHER ROUND
COLD AIR...AND FREEZING SPRAY IS LIKELY MON NIGHT INTO EARLY TUE.
SCA MAY BE NEEDED TUE NIGHT IN SW FLOW.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.

&&

$$




000
FXUS61 KGYX 011643
AFDGYX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
1143 AM EST SUN MAR 1 2015

.SYNOPSIS...
LOW PRESSURE WILL MOVE IN FROM THE WEST THIS AFTERNOON AND WILL
CROSS THE REGION OVERNIGHT...PRODUCING SOME LIGHT SNOW. A STRONG
NORTHWEST FLOW WILL SET UP IN ITS WAKE ON MONDAY. HIGH PRESSURE
WILL BUILD IN FROM THE WEST MONDAY NIGHT AND WILL CREST OVER THE
REGION EARLY TUESDAY BEFORE MOVING OFFSHORE. LOW PRESSURE WILL
SWING THROUGH SOUTHERN CANADA TUESDAY NIGHT PUSHING A WARM NORTH
ACROSS THE REGION...AND PRODUCING A PERIOD OF SNOW...SLEET...OR
FREEZING RAIN. AS THE LOW SHIFT TO OUT NORTH...IT WILL DRAG A COLD
FRONT THROUGH THE REGION ON WEDNESDAY. HIGH PRESSURE WILL BUILD IN
FROM THE WEST THURSDAY AND WILL CREST OVER THE REGION ON FRIDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
UPDATE...
HAVE UPDATED GRIDS BASED ON CURRENT OBSERVATIONS AND TRENDS.
HAVE MADE MINOR ADJUSTMENTS TO FORECAST HIGHS AS SOME AREAS
STRUGGLING TO CLIMB THROUGH THE 20S WITH CLOUD COVER.

SNOW CONTINUES TO PROGRESS EAST...HOWEVER MUCH OF THIS IS
INITIALLY DRYING UP WITH VERY DRY INITIAL CONDITIONS IN MAINE AND
NEW HAMPSHIRE WITH DEW POINTS STILL BELOW ZERO. SNOW WILL ENTER
SOUTHWEST NEW HAMPSHIRE DURING THE MID TO LATE AFTERNOON HOURS
BEFORE SPREADING EAST.

PREV DISC...
CLOUDS WILL INCREASE AND THICKEN ACROSS THE REGION THIS MORNING
THROUGH MID AFTERNOON AS WEAK LOW PRESSURE PUSHES IN FROM THE
WEST. WILL SEE LIGHT SNOW BREAKING OUT IN NEW HAMPSHIRE DURING THE
MID TO LATE AFTERNOON AND THIS WILL PUSH EAST INTO WESTERN MAINE
THROUGH EARLY EVENING. ONLY LOOKING AT ACCUMULATIONS OF AN INCH OR
LESS THROUGH THE END OF THE DAY WITH MOST OF THAT IN SOUTHERN NEW
HAMPSHIRE. ONCE AGAIN TEMPERATURES WILL REMAIN BELOW NORMAL WITH
HIGH GENERALLY RANGING THROUGH THE 20S.

&&

.SHORT TERM /MONDAY/...
LIGHT SNOW WILL CONTINUE OVERNIGHT THROUGHOUT THE FORECAST AREA AS
LOW PRESSURE PUSHES THROUGH THE REGION. STORM TOTALS FOR MUCH OF
THE FORECAST AREA WILL BE IN THE 1 TO 3 INCH RANGE ALTHOUGH
SOUTHERN NEW HAMPSHIRE MAY SEE LOCALLY HIGHER AMOUNTS OF 2 TO 4
INCHES. LOWS TEMPS WILL BOTTOM OUT IN THE TEENS NORTH AND 20S
SOUTH.

TRAILING COLD FRONT WILL CROSS THE REGION MONDAY MORNING AS LOW
PRESSURE SHIFTS INTO THE MARITIMES. EXPECT ANY LINGERING SNOW
SHOWERS TO END BY LATE MORNING DOWNWIND OF THE MOUNTAINS WITH
PARTIAL CLEARING IN THE AFTERNOON AS STRONG NORTHWEST FLOW SETS UP
BEHIND THE FRONT. INCREASING UPSLOPE FLOW AND LOW LEVEL MOISTURE WILL
KEEP SNOW SHOWERS GOING IN THE MOUNTAINS. EXPECT HIGH TEMPS TO BE
REACHED IN THE MORNING BEFORE DROPPING BACK IN THE AFTERNOON.
HIGHS WILL RANGE FROM THE MID 20S TO LOWER 30S NORTH AND LOWER TO
MID 30S SOUTH.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
MODELS CONTINUE SUGGEST CHANGES TO THE NRN HEMISPHERE 500 MB
PATTERN....WITH SHORTER WAVELENGTHS IN THE FLOW...AND LESS
ESTABLISHED BLOCKING. THIS WILL GENERALLY MAKE FOR A MORE
PROGRESSIVE PATTERN...AND MAY ALLOW SOME WARMER AIR TO BEGIN TO
NUDGE POLEWARD. THE PROGRESSIVE PATTERN WILL ALSO LIMIT THE
DEVELOPMENT OF ANY SIGNIFICANT ERN CONUS STORMS.

MON EVE STARTS OFF WITH GUSTY NW FLOW AND SOME MN SHSN...BUT THE
WINDS AND SHSN WILL BEGIN TO DIMINISH BEFORE MIDNIGHT...AND
CONTINUE TO DO SO OVERNIGHT. SOME LATE RAD COOLING WILL ALLOW
TEMPS TO FALL TO AROUND ZERO IN THE NORTH...AND AROUND 10 ABOVE
ALONG THE COAST /WHICH COMPARED TO RECENTLY IS NOT AS COLD...BUT
STILL ABOUT 10 DEGREES BLO NORMAL/. TUE WILL START OFF SUNNY...BUT
INCREASING MID-HIGH CLOUDS OVERSPREAD THE REGION FROM SW-NE...WITH
AN CHANCE FOR SOME LIGHT SN IN SW NH LATE IN THE
AFTERNOON...ALTHOUGH IN GENERALLY THE PRECIP WILL HOLD OFF UNTIL
TUE NIGHT.

TUE NIGHT WILL SEE MAINLY WAA PRECIP STARTING OFF AS SNOW
CONTINUING THROUGH THE EVENING AND INTO THE EVENING. BY THE PRE-
DAWN HOURS WILL START TO ABV FREEZING AIR WORKING ALOFT...MAINLY
ACROSS THE SRN HALF OF NH AND SW ME....AND COULD SEE PRECIP CHANGE
OVER TO PL/FZRA FOR A TIME. HOWEVER...BULK OF THE OVERNIGHT WILL
BE SNOW...AND SEVERAL INCHES ARE POSSIBLE BEFORE ANY CHANGE IN THE
S AND W ZONES...AS WELL AS THE REST OF THE CWA WHERE SNOW
CONTINUES THRU THE NIGHT. OVERALL QPF ARE RUNNING 0.25-0.5" ATTM.
GENERALLY THE MODELS ARE MORE PROGRESSIVE WITH THIS FIRST WAVE AND
PRECIP MOVES OUT WED MORNING...ALTHOUGH IT COULD END AS A A
LITTLE FZRA OR JUST PLAIN RAIN ON THE COAST AND IN SRN NH AS TEMPS
WILL BE RISING THRU THE TUE NIGHT AND ON WED....WHEN HIGHS COULD
TOP AROUND 40 IN MANY SPOTS.

MODEL CONSENSUS WOULD KEEP THE WEAK COLD FRONT THAT MOVES THRU
LATE WED STALLED WELL TO OUR S...AND HAVE LITTLE IMPACT ON THE
AREA THU. HOWEVER...THE HEMI CMC LIFTS IT BACK FAR ENOUGH N TO
POSSIBLY BRUSH THE COAST WITH A LITTLE PRECIP...AND THE CMC HAS
BEEN PERFORMING WELL THIS WINTER...SO SOMETHING TO KEEP AN EYE ON
FOR NOW. EITHER WAY...THE KICKER TROUGH MOVES THROUGH ON THU AND
IT TURNS COLDER AGAIN FOR FRI AND SAT...ALTHOUGH HIGHS WILL GET
INTO THE 20S TO AROUND 30 FRI/SAT...THIS IS STILL 10 DEGREES OR
SO BLO NORMAL.

&&

.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
SHORT TERM...MVFR/IFR CEILINGS/VSBY DEVELOPING THIS AFTERNOON AND
PERSISTING OVERNIGHT. BECOMING VFR ON MONDAY WITH AREAS OF MVFR
CEILINGS/VSBY IN THE MOUNTAINS.

LONG TERM...WILL LKLY SEE A PERIOD OF IFR AT ALL TERMINALS IN
SNOW TUE NIGHT INTO WED MORNING. KLEB/KCON/KMHT/KPWM ALL COULD SEE
A BRIEF PERIOD OF PL/FZRA LATE TUE NIGHT INTO EARLY WED.
IMPROVEMENT TO VFR EXPECTED WED AFTERNOON THROUGH THU.

&&

.MARINE...
SHORT TERM...NO FLAGS TODAY OR TONIGHT. GALES LIKELY ON MONDAY.

LONG TERM...GALES WILL LINGER INTO MON EVE...BUT SHOULD DIMINISH
DURING THE OVERNIGHT. THESE WINDS WILL BE USHERING ANOTHER ROUND
COLD AIR...AND FREEZING SPRAY IS LIKELY MON NIGHT INTO EARLY TUE.
SCA MAY BE NEEDED TUE NIGHT IN SW FLOW.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.

&&

$$




000
FXUS61 KGYX 011643
AFDGYX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
1143 AM EST SUN MAR 1 2015

.SYNOPSIS...
LOW PRESSURE WILL MOVE IN FROM THE WEST THIS AFTERNOON AND WILL
CROSS THE REGION OVERNIGHT...PRODUCING SOME LIGHT SNOW. A STRONG
NORTHWEST FLOW WILL SET UP IN ITS WAKE ON MONDAY. HIGH PRESSURE
WILL BUILD IN FROM THE WEST MONDAY NIGHT AND WILL CREST OVER THE
REGION EARLY TUESDAY BEFORE MOVING OFFSHORE. LOW PRESSURE WILL
SWING THROUGH SOUTHERN CANADA TUESDAY NIGHT PUSHING A WARM NORTH
ACROSS THE REGION...AND PRODUCING A PERIOD OF SNOW...SLEET...OR
FREEZING RAIN. AS THE LOW SHIFT TO OUT NORTH...IT WILL DRAG A COLD
FRONT THROUGH THE REGION ON WEDNESDAY. HIGH PRESSURE WILL BUILD IN
FROM THE WEST THURSDAY AND WILL CREST OVER THE REGION ON FRIDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
UPDATE...
HAVE UPDATED GRIDS BASED ON CURRENT OBSERVATIONS AND TRENDS.
HAVE MADE MINOR ADJUSTMENTS TO FORECAST HIGHS AS SOME AREAS
STRUGGLING TO CLIMB THROUGH THE 20S WITH CLOUD COVER.

SNOW CONTINUES TO PROGRESS EAST...HOWEVER MUCH OF THIS IS
INITIALLY DRYING UP WITH VERY DRY INITIAL CONDITIONS IN MAINE AND
NEW HAMPSHIRE WITH DEW POINTS STILL BELOW ZERO. SNOW WILL ENTER
SOUTHWEST NEW HAMPSHIRE DURING THE MID TO LATE AFTERNOON HOURS
BEFORE SPREADING EAST.

PREV DISC...
CLOUDS WILL INCREASE AND THICKEN ACROSS THE REGION THIS MORNING
THROUGH MID AFTERNOON AS WEAK LOW PRESSURE PUSHES IN FROM THE
WEST. WILL SEE LIGHT SNOW BREAKING OUT IN NEW HAMPSHIRE DURING THE
MID TO LATE AFTERNOON AND THIS WILL PUSH EAST INTO WESTERN MAINE
THROUGH EARLY EVENING. ONLY LOOKING AT ACCUMULATIONS OF AN INCH OR
LESS THROUGH THE END OF THE DAY WITH MOST OF THAT IN SOUTHERN NEW
HAMPSHIRE. ONCE AGAIN TEMPERATURES WILL REMAIN BELOW NORMAL WITH
HIGH GENERALLY RANGING THROUGH THE 20S.

&&

.SHORT TERM /MONDAY/...
LIGHT SNOW WILL CONTINUE OVERNIGHT THROUGHOUT THE FORECAST AREA AS
LOW PRESSURE PUSHES THROUGH THE REGION. STORM TOTALS FOR MUCH OF
THE FORECAST AREA WILL BE IN THE 1 TO 3 INCH RANGE ALTHOUGH
SOUTHERN NEW HAMPSHIRE MAY SEE LOCALLY HIGHER AMOUNTS OF 2 TO 4
INCHES. LOWS TEMPS WILL BOTTOM OUT IN THE TEENS NORTH AND 20S
SOUTH.

TRAILING COLD FRONT WILL CROSS THE REGION MONDAY MORNING AS LOW
PRESSURE SHIFTS INTO THE MARITIMES. EXPECT ANY LINGERING SNOW
SHOWERS TO END BY LATE MORNING DOWNWIND OF THE MOUNTAINS WITH
PARTIAL CLEARING IN THE AFTERNOON AS STRONG NORTHWEST FLOW SETS UP
BEHIND THE FRONT. INCREASING UPSLOPE FLOW AND LOW LEVEL MOISTURE WILL
KEEP SNOW SHOWERS GOING IN THE MOUNTAINS. EXPECT HIGH TEMPS TO BE
REACHED IN THE MORNING BEFORE DROPPING BACK IN THE AFTERNOON.
HIGHS WILL RANGE FROM THE MID 20S TO LOWER 30S NORTH AND LOWER TO
MID 30S SOUTH.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
MODELS CONTINUE SUGGEST CHANGES TO THE NRN HEMISPHERE 500 MB
PATTERN....WITH SHORTER WAVELENGTHS IN THE FLOW...AND LESS
ESTABLISHED BLOCKING. THIS WILL GENERALLY MAKE FOR A MORE
PROGRESSIVE PATTERN...AND MAY ALLOW SOME WARMER AIR TO BEGIN TO
NUDGE POLEWARD. THE PROGRESSIVE PATTERN WILL ALSO LIMIT THE
DEVELOPMENT OF ANY SIGNIFICANT ERN CONUS STORMS.

MON EVE STARTS OFF WITH GUSTY NW FLOW AND SOME MN SHSN...BUT THE
WINDS AND SHSN WILL BEGIN TO DIMINISH BEFORE MIDNIGHT...AND
CONTINUE TO DO SO OVERNIGHT. SOME LATE RAD COOLING WILL ALLOW
TEMPS TO FALL TO AROUND ZERO IN THE NORTH...AND AROUND 10 ABOVE
ALONG THE COAST /WHICH COMPARED TO RECENTLY IS NOT AS COLD...BUT
STILL ABOUT 10 DEGREES BLO NORMAL/. TUE WILL START OFF SUNNY...BUT
INCREASING MID-HIGH CLOUDS OVERSPREAD THE REGION FROM SW-NE...WITH
AN CHANCE FOR SOME LIGHT SN IN SW NH LATE IN THE
AFTERNOON...ALTHOUGH IN GENERALLY THE PRECIP WILL HOLD OFF UNTIL
TUE NIGHT.

TUE NIGHT WILL SEE MAINLY WAA PRECIP STARTING OFF AS SNOW
CONTINUING THROUGH THE EVENING AND INTO THE EVENING. BY THE PRE-
DAWN HOURS WILL START TO ABV FREEZING AIR WORKING ALOFT...MAINLY
ACROSS THE SRN HALF OF NH AND SW ME....AND COULD SEE PRECIP CHANGE
OVER TO PL/FZRA FOR A TIME. HOWEVER...BULK OF THE OVERNIGHT WILL
BE SNOW...AND SEVERAL INCHES ARE POSSIBLE BEFORE ANY CHANGE IN THE
S AND W ZONES...AS WELL AS THE REST OF THE CWA WHERE SNOW
CONTINUES THRU THE NIGHT. OVERALL QPF ARE RUNNING 0.25-0.5" ATTM.
GENERALLY THE MODELS ARE MORE PROGRESSIVE WITH THIS FIRST WAVE AND
PRECIP MOVES OUT WED MORNING...ALTHOUGH IT COULD END AS A A
LITTLE FZRA OR JUST PLAIN RAIN ON THE COAST AND IN SRN NH AS TEMPS
WILL BE RISING THRU THE TUE NIGHT AND ON WED....WHEN HIGHS COULD
TOP AROUND 40 IN MANY SPOTS.

MODEL CONSENSUS WOULD KEEP THE WEAK COLD FRONT THAT MOVES THRU
LATE WED STALLED WELL TO OUR S...AND HAVE LITTLE IMPACT ON THE
AREA THU. HOWEVER...THE HEMI CMC LIFTS IT BACK FAR ENOUGH N TO
POSSIBLY BRUSH THE COAST WITH A LITTLE PRECIP...AND THE CMC HAS
BEEN PERFORMING WELL THIS WINTER...SO SOMETHING TO KEEP AN EYE ON
FOR NOW. EITHER WAY...THE KICKER TROUGH MOVES THROUGH ON THU AND
IT TURNS COLDER AGAIN FOR FRI AND SAT...ALTHOUGH HIGHS WILL GET
INTO THE 20S TO AROUND 30 FRI/SAT...THIS IS STILL 10 DEGREES OR
SO BLO NORMAL.

&&

.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
SHORT TERM...MVFR/IFR CEILINGS/VSBY DEVELOPING THIS AFTERNOON AND
PERSISTING OVERNIGHT. BECOMING VFR ON MONDAY WITH AREAS OF MVFR
CEILINGS/VSBY IN THE MOUNTAINS.

LONG TERM...WILL LKLY SEE A PERIOD OF IFR AT ALL TERMINALS IN
SNOW TUE NIGHT INTO WED MORNING. KLEB/KCON/KMHT/KPWM ALL COULD SEE
A BRIEF PERIOD OF PL/FZRA LATE TUE NIGHT INTO EARLY WED.
IMPROVEMENT TO VFR EXPECTED WED AFTERNOON THROUGH THU.

&&

.MARINE...
SHORT TERM...NO FLAGS TODAY OR TONIGHT. GALES LIKELY ON MONDAY.

LONG TERM...GALES WILL LINGER INTO MON EVE...BUT SHOULD DIMINISH
DURING THE OVERNIGHT. THESE WINDS WILL BE USHERING ANOTHER ROUND
COLD AIR...AND FREEZING SPRAY IS LIKELY MON NIGHT INTO EARLY TUE.
SCA MAY BE NEEDED TUE NIGHT IN SW FLOW.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.

&&

$$



000
FXUS61 KGYX 011643
AFDGYX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
1143 AM EST SUN MAR 1 2015

.SYNOPSIS...
LOW PRESSURE WILL MOVE IN FROM THE WEST THIS AFTERNOON AND WILL
CROSS THE REGION OVERNIGHT...PRODUCING SOME LIGHT SNOW. A STRONG
NORTHWEST FLOW WILL SET UP IN ITS WAKE ON MONDAY. HIGH PRESSURE
WILL BUILD IN FROM THE WEST MONDAY NIGHT AND WILL CREST OVER THE
REGION EARLY TUESDAY BEFORE MOVING OFFSHORE. LOW PRESSURE WILL
SWING THROUGH SOUTHERN CANADA TUESDAY NIGHT PUSHING A WARM NORTH
ACROSS THE REGION...AND PRODUCING A PERIOD OF SNOW...SLEET...OR
FREEZING RAIN. AS THE LOW SHIFT TO OUT NORTH...IT WILL DRAG A COLD
FRONT THROUGH THE REGION ON WEDNESDAY. HIGH PRESSURE WILL BUILD IN
FROM THE WEST THURSDAY AND WILL CREST OVER THE REGION ON FRIDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
UPDATE...
HAVE UPDATED GRIDS BASED ON CURRENT OBSERVATIONS AND TRENDS.
HAVE MADE MINOR ADJUSTMENTS TO FORECAST HIGHS AS SOME AREAS
STRUGGLING TO CLIMB THROUGH THE 20S WITH CLOUD COVER.

SNOW CONTINUES TO PROGRESS EAST...HOWEVER MUCH OF THIS IS
INITIALLY DRYING UP WITH VERY DRY INITIAL CONDITIONS IN MAINE AND
NEW HAMPSHIRE WITH DEW POINTS STILL BELOW ZERO. SNOW WILL ENTER
SOUTHWEST NEW HAMPSHIRE DURING THE MID TO LATE AFTERNOON HOURS
BEFORE SPREADING EAST.

PREV DISC...
CLOUDS WILL INCREASE AND THICKEN ACROSS THE REGION THIS MORNING
THROUGH MID AFTERNOON AS WEAK LOW PRESSURE PUSHES IN FROM THE
WEST. WILL SEE LIGHT SNOW BREAKING OUT IN NEW HAMPSHIRE DURING THE
MID TO LATE AFTERNOON AND THIS WILL PUSH EAST INTO WESTERN MAINE
THROUGH EARLY EVENING. ONLY LOOKING AT ACCUMULATIONS OF AN INCH OR
LESS THROUGH THE END OF THE DAY WITH MOST OF THAT IN SOUTHERN NEW
HAMPSHIRE. ONCE AGAIN TEMPERATURES WILL REMAIN BELOW NORMAL WITH
HIGH GENERALLY RANGING THROUGH THE 20S.

&&

.SHORT TERM /MONDAY/...
LIGHT SNOW WILL CONTINUE OVERNIGHT THROUGHOUT THE FORECAST AREA AS
LOW PRESSURE PUSHES THROUGH THE REGION. STORM TOTALS FOR MUCH OF
THE FORECAST AREA WILL BE IN THE 1 TO 3 INCH RANGE ALTHOUGH
SOUTHERN NEW HAMPSHIRE MAY SEE LOCALLY HIGHER AMOUNTS OF 2 TO 4
INCHES. LOWS TEMPS WILL BOTTOM OUT IN THE TEENS NORTH AND 20S
SOUTH.

TRAILING COLD FRONT WILL CROSS THE REGION MONDAY MORNING AS LOW
PRESSURE SHIFTS INTO THE MARITIMES. EXPECT ANY LINGERING SNOW
SHOWERS TO END BY LATE MORNING DOWNWIND OF THE MOUNTAINS WITH
PARTIAL CLEARING IN THE AFTERNOON AS STRONG NORTHWEST FLOW SETS UP
BEHIND THE FRONT. INCREASING UPSLOPE FLOW AND LOW LEVEL MOISTURE WILL
KEEP SNOW SHOWERS GOING IN THE MOUNTAINS. EXPECT HIGH TEMPS TO BE
REACHED IN THE MORNING BEFORE DROPPING BACK IN THE AFTERNOON.
HIGHS WILL RANGE FROM THE MID 20S TO LOWER 30S NORTH AND LOWER TO
MID 30S SOUTH.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
MODELS CONTINUE SUGGEST CHANGES TO THE NRN HEMISPHERE 500 MB
PATTERN....WITH SHORTER WAVELENGTHS IN THE FLOW...AND LESS
ESTABLISHED BLOCKING. THIS WILL GENERALLY MAKE FOR A MORE
PROGRESSIVE PATTERN...AND MAY ALLOW SOME WARMER AIR TO BEGIN TO
NUDGE POLEWARD. THE PROGRESSIVE PATTERN WILL ALSO LIMIT THE
DEVELOPMENT OF ANY SIGNIFICANT ERN CONUS STORMS.

MON EVE STARTS OFF WITH GUSTY NW FLOW AND SOME MN SHSN...BUT THE
WINDS AND SHSN WILL BEGIN TO DIMINISH BEFORE MIDNIGHT...AND
CONTINUE TO DO SO OVERNIGHT. SOME LATE RAD COOLING WILL ALLOW
TEMPS TO FALL TO AROUND ZERO IN THE NORTH...AND AROUND 10 ABOVE
ALONG THE COAST /WHICH COMPARED TO RECENTLY IS NOT AS COLD...BUT
STILL ABOUT 10 DEGREES BLO NORMAL/. TUE WILL START OFF SUNNY...BUT
INCREASING MID-HIGH CLOUDS OVERSPREAD THE REGION FROM SW-NE...WITH
AN CHANCE FOR SOME LIGHT SN IN SW NH LATE IN THE
AFTERNOON...ALTHOUGH IN GENERALLY THE PRECIP WILL HOLD OFF UNTIL
TUE NIGHT.

TUE NIGHT WILL SEE MAINLY WAA PRECIP STARTING OFF AS SNOW
CONTINUING THROUGH THE EVENING AND INTO THE EVENING. BY THE PRE-
DAWN HOURS WILL START TO ABV FREEZING AIR WORKING ALOFT...MAINLY
ACROSS THE SRN HALF OF NH AND SW ME....AND COULD SEE PRECIP CHANGE
OVER TO PL/FZRA FOR A TIME. HOWEVER...BULK OF THE OVERNIGHT WILL
BE SNOW...AND SEVERAL INCHES ARE POSSIBLE BEFORE ANY CHANGE IN THE
S AND W ZONES...AS WELL AS THE REST OF THE CWA WHERE SNOW
CONTINUES THRU THE NIGHT. OVERALL QPF ARE RUNNING 0.25-0.5" ATTM.
GENERALLY THE MODELS ARE MORE PROGRESSIVE WITH THIS FIRST WAVE AND
PRECIP MOVES OUT WED MORNING...ALTHOUGH IT COULD END AS A A
LITTLE FZRA OR JUST PLAIN RAIN ON THE COAST AND IN SRN NH AS TEMPS
WILL BE RISING THRU THE TUE NIGHT AND ON WED....WHEN HIGHS COULD
TOP AROUND 40 IN MANY SPOTS.

MODEL CONSENSUS WOULD KEEP THE WEAK COLD FRONT THAT MOVES THRU
LATE WED STALLED WELL TO OUR S...AND HAVE LITTLE IMPACT ON THE
AREA THU. HOWEVER...THE HEMI CMC LIFTS IT BACK FAR ENOUGH N TO
POSSIBLY BRUSH THE COAST WITH A LITTLE PRECIP...AND THE CMC HAS
BEEN PERFORMING WELL THIS WINTER...SO SOMETHING TO KEEP AN EYE ON
FOR NOW. EITHER WAY...THE KICKER TROUGH MOVES THROUGH ON THU AND
IT TURNS COLDER AGAIN FOR FRI AND SAT...ALTHOUGH HIGHS WILL GET
INTO THE 20S TO AROUND 30 FRI/SAT...THIS IS STILL 10 DEGREES OR
SO BLO NORMAL.

&&

.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
SHORT TERM...MVFR/IFR CEILINGS/VSBY DEVELOPING THIS AFTERNOON AND
PERSISTING OVERNIGHT. BECOMING VFR ON MONDAY WITH AREAS OF MVFR
CEILINGS/VSBY IN THE MOUNTAINS.

LONG TERM...WILL LKLY SEE A PERIOD OF IFR AT ALL TERMINALS IN
SNOW TUE NIGHT INTO WED MORNING. KLEB/KCON/KMHT/KPWM ALL COULD SEE
A BRIEF PERIOD OF PL/FZRA LATE TUE NIGHT INTO EARLY WED.
IMPROVEMENT TO VFR EXPECTED WED AFTERNOON THROUGH THU.

&&

.MARINE...
SHORT TERM...NO FLAGS TODAY OR TONIGHT. GALES LIKELY ON MONDAY.

LONG TERM...GALES WILL LINGER INTO MON EVE...BUT SHOULD DIMINISH
DURING THE OVERNIGHT. THESE WINDS WILL BE USHERING ANOTHER ROUND
COLD AIR...AND FREEZING SPRAY IS LIKELY MON NIGHT INTO EARLY TUE.
SCA MAY BE NEEDED TUE NIGHT IN SW FLOW.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.

&&

$$



000
FXUS61 KBOX 011515
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
1015 AM EST SUN MAR 1 2015

.SYNOPSIS...
A FAST MOVING LOW PRESSURE SYSTEM WILL BRING ACCUMULATING SNOW
LATER TODAY AND ESPECIALLY TONIGHT WITH THE HIGHEST AMOUNTS
EXPECTED SOUTH OF THE MASSACHUSETTS TURNPIKE.HIGH PRESSURE BRINGS
DRY COLD AIR FOR THE EARLY WEEK. LOW PRESSURE FROM NORTHERN CANADA
AND ASSOCIATED LOW FORMING OVER THE PLAINS MONDAY WILL
MERGE...THEN PASS WEST AND NORTH OF NEW ENGLAND. THIS WILL SWING A
COLD FRONT ACROSS THE REGION ON WEDNESDAY. DRY AND COLD WEATHER
RETURNS FOR THE END OF THE WEEK.

&&

.NEAR TERM /UNTIL 3 PM THIS AFTERNOON/...

10 AM UPDATE...

FORECAST CONTINUES TO BE MAINLY ON TRACK...MID DECK AND LOWER CLOUDS
WORKING THEIR WAY ACROSS THE AREA WITH PRECIPITAITON GRADUALLY
WORKING ITS WAY THRU THE DRY LAYER BELOW. KBOX RADAR IMAGERY AS OF
15Z SHOWS PRECIP RETURNS AS LOW AS 5-8KFT. 15Z METARS INDICATE LIGHT
SNOW REACHING THE SURFACE IN THE DANBURY CT AREA. CONTINUES TO
LOOK LIKE 15Z-18Z FOR FIRST SNOWFLAKES TO FALL ACROSS WESTERN
ZONES...18Z-20Z EASTERNMOST ZONES. MINOR CHANGES MADE TO HOURLY
TEMPS TO REFLECT LATEST OBS...FORECAST HIGHS LOOK ON TRACK.

EARLY MORNING DISCUSSION...

MID LEVEL CLOUDINESS WILL STREAM INTO SOUTHERN NEW ENGLAND AND
THICKEN DURING THE MORNING HOURS IN ADVANCE OF APPROACHING LOW
PRESSURE.  SOUTHWEST FLOW ALOFT OVERRUNING THE COLD DOME AT THE
SURFACE MAY ALLOW FOR SOME LIGHT SNOW/FLURRIES TO BREAK
OUT ACROSS THE INTERIOR LATE THIS MORNING/EARLY AFTERNOON AND THEN
FIND THEIR WAY TO THE COAST BY MID TO LATE AFTERNOON.  THE LIFT
THROUGH MID AFTERNOON IS FAIRLY WEAK...SO THE AREAS OF SNOW SHOULD
BE RATHER LIGHT. ANY ACCUMULATIONS THAT OCCUR WILL PROBABLY BE
A DUSTING TO LESS THAN 1 INCH THROUGH THAT THAT TIME.  HIGH TEMPS
WILL MAINLY BE IN THE UPPER 20S TO AROUND 30.

&&

.SHORT TERM /3 PM THIS AFTERNOON THROUGH 6 AM MONDAY/...
*** BULK OF THE ACCUMULATING SNOW OCCURS BETWEEN 3 PM AND 1 AM WITH
  THE HEAVIEST AMOUNTS SOUTH OF THE MA TURNPIKE ***

1) OVERVIEW AND TIMING:

THE BULK OF THE ACCUMULATING SNOW WILL OCCUR BETWEEN 3 PM AND
1 AM ACROSS THE REGION.  THE SNOW SHOULD TAPER OFF TO FLURRIES
TOWARD DAYBREAK MONDAY.  THE MODELS DO AGREE THAT THE BETTER FORCING
WILL OCCUR TO THE SOUTH OF THE MA TURNPIKE.  THIS A RESULT
OF SECONDARY LOW PRESSURE NEAR THE SOUTH COAST...ALLOWING FOR
SOME SURFACE CONVERGENCE AS WELL AS THE INTENSIFICATION OF THE LOW
LEVEL JET.

THE BIGGEST ISSUE IS THE MODELS ARE NOT IN AGREEMENT IN HOW
INTENSE THE FORCING WILL BE ACROSS THE REGION THIS EVENING.  THE
RGEM/NAM ARE THE MOST ROBUST WITH QPF SOUTH OF THE MA TURNPIKE.  THE
NAM SHOWS A PERIOD OF FAIRLY STRONG LIFT OF 15 TO 20 MICROBARS PER
SECOND WITHIN THE BEST SNOWGROWTH REGION THIS EVENING.  THIS WOULD
TRANSLATE TO A PERIOD OF 1+ INCH PER HOUR SNOWFALL RATES NEAR AND
SOUTH OF THE MA PIKE.  ON THE OTHER HAND...THE GFS ALSO HAS FAIRLY
STRONG LIFT...BUT KEEPS IT SOUTHEAST OF OUR REGION OUT OVER THE
OCEAN.  THE SECONDARY LOW PRESSURE SYSTEM ON THE GFS IS WEAKER AND
FURTHER SOUTHEAST...RESULTING IN THE LOW LEVEL JET BEING DISPLACED
FURTHER EAST.  THE ECMWF/UKMET SOLUTIONS SEEM TO BE THE MIDDLE
GROUND WHICH WE WILL LEAN TOWARDS.

2) WINTER WEATHER HEADLINES AND SNOW ACCUMS:

WITH THAT SAID...THE OTHER DILEMMA IS WHAT TO DO WITH THE CURRENT
HEADLINES.  THIS DOES NOT APPEAR TO BE THE TYPE OF SETUP WHERE WE
ARE GOING TO RECEIVE WIDESPREAD WARNING SNOWFALL AMOUNTS.  THE
WINDOW FOR THE VERY STRONG LIFT/FORCING IS SHORT-LIVED AND REALLY
WOULD LIKE TO SEE THE LOW LEVEL JET A BIT MORE BACKED TO TRANSPORT
DEEPER MOISTURE NORTHWARD.  THEREFORE...FEEL THAT FOR MOST OF THE
REGION WINTER WEATHER ADVISORY/S FOR 3 TO 6 INCHES OF SNOW WILL
COVER IT.  HOWEVER...GIVEN THERE IS NICE OMEGA IN THE SNOW GROWTH
REGION...WE MIGHT BE LOOKING AT SOME DECENT RATIOS.  SO WE STILL CAN
NOT RULE OUT THE LOW RISK OF REACHING WARNING AMOUNTS AND LATER
SHIFTS WILL HAVE TO MONITOR CLOSELY...ESPECIALLY ACROSS NORTHERN CT
AND NORTHWEST RI.

WE DID UPGRADE A SMALL AREA FROM CENTRAL AND SOUTHERN RHODE ISLAND
INTO SOUTHEAST MA INCLUDING THE SOUTH COAST TO A WINTER
STORM WARNING.  THE NOSE OF THE LOW LEVEL JET LOOKS TO TRANSPORT
SOME DEEPER MOISTURE INTO THIS REGION.  THERE ALSO COULD BE SOME
ENHANCEMENT ALONG THE LAND/SEA INTERFACE AND A WEAK SURFACE
BOUNDARY SO WENT WITH 4 TO 8 INCHES IN THIS REGION.

3) PTYPE AND IMPACTS:

THE MODELS HAVE TRENDED COLDER OVER THE PAST 24 HOURS.
THEREFORE...EXPECT THIS BE PRETTY MUCH A SNOW EVENT.  IT DOES BECOME
A VERY CLOSE CALL NEAR THE SOUTH COAST...BUT WERE LEANING TOWARDS IT
STAYING MAINLY WET SNOW.  IF PRECIPITATION LIGHTENS UP THAT MAY
INCREASE THIS RISK WE SEE A BRIEF CHANGE OVER TO RAIN.
MEANWHILE...WE WENT WITH A HIGH END WINTER WEATHER ADVISORY FOR THE
CAPE BECAUSE THEY MAY CHANGE TO RAIN FOR A TIME...ESPECIALLY EAST OF
HYANNIS.  IF THE CHANGE OVER DOES NOT OCCUR...WE MAY NEED TO UPGRADE
THEM TO A WINTER STORM WARNING ESPECIALLY NEAR THE CAPE COD CANAL
GIVEN EXPECTED QPF.

THE ONE THING WILL ALSO HAVE TO WATCH IS AREAS NEAR THE SOUTH COAST
AND CAPE COD.  LOOKS TO BE A WET SNOW DOWN THAT WAY AND ON GOING
ROOF ISSUES MAY BE EXACERBATED...ESPECIALLY IF ANY AREAS THAT ARE
ABLE TO EXCEED 6 INCHES OF WET SNOW.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
HIGHLIGHTS...

  * BLUSTERY CONDITIONS ON MON WITH DRY WEATHER CONTINUING INTO
    TUE.
  * A STORM SYSTEM BRINGS MIXED PRECIP TUE INTO WED.
  * CONDITIONS IMPROVE THU BUT BECOMING COLD AGAIN.

OVERVIEW AND MODEL PREFERENCES...
A SPLIT FLOW MERGER WILL BE THE DEFINING FACTOR THROUGH THE LONG
TERM FORECAST PERIOD. IN THE MID TERM...THE STREAMS MERGE THANKS
TO PHASING OF NRN AND SRN STREAM SHORTWAVES UPSTREAM AS MERGING
STRONG JET DEVELOPS ACROSS THE NE CONUS. THESE FEATURES WILL ALLOW
LOW PRES TO GRADUALLY DEEPEN AND SLIDE THROUGH SRN ONTARIO AND
QUEBEC...CREATING AN OVERRUNNING EVENT AS THE SYSTEM ATTEMPTS TO
OCCLUDE. THIS IS THE MIXED PRECIP EVENT WE HAVE BEEN DISCUSSING
FOR SOME TIME NOW. NOW THAT NAM HAS CAPTURED IT...IT APPEARS
COLDER THAN MOST OF THE DETERMINISTIC GUIDANCE...WHILE THE ECMWF
STARTS COLD AND SHIFTS TO THE WARMER SIDE OF THE ENVELOPE DUE TO
THE FACT THAT IT IS MORE AMPLIFIED THAN OTHER MODELS. THE
GFS...ECENS/GEFS MEANS ARE ACTUALLY A GOOD MIDDLE GROUND HERE.
THIS BLEND WILL BE USED THROUGH THE REMAINDER OF THE LONG TERM AS
WELL TO TAKE INTO ACCOUNT THE VARIOUS SOLUTIONS.

DETAILS...

MON INTO TUE...
REMNANT SNOWFALLS WILL BE GRADUALLY COMING TO AN END THROUGH MID
MORNING MON...ALTHOUGH FLURRIES MAY LINGER A BIT LONGER IN THE
BERKSHIRES. STRONG HIGH PRES WILL THEN SLIDE ACROSS THE REGION
THROUGH TUE...WITH MAINLY DRY WX. TEMPS LOOK TO REMAIN BELOW
NORMAL GIVEN LITTLE CHANGE IN THE AIRMASS FROM PREVIOUS DAYS.

TUE NIGHT INTO WED...
OVERRUNNING EVENT EXPECTED AS WARM FRONT WILL ATTEMPT TO PUSH N
ACROSS THE REGION BUT IS LIKELY TO STRUGGLE NEAR THE SFC DUE TO
ENTRENCHED COLD AIR AND A DEEP SNOWPACK. HOWEVER...50-60 KT LLJ
WITH STRONG SLY COMPONENT WILL ALLOW UPPER LVL WARMING TON
CONTINUE UNIMPEDED. IN SPITE OF THE STRONG JET AT ONLY 3-5KFT
ABOVE THE SFC...SNOWPACK WILL MAKE MIXING DIFFICULT SO NOT
EXPECTING SIGNIFICANT WIND ISSUES AT THIS TIME.

THE COLUMN STARTS COLD ENOUGH FOR SNOW AT ONSET TUE EVENING...AND
LOOKS LIKE AS MUCH AS 0.40-0.60 OF THE TOTAL EVENT QPF FALLS AS
SNOW INITIALLY EVERYWHERE...WITH GRADUAL CHANGEOVER DURING THE
EARLY MORNING HOURS WED MORNING FROM S-N. THEREFORE...COULD SEE AT
LEAST ADVISORY IF NOT LOW-END WARNING LVL SNOWFALLS THROUGH THE
OVERNIGHT HOURS BEFORE A TRANSITION TO SLEET...THEN FREEZING RAIN.
FREEZING RAIN COULD LOCK IN FOR SOME TIME AND GIVEN THAT H93 TEMPS
/EVEN ON THE COLDEST GUIDANCE/ AN AVERAGE OF +4C DURING THE 08Z-
16Z TIMEFRAME...BUT SFC TEMPS MAY HOLD NEAR FREEZING FOR SOME TIME
GIVEN THE DEEP SNOWPACK ACROSS THE AREA. HOWEVER...STRAIGHT RAIN
FOR A TIME FROM ABOUT MID MORNING INTO THE AFTERNOON IS LIKELY
UNTIL THE PRECIP COMES TO AN END. DEPENDING ON HOW QUICKLY 2M
TEMPS REBOUND...AS MUCH AS A QUARTER INCH OF ICE CAN/T BE RULED
OUT. AGREE WITH PREVIOUS FORECASTER THAT LEANING A BIT COLDER THAN
MOS 2M TEMPS IS PROBABLY THE WAY TO GO.

MODEST UPPER LVL INSTABILITY AS WARMING OCCURS IN THE MID LVLS
COULD ALSO MEAN A PERIOD OF HEAVY PRECIP...BOTH SNOW AND RAIN.
WITH THE RAIN...COMES A RISK FOR POOR DRAINAGE FLOODING ACROSS THE
REGION AS SNOW MELTS AND DRAINS BECOME CLOGGED. PRECIP COMES TO AN
END ACROSS MOST OF THE REGION BY AFTERNOON WED...BUT MAY LINGER A
BIT NEAR THE S COAST...MORE ON THAT BELOW.

WED NIGHT INTO THU...
CONFIDENCE IN THE FORECAST CONTINUES TO DIMINISH HERE PARTIALLY
DEPENDENT ON HOW FAST THE UPPER LVL JET EXITS TO THE EAST AND HOW
AMPLIFIED THE PATTERN REMAINS IN THE WAKE OF THE LOW PRES. THE
MORE AMPLIFIED GUIDANCE...LED BY THE ECMWF KEEPS THE COLD FRONT
JUST OFFSHORE AND WITHIN THE EQUATORWARD ENTRANCE REGION OF THE
UPPER LVL JET. THIS SUGGESTS S COASTAL AREAS COULD CONTINUE TO SEE
PRECIP...POSSIBLY EVEN CHANGING BACK TO SNOW FOR A TIME WELL INTO
THE DAY ON THU. THE MORE PROGRESSIVE GUIDANCE...LED BY THE GFS
WOULD MOVE BOTH OF THESE FEATURES OFFSHORE SUCH THAT THU IS
MAINLY DRY AND BECOMING QUITE COLD AS ANOTHER ARCTIC AIRMASS
SETTLES IN. FOR NOW...WILL CONTINUE TO LEAN ON THE MORE
PROGRESSIVE GFS BUT WITH THE ECENS/GEFS SLOWER MEMBERS BLENDED IN.
THE FINAL ANSWER WILL LIKELY BE SOMEWHERE IN BETWEEN THE TWO
SOLUTIONS. IN ANY CASE...MUCH COLDER AIRMASS EXPECTED TO MOVE IN.

THU NIGHT INTO FRI NIGHT...
COLD AIRMASS ACROSS THE REGION ASSOCIATED WITH YET ANOTHER 1035+
HPA HIGH PRES. WILL LIKELY SEE HIGHS ONLY MAKING THE TEENS AND 20S
WITH LOWS BACK IN THE SINGLE DIGITS ABOVE AND BELOW ZERO.

NEXT WEEKEND...
SOME UNCERTAINTY HERE AS TO WHETHER YET ANOTHER WAVE WILL BE
EFFECT THE REGION. WILL LEAN MAINLY DRY FOR NOW AS THE AIRMASS IN
PLACE IS QUITE DRY AND THE WAVE ITSELF IS QUITE WEAK AND SHEARING
OUT.

&&

.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TODAY AND TONIGHT/...

15Z UPDATE..
THRU MIDDAY TODAY...HIGH CONFIDENCE. MORNING TAFS LOOK ON
TRACK...NO MAJOR CHANGES MADE. FLURRIES SHOULD BEGIN LATE THIS
MORNING BAF/BDL THEN SPREADING W-E. MVFR CONDITIONS POSSIBLE AT
BDL/BAF BY 17Z...TO THE EAST EXPECT VFR THRU 17Z.

THIS AFTERNOON AND TONIGHT...MODERATE CONFIDENCE. MVFR TO POCKETS
OF IFR CONDITIONS DEVELOP FROM WEST TO EAST THIS AFTERNOON IN
AREAS OF LIGHT SNOW. HOWEVER...THE BULK OF THE MODERATE TO EVEN
BRIEFLY HEAVY SNOW WILL OCCUR THIS EVENING WHEN WIDESPREAD IFR TO
LIFR CONDITIONS OCCUR. THE LOWER CONDITIONS MOST LIKELY SOUTH OF
THE MA TURNPIKE. PTYPE PRETTY MUCH ALL SNOW...EXCEPT FOR THE VERY
IMMEDIATE SOUTH COAST/CAPE WHERE SNOW MAY MIX WITH OR CHANGE TO
RAIN FOR A TIME. WHETHER OR NOT THAT HAPPENS IS UNCERTAIN...BUT WE
DO THINK THAT AT LEAST THE ISLANDS WILL CHANGE TO RAIN.

BULK OF SNOW ENDS BY 8 OR 9Z TONIGHT AND MUCH OF THE THE REGION
SHOULD ALREADY HAVE VFR CONDITIONS BY 12Z MONDAY.

KBOS TAF...CONFIDENT IN OVERALL TRENDS BUT EXACT TIMING IS MORE
UNCERTAIN.  WHILE SOME LIGHT SNOW IS POSSIBLE THIS
AFTERNOON...BULK OF ACCUMULATING SNOW WITH WIDESPREAD IFR TO LIFR
CONDITIONS EXPECTED THIS EVENING.

KBDL TAF...CONFIDENT IN OVERALL TRENDS BUT EXACT TIMING IS MORE
UNCERTAIN. SOME LIGHT SNOW IS POSSIBLE LATE THIS
MORNING...LIKELY FOR THIS AFTERNOON. BULK OF ACCUMULATING SNOW
WITH WIDESPREAD IFR TO LIFR CONDITIONS EXPECTED AFTER 3 OR 4 PM.

OUTLOOK...MONDAY THROUGH THURSDAY...

MONDAY...HIGH CONFIDENCE.
IFR/MVFR IN REMNANT SNOWS END EARLY...WITH TRANSITION TO VFR
EVERYWHERE BY AFTERNOON. W-NW WIND GUSTS UP TO AROUND 30 KT AT
TIMES DURING THE AFTERNOON AND EVENING.

MON NIGHT INTO TUE...HIGH CONFIDENCE.
MAINLY VFR. WINDS DIMINISH MON NIGHT.

TUE NIGHT INTO THU...MODERATE CONFIDENCE.
A MESSY PERIOD. SNOW BEGINS EVERYWHERE LATE TUE INTO WED NIGHT
WITH MODERATE ACCUMS POSSIBLE...THEN EXPECT GRADUALLY TRANSITION
TO SLEET AND FREEZING RAIN DURING THE EARLY MORNING HOURS
WED...THEN TO ALL RAIN DURING THE DAY ON WED. SOME ICE ACCUM
POSSIBLE AS WELL. THE RAIN DIMINISHES LATE WED BUT MAY LINGER
ALONG THE S COAST AND EVEN CHANGE TO SNOW INTO THE DAY ON THU.
EXPECT PERIODS OF IFR/LIFR CONDITIONS THROUGHOUT THE PERIOD WITH
SOME IMPROVEMENT FROM N-S ON THU. LLWS LIKELY ESPECIALLY TUE NIGHT
AND EARLY WED.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TODAY AND TONIGHT/...HIGH CONFIDENCE.

A WEAK WAVE OF LOW PRESSURE MOVES ACROSS THE WATERS LATER
TODAY AND TONIGHT.  WEAK PRESSURE GRADIENT SHOULD KEEP
WINDS/SEAS BELOW SMALL CRAFT THRESHOLDS TODAY AND TONIGHT.  THE
SYSTEM REALLY INTENSIFIES AS IT MOVES INTO THE CANADIAN MARITIMES
NEAR DAYBREAK MONDAY...SO WESTERLY WIND GUSTS MAY REACH 20 TO 25
KNOTS NEAR 12Z MONDAY.  OTHERWISE...RAIN AND SNOW LATE TODAY AND
ESPECIALLY TONIGHT WILL REDUCE VISIBILITIES AT TIMES FOR MARINERS.

OUTLOOK...MONDAY THROUGH THURSDAY..MODERATE CONFIDENCE.

MONDAY INTO MONDAY NIGHT...HIGH CONFIDENCE.
WINDS BEGIN OUT OF THE SW THEN SHIFT TO W-NW IN THE AFTERNOON.
WIND GUSTS REACH 35-40 KT DURING THE AFTERNOON AND OVERNIGHT SO
WILL BE ISSUING A GALE WATCH. SEAS BUILD 10-12 FT ON THE OCEAN
WATERS. SOME LIGHT FREEZING SPRAY POSSIBLE MON EVENING INTO TUE
MORNING.

TUE...HIGH CONFIDENCE.
WINDS AND SEAS START AT OR AROUND SMALL CRAFT ADVISORY THRESHOLDS
BUT THEN DROP DURING THE DAY SUCH THAT A PERIOD OF QUIET BOATING
WEATHER IS LIKELY TUE AFTERNOON AND EVENING.

TUE NIGHT INTO THU...MODERATE CONFIDENCE.
LOW PRES PASSES WELL INLAND...WITH WINDS OUT OF THE S GRADUALLY
SHIFTING TO THE W LATE WED INTO THU. PERIODS OF WIND GUSTS 25-30
KT EXPECTED ALTHOUGH GUSTS MAY APPROACH GALE FORCE WED EVENING.
SEAS BUILD THROUGH WED TO AROUND 7-10FT ON THE OCEAN WATERS THEN
DIMINISH THU. AT THE VERY LEAST SMALL CRAFT ADVISORIES ARE LIKELY
DURING THIS PERIOD. PERIODS OF SNOW CHANGING TO RAIN EARLY WED
WITH SOME LOW VSBYS IN RAIN AND FOG ON WED.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR CTZ002>004.
MA...WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR MAZ002>016-
     022>024-026.
     WINTER STORM WARNING FROM 3 PM THIS AFTERNOON TO 7 AM EST
     MONDAY FOR MAZ017>021.
RI...WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR RIZ001-008.
     WINTER STORM WARNING FROM 3 PM THIS AFTERNOON TO 7 AM EST
     MONDAY FOR RIZ002>007.
MARINE...GALE WATCH FROM MONDAY MORNING THROUGH LATE MONDAY NIGHT FOR
     ANZ231>235-237-250-251-254>256.

&&

$$
SYNOPSIS...FRANK/DOODY
NEAR TERM...FRANK/DOODY/NMB
SHORT TERM...FRANK
LONG TERM...DOODY
AVIATION...FRANK/DOODY/NMB
MARINE...FRANK/DOODY



000
FXUS61 KBOX 011515
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
1015 AM EST SUN MAR 1 2015

.SYNOPSIS...
A FAST MOVING LOW PRESSURE SYSTEM WILL BRING ACCUMULATING SNOW
LATER TODAY AND ESPECIALLY TONIGHT WITH THE HIGHEST AMOUNTS
EXPECTED SOUTH OF THE MASSACHUSETTS TURNPIKE.HIGH PRESSURE BRINGS
DRY COLD AIR FOR THE EARLY WEEK. LOW PRESSURE FROM NORTHERN CANADA
AND ASSOCIATED LOW FORMING OVER THE PLAINS MONDAY WILL
MERGE...THEN PASS WEST AND NORTH OF NEW ENGLAND. THIS WILL SWING A
COLD FRONT ACROSS THE REGION ON WEDNESDAY. DRY AND COLD WEATHER
RETURNS FOR THE END OF THE WEEK.

&&

.NEAR TERM /UNTIL 3 PM THIS AFTERNOON/...

10 AM UPDATE...

FORECAST CONTINUES TO BE MAINLY ON TRACK...MID DECK AND LOWER CLOUDS
WORKING THEIR WAY ACROSS THE AREA WITH PRECIPITAITON GRADUALLY
WORKING ITS WAY THRU THE DRY LAYER BELOW. KBOX RADAR IMAGERY AS OF
15Z SHOWS PRECIP RETURNS AS LOW AS 5-8KFT. 15Z METARS INDICATE LIGHT
SNOW REACHING THE SURFACE IN THE DANBURY CT AREA. CONTINUES TO
LOOK LIKE 15Z-18Z FOR FIRST SNOWFLAKES TO FALL ACROSS WESTERN
ZONES...18Z-20Z EASTERNMOST ZONES. MINOR CHANGES MADE TO HOURLY
TEMPS TO REFLECT LATEST OBS...FORECAST HIGHS LOOK ON TRACK.

EARLY MORNING DISCUSSION...

MID LEVEL CLOUDINESS WILL STREAM INTO SOUTHERN NEW ENGLAND AND
THICKEN DURING THE MORNING HOURS IN ADVANCE OF APPROACHING LOW
PRESSURE.  SOUTHWEST FLOW ALOFT OVERRUNING THE COLD DOME AT THE
SURFACE MAY ALLOW FOR SOME LIGHT SNOW/FLURRIES TO BREAK
OUT ACROSS THE INTERIOR LATE THIS MORNING/EARLY AFTERNOON AND THEN
FIND THEIR WAY TO THE COAST BY MID TO LATE AFTERNOON.  THE LIFT
THROUGH MID AFTERNOON IS FAIRLY WEAK...SO THE AREAS OF SNOW SHOULD
BE RATHER LIGHT. ANY ACCUMULATIONS THAT OCCUR WILL PROBABLY BE
A DUSTING TO LESS THAN 1 INCH THROUGH THAT THAT TIME.  HIGH TEMPS
WILL MAINLY BE IN THE UPPER 20S TO AROUND 30.

&&

.SHORT TERM /3 PM THIS AFTERNOON THROUGH 6 AM MONDAY/...
*** BULK OF THE ACCUMULATING SNOW OCCURS BETWEEN 3 PM AND 1 AM WITH
  THE HEAVIEST AMOUNTS SOUTH OF THE MA TURNPIKE ***

1) OVERVIEW AND TIMING:

THE BULK OF THE ACCUMULATING SNOW WILL OCCUR BETWEEN 3 PM AND
1 AM ACROSS THE REGION.  THE SNOW SHOULD TAPER OFF TO FLURRIES
TOWARD DAYBREAK MONDAY.  THE MODELS DO AGREE THAT THE BETTER FORCING
WILL OCCUR TO THE SOUTH OF THE MA TURNPIKE.  THIS A RESULT
OF SECONDARY LOW PRESSURE NEAR THE SOUTH COAST...ALLOWING FOR
SOME SURFACE CONVERGENCE AS WELL AS THE INTENSIFICATION OF THE LOW
LEVEL JET.

THE BIGGEST ISSUE IS THE MODELS ARE NOT IN AGREEMENT IN HOW
INTENSE THE FORCING WILL BE ACROSS THE REGION THIS EVENING.  THE
RGEM/NAM ARE THE MOST ROBUST WITH QPF SOUTH OF THE MA TURNPIKE.  THE
NAM SHOWS A PERIOD OF FAIRLY STRONG LIFT OF 15 TO 20 MICROBARS PER
SECOND WITHIN THE BEST SNOWGROWTH REGION THIS EVENING.  THIS WOULD
TRANSLATE TO A PERIOD OF 1+ INCH PER HOUR SNOWFALL RATES NEAR AND
SOUTH OF THE MA PIKE.  ON THE OTHER HAND...THE GFS ALSO HAS FAIRLY
STRONG LIFT...BUT KEEPS IT SOUTHEAST OF OUR REGION OUT OVER THE
OCEAN.  THE SECONDARY LOW PRESSURE SYSTEM ON THE GFS IS WEAKER AND
FURTHER SOUTHEAST...RESULTING IN THE LOW LEVEL JET BEING DISPLACED
FURTHER EAST.  THE ECMWF/UKMET SOLUTIONS SEEM TO BE THE MIDDLE
GROUND WHICH WE WILL LEAN TOWARDS.

2) WINTER WEATHER HEADLINES AND SNOW ACCUMS:

WITH THAT SAID...THE OTHER DILEMMA IS WHAT TO DO WITH THE CURRENT
HEADLINES.  THIS DOES NOT APPEAR TO BE THE TYPE OF SETUP WHERE WE
ARE GOING TO RECEIVE WIDESPREAD WARNING SNOWFALL AMOUNTS.  THE
WINDOW FOR THE VERY STRONG LIFT/FORCING IS SHORT-LIVED AND REALLY
WOULD LIKE TO SEE THE LOW LEVEL JET A BIT MORE BACKED TO TRANSPORT
DEEPER MOISTURE NORTHWARD.  THEREFORE...FEEL THAT FOR MOST OF THE
REGION WINTER WEATHER ADVISORY/S FOR 3 TO 6 INCHES OF SNOW WILL
COVER IT.  HOWEVER...GIVEN THERE IS NICE OMEGA IN THE SNOW GROWTH
REGION...WE MIGHT BE LOOKING AT SOME DECENT RATIOS.  SO WE STILL CAN
NOT RULE OUT THE LOW RISK OF REACHING WARNING AMOUNTS AND LATER
SHIFTS WILL HAVE TO MONITOR CLOSELY...ESPECIALLY ACROSS NORTHERN CT
AND NORTHWEST RI.

WE DID UPGRADE A SMALL AREA FROM CENTRAL AND SOUTHERN RHODE ISLAND
INTO SOUTHEAST MA INCLUDING THE SOUTH COAST TO A WINTER
STORM WARNING.  THE NOSE OF THE LOW LEVEL JET LOOKS TO TRANSPORT
SOME DEEPER MOISTURE INTO THIS REGION.  THERE ALSO COULD BE SOME
ENHANCEMENT ALONG THE LAND/SEA INTERFACE AND A WEAK SURFACE
BOUNDARY SO WENT WITH 4 TO 8 INCHES IN THIS REGION.

3) PTYPE AND IMPACTS:

THE MODELS HAVE TRENDED COLDER OVER THE PAST 24 HOURS.
THEREFORE...EXPECT THIS BE PRETTY MUCH A SNOW EVENT.  IT DOES BECOME
A VERY CLOSE CALL NEAR THE SOUTH COAST...BUT WERE LEANING TOWARDS IT
STAYING MAINLY WET SNOW.  IF PRECIPITATION LIGHTENS UP THAT MAY
INCREASE THIS RISK WE SEE A BRIEF CHANGE OVER TO RAIN.
MEANWHILE...WE WENT WITH A HIGH END WINTER WEATHER ADVISORY FOR THE
CAPE BECAUSE THEY MAY CHANGE TO RAIN FOR A TIME...ESPECIALLY EAST OF
HYANNIS.  IF THE CHANGE OVER DOES NOT OCCUR...WE MAY NEED TO UPGRADE
THEM TO A WINTER STORM WARNING ESPECIALLY NEAR THE CAPE COD CANAL
GIVEN EXPECTED QPF.

THE ONE THING WILL ALSO HAVE TO WATCH IS AREAS NEAR THE SOUTH COAST
AND CAPE COD.  LOOKS TO BE A WET SNOW DOWN THAT WAY AND ON GOING
ROOF ISSUES MAY BE EXACERBATED...ESPECIALLY IF ANY AREAS THAT ARE
ABLE TO EXCEED 6 INCHES OF WET SNOW.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
HIGHLIGHTS...

  * BLUSTERY CONDITIONS ON MON WITH DRY WEATHER CONTINUING INTO
    TUE.
  * A STORM SYSTEM BRINGS MIXED PRECIP TUE INTO WED.
  * CONDITIONS IMPROVE THU BUT BECOMING COLD AGAIN.

OVERVIEW AND MODEL PREFERENCES...
A SPLIT FLOW MERGER WILL BE THE DEFINING FACTOR THROUGH THE LONG
TERM FORECAST PERIOD. IN THE MID TERM...THE STREAMS MERGE THANKS
TO PHASING OF NRN AND SRN STREAM SHORTWAVES UPSTREAM AS MERGING
STRONG JET DEVELOPS ACROSS THE NE CONUS. THESE FEATURES WILL ALLOW
LOW PRES TO GRADUALLY DEEPEN AND SLIDE THROUGH SRN ONTARIO AND
QUEBEC...CREATING AN OVERRUNNING EVENT AS THE SYSTEM ATTEMPTS TO
OCCLUDE. THIS IS THE MIXED PRECIP EVENT WE HAVE BEEN DISCUSSING
FOR SOME TIME NOW. NOW THAT NAM HAS CAPTURED IT...IT APPEARS
COLDER THAN MOST OF THE DETERMINISTIC GUIDANCE...WHILE THE ECMWF
STARTS COLD AND SHIFTS TO THE WARMER SIDE OF THE ENVELOPE DUE TO
THE FACT THAT IT IS MORE AMPLIFIED THAN OTHER MODELS. THE
GFS...ECENS/GEFS MEANS ARE ACTUALLY A GOOD MIDDLE GROUND HERE.
THIS BLEND WILL BE USED THROUGH THE REMAINDER OF THE LONG TERM AS
WELL TO TAKE INTO ACCOUNT THE VARIOUS SOLUTIONS.

DETAILS...

MON INTO TUE...
REMNANT SNOWFALLS WILL BE GRADUALLY COMING TO AN END THROUGH MID
MORNING MON...ALTHOUGH FLURRIES MAY LINGER A BIT LONGER IN THE
BERKSHIRES. STRONG HIGH PRES WILL THEN SLIDE ACROSS THE REGION
THROUGH TUE...WITH MAINLY DRY WX. TEMPS LOOK TO REMAIN BELOW
NORMAL GIVEN LITTLE CHANGE IN THE AIRMASS FROM PREVIOUS DAYS.

TUE NIGHT INTO WED...
OVERRUNNING EVENT EXPECTED AS WARM FRONT WILL ATTEMPT TO PUSH N
ACROSS THE REGION BUT IS LIKELY TO STRUGGLE NEAR THE SFC DUE TO
ENTRENCHED COLD AIR AND A DEEP SNOWPACK. HOWEVER...50-60 KT LLJ
WITH STRONG SLY COMPONENT WILL ALLOW UPPER LVL WARMING TON
CONTINUE UNIMPEDED. IN SPITE OF THE STRONG JET AT ONLY 3-5KFT
ABOVE THE SFC...SNOWPACK WILL MAKE MIXING DIFFICULT SO NOT
EXPECTING SIGNIFICANT WIND ISSUES AT THIS TIME.

THE COLUMN STARTS COLD ENOUGH FOR SNOW AT ONSET TUE EVENING...AND
LOOKS LIKE AS MUCH AS 0.40-0.60 OF THE TOTAL EVENT QPF FALLS AS
SNOW INITIALLY EVERYWHERE...WITH GRADUAL CHANGEOVER DURING THE
EARLY MORNING HOURS WED MORNING FROM S-N. THEREFORE...COULD SEE AT
LEAST ADVISORY IF NOT LOW-END WARNING LVL SNOWFALLS THROUGH THE
OVERNIGHT HOURS BEFORE A TRANSITION TO SLEET...THEN FREEZING RAIN.
FREEZING RAIN COULD LOCK IN FOR SOME TIME AND GIVEN THAT H93 TEMPS
/EVEN ON THE COLDEST GUIDANCE/ AN AVERAGE OF +4C DURING THE 08Z-
16Z TIMEFRAME...BUT SFC TEMPS MAY HOLD NEAR FREEZING FOR SOME TIME
GIVEN THE DEEP SNOWPACK ACROSS THE AREA. HOWEVER...STRAIGHT RAIN
FOR A TIME FROM ABOUT MID MORNING INTO THE AFTERNOON IS LIKELY
UNTIL THE PRECIP COMES TO AN END. DEPENDING ON HOW QUICKLY 2M
TEMPS REBOUND...AS MUCH AS A QUARTER INCH OF ICE CAN/T BE RULED
OUT. AGREE WITH PREVIOUS FORECASTER THAT LEANING A BIT COLDER THAN
MOS 2M TEMPS IS PROBABLY THE WAY TO GO.

MODEST UPPER LVL INSTABILITY AS WARMING OCCURS IN THE MID LVLS
COULD ALSO MEAN A PERIOD OF HEAVY PRECIP...BOTH SNOW AND RAIN.
WITH THE RAIN...COMES A RISK FOR POOR DRAINAGE FLOODING ACROSS THE
REGION AS SNOW MELTS AND DRAINS BECOME CLOGGED. PRECIP COMES TO AN
END ACROSS MOST OF THE REGION BY AFTERNOON WED...BUT MAY LINGER A
BIT NEAR THE S COAST...MORE ON THAT BELOW.

WED NIGHT INTO THU...
CONFIDENCE IN THE FORECAST CONTINUES TO DIMINISH HERE PARTIALLY
DEPENDENT ON HOW FAST THE UPPER LVL JET EXITS TO THE EAST AND HOW
AMPLIFIED THE PATTERN REMAINS IN THE WAKE OF THE LOW PRES. THE
MORE AMPLIFIED GUIDANCE...LED BY THE ECMWF KEEPS THE COLD FRONT
JUST OFFSHORE AND WITHIN THE EQUATORWARD ENTRANCE REGION OF THE
UPPER LVL JET. THIS SUGGESTS S COASTAL AREAS COULD CONTINUE TO SEE
PRECIP...POSSIBLY EVEN CHANGING BACK TO SNOW FOR A TIME WELL INTO
THE DAY ON THU. THE MORE PROGRESSIVE GUIDANCE...LED BY THE GFS
WOULD MOVE BOTH OF THESE FEATURES OFFSHORE SUCH THAT THU IS
MAINLY DRY AND BECOMING QUITE COLD AS ANOTHER ARCTIC AIRMASS
SETTLES IN. FOR NOW...WILL CONTINUE TO LEAN ON THE MORE
PROGRESSIVE GFS BUT WITH THE ECENS/GEFS SLOWER MEMBERS BLENDED IN.
THE FINAL ANSWER WILL LIKELY BE SOMEWHERE IN BETWEEN THE TWO
SOLUTIONS. IN ANY CASE...MUCH COLDER AIRMASS EXPECTED TO MOVE IN.

THU NIGHT INTO FRI NIGHT...
COLD AIRMASS ACROSS THE REGION ASSOCIATED WITH YET ANOTHER 1035+
HPA HIGH PRES. WILL LIKELY SEE HIGHS ONLY MAKING THE TEENS AND 20S
WITH LOWS BACK IN THE SINGLE DIGITS ABOVE AND BELOW ZERO.

NEXT WEEKEND...
SOME UNCERTAINTY HERE AS TO WHETHER YET ANOTHER WAVE WILL BE
EFFECT THE REGION. WILL LEAN MAINLY DRY FOR NOW AS THE AIRMASS IN
PLACE IS QUITE DRY AND THE WAVE ITSELF IS QUITE WEAK AND SHEARING
OUT.

&&

.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TODAY AND TONIGHT/...

15Z UPDATE..
THRU MIDDAY TODAY...HIGH CONFIDENCE. MORNING TAFS LOOK ON
TRACK...NO MAJOR CHANGES MADE. FLURRIES SHOULD BEGIN LATE THIS
MORNING BAF/BDL THEN SPREADING W-E. MVFR CONDITIONS POSSIBLE AT
BDL/BAF BY 17Z...TO THE EAST EXPECT VFR THRU 17Z.

THIS AFTERNOON AND TONIGHT...MODERATE CONFIDENCE. MVFR TO POCKETS
OF IFR CONDITIONS DEVELOP FROM WEST TO EAST THIS AFTERNOON IN
AREAS OF LIGHT SNOW. HOWEVER...THE BULK OF THE MODERATE TO EVEN
BRIEFLY HEAVY SNOW WILL OCCUR THIS EVENING WHEN WIDESPREAD IFR TO
LIFR CONDITIONS OCCUR. THE LOWER CONDITIONS MOST LIKELY SOUTH OF
THE MA TURNPIKE. PTYPE PRETTY MUCH ALL SNOW...EXCEPT FOR THE VERY
IMMEDIATE SOUTH COAST/CAPE WHERE SNOW MAY MIX WITH OR CHANGE TO
RAIN FOR A TIME. WHETHER OR NOT THAT HAPPENS IS UNCERTAIN...BUT WE
DO THINK THAT AT LEAST THE ISLANDS WILL CHANGE TO RAIN.

BULK OF SNOW ENDS BY 8 OR 9Z TONIGHT AND MUCH OF THE THE REGION
SHOULD ALREADY HAVE VFR CONDITIONS BY 12Z MONDAY.

KBOS TAF...CONFIDENT IN OVERALL TRENDS BUT EXACT TIMING IS MORE
UNCERTAIN.  WHILE SOME LIGHT SNOW IS POSSIBLE THIS
AFTERNOON...BULK OF ACCUMULATING SNOW WITH WIDESPREAD IFR TO LIFR
CONDITIONS EXPECTED THIS EVENING.

KBDL TAF...CONFIDENT IN OVERALL TRENDS BUT EXACT TIMING IS MORE
UNCERTAIN. SOME LIGHT SNOW IS POSSIBLE LATE THIS
MORNING...LIKELY FOR THIS AFTERNOON. BULK OF ACCUMULATING SNOW
WITH WIDESPREAD IFR TO LIFR CONDITIONS EXPECTED AFTER 3 OR 4 PM.

OUTLOOK...MONDAY THROUGH THURSDAY...

MONDAY...HIGH CONFIDENCE.
IFR/MVFR IN REMNANT SNOWS END EARLY...WITH TRANSITION TO VFR
EVERYWHERE BY AFTERNOON. W-NW WIND GUSTS UP TO AROUND 30 KT AT
TIMES DURING THE AFTERNOON AND EVENING.

MON NIGHT INTO TUE...HIGH CONFIDENCE.
MAINLY VFR. WINDS DIMINISH MON NIGHT.

TUE NIGHT INTO THU...MODERATE CONFIDENCE.
A MESSY PERIOD. SNOW BEGINS EVERYWHERE LATE TUE INTO WED NIGHT
WITH MODERATE ACCUMS POSSIBLE...THEN EXPECT GRADUALLY TRANSITION
TO SLEET AND FREEZING RAIN DURING THE EARLY MORNING HOURS
WED...THEN TO ALL RAIN DURING THE DAY ON WED. SOME ICE ACCUM
POSSIBLE AS WELL. THE RAIN DIMINISHES LATE WED BUT MAY LINGER
ALONG THE S COAST AND EVEN CHANGE TO SNOW INTO THE DAY ON THU.
EXPECT PERIODS OF IFR/LIFR CONDITIONS THROUGHOUT THE PERIOD WITH
SOME IMPROVEMENT FROM N-S ON THU. LLWS LIKELY ESPECIALLY TUE NIGHT
AND EARLY WED.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TODAY AND TONIGHT/...HIGH CONFIDENCE.

A WEAK WAVE OF LOW PRESSURE MOVES ACROSS THE WATERS LATER
TODAY AND TONIGHT.  WEAK PRESSURE GRADIENT SHOULD KEEP
WINDS/SEAS BELOW SMALL CRAFT THRESHOLDS TODAY AND TONIGHT.  THE
SYSTEM REALLY INTENSIFIES AS IT MOVES INTO THE CANADIAN MARITIMES
NEAR DAYBREAK MONDAY...SO WESTERLY WIND GUSTS MAY REACH 20 TO 25
KNOTS NEAR 12Z MONDAY.  OTHERWISE...RAIN AND SNOW LATE TODAY AND
ESPECIALLY TONIGHT WILL REDUCE VISIBILITIES AT TIMES FOR MARINERS.

OUTLOOK...MONDAY THROUGH THURSDAY..MODERATE CONFIDENCE.

MONDAY INTO MONDAY NIGHT...HIGH CONFIDENCE.
WINDS BEGIN OUT OF THE SW THEN SHIFT TO W-NW IN THE AFTERNOON.
WIND GUSTS REACH 35-40 KT DURING THE AFTERNOON AND OVERNIGHT SO
WILL BE ISSUING A GALE WATCH. SEAS BUILD 10-12 FT ON THE OCEAN
WATERS. SOME LIGHT FREEZING SPRAY POSSIBLE MON EVENING INTO TUE
MORNING.

TUE...HIGH CONFIDENCE.
WINDS AND SEAS START AT OR AROUND SMALL CRAFT ADVISORY THRESHOLDS
BUT THEN DROP DURING THE DAY SUCH THAT A PERIOD OF QUIET BOATING
WEATHER IS LIKELY TUE AFTERNOON AND EVENING.

TUE NIGHT INTO THU...MODERATE CONFIDENCE.
LOW PRES PASSES WELL INLAND...WITH WINDS OUT OF THE S GRADUALLY
SHIFTING TO THE W LATE WED INTO THU. PERIODS OF WIND GUSTS 25-30
KT EXPECTED ALTHOUGH GUSTS MAY APPROACH GALE FORCE WED EVENING.
SEAS BUILD THROUGH WED TO AROUND 7-10FT ON THE OCEAN WATERS THEN
DIMINISH THU. AT THE VERY LEAST SMALL CRAFT ADVISORIES ARE LIKELY
DURING THIS PERIOD. PERIODS OF SNOW CHANGING TO RAIN EARLY WED
WITH SOME LOW VSBYS IN RAIN AND FOG ON WED.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR CTZ002>004.
MA...WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR MAZ002>016-
     022>024-026.
     WINTER STORM WARNING FROM 3 PM THIS AFTERNOON TO 7 AM EST
     MONDAY FOR MAZ017>021.
RI...WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR RIZ001-008.
     WINTER STORM WARNING FROM 3 PM THIS AFTERNOON TO 7 AM EST
     MONDAY FOR RIZ002>007.
MARINE...GALE WATCH FROM MONDAY MORNING THROUGH LATE MONDAY NIGHT FOR
     ANZ231>235-237-250-251-254>256.

&&

$$
SYNOPSIS...FRANK/DOODY
NEAR TERM...FRANK/DOODY/NMB
SHORT TERM...FRANK
LONG TERM...DOODY
AVIATION...FRANK/DOODY/NMB
MARINE...FRANK/DOODY




000
FXUS61 KGYX 011353
AFDGYX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
853 AM EST SUN MAR 1 2015

.SYNOPSIS...
LOW PRESSURE WILL MOVE IN FROM THE WEST THIS AFTERNOON AND WILL
CROSS THE REGION OVERNIGHT...PRODUCING SOME LIGHT SNOW. A STRONG
NORTHWEST FLOW WILL SET UP IN ITS WAKE ON MONDAY. HIGH PRESSURE
WILL BUILD IN FROM THE WEST MONDAY NIGHT AND WILL CREST OVER THE
REGION EARLY TUESDAY BEFORE MOVING OFFSHORE. LOW PRESSURE WILL
SWING THROUGH SOUTHERN CANADA TUESDAY NIGHT PUSHING A WARM NORTH
ACROSS THE REGION...AND PRODUCING A PERIOD OF SNOW...SLEET...OR
FREEZING RAIN. AS THE LOW SHIFT TO OUT NORTH...IT WILL DRAG A COLD
FRONT THROUGH THE REGION ON WEDNESDAY. HIGH PRESSURE WILL BUILD IN
FROM THE WEST THURSDAY AND WILL CREST OVER THE REGION ON FRIDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
UPDATE...
HAVE UPDATED GRIDS BASED ON CURRENT OBSERVATIONS AND TRENDS.

SNOW CONTINUES TO PROGRESS EAST...HOWEVER MUCH OF THIS IS
INITIALLY DRYING UP WITH VERY DRY INITIAL CONDITIONS IN MAINE AND
NEW HAMPSHIRE WITH DEW POINTS STILL BELOW ZERO. SNOW WILL ENTER
SOUTHWEST NEW HAMPSHIRE DURING THE EARLY TO MID AFTERNOON HOURS
BEFORE SPREADING EAST.

PREV DISC...
CLOUDS WILL INCREASE AND THICKEN ACROSS THE REGION
THIS MORNING THROUGH MID AFTERNOON AS WEAK LOW PRESSURE PUSHES IN
FROM THE WEST. WILL SEE LIGHT SNOW BREAKING OUT IN NEW HAMPSHIRE
DURING THE MID TO LATE AFTERNOON AND THIS WILL PUSH EAST INTO
WESTERN MAINE THROUGH EARLY EVENING. ONLY LOOKING AT ACCUMULATIONS
OF AN INCH OR LESS THROUGH THE END OF THE DAY WITH MOST OF THAT IN
SOUTHERN NEW HAMPSHIRE. ONCE AGAIN TEMPERATURES WILL REMAIN BELOW
NORMAL WITH HIGH GENERALLY RANGING THROUGH THE 20S.

&&

.SHORT TERM /MONDAY/...
LIGHT SNOW WILL CONTINUE OVERNIGHT THROUGHOUT THE FORECAST AREA AS
LOW PRESSURE PUSHES THROUGH THE REGION. STORM TOTALS FOR MUCH OF
THE FORECAST AREA WILL BE IN THE 1 TO 3 INCH RANGE ALTHOUGH
SOUTHERN NEW HAMPSHIRE MAY SEE LOCALLY HIGHER AMOUNTS OF 2 TO 4
INCHES. LOWS TEMPS WILL BOTTOM OUT IN THE TEENS NORTH AND 20S
SOUTH.

TRAILING COLD FRONT WILL CROSS THE REGION MONDAY MORNING AS LOW
PRESSURE SHIFTS INTO THE MARITIMES. EXPECT ANY LINGERING SNOW
SHOWERS TO END BY LATE MORNING DOWNWIND OF THE MOUNTAINS WITH
PARTIAL CLEARING IN THE AFTERNOON AS STRONG NORTHWEST FLOW SETS UP
BEHIND THE FRONT. INCREASING UPSLOPE FLOW AND LOW LEVEL MOISTURE WILL
KEEP SNOW SHOWERS GOING IN THE MOUNTAINS. EXPECT HIGH TEMPS TO BE
REACHED IN THE MORNING BEFORE DROPPING BACK IN THE AFTERNOON.
HIGHS WILL RANGE FROM THE MID 20S TO LOWER 30S NORTH AND LOWER TO
MID 30S SOUTH.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
MODELS CONTINUE SUGGEST CHANGES TO THE NRN HEMISPHERE 500 MB
PATTERN....WITH SHORTER WAVELENGTHS IN THE FLOW...AND LESS
ESTABLISHED BLOCKING. THIS WILL GENERALLY MAKE FOR A MORE
PROGRESSIVE PATTERN...AND MAY ALLOW SOME WARMER AIR TO BEGIN TO
NUDGE POLEWARD. THE PROGRESSIVE PATTERN WILL ALSO LIMIT THE
DEVELOPMENT OF ANY SIGNIFICANT ERN CONUS STORMS.

MON EVE STARTS OFF WITH GUSTY NW FLOW AND SOME MN SHSN...BUT THE
WINDS AND SHSN WILL BEGIN TO DIMINISH BEFORE MIDNIGHT...AND
CONTINUE TO DO SO OVERNIGHT. SOME LATE RAD COOLING WILL ALLOW
TEMPS TO FALL TO AROUND ZERO IN THE NORTH...AND AROUND 10 ABOVE
ALONG THE COAST /WHICH COMPARED TO RECENTLY IS NOT AS COLD...BUT
STILL ABOUT 10 DEGREES BLO NORMAL/. TUE WILL START OFF SUNNY...BUT
INCREASING MID-HIGH CLOUDS OVERSPREAD THE REGION FROM SW-NE...WITH
AN CHANCE FOR SOME LIGHT SN IN SW NH LATE IN THE
AFTERNOON...ALTHOUGH IN GENERALLY THE PRECIP WILL HOLD OFF UNTIL
TUE NIGHT.

TUE NIGHT WILL SEE MAINLY WAA PRECIP STARTING OFF AS SNOW
CONTINUING THROUGH THE EVENING AND INTO THE EVENING. BY THE PRE-
DAWN HOURS WILL START TO ABV FREEZING AIR WORKING ALOFT...MAINLY
ACROSS THE SRN HALF OF NH AND SW ME....AND COULD SEE PRECIP CHANGE
OVER TO PL/FZRA FOR A TIME. HOWEVER...BULK OF THE OVERNIGHT WILL
BE SNOW...AND SEVERAL INCHES ARE POSSIBLE BEFORE ANY CHANGE IN THE
S AND W ZONES...AS WELL AS THE REST OF THE CWA WHERE SNOW
CONTINUES THRU THE NIGHT. OVERALL QPF ARE RUNNING 0.25-0.5" ATTM.
GENERALLY THE MODELS ARE MORE PROGRESSIVE WITH THIS FIRST WAVE AND
PRECIP MOVES OUT WED MORNING...ALTHOUGH IT COULD END AS A A
LITTLE FZRA OR JUST PLAIN RAIN ON THE COAST AND IN SRN NH AS TEMPS
WILL BE RISING THRU THE TUE NIGHT AND ON WED....WHEN HIGHS COULD
TOP AROUND 40 IN MANY SPOTS.

MODEL CONSENSUS WOULD KEEP THE WEAK COLD FRONT THAT MOVES THRU
LATE WED STALLED WELL TO OUR S...AND HAVE LITTLE IMPACT ON THE
AREA THU. HOWEVER...THE HEMI CMC LIFTS IT BACK FAR ENOUGH N TO
POSSIBLY BRUSH THE COAST WITH A LITTLE PRECIP...AND THE CMC HAS
BEEN PERFORMING WELL THIS WINTER...SO SOMETHING TO KEEP AN EYE ON
FOR NOW. EITHER WAY...THE KICKER TROUGH MOVES THROUGH ON THU AND
IT TURNS COLDER AGAIN FOR FRI AND SAT...ALTHOUGH HIGHS WILL GET
INTO THE 20S TO AROUND 30 FRI/SAT...THIS IS STILL 10 DEGREES OR
SO BLO NORMAL.

&&

.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
SHORT TERM...MVFR/IFR CEILINGS/VSBY DEVELOPING THIS AFTERNOON AND
PERSISTING OVERNIGHT. BECOMING VFR ON MONDAY WITH AREAS OF MVFR
CEILINGS/VSBY IN THE MOUNTAINS.

LONG TERM...WILL LKLY SEE A PERIOD OF IFR AT ALL TERMINALS IN
SNOW TUE NIGHT INTO WED MORNING. KLEB/KCON/KMHT/KPWM ALL COULD SEE
A BRIEF PERIOD OF PL/FZRA LATE TUE NIGHT INTO EARLY WED.
IMPROVEMENT TO VFR EXPECTED WED AFTERNOON THROUGH THU.

&&

.MARINE...
SHORT TERM...NO FLAGS TODAY OR TONIGHT. GALES LIKELY ON MONDAY.

LONG TERM...GALES WILL LINGER INTO MON EVE...BUT SHOULD DIMINISH
DURING THE OVERNIGHT. THESE WINDS WILL BE USHERING ANOTHER ROUND
COLD AIR...AND FREEZING SPRAY IS LIKELY MON NIGHT INTO EARLY TUE.
SCA MAY BE NEEDED TUE NIGHT IN SW FLOW.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.

&&

$$



000
FXUS61 KBOX 011206
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
706 AM EST SUN MAR 1 2015

.SYNOPSIS...
A FAST MOVING LOW PRESSURE SYSTEM WILL BRING ACCUMULATING SNOW
LATER TODAY AND ESPECIALLY TONIGHT WITH THE HIGHEST AMOUNTS
EXPECTED SOUTH OF THE MASSACHUSETTS TURNPIKE.HIGH PRESSURE BRINGS
DRY COLD AIR FOR THE EARLY WEEK. LOW PRESSURE FROM NORTHERN CANADA
AND ASSOCIATED LOW FORMING OVER THE PLAINS MONDAY WILL
MERGE...THEN PASS WEST AND NORTH OF NEW ENGLAND. THIS WILL SWING A
COLD FRONT ACROSS THE REGION ON WEDNESDAY. DRY AND COLD WEATHER
RETURNS FOR THE END OF THE WEEK.

&&

.NEAR TERM /UNTIL 3 PM THIS AFTERNOON/...
7 AM UPDATE...
FORECAST THIS MORNING IS MAINLY ON TRACK. ADDED A BIT MORE HIGH
CLOUDS AND SPED UP TIMING OF FLURRIES IN THE W AS RETURNS ARE
ALREADY VISIBLE ABOVE 10KFT ON KBOX. IT WILL TAKE SOME TIME FOR
THESE TO START REACHING THE GROUND THOUGH...BECAUSE DWPT
DEPRESSIONS ARE STILL 10F OR MORE ACROSS THE REGION WITH ACTUAL
DWPTS MAINLY IN THE NEGATIVE SINGLE DIGITS.

PREVIOUS DISCUSSION...

MID LEVEL CLOUDINESS WILL STREAM INTO SOUTHERN NEW ENGLAND AND
THICKEN DURING THE MORNING HOURS IN ADVANCE OF APPROACHING LOW
PRESSURE.  SOUTHWEST FLOW ALOFT OVERRUNING THE COLD DOME AT THE
SURFACE MAY ALLOW FOR SOME LIGHT SNOW/FLURRIES TO BREAK
OUT ACROSS THE INTERIOR LATE THIS MORNING/EARLY AFTERNOON AND THEN
FIND THEIR WAY TO THE COAST BY MID TO LATE AFTERNOON.  THE LIFT
THROUGH MID AFTERNOON IS FAIRLY WEAK...SO THE AREAS OF SNOW SHOULD
BE RATHER LIGHT. ANY ACCUMULATIONS THAT OCCUR WILL PROBABLY BE
A DUSTING TO LESS THAN 1 INCH THROUGH THAT THAT TIME.  HIGH TEMPS
WILL MAINLY BE IN THE UPPER 20S TO AROUND 30.

&&

.SHORT TERM /3 PM THIS AFTERNOON THROUGH 6 AM MONDAY/...
*** BULK OF THE ACCUMULATING SNOW OCCURS BETWEEN 3 PM AND 1 AM WITH
  THE HEAVIEST AMOUNTS SOUTH OF THE MA TURNPIKE ***

1) OVERVIEW AND TIMING:

THE BULK OF THE ACCUMULATING SNOW WILL OCCUR BETWEEN 3 PM AND
1 AM ACROSS THE REGION.  THE SNOW SHOULD TAPER OFF TO FLURRIES
TOWARD DAYBREAK MONDAY.  THE MODELS DO AGREE THAT THE BETTER FORCING
WILL OCCUR TO THE SOUTH OF THE MA TURNPIKE.  THIS A RESULT
OF SECONDARY LOW PRESSURE NEAR THE SOUTH COAST...ALLOWING FOR
SOME SURFACE CONVERGENCE AS WELL AS THE INTENSIFICATION OF THE LOW
LEVEL JET.

THE BIGGEST ISSUE IS THE MODELS ARE NOT IN AGREEMENT IN HOW
INTENSE THE FORCING WILL BE ACROSS THE REGION THIS EVENING.  THE
RGEM/NAM ARE THE MOST ROBUST WITH QPF SOUTH OF THE MA TURNPIKE.  THE
NAM SHOWS A PERIOD OF FAIRLY STRONG LIFT OF 15 TO 20 MICROBARS PER
SECOND WITHIN THE BEST SNOWGROWTH REGION THIS EVENING.  THIS WOULD
TRANSLATE TO A PERIOD OF 1+ INCH PER HOUR SNOWFALL RATES NEAR AND
SOUTH OF THE MA PIKE.  ON THE OTHER HAND...THE GFS ALSO HAS FAIRLY
STRONG LIFT...BUT KEEPS IT SOUTHEAST OF OUR REGION OUT OVER THE
OCEAN.  THE SECONDARY LOW PRESSURE SYSTEM ON THE GFS IS WEAKER AND
FURTHER SOUTHEAST...RESULTING IN THE LOW LEVEL JET BEING DISPLACED
FURTHER EAST.  THE ECMWF/UKMET SOLUTIONS SEEM TO BE THE MIDDLE
GROUND WHICH WE WILL LEAN TOWARDS.

2) WINTER WEATHER HEADLINES AND SNOW ACCUMS:

WITH THAT SAID...THE OTHER DILEMMA IS WHAT TO DO WITH THE CURRENT
HEADLINES.  THIS DOES NOT APPEAR TO BE THE TYPE OF SETUP WHERE WE
ARE GOING TO RECEIVE WIDESPREAD WARNING SNOWFALL AMOUNTS.  THE
WINDOW FOR THE VERY STRONG LIFT/FORCING IS SHORT-LIVED AND REALLY
WOULD LIKE TO SEE THE LOW LEVEL JET A BIT MORE BACKED TO TRANSPORT
DEEPER MOISTURE NORTHWARD.  THEREFORE...FEEL THAT FOR MOST OF THE
REGION WINTER WEATHER ADVISORY/S FOR 3 TO 6 INCHES OF SNOW WILL
COVER IT.  HOWEVER...GIVEN THERE IS NICE OMEGA IN THE SNOW GROWTH
REGION...WE MIGHT BE LOOKING AT SOME DECENT RATIOS.  SO WE STILL CAN
NOT RULE OUT THE LOW RISK OF REACHING WARNING AMOUNTS AND LATER
SHIFTS WILL HAVE TO MONITOR CLOSELY...ESPECIALLY ACROSS NORTHERN CT
AND NORTHWEST RI.

WE DID UPGRADE A SMALL AREA FROM CENTRAL AND SOUTHERN RHODE ISLAND
INTO SOUTHEAST MA INCLUDING THE SOUTH COAST TO A WINTER
STORM WARNING.  THE NOSE OF THE LOW LEVEL JET LOOKS TO TRANSPORT
SOME DEEPER MOISTURE INTO THIS REGION.  THERE ALSO COULD BE SOME
ENHANCEMENT ALONG THE LAND/SEA INTERFACE AND A WEAK SURFACE
BOUNDARY SO WENT WITH 4 TO 8 INCHES IN THIS REGION.

3) PTYPE AND IMPACTS:

THE MODELS HAVE TRENDED COLDER OVER THE PAST 24 HOURS.
THEREFORE...EXPECT THIS BE PRETTY MUCH A SNOW EVENT.  IT DOES BECOME
A VERY CLOSE CALL NEAR THE SOUTH COAST...BUT WERE LEANING TOWARDS IT
STAYING MAINLY WET SNOW.  IF PRECIPITATION LIGHTENS UP THAT MAY
INCREASE THIS RISK WE SEE A BRIEF CHANGE OVER TO RAIN.
MEANWHILE...WE WENT WITH A HIGH END WINTER WEATHER ADVISORY FOR THE
CAPE BECAUSE THEY MAY CHANGE TO RAIN FOR A TIME...ESPECIALLY EAST OF
HYANNIS.  IF THE CHANGE OVER DOES NOT OCCUR...WE MAY NEED TO UPGRADE
THEM TO A WINTER STORM WARNING ESPECIALLY NEAR THE CAPE COD CANAL
GIVEN EXPECTED QPF.

THE ONE THING WILL ALSO HAVE TO WATCH IS AREAS NEAR THE SOUTH COAST
AND CAPE COD.  LOOKS TO BE A WET SNOW DOWN THAT WAY AND ON GOING
ROOF ISSUES MAY BE EXACERBATED...ESPECIALLY IF ANY AREAS THAT ARE
ABLE TO EXCEED 6 INCHES OF WET SNOW.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
HIGHLIGHTS...

  * BLUSTERY CONDITIONS ON MON WITH DRY WEATHER CONTINUING INTO
    TUE.
  * A STORM SYSTEM BRINGS MIXED PRECIP TUE INTO WED.
  * CONDITIONS IMPROVE THU BUT BECOMING COLD AGAIN.

OVERVIEW AND MODEL PREFERENCES...
A SPLIT FLOW MERGER WILL BE THE DEFINING FACTOR THROUGH THE LONG
TERM FORECAST PERIOD. IN THE MID TERM...THE STREAMS MERGE THANKS
TO PHASING OF NRN AND SRN STREAM SHORTWAVES UPSTREAM AS MERGING
STRONG JET DEVELOPS ACROSS THE NE CONUS. THESE FEATURES WILL ALLOW
LOW PRES TO GRADUALLY DEEPEN AND SLIDE THROUGH SRN ONTARIO AND
QUEBEC...CREATING AN OVERRUNNING EVENT AS THE SYSTEM ATTEMPTS TO
OCCLUDE. THIS IS THE MIXED PRECIP EVENT WE HAVE BEEN DISCUSSING
FOR SOME TIME NOW. NOW THAT NAM HAS CAPTURED IT...IT APPEARS
COLDER THAN MOST OF THE DETERMINISTIC GUIDANCE...WHILE THE ECMWF
STARTS COLD AND SHIFTS TO THE WARMER SIDE OF THE ENVELOPE DUE TO
THE FACT THAT IT IS MORE AMPLIFIED THAN OTHER MODELS. THE
GFS...ECENS/GEFS MEANS ARE ACTUALLY A GOOD MIDDLE GROUND HERE.
THIS BLEND WILL BE USED THROUGH THE REMAINDER OF THE LONG TERM AS
WELL TO TAKE INTO ACCOUNT THE VARIOUS SOLUTIONS.

DETAILS...

MON INTO TUE...
REMNANT SNOWFALLS WILL BE GRADUALLY COMING TO AN END THROUGH MID
MORNING MON...ALTHOUGH FLURRIES MAY LINGER A BIT LONGER IN THE
BERKSHIRES. STRONG HIGH PRES WILL THEN SLIDE ACROSS THE REGION
THROUGH TUE...WITH MAINLY DRY WX. TEMPS LOOK TO REMAIN BELOW
NORMAL GIVEN LITTLE CHANGE IN THE AIRMASS FROM PREVIOUS DAYS.

TUE NIGHT INTO WED...
OVERRUNNING EVENT EXPECTED AS WARM FRONT WILL ATTEMPT TO PUSH N
ACROSS THE REGION BUT IS LIKELY TO STRUGGLE NEAR THE SFC DUE TO
ENTRENCHED COLD AIR AND A DEEP SNOWPACK. HOWEVER...50-60 KT LLJ
WITH STRONG SLY COMPONENT WILL ALLOW UPPER LVL WARMING TON
CONTINUE UNIMPEDED. IN SPITE OF THE STRONG JET AT ONLY 3-5KFT
ABOVE THE SFC...SNOWPACK WILL MAKE MIXING DIFFICULT SO NOT
EXPECTING SIGNIFICANT WIND ISSUES AT THIS TIME.

THE COLUMN STARTS COLD ENOUGH FOR SNOW AT ONSET TUE EVENING...AND
LOOKS LIKE AS MUCH AS 0.40-0.60 OF THE TOTAL EVENT QPF FALLS AS
SNOW INITIALLY EVERYWHERE...WITH GRADUAL CHANGEOVER DURING THE
EARLY MORNING HOURS WED MORNING FROM S-N. THEREFORE...COULD SEE AT
LEAST ADVISORY IF NOT LOW-END WARNING LVL SNOWFALLS THROUGH THE
OVERNIGHT HOURS BEFORE A TRANSITION TO SLEET...THEN FREEZING RAIN.
FREEZING RAIN COULD LOCK IN FOR SOME TIME AND GIVEN THAT H93 TEMPS
/EVEN ON THE COLDEST GUIDANCE/ AN AVERAGE OF +4C DURING THE 08Z-
16Z TIMEFRAME...BUT SFC TEMPS MAY HOLD NEAR FREEZING FOR SOME TIME
GIVEN THE DEEP SNOWPACK ACROSS THE AREA. HOWEVER...STRAIGHT RAIN
FOR A TIME FROM ABOUT MID MORNING INTO THE AFTERNOON IS LIKELY
UNTIL THE PRECIP COMES TO AN END. DEPENDING ON HOW QUICKLY 2M
TEMPS REBOUND...AS MUCH AS A QUARTER INCH OF ICE CAN/T BE RULED
OUT. AGREE WITH PREVIOUS FORECASTER THAT LEANING A BIT COLDER THAN
MOS 2M TEMPS IS PROBABLY THE WAY TO GO.

MODEST UPPER LVL INSTABILITY AS WARMING OCCURS IN THE MID LVLS
COULD ALSO MEAN A PERIOD OF HEAVY PRECIP...BOTH SNOW AND RAIN.
WITH THE RAIN...COMES A RISK FOR POOR DRAINAGE FLOODING ACROSS THE
REGION AS SNOW MELTS AND DRAINS BECOME CLOGGED. PRECIP COMES TO AN
END ACROSS MOST OF THE REGION BY AFTERNOON WED...BUT MAY LINGER A
BIT NEAR THE S COAST...MORE ON THAT BELOW.

WED NIGHT INTO THU...
CONFIDENCE IN THE FORECAST CONTINUES TO DIMINISH HERE PARTIALLY
DEPENDENT ON HOW FAST THE UPPER LVL JET EXITS TO THE EAST AND HOW
AMPLIFIED THE PATTERN REMAINS IN THE WAKE OF THE LOW PRES. THE
MORE AMPLIFIED GUIDANCE...LED BY THE ECMWF KEEPS THE COLD FRONT
JUST OFFSHORE AND WITHIN THE EQUATORWARD ENTRANCE REGION OF THE
UPPER LVL JET. THIS SUGGESTS S COASTAL AREAS COULD CONTINUE TO SEE
PRECIP...POSSIBLY EVEN CHANGING BACK TO SNOW FOR A TIME WELL INTO
THE DAY ON THU. THE MORE PROGRESSIVE GUIDANCE...LED BY THE GFS
WOULD MOVE BOTH OF THESE FEATURES OFFSHORE SUCH THAT THU IS
MAINLY DRY AND BECOMING QUITE COLD AS ANOTHER ARCTIC AIRMASS
SETTLES IN. FOR NOW...WILL CONTINUE TO LEAN ON THE MORE
PROGRESSIVE GFS BUT WITH THE ECENS/GEFS SLOWER MEMBERS BLENDED IN.
THE FINAL ANSWER WILL LIKELY BE SOMEWHERE IN BETWEEN THE TWO
SOLUTIONS. IN ANY CASE...MUCH COLDER AIRMASS EXPECTED TO MOVE IN.

THU NIGHT INTO FRI NIGHT...
COLD AIRMASS ACROSS THE REGION ASSOCIATED WITH YET ANOTHER 1035+
HPA HIGH PRES. WILL LIKELY SEE HIGHS ONLY MAKING THE TEENS AND 20S
WITH LOWS BACK IN THE SINGLE DIGITS ABOVE AND BELOW ZERO.

NEXT WEEKEND...
SOME UNCERTAINTY HERE AS TO WHETHER YET ANOTHER WAVE WILL BE
EFFECT THE REGION. WILL LEAN MAINLY DRY FOR NOW AS THE AIRMASS IN
PLACE IS QUITE DRY AND THE WAVE ITSELF IS QUITE WEAK AND SHEARING
OUT.

&&

.AVIATION /11Z SUNDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TODAY AND TONIGHT/...

12Z UPDATE...
NO MAJOR CHANGES TO THE TAFS...IT LOOKS LIKE FLURRIES MAY BEGIN
LATE THIS MORNING FROM W-E BUT WITH MAINLY VFR CONDITIONS. NOT
EXPECTING WIDESPREAD MVFR OR IFR UNTIL AFTER 18Z...SPREADING EAST
FROM THERE.

TODAY AND TONIGHT...MODERATE CONFIDENCE.
VFR CONDITIONS THROUGH AT LEAST MID MORNING. SOME MVFR TO IFR
CONDITIONS DEVELOP FROM WEST TO EAST LATE THIS MORNING AND THIS
AFTERNOON IN AREAS OF LIGHT SNOW. HOWEVER...THE BULK OF THE
MODERATE TO EVEN BRIEFLY HEAVY SNOW WILL OCCUR THIS EVENING WHEN
WIDESPREAD IFR TO LIFR CONDITIONS OCCUR. THE LOWER CONDITIONS MOST
LIKELY SOUTH OF THE MA TURNPIKE. PTYPE PRETTY MUCH ALL
SNOW...EXCEPT FOR THE VERY IMMEDIATE SOUTH COAST/CAPE WHERE SNOW
MAY MIX WITH OR CHANGE TO RAIN FOR A TIME. WHETHER OR NOT THAT
HAPPENS IS UNCERTAIN...BUT WE DO THINK THAT AT LEAST THE ISLANDS
WILL CHANGE TO RAIN.

BULK OF SNOW ENDS BY 8 OR 9Z TONIGHT AND MUCH OF THE THE REGION
SHOULD ALREADY HAVE VFR CONDITIONS BY 12Z MONDAY.

KBOS TAF...CONFIDENT IN OVERALL TRENDS BUT EXACT TIMING IS MORE
UNCERTAIN.  WHILE SOME LIGHT SNOW IS POSSIBLE THIS
AFTERNOON...BULK OF ACCUMULATING SNOW WITH WIDESPREAD IFR TO LIFR
CONDITIONS EXPECTED THIS EVENING.

KBDL TAF...CONFIDENT IN OVERALL TRENDS BUT EXACT TIMING IS MORE
UNCERTAIN.  WHILE SOME LIGHT SNOW IS POSSIBLE LATE THIS MORNING AND
AFTERNOON...BULK OF ACCUMULATING SNOW WITH WIDESPREAD IFR TO LIFR
CONDITIONS EXPECTED AFTER 3 OR 4 PM.

OUTLOOK...MONDAY THROUGH THURSDAY...

MONDAY...HIGH CONFIDENCE.
IFR/MVFR IN REMNANT SNOWS END EARLY...WITH TRANSITION TO VFR
EVERYWHERE BY AFTERNOON. W-NW WIND GUSTS UP TO AROUND 30 KT AT
TIMES DURING THE AFTERNOON AND EVENING.

MON NIGHT INTO TUE...HIGH CONFIDENCE.
MAINLY VFR. WINDS DIMINISH MON NIGHT.

TUE NIGHT INTO THU...MODERATE CONFIDENCE.
A MESSY PERIOD. SNOW BEGINS EVERYWHERE LATE TUE INTO WED NIGHT
WITH MODERATE ACCUMS POSSIBLE...THEN EXPECT GRADUALLY TRANSITION
TO SLEET AND FREEZING RAIN DURING THE EARLY MORNING HOURS
WED...THEN TO ALL RAIN DURING THE DAY ON WED. SOME ICE ACCUM
POSSIBLE AS WELL. THE RAIN DIMINISHES LATE WED BUT MAY LINGER
ALONG THE S COAST AND EVEN CHANGE TO SNOW INTO THE DAY ON THU.
EXPECT PERIODS OF IFR/LIFR CONDITIONS THROUGHOUT THE PERIOD WITH
SOME IMPROVEMENT FROM N-S ON THU. LLWS LIKELY ESPECIALLY TUE NIGHT
AND EARLY WED.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TODAY AND TONIGHT/...HIGH CONFIDENCE.

A WEAK WAVE OF LOW PRESSURE MOVES ACROSS THE WATERS LATER
TODAY AND TONIGHT.  WEAK PRESSURE GRADIENT SHOULD KEEP
WINDS/SEAS BELOW SMALL CRAFT THRESHOLDS TODAY AND TONIGHT.  THE
SYSTEM REALLY INTENSIFIES AS IT MOVES INTO THE CANADIAN MARITIMES
NEAR DAYBREAK MONDAY...SO WESTERLY WIND GUSTS MAY REACH 20 TO 25
KNOTS NEAR 12Z MONDAY.  OTHERWISE...RAIN AND SNOW LATE TODAY AND
ESPECIALLY TONIGHT WILL REDUCE VISIBILITIES AT TIMES FOR MARINERS.

OUTLOOK...MONDAY THROUGH THURSDAY..MODERATE CONFIDENCE.

MONDAY INTO MONDAY NIGHT...HIGH CONFIDENCE.
WINDS BEGIN OUT OF THE SW THEN SHIFT TO W-NW IN THE AFTERNOON.
WIND GUSTS REACH 35-40 KT DURING THE AFTERNOON AND OVERNIGHT SO
WILL BE ISSUING A GALE WATCH. SEAS BUILD 10-12 FT ON THE OCEAN
WATERS. SOME LIGHT FREEZING SPRAY POSSIBLE MON EVENING INTO TUE
MORNING.

TUE...HIGH CONFIDENCE.
WINDS AND SEAS START AT OR AROUND SMALL CRAFT ADVISORY THRESHOLDS
BUT THEN DROP DURING THE DAY SUCH THAT A PERIOD OF QUIET BOATING
WEATHER IS LIKELY TUE AFTERNOON AND EVENING.

TUE NIGHT INTO THU...MODERATE CONFIDENCE.
LOW PRES PASSES WELL INLAND...WITH WINDS OUT OF THE S GRADUALLY
SHIFTING TO THE W LATE WED INTO THU. PERIODS OF WIND GUSTS 25-30
KT EXPECTED ALTHOUGH GUSTS MAY APPROACH GALE FORCE WED EVENING.
SEAS BUILD THROUGH WED TO AROUND 7-10FT ON THE OCEAN WATERS THEN
DIMINISH THU. AT THE VERY LEAST SMALL CRAFT ADVISORIES ARE LIKELY
DURING THIS PERIOD. PERIODS OF SNOW CHANGING TO RAIN EARLY WED
WITH SOME LOW VSBYS IN RAIN AND FOG ON WED.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WINTER WEATHER ADVISORY FROM NOON TODAY TO 7 AM EST MONDAY FOR
     CTZ002>004.
MA...WINTER WEATHER ADVISORY FROM NOON TODAY TO 7 AM EST MONDAY FOR
     MAZ002>016-022>024-026.
     WINTER STORM WARNING FROM 3 PM THIS AFTERNOON TO 7 AM EST
     MONDAY FOR MAZ017>021.
RI...WINTER WEATHER ADVISORY FROM NOON TODAY TO 7 AM EST MONDAY FOR
     RIZ001-008.
     WINTER STORM WARNING FROM 3 PM THIS AFTERNOON TO 7 AM EST
     MONDAY FOR RIZ002>007.
MARINE...GALE WATCH FROM MONDAY MORNING THROUGH LATE MONDAY NIGHT FOR
     ANZ231>235-237-250-251-254>256.

&&

$$
SYNOPSIS...FRANK/DOODY
NEAR TERM...FRANK/DOODY
SHORT TERM...FRANK
LONG TERM...DOODY
AVIATION...FRANK/DOODY
MARINE...FRANK/DOODY



000
FXUS61 KBOX 011206
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
706 AM EST SUN MAR 1 2015

.SYNOPSIS...
A FAST MOVING LOW PRESSURE SYSTEM WILL BRING ACCUMULATING SNOW
LATER TODAY AND ESPECIALLY TONIGHT WITH THE HIGHEST AMOUNTS
EXPECTED SOUTH OF THE MASSACHUSETTS TURNPIKE.HIGH PRESSURE BRINGS
DRY COLD AIR FOR THE EARLY WEEK. LOW PRESSURE FROM NORTHERN CANADA
AND ASSOCIATED LOW FORMING OVER THE PLAINS MONDAY WILL
MERGE...THEN PASS WEST AND NORTH OF NEW ENGLAND. THIS WILL SWING A
COLD FRONT ACROSS THE REGION ON WEDNESDAY. DRY AND COLD WEATHER
RETURNS FOR THE END OF THE WEEK.

&&

.NEAR TERM /UNTIL 3 PM THIS AFTERNOON/...
7 AM UPDATE...
FORECAST THIS MORNING IS MAINLY ON TRACK. ADDED A BIT MORE HIGH
CLOUDS AND SPED UP TIMING OF FLURRIES IN THE W AS RETURNS ARE
ALREADY VISIBLE ABOVE 10KFT ON KBOX. IT WILL TAKE SOME TIME FOR
THESE TO START REACHING THE GROUND THOUGH...BECAUSE DWPT
DEPRESSIONS ARE STILL 10F OR MORE ACROSS THE REGION WITH ACTUAL
DWPTS MAINLY IN THE NEGATIVE SINGLE DIGITS.

PREVIOUS DISCUSSION...

MID LEVEL CLOUDINESS WILL STREAM INTO SOUTHERN NEW ENGLAND AND
THICKEN DURING THE MORNING HOURS IN ADVANCE OF APPROACHING LOW
PRESSURE.  SOUTHWEST FLOW ALOFT OVERRUNING THE COLD DOME AT THE
SURFACE MAY ALLOW FOR SOME LIGHT SNOW/FLURRIES TO BREAK
OUT ACROSS THE INTERIOR LATE THIS MORNING/EARLY AFTERNOON AND THEN
FIND THEIR WAY TO THE COAST BY MID TO LATE AFTERNOON.  THE LIFT
THROUGH MID AFTERNOON IS FAIRLY WEAK...SO THE AREAS OF SNOW SHOULD
BE RATHER LIGHT. ANY ACCUMULATIONS THAT OCCUR WILL PROBABLY BE
A DUSTING TO LESS THAN 1 INCH THROUGH THAT THAT TIME.  HIGH TEMPS
WILL MAINLY BE IN THE UPPER 20S TO AROUND 30.

&&

.SHORT TERM /3 PM THIS AFTERNOON THROUGH 6 AM MONDAY/...
*** BULK OF THE ACCUMULATING SNOW OCCURS BETWEEN 3 PM AND 1 AM WITH
  THE HEAVIEST AMOUNTS SOUTH OF THE MA TURNPIKE ***

1) OVERVIEW AND TIMING:

THE BULK OF THE ACCUMULATING SNOW WILL OCCUR BETWEEN 3 PM AND
1 AM ACROSS THE REGION.  THE SNOW SHOULD TAPER OFF TO FLURRIES
TOWARD DAYBREAK MONDAY.  THE MODELS DO AGREE THAT THE BETTER FORCING
WILL OCCUR TO THE SOUTH OF THE MA TURNPIKE.  THIS A RESULT
OF SECONDARY LOW PRESSURE NEAR THE SOUTH COAST...ALLOWING FOR
SOME SURFACE CONVERGENCE AS WELL AS THE INTENSIFICATION OF THE LOW
LEVEL JET.

THE BIGGEST ISSUE IS THE MODELS ARE NOT IN AGREEMENT IN HOW
INTENSE THE FORCING WILL BE ACROSS THE REGION THIS EVENING.  THE
RGEM/NAM ARE THE MOST ROBUST WITH QPF SOUTH OF THE MA TURNPIKE.  THE
NAM SHOWS A PERIOD OF FAIRLY STRONG LIFT OF 15 TO 20 MICROBARS PER
SECOND WITHIN THE BEST SNOWGROWTH REGION THIS EVENING.  THIS WOULD
TRANSLATE TO A PERIOD OF 1+ INCH PER HOUR SNOWFALL RATES NEAR AND
SOUTH OF THE MA PIKE.  ON THE OTHER HAND...THE GFS ALSO HAS FAIRLY
STRONG LIFT...BUT KEEPS IT SOUTHEAST OF OUR REGION OUT OVER THE
OCEAN.  THE SECONDARY LOW PRESSURE SYSTEM ON THE GFS IS WEAKER AND
FURTHER SOUTHEAST...RESULTING IN THE LOW LEVEL JET BEING DISPLACED
FURTHER EAST.  THE ECMWF/UKMET SOLUTIONS SEEM TO BE THE MIDDLE
GROUND WHICH WE WILL LEAN TOWARDS.

2) WINTER WEATHER HEADLINES AND SNOW ACCUMS:

WITH THAT SAID...THE OTHER DILEMMA IS WHAT TO DO WITH THE CURRENT
HEADLINES.  THIS DOES NOT APPEAR TO BE THE TYPE OF SETUP WHERE WE
ARE GOING TO RECEIVE WIDESPREAD WARNING SNOWFALL AMOUNTS.  THE
WINDOW FOR THE VERY STRONG LIFT/FORCING IS SHORT-LIVED AND REALLY
WOULD LIKE TO SEE THE LOW LEVEL JET A BIT MORE BACKED TO TRANSPORT
DEEPER MOISTURE NORTHWARD.  THEREFORE...FEEL THAT FOR MOST OF THE
REGION WINTER WEATHER ADVISORY/S FOR 3 TO 6 INCHES OF SNOW WILL
COVER IT.  HOWEVER...GIVEN THERE IS NICE OMEGA IN THE SNOW GROWTH
REGION...WE MIGHT BE LOOKING AT SOME DECENT RATIOS.  SO WE STILL CAN
NOT RULE OUT THE LOW RISK OF REACHING WARNING AMOUNTS AND LATER
SHIFTS WILL HAVE TO MONITOR CLOSELY...ESPECIALLY ACROSS NORTHERN CT
AND NORTHWEST RI.

WE DID UPGRADE A SMALL AREA FROM CENTRAL AND SOUTHERN RHODE ISLAND
INTO SOUTHEAST MA INCLUDING THE SOUTH COAST TO A WINTER
STORM WARNING.  THE NOSE OF THE LOW LEVEL JET LOOKS TO TRANSPORT
SOME DEEPER MOISTURE INTO THIS REGION.  THERE ALSO COULD BE SOME
ENHANCEMENT ALONG THE LAND/SEA INTERFACE AND A WEAK SURFACE
BOUNDARY SO WENT WITH 4 TO 8 INCHES IN THIS REGION.

3) PTYPE AND IMPACTS:

THE MODELS HAVE TRENDED COLDER OVER THE PAST 24 HOURS.
THEREFORE...EXPECT THIS BE PRETTY MUCH A SNOW EVENT.  IT DOES BECOME
A VERY CLOSE CALL NEAR THE SOUTH COAST...BUT WERE LEANING TOWARDS IT
STAYING MAINLY WET SNOW.  IF PRECIPITATION LIGHTENS UP THAT MAY
INCREASE THIS RISK WE SEE A BRIEF CHANGE OVER TO RAIN.
MEANWHILE...WE WENT WITH A HIGH END WINTER WEATHER ADVISORY FOR THE
CAPE BECAUSE THEY MAY CHANGE TO RAIN FOR A TIME...ESPECIALLY EAST OF
HYANNIS.  IF THE CHANGE OVER DOES NOT OCCUR...WE MAY NEED TO UPGRADE
THEM TO A WINTER STORM WARNING ESPECIALLY NEAR THE CAPE COD CANAL
GIVEN EXPECTED QPF.

THE ONE THING WILL ALSO HAVE TO WATCH IS AREAS NEAR THE SOUTH COAST
AND CAPE COD.  LOOKS TO BE A WET SNOW DOWN THAT WAY AND ON GOING
ROOF ISSUES MAY BE EXACERBATED...ESPECIALLY IF ANY AREAS THAT ARE
ABLE TO EXCEED 6 INCHES OF WET SNOW.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
HIGHLIGHTS...

  * BLUSTERY CONDITIONS ON MON WITH DRY WEATHER CONTINUING INTO
    TUE.
  * A STORM SYSTEM BRINGS MIXED PRECIP TUE INTO WED.
  * CONDITIONS IMPROVE THU BUT BECOMING COLD AGAIN.

OVERVIEW AND MODEL PREFERENCES...
A SPLIT FLOW MERGER WILL BE THE DEFINING FACTOR THROUGH THE LONG
TERM FORECAST PERIOD. IN THE MID TERM...THE STREAMS MERGE THANKS
TO PHASING OF NRN AND SRN STREAM SHORTWAVES UPSTREAM AS MERGING
STRONG JET DEVELOPS ACROSS THE NE CONUS. THESE FEATURES WILL ALLOW
LOW PRES TO GRADUALLY DEEPEN AND SLIDE THROUGH SRN ONTARIO AND
QUEBEC...CREATING AN OVERRUNNING EVENT AS THE SYSTEM ATTEMPTS TO
OCCLUDE. THIS IS THE MIXED PRECIP EVENT WE HAVE BEEN DISCUSSING
FOR SOME TIME NOW. NOW THAT NAM HAS CAPTURED IT...IT APPEARS
COLDER THAN MOST OF THE DETERMINISTIC GUIDANCE...WHILE THE ECMWF
STARTS COLD AND SHIFTS TO THE WARMER SIDE OF THE ENVELOPE DUE TO
THE FACT THAT IT IS MORE AMPLIFIED THAN OTHER MODELS. THE
GFS...ECENS/GEFS MEANS ARE ACTUALLY A GOOD MIDDLE GROUND HERE.
THIS BLEND WILL BE USED THROUGH THE REMAINDER OF THE LONG TERM AS
WELL TO TAKE INTO ACCOUNT THE VARIOUS SOLUTIONS.

DETAILS...

MON INTO TUE...
REMNANT SNOWFALLS WILL BE GRADUALLY COMING TO AN END THROUGH MID
MORNING MON...ALTHOUGH FLURRIES MAY LINGER A BIT LONGER IN THE
BERKSHIRES. STRONG HIGH PRES WILL THEN SLIDE ACROSS THE REGION
THROUGH TUE...WITH MAINLY DRY WX. TEMPS LOOK TO REMAIN BELOW
NORMAL GIVEN LITTLE CHANGE IN THE AIRMASS FROM PREVIOUS DAYS.

TUE NIGHT INTO WED...
OVERRUNNING EVENT EXPECTED AS WARM FRONT WILL ATTEMPT TO PUSH N
ACROSS THE REGION BUT IS LIKELY TO STRUGGLE NEAR THE SFC DUE TO
ENTRENCHED COLD AIR AND A DEEP SNOWPACK. HOWEVER...50-60 KT LLJ
WITH STRONG SLY COMPONENT WILL ALLOW UPPER LVL WARMING TON
CONTINUE UNIMPEDED. IN SPITE OF THE STRONG JET AT ONLY 3-5KFT
ABOVE THE SFC...SNOWPACK WILL MAKE MIXING DIFFICULT SO NOT
EXPECTING SIGNIFICANT WIND ISSUES AT THIS TIME.

THE COLUMN STARTS COLD ENOUGH FOR SNOW AT ONSET TUE EVENING...AND
LOOKS LIKE AS MUCH AS 0.40-0.60 OF THE TOTAL EVENT QPF FALLS AS
SNOW INITIALLY EVERYWHERE...WITH GRADUAL CHANGEOVER DURING THE
EARLY MORNING HOURS WED MORNING FROM S-N. THEREFORE...COULD SEE AT
LEAST ADVISORY IF NOT LOW-END WARNING LVL SNOWFALLS THROUGH THE
OVERNIGHT HOURS BEFORE A TRANSITION TO SLEET...THEN FREEZING RAIN.
FREEZING RAIN COULD LOCK IN FOR SOME TIME AND GIVEN THAT H93 TEMPS
/EVEN ON THE COLDEST GUIDANCE/ AN AVERAGE OF +4C DURING THE 08Z-
16Z TIMEFRAME...BUT SFC TEMPS MAY HOLD NEAR FREEZING FOR SOME TIME
GIVEN THE DEEP SNOWPACK ACROSS THE AREA. HOWEVER...STRAIGHT RAIN
FOR A TIME FROM ABOUT MID MORNING INTO THE AFTERNOON IS LIKELY
UNTIL THE PRECIP COMES TO AN END. DEPENDING ON HOW QUICKLY 2M
TEMPS REBOUND...AS MUCH AS A QUARTER INCH OF ICE CAN/T BE RULED
OUT. AGREE WITH PREVIOUS FORECASTER THAT LEANING A BIT COLDER THAN
MOS 2M TEMPS IS PROBABLY THE WAY TO GO.

MODEST UPPER LVL INSTABILITY AS WARMING OCCURS IN THE MID LVLS
COULD ALSO MEAN A PERIOD OF HEAVY PRECIP...BOTH SNOW AND RAIN.
WITH THE RAIN...COMES A RISK FOR POOR DRAINAGE FLOODING ACROSS THE
REGION AS SNOW MELTS AND DRAINS BECOME CLOGGED. PRECIP COMES TO AN
END ACROSS MOST OF THE REGION BY AFTERNOON WED...BUT MAY LINGER A
BIT NEAR THE S COAST...MORE ON THAT BELOW.

WED NIGHT INTO THU...
CONFIDENCE IN THE FORECAST CONTINUES TO DIMINISH HERE PARTIALLY
DEPENDENT ON HOW FAST THE UPPER LVL JET EXITS TO THE EAST AND HOW
AMPLIFIED THE PATTERN REMAINS IN THE WAKE OF THE LOW PRES. THE
MORE AMPLIFIED GUIDANCE...LED BY THE ECMWF KEEPS THE COLD FRONT
JUST OFFSHORE AND WITHIN THE EQUATORWARD ENTRANCE REGION OF THE
UPPER LVL JET. THIS SUGGESTS S COASTAL AREAS COULD CONTINUE TO SEE
PRECIP...POSSIBLY EVEN CHANGING BACK TO SNOW FOR A TIME WELL INTO
THE DAY ON THU. THE MORE PROGRESSIVE GUIDANCE...LED BY THE GFS
WOULD MOVE BOTH OF THESE FEATURES OFFSHORE SUCH THAT THU IS
MAINLY DRY AND BECOMING QUITE COLD AS ANOTHER ARCTIC AIRMASS
SETTLES IN. FOR NOW...WILL CONTINUE TO LEAN ON THE MORE
PROGRESSIVE GFS BUT WITH THE ECENS/GEFS SLOWER MEMBERS BLENDED IN.
THE FINAL ANSWER WILL LIKELY BE SOMEWHERE IN BETWEEN THE TWO
SOLUTIONS. IN ANY CASE...MUCH COLDER AIRMASS EXPECTED TO MOVE IN.

THU NIGHT INTO FRI NIGHT...
COLD AIRMASS ACROSS THE REGION ASSOCIATED WITH YET ANOTHER 1035+
HPA HIGH PRES. WILL LIKELY SEE HIGHS ONLY MAKING THE TEENS AND 20S
WITH LOWS BACK IN THE SINGLE DIGITS ABOVE AND BELOW ZERO.

NEXT WEEKEND...
SOME UNCERTAINTY HERE AS TO WHETHER YET ANOTHER WAVE WILL BE
EFFECT THE REGION. WILL LEAN MAINLY DRY FOR NOW AS THE AIRMASS IN
PLACE IS QUITE DRY AND THE WAVE ITSELF IS QUITE WEAK AND SHEARING
OUT.

&&

.AVIATION /11Z SUNDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TODAY AND TONIGHT/...

12Z UPDATE...
NO MAJOR CHANGES TO THE TAFS...IT LOOKS LIKE FLURRIES MAY BEGIN
LATE THIS MORNING FROM W-E BUT WITH MAINLY VFR CONDITIONS. NOT
EXPECTING WIDESPREAD MVFR OR IFR UNTIL AFTER 18Z...SPREADING EAST
FROM THERE.

TODAY AND TONIGHT...MODERATE CONFIDENCE.
VFR CONDITIONS THROUGH AT LEAST MID MORNING. SOME MVFR TO IFR
CONDITIONS DEVELOP FROM WEST TO EAST LATE THIS MORNING AND THIS
AFTERNOON IN AREAS OF LIGHT SNOW. HOWEVER...THE BULK OF THE
MODERATE TO EVEN BRIEFLY HEAVY SNOW WILL OCCUR THIS EVENING WHEN
WIDESPREAD IFR TO LIFR CONDITIONS OCCUR. THE LOWER CONDITIONS MOST
LIKELY SOUTH OF THE MA TURNPIKE. PTYPE PRETTY MUCH ALL
SNOW...EXCEPT FOR THE VERY IMMEDIATE SOUTH COAST/CAPE WHERE SNOW
MAY MIX WITH OR CHANGE TO RAIN FOR A TIME. WHETHER OR NOT THAT
HAPPENS IS UNCERTAIN...BUT WE DO THINK THAT AT LEAST THE ISLANDS
WILL CHANGE TO RAIN.

BULK OF SNOW ENDS BY 8 OR 9Z TONIGHT AND MUCH OF THE THE REGION
SHOULD ALREADY HAVE VFR CONDITIONS BY 12Z MONDAY.

KBOS TAF...CONFIDENT IN OVERALL TRENDS BUT EXACT TIMING IS MORE
UNCERTAIN.  WHILE SOME LIGHT SNOW IS POSSIBLE THIS
AFTERNOON...BULK OF ACCUMULATING SNOW WITH WIDESPREAD IFR TO LIFR
CONDITIONS EXPECTED THIS EVENING.

KBDL TAF...CONFIDENT IN OVERALL TRENDS BUT EXACT TIMING IS MORE
UNCERTAIN.  WHILE SOME LIGHT SNOW IS POSSIBLE LATE THIS MORNING AND
AFTERNOON...BULK OF ACCUMULATING SNOW WITH WIDESPREAD IFR TO LIFR
CONDITIONS EXPECTED AFTER 3 OR 4 PM.

OUTLOOK...MONDAY THROUGH THURSDAY...

MONDAY...HIGH CONFIDENCE.
IFR/MVFR IN REMNANT SNOWS END EARLY...WITH TRANSITION TO VFR
EVERYWHERE BY AFTERNOON. W-NW WIND GUSTS UP TO AROUND 30 KT AT
TIMES DURING THE AFTERNOON AND EVENING.

MON NIGHT INTO TUE...HIGH CONFIDENCE.
MAINLY VFR. WINDS DIMINISH MON NIGHT.

TUE NIGHT INTO THU...MODERATE CONFIDENCE.
A MESSY PERIOD. SNOW BEGINS EVERYWHERE LATE TUE INTO WED NIGHT
WITH MODERATE ACCUMS POSSIBLE...THEN EXPECT GRADUALLY TRANSITION
TO SLEET AND FREEZING RAIN DURING THE EARLY MORNING HOURS
WED...THEN TO ALL RAIN DURING THE DAY ON WED. SOME ICE ACCUM
POSSIBLE AS WELL. THE RAIN DIMINISHES LATE WED BUT MAY LINGER
ALONG THE S COAST AND EVEN CHANGE TO SNOW INTO THE DAY ON THU.
EXPECT PERIODS OF IFR/LIFR CONDITIONS THROUGHOUT THE PERIOD WITH
SOME IMPROVEMENT FROM N-S ON THU. LLWS LIKELY ESPECIALLY TUE NIGHT
AND EARLY WED.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TODAY AND TONIGHT/...HIGH CONFIDENCE.

A WEAK WAVE OF LOW PRESSURE MOVES ACROSS THE WATERS LATER
TODAY AND TONIGHT.  WEAK PRESSURE GRADIENT SHOULD KEEP
WINDS/SEAS BELOW SMALL CRAFT THRESHOLDS TODAY AND TONIGHT.  THE
SYSTEM REALLY INTENSIFIES AS IT MOVES INTO THE CANADIAN MARITIMES
NEAR DAYBREAK MONDAY...SO WESTERLY WIND GUSTS MAY REACH 20 TO 25
KNOTS NEAR 12Z MONDAY.  OTHERWISE...RAIN AND SNOW LATE TODAY AND
ESPECIALLY TONIGHT WILL REDUCE VISIBILITIES AT TIMES FOR MARINERS.

OUTLOOK...MONDAY THROUGH THURSDAY..MODERATE CONFIDENCE.

MONDAY INTO MONDAY NIGHT...HIGH CONFIDENCE.
WINDS BEGIN OUT OF THE SW THEN SHIFT TO W-NW IN THE AFTERNOON.
WIND GUSTS REACH 35-40 KT DURING THE AFTERNOON AND OVERNIGHT SO
WILL BE ISSUING A GALE WATCH. SEAS BUILD 10-12 FT ON THE OCEAN
WATERS. SOME LIGHT FREEZING SPRAY POSSIBLE MON EVENING INTO TUE
MORNING.

TUE...HIGH CONFIDENCE.
WINDS AND SEAS START AT OR AROUND SMALL CRAFT ADVISORY THRESHOLDS
BUT THEN DROP DURING THE DAY SUCH THAT A PERIOD OF QUIET BOATING
WEATHER IS LIKELY TUE AFTERNOON AND EVENING.

TUE NIGHT INTO THU...MODERATE CONFIDENCE.
LOW PRES PASSES WELL INLAND...WITH WINDS OUT OF THE S GRADUALLY
SHIFTING TO THE W LATE WED INTO THU. PERIODS OF WIND GUSTS 25-30
KT EXPECTED ALTHOUGH GUSTS MAY APPROACH GALE FORCE WED EVENING.
SEAS BUILD THROUGH WED TO AROUND 7-10FT ON THE OCEAN WATERS THEN
DIMINISH THU. AT THE VERY LEAST SMALL CRAFT ADVISORIES ARE LIKELY
DURING THIS PERIOD. PERIODS OF SNOW CHANGING TO RAIN EARLY WED
WITH SOME LOW VSBYS IN RAIN AND FOG ON WED.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WINTER WEATHER ADVISORY FROM NOON TODAY TO 7 AM EST MONDAY FOR
     CTZ002>004.
MA...WINTER WEATHER ADVISORY FROM NOON TODAY TO 7 AM EST MONDAY FOR
     MAZ002>016-022>024-026.
     WINTER STORM WARNING FROM 3 PM THIS AFTERNOON TO 7 AM EST
     MONDAY FOR MAZ017>021.
RI...WINTER WEATHER ADVISORY FROM NOON TODAY TO 7 AM EST MONDAY FOR
     RIZ001-008.
     WINTER STORM WARNING FROM 3 PM THIS AFTERNOON TO 7 AM EST
     MONDAY FOR RIZ002>007.
MARINE...GALE WATCH FROM MONDAY MORNING THROUGH LATE MONDAY NIGHT FOR
     ANZ231>235-237-250-251-254>256.

&&

$$
SYNOPSIS...FRANK/DOODY
NEAR TERM...FRANK/DOODY
SHORT TERM...FRANK
LONG TERM...DOODY
AVIATION...FRANK/DOODY
MARINE...FRANK/DOODY




000
FXUS61 KBOX 010958
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
458 AM EST SUN MAR 1 2015

.SYNOPSIS...
A FAST MOVING LOW PRESSURE SYSTEM WILL BRING ACCUMULATING SNOW
LATER TODAY AND ESPECIALLY TONIGHT WITH THE HIGHEST AMOUNTS
EXPECTED SOUTH OF THE MASSACHUSETTS TURNPIKE.HIGH PRESSURE BRINGS
DRY COLD AIR FOR THE EARLY WEEK. LOW PRESSURE FROM NORTHERN CANADA
AND ASSOCIATED LOW FORMING OVER THE PLAINS MONDAY WILL
MERGE...THEN PASS WEST AND NORTH OF NEW ENGLAND. THIS WILL SWING A
COLD FRONT ACROSS THE REGION ON WEDNESDAY. DRY AND COLD WEATHER
RETURNS FOR THE END OF THE WEEK.

&&

.NEAR TERM /UNTIL 3 PM THIS AFTERNOON/...

MID LEVEL CLOUDINESS WILL STREAM INTO SOUTHERN NEW ENGLAND AND
THICKEN DURING THE MORNING HOURS IN ADVANCE OF APPROACHING LOW
PRESSURE.  SOUTHWEST FLOW ALOFT OVERRUNING THE COLD DOME AT THE
SURFACE MAY ALLOW FOR SOME LIGHT SNOW/FLURRIES TO BREAK
OUT ACROSS THE INTERIOR LATE THIS MORNING/EARLY AFTERNOON AND THEN
FIND THEIR WAY TO THE COAST BY MID TO LATE AFTERNOON.  THE LIFT
THROUGH MID AFTERNOON IS FAIRLY WEAK...SO THE AREAS OF SNOW SHOULD
BE RATHER LIGHT. ANY ACCUMULATIONS THAT OCCUR WILL PROBABLY BE
A DUSTING TO LESS THAN 1 INCH THROUGH THAT THAT TIME.  HIGH TEMPS
WILL MAINLY BE IN THE UPPER 20S TO AROUND 30.

&&

.SHORT TERM /3 PM THIS AFTERNOON THROUGH 6 AM MONDAY/...
*** BULK OF THE ACCUMULATING SNOW OCCURS BETWEEN 3 PM AND 1 AM WITH
  THE HEAVIEST AMOUNTS SOUTH OF THE MA TURNPIKE ***

1) OVERVIEW AND TIMING:

THE BULK OF THE ACCUMULATING SNOW WILL OCCUR BETWEEN 3 PM AND
1 AM ACROSS THE REGION.  THE SNOW SHOULD TAPER OFF TO FLURRIES
TOWARD DAYBREAK MONDAY.  THE MODELS DO AGREE THAT THE BETTER FORCING
WILL OCCUR TO THE SOUTH OF THE MA TURNPIKE.  THIS A RESULT
OF SECONDARY LOW PRESSURE NEAR THE SOUTH COAST...ALLOWING FOR
SOME SURFACE CONVERGENCE AS WELL AS THE INTENSIFICATION OF THE LOW
LEVEL JET.

THE BIGGEST ISSUE IS THE MODELS ARE NOT IN AGREEMENT IN HOW
INTENSE THE FORCING WILL BE ACROSS THE REGION THIS EVENING.  THE
RGEM/NAM ARE THE MOST ROBUST WITH QPF SOUTH OF THE MA TURNPIKE.  THE
NAM SHOWS A PERIOD OF FAIRLY STRONG LIFT OF 15 TO 20 MICROBARS PER
SECOND WITHIN THE BEST SNOWGROWTH REGION THIS EVENING.  THIS WOULD
TRANSLATE TO A PERIOD OF 1+ INCH PER HOUR SNOWFALL RATES NEAR AND
SOUTH OF THE MA PIKE.  ON THE OTHER HAND...THE GFS ALSO HAS FAIRLY
STRONG LIFT...BUT KEEPS IT SOUTHEAST OF OUR REGION OUT OVER THE
OCEAN.  THE SECONDARY LOW PRESSURE SYSTEM ON THE GFS IS WEAKER AND
FURTHER SOUTHEAST...RESULTING IN THE LOW LEVEL JET BEING DISPLACED
FURTHER EAST.  THE ECMWF/UKMET SOLUTIONS SEEM TO BE THE MIDDLE
GROUND WHICH WE WILL LEAN TOWARDS.

2) WINTER WEATHER HEADLINES AND SNOW ACCUMS:

WITH THAT SAID...THE OTHER DILEMMA IS WHAT TO DO WITH THE CURRENT
HEADLINES.  THIS DOES NOT APPEAR TO BE THE TYPE OF SETUP WHERE WE
ARE GOING TO RECEIVE WIDESPREAD WARNING SNOWFALL AMOUNTS.  THE
WINDOW FOR THE VERY STRONG LIFT/FORCING IS SHORT-LIVED AND REALLY
WOULD LIKE TO SEE THE LOW LEVEL JET A BIT MORE BACKED TO TRANSPORT
DEEPER MOISTURE NORTHWARD.  THEREFORE...FEEL THAT FOR MOST OF THE
REGION WINTER WEATHER ADVISORY/S FOR 3 TO 6 INCHES OF SNOW WILL
COVER IT.  HOWEVER...GIVEN THERE IS NICE OMEGA IN THE SNOW GROWTH
REGION...WE MIGHT BE LOOKING AT SOME DECENT RATIOS.  SO WE STILL CAN
NOT RULE OUT THE LOW RISK OF REACHING WARNING AMOUNTS AND LATER
SHIFTS WILL HAVE TO MONITOR CLOSELY...ESPECIALLY ACROSS NORTHERN CT
AND NORTHWEST RI.

WE DID UPGRADE A SMALL AREA FROM CENTRAL AND SOUTHERN RHODE ISLAND
INTO SOUTHEAST MA INCLUDING THE SOUTH COAST TO A WINTER
STORM WARNING.  THE NOSE OF THE LOW LEVEL JET LOOKS TO TRANSPORT
SOME DEEPER MOISTURE INTO THIS REGION.  THERE ALSO COULD BE SOME
ENHANCEMENT ALONG THE LAND/SEA INTERFACE AND A WEAK SURFACE
BOUNDARY SO WENT WITH 4 TO 8 INCHES IN THIS REGION.

3) PTYPE AND IMPACTS:

THE MODELS HAVE TRENDED COLDER OVER THE PAST 24 HOURS.
THEREFORE...EXPECT THIS BE PRETTY MUCH A SNOW EVENT.  IT DOES BECOME
A VERY CLOSE CALL NEAR THE SOUTH COAST...BUT WERE LEANING TOWARDS IT
STAYING MAINLY WET SNOW.  IF PRECIPITATION LIGHTENS UP THAT MAY
INCREASE THIS RISK WE SEE A BRIEF CHANGE OVER TO RAIN.
MEANWHILE...WE WENT WITH A HIGH END WINTER WEATHER ADVISORY FOR THE
CAPE BECAUSE THEY MAY CHANGE TO RAIN FOR A TIME...ESPECIALLY EAST OF
HYANNIS.  IF THE CHANGE OVER DOES NOT OCCUR...WE MAY NEED TO UPGRADE
THEM TO A WINTER STORM WARNING ESPECIALLY NEAR THE CAPE COD CANAL
GIVEN EXPECTED QPF.

THE ONE THING WILL ALSO HAVE TO WATCH IS AREAS NEAR THE SOUTH COAST
AND CAPE COD.  LOOKS TO BE A WET SNOW DOWN THAT WAY AND ON GOING
ROOF ISSUES MAY BE EXACERBATED...ESPECIALLY IF ANY AREAS THAT ARE
ABLE TO EXCEED 6 INCHES OF WET SNOW.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
HIGHLIGHTS...

  * BLUSTERY CONDITIONS ON MON WITH DRY WEATHER CONTINUING INTO
    TUE.
  * A STORM SYSTEM BRINGS MIXED PRECIP TUE INTO WED.
  * CONDITIONS IMPROVE THU BUT BECOMING COLD AGAIN.

OVERVIEW AND MODEL PREFERENCES...
A SPLIT FLOW MERGER WILL BE THE DEFINING FACTOR THROUGH THE LONG
TERM FORECAST PERIOD. IN THE MID TERM...THE STREAMS MERGE THANKS
TO PHASING OF NRN AND SRN STREAM SHORTWAVES UPSTREAM AS MERGING
STRONG JET DEVELOPS ACROSS THE NE CONUS. THESE FEATURES WILL ALLOW
LOW PRES TO GRADUALLY DEEPEN AND SLIDE THROUGH SRN ONTARIO AND
QUEBEC...CREATING AN OVERRUNNING EVENT AS THE SYSTEM ATTEMPTS TO
OCCLUDE. THIS IS THE MIXED PRECIP EVENT WE HAVE BEEN DISCUSSING
FOR SOME TIME NOW. NOW THAT NAM HAS CAPTURED IT...IT APPEARS
COLDER THAN MOST OF THE DETERMINISTIC GUIDANCE...WHILE THE ECMWF
STARTS COLD AND SHIFTS TO THE WARMER SIDE OF THE ENVELOPE DUE TO
THE FACT THAT IT IS MORE AMPLIFIED THAN OTHER MODELS. THE
GFS...ECENS/GEFS MEANS ARE ACTUALLY A GOOD MIDDLE GROUND HERE.
THIS BLEND WILL BE USED THROUGH THE REMAINDER OF THE LONG TERM AS
WELL TO TAKE INTO ACCOUNT THE VARIOUS SOLUTIONS.

DETAILS...

MON INTO TUE...
REMNANT SNOWFALLS WILL BE GRADUALLY COMING TO AN END THROUGH MID
MORNING MON...ALTHOUGH FLURRIES MAY LINGER A BIT LONGER IN THE
BERKSHIRES. STRONG HIGH PRES WILL THEN SLIDE ACROSS THE REGION
THROUGH TUE...WITH MAINLY DRY WX. TEMPS LOOK TO REMAIN BELOW
NORMAL GIVEN LITTLE CHANGE IN THE AIRMASS FROM PREVIOUS DAYS.

TUE NIGHT INTO WED...
OVERRUNNING EVENT EXPECTED AS WARM FRONT WILL ATTEMPT TO PUSH N
ACROSS THE REGION BUT IS LIKELY TO STRUGGLE NEAR THE SFC DUE TO
ENTRENCHED COLD AIR AND A DEEP SNOWPACK. HOWEVER...50-60 KT LLJ
WITH STRONG SLY COMPONENT WILL ALLOW UPPER LVL WARMING TON
CONTINUE UNIMPEDED. IN SPITE OF THE STRONG JET AT ONLY 3-5KFT
ABOVE THE SFC...SNOWPACK WILL MAKE MIXING DIFFICULT SO NOT
EXPECTING SIGNIFICANT WIND ISSUES AT THIS TIME.

THE COLUMN STARTS COLD ENOUGH FOR SNOW AT ONSET TUE EVENING...AND
LOOKS LIKE AS MUCH AS 0.40-0.60 OF THE TOTAL EVENT QPF FALLS AS
SNOW INITIALLY EVERYWHERE...WITH GRADUAL CHANGEOVER DURING THE
EARLY MORNING HOURS WED MORNING FROM S-N. THEREFORE...COULD SEE AT
LEAST ADVISORY IF NOT LOW-END WARNING LVL SNOWFALLS THROUGH THE
OVERNIGHT HOURS BEFORE A TRANSITION TO SLEET...THEN FREEZING RAIN.
FREEZING RAIN COULD LOCK IN FOR SOME TIME AND GIVEN THAT H93 TEMPS
/EVEN ON THE COLDEST GUIDANCE/ AN AVERAGE OF +4C DURING THE 08Z-
16Z TIMEFRAME...BUT SFC TEMPS MAY HOLD NEAR FREEZING FOR SOME TIME
GIVEN THE DEEP SNOWPACK ACROSS THE AREA. HOWEVER...STRAIGHT RAIN
FOR A TIME FROM ABOUT MID MORNING INTO THE AFTERNOON IS LIKELY
UNTIL THE PRECIP COMES TO AN END. DEPENDING ON HOW QUICKLY 2M
TEMPS REBOUND...AS MUCH AS A QUARTER INCH OF ICE CAN/T BE RULED
OUT. AGREE WITH PREVIOUS FORECASTER THAT LEANING A BIT COLDER THAN
MOS 2M TEMPS IS PROBABLY THE WAY TO GO.

MODEST UPPER LVL INSTABILITY AS WARMING OCCURS IN THE MID LVLS
COULD ALSO MEAN A PERIOD OF HEAVY PRECIP...BOTH SNOW AND RAIN.
WITH THE RAIN...COMES A RISK FOR POOR DRAINAGE FLOODING ACROSS THE
REGION AS SNOW MELTS AND DRAINS BECOME CLOGGED. PRECIP COMES TO AN
END ACROSS MOST OF THE REGION BY AFTERNOON WED...BUT MAY LINGER A
BIT NEAR THE S COAST...MORE ON THAT BELOW.

WED NIGHT INTO THU...
CONFIDENCE IN THE FORECAST CONTINUES TO DIMINISH HERE PARTIALLY
DEPENDENT ON HOW FAST THE UPPER LVL JET EXITS TO THE EAST AND HOW
AMPLIFIED THE PATTERN REMAINS IN THE WAKE OF THE LOW PRES. THE
MORE AMPLIFIED GUIDANCE...LED BY THE ECMWF KEEPS THE COLD FRONT
JUST OFFSHORE AND WITHIN THE EQUATORWARD ENTRANCE REGION OF THE
UPPER LVL JET. THIS SUGGESTS S COASTAL AREAS COULD CONTINUE TO SEE
PRECIP...POSSIBLY EVEN CHANGING BACK TO SNOW FOR A TIME WELL INTO
THE DAY ON THU. THE MORE PROGRESSIVE GUIDANCE...LED BY THE GFS
WOULD MOVE BOTH OF THESE FEATURES OFFSHORE SUCH THAT THU IS
MAINLY DRY AND BECOMING QUITE COLD AS ANOTHER ARCTIC AIRMASS
SETTLES IN. FOR NOW...WILL CONTINUE TO LEAN ON THE MORE
PROGRESSIVE GFS BUT WITH THE ECENS/GEFS SLOWER MEMBERS BLENDED IN.
THE FINAL ANSWER WILL LIKELY BE SOMEWHERE IN BETWEEN THE TWO
SOLUTIONS. IN ANY CASE...MUCH COLDER AIRMASS EXPECTED TO MOVE IN.

THU NIGHT INTO FRI NIGHT...
COLD AIRMASS ACROSS THE REGION ASSOCIATED WITH YET ANOTHER 1035+
HPA HIGH PRES. WILL LIKELY SEE HIGHS ONLY MAKING THE TEENS AND 20S
WITH LOWS BACK IN THE SINGLE DIGITS ABOVE AND BELOW ZERO.

NEXT WEEKEND...
SOME UNCERTAINTY HERE AS TO WHETHER YET ANOTHER WAVE WILL BE
EFFECT THE REGION. WILL LEAN MAINLY DRY FOR NOW AS THE AIRMASS IN
PLACE IS QUITE DRY AND THE WAVE ITSELF IS QUITE WEAK AND SHEARING
OUT.

&&

.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TODAY AND TONIGHT/...

TODAY AND TONIGHT...MODERATE CONFIDENCE.  VFR CONDITIONS THROUGH AT
LEAST MID MORNING.  SOME MVFR TO IFR CONDITIONS DEVELOP FROM WEST TO
EAST LATE THIS MORNING AND THIS AFTERNOON IN AREAS OF LIGHT SNOW.
HOWEVER...THE BULK OF THE MODERATE TO EVEN BRIEFLY HEAVY SNOW WILL
OCCUR THIS EVENING WHEN WIDESPREAD IFR TO LIFR CONDITIONS OCCUR.
THE LOWER CONDITIONS MOST LIKELY SOUTH OF THE MA TURNPIKE.  PTYPE
PRETTY MUCH ALL SNOW...EXCEPT FOR THE VERY IMMEDIATE SOUTH
COAST/CAPE WHERE SNOW MAY MIX WITH OR CHANGE TO RAIN FOR A TIME.
WHETHER OR NOT THAT HAPPENS IS UNCERTAIN...BUT WE DO THINK THAT AT
LEAST THE ISLANDS WILL CHANGE TO RAIN.

BULK OF SNOW ENDS BY 8 OR 9Z TONIGHT AND MUCH OF THE THE REGION
SHOULD ALREADY HAVE VFR CONDITIONS BY 12Z MONDAY.

KBOS TAF...CONFIDENT IN OVERALL TRENDS BUT EXACT TIMING IS MORE
UNCERTAIN.  WHILE SOME LIGHT SNOW IS POSSIBLE THIS
AFTERNOON...BULK OF ACCUMULATING SNOW WITH WIDESPREAD IFR TO LIFR
CONDITIONS EXPECTED THIS EVENING.

KBDL TAF...CONFIDENT IN OVERALL TRENDS BUT EXACT TIMING IS MORE
UNCERTAIN.  WHILE SOME LIGHT SNOW IS POSSIBLE LATE THIS MORNING AND
AFTERNOON...BULK OF ACCUMULATING SNOW WITH WIDESPREAD IFR TO LIFR
CONDITIONS EXPECTED AFTER 3 OR 4 PM.

OUTLOOK...MONDAY THROUGH THURSDAY...

MONDAY...HIGH CONFIDENCE.
IFR/MVFR IN REMNANT SNOWS END EARLY...WITH TRANSITION TO VFR
EVERYWHERE BY AFTERNOON. W-NW WIND GUSTS UP TO AROUND 30 KT AT
TIMES DURING THE AFTERNOON AND EVENING.

MON NIGHT INTO TUE...HIGH CONFIDENCE.
MAINLY VFR. WINDS DIMINISH MON NIGHT.

TUE NIGHT INTO THU...MODERATE CONFIDENCE.
A MESSY PERIOD. SNOW BEGINS EVERYWHERE LATE TUE INTO WED NIGHT
WITH MODERATE ACCUMS POSSIBLE...THEN EXPECT GRADUALLY TRANSITION
TO SLEET AND FREEZING RAIN DURING THE EARLY MORNING HOURS
WED...THEN TO ALL RAIN DURING THE DAY ON WED. SOME ICE ACCUM
POSSIBLE AS WELL. THE RAIN DIMINISHES LATE WED BUT MAY LINGER
ALONG THE S COAST AND EVEN CHANGE TO SNOW INTO THE DAY ON THU.
EXPECT PERIODS OF IFR/LIFR CONDITIONS THROUGHOUT THE PERIOD WITH
SOME IMPROVEMENT FROM N-S ON THU. LLWS LIKELY ESPECIALLY TUE NIGHT
AND EARLY WED.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TODAY AND TONIGHT/...HIGH CONFIDENCE.

A WEAK WAVE OF LOW PRESSURE MOVES ACROSS THE WATERS LATER
TODAY AND TONIGHT.  WEAK PRESSURE GRADIENT SHOULD KEEP
WINDS/SEAS BELOW SMALL CRAFT THRESHOLDS TODAY AND TONIGHT.  THE
SYSTEM REALLY INTENSIFIES AS IT MOVES INTO THE CANADIAN MARITIMES
NEAR DAYBREAK MONDAY...SO WESTERLY WIND GUSTS MAY REACH 20 TO 25
KNOTS NEAR 12Z MONDAY.  OTHERWISE...RAIN AND SNOW LATE TODAY AND
ESPECIALLY TONIGHT WILL REDUCE VISIBILITIES AT TIMES FOR MARINERS.

OUTLOOK...MONDAY THROUGH THURSDAY..MODERATE CONFIDENCE.

MONDAY INTO MONDAY NIGHT...HIGH CONFIDENCE.
WINDS BEGIN OUT OF THE SW THEN SHIFT TO W-NW IN THE AFTERNOON.
WIND GUSTS REACH 35-40 KT DURING THE AFTERNOON AND OVERNIGHT SO
WILL BE ISSUING A GALE WATCH. SEAS BUILD 10-12 FT ON THE OCEAN
WATERS. SOME LIGHT FREEZING SPRAY POSSIBLE MON EVENING INTO TUE
MORNING.

TUE...HIGH CONFIDENCE.
WINDS AND SEAS START AT OR AROUND SMALL CRAFT ADVISORY THRESHOLDS
BUT THEN DROP DURING THE DAY SUCH THAT A PERIOD OF QUIET BOATING
WEATHER IS LIKELY TUE AFTERNOON AND EVENING.

TUE NIGHT INTO THU...MODERATE CONFIDENCE.
LOW PRES PASSES WELL INLAND...WITH WINDS OUT OF THE S GRADUALLY
SHIFTING TO THE W LATE WED INTO THU. PERIODS OF WIND GUSTS 25-30
KT EXPECTED ALTHOUGH GUSTS MAY APPROACH GALE FORCE WED EVENING.
SEAS BUILD THROUGH WED TO AROUND 7-10FT ON THE OCEAN WATERS THEN
DIMINISH THU. AT THE VERY LEAST SMALL CRAFT ADVISORIES ARE LIKELY
DURING THIS PERIOD. PERIODS OF SNOW CHANGING TO RAIN EARLY WED
WITH SOME LOW VSBYS IN RAIN AND FOG ON WED.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WINTER WEATHER ADVISORY FROM NOON TODAY TO 7 AM EST MONDAY FOR
     CTZ002>004.
MA...WINTER WEATHER ADVISORY FROM NOON TODAY TO 7 AM EST MONDAY FOR
     MAZ002>016-022>024-026.
     WINTER STORM WARNING FROM 3 PM THIS AFTERNOON TO 7 AM EST
     MONDAY FOR MAZ017>021.
RI...WINTER WEATHER ADVISORY FROM NOON TODAY TO 7 AM EST MONDAY FOR
     RIZ001-008.
     WINTER STORM WARNING FROM 3 PM THIS AFTERNOON TO 7 AM EST
     MONDAY FOR RIZ002>007.
MARINE...GALE WATCH FROM MONDAY MORNING THROUGH LATE MONDAY NIGHT FOR
     ANZ231>235-237-250-251-254>256.

&&

$$
SYNOPSIS...FRANK/DOODY
NEAR TERM...FRANK
SHORT TERM...FRANK
LONG TERM...DOODY
AVIATION...FRANK/DOODY
MARINE...FRANK/DOODY



000
FXUS61 KBOX 010958
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
458 AM EST SUN MAR 1 2015

.SYNOPSIS...
A FAST MOVING LOW PRESSURE SYSTEM WILL BRING ACCUMULATING SNOW
LATER TODAY AND ESPECIALLY TONIGHT WITH THE HIGHEST AMOUNTS
EXPECTED SOUTH OF THE MASSACHUSETTS TURNPIKE.HIGH PRESSURE BRINGS
DRY COLD AIR FOR THE EARLY WEEK. LOW PRESSURE FROM NORTHERN CANADA
AND ASSOCIATED LOW FORMING OVER THE PLAINS MONDAY WILL
MERGE...THEN PASS WEST AND NORTH OF NEW ENGLAND. THIS WILL SWING A
COLD FRONT ACROSS THE REGION ON WEDNESDAY. DRY AND COLD WEATHER
RETURNS FOR THE END OF THE WEEK.

&&

.NEAR TERM /UNTIL 3 PM THIS AFTERNOON/...

MID LEVEL CLOUDINESS WILL STREAM INTO SOUTHERN NEW ENGLAND AND
THICKEN DURING THE MORNING HOURS IN ADVANCE OF APPROACHING LOW
PRESSURE.  SOUTHWEST FLOW ALOFT OVERRUNING THE COLD DOME AT THE
SURFACE MAY ALLOW FOR SOME LIGHT SNOW/FLURRIES TO BREAK
OUT ACROSS THE INTERIOR LATE THIS MORNING/EARLY AFTERNOON AND THEN
FIND THEIR WAY TO THE COAST BY MID TO LATE AFTERNOON.  THE LIFT
THROUGH MID AFTERNOON IS FAIRLY WEAK...SO THE AREAS OF SNOW SHOULD
BE RATHER LIGHT. ANY ACCUMULATIONS THAT OCCUR WILL PROBABLY BE
A DUSTING TO LESS THAN 1 INCH THROUGH THAT THAT TIME.  HIGH TEMPS
WILL MAINLY BE IN THE UPPER 20S TO AROUND 30.

&&

.SHORT TERM /3 PM THIS AFTERNOON THROUGH 6 AM MONDAY/...
*** BULK OF THE ACCUMULATING SNOW OCCURS BETWEEN 3 PM AND 1 AM WITH
  THE HEAVIEST AMOUNTS SOUTH OF THE MA TURNPIKE ***

1) OVERVIEW AND TIMING:

THE BULK OF THE ACCUMULATING SNOW WILL OCCUR BETWEEN 3 PM AND
1 AM ACROSS THE REGION.  THE SNOW SHOULD TAPER OFF TO FLURRIES
TOWARD DAYBREAK MONDAY.  THE MODELS DO AGREE THAT THE BETTER FORCING
WILL OCCUR TO THE SOUTH OF THE MA TURNPIKE.  THIS A RESULT
OF SECONDARY LOW PRESSURE NEAR THE SOUTH COAST...ALLOWING FOR
SOME SURFACE CONVERGENCE AS WELL AS THE INTENSIFICATION OF THE LOW
LEVEL JET.

THE BIGGEST ISSUE IS THE MODELS ARE NOT IN AGREEMENT IN HOW
INTENSE THE FORCING WILL BE ACROSS THE REGION THIS EVENING.  THE
RGEM/NAM ARE THE MOST ROBUST WITH QPF SOUTH OF THE MA TURNPIKE.  THE
NAM SHOWS A PERIOD OF FAIRLY STRONG LIFT OF 15 TO 20 MICROBARS PER
SECOND WITHIN THE BEST SNOWGROWTH REGION THIS EVENING.  THIS WOULD
TRANSLATE TO A PERIOD OF 1+ INCH PER HOUR SNOWFALL RATES NEAR AND
SOUTH OF THE MA PIKE.  ON THE OTHER HAND...THE GFS ALSO HAS FAIRLY
STRONG LIFT...BUT KEEPS IT SOUTHEAST OF OUR REGION OUT OVER THE
OCEAN.  THE SECONDARY LOW PRESSURE SYSTEM ON THE GFS IS WEAKER AND
FURTHER SOUTHEAST...RESULTING IN THE LOW LEVEL JET BEING DISPLACED
FURTHER EAST.  THE ECMWF/UKMET SOLUTIONS SEEM TO BE THE MIDDLE
GROUND WHICH WE WILL LEAN TOWARDS.

2) WINTER WEATHER HEADLINES AND SNOW ACCUMS:

WITH THAT SAID...THE OTHER DILEMMA IS WHAT TO DO WITH THE CURRENT
HEADLINES.  THIS DOES NOT APPEAR TO BE THE TYPE OF SETUP WHERE WE
ARE GOING TO RECEIVE WIDESPREAD WARNING SNOWFALL AMOUNTS.  THE
WINDOW FOR THE VERY STRONG LIFT/FORCING IS SHORT-LIVED AND REALLY
WOULD LIKE TO SEE THE LOW LEVEL JET A BIT MORE BACKED TO TRANSPORT
DEEPER MOISTURE NORTHWARD.  THEREFORE...FEEL THAT FOR MOST OF THE
REGION WINTER WEATHER ADVISORY/S FOR 3 TO 6 INCHES OF SNOW WILL
COVER IT.  HOWEVER...GIVEN THERE IS NICE OMEGA IN THE SNOW GROWTH
REGION...WE MIGHT BE LOOKING AT SOME DECENT RATIOS.  SO WE STILL CAN
NOT RULE OUT THE LOW RISK OF REACHING WARNING AMOUNTS AND LATER
SHIFTS WILL HAVE TO MONITOR CLOSELY...ESPECIALLY ACROSS NORTHERN CT
AND NORTHWEST RI.

WE DID UPGRADE A SMALL AREA FROM CENTRAL AND SOUTHERN RHODE ISLAND
INTO SOUTHEAST MA INCLUDING THE SOUTH COAST TO A WINTER
STORM WARNING.  THE NOSE OF THE LOW LEVEL JET LOOKS TO TRANSPORT
SOME DEEPER MOISTURE INTO THIS REGION.  THERE ALSO COULD BE SOME
ENHANCEMENT ALONG THE LAND/SEA INTERFACE AND A WEAK SURFACE
BOUNDARY SO WENT WITH 4 TO 8 INCHES IN THIS REGION.

3) PTYPE AND IMPACTS:

THE MODELS HAVE TRENDED COLDER OVER THE PAST 24 HOURS.
THEREFORE...EXPECT THIS BE PRETTY MUCH A SNOW EVENT.  IT DOES BECOME
A VERY CLOSE CALL NEAR THE SOUTH COAST...BUT WERE LEANING TOWARDS IT
STAYING MAINLY WET SNOW.  IF PRECIPITATION LIGHTENS UP THAT MAY
INCREASE THIS RISK WE SEE A BRIEF CHANGE OVER TO RAIN.
MEANWHILE...WE WENT WITH A HIGH END WINTER WEATHER ADVISORY FOR THE
CAPE BECAUSE THEY MAY CHANGE TO RAIN FOR A TIME...ESPECIALLY EAST OF
HYANNIS.  IF THE CHANGE OVER DOES NOT OCCUR...WE MAY NEED TO UPGRADE
THEM TO A WINTER STORM WARNING ESPECIALLY NEAR THE CAPE COD CANAL
GIVEN EXPECTED QPF.

THE ONE THING WILL ALSO HAVE TO WATCH IS AREAS NEAR THE SOUTH COAST
AND CAPE COD.  LOOKS TO BE A WET SNOW DOWN THAT WAY AND ON GOING
ROOF ISSUES MAY BE EXACERBATED...ESPECIALLY IF ANY AREAS THAT ARE
ABLE TO EXCEED 6 INCHES OF WET SNOW.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
HIGHLIGHTS...

  * BLUSTERY CONDITIONS ON MON WITH DRY WEATHER CONTINUING INTO
    TUE.
  * A STORM SYSTEM BRINGS MIXED PRECIP TUE INTO WED.
  * CONDITIONS IMPROVE THU BUT BECOMING COLD AGAIN.

OVERVIEW AND MODEL PREFERENCES...
A SPLIT FLOW MERGER WILL BE THE DEFINING FACTOR THROUGH THE LONG
TERM FORECAST PERIOD. IN THE MID TERM...THE STREAMS MERGE THANKS
TO PHASING OF NRN AND SRN STREAM SHORTWAVES UPSTREAM AS MERGING
STRONG JET DEVELOPS ACROSS THE NE CONUS. THESE FEATURES WILL ALLOW
LOW PRES TO GRADUALLY DEEPEN AND SLIDE THROUGH SRN ONTARIO AND
QUEBEC...CREATING AN OVERRUNNING EVENT AS THE SYSTEM ATTEMPTS TO
OCCLUDE. THIS IS THE MIXED PRECIP EVENT WE HAVE BEEN DISCUSSING
FOR SOME TIME NOW. NOW THAT NAM HAS CAPTURED IT...IT APPEARS
COLDER THAN MOST OF THE DETERMINISTIC GUIDANCE...WHILE THE ECMWF
STARTS COLD AND SHIFTS TO THE WARMER SIDE OF THE ENVELOPE DUE TO
THE FACT THAT IT IS MORE AMPLIFIED THAN OTHER MODELS. THE
GFS...ECENS/GEFS MEANS ARE ACTUALLY A GOOD MIDDLE GROUND HERE.
THIS BLEND WILL BE USED THROUGH THE REMAINDER OF THE LONG TERM AS
WELL TO TAKE INTO ACCOUNT THE VARIOUS SOLUTIONS.

DETAILS...

MON INTO TUE...
REMNANT SNOWFALLS WILL BE GRADUALLY COMING TO AN END THROUGH MID
MORNING MON...ALTHOUGH FLURRIES MAY LINGER A BIT LONGER IN THE
BERKSHIRES. STRONG HIGH PRES WILL THEN SLIDE ACROSS THE REGION
THROUGH TUE...WITH MAINLY DRY WX. TEMPS LOOK TO REMAIN BELOW
NORMAL GIVEN LITTLE CHANGE IN THE AIRMASS FROM PREVIOUS DAYS.

TUE NIGHT INTO WED...
OVERRUNNING EVENT EXPECTED AS WARM FRONT WILL ATTEMPT TO PUSH N
ACROSS THE REGION BUT IS LIKELY TO STRUGGLE NEAR THE SFC DUE TO
ENTRENCHED COLD AIR AND A DEEP SNOWPACK. HOWEVER...50-60 KT LLJ
WITH STRONG SLY COMPONENT WILL ALLOW UPPER LVL WARMING TON
CONTINUE UNIMPEDED. IN SPITE OF THE STRONG JET AT ONLY 3-5KFT
ABOVE THE SFC...SNOWPACK WILL MAKE MIXING DIFFICULT SO NOT
EXPECTING SIGNIFICANT WIND ISSUES AT THIS TIME.

THE COLUMN STARTS COLD ENOUGH FOR SNOW AT ONSET TUE EVENING...AND
LOOKS LIKE AS MUCH AS 0.40-0.60 OF THE TOTAL EVENT QPF FALLS AS
SNOW INITIALLY EVERYWHERE...WITH GRADUAL CHANGEOVER DURING THE
EARLY MORNING HOURS WED MORNING FROM S-N. THEREFORE...COULD SEE AT
LEAST ADVISORY IF NOT LOW-END WARNING LVL SNOWFALLS THROUGH THE
OVERNIGHT HOURS BEFORE A TRANSITION TO SLEET...THEN FREEZING RAIN.
FREEZING RAIN COULD LOCK IN FOR SOME TIME AND GIVEN THAT H93 TEMPS
/EVEN ON THE COLDEST GUIDANCE/ AN AVERAGE OF +4C DURING THE 08Z-
16Z TIMEFRAME...BUT SFC TEMPS MAY HOLD NEAR FREEZING FOR SOME TIME
GIVEN THE DEEP SNOWPACK ACROSS THE AREA. HOWEVER...STRAIGHT RAIN
FOR A TIME FROM ABOUT MID MORNING INTO THE AFTERNOON IS LIKELY
UNTIL THE PRECIP COMES TO AN END. DEPENDING ON HOW QUICKLY 2M
TEMPS REBOUND...AS MUCH AS A QUARTER INCH OF ICE CAN/T BE RULED
OUT. AGREE WITH PREVIOUS FORECASTER THAT LEANING A BIT COLDER THAN
MOS 2M TEMPS IS PROBABLY THE WAY TO GO.

MODEST UPPER LVL INSTABILITY AS WARMING OCCURS IN THE MID LVLS
COULD ALSO MEAN A PERIOD OF HEAVY PRECIP...BOTH SNOW AND RAIN.
WITH THE RAIN...COMES A RISK FOR POOR DRAINAGE FLOODING ACROSS THE
REGION AS SNOW MELTS AND DRAINS BECOME CLOGGED. PRECIP COMES TO AN
END ACROSS MOST OF THE REGION BY AFTERNOON WED...BUT MAY LINGER A
BIT NEAR THE S COAST...MORE ON THAT BELOW.

WED NIGHT INTO THU...
CONFIDENCE IN THE FORECAST CONTINUES TO DIMINISH HERE PARTIALLY
DEPENDENT ON HOW FAST THE UPPER LVL JET EXITS TO THE EAST AND HOW
AMPLIFIED THE PATTERN REMAINS IN THE WAKE OF THE LOW PRES. THE
MORE AMPLIFIED GUIDANCE...LED BY THE ECMWF KEEPS THE COLD FRONT
JUST OFFSHORE AND WITHIN THE EQUATORWARD ENTRANCE REGION OF THE
UPPER LVL JET. THIS SUGGESTS S COASTAL AREAS COULD CONTINUE TO SEE
PRECIP...POSSIBLY EVEN CHANGING BACK TO SNOW FOR A TIME WELL INTO
THE DAY ON THU. THE MORE PROGRESSIVE GUIDANCE...LED BY THE GFS
WOULD MOVE BOTH OF THESE FEATURES OFFSHORE SUCH THAT THU IS
MAINLY DRY AND BECOMING QUITE COLD AS ANOTHER ARCTIC AIRMASS
SETTLES IN. FOR NOW...WILL CONTINUE TO LEAN ON THE MORE
PROGRESSIVE GFS BUT WITH THE ECENS/GEFS SLOWER MEMBERS BLENDED IN.
THE FINAL ANSWER WILL LIKELY BE SOMEWHERE IN BETWEEN THE TWO
SOLUTIONS. IN ANY CASE...MUCH COLDER AIRMASS EXPECTED TO MOVE IN.

THU NIGHT INTO FRI NIGHT...
COLD AIRMASS ACROSS THE REGION ASSOCIATED WITH YET ANOTHER 1035+
HPA HIGH PRES. WILL LIKELY SEE HIGHS ONLY MAKING THE TEENS AND 20S
WITH LOWS BACK IN THE SINGLE DIGITS ABOVE AND BELOW ZERO.

NEXT WEEKEND...
SOME UNCERTAINTY HERE AS TO WHETHER YET ANOTHER WAVE WILL BE
EFFECT THE REGION. WILL LEAN MAINLY DRY FOR NOW AS THE AIRMASS IN
PLACE IS QUITE DRY AND THE WAVE ITSELF IS QUITE WEAK AND SHEARING
OUT.

&&

.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TODAY AND TONIGHT/...

TODAY AND TONIGHT...MODERATE CONFIDENCE.  VFR CONDITIONS THROUGH AT
LEAST MID MORNING.  SOME MVFR TO IFR CONDITIONS DEVELOP FROM WEST TO
EAST LATE THIS MORNING AND THIS AFTERNOON IN AREAS OF LIGHT SNOW.
HOWEVER...THE BULK OF THE MODERATE TO EVEN BRIEFLY HEAVY SNOW WILL
OCCUR THIS EVENING WHEN WIDESPREAD IFR TO LIFR CONDITIONS OCCUR.
THE LOWER CONDITIONS MOST LIKELY SOUTH OF THE MA TURNPIKE.  PTYPE
PRETTY MUCH ALL SNOW...EXCEPT FOR THE VERY IMMEDIATE SOUTH
COAST/CAPE WHERE SNOW MAY MIX WITH OR CHANGE TO RAIN FOR A TIME.
WHETHER OR NOT THAT HAPPENS IS UNCERTAIN...BUT WE DO THINK THAT AT
LEAST THE ISLANDS WILL CHANGE TO RAIN.

BULK OF SNOW ENDS BY 8 OR 9Z TONIGHT AND MUCH OF THE THE REGION
SHOULD ALREADY HAVE VFR CONDITIONS BY 12Z MONDAY.

KBOS TAF...CONFIDENT IN OVERALL TRENDS BUT EXACT TIMING IS MORE
UNCERTAIN.  WHILE SOME LIGHT SNOW IS POSSIBLE THIS
AFTERNOON...BULK OF ACCUMULATING SNOW WITH WIDESPREAD IFR TO LIFR
CONDITIONS EXPECTED THIS EVENING.

KBDL TAF...CONFIDENT IN OVERALL TRENDS BUT EXACT TIMING IS MORE
UNCERTAIN.  WHILE SOME LIGHT SNOW IS POSSIBLE LATE THIS MORNING AND
AFTERNOON...BULK OF ACCUMULATING SNOW WITH WIDESPREAD IFR TO LIFR
CONDITIONS EXPECTED AFTER 3 OR 4 PM.

OUTLOOK...MONDAY THROUGH THURSDAY...

MONDAY...HIGH CONFIDENCE.
IFR/MVFR IN REMNANT SNOWS END EARLY...WITH TRANSITION TO VFR
EVERYWHERE BY AFTERNOON. W-NW WIND GUSTS UP TO AROUND 30 KT AT
TIMES DURING THE AFTERNOON AND EVENING.

MON NIGHT INTO TUE...HIGH CONFIDENCE.
MAINLY VFR. WINDS DIMINISH MON NIGHT.

TUE NIGHT INTO THU...MODERATE CONFIDENCE.
A MESSY PERIOD. SNOW BEGINS EVERYWHERE LATE TUE INTO WED NIGHT
WITH MODERATE ACCUMS POSSIBLE...THEN EXPECT GRADUALLY TRANSITION
TO SLEET AND FREEZING RAIN DURING THE EARLY MORNING HOURS
WED...THEN TO ALL RAIN DURING THE DAY ON WED. SOME ICE ACCUM
POSSIBLE AS WELL. THE RAIN DIMINISHES LATE WED BUT MAY LINGER
ALONG THE S COAST AND EVEN CHANGE TO SNOW INTO THE DAY ON THU.
EXPECT PERIODS OF IFR/LIFR CONDITIONS THROUGHOUT THE PERIOD WITH
SOME IMPROVEMENT FROM N-S ON THU. LLWS LIKELY ESPECIALLY TUE NIGHT
AND EARLY WED.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TODAY AND TONIGHT/...HIGH CONFIDENCE.

A WEAK WAVE OF LOW PRESSURE MOVES ACROSS THE WATERS LATER
TODAY AND TONIGHT.  WEAK PRESSURE GRADIENT SHOULD KEEP
WINDS/SEAS BELOW SMALL CRAFT THRESHOLDS TODAY AND TONIGHT.  THE
SYSTEM REALLY INTENSIFIES AS IT MOVES INTO THE CANADIAN MARITIMES
NEAR DAYBREAK MONDAY...SO WESTERLY WIND GUSTS MAY REACH 20 TO 25
KNOTS NEAR 12Z MONDAY.  OTHERWISE...RAIN AND SNOW LATE TODAY AND
ESPECIALLY TONIGHT WILL REDUCE VISIBILITIES AT TIMES FOR MARINERS.

OUTLOOK...MONDAY THROUGH THURSDAY..MODERATE CONFIDENCE.

MONDAY INTO MONDAY NIGHT...HIGH CONFIDENCE.
WINDS BEGIN OUT OF THE SW THEN SHIFT TO W-NW IN THE AFTERNOON.
WIND GUSTS REACH 35-40 KT DURING THE AFTERNOON AND OVERNIGHT SO
WILL BE ISSUING A GALE WATCH. SEAS BUILD 10-12 FT ON THE OCEAN
WATERS. SOME LIGHT FREEZING SPRAY POSSIBLE MON EVENING INTO TUE
MORNING.

TUE...HIGH CONFIDENCE.
WINDS AND SEAS START AT OR AROUND SMALL CRAFT ADVISORY THRESHOLDS
BUT THEN DROP DURING THE DAY SUCH THAT A PERIOD OF QUIET BOATING
WEATHER IS LIKELY TUE AFTERNOON AND EVENING.

TUE NIGHT INTO THU...MODERATE CONFIDENCE.
LOW PRES PASSES WELL INLAND...WITH WINDS OUT OF THE S GRADUALLY
SHIFTING TO THE W LATE WED INTO THU. PERIODS OF WIND GUSTS 25-30
KT EXPECTED ALTHOUGH GUSTS MAY APPROACH GALE FORCE WED EVENING.
SEAS BUILD THROUGH WED TO AROUND 7-10FT ON THE OCEAN WATERS THEN
DIMINISH THU. AT THE VERY LEAST SMALL CRAFT ADVISORIES ARE LIKELY
DURING THIS PERIOD. PERIODS OF SNOW CHANGING TO RAIN EARLY WED
WITH SOME LOW VSBYS IN RAIN AND FOG ON WED.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WINTER WEATHER ADVISORY FROM NOON TODAY TO 7 AM EST MONDAY FOR
     CTZ002>004.
MA...WINTER WEATHER ADVISORY FROM NOON TODAY TO 7 AM EST MONDAY FOR
     MAZ002>016-022>024-026.
     WINTER STORM WARNING FROM 3 PM THIS AFTERNOON TO 7 AM EST
     MONDAY FOR MAZ017>021.
RI...WINTER WEATHER ADVISORY FROM NOON TODAY TO 7 AM EST MONDAY FOR
     RIZ001-008.
     WINTER STORM WARNING FROM 3 PM THIS AFTERNOON TO 7 AM EST
     MONDAY FOR RIZ002>007.
MARINE...GALE WATCH FROM MONDAY MORNING THROUGH LATE MONDAY NIGHT FOR
     ANZ231>235-237-250-251-254>256.

&&

$$
SYNOPSIS...FRANK/DOODY
NEAR TERM...FRANK
SHORT TERM...FRANK
LONG TERM...DOODY
AVIATION...FRANK/DOODY
MARINE...FRANK/DOODY




000
FXUS61 KBOX 010958
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
458 AM EST SUN MAR 1 2015

.SYNOPSIS...
A FAST MOVING LOW PRESSURE SYSTEM WILL BRING ACCUMULATING SNOW
LATER TODAY AND ESPECIALLY TONIGHT WITH THE HIGHEST AMOUNTS
EXPECTED SOUTH OF THE MASSACHUSETTS TURNPIKE.HIGH PRESSURE BRINGS
DRY COLD AIR FOR THE EARLY WEEK. LOW PRESSURE FROM NORTHERN CANADA
AND ASSOCIATED LOW FORMING OVER THE PLAINS MONDAY WILL
MERGE...THEN PASS WEST AND NORTH OF NEW ENGLAND. THIS WILL SWING A
COLD FRONT ACROSS THE REGION ON WEDNESDAY. DRY AND COLD WEATHER
RETURNS FOR THE END OF THE WEEK.

&&

.NEAR TERM /UNTIL 3 PM THIS AFTERNOON/...

MID LEVEL CLOUDINESS WILL STREAM INTO SOUTHERN NEW ENGLAND AND
THICKEN DURING THE MORNING HOURS IN ADVANCE OF APPROACHING LOW
PRESSURE.  SOUTHWEST FLOW ALOFT OVERRUNING THE COLD DOME AT THE
SURFACE MAY ALLOW FOR SOME LIGHT SNOW/FLURRIES TO BREAK
OUT ACROSS THE INTERIOR LATE THIS MORNING/EARLY AFTERNOON AND THEN
FIND THEIR WAY TO THE COAST BY MID TO LATE AFTERNOON.  THE LIFT
THROUGH MID AFTERNOON IS FAIRLY WEAK...SO THE AREAS OF SNOW SHOULD
BE RATHER LIGHT. ANY ACCUMULATIONS THAT OCCUR WILL PROBABLY BE
A DUSTING TO LESS THAN 1 INCH THROUGH THAT THAT TIME.  HIGH TEMPS
WILL MAINLY BE IN THE UPPER 20S TO AROUND 30.

&&

.SHORT TERM /3 PM THIS AFTERNOON THROUGH 6 AM MONDAY/...
*** BULK OF THE ACCUMULATING SNOW OCCURS BETWEEN 3 PM AND 1 AM WITH
  THE HEAVIEST AMOUNTS SOUTH OF THE MA TURNPIKE ***

1) OVERVIEW AND TIMING:

THE BULK OF THE ACCUMULATING SNOW WILL OCCUR BETWEEN 3 PM AND
1 AM ACROSS THE REGION.  THE SNOW SHOULD TAPER OFF TO FLURRIES
TOWARD DAYBREAK MONDAY.  THE MODELS DO AGREE THAT THE BETTER FORCING
WILL OCCUR TO THE SOUTH OF THE MA TURNPIKE.  THIS A RESULT
OF SECONDARY LOW PRESSURE NEAR THE SOUTH COAST...ALLOWING FOR
SOME SURFACE CONVERGENCE AS WELL AS THE INTENSIFICATION OF THE LOW
LEVEL JET.

THE BIGGEST ISSUE IS THE MODELS ARE NOT IN AGREEMENT IN HOW
INTENSE THE FORCING WILL BE ACROSS THE REGION THIS EVENING.  THE
RGEM/NAM ARE THE MOST ROBUST WITH QPF SOUTH OF THE MA TURNPIKE.  THE
NAM SHOWS A PERIOD OF FAIRLY STRONG LIFT OF 15 TO 20 MICROBARS PER
SECOND WITHIN THE BEST SNOWGROWTH REGION THIS EVENING.  THIS WOULD
TRANSLATE TO A PERIOD OF 1+ INCH PER HOUR SNOWFALL RATES NEAR AND
SOUTH OF THE MA PIKE.  ON THE OTHER HAND...THE GFS ALSO HAS FAIRLY
STRONG LIFT...BUT KEEPS IT SOUTHEAST OF OUR REGION OUT OVER THE
OCEAN.  THE SECONDARY LOW PRESSURE SYSTEM ON THE GFS IS WEAKER AND
FURTHER SOUTHEAST...RESULTING IN THE LOW LEVEL JET BEING DISPLACED
FURTHER EAST.  THE ECMWF/UKMET SOLUTIONS SEEM TO BE THE MIDDLE
GROUND WHICH WE WILL LEAN TOWARDS.

2) WINTER WEATHER HEADLINES AND SNOW ACCUMS:

WITH THAT SAID...THE OTHER DILEMMA IS WHAT TO DO WITH THE CURRENT
HEADLINES.  THIS DOES NOT APPEAR TO BE THE TYPE OF SETUP WHERE WE
ARE GOING TO RECEIVE WIDESPREAD WARNING SNOWFALL AMOUNTS.  THE
WINDOW FOR THE VERY STRONG LIFT/FORCING IS SHORT-LIVED AND REALLY
WOULD LIKE TO SEE THE LOW LEVEL JET A BIT MORE BACKED TO TRANSPORT
DEEPER MOISTURE NORTHWARD.  THEREFORE...FEEL THAT FOR MOST OF THE
REGION WINTER WEATHER ADVISORY/S FOR 3 TO 6 INCHES OF SNOW WILL
COVER IT.  HOWEVER...GIVEN THERE IS NICE OMEGA IN THE SNOW GROWTH
REGION...WE MIGHT BE LOOKING AT SOME DECENT RATIOS.  SO WE STILL CAN
NOT RULE OUT THE LOW RISK OF REACHING WARNING AMOUNTS AND LATER
SHIFTS WILL HAVE TO MONITOR CLOSELY...ESPECIALLY ACROSS NORTHERN CT
AND NORTHWEST RI.

WE DID UPGRADE A SMALL AREA FROM CENTRAL AND SOUTHERN RHODE ISLAND
INTO SOUTHEAST MA INCLUDING THE SOUTH COAST TO A WINTER
STORM WARNING.  THE NOSE OF THE LOW LEVEL JET LOOKS TO TRANSPORT
SOME DEEPER MOISTURE INTO THIS REGION.  THERE ALSO COULD BE SOME
ENHANCEMENT ALONG THE LAND/SEA INTERFACE AND A WEAK SURFACE
BOUNDARY SO WENT WITH 4 TO 8 INCHES IN THIS REGION.

3) PTYPE AND IMPACTS:

THE MODELS HAVE TRENDED COLDER OVER THE PAST 24 HOURS.
THEREFORE...EXPECT THIS BE PRETTY MUCH A SNOW EVENT.  IT DOES BECOME
A VERY CLOSE CALL NEAR THE SOUTH COAST...BUT WERE LEANING TOWARDS IT
STAYING MAINLY WET SNOW.  IF PRECIPITATION LIGHTENS UP THAT MAY
INCREASE THIS RISK WE SEE A BRIEF CHANGE OVER TO RAIN.
MEANWHILE...WE WENT WITH A HIGH END WINTER WEATHER ADVISORY FOR THE
CAPE BECAUSE THEY MAY CHANGE TO RAIN FOR A TIME...ESPECIALLY EAST OF
HYANNIS.  IF THE CHANGE OVER DOES NOT OCCUR...WE MAY NEED TO UPGRADE
THEM TO A WINTER STORM WARNING ESPECIALLY NEAR THE CAPE COD CANAL
GIVEN EXPECTED QPF.

THE ONE THING WILL ALSO HAVE TO WATCH IS AREAS NEAR THE SOUTH COAST
AND CAPE COD.  LOOKS TO BE A WET SNOW DOWN THAT WAY AND ON GOING
ROOF ISSUES MAY BE EXACERBATED...ESPECIALLY IF ANY AREAS THAT ARE
ABLE TO EXCEED 6 INCHES OF WET SNOW.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
HIGHLIGHTS...

  * BLUSTERY CONDITIONS ON MON WITH DRY WEATHER CONTINUING INTO
    TUE.
  * A STORM SYSTEM BRINGS MIXED PRECIP TUE INTO WED.
  * CONDITIONS IMPROVE THU BUT BECOMING COLD AGAIN.

OVERVIEW AND MODEL PREFERENCES...
A SPLIT FLOW MERGER WILL BE THE DEFINING FACTOR THROUGH THE LONG
TERM FORECAST PERIOD. IN THE MID TERM...THE STREAMS MERGE THANKS
TO PHASING OF NRN AND SRN STREAM SHORTWAVES UPSTREAM AS MERGING
STRONG JET DEVELOPS ACROSS THE NE CONUS. THESE FEATURES WILL ALLOW
LOW PRES TO GRADUALLY DEEPEN AND SLIDE THROUGH SRN ONTARIO AND
QUEBEC...CREATING AN OVERRUNNING EVENT AS THE SYSTEM ATTEMPTS TO
OCCLUDE. THIS IS THE MIXED PRECIP EVENT WE HAVE BEEN DISCUSSING
FOR SOME TIME NOW. NOW THAT NAM HAS CAPTURED IT...IT APPEARS
COLDER THAN MOST OF THE DETERMINISTIC GUIDANCE...WHILE THE ECMWF
STARTS COLD AND SHIFTS TO THE WARMER SIDE OF THE ENVELOPE DUE TO
THE FACT THAT IT IS MORE AMPLIFIED THAN OTHER MODELS. THE
GFS...ECENS/GEFS MEANS ARE ACTUALLY A GOOD MIDDLE GROUND HERE.
THIS BLEND WILL BE USED THROUGH THE REMAINDER OF THE LONG TERM AS
WELL TO TAKE INTO ACCOUNT THE VARIOUS SOLUTIONS.

DETAILS...

MON INTO TUE...
REMNANT SNOWFALLS WILL BE GRADUALLY COMING TO AN END THROUGH MID
MORNING MON...ALTHOUGH FLURRIES MAY LINGER A BIT LONGER IN THE
BERKSHIRES. STRONG HIGH PRES WILL THEN SLIDE ACROSS THE REGION
THROUGH TUE...WITH MAINLY DRY WX. TEMPS LOOK TO REMAIN BELOW
NORMAL GIVEN LITTLE CHANGE IN THE AIRMASS FROM PREVIOUS DAYS.

TUE NIGHT INTO WED...
OVERRUNNING EVENT EXPECTED AS WARM FRONT WILL ATTEMPT TO PUSH N
ACROSS THE REGION BUT IS LIKELY TO STRUGGLE NEAR THE SFC DUE TO
ENTRENCHED COLD AIR AND A DEEP SNOWPACK. HOWEVER...50-60 KT LLJ
WITH STRONG SLY COMPONENT WILL ALLOW UPPER LVL WARMING TON
CONTINUE UNIMPEDED. IN SPITE OF THE STRONG JET AT ONLY 3-5KFT
ABOVE THE SFC...SNOWPACK WILL MAKE MIXING DIFFICULT SO NOT
EXPECTING SIGNIFICANT WIND ISSUES AT THIS TIME.

THE COLUMN STARTS COLD ENOUGH FOR SNOW AT ONSET TUE EVENING...AND
LOOKS LIKE AS MUCH AS 0.40-0.60 OF THE TOTAL EVENT QPF FALLS AS
SNOW INITIALLY EVERYWHERE...WITH GRADUAL CHANGEOVER DURING THE
EARLY MORNING HOURS WED MORNING FROM S-N. THEREFORE...COULD SEE AT
LEAST ADVISORY IF NOT LOW-END WARNING LVL SNOWFALLS THROUGH THE
OVERNIGHT HOURS BEFORE A TRANSITION TO SLEET...THEN FREEZING RAIN.
FREEZING RAIN COULD LOCK IN FOR SOME TIME AND GIVEN THAT H93 TEMPS
/EVEN ON THE COLDEST GUIDANCE/ AN AVERAGE OF +4C DURING THE 08Z-
16Z TIMEFRAME...BUT SFC TEMPS MAY HOLD NEAR FREEZING FOR SOME TIME
GIVEN THE DEEP SNOWPACK ACROSS THE AREA. HOWEVER...STRAIGHT RAIN
FOR A TIME FROM ABOUT MID MORNING INTO THE AFTERNOON IS LIKELY
UNTIL THE PRECIP COMES TO AN END. DEPENDING ON HOW QUICKLY 2M
TEMPS REBOUND...AS MUCH AS A QUARTER INCH OF ICE CAN/T BE RULED
OUT. AGREE WITH PREVIOUS FORECASTER THAT LEANING A BIT COLDER THAN
MOS 2M TEMPS IS PROBABLY THE WAY TO GO.

MODEST UPPER LVL INSTABILITY AS WARMING OCCURS IN THE MID LVLS
COULD ALSO MEAN A PERIOD OF HEAVY PRECIP...BOTH SNOW AND RAIN.
WITH THE RAIN...COMES A RISK FOR POOR DRAINAGE FLOODING ACROSS THE
REGION AS SNOW MELTS AND DRAINS BECOME CLOGGED. PRECIP COMES TO AN
END ACROSS MOST OF THE REGION BY AFTERNOON WED...BUT MAY LINGER A
BIT NEAR THE S COAST...MORE ON THAT BELOW.

WED NIGHT INTO THU...
CONFIDENCE IN THE FORECAST CONTINUES TO DIMINISH HERE PARTIALLY
DEPENDENT ON HOW FAST THE UPPER LVL JET EXITS TO THE EAST AND HOW
AMPLIFIED THE PATTERN REMAINS IN THE WAKE OF THE LOW PRES. THE
MORE AMPLIFIED GUIDANCE...LED BY THE ECMWF KEEPS THE COLD FRONT
JUST OFFSHORE AND WITHIN THE EQUATORWARD ENTRANCE REGION OF THE
UPPER LVL JET. THIS SUGGESTS S COASTAL AREAS COULD CONTINUE TO SEE
PRECIP...POSSIBLY EVEN CHANGING BACK TO SNOW FOR A TIME WELL INTO
THE DAY ON THU. THE MORE PROGRESSIVE GUIDANCE...LED BY THE GFS
WOULD MOVE BOTH OF THESE FEATURES OFFSHORE SUCH THAT THU IS
MAINLY DRY AND BECOMING QUITE COLD AS ANOTHER ARCTIC AIRMASS
SETTLES IN. FOR NOW...WILL CONTINUE TO LEAN ON THE MORE
PROGRESSIVE GFS BUT WITH THE ECENS/GEFS SLOWER MEMBERS BLENDED IN.
THE FINAL ANSWER WILL LIKELY BE SOMEWHERE IN BETWEEN THE TWO
SOLUTIONS. IN ANY CASE...MUCH COLDER AIRMASS EXPECTED TO MOVE IN.

THU NIGHT INTO FRI NIGHT...
COLD AIRMASS ACROSS THE REGION ASSOCIATED WITH YET ANOTHER 1035+
HPA HIGH PRES. WILL LIKELY SEE HIGHS ONLY MAKING THE TEENS AND 20S
WITH LOWS BACK IN THE SINGLE DIGITS ABOVE AND BELOW ZERO.

NEXT WEEKEND...
SOME UNCERTAINTY HERE AS TO WHETHER YET ANOTHER WAVE WILL BE
EFFECT THE REGION. WILL LEAN MAINLY DRY FOR NOW AS THE AIRMASS IN
PLACE IS QUITE DRY AND THE WAVE ITSELF IS QUITE WEAK AND SHEARING
OUT.

&&

.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TODAY AND TONIGHT/...

TODAY AND TONIGHT...MODERATE CONFIDENCE.  VFR CONDITIONS THROUGH AT
LEAST MID MORNING.  SOME MVFR TO IFR CONDITIONS DEVELOP FROM WEST TO
EAST LATE THIS MORNING AND THIS AFTERNOON IN AREAS OF LIGHT SNOW.
HOWEVER...THE BULK OF THE MODERATE TO EVEN BRIEFLY HEAVY SNOW WILL
OCCUR THIS EVENING WHEN WIDESPREAD IFR TO LIFR CONDITIONS OCCUR.
THE LOWER CONDITIONS MOST LIKELY SOUTH OF THE MA TURNPIKE.  PTYPE
PRETTY MUCH ALL SNOW...EXCEPT FOR THE VERY IMMEDIATE SOUTH
COAST/CAPE WHERE SNOW MAY MIX WITH OR CHANGE TO RAIN FOR A TIME.
WHETHER OR NOT THAT HAPPENS IS UNCERTAIN...BUT WE DO THINK THAT AT
LEAST THE ISLANDS WILL CHANGE TO RAIN.

BULK OF SNOW ENDS BY 8 OR 9Z TONIGHT AND MUCH OF THE THE REGION
SHOULD ALREADY HAVE VFR CONDITIONS BY 12Z MONDAY.

KBOS TAF...CONFIDENT IN OVERALL TRENDS BUT EXACT TIMING IS MORE
UNCERTAIN.  WHILE SOME LIGHT SNOW IS POSSIBLE THIS
AFTERNOON...BULK OF ACCUMULATING SNOW WITH WIDESPREAD IFR TO LIFR
CONDITIONS EXPECTED THIS EVENING.

KBDL TAF...CONFIDENT IN OVERALL TRENDS BUT EXACT TIMING IS MORE
UNCERTAIN.  WHILE SOME LIGHT SNOW IS POSSIBLE LATE THIS MORNING AND
AFTERNOON...BULK OF ACCUMULATING SNOW WITH WIDESPREAD IFR TO LIFR
CONDITIONS EXPECTED AFTER 3 OR 4 PM.

OUTLOOK...MONDAY THROUGH THURSDAY...

MONDAY...HIGH CONFIDENCE.
IFR/MVFR IN REMNANT SNOWS END EARLY...WITH TRANSITION TO VFR
EVERYWHERE BY AFTERNOON. W-NW WIND GUSTS UP TO AROUND 30 KT AT
TIMES DURING THE AFTERNOON AND EVENING.

MON NIGHT INTO TUE...HIGH CONFIDENCE.
MAINLY VFR. WINDS DIMINISH MON NIGHT.

TUE NIGHT INTO THU...MODERATE CONFIDENCE.
A MESSY PERIOD. SNOW BEGINS EVERYWHERE LATE TUE INTO WED NIGHT
WITH MODERATE ACCUMS POSSIBLE...THEN EXPECT GRADUALLY TRANSITION
TO SLEET AND FREEZING RAIN DURING THE EARLY MORNING HOURS
WED...THEN TO ALL RAIN DURING THE DAY ON WED. SOME ICE ACCUM
POSSIBLE AS WELL. THE RAIN DIMINISHES LATE WED BUT MAY LINGER
ALONG THE S COAST AND EVEN CHANGE TO SNOW INTO THE DAY ON THU.
EXPECT PERIODS OF IFR/LIFR CONDITIONS THROUGHOUT THE PERIOD WITH
SOME IMPROVEMENT FROM N-S ON THU. LLWS LIKELY ESPECIALLY TUE NIGHT
AND EARLY WED.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TODAY AND TONIGHT/...HIGH CONFIDENCE.

A WEAK WAVE OF LOW PRESSURE MOVES ACROSS THE WATERS LATER
TODAY AND TONIGHT.  WEAK PRESSURE GRADIENT SHOULD KEEP
WINDS/SEAS BELOW SMALL CRAFT THRESHOLDS TODAY AND TONIGHT.  THE
SYSTEM REALLY INTENSIFIES AS IT MOVES INTO THE CANADIAN MARITIMES
NEAR DAYBREAK MONDAY...SO WESTERLY WIND GUSTS MAY REACH 20 TO 25
KNOTS NEAR 12Z MONDAY.  OTHERWISE...RAIN AND SNOW LATE TODAY AND
ESPECIALLY TONIGHT WILL REDUCE VISIBILITIES AT TIMES FOR MARINERS.

OUTLOOK...MONDAY THROUGH THURSDAY..MODERATE CONFIDENCE.

MONDAY INTO MONDAY NIGHT...HIGH CONFIDENCE.
WINDS BEGIN OUT OF THE SW THEN SHIFT TO W-NW IN THE AFTERNOON.
WIND GUSTS REACH 35-40 KT DURING THE AFTERNOON AND OVERNIGHT SO
WILL BE ISSUING A GALE WATCH. SEAS BUILD 10-12 FT ON THE OCEAN
WATERS. SOME LIGHT FREEZING SPRAY POSSIBLE MON EVENING INTO TUE
MORNING.

TUE...HIGH CONFIDENCE.
WINDS AND SEAS START AT OR AROUND SMALL CRAFT ADVISORY THRESHOLDS
BUT THEN DROP DURING THE DAY SUCH THAT A PERIOD OF QUIET BOATING
WEATHER IS LIKELY TUE AFTERNOON AND EVENING.

TUE NIGHT INTO THU...MODERATE CONFIDENCE.
LOW PRES PASSES WELL INLAND...WITH WINDS OUT OF THE S GRADUALLY
SHIFTING TO THE W LATE WED INTO THU. PERIODS OF WIND GUSTS 25-30
KT EXPECTED ALTHOUGH GUSTS MAY APPROACH GALE FORCE WED EVENING.
SEAS BUILD THROUGH WED TO AROUND 7-10FT ON THE OCEAN WATERS THEN
DIMINISH THU. AT THE VERY LEAST SMALL CRAFT ADVISORIES ARE LIKELY
DURING THIS PERIOD. PERIODS OF SNOW CHANGING TO RAIN EARLY WED
WITH SOME LOW VSBYS IN RAIN AND FOG ON WED.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WINTER WEATHER ADVISORY FROM NOON TODAY TO 7 AM EST MONDAY FOR
     CTZ002>004.
MA...WINTER WEATHER ADVISORY FROM NOON TODAY TO 7 AM EST MONDAY FOR
     MAZ002>016-022>024-026.
     WINTER STORM WARNING FROM 3 PM THIS AFTERNOON TO 7 AM EST
     MONDAY FOR MAZ017>021.
RI...WINTER WEATHER ADVISORY FROM NOON TODAY TO 7 AM EST MONDAY FOR
     RIZ001-008.
     WINTER STORM WARNING FROM 3 PM THIS AFTERNOON TO 7 AM EST
     MONDAY FOR RIZ002>007.
MARINE...GALE WATCH FROM MONDAY MORNING THROUGH LATE MONDAY NIGHT FOR
     ANZ231>235-237-250-251-254>256.

&&

$$
SYNOPSIS...FRANK/DOODY
NEAR TERM...FRANK
SHORT TERM...FRANK
LONG TERM...DOODY
AVIATION...FRANK/DOODY
MARINE...FRANK/DOODY




000
FXUS61 KBOX 010958
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
458 AM EST SUN MAR 1 2015

.SYNOPSIS...
A FAST MOVING LOW PRESSURE SYSTEM WILL BRING ACCUMULATING SNOW
LATER TODAY AND ESPECIALLY TONIGHT WITH THE HIGHEST AMOUNTS
EXPECTED SOUTH OF THE MASSACHUSETTS TURNPIKE.HIGH PRESSURE BRINGS
DRY COLD AIR FOR THE EARLY WEEK. LOW PRESSURE FROM NORTHERN CANADA
AND ASSOCIATED LOW FORMING OVER THE PLAINS MONDAY WILL
MERGE...THEN PASS WEST AND NORTH OF NEW ENGLAND. THIS WILL SWING A
COLD FRONT ACROSS THE REGION ON WEDNESDAY. DRY AND COLD WEATHER
RETURNS FOR THE END OF THE WEEK.

&&

.NEAR TERM /UNTIL 3 PM THIS AFTERNOON/...

MID LEVEL CLOUDINESS WILL STREAM INTO SOUTHERN NEW ENGLAND AND
THICKEN DURING THE MORNING HOURS IN ADVANCE OF APPROACHING LOW
PRESSURE.  SOUTHWEST FLOW ALOFT OVERRUNING THE COLD DOME AT THE
SURFACE MAY ALLOW FOR SOME LIGHT SNOW/FLURRIES TO BREAK
OUT ACROSS THE INTERIOR LATE THIS MORNING/EARLY AFTERNOON AND THEN
FIND THEIR WAY TO THE COAST BY MID TO LATE AFTERNOON.  THE LIFT
THROUGH MID AFTERNOON IS FAIRLY WEAK...SO THE AREAS OF SNOW SHOULD
BE RATHER LIGHT. ANY ACCUMULATIONS THAT OCCUR WILL PROBABLY BE
A DUSTING TO LESS THAN 1 INCH THROUGH THAT THAT TIME.  HIGH TEMPS
WILL MAINLY BE IN THE UPPER 20S TO AROUND 30.

&&

.SHORT TERM /3 PM THIS AFTERNOON THROUGH 6 AM MONDAY/...
*** BULK OF THE ACCUMULATING SNOW OCCURS BETWEEN 3 PM AND 1 AM WITH
  THE HEAVIEST AMOUNTS SOUTH OF THE MA TURNPIKE ***

1) OVERVIEW AND TIMING:

THE BULK OF THE ACCUMULATING SNOW WILL OCCUR BETWEEN 3 PM AND
1 AM ACROSS THE REGION.  THE SNOW SHOULD TAPER OFF TO FLURRIES
TOWARD DAYBREAK MONDAY.  THE MODELS DO AGREE THAT THE BETTER FORCING
WILL OCCUR TO THE SOUTH OF THE MA TURNPIKE.  THIS A RESULT
OF SECONDARY LOW PRESSURE NEAR THE SOUTH COAST...ALLOWING FOR
SOME SURFACE CONVERGENCE AS WELL AS THE INTENSIFICATION OF THE LOW
LEVEL JET.

THE BIGGEST ISSUE IS THE MODELS ARE NOT IN AGREEMENT IN HOW
INTENSE THE FORCING WILL BE ACROSS THE REGION THIS EVENING.  THE
RGEM/NAM ARE THE MOST ROBUST WITH QPF SOUTH OF THE MA TURNPIKE.  THE
NAM SHOWS A PERIOD OF FAIRLY STRONG LIFT OF 15 TO 20 MICROBARS PER
SECOND WITHIN THE BEST SNOWGROWTH REGION THIS EVENING.  THIS WOULD
TRANSLATE TO A PERIOD OF 1+ INCH PER HOUR SNOWFALL RATES NEAR AND
SOUTH OF THE MA PIKE.  ON THE OTHER HAND...THE GFS ALSO HAS FAIRLY
STRONG LIFT...BUT KEEPS IT SOUTHEAST OF OUR REGION OUT OVER THE
OCEAN.  THE SECONDARY LOW PRESSURE SYSTEM ON THE GFS IS WEAKER AND
FURTHER SOUTHEAST...RESULTING IN THE LOW LEVEL JET BEING DISPLACED
FURTHER EAST.  THE ECMWF/UKMET SOLUTIONS SEEM TO BE THE MIDDLE
GROUND WHICH WE WILL LEAN TOWARDS.

2) WINTER WEATHER HEADLINES AND SNOW ACCUMS:

WITH THAT SAID...THE OTHER DILEMMA IS WHAT TO DO WITH THE CURRENT
HEADLINES.  THIS DOES NOT APPEAR TO BE THE TYPE OF SETUP WHERE WE
ARE GOING TO RECEIVE WIDESPREAD WARNING SNOWFALL AMOUNTS.  THE
WINDOW FOR THE VERY STRONG LIFT/FORCING IS SHORT-LIVED AND REALLY
WOULD LIKE TO SEE THE LOW LEVEL JET A BIT MORE BACKED TO TRANSPORT
DEEPER MOISTURE NORTHWARD.  THEREFORE...FEEL THAT FOR MOST OF THE
REGION WINTER WEATHER ADVISORY/S FOR 3 TO 6 INCHES OF SNOW WILL
COVER IT.  HOWEVER...GIVEN THERE IS NICE OMEGA IN THE SNOW GROWTH
REGION...WE MIGHT BE LOOKING AT SOME DECENT RATIOS.  SO WE STILL CAN
NOT RULE OUT THE LOW RISK OF REACHING WARNING AMOUNTS AND LATER
SHIFTS WILL HAVE TO MONITOR CLOSELY...ESPECIALLY ACROSS NORTHERN CT
AND NORTHWEST RI.

WE DID UPGRADE A SMALL AREA FROM CENTRAL AND SOUTHERN RHODE ISLAND
INTO SOUTHEAST MA INCLUDING THE SOUTH COAST TO A WINTER
STORM WARNING.  THE NOSE OF THE LOW LEVEL JET LOOKS TO TRANSPORT
SOME DEEPER MOISTURE INTO THIS REGION.  THERE ALSO COULD BE SOME
ENHANCEMENT ALONG THE LAND/SEA INTERFACE AND A WEAK SURFACE
BOUNDARY SO WENT WITH 4 TO 8 INCHES IN THIS REGION.

3) PTYPE AND IMPACTS:

THE MODELS HAVE TRENDED COLDER OVER THE PAST 24 HOURS.
THEREFORE...EXPECT THIS BE PRETTY MUCH A SNOW EVENT.  IT DOES BECOME
A VERY CLOSE CALL NEAR THE SOUTH COAST...BUT WERE LEANING TOWARDS IT
STAYING MAINLY WET SNOW.  IF PRECIPITATION LIGHTENS UP THAT MAY
INCREASE THIS RISK WE SEE A BRIEF CHANGE OVER TO RAIN.
MEANWHILE...WE WENT WITH A HIGH END WINTER WEATHER ADVISORY FOR THE
CAPE BECAUSE THEY MAY CHANGE TO RAIN FOR A TIME...ESPECIALLY EAST OF
HYANNIS.  IF THE CHANGE OVER DOES NOT OCCUR...WE MAY NEED TO UPGRADE
THEM TO A WINTER STORM WARNING ESPECIALLY NEAR THE CAPE COD CANAL
GIVEN EXPECTED QPF.

THE ONE THING WILL ALSO HAVE TO WATCH IS AREAS NEAR THE SOUTH COAST
AND CAPE COD.  LOOKS TO BE A WET SNOW DOWN THAT WAY AND ON GOING
ROOF ISSUES MAY BE EXACERBATED...ESPECIALLY IF ANY AREAS THAT ARE
ABLE TO EXCEED 6 INCHES OF WET SNOW.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
HIGHLIGHTS...

  * BLUSTERY CONDITIONS ON MON WITH DRY WEATHER CONTINUING INTO
    TUE.
  * A STORM SYSTEM BRINGS MIXED PRECIP TUE INTO WED.
  * CONDITIONS IMPROVE THU BUT BECOMING COLD AGAIN.

OVERVIEW AND MODEL PREFERENCES...
A SPLIT FLOW MERGER WILL BE THE DEFINING FACTOR THROUGH THE LONG
TERM FORECAST PERIOD. IN THE MID TERM...THE STREAMS MERGE THANKS
TO PHASING OF NRN AND SRN STREAM SHORTWAVES UPSTREAM AS MERGING
STRONG JET DEVELOPS ACROSS THE NE CONUS. THESE FEATURES WILL ALLOW
LOW PRES TO GRADUALLY DEEPEN AND SLIDE THROUGH SRN ONTARIO AND
QUEBEC...CREATING AN OVERRUNNING EVENT AS THE SYSTEM ATTEMPTS TO
OCCLUDE. THIS IS THE MIXED PRECIP EVENT WE HAVE BEEN DISCUSSING
FOR SOME TIME NOW. NOW THAT NAM HAS CAPTURED IT...IT APPEARS
COLDER THAN MOST OF THE DETERMINISTIC GUIDANCE...WHILE THE ECMWF
STARTS COLD AND SHIFTS TO THE WARMER SIDE OF THE ENVELOPE DUE TO
THE FACT THAT IT IS MORE AMPLIFIED THAN OTHER MODELS. THE
GFS...ECENS/GEFS MEANS ARE ACTUALLY A GOOD MIDDLE GROUND HERE.
THIS BLEND WILL BE USED THROUGH THE REMAINDER OF THE LONG TERM AS
WELL TO TAKE INTO ACCOUNT THE VARIOUS SOLUTIONS.

DETAILS...

MON INTO TUE...
REMNANT SNOWFALLS WILL BE GRADUALLY COMING TO AN END THROUGH MID
MORNING MON...ALTHOUGH FLURRIES MAY LINGER A BIT LONGER IN THE
BERKSHIRES. STRONG HIGH PRES WILL THEN SLIDE ACROSS THE REGION
THROUGH TUE...WITH MAINLY DRY WX. TEMPS LOOK TO REMAIN BELOW
NORMAL GIVEN LITTLE CHANGE IN THE AIRMASS FROM PREVIOUS DAYS.

TUE NIGHT INTO WED...
OVERRUNNING EVENT EXPECTED AS WARM FRONT WILL ATTEMPT TO PUSH N
ACROSS THE REGION BUT IS LIKELY TO STRUGGLE NEAR THE SFC DUE TO
ENTRENCHED COLD AIR AND A DEEP SNOWPACK. HOWEVER...50-60 KT LLJ
WITH STRONG SLY COMPONENT WILL ALLOW UPPER LVL WARMING TON
CONTINUE UNIMPEDED. IN SPITE OF THE STRONG JET AT ONLY 3-5KFT
ABOVE THE SFC...SNOWPACK WILL MAKE MIXING DIFFICULT SO NOT
EXPECTING SIGNIFICANT WIND ISSUES AT THIS TIME.

THE COLUMN STARTS COLD ENOUGH FOR SNOW AT ONSET TUE EVENING...AND
LOOKS LIKE AS MUCH AS 0.40-0.60 OF THE TOTAL EVENT QPF FALLS AS
SNOW INITIALLY EVERYWHERE...WITH GRADUAL CHANGEOVER DURING THE
EARLY MORNING HOURS WED MORNING FROM S-N. THEREFORE...COULD SEE AT
LEAST ADVISORY IF NOT LOW-END WARNING LVL SNOWFALLS THROUGH THE
OVERNIGHT HOURS BEFORE A TRANSITION TO SLEET...THEN FREEZING RAIN.
FREEZING RAIN COULD LOCK IN FOR SOME TIME AND GIVEN THAT H93 TEMPS
/EVEN ON THE COLDEST GUIDANCE/ AN AVERAGE OF +4C DURING THE 08Z-
16Z TIMEFRAME...BUT SFC TEMPS MAY HOLD NEAR FREEZING FOR SOME TIME
GIVEN THE DEEP SNOWPACK ACROSS THE AREA. HOWEVER...STRAIGHT RAIN
FOR A TIME FROM ABOUT MID MORNING INTO THE AFTERNOON IS LIKELY
UNTIL THE PRECIP COMES TO AN END. DEPENDING ON HOW QUICKLY 2M
TEMPS REBOUND...AS MUCH AS A QUARTER INCH OF ICE CAN/T BE RULED
OUT. AGREE WITH PREVIOUS FORECASTER THAT LEANING A BIT COLDER THAN
MOS 2M TEMPS IS PROBABLY THE WAY TO GO.

MODEST UPPER LVL INSTABILITY AS WARMING OCCURS IN THE MID LVLS
COULD ALSO MEAN A PERIOD OF HEAVY PRECIP...BOTH SNOW AND RAIN.
WITH THE RAIN...COMES A RISK FOR POOR DRAINAGE FLOODING ACROSS THE
REGION AS SNOW MELTS AND DRAINS BECOME CLOGGED. PRECIP COMES TO AN
END ACROSS MOST OF THE REGION BY AFTERNOON WED...BUT MAY LINGER A
BIT NEAR THE S COAST...MORE ON THAT BELOW.

WED NIGHT INTO THU...
CONFIDENCE IN THE FORECAST CONTINUES TO DIMINISH HERE PARTIALLY
DEPENDENT ON HOW FAST THE UPPER LVL JET EXITS TO THE EAST AND HOW
AMPLIFIED THE PATTERN REMAINS IN THE WAKE OF THE LOW PRES. THE
MORE AMPLIFIED GUIDANCE...LED BY THE ECMWF KEEPS THE COLD FRONT
JUST OFFSHORE AND WITHIN THE EQUATORWARD ENTRANCE REGION OF THE
UPPER LVL JET. THIS SUGGESTS S COASTAL AREAS COULD CONTINUE TO SEE
PRECIP...POSSIBLY EVEN CHANGING BACK TO SNOW FOR A TIME WELL INTO
THE DAY ON THU. THE MORE PROGRESSIVE GUIDANCE...LED BY THE GFS
WOULD MOVE BOTH OF THESE FEATURES OFFSHORE SUCH THAT THU IS
MAINLY DRY AND BECOMING QUITE COLD AS ANOTHER ARCTIC AIRMASS
SETTLES IN. FOR NOW...WILL CONTINUE TO LEAN ON THE MORE
PROGRESSIVE GFS BUT WITH THE ECENS/GEFS SLOWER MEMBERS BLENDED IN.
THE FINAL ANSWER WILL LIKELY BE SOMEWHERE IN BETWEEN THE TWO
SOLUTIONS. IN ANY CASE...MUCH COLDER AIRMASS EXPECTED TO MOVE IN.

THU NIGHT INTO FRI NIGHT...
COLD AIRMASS ACROSS THE REGION ASSOCIATED WITH YET ANOTHER 1035+
HPA HIGH PRES. WILL LIKELY SEE HIGHS ONLY MAKING THE TEENS AND 20S
WITH LOWS BACK IN THE SINGLE DIGITS ABOVE AND BELOW ZERO.

NEXT WEEKEND...
SOME UNCERTAINTY HERE AS TO WHETHER YET ANOTHER WAVE WILL BE
EFFECT THE REGION. WILL LEAN MAINLY DRY FOR NOW AS THE AIRMASS IN
PLACE IS QUITE DRY AND THE WAVE ITSELF IS QUITE WEAK AND SHEARING
OUT.

&&

.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TODAY AND TONIGHT/...

TODAY AND TONIGHT...MODERATE CONFIDENCE.  VFR CONDITIONS THROUGH AT
LEAST MID MORNING.  SOME MVFR TO IFR CONDITIONS DEVELOP FROM WEST TO
EAST LATE THIS MORNING AND THIS AFTERNOON IN AREAS OF LIGHT SNOW.
HOWEVER...THE BULK OF THE MODERATE TO EVEN BRIEFLY HEAVY SNOW WILL
OCCUR THIS EVENING WHEN WIDESPREAD IFR TO LIFR CONDITIONS OCCUR.
THE LOWER CONDITIONS MOST LIKELY SOUTH OF THE MA TURNPIKE.  PTYPE
PRETTY MUCH ALL SNOW...EXCEPT FOR THE VERY IMMEDIATE SOUTH
COAST/CAPE WHERE SNOW MAY MIX WITH OR CHANGE TO RAIN FOR A TIME.
WHETHER OR NOT THAT HAPPENS IS UNCERTAIN...BUT WE DO THINK THAT AT
LEAST THE ISLANDS WILL CHANGE TO RAIN.

BULK OF SNOW ENDS BY 8 OR 9Z TONIGHT AND MUCH OF THE THE REGION
SHOULD ALREADY HAVE VFR CONDITIONS BY 12Z MONDAY.

KBOS TAF...CONFIDENT IN OVERALL TRENDS BUT EXACT TIMING IS MORE
UNCERTAIN.  WHILE SOME LIGHT SNOW IS POSSIBLE THIS
AFTERNOON...BULK OF ACCUMULATING SNOW WITH WIDESPREAD IFR TO LIFR
CONDITIONS EXPECTED THIS EVENING.

KBDL TAF...CONFIDENT IN OVERALL TRENDS BUT EXACT TIMING IS MORE
UNCERTAIN.  WHILE SOME LIGHT SNOW IS POSSIBLE LATE THIS MORNING AND
AFTERNOON...BULK OF ACCUMULATING SNOW WITH WIDESPREAD IFR TO LIFR
CONDITIONS EXPECTED AFTER 3 OR 4 PM.

OUTLOOK...MONDAY THROUGH THURSDAY...

MONDAY...HIGH CONFIDENCE.
IFR/MVFR IN REMNANT SNOWS END EARLY...WITH TRANSITION TO VFR
EVERYWHERE BY AFTERNOON. W-NW WIND GUSTS UP TO AROUND 30 KT AT
TIMES DURING THE AFTERNOON AND EVENING.

MON NIGHT INTO TUE...HIGH CONFIDENCE.
MAINLY VFR. WINDS DIMINISH MON NIGHT.

TUE NIGHT INTO THU...MODERATE CONFIDENCE.
A MESSY PERIOD. SNOW BEGINS EVERYWHERE LATE TUE INTO WED NIGHT
WITH MODERATE ACCUMS POSSIBLE...THEN EXPECT GRADUALLY TRANSITION
TO SLEET AND FREEZING RAIN DURING THE EARLY MORNING HOURS
WED...THEN TO ALL RAIN DURING THE DAY ON WED. SOME ICE ACCUM
POSSIBLE AS WELL. THE RAIN DIMINISHES LATE WED BUT MAY LINGER
ALONG THE S COAST AND EVEN CHANGE TO SNOW INTO THE DAY ON THU.
EXPECT PERIODS OF IFR/LIFR CONDITIONS THROUGHOUT THE PERIOD WITH
SOME IMPROVEMENT FROM N-S ON THU. LLWS LIKELY ESPECIALLY TUE NIGHT
AND EARLY WED.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TODAY AND TONIGHT/...HIGH CONFIDENCE.

A WEAK WAVE OF LOW PRESSURE MOVES ACROSS THE WATERS LATER
TODAY AND TONIGHT.  WEAK PRESSURE GRADIENT SHOULD KEEP
WINDS/SEAS BELOW SMALL CRAFT THRESHOLDS TODAY AND TONIGHT.  THE
SYSTEM REALLY INTENSIFIES AS IT MOVES INTO THE CANADIAN MARITIMES
NEAR DAYBREAK MONDAY...SO WESTERLY WIND GUSTS MAY REACH 20 TO 25
KNOTS NEAR 12Z MONDAY.  OTHERWISE...RAIN AND SNOW LATE TODAY AND
ESPECIALLY TONIGHT WILL REDUCE VISIBILITIES AT TIMES FOR MARINERS.

OUTLOOK...MONDAY THROUGH THURSDAY..MODERATE CONFIDENCE.

MONDAY INTO MONDAY NIGHT...HIGH CONFIDENCE.
WINDS BEGIN OUT OF THE SW THEN SHIFT TO W-NW IN THE AFTERNOON.
WIND GUSTS REACH 35-40 KT DURING THE AFTERNOON AND OVERNIGHT SO
WILL BE ISSUING A GALE WATCH. SEAS BUILD 10-12 FT ON THE OCEAN
WATERS. SOME LIGHT FREEZING SPRAY POSSIBLE MON EVENING INTO TUE
MORNING.

TUE...HIGH CONFIDENCE.
WINDS AND SEAS START AT OR AROUND SMALL CRAFT ADVISORY THRESHOLDS
BUT THEN DROP DURING THE DAY SUCH THAT A PERIOD OF QUIET BOATING
WEATHER IS LIKELY TUE AFTERNOON AND EVENING.

TUE NIGHT INTO THU...MODERATE CONFIDENCE.
LOW PRES PASSES WELL INLAND...WITH WINDS OUT OF THE S GRADUALLY
SHIFTING TO THE W LATE WED INTO THU. PERIODS OF WIND GUSTS 25-30
KT EXPECTED ALTHOUGH GUSTS MAY APPROACH GALE FORCE WED EVENING.
SEAS BUILD THROUGH WED TO AROUND 7-10FT ON THE OCEAN WATERS THEN
DIMINISH THU. AT THE VERY LEAST SMALL CRAFT ADVISORIES ARE LIKELY
DURING THIS PERIOD. PERIODS OF SNOW CHANGING TO RAIN EARLY WED
WITH SOME LOW VSBYS IN RAIN AND FOG ON WED.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WINTER WEATHER ADVISORY FROM NOON TODAY TO 7 AM EST MONDAY FOR
     CTZ002>004.
MA...WINTER WEATHER ADVISORY FROM NOON TODAY TO 7 AM EST MONDAY FOR
     MAZ002>016-022>024-026.
     WINTER STORM WARNING FROM 3 PM THIS AFTERNOON TO 7 AM EST
     MONDAY FOR MAZ017>021.
RI...WINTER WEATHER ADVISORY FROM NOON TODAY TO 7 AM EST MONDAY FOR
     RIZ001-008.
     WINTER STORM WARNING FROM 3 PM THIS AFTERNOON TO 7 AM EST
     MONDAY FOR RIZ002>007.
MARINE...GALE WATCH FROM MONDAY MORNING THROUGH LATE MONDAY NIGHT FOR
     ANZ231>235-237-250-251-254>256.

&&

$$
SYNOPSIS...FRANK/DOODY
NEAR TERM...FRANK
SHORT TERM...FRANK
LONG TERM...DOODY
AVIATION...FRANK/DOODY
MARINE...FRANK/DOODY




000
FXUS61 KBOX 010958
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
458 AM EST SUN MAR 1 2015

.SYNOPSIS...
A FAST MOVING LOW PRESSURE SYSTEM WILL BRING ACCUMULATING SNOW
LATER TODAY AND ESPECIALLY TONIGHT WITH THE HIGHEST AMOUNTS
EXPECTED SOUTH OF THE MASSACHUSETTS TURNPIKE.HIGH PRESSURE BRINGS
DRY COLD AIR FOR THE EARLY WEEK. LOW PRESSURE FROM NORTHERN CANADA
AND ASSOCIATED LOW FORMING OVER THE PLAINS MONDAY WILL
MERGE...THEN PASS WEST AND NORTH OF NEW ENGLAND. THIS WILL SWING A
COLD FRONT ACROSS THE REGION ON WEDNESDAY. DRY AND COLD WEATHER
RETURNS FOR THE END OF THE WEEK.

&&

.NEAR TERM /UNTIL 3 PM THIS AFTERNOON/...

MID LEVEL CLOUDINESS WILL STREAM INTO SOUTHERN NEW ENGLAND AND
THICKEN DURING THE MORNING HOURS IN ADVANCE OF APPROACHING LOW
PRESSURE.  SOUTHWEST FLOW ALOFT OVERRUNING THE COLD DOME AT THE
SURFACE MAY ALLOW FOR SOME LIGHT SNOW/FLURRIES TO BREAK
OUT ACROSS THE INTERIOR LATE THIS MORNING/EARLY AFTERNOON AND THEN
FIND THEIR WAY TO THE COAST BY MID TO LATE AFTERNOON.  THE LIFT
THROUGH MID AFTERNOON IS FAIRLY WEAK...SO THE AREAS OF SNOW SHOULD
BE RATHER LIGHT. ANY ACCUMULATIONS THAT OCCUR WILL PROBABLY BE
A DUSTING TO LESS THAN 1 INCH THROUGH THAT THAT TIME.  HIGH TEMPS
WILL MAINLY BE IN THE UPPER 20S TO AROUND 30.

&&

.SHORT TERM /3 PM THIS AFTERNOON THROUGH 6 AM MONDAY/...
*** BULK OF THE ACCUMULATING SNOW OCCURS BETWEEN 3 PM AND 1 AM WITH
  THE HEAVIEST AMOUNTS SOUTH OF THE MA TURNPIKE ***

1) OVERVIEW AND TIMING:

THE BULK OF THE ACCUMULATING SNOW WILL OCCUR BETWEEN 3 PM AND
1 AM ACROSS THE REGION.  THE SNOW SHOULD TAPER OFF TO FLURRIES
TOWARD DAYBREAK MONDAY.  THE MODELS DO AGREE THAT THE BETTER FORCING
WILL OCCUR TO THE SOUTH OF THE MA TURNPIKE.  THIS A RESULT
OF SECONDARY LOW PRESSURE NEAR THE SOUTH COAST...ALLOWING FOR
SOME SURFACE CONVERGENCE AS WELL AS THE INTENSIFICATION OF THE LOW
LEVEL JET.

THE BIGGEST ISSUE IS THE MODELS ARE NOT IN AGREEMENT IN HOW
INTENSE THE FORCING WILL BE ACROSS THE REGION THIS EVENING.  THE
RGEM/NAM ARE THE MOST ROBUST WITH QPF SOUTH OF THE MA TURNPIKE.  THE
NAM SHOWS A PERIOD OF FAIRLY STRONG LIFT OF 15 TO 20 MICROBARS PER
SECOND WITHIN THE BEST SNOWGROWTH REGION THIS EVENING.  THIS WOULD
TRANSLATE TO A PERIOD OF 1+ INCH PER HOUR SNOWFALL RATES NEAR AND
SOUTH OF THE MA PIKE.  ON THE OTHER HAND...THE GFS ALSO HAS FAIRLY
STRONG LIFT...BUT KEEPS IT SOUTHEAST OF OUR REGION OUT OVER THE
OCEAN.  THE SECONDARY LOW PRESSURE SYSTEM ON THE GFS IS WEAKER AND
FURTHER SOUTHEAST...RESULTING IN THE LOW LEVEL JET BEING DISPLACED
FURTHER EAST.  THE ECMWF/UKMET SOLUTIONS SEEM TO BE THE MIDDLE
GROUND WHICH WE WILL LEAN TOWARDS.

2) WINTER WEATHER HEADLINES AND SNOW ACCUMS:

WITH THAT SAID...THE OTHER DILEMMA IS WHAT TO DO WITH THE CURRENT
HEADLINES.  THIS DOES NOT APPEAR TO BE THE TYPE OF SETUP WHERE WE
ARE GOING TO RECEIVE WIDESPREAD WARNING SNOWFALL AMOUNTS.  THE
WINDOW FOR THE VERY STRONG LIFT/FORCING IS SHORT-LIVED AND REALLY
WOULD LIKE TO SEE THE LOW LEVEL JET A BIT MORE BACKED TO TRANSPORT
DEEPER MOISTURE NORTHWARD.  THEREFORE...FEEL THAT FOR MOST OF THE
REGION WINTER WEATHER ADVISORY/S FOR 3 TO 6 INCHES OF SNOW WILL
COVER IT.  HOWEVER...GIVEN THERE IS NICE OMEGA IN THE SNOW GROWTH
REGION...WE MIGHT BE LOOKING AT SOME DECENT RATIOS.  SO WE STILL CAN
NOT RULE OUT THE LOW RISK OF REACHING WARNING AMOUNTS AND LATER
SHIFTS WILL HAVE TO MONITOR CLOSELY...ESPECIALLY ACROSS NORTHERN CT
AND NORTHWEST RI.

WE DID UPGRADE A SMALL AREA FROM CENTRAL AND SOUTHERN RHODE ISLAND
INTO SOUTHEAST MA INCLUDING THE SOUTH COAST TO A WINTER
STORM WARNING.  THE NOSE OF THE LOW LEVEL JET LOOKS TO TRANSPORT
SOME DEEPER MOISTURE INTO THIS REGION.  THERE ALSO COULD BE SOME
ENHANCEMENT ALONG THE LAND/SEA INTERFACE AND A WEAK SURFACE
BOUNDARY SO WENT WITH 4 TO 8 INCHES IN THIS REGION.

3) PTYPE AND IMPACTS:

THE MODELS HAVE TRENDED COLDER OVER THE PAST 24 HOURS.
THEREFORE...EXPECT THIS BE PRETTY MUCH A SNOW EVENT.  IT DOES BECOME
A VERY CLOSE CALL NEAR THE SOUTH COAST...BUT WERE LEANING TOWARDS IT
STAYING MAINLY WET SNOW.  IF PRECIPITATION LIGHTENS UP THAT MAY
INCREASE THIS RISK WE SEE A BRIEF CHANGE OVER TO RAIN.
MEANWHILE...WE WENT WITH A HIGH END WINTER WEATHER ADVISORY FOR THE
CAPE BECAUSE THEY MAY CHANGE TO RAIN FOR A TIME...ESPECIALLY EAST OF
HYANNIS.  IF THE CHANGE OVER DOES NOT OCCUR...WE MAY NEED TO UPGRADE
THEM TO A WINTER STORM WARNING ESPECIALLY NEAR THE CAPE COD CANAL
GIVEN EXPECTED QPF.

THE ONE THING WILL ALSO HAVE TO WATCH IS AREAS NEAR THE SOUTH COAST
AND CAPE COD.  LOOKS TO BE A WET SNOW DOWN THAT WAY AND ON GOING
ROOF ISSUES MAY BE EXACERBATED...ESPECIALLY IF ANY AREAS THAT ARE
ABLE TO EXCEED 6 INCHES OF WET SNOW.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
HIGHLIGHTS...

  * BLUSTERY CONDITIONS ON MON WITH DRY WEATHER CONTINUING INTO
    TUE.
  * A STORM SYSTEM BRINGS MIXED PRECIP TUE INTO WED.
  * CONDITIONS IMPROVE THU BUT BECOMING COLD AGAIN.

OVERVIEW AND MODEL PREFERENCES...
A SPLIT FLOW MERGER WILL BE THE DEFINING FACTOR THROUGH THE LONG
TERM FORECAST PERIOD. IN THE MID TERM...THE STREAMS MERGE THANKS
TO PHASING OF NRN AND SRN STREAM SHORTWAVES UPSTREAM AS MERGING
STRONG JET DEVELOPS ACROSS THE NE CONUS. THESE FEATURES WILL ALLOW
LOW PRES TO GRADUALLY DEEPEN AND SLIDE THROUGH SRN ONTARIO AND
QUEBEC...CREATING AN OVERRUNNING EVENT AS THE SYSTEM ATTEMPTS TO
OCCLUDE. THIS IS THE MIXED PRECIP EVENT WE HAVE BEEN DISCUSSING
FOR SOME TIME NOW. NOW THAT NAM HAS CAPTURED IT...IT APPEARS
COLDER THAN MOST OF THE DETERMINISTIC GUIDANCE...WHILE THE ECMWF
STARTS COLD AND SHIFTS TO THE WARMER SIDE OF THE ENVELOPE DUE TO
THE FACT THAT IT IS MORE AMPLIFIED THAN OTHER MODELS. THE
GFS...ECENS/GEFS MEANS ARE ACTUALLY A GOOD MIDDLE GROUND HERE.
THIS BLEND WILL BE USED THROUGH THE REMAINDER OF THE LONG TERM AS
WELL TO TAKE INTO ACCOUNT THE VARIOUS SOLUTIONS.

DETAILS...

MON INTO TUE...
REMNANT SNOWFALLS WILL BE GRADUALLY COMING TO AN END THROUGH MID
MORNING MON...ALTHOUGH FLURRIES MAY LINGER A BIT LONGER IN THE
BERKSHIRES. STRONG HIGH PRES WILL THEN SLIDE ACROSS THE REGION
THROUGH TUE...WITH MAINLY DRY WX. TEMPS LOOK TO REMAIN BELOW
NORMAL GIVEN LITTLE CHANGE IN THE AIRMASS FROM PREVIOUS DAYS.

TUE NIGHT INTO WED...
OVERRUNNING EVENT EXPECTED AS WARM FRONT WILL ATTEMPT TO PUSH N
ACROSS THE REGION BUT IS LIKELY TO STRUGGLE NEAR THE SFC DUE TO
ENTRENCHED COLD AIR AND A DEEP SNOWPACK. HOWEVER...50-60 KT LLJ
WITH STRONG SLY COMPONENT WILL ALLOW UPPER LVL WARMING TON
CONTINUE UNIMPEDED. IN SPITE OF THE STRONG JET AT ONLY 3-5KFT
ABOVE THE SFC...SNOWPACK WILL MAKE MIXING DIFFICULT SO NOT
EXPECTING SIGNIFICANT WIND ISSUES AT THIS TIME.

THE COLUMN STARTS COLD ENOUGH FOR SNOW AT ONSET TUE EVENING...AND
LOOKS LIKE AS MUCH AS 0.40-0.60 OF THE TOTAL EVENT QPF FALLS AS
SNOW INITIALLY EVERYWHERE...WITH GRADUAL CHANGEOVER DURING THE
EARLY MORNING HOURS WED MORNING FROM S-N. THEREFORE...COULD SEE AT
LEAST ADVISORY IF NOT LOW-END WARNING LVL SNOWFALLS THROUGH THE
OVERNIGHT HOURS BEFORE A TRANSITION TO SLEET...THEN FREEZING RAIN.
FREEZING RAIN COULD LOCK IN FOR SOME TIME AND GIVEN THAT H93 TEMPS
/EVEN ON THE COLDEST GUIDANCE/ AN AVERAGE OF +4C DURING THE 08Z-
16Z TIMEFRAME...BUT SFC TEMPS MAY HOLD NEAR FREEZING FOR SOME TIME
GIVEN THE DEEP SNOWPACK ACROSS THE AREA. HOWEVER...STRAIGHT RAIN
FOR A TIME FROM ABOUT MID MORNING INTO THE AFTERNOON IS LIKELY
UNTIL THE PRECIP COMES TO AN END. DEPENDING ON HOW QUICKLY 2M
TEMPS REBOUND...AS MUCH AS A QUARTER INCH OF ICE CAN/T BE RULED
OUT. AGREE WITH PREVIOUS FORECASTER THAT LEANING A BIT COLDER THAN
MOS 2M TEMPS IS PROBABLY THE WAY TO GO.

MODEST UPPER LVL INSTABILITY AS WARMING OCCURS IN THE MID LVLS
COULD ALSO MEAN A PERIOD OF HEAVY PRECIP...BOTH SNOW AND RAIN.
WITH THE RAIN...COMES A RISK FOR POOR DRAINAGE FLOODING ACROSS THE
REGION AS SNOW MELTS AND DRAINS BECOME CLOGGED. PRECIP COMES TO AN
END ACROSS MOST OF THE REGION BY AFTERNOON WED...BUT MAY LINGER A
BIT NEAR THE S COAST...MORE ON THAT BELOW.

WED NIGHT INTO THU...
CONFIDENCE IN THE FORECAST CONTINUES TO DIMINISH HERE PARTIALLY
DEPENDENT ON HOW FAST THE UPPER LVL JET EXITS TO THE EAST AND HOW
AMPLIFIED THE PATTERN REMAINS IN THE WAKE OF THE LOW PRES. THE
MORE AMPLIFIED GUIDANCE...LED BY THE ECMWF KEEPS THE COLD FRONT
JUST OFFSHORE AND WITHIN THE EQUATORWARD ENTRANCE REGION OF THE
UPPER LVL JET. THIS SUGGESTS S COASTAL AREAS COULD CONTINUE TO SEE
PRECIP...POSSIBLY EVEN CHANGING BACK TO SNOW FOR A TIME WELL INTO
THE DAY ON THU. THE MORE PROGRESSIVE GUIDANCE...LED BY THE GFS
WOULD MOVE BOTH OF THESE FEATURES OFFSHORE SUCH THAT THU IS
MAINLY DRY AND BECOMING QUITE COLD AS ANOTHER ARCTIC AIRMASS
SETTLES IN. FOR NOW...WILL CONTINUE TO LEAN ON THE MORE
PROGRESSIVE GFS BUT WITH THE ECENS/GEFS SLOWER MEMBERS BLENDED IN.
THE FINAL ANSWER WILL LIKELY BE SOMEWHERE IN BETWEEN THE TWO
SOLUTIONS. IN ANY CASE...MUCH COLDER AIRMASS EXPECTED TO MOVE IN.

THU NIGHT INTO FRI NIGHT...
COLD AIRMASS ACROSS THE REGION ASSOCIATED WITH YET ANOTHER 1035+
HPA HIGH PRES. WILL LIKELY SEE HIGHS ONLY MAKING THE TEENS AND 20S
WITH LOWS BACK IN THE SINGLE DIGITS ABOVE AND BELOW ZERO.

NEXT WEEKEND...
SOME UNCERTAINTY HERE AS TO WHETHER YET ANOTHER WAVE WILL BE
EFFECT THE REGION. WILL LEAN MAINLY DRY FOR NOW AS THE AIRMASS IN
PLACE IS QUITE DRY AND THE WAVE ITSELF IS QUITE WEAK AND SHEARING
OUT.

&&

.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TODAY AND TONIGHT/...

TODAY AND TONIGHT...MODERATE CONFIDENCE.  VFR CONDITIONS THROUGH AT
LEAST MID MORNING.  SOME MVFR TO IFR CONDITIONS DEVELOP FROM WEST TO
EAST LATE THIS MORNING AND THIS AFTERNOON IN AREAS OF LIGHT SNOW.
HOWEVER...THE BULK OF THE MODERATE TO EVEN BRIEFLY HEAVY SNOW WILL
OCCUR THIS EVENING WHEN WIDESPREAD IFR TO LIFR CONDITIONS OCCUR.
THE LOWER CONDITIONS MOST LIKELY SOUTH OF THE MA TURNPIKE.  PTYPE
PRETTY MUCH ALL SNOW...EXCEPT FOR THE VERY IMMEDIATE SOUTH
COAST/CAPE WHERE SNOW MAY MIX WITH OR CHANGE TO RAIN FOR A TIME.
WHETHER OR NOT THAT HAPPENS IS UNCERTAIN...BUT WE DO THINK THAT AT
LEAST THE ISLANDS WILL CHANGE TO RAIN.

BULK OF SNOW ENDS BY 8 OR 9Z TONIGHT AND MUCH OF THE THE REGION
SHOULD ALREADY HAVE VFR CONDITIONS BY 12Z MONDAY.

KBOS TAF...CONFIDENT IN OVERALL TRENDS BUT EXACT TIMING IS MORE
UNCERTAIN.  WHILE SOME LIGHT SNOW IS POSSIBLE THIS
AFTERNOON...BULK OF ACCUMULATING SNOW WITH WIDESPREAD IFR TO LIFR
CONDITIONS EXPECTED THIS EVENING.

KBDL TAF...CONFIDENT IN OVERALL TRENDS BUT EXACT TIMING IS MORE
UNCERTAIN.  WHILE SOME LIGHT SNOW IS POSSIBLE LATE THIS MORNING AND
AFTERNOON...BULK OF ACCUMULATING SNOW WITH WIDESPREAD IFR TO LIFR
CONDITIONS EXPECTED AFTER 3 OR 4 PM.

OUTLOOK...MONDAY THROUGH THURSDAY...

MONDAY...HIGH CONFIDENCE.
IFR/MVFR IN REMNANT SNOWS END EARLY...WITH TRANSITION TO VFR
EVERYWHERE BY AFTERNOON. W-NW WIND GUSTS UP TO AROUND 30 KT AT
TIMES DURING THE AFTERNOON AND EVENING.

MON NIGHT INTO TUE...HIGH CONFIDENCE.
MAINLY VFR. WINDS DIMINISH MON NIGHT.

TUE NIGHT INTO THU...MODERATE CONFIDENCE.
A MESSY PERIOD. SNOW BEGINS EVERYWHERE LATE TUE INTO WED NIGHT
WITH MODERATE ACCUMS POSSIBLE...THEN EXPECT GRADUALLY TRANSITION
TO SLEET AND FREEZING RAIN DURING THE EARLY MORNING HOURS
WED...THEN TO ALL RAIN DURING THE DAY ON WED. SOME ICE ACCUM
POSSIBLE AS WELL. THE RAIN DIMINISHES LATE WED BUT MAY LINGER
ALONG THE S COAST AND EVEN CHANGE TO SNOW INTO THE DAY ON THU.
EXPECT PERIODS OF IFR/LIFR CONDITIONS THROUGHOUT THE PERIOD WITH
SOME IMPROVEMENT FROM N-S ON THU. LLWS LIKELY ESPECIALLY TUE NIGHT
AND EARLY WED.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TODAY AND TONIGHT/...HIGH CONFIDENCE.

A WEAK WAVE OF LOW PRESSURE MOVES ACROSS THE WATERS LATER
TODAY AND TONIGHT.  WEAK PRESSURE GRADIENT SHOULD KEEP
WINDS/SEAS BELOW SMALL CRAFT THRESHOLDS TODAY AND TONIGHT.  THE
SYSTEM REALLY INTENSIFIES AS IT MOVES INTO THE CANADIAN MARITIMES
NEAR DAYBREAK MONDAY...SO WESTERLY WIND GUSTS MAY REACH 20 TO 25
KNOTS NEAR 12Z MONDAY.  OTHERWISE...RAIN AND SNOW LATE TODAY AND
ESPECIALLY TONIGHT WILL REDUCE VISIBILITIES AT TIMES FOR MARINERS.

OUTLOOK...MONDAY THROUGH THURSDAY..MODERATE CONFIDENCE.

MONDAY INTO MONDAY NIGHT...HIGH CONFIDENCE.
WINDS BEGIN OUT OF THE SW THEN SHIFT TO W-NW IN THE AFTERNOON.
WIND GUSTS REACH 35-40 KT DURING THE AFTERNOON AND OVERNIGHT SO
WILL BE ISSUING A GALE WATCH. SEAS BUILD 10-12 FT ON THE OCEAN
WATERS. SOME LIGHT FREEZING SPRAY POSSIBLE MON EVENING INTO TUE
MORNING.

TUE...HIGH CONFIDENCE.
WINDS AND SEAS START AT OR AROUND SMALL CRAFT ADVISORY THRESHOLDS
BUT THEN DROP DURING THE DAY SUCH THAT A PERIOD OF QUIET BOATING
WEATHER IS LIKELY TUE AFTERNOON AND EVENING.

TUE NIGHT INTO THU...MODERATE CONFIDENCE.
LOW PRES PASSES WELL INLAND...WITH WINDS OUT OF THE S GRADUALLY
SHIFTING TO THE W LATE WED INTO THU. PERIODS OF WIND GUSTS 25-30
KT EXPECTED ALTHOUGH GUSTS MAY APPROACH GALE FORCE WED EVENING.
SEAS BUILD THROUGH WED TO AROUND 7-10FT ON THE OCEAN WATERS THEN
DIMINISH THU. AT THE VERY LEAST SMALL CRAFT ADVISORIES ARE LIKELY
DURING THIS PERIOD. PERIODS OF SNOW CHANGING TO RAIN EARLY WED
WITH SOME LOW VSBYS IN RAIN AND FOG ON WED.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WINTER WEATHER ADVISORY FROM NOON TODAY TO 7 AM EST MONDAY FOR
     CTZ002>004.
MA...WINTER WEATHER ADVISORY FROM NOON TODAY TO 7 AM EST MONDAY FOR
     MAZ002>016-022>024-026.
     WINTER STORM WARNING FROM 3 PM THIS AFTERNOON TO 7 AM EST
     MONDAY FOR MAZ017>021.
RI...WINTER WEATHER ADVISORY FROM NOON TODAY TO 7 AM EST MONDAY FOR
     RIZ001-008.
     WINTER STORM WARNING FROM 3 PM THIS AFTERNOON TO 7 AM EST
     MONDAY FOR RIZ002>007.
MARINE...GALE WATCH FROM MONDAY MORNING THROUGH LATE MONDAY NIGHT FOR
     ANZ231>235-237-250-251-254>256.

&&

$$
SYNOPSIS...FRANK/DOODY
NEAR TERM...FRANK
SHORT TERM...FRANK
LONG TERM...DOODY
AVIATION...FRANK/DOODY
MARINE...FRANK/DOODY




000
FXUS61 KBOX 010958
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
458 AM EST SUN MAR 1 2015

.SYNOPSIS...
A FAST MOVING LOW PRESSURE SYSTEM WILL BRING ACCUMULATING SNOW
LATER TODAY AND ESPECIALLY TONIGHT WITH THE HIGHEST AMOUNTS
EXPECTED SOUTH OF THE MASSACHUSETTS TURNPIKE.HIGH PRESSURE BRINGS
DRY COLD AIR FOR THE EARLY WEEK. LOW PRESSURE FROM NORTHERN CANADA
AND ASSOCIATED LOW FORMING OVER THE PLAINS MONDAY WILL
MERGE...THEN PASS WEST AND NORTH OF NEW ENGLAND. THIS WILL SWING A
COLD FRONT ACROSS THE REGION ON WEDNESDAY. DRY AND COLD WEATHER
RETURNS FOR THE END OF THE WEEK.

&&

.NEAR TERM /UNTIL 3 PM THIS AFTERNOON/...

MID LEVEL CLOUDINESS WILL STREAM INTO SOUTHERN NEW ENGLAND AND
THICKEN DURING THE MORNING HOURS IN ADVANCE OF APPROACHING LOW
PRESSURE.  SOUTHWEST FLOW ALOFT OVERRUNING THE COLD DOME AT THE
SURFACE MAY ALLOW FOR SOME LIGHT SNOW/FLURRIES TO BREAK
OUT ACROSS THE INTERIOR LATE THIS MORNING/EARLY AFTERNOON AND THEN
FIND THEIR WAY TO THE COAST BY MID TO LATE AFTERNOON.  THE LIFT
THROUGH MID AFTERNOON IS FAIRLY WEAK...SO THE AREAS OF SNOW SHOULD
BE RATHER LIGHT. ANY ACCUMULATIONS THAT OCCUR WILL PROBABLY BE
A DUSTING TO LESS THAN 1 INCH THROUGH THAT THAT TIME.  HIGH TEMPS
WILL MAINLY BE IN THE UPPER 20S TO AROUND 30.

&&

.SHORT TERM /3 PM THIS AFTERNOON THROUGH 6 AM MONDAY/...
*** BULK OF THE ACCUMULATING SNOW OCCURS BETWEEN 3 PM AND 1 AM WITH
  THE HEAVIEST AMOUNTS SOUTH OF THE MA TURNPIKE ***

1) OVERVIEW AND TIMING:

THE BULK OF THE ACCUMULATING SNOW WILL OCCUR BETWEEN 3 PM AND
1 AM ACROSS THE REGION.  THE SNOW SHOULD TAPER OFF TO FLURRIES
TOWARD DAYBREAK MONDAY.  THE MODELS DO AGREE THAT THE BETTER FORCING
WILL OCCUR TO THE SOUTH OF THE MA TURNPIKE.  THIS A RESULT
OF SECONDARY LOW PRESSURE NEAR THE SOUTH COAST...ALLOWING FOR
SOME SURFACE CONVERGENCE AS WELL AS THE INTENSIFICATION OF THE LOW
LEVEL JET.

THE BIGGEST ISSUE IS THE MODELS ARE NOT IN AGREEMENT IN HOW
INTENSE THE FORCING WILL BE ACROSS THE REGION THIS EVENING.  THE
RGEM/NAM ARE THE MOST ROBUST WITH QPF SOUTH OF THE MA TURNPIKE.  THE
NAM SHOWS A PERIOD OF FAIRLY STRONG LIFT OF 15 TO 20 MICROBARS PER
SECOND WITHIN THE BEST SNOWGROWTH REGION THIS EVENING.  THIS WOULD
TRANSLATE TO A PERIOD OF 1+ INCH PER HOUR SNOWFALL RATES NEAR AND
SOUTH OF THE MA PIKE.  ON THE OTHER HAND...THE GFS ALSO HAS FAIRLY
STRONG LIFT...BUT KEEPS IT SOUTHEAST OF OUR REGION OUT OVER THE
OCEAN.  THE SECONDARY LOW PRESSURE SYSTEM ON THE GFS IS WEAKER AND
FURTHER SOUTHEAST...RESULTING IN THE LOW LEVEL JET BEING DISPLACED
FURTHER EAST.  THE ECMWF/UKMET SOLUTIONS SEEM TO BE THE MIDDLE
GROUND WHICH WE WILL LEAN TOWARDS.

2) WINTER WEATHER HEADLINES AND SNOW ACCUMS:

WITH THAT SAID...THE OTHER DILEMMA IS WHAT TO DO WITH THE CURRENT
HEADLINES.  THIS DOES NOT APPEAR TO BE THE TYPE OF SETUP WHERE WE
ARE GOING TO RECEIVE WIDESPREAD WARNING SNOWFALL AMOUNTS.  THE
WINDOW FOR THE VERY STRONG LIFT/FORCING IS SHORT-LIVED AND REALLY
WOULD LIKE TO SEE THE LOW LEVEL JET A BIT MORE BACKED TO TRANSPORT
DEEPER MOISTURE NORTHWARD.  THEREFORE...FEEL THAT FOR MOST OF THE
REGION WINTER WEATHER ADVISORY/S FOR 3 TO 6 INCHES OF SNOW WILL
COVER IT.  HOWEVER...GIVEN THERE IS NICE OMEGA IN THE SNOW GROWTH
REGION...WE MIGHT BE LOOKING AT SOME DECENT RATIOS.  SO WE STILL CAN
NOT RULE OUT THE LOW RISK OF REACHING WARNING AMOUNTS AND LATER
SHIFTS WILL HAVE TO MONITOR CLOSELY...ESPECIALLY ACROSS NORTHERN CT
AND NORTHWEST RI.

WE DID UPGRADE A SMALL AREA FROM CENTRAL AND SOUTHERN RHODE ISLAND
INTO SOUTHEAST MA INCLUDING THE SOUTH COAST TO A WINTER
STORM WARNING.  THE NOSE OF THE LOW LEVEL JET LOOKS TO TRANSPORT
SOME DEEPER MOISTURE INTO THIS REGION.  THERE ALSO COULD BE SOME
ENHANCEMENT ALONG THE LAND/SEA INTERFACE AND A WEAK SURFACE
BOUNDARY SO WENT WITH 4 TO 8 INCHES IN THIS REGION.

3) PTYPE AND IMPACTS:

THE MODELS HAVE TRENDED COLDER OVER THE PAST 24 HOURS.
THEREFORE...EXPECT THIS BE PRETTY MUCH A SNOW EVENT.  IT DOES BECOME
A VERY CLOSE CALL NEAR THE SOUTH COAST...BUT WERE LEANING TOWARDS IT
STAYING MAINLY WET SNOW.  IF PRECIPITATION LIGHTENS UP THAT MAY
INCREASE THIS RISK WE SEE A BRIEF CHANGE OVER TO RAIN.
MEANWHILE...WE WENT WITH A HIGH END WINTER WEATHER ADVISORY FOR THE
CAPE BECAUSE THEY MAY CHANGE TO RAIN FOR A TIME...ESPECIALLY EAST OF
HYANNIS.  IF THE CHANGE OVER DOES NOT OCCUR...WE MAY NEED TO UPGRADE
THEM TO A WINTER STORM WARNING ESPECIALLY NEAR THE CAPE COD CANAL
GIVEN EXPECTED QPF.

THE ONE THING WILL ALSO HAVE TO WATCH IS AREAS NEAR THE SOUTH COAST
AND CAPE COD.  LOOKS TO BE A WET SNOW DOWN THAT WAY AND ON GOING
ROOF ISSUES MAY BE EXACERBATED...ESPECIALLY IF ANY AREAS THAT ARE
ABLE TO EXCEED 6 INCHES OF WET SNOW.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
HIGHLIGHTS...

  * BLUSTERY CONDITIONS ON MON WITH DRY WEATHER CONTINUING INTO
    TUE.
  * A STORM SYSTEM BRINGS MIXED PRECIP TUE INTO WED.
  * CONDITIONS IMPROVE THU BUT BECOMING COLD AGAIN.

OVERVIEW AND MODEL PREFERENCES...
A SPLIT FLOW MERGER WILL BE THE DEFINING FACTOR THROUGH THE LONG
TERM FORECAST PERIOD. IN THE MID TERM...THE STREAMS MERGE THANKS
TO PHASING OF NRN AND SRN STREAM SHORTWAVES UPSTREAM AS MERGING
STRONG JET DEVELOPS ACROSS THE NE CONUS. THESE FEATURES WILL ALLOW
LOW PRES TO GRADUALLY DEEPEN AND SLIDE THROUGH SRN ONTARIO AND
QUEBEC...CREATING AN OVERRUNNING EVENT AS THE SYSTEM ATTEMPTS TO
OCCLUDE. THIS IS THE MIXED PRECIP EVENT WE HAVE BEEN DISCUSSING
FOR SOME TIME NOW. NOW THAT NAM HAS CAPTURED IT...IT APPEARS
COLDER THAN MOST OF THE DETERMINISTIC GUIDANCE...WHILE THE ECMWF
STARTS COLD AND SHIFTS TO THE WARMER SIDE OF THE ENVELOPE DUE TO
THE FACT THAT IT IS MORE AMPLIFIED THAN OTHER MODELS. THE
GFS...ECENS/GEFS MEANS ARE ACTUALLY A GOOD MIDDLE GROUND HERE.
THIS BLEND WILL BE USED THROUGH THE REMAINDER OF THE LONG TERM AS
WELL TO TAKE INTO ACCOUNT THE VARIOUS SOLUTIONS.

DETAILS...

MON INTO TUE...
REMNANT SNOWFALLS WILL BE GRADUALLY COMING TO AN END THROUGH MID
MORNING MON...ALTHOUGH FLURRIES MAY LINGER A BIT LONGER IN THE
BERKSHIRES. STRONG HIGH PRES WILL THEN SLIDE ACROSS THE REGION
THROUGH TUE...WITH MAINLY DRY WX. TEMPS LOOK TO REMAIN BELOW
NORMAL GIVEN LITTLE CHANGE IN THE AIRMASS FROM PREVIOUS DAYS.

TUE NIGHT INTO WED...
OVERRUNNING EVENT EXPECTED AS WARM FRONT WILL ATTEMPT TO PUSH N
ACROSS THE REGION BUT IS LIKELY TO STRUGGLE NEAR THE SFC DUE TO
ENTRENCHED COLD AIR AND A DEEP SNOWPACK. HOWEVER...50-60 KT LLJ
WITH STRONG SLY COMPONENT WILL ALLOW UPPER LVL WARMING TON
CONTINUE UNIMPEDED. IN SPITE OF THE STRONG JET AT ONLY 3-5KFT
ABOVE THE SFC...SNOWPACK WILL MAKE MIXING DIFFICULT SO NOT
EXPECTING SIGNIFICANT WIND ISSUES AT THIS TIME.

THE COLUMN STARTS COLD ENOUGH FOR SNOW AT ONSET TUE EVENING...AND
LOOKS LIKE AS MUCH AS 0.40-0.60 OF THE TOTAL EVENT QPF FALLS AS
SNOW INITIALLY EVERYWHERE...WITH GRADUAL CHANGEOVER DURING THE
EARLY MORNING HOURS WED MORNING FROM S-N. THEREFORE...COULD SEE AT
LEAST ADVISORY IF NOT LOW-END WARNING LVL SNOWFALLS THROUGH THE
OVERNIGHT HOURS BEFORE A TRANSITION TO SLEET...THEN FREEZING RAIN.
FREEZING RAIN COULD LOCK IN FOR SOME TIME AND GIVEN THAT H93 TEMPS
/EVEN ON THE COLDEST GUIDANCE/ AN AVERAGE OF +4C DURING THE 08Z-
16Z TIMEFRAME...BUT SFC TEMPS MAY HOLD NEAR FREEZING FOR SOME TIME
GIVEN THE DEEP SNOWPACK ACROSS THE AREA. HOWEVER...STRAIGHT RAIN
FOR A TIME FROM ABOUT MID MORNING INTO THE AFTERNOON IS LIKELY
UNTIL THE PRECIP COMES TO AN END. DEPENDING ON HOW QUICKLY 2M
TEMPS REBOUND...AS MUCH AS A QUARTER INCH OF ICE CAN/T BE RULED
OUT. AGREE WITH PREVIOUS FORECASTER THAT LEANING A BIT COLDER THAN
MOS 2M TEMPS IS PROBABLY THE WAY TO GO.

MODEST UPPER LVL INSTABILITY AS WARMING OCCURS IN THE MID LVLS
COULD ALSO MEAN A PERIOD OF HEAVY PRECIP...BOTH SNOW AND RAIN.
WITH THE RAIN...COMES A RISK FOR POOR DRAINAGE FLOODING ACROSS THE
REGION AS SNOW MELTS AND DRAINS BECOME CLOGGED. PRECIP COMES TO AN
END ACROSS MOST OF THE REGION BY AFTERNOON WED...BUT MAY LINGER A
BIT NEAR THE S COAST...MORE ON THAT BELOW.

WED NIGHT INTO THU...
CONFIDENCE IN THE FORECAST CONTINUES TO DIMINISH HERE PARTIALLY
DEPENDENT ON HOW FAST THE UPPER LVL JET EXITS TO THE EAST AND HOW
AMPLIFIED THE PATTERN REMAINS IN THE WAKE OF THE LOW PRES. THE
MORE AMPLIFIED GUIDANCE...LED BY THE ECMWF KEEPS THE COLD FRONT
JUST OFFSHORE AND WITHIN THE EQUATORWARD ENTRANCE REGION OF THE
UPPER LVL JET. THIS SUGGESTS S COASTAL AREAS COULD CONTINUE TO SEE
PRECIP...POSSIBLY EVEN CHANGING BACK TO SNOW FOR A TIME WELL INTO
THE DAY ON THU. THE MORE PROGRESSIVE GUIDANCE...LED BY THE GFS
WOULD MOVE BOTH OF THESE FEATURES OFFSHORE SUCH THAT THU IS
MAINLY DRY AND BECOMING QUITE COLD AS ANOTHER ARCTIC AIRMASS
SETTLES IN. FOR NOW...WILL CONTINUE TO LEAN ON THE MORE
PROGRESSIVE GFS BUT WITH THE ECENS/GEFS SLOWER MEMBERS BLENDED IN.
THE FINAL ANSWER WILL LIKELY BE SOMEWHERE IN BETWEEN THE TWO
SOLUTIONS. IN ANY CASE...MUCH COLDER AIRMASS EXPECTED TO MOVE IN.

THU NIGHT INTO FRI NIGHT...
COLD AIRMASS ACROSS THE REGION ASSOCIATED WITH YET ANOTHER 1035+
HPA HIGH PRES. WILL LIKELY SEE HIGHS ONLY MAKING THE TEENS AND 20S
WITH LOWS BACK IN THE SINGLE DIGITS ABOVE AND BELOW ZERO.

NEXT WEEKEND...
SOME UNCERTAINTY HERE AS TO WHETHER YET ANOTHER WAVE WILL BE
EFFECT THE REGION. WILL LEAN MAINLY DRY FOR NOW AS THE AIRMASS IN
PLACE IS QUITE DRY AND THE WAVE ITSELF IS QUITE WEAK AND SHEARING
OUT.

&&

.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TODAY AND TONIGHT/...

TODAY AND TONIGHT...MODERATE CONFIDENCE.  VFR CONDITIONS THROUGH AT
LEAST MID MORNING.  SOME MVFR TO IFR CONDITIONS DEVELOP FROM WEST TO
EAST LATE THIS MORNING AND THIS AFTERNOON IN AREAS OF LIGHT SNOW.
HOWEVER...THE BULK OF THE MODERATE TO EVEN BRIEFLY HEAVY SNOW WILL
OCCUR THIS EVENING WHEN WIDESPREAD IFR TO LIFR CONDITIONS OCCUR.
THE LOWER CONDITIONS MOST LIKELY SOUTH OF THE MA TURNPIKE.  PTYPE
PRETTY MUCH ALL SNOW...EXCEPT FOR THE VERY IMMEDIATE SOUTH
COAST/CAPE WHERE SNOW MAY MIX WITH OR CHANGE TO RAIN FOR A TIME.
WHETHER OR NOT THAT HAPPENS IS UNCERTAIN...BUT WE DO THINK THAT AT
LEAST THE ISLANDS WILL CHANGE TO RAIN.

BULK OF SNOW ENDS BY 8 OR 9Z TONIGHT AND MUCH OF THE THE REGION
SHOULD ALREADY HAVE VFR CONDITIONS BY 12Z MONDAY.

KBOS TAF...CONFIDENT IN OVERALL TRENDS BUT EXACT TIMING IS MORE
UNCERTAIN.  WHILE SOME LIGHT SNOW IS POSSIBLE THIS
AFTERNOON...BULK OF ACCUMULATING SNOW WITH WIDESPREAD IFR TO LIFR
CONDITIONS EXPECTED THIS EVENING.

KBDL TAF...CONFIDENT IN OVERALL TRENDS BUT EXACT TIMING IS MORE
UNCERTAIN.  WHILE SOME LIGHT SNOW IS POSSIBLE LATE THIS MORNING AND
AFTERNOON...BULK OF ACCUMULATING SNOW WITH WIDESPREAD IFR TO LIFR
CONDITIONS EXPECTED AFTER 3 OR 4 PM.

OUTLOOK...MONDAY THROUGH THURSDAY...

MONDAY...HIGH CONFIDENCE.
IFR/MVFR IN REMNANT SNOWS END EARLY...WITH TRANSITION TO VFR
EVERYWHERE BY AFTERNOON. W-NW WIND GUSTS UP TO AROUND 30 KT AT
TIMES DURING THE AFTERNOON AND EVENING.

MON NIGHT INTO TUE...HIGH CONFIDENCE.
MAINLY VFR. WINDS DIMINISH MON NIGHT.

TUE NIGHT INTO THU...MODERATE CONFIDENCE.
A MESSY PERIOD. SNOW BEGINS EVERYWHERE LATE TUE INTO WED NIGHT
WITH MODERATE ACCUMS POSSIBLE...THEN EXPECT GRADUALLY TRANSITION
TO SLEET AND FREEZING RAIN DURING THE EARLY MORNING HOURS
WED...THEN TO ALL RAIN DURING THE DAY ON WED. SOME ICE ACCUM
POSSIBLE AS WELL. THE RAIN DIMINISHES LATE WED BUT MAY LINGER
ALONG THE S COAST AND EVEN CHANGE TO SNOW INTO THE DAY ON THU.
EXPECT PERIODS OF IFR/LIFR CONDITIONS THROUGHOUT THE PERIOD WITH
SOME IMPROVEMENT FROM N-S ON THU. LLWS LIKELY ESPECIALLY TUE NIGHT
AND EARLY WED.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TODAY AND TONIGHT/...HIGH CONFIDENCE.

A WEAK WAVE OF LOW PRESSURE MOVES ACROSS THE WATERS LATER
TODAY AND TONIGHT.  WEAK PRESSURE GRADIENT SHOULD KEEP
WINDS/SEAS BELOW SMALL CRAFT THRESHOLDS TODAY AND TONIGHT.  THE
SYSTEM REALLY INTENSIFIES AS IT MOVES INTO THE CANADIAN MARITIMES
NEAR DAYBREAK MONDAY...SO WESTERLY WIND GUSTS MAY REACH 20 TO 25
KNOTS NEAR 12Z MONDAY.  OTHERWISE...RAIN AND SNOW LATE TODAY AND
ESPECIALLY TONIGHT WILL REDUCE VISIBILITIES AT TIMES FOR MARINERS.

OUTLOOK...MONDAY THROUGH THURSDAY..MODERATE CONFIDENCE.

MONDAY INTO MONDAY NIGHT...HIGH CONFIDENCE.
WINDS BEGIN OUT OF THE SW THEN SHIFT TO W-NW IN THE AFTERNOON.
WIND GUSTS REACH 35-40 KT DURING THE AFTERNOON AND OVERNIGHT SO
WILL BE ISSUING A GALE WATCH. SEAS BUILD 10-12 FT ON THE OCEAN
WATERS. SOME LIGHT FREEZING SPRAY POSSIBLE MON EVENING INTO TUE
MORNING.

TUE...HIGH CONFIDENCE.
WINDS AND SEAS START AT OR AROUND SMALL CRAFT ADVISORY THRESHOLDS
BUT THEN DROP DURING THE DAY SUCH THAT A PERIOD OF QUIET BOATING
WEATHER IS LIKELY TUE AFTERNOON AND EVENING.

TUE NIGHT INTO THU...MODERATE CONFIDENCE.
LOW PRES PASSES WELL INLAND...WITH WINDS OUT OF THE S GRADUALLY
SHIFTING TO THE W LATE WED INTO THU. PERIODS OF WIND GUSTS 25-30
KT EXPECTED ALTHOUGH GUSTS MAY APPROACH GALE FORCE WED EVENING.
SEAS BUILD THROUGH WED TO AROUND 7-10FT ON THE OCEAN WATERS THEN
DIMINISH THU. AT THE VERY LEAST SMALL CRAFT ADVISORIES ARE LIKELY
DURING THIS PERIOD. PERIODS OF SNOW CHANGING TO RAIN EARLY WED
WITH SOME LOW VSBYS IN RAIN AND FOG ON WED.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WINTER WEATHER ADVISORY FROM NOON TODAY TO 7 AM EST MONDAY FOR
     CTZ002>004.
MA...WINTER WEATHER ADVISORY FROM NOON TODAY TO 7 AM EST MONDAY FOR
     MAZ002>016-022>024-026.
     WINTER STORM WARNING FROM 3 PM THIS AFTERNOON TO 7 AM EST
     MONDAY FOR MAZ017>021.
RI...WINTER WEATHER ADVISORY FROM NOON TODAY TO 7 AM EST MONDAY FOR
     RIZ001-008.
     WINTER STORM WARNING FROM 3 PM THIS AFTERNOON TO 7 AM EST
     MONDAY FOR RIZ002>007.
MARINE...GALE WATCH FROM MONDAY MORNING THROUGH LATE MONDAY NIGHT FOR
     ANZ231>235-237-250-251-254>256.

&&

$$
SYNOPSIS...FRANK/DOODY
NEAR TERM...FRANK
SHORT TERM...FRANK
LONG TERM...DOODY
AVIATION...FRANK/DOODY
MARINE...FRANK/DOODY




000
FXUS61 KGYX 010820
AFDGYX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
320 AM EST SUN MAR 1 2015

.SYNOPSIS...
LOW PRESSURE WILL MOVE IN FROM THE WEST TODAY AND WILL CROSS THE
REGION OVERNIGHT...PRODUCING SOME LIGHT SNOW. A STRONG NORTHWEST
FLOW WILL SET UP IN ITS WAKE ON MONDAY. HIGH PRESSURE WILL BUILD
IN FROM THE WEST MONDAY NIGHT AND WILL CREST OVER THE REGION EARLY
TUESDAY BEFORE MOVING OFFSHORE. LOW PRESSURE WILL SWING THROUGH
SOUTHERN CANADA TUESDAY NIGHT PUSHING A WARM NORTH ACROSS THE
REGION...AND PRODUCING A PERIOD OF SNOW...SLEET...OR FREEZING
RAIN. AS THE LOW SHIFT TO OUT NORTH...IT WILL DRAG A COLD FRONT
THROUGH THE REGION ON WEDNESDAY. HIGH PRESSURE WILL BUILD IN FROM
THE WEST THURSDAY AND WILL CREST OVER THE REGION ON FRIDAY.

&&

.NEAR TERM /THROUGH TODAY/...
CLOUDS WILL INCREASE AND THICKEN ACROSS THE REGION THIS MORNING
THROUGH MID AFTERNOON AS WEAK LOW PRESSURE PUSHES IN FROM THE
WEST. WILL SEE LIGHT SNOW BREAKING OUT IN NEW HAMPSHIRE DURING THE
MID TO LATE AFTERNOON AND THIS WILL PUSH EAST INTO WESTERN MAINE
THROUGH EARLY EVENING. ONLY LOOKING AT ACCUMULATIONS OF AN INCH OR
LESS THROUGH THE END OF THE DAY WITH MOST OF THAT IN SOUTHERN NEW
HAMPSHIRE. ONCE AGAIN TEMPERATURES WILL REMAIN BELOW NORMAL WITH
HIGH GENERALLY RANGING THROUGH THE 20S.

&&

.SHORT TERM /TONIGHT THROUGH 6 PM MONDAY/...
LIGHT SNOW WILL CONTINUE OVERNIGHT THROUGHOUT THE FORECAST AREA AS
LOW PRESSURE PUSHES THROUGH THE REGION. STORM TOTALS FOR MUCH OF
THE FORECAST AREA WILL BE IN THE 1 TO 3 INCH RANGE ALTHOUGH
SOUTHERN NEW HAMPSHIRE MAY SEE LOCALLY HIGHER AMOUNTS OF 2 TO 4
INCHES. LOWS TEMPS WILL BOTTOM OUT IN THE TEENS NORTH AND 20S
SOUTH.

TRAILING COLD FRONT WILL CROSS THE REGION MONDAY MORNING AS LOW
PRESSURE SHIFTS INTO THE MARITIMES. EXPECT ANY LINGERING SNOW
SHOWERS TO END BY LATE MORNING DOWNWIND OF THE MOUNTAINS WITH
PARTIAL CLEARING IN THE AFTERNOON AS STRONG NORTHWEST FLOW SETS UP
BEHIND THE FRONT. INCREASING UPSLOPE FLOW AND LOW LEVEL MOISTURE WILL
KEEP SNOW SHOWERS GOING IN THE MOUNTAINS. EXPECT HIGH TEMPS TO BE
REACHED IN THE MORNING BEFORE DROPPING BACK IN THE AFTERNOON.
HIGHS WILL RANGE FROM THE MID 20S TO LOWER 30S NORTH AND LOWER TO
MID 30S SOUTH.


&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
MODELS CONTINUE SUGGEST CHANGES TO THE NRN HEMISPHERE 500 MB
PATTERN....WITH SHORTER WAVELENGTHS IN THE FLOW...AND LESS
ESTABLISHED BLOCKING. THIS WILL GENERALLY MAKE FOR A MORE
PROGRESSIVE PATTERN...AND MAY ALLOW SOME WARMER AIR TO BEGIN TO
NUDGE POLEWARD. THE PROGRESSIVE PATTERN WILL ALSO LIMIT THE
DEVELOPMENT OF ANY SIGNIFICANT ERN CONUS STORMS.

MON EVE STARTS OFF WITH GUSTY NW FLOW AND SOME MN SHSN...BUT THE
WINDS AND SHSN WILL BEGIN TO DIMINISH BEFORE MIDNIGHT...AND
CONTINUE TO DO SO OVERNIGHT. SOME LATE RAD COOLING WILL ALLOW
TEMPS TO FALL TO AROUND ZERO IN THE NORTH...AND AROUND 10 ABOVE
ALONG THE COAST /WHICH COMPARED TO RECENTLY IS NOT AS COLD...BUT
STILL ABOUT 10 DEGREES BLO NORMAL/. TUE WILL START OFF SUNNY...BUT
INCREASING MID-HIGH CLOUDS OVERSPREAD THE REGION FROM SW-NE...WITH
AN CHANCE FOR SOME LIGHT SN IN SW NH LATE IN THE
AFTERNOON...ALTHOUGH IN GENERALLY THE PRECIP WILL HOLD OFF UNTIL
TUE NIGHT.

TUE NIGHT WILL SEE MAINLY WAA PRECIP STARTING OFF AS SNOW
CONTINUING THROUGH THE EVENING AND INTO THE EVENING. BY THE PRE-
DAWN HOURS WILL START TO ABV FREEZING AIR WORKING ALOFT...MAINLY
ACROSS THE SRN HALF OF NH AND SW ME....AND COULD SEE PRECIP CHANGE
OVER TO PL/FZRA FOR A TIME. HOWEVER...BULK OF THE OVERNIGHT WILL
BE SNOW...AND SEVERAL INCHES ARE POSSIBLE BEFORE ANY CHANGE IN THE
S AND W ZONES...AS WELL AS THE REST OF THE CWA WHERE SNOW
CONTINUES THRU THE NIGHT. OVERALL QPF ARE RUNNING 0.25-0.5" ATTM.
GENERALLY THE MODELS ARE MORE PROGRESSIVE WITH THIS FIRST WAVE AND
PRECIP MOVES OUT WED MORNING...ALTHOUGH IT COULD END AS A A
LITTLE FZRA OR JUST PLAIN RAIN ON THE COAST AND IN SRN NH AS TEMPS
WILL BE RISING THRU THE TUE NIGHT AND ON WED....WHEN HIGHS COULD
TOP AROUND 40 IN MANY SPOTS.

MODEL CONSENSUS WOULD KEEP THE WEAK COLD FRONT THAT MOVES THRU
LATE WED STALLED WELL TO OUR S...AND HAVE LITTLE IMPACT ON THE
AREA THU. HOWEVER...THE HEMI CMC LIFTS IT BACK FAR ENOUGH N TO
POSSIBLY BRUSH THE COAST WITH A LITTLE PRECIP...AND THE CMC HAS
BEEN PERFORMING WELL THIS WINTER...SO SOMETHING TO KEEP AN EYE ON
FOR NOW. EITHER WAY...THE KICKER TROUGH MOVES THROUGH ON THU AND
IT TURNS COLDER AGAIN FOR FRI AND SAT...ALTHOUGH HIGHS WILL GET
INTO THE 20S TO AROUND 30 FRI/SAT...THIS IS STILL 10 DEGREES OR
SO BLO NORMAL.

&&

.AVIATION /07Z SUNDAY THROUGH THURSDAY/...
SHORT TERM...MVFR/IFR CEILINGS/VSBY DEVELOPING THIS AFTERNOON AND
PERSISTING OVERNIGHT. BECOMING VFR ON MONDAY WITH AREAS OF MVFR
CEILINGS/VSBY IN THE MOUNTAINS.

LONG TERM...WILL LKLY SEE A PERIOD OF IFR AT ALL TERMINALS IN
SNOW TUE NIGHT INTO WED MORNING. KLEB/KCON/KMHT/KPWM ALL COULD SEE
A BRIEF PERIOD OF PL/FZRA LATE TUE NIGHT INTO EARLY WED.
IMPROVEMENT TO VFR EXPECTED WED AFTERNOON THROUGH THU.

&&

.MARINE...
SHORT TERM...NO FLAGS TODAY OR TONIGHT. GALES LIKELY ON MONDAY.

LONG TERM...GALES WILL LINGER INTO MON EVE...BUT SHOULD DIMINISH
DURING THE OVERNIGHT. THESE WINDS WILL BE USHERING ANOTHER ROUND
COLD AIR...AND FREEZING SPRAY IS LIKELY MON NIGHT INTO EARLY TUE.
SCA MAY BE NEEDED TUE NIGHT IN SW FLOW.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.

&&

$$



000
FXUS61 KGYX 010820
AFDGYX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
320 AM EST SUN MAR 1 2015

.SYNOPSIS...
LOW PRESSURE WILL MOVE IN FROM THE WEST TODAY AND WILL CROSS THE
REGION OVERNIGHT...PRODUCING SOME LIGHT SNOW. A STRONG NORTHWEST
FLOW WILL SET UP IN ITS WAKE ON MONDAY. HIGH PRESSURE WILL BUILD
IN FROM THE WEST MONDAY NIGHT AND WILL CREST OVER THE REGION EARLY
TUESDAY BEFORE MOVING OFFSHORE. LOW PRESSURE WILL SWING THROUGH
SOUTHERN CANADA TUESDAY NIGHT PUSHING A WARM NORTH ACROSS THE
REGION...AND PRODUCING A PERIOD OF SNOW...SLEET...OR FREEZING
RAIN. AS THE LOW SHIFT TO OUT NORTH...IT WILL DRAG A COLD FRONT
THROUGH THE REGION ON WEDNESDAY. HIGH PRESSURE WILL BUILD IN FROM
THE WEST THURSDAY AND WILL CREST OVER THE REGION ON FRIDAY.

&&

.NEAR TERM /THROUGH TODAY/...
CLOUDS WILL INCREASE AND THICKEN ACROSS THE REGION THIS MORNING
THROUGH MID AFTERNOON AS WEAK LOW PRESSURE PUSHES IN FROM THE
WEST. WILL SEE LIGHT SNOW BREAKING OUT IN NEW HAMPSHIRE DURING THE
MID TO LATE AFTERNOON AND THIS WILL PUSH EAST INTO WESTERN MAINE
THROUGH EARLY EVENING. ONLY LOOKING AT ACCUMULATIONS OF AN INCH OR
LESS THROUGH THE END OF THE DAY WITH MOST OF THAT IN SOUTHERN NEW
HAMPSHIRE. ONCE AGAIN TEMPERATURES WILL REMAIN BELOW NORMAL WITH
HIGH GENERALLY RANGING THROUGH THE 20S.

&&

.SHORT TERM /TONIGHT THROUGH 6 PM MONDAY/...
LIGHT SNOW WILL CONTINUE OVERNIGHT THROUGHOUT THE FORECAST AREA AS
LOW PRESSURE PUSHES THROUGH THE REGION. STORM TOTALS FOR MUCH OF
THE FORECAST AREA WILL BE IN THE 1 TO 3 INCH RANGE ALTHOUGH
SOUTHERN NEW HAMPSHIRE MAY SEE LOCALLY HIGHER AMOUNTS OF 2 TO 4
INCHES. LOWS TEMPS WILL BOTTOM OUT IN THE TEENS NORTH AND 20S
SOUTH.

TRAILING COLD FRONT WILL CROSS THE REGION MONDAY MORNING AS LOW
PRESSURE SHIFTS INTO THE MARITIMES. EXPECT ANY LINGERING SNOW
SHOWERS TO END BY LATE MORNING DOWNWIND OF THE MOUNTAINS WITH
PARTIAL CLEARING IN THE AFTERNOON AS STRONG NORTHWEST FLOW SETS UP
BEHIND THE FRONT. INCREASING UPSLOPE FLOW AND LOW LEVEL MOISTURE WILL
KEEP SNOW SHOWERS GOING IN THE MOUNTAINS. EXPECT HIGH TEMPS TO BE
REACHED IN THE MORNING BEFORE DROPPING BACK IN THE AFTERNOON.
HIGHS WILL RANGE FROM THE MID 20S TO LOWER 30S NORTH AND LOWER TO
MID 30S SOUTH.


&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
MODELS CONTINUE SUGGEST CHANGES TO THE NRN HEMISPHERE 500 MB
PATTERN....WITH SHORTER WAVELENGTHS IN THE FLOW...AND LESS
ESTABLISHED BLOCKING. THIS WILL GENERALLY MAKE FOR A MORE
PROGRESSIVE PATTERN...AND MAY ALLOW SOME WARMER AIR TO BEGIN TO
NUDGE POLEWARD. THE PROGRESSIVE PATTERN WILL ALSO LIMIT THE
DEVELOPMENT OF ANY SIGNIFICANT ERN CONUS STORMS.

MON EVE STARTS OFF WITH GUSTY NW FLOW AND SOME MN SHSN...BUT THE
WINDS AND SHSN WILL BEGIN TO DIMINISH BEFORE MIDNIGHT...AND
CONTINUE TO DO SO OVERNIGHT. SOME LATE RAD COOLING WILL ALLOW
TEMPS TO FALL TO AROUND ZERO IN THE NORTH...AND AROUND 10 ABOVE
ALONG THE COAST /WHICH COMPARED TO RECENTLY IS NOT AS COLD...BUT
STILL ABOUT 10 DEGREES BLO NORMAL/. TUE WILL START OFF SUNNY...BUT
INCREASING MID-HIGH CLOUDS OVERSPREAD THE REGION FROM SW-NE...WITH
AN CHANCE FOR SOME LIGHT SN IN SW NH LATE IN THE
AFTERNOON...ALTHOUGH IN GENERALLY THE PRECIP WILL HOLD OFF UNTIL
TUE NIGHT.

TUE NIGHT WILL SEE MAINLY WAA PRECIP STARTING OFF AS SNOW
CONTINUING THROUGH THE EVENING AND INTO THE EVENING. BY THE PRE-
DAWN HOURS WILL START TO ABV FREEZING AIR WORKING ALOFT...MAINLY
ACROSS THE SRN HALF OF NH AND SW ME....AND COULD SEE PRECIP CHANGE
OVER TO PL/FZRA FOR A TIME. HOWEVER...BULK OF THE OVERNIGHT WILL
BE SNOW...AND SEVERAL INCHES ARE POSSIBLE BEFORE ANY CHANGE IN THE
S AND W ZONES...AS WELL AS THE REST OF THE CWA WHERE SNOW
CONTINUES THRU THE NIGHT. OVERALL QPF ARE RUNNING 0.25-0.5" ATTM.
GENERALLY THE MODELS ARE MORE PROGRESSIVE WITH THIS FIRST WAVE AND
PRECIP MOVES OUT WED MORNING...ALTHOUGH IT COULD END AS A A
LITTLE FZRA OR JUST PLAIN RAIN ON THE COAST AND IN SRN NH AS TEMPS
WILL BE RISING THRU THE TUE NIGHT AND ON WED....WHEN HIGHS COULD
TOP AROUND 40 IN MANY SPOTS.

MODEL CONSENSUS WOULD KEEP THE WEAK COLD FRONT THAT MOVES THRU
LATE WED STALLED WELL TO OUR S...AND HAVE LITTLE IMPACT ON THE
AREA THU. HOWEVER...THE HEMI CMC LIFTS IT BACK FAR ENOUGH N TO
POSSIBLY BRUSH THE COAST WITH A LITTLE PRECIP...AND THE CMC HAS
BEEN PERFORMING WELL THIS WINTER...SO SOMETHING TO KEEP AN EYE ON
FOR NOW. EITHER WAY...THE KICKER TROUGH MOVES THROUGH ON THU AND
IT TURNS COLDER AGAIN FOR FRI AND SAT...ALTHOUGH HIGHS WILL GET
INTO THE 20S TO AROUND 30 FRI/SAT...THIS IS STILL 10 DEGREES OR
SO BLO NORMAL.

&&

.AVIATION /07Z SUNDAY THROUGH THURSDAY/...
SHORT TERM...MVFR/IFR CEILINGS/VSBY DEVELOPING THIS AFTERNOON AND
PERSISTING OVERNIGHT. BECOMING VFR ON MONDAY WITH AREAS OF MVFR
CEILINGS/VSBY IN THE MOUNTAINS.

LONG TERM...WILL LKLY SEE A PERIOD OF IFR AT ALL TERMINALS IN
SNOW TUE NIGHT INTO WED MORNING. KLEB/KCON/KMHT/KPWM ALL COULD SEE
A BRIEF PERIOD OF PL/FZRA LATE TUE NIGHT INTO EARLY WED.
IMPROVEMENT TO VFR EXPECTED WED AFTERNOON THROUGH THU.

&&

.MARINE...
SHORT TERM...NO FLAGS TODAY OR TONIGHT. GALES LIKELY ON MONDAY.

LONG TERM...GALES WILL LINGER INTO MON EVE...BUT SHOULD DIMINISH
DURING THE OVERNIGHT. THESE WINDS WILL BE USHERING ANOTHER ROUND
COLD AIR...AND FREEZING SPRAY IS LIKELY MON NIGHT INTO EARLY TUE.
SCA MAY BE NEEDED TUE NIGHT IN SW FLOW.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.

&&

$$




000
FXUS61 KBOX 010617
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
115 AM EST SUN MAR 1 2015

.SYNOPSIS...

A FAST MOVING LOW PRESSURE SYSTEM WILL BRING ACCUMULATING SNOW TO
THE REGION LATE SUNDAY INTO SUNDAY NIGHT...WITH THE HIGHEST AMOUNTS
EXPECTED SOUTH OF THE MASSACHUSETTS TURNPIKE AND AWAY FROM THE
IMMEDIATE SOUTH COAST. HIGH PRESSURE BRINGS DRY COLD AIR FOR THE
EARLY WEEK. LOW PRESSURE FROM NORTHERN CANADA AND ASSOCIATED LOW
FORMING OVER THE PLAINS MONDAY WILL MERGE...THEN PASS WEST AND
NORTH OF NEW ENGLAND. THIS WILL SWING A COLD FRONT ACROSS THE
REGION ON WEDNESDAY. DRY AND COLD WEATHER RETURNS FOR THE END OF
THE WEEK.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...

115 AM UPDATE...

CLEAR SKIES...LIGHT WINDS AND DEEP SNOW PACK WAS RESULTING IN
ANOTHER EXCELLENT NIGHT OF RADIATIONAL COOLING.  TEMPS ALREADY BELOW
ZERO IN SOME OF THE NORMALLY COLDEST OUTLYING LOCATIONS...WHILE THE
URBAN HEAT ISLAND OF BOSTON STILL HAD TEMPS IN THE LOWER 20S!

LOW TEMPS WILL BOTTOM OUT NEAR 10 BELOW ZERO ACROSS THE
NORMALLY COLDEST OUTLYING LOCATIONS.  OTHER AREAS THAT DO NOT
RADIATE AS WELL SUCH AS THE HIGHER TERRAIN/URBAN CENTERS WILL SEE
LOWS MAINLY IN THE SINGLE DIGITS...TO LOWER TEENS.

THESE LOW TEMPS WILL LIKELY OCCUR BY 4 OR 5 AM AND THEN LEVEL OFF OR
RISE BY DAYBREAK...AS SOME MID/HIGH LEVEL CLOUDINESS MOVES IN FROM
THE WEST.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM MONDAY/...
*/ SUNDAY MORNING INTO MIDDAY...

QUIET WEATHER. CLOUDS THICKENING AS WINDS INCREASE OUT OF THE S.
WILL SEE TEMPERATURES GRADUALLY MODERATE INTO THE MID- TO UPPER-20S.

*/ SUNDAY AFTERNOON INTO EARLY MONDAY MORNING...

1) HIGHLIGHTS...

 - SNOW SUNDAY AFTERNOON INTO MONDAY MORNING
 - GREATEST INTENSITY SUNDAY EVENING AND OVERNIGHT
 - 6+ INCH SNOWFALLS EXPECTED BUT EXACTLY WHERE REMAINS UNCERTAIN
 - ANNOYINGLY...FORECAST GUIDANCE CONTINUES TO WOBBLE

1) OVERVIEW...

BROAD ISENTROPIC OVER-RUNNING EVENT OF GULF MOISTURE ALONG THE 275-
295K SURFACES AMPLIFIED BY A N-STREAM IMPULSE DURING THE TIMEFRAME
POSSIBLY INVOKING AN AREA OF LOW PRESSURE THAT SKIRTS ALONG THE S-
COAST SUBSEQUENTLY ENHANCING LOW-LEVEL WIND PROFILE. LIGHT-MODERATE
SNOWFALL IS ANTICIPATED WITH LOCALLY HEAVIER AMOUNTS. THE INTENSE
PORTION OF SNOWFALL IS EXPECTED SUNDAY EVENING AND OVERNIGHT ENDING
EARLY MONDAY MORNING.

MODEL PREFERENCE GIVEN TO THE ECMWF/GFS/REGIONAL CANADIAN WHICH WILL
SERVE AS THE CONSENSUS OF GUIDANCE FOR THIS DISCUSSION. THE 28.12Z
NAM WAS CONSIDERED AN OUTLIER WITH ITS AGGRESSIVE-MODE AND SECONDARY
LOW DEVELOPMENT JUST OFFSHORE.

2) PRECIPITATION-TYPE...

EVALUATING THERMAL FIELDS...BLEND OF FORECAST CONSENSUS PUTS THE
-2C H925 ISOTHERM W-E ACROSS S-TIER OF CT/RI AND ACROSS SE MA WITH
THE 0C H85 ISOTHERM JUST S OF LONG-ISLAND AND NANTUCKET COASTLINES.
THE CONSENSUS OF 1000-850 MB CRITICAL THICKNESSES LAYS RIGHT ALONG
THE IMMEDIATE S-COAST OF LONG-ISLAND AND CAPE COD.

AN ALL SNOW-EVENT WHEN CONSIDERING DYNAMIC-COOLING/WETBULBING OF THE
LOW-LEVELS AHEAD OF THE EVENT. THERE IS PERHAPS A CHANCE OF A BRIEF
MIX-OVER TO RAIN/FREEZING RAIN ACROSS THE CAPE AND ISLANDS AS S-FLOW
AT THE SURFACE IS POSSIBLY ABLE TO NUDGE ABOVE-FREEZING TEMPERATURES
N. YET AS WE ARE IN A FROZEN TUNDRA...WITH ANY RAIN IT WOULD LIKELY
FREEZE ON SURFACES WHICH ARE QUITE COLD. THUS FREEZING RAIN PREVAILS
OVER RAIN IN THE FORECAST.

3) SNOWFALL...

FORECAST CONSENSUS OF A 0.3-0.6 N-S PRECIPITATION EVENT WITH A N-S
SNOW-TO-LIQUID RATIO GRADIENT RANGING FROM 15:1 TO 10:1 YIELDS HIGH-
END SNOW ADVISORY CRITERIA WITH SNOWFALL AMOUNTS RANGING ON AVERAGE
AROUND 3-6 INCHES. AREAS OF 6+ INCHES ARE EXPECTED...ESPECIALLY FROM
CENTRAL-CT E INTO SE-MA /INCLUDING THE UPPER-CAPE/. A CHALLENGE AND
A LOT OF UNCERTAINTY WITH RESPECT TO HEADLINES AND DECISION-MAKING.

EVALUATING LOW-LEVEL THERMAL PROFILES TOWARDS SNOW-TO-LIQUID RATIOS
DERIVED VIA A COBB-TECHNIQUE...WITH THE GREATEST LIFT OCCURRING
JUST BENEATH OR WITHIN THE DENDRITIC-GROWTH ZONE BASED ON A
CONSENSUS OF BUFKIT GFS PROFILES...ESPECIALLY IN HEAVIER- PRECIP
AREAS...BELIEVE THE SNOW WILL RANGE SOMEWHERE BETWEEN A WET AND
FLUFFY SNOW. SNOW PROPERTIES FROM FLUFFY TO WET LIKELY SIMILAR TO
THE N-S GRADIENT AS OUTLINED ABOVE.

4) HEADLINES...

HATE A WOBBLING FORECAST WHICH IS TYPICAL WITH SUCH SMALL EVENTS.
UNCERTAINTY DERIVES FROM LOW-LEVEL THERMAL PROFILES AND PRECIP
AMOUNTS. SURELY EXPECTING SNOW...BUT WITH ANY SHIFT N-S OF COLDER
AIR AND/OR PRECIPITATION AMOUNTS RESULTS IN AREAS SHIFTING FROM
ADVISORY TO WARNING...OR VICE VERSA. ENOUGH TO JUST PULL YOUR HAIR
OUT. THEN THERE IS THE TIMING OF THE SYSTEM THAT HAS SPED UP
SLIGHTLY. A SHORTER RESIDENCE TIME OF COURSE WOULD YIELD LESSER
SNOWFALL AMOUNTS. QUITE A CHALLENGING FORECAST RIGHT ON THE CUSP
OF HEADLINE THRESHOLDS.

THE EVENT DOES TAKE PLACE MAINLY FROM SUNDAY EVENING INTO THE EARLY
MORNING HOURS ON MONDAY DURING WHICH TIME THERE IS NOT MUCH TRAFFIC
ON THE ROAD. IS THIS A HIGH IMPACT EVENT THAT WARRANTS WARNINGS? A
QUESTION TO STRUGGLE WITH AS WARNINGS ARE NECESSARY WHEN WE ARE
CONFIDENT IN MEETING OR EXCEEDING 6+ INCH CRITERIA. YET THE QUESTION
IN FRONT OF US IS WHERE WILL THE HIGHER AMOUNTS OF SNOW FOCUS? HAVE
TO MAKE SOME SORT OF CALL...THE NEEDS OF THE MANY OUTWEIGH THE NEEDS
OF THE FEW.

ADVISORIES POSTED WHERE THERE IS HIGH CONFIDENCE OF SNOW BUT LIKELY
TO REMAIN BELOW THE 6-INCH THRESHOLD FOR WARNING. WATCHES CONTINUE
AND HAVE BEEN EXTENDED TO THE S-COAST TO COVER FOR THE UNCERTAINTY
OF THE AREA EITHER FALLING WITHIN OR IN EXCESS OF ADVISORY-LEVEL
SNOWS. AGAIN...6+ INCH AMOUNTS ARE ANTICIPATED BUT EXACTLY WHERE IS
UNCERTAIN.

5) CLOSING NOTES...

SOME CONCERN FOR THE EARLY MONDAY MORNING COMMUTE FOR E/SE MA AND
RI. WHILE MOST OF THE SNOW IS EXPECTED TO BE IMMEDIATELY OFFSHORE
WITH SUNRISE MONDAY...COMMUTERS COULD ENCOUNTER SLICK AND SLIPPERY
ROAD CONDITIONS. SNOW COULD POSSIBLY LINGER OVER SE MA SO THERE IS
THE POTENTIAL FOR REDUCED VISIBILITIES.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
BIG PICTURE... THE BROAD UPPER FLOW SHOWS A RIDGE IN THE EAST AND
TROUGH IN THE WEST WITH A WEST SOUTHWEST FLOW FROM THE PLAINS TO THE
EASTERN USA COAST. WITHIN THIS FLOW ARE BOTH NORTHERN AND SOUTHERN
STREAMS AT THE START OF THE WEEK. THE WESTERN TROUGH MIGRATES EAST
DURING THE MIDWEEK AT WHICH TIME THE TWO STREAMS MERGE TO FORM A 140-
160 KT UPPER JET FEEDING NORTHEAST INTO THE GREAT LAKES AND ST
LAWRENCE VALLEY. THIS JET LINGERS OVER OR NEAR NEW ENGLAND THURSDAY-
FRIDAY BEFORE MOVING OFF. THE WESTERN TROUGH MOVES ACROSS NEW
ENGLAND BY THE END OF THE WEEK.

DAILIES...

MONDAY... SUNDAY STORM MOVES OFF PAST NOVA SCOTIA WHILE THE
SUPPORTING UPPER SHORTWAVE AND COLD POOL SWING ACROSS NEW ENGLAND.
THE COOLEST AIR ALOFT IS IN NORTHERN NEW ENGLAND WHILE LEFTOVER
MOISTURE LINGERS BELOW 800 MB THROUGH THE DAY. THE GFS IS FASTER
THAN THE ECMWF IN BRINGING RISING PRESSURE TO THE REGION BUT HAVE 1
MB/HOUR RISES HERE BY EVENING. PUT TOGETHER...EXPECT A CLEARING
TREND BUT WITH LEFTOVER CLOUDS ESPECIALLY NORTH OF THE MASS PIKE.
SUSTAINED NORTHWEST WINDS SHOULD RISE TO 15-20 KTS. MIXING REACHES
TO AT LEAST 850 MB AND POSSIBLY A LITTLE HIGHER...WHICH SUPPORTS
GUSTS TO AT LEAST 30 KNOTS AND POSSIBLY 35 KNOTS. TEMPS AT 850 MB
WILL BE -11C TO -14C...MIXING THIS TO THE SURFACE WOULD SUPPORT MAX
SFC TEMPS IN THE 30S. MIN TEMPERATURES UPSTREAM THIS MORNING WERE IN
THE SINGLE NUMBERS WITH A FEW SPOTS BELOW ZERO. WITH LIGHT PRESSURE
GRADIENT ESP IN THE WEST...WE TENDED A FEW DEGREES COOLER THAN
CONSENSUS.

TUESDAY-WEDNESDAY... HIGH PRESSURE IN CONTROL MUCH OF TUESDAY BUT
MOVING OFFSHORE DURING THE AFTERNOON. CROSS SECTIONS SHOW INCREASING
MOISTURE AT MID AND HIGH CLOUD LEVEL...SO INCREASING HIGH CLOUDS.
SYSTEM MOVING INTO THE GREAT LAKES SPREADS PCPN INTO NEW YORK...BUT
WARM ADVECTION LIFT REMAINS MOSTLY TO OUR WEST THROUGH THE
AFTERNOON. SOME LIFT FORECAST AT 290K /ABOUT 730 MB AT THE TIME/ BUT
NONE BELOW THAT. MEANWHILE DEWPOINTS IN THE SINGLE NUMBERS PROGRESS
INTO THE TEENS DURING THE DAY...BUT ENOUGH OF A TEMP/DEWPOINT SPREAD
TO SLOW THE ADVANCE OF ANY PCPN FROM THE CLOUDS BY A FEW HOURS.

WARM ADVECTION LIFT MUCH OF THE NIGHT SUPPORTS THE IDEA OF PCPN.
TEMPERATURES START COLD DURING THE EVENING BUT SHOULD RISE
OVERNIGHT. THE QUESTION REMAINS AS TO HOW HIGH THEY WILL CLIMB. EVEN
WITH THE SURFACE SYSTEM TRACKING UP THE ST LAWRENCE VALLEY THERE IS
COLD GROUND AND A COLD SNOWPACK. THIS WOULD ALLOW THE WARMER TEMPS
TO SCREAM OVERHEAD WHILE THE IMMEDIATE SURFACE REMAINS SEVERAL
DEGREES COLDER. WE TRIMMED TEMPS BACK A LITTLE FROM MODEL
VALUES...BUT LOW CONFIDENCE AT THIS TIME DUE TO THE POTENTIAL THAT
SURFACE TEMPS COULD REMAIN IN THE 30S.

QPF FORECASTS RANGE FROM 0.50 TO 1.00 INCHES WITH THE HIGHER AMOUNTS
TENDING TOWARD THE SOUTH COAST. THIS POINTS TO A MESSY STORM WITH
INITIAL SNOW ACCUMS OF SEVERAL INCHES FOLLOWED BY A CHANGE TO
MEASURABLE ICE ACCUMULATION AND THEN A CHANGE TO RAIN WITH
POTENTIAL FOR POOR DRAINAGE FLOODING IN BETWEEN THE SNOW BANKS.

THE COLD FRONT SHOULD MOVE THROUGH DURING THE AFTERNOON/EVENING WITH
A SHIFT TO NORTHWEST WINDS. THIS WILL CHANGE THE PCPN BACK TO SNOW
BEFORE TAPERING OFF.

THURSDAY...DIFFERENCES IN THE GFS AND ECMWF IN HANDING THE UPPER JET.
THE ECMWF MOVES THE JET OFFSHORE AND PUTS SOUTHERN NEW ENGLAND
INTO SUBSIDENCE. THE GFS MAINTAINS THE JET OVERHEAD WITH OUR AREA
IN THE RIGHT ENTRANCE REGION. THE FIRST SCENARIO ENDS THE PCPN AND
COOLS THE AIR. THE SECOND SCENARIO WOULD SUPPORT LIFT AND GENERATE
WAVES ALONG THE DEPARTING COLD FRONT...MAINTAINING A CHANCE OF
SNOW OVER AT LEAST SOUTHERN PARTS OF OUR AREA. OUR THURSDAY
FORECAST TENDS TOWARD THE LATTER FOR NOW.

FRIDAY-SATURDAY... HIGH PRESSURE BUILDS OVER THE REGION THURSDAY
NIGHT AND FRIDAY WITH CLEARING SKIES AND A BRIEF PERIOD OF COLD AIR.
TEMPS ALOFT TREND UP ABOUT 10C ON SATURDAY SUGGESTING LESS CHILL AT
THE SURFACE. ANOTHER COLD FRONT APPROACHES THE ST LAWRENCE VALLEY
AND COULD SPREAD SOME CLOUDS INTO OUR AREA SATURDAY
AFTERNOON/EVENING. BUT PCPN CHANCES LOOK SMALL.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TODAY AND TONIGHT/...

TODAY AND TONIGHT...MODERATE CONFIDENCE.  VFR CONDITIONS THROUGH AT
LEAST MID MORNING.  SOME MVFR TO IFR CONDITIONS DEVELOP FROM WEST TO
EAST LATE THIS MORNING AND THIS AFTERNOON IN AREAS OF LIGHT SNOW.
HOWEVER...THE BULK OF THE MODERATE TO EVEN BRIEFLY HEAVY SNOW WILL
OCCUR THIS EVENING WHEN WIDESPREAD IFR TO LIFR CONDITIONS OCCUR.
THE LOWER CONDITIONS MOST LIKELY SOUTH OF THE MA TURNPIKE.  PTYPE
PRETTY MUCH ALL SNOW...EXCEPT FOR THE VERY IMMEDIATE SOUTH
COAST/CAPE WHERE SNOW MAY MIX WITH OR CHANGE TO RAIN FOR A TIME.
WHETHER OR NOT THAT HAPPENS IS UNCERTAIN...BUT WE DO THINK THAT AT
LEAST THE ISLANDS WILL CHANGE TO RAIN.

BULK OF SNOW ENDS BY 8 OR 9Z TONIGHT AND MUCH OF THE THE REGION
SHOULD ALREADY HAVE VFR CONDITIONS BY 12Z MONDAY.

KBOS TAF...CONFIDENT IN OVERALL TRENDS BUT EXACT TIMING IS MORE
UNCERTAIN.  WHILE SOME LIGHT SNOW IS POSSIBLE THIS
AFTERNOON...BULK OF ACCUMULATING SNOW WITH WIDESPREAD IFR TO LIFR
CONDITIONS EXPECTED THIS EVENING.

KBDL TAF...CONFIDENT IN OVERALL TRENDS BUT EXACT TIMING IS MORE
UNCERTAIN.  WHILE SOME LIGHT SNOW IS POSSIBLE LATE THIS MORNING AND
AFTERNOON...BULK OF ACCUMULATING SNOW WITH WIDESPREAD IFR TO LIFR
CONDITIONS EXPECTED AFTER 3 OR 4 PM.

OUTLOOK...MONDAY THROUGH THURSDAY...

MONDAY... HIGH CONFIDENCE. SOME IFR/MVFR IN SNOW EARLY MORNING BUT
OTHERWISE CONDITIONS WILL IMPROVE TO VFR DURING THE MORNING.
NORTHWEST WINDS WILL INCREASE WITH GUSTS AROUND 30 KNOTS BY MIDDAY.
VFR AND DIMINISHING WIND MONDAY NIGHT.

TUESDAY...MODERATE CONFIDENCE. VFR DURING THE DAY WITH INCREASING
SKY COVER. MVFR TUESDAY EVENING BECOMING IFR/LIFR OVERNIGHT IN
DEVELOPING SNOW AND FREEZING RAIN.

WEDNESDAY...MODERATE CONFIDENCE. IFR/LIFR IN RAIN AND FREEZING RAIN.

THURSDAY...LOW CONFIDENCE. VFR NORTH OF A HFD-BOS LINE. MVFR CIGS
AND AREAS OF MVFR/IFR VSBYS IN SNOW.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /THROUGH MONDAY MORNING/...HIGH CONFIDENCE.

HIGH PRESSURE NEARBY WILL KEEP WINDS/SEAS WELL BELOW SMALL CRAFT
ADVISORY THRESHOLDS INTO SUNDAY MORNING. A WEAK WAVE OF LOW
PRESSURE MOVES ACROSS THE WATERS LATE SUNDAY INTO SUNDAY NIGHT...
BUT WEAK PRESSURE GRADIENT SHOULD KEEP WINDS/SEAS BELOW SMALL
CRAFT THRESHOLDS.

OUTLOOK...MONDAY THROUGH THURSDAY..MODERATE CONFIDENCE.

MONDAY...WEST TO NORTHWEST WINDS INCREASE WITH FREQUENT GUSTS TO
GALE FORCE ESPECIALLY AWAY FROM THE NEARSHORE. THIS COULD GENERATE
SOME LIGHT FREEZING SPRAY ESPECIALLY EARLY MONDAY NIGHT. SEAS 5
TO 10 FEET. WINDS AND SEAS DIMINISH MONDAY NIGHT. A GALE WARNING
MAY BE NEEDED.

TUESDAY... LINGERING 5 FOOT SEAS ON THE OUTER WATERS BUT DIMINISHING
DURING THE MORNING.  WINDS AND SEAS INCREASE AGAIN TUESDAY NIGHT
AFTER MIDNIGHT AHEAD OF A GREAT LAKES COLD FRONT. SOUTH WINDS WILL
APPROACH 25 KNOTS WITH SEAS BUILDING TO 5 TO 8 FEET. VSBYS WILL
BE REDUCED IN SNOW CHANGING TO RAIN.

WEDNESDAY...SOUTHWEST WINDS WITH GUSTS 25-30 KNOTS.  SEAS BUILDING
TO 6 TO 12 FEET. REDUCED VSBYS IN RAIN. A SMALL CRAFT ADVISORY MAY
BE NEEDED.

THURSDAY...NORTHWEST WINDS WILL GUST TO 25 KNOTS...AND SEAS 5 TO 8
FEET. BOTH SHOULD DIMINISH TOWARD EVENING.  A SMALL CRAFT ADVISORY
MAY BE NEEDED.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WINTER STORM WATCH FROM NOON EST TODAY THROUGH MONDAY MORNING
     FOR CTZ002>004.
MA...WINTER WEATHER ADVISORY FROM NOON TODAY TO 7 AM EST MONDAY FOR
     MAZ002>008-010-014-023-024-026.
     WINTER STORM WATCH FROM NOON EST TODAY THROUGH MONDAY MORNING
     FOR MAZ009-011>013-015>022.
RI...WINTER WEATHER ADVISORY FROM NOON TODAY TO 7 AM EST MONDAY FOR
     RIZ008.
     WINTER STORM WATCH FROM NOON EST TODAY THROUGH MONDAY MORNING
     FOR RIZ001>007.
MARINE...NONE.

&&

$$
SYNOPSIS...WTB/SIPPRELL
NEAR TERM...FRANK
SHORT TERM...SIPPRELL
LONG TERM...WTB
AVIATION...FRANK/WTB
MARINE...WTB/SIPPRELL



000
FXUS61 KBOX 010617
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
115 AM EST SUN MAR 1 2015

.SYNOPSIS...

A FAST MOVING LOW PRESSURE SYSTEM WILL BRING ACCUMULATING SNOW TO
THE REGION LATE SUNDAY INTO SUNDAY NIGHT...WITH THE HIGHEST AMOUNTS
EXPECTED SOUTH OF THE MASSACHUSETTS TURNPIKE AND AWAY FROM THE
IMMEDIATE SOUTH COAST. HIGH PRESSURE BRINGS DRY COLD AIR FOR THE
EARLY WEEK. LOW PRESSURE FROM NORTHERN CANADA AND ASSOCIATED LOW
FORMING OVER THE PLAINS MONDAY WILL MERGE...THEN PASS WEST AND
NORTH OF NEW ENGLAND. THIS WILL SWING A COLD FRONT ACROSS THE
REGION ON WEDNESDAY. DRY AND COLD WEATHER RETURNS FOR THE END OF
THE WEEK.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...

115 AM UPDATE...

CLEAR SKIES...LIGHT WINDS AND DEEP SNOW PACK WAS RESULTING IN
ANOTHER EXCELLENT NIGHT OF RADIATIONAL COOLING.  TEMPS ALREADY BELOW
ZERO IN SOME OF THE NORMALLY COLDEST OUTLYING LOCATIONS...WHILE THE
URBAN HEAT ISLAND OF BOSTON STILL HAD TEMPS IN THE LOWER 20S!

LOW TEMPS WILL BOTTOM OUT NEAR 10 BELOW ZERO ACROSS THE
NORMALLY COLDEST OUTLYING LOCATIONS.  OTHER AREAS THAT DO NOT
RADIATE AS WELL SUCH AS THE HIGHER TERRAIN/URBAN CENTERS WILL SEE
LOWS MAINLY IN THE SINGLE DIGITS...TO LOWER TEENS.

THESE LOW TEMPS WILL LIKELY OCCUR BY 4 OR 5 AM AND THEN LEVEL OFF OR
RISE BY DAYBREAK...AS SOME MID/HIGH LEVEL CLOUDINESS MOVES IN FROM
THE WEST.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM MONDAY/...
*/ SUNDAY MORNING INTO MIDDAY...

QUIET WEATHER. CLOUDS THICKENING AS WINDS INCREASE OUT OF THE S.
WILL SEE TEMPERATURES GRADUALLY MODERATE INTO THE MID- TO UPPER-20S.

*/ SUNDAY AFTERNOON INTO EARLY MONDAY MORNING...

1) HIGHLIGHTS...

 - SNOW SUNDAY AFTERNOON INTO MONDAY MORNING
 - GREATEST INTENSITY SUNDAY EVENING AND OVERNIGHT
 - 6+ INCH SNOWFALLS EXPECTED BUT EXACTLY WHERE REMAINS UNCERTAIN
 - ANNOYINGLY...FORECAST GUIDANCE CONTINUES TO WOBBLE

1) OVERVIEW...

BROAD ISENTROPIC OVER-RUNNING EVENT OF GULF MOISTURE ALONG THE 275-
295K SURFACES AMPLIFIED BY A N-STREAM IMPULSE DURING THE TIMEFRAME
POSSIBLY INVOKING AN AREA OF LOW PRESSURE THAT SKIRTS ALONG THE S-
COAST SUBSEQUENTLY ENHANCING LOW-LEVEL WIND PROFILE. LIGHT-MODERATE
SNOWFALL IS ANTICIPATED WITH LOCALLY HEAVIER AMOUNTS. THE INTENSE
PORTION OF SNOWFALL IS EXPECTED SUNDAY EVENING AND OVERNIGHT ENDING
EARLY MONDAY MORNING.

MODEL PREFERENCE GIVEN TO THE ECMWF/GFS/REGIONAL CANADIAN WHICH WILL
SERVE AS THE CONSENSUS OF GUIDANCE FOR THIS DISCUSSION. THE 28.12Z
NAM WAS CONSIDERED AN OUTLIER WITH ITS AGGRESSIVE-MODE AND SECONDARY
LOW DEVELOPMENT JUST OFFSHORE.

2) PRECIPITATION-TYPE...

EVALUATING THERMAL FIELDS...BLEND OF FORECAST CONSENSUS PUTS THE
-2C H925 ISOTHERM W-E ACROSS S-TIER OF CT/RI AND ACROSS SE MA WITH
THE 0C H85 ISOTHERM JUST S OF LONG-ISLAND AND NANTUCKET COASTLINES.
THE CONSENSUS OF 1000-850 MB CRITICAL THICKNESSES LAYS RIGHT ALONG
THE IMMEDIATE S-COAST OF LONG-ISLAND AND CAPE COD.

AN ALL SNOW-EVENT WHEN CONSIDERING DYNAMIC-COOLING/WETBULBING OF THE
LOW-LEVELS AHEAD OF THE EVENT. THERE IS PERHAPS A CHANCE OF A BRIEF
MIX-OVER TO RAIN/FREEZING RAIN ACROSS THE CAPE AND ISLANDS AS S-FLOW
AT THE SURFACE IS POSSIBLY ABLE TO NUDGE ABOVE-FREEZING TEMPERATURES
N. YET AS WE ARE IN A FROZEN TUNDRA...WITH ANY RAIN IT WOULD LIKELY
FREEZE ON SURFACES WHICH ARE QUITE COLD. THUS FREEZING RAIN PREVAILS
OVER RAIN IN THE FORECAST.

3) SNOWFALL...

FORECAST CONSENSUS OF A 0.3-0.6 N-S PRECIPITATION EVENT WITH A N-S
SNOW-TO-LIQUID RATIO GRADIENT RANGING FROM 15:1 TO 10:1 YIELDS HIGH-
END SNOW ADVISORY CRITERIA WITH SNOWFALL AMOUNTS RANGING ON AVERAGE
AROUND 3-6 INCHES. AREAS OF 6+ INCHES ARE EXPECTED...ESPECIALLY FROM
CENTRAL-CT E INTO SE-MA /INCLUDING THE UPPER-CAPE/. A CHALLENGE AND
A LOT OF UNCERTAINTY WITH RESPECT TO HEADLINES AND DECISION-MAKING.

EVALUATING LOW-LEVEL THERMAL PROFILES TOWARDS SNOW-TO-LIQUID RATIOS
DERIVED VIA A COBB-TECHNIQUE...WITH THE GREATEST LIFT OCCURRING
JUST BENEATH OR WITHIN THE DENDRITIC-GROWTH ZONE BASED ON A
CONSENSUS OF BUFKIT GFS PROFILES...ESPECIALLY IN HEAVIER- PRECIP
AREAS...BELIEVE THE SNOW WILL RANGE SOMEWHERE BETWEEN A WET AND
FLUFFY SNOW. SNOW PROPERTIES FROM FLUFFY TO WET LIKELY SIMILAR TO
THE N-S GRADIENT AS OUTLINED ABOVE.

4) HEADLINES...

HATE A WOBBLING FORECAST WHICH IS TYPICAL WITH SUCH SMALL EVENTS.
UNCERTAINTY DERIVES FROM LOW-LEVEL THERMAL PROFILES AND PRECIP
AMOUNTS. SURELY EXPECTING SNOW...BUT WITH ANY SHIFT N-S OF COLDER
AIR AND/OR PRECIPITATION AMOUNTS RESULTS IN AREAS SHIFTING FROM
ADVISORY TO WARNING...OR VICE VERSA. ENOUGH TO JUST PULL YOUR HAIR
OUT. THEN THERE IS THE TIMING OF THE SYSTEM THAT HAS SPED UP
SLIGHTLY. A SHORTER RESIDENCE TIME OF COURSE WOULD YIELD LESSER
SNOWFALL AMOUNTS. QUITE A CHALLENGING FORECAST RIGHT ON THE CUSP
OF HEADLINE THRESHOLDS.

THE EVENT DOES TAKE PLACE MAINLY FROM SUNDAY EVENING INTO THE EARLY
MORNING HOURS ON MONDAY DURING WHICH TIME THERE IS NOT MUCH TRAFFIC
ON THE ROAD. IS THIS A HIGH IMPACT EVENT THAT WARRANTS WARNINGS? A
QUESTION TO STRUGGLE WITH AS WARNINGS ARE NECESSARY WHEN WE ARE
CONFIDENT IN MEETING OR EXCEEDING 6+ INCH CRITERIA. YET THE QUESTION
IN FRONT OF US IS WHERE WILL THE HIGHER AMOUNTS OF SNOW FOCUS? HAVE
TO MAKE SOME SORT OF CALL...THE NEEDS OF THE MANY OUTWEIGH THE NEEDS
OF THE FEW.

ADVISORIES POSTED WHERE THERE IS HIGH CONFIDENCE OF SNOW BUT LIKELY
TO REMAIN BELOW THE 6-INCH THRESHOLD FOR WARNING. WATCHES CONTINUE
AND HAVE BEEN EXTENDED TO THE S-COAST TO COVER FOR THE UNCERTAINTY
OF THE AREA EITHER FALLING WITHIN OR IN EXCESS OF ADVISORY-LEVEL
SNOWS. AGAIN...6+ INCH AMOUNTS ARE ANTICIPATED BUT EXACTLY WHERE IS
UNCERTAIN.

5) CLOSING NOTES...

SOME CONCERN FOR THE EARLY MONDAY MORNING COMMUTE FOR E/SE MA AND
RI. WHILE MOST OF THE SNOW IS EXPECTED TO BE IMMEDIATELY OFFSHORE
WITH SUNRISE MONDAY...COMMUTERS COULD ENCOUNTER SLICK AND SLIPPERY
ROAD CONDITIONS. SNOW COULD POSSIBLY LINGER OVER SE MA SO THERE IS
THE POTENTIAL FOR REDUCED VISIBILITIES.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
BIG PICTURE... THE BROAD UPPER FLOW SHOWS A RIDGE IN THE EAST AND
TROUGH IN THE WEST WITH A WEST SOUTHWEST FLOW FROM THE PLAINS TO THE
EASTERN USA COAST. WITHIN THIS FLOW ARE BOTH NORTHERN AND SOUTHERN
STREAMS AT THE START OF THE WEEK. THE WESTERN TROUGH MIGRATES EAST
DURING THE MIDWEEK AT WHICH TIME THE TWO STREAMS MERGE TO FORM A 140-
160 KT UPPER JET FEEDING NORTHEAST INTO THE GREAT LAKES AND ST
LAWRENCE VALLEY. THIS JET LINGERS OVER OR NEAR NEW ENGLAND THURSDAY-
FRIDAY BEFORE MOVING OFF. THE WESTERN TROUGH MOVES ACROSS NEW
ENGLAND BY THE END OF THE WEEK.

DAILIES...

MONDAY... SUNDAY STORM MOVES OFF PAST NOVA SCOTIA WHILE THE
SUPPORTING UPPER SHORTWAVE AND COLD POOL SWING ACROSS NEW ENGLAND.
THE COOLEST AIR ALOFT IS IN NORTHERN NEW ENGLAND WHILE LEFTOVER
MOISTURE LINGERS BELOW 800 MB THROUGH THE DAY. THE GFS IS FASTER
THAN THE ECMWF IN BRINGING RISING PRESSURE TO THE REGION BUT HAVE 1
MB/HOUR RISES HERE BY EVENING. PUT TOGETHER...EXPECT A CLEARING
TREND BUT WITH LEFTOVER CLOUDS ESPECIALLY NORTH OF THE MASS PIKE.
SUSTAINED NORTHWEST WINDS SHOULD RISE TO 15-20 KTS. MIXING REACHES
TO AT LEAST 850 MB AND POSSIBLY A LITTLE HIGHER...WHICH SUPPORTS
GUSTS TO AT LEAST 30 KNOTS AND POSSIBLY 35 KNOTS. TEMPS AT 850 MB
WILL BE -11C TO -14C...MIXING THIS TO THE SURFACE WOULD SUPPORT MAX
SFC TEMPS IN THE 30S. MIN TEMPERATURES UPSTREAM THIS MORNING WERE IN
THE SINGLE NUMBERS WITH A FEW SPOTS BELOW ZERO. WITH LIGHT PRESSURE
GRADIENT ESP IN THE WEST...WE TENDED A FEW DEGREES COOLER THAN
CONSENSUS.

TUESDAY-WEDNESDAY... HIGH PRESSURE IN CONTROL MUCH OF TUESDAY BUT
MOVING OFFSHORE DURING THE AFTERNOON. CROSS SECTIONS SHOW INCREASING
MOISTURE AT MID AND HIGH CLOUD LEVEL...SO INCREASING HIGH CLOUDS.
SYSTEM MOVING INTO THE GREAT LAKES SPREADS PCPN INTO NEW YORK...BUT
WARM ADVECTION LIFT REMAINS MOSTLY TO OUR WEST THROUGH THE
AFTERNOON. SOME LIFT FORECAST AT 290K /ABOUT 730 MB AT THE TIME/ BUT
NONE BELOW THAT. MEANWHILE DEWPOINTS IN THE SINGLE NUMBERS PROGRESS
INTO THE TEENS DURING THE DAY...BUT ENOUGH OF A TEMP/DEWPOINT SPREAD
TO SLOW THE ADVANCE OF ANY PCPN FROM THE CLOUDS BY A FEW HOURS.

WARM ADVECTION LIFT MUCH OF THE NIGHT SUPPORTS THE IDEA OF PCPN.
TEMPERATURES START COLD DURING THE EVENING BUT SHOULD RISE
OVERNIGHT. THE QUESTION REMAINS AS TO HOW HIGH THEY WILL CLIMB. EVEN
WITH THE SURFACE SYSTEM TRACKING UP THE ST LAWRENCE VALLEY THERE IS
COLD GROUND AND A COLD SNOWPACK. THIS WOULD ALLOW THE WARMER TEMPS
TO SCREAM OVERHEAD WHILE THE IMMEDIATE SURFACE REMAINS SEVERAL
DEGREES COLDER. WE TRIMMED TEMPS BACK A LITTLE FROM MODEL
VALUES...BUT LOW CONFIDENCE AT THIS TIME DUE TO THE POTENTIAL THAT
SURFACE TEMPS COULD REMAIN IN THE 30S.

QPF FORECASTS RANGE FROM 0.50 TO 1.00 INCHES WITH THE HIGHER AMOUNTS
TENDING TOWARD THE SOUTH COAST. THIS POINTS TO A MESSY STORM WITH
INITIAL SNOW ACCUMS OF SEVERAL INCHES FOLLOWED BY A CHANGE TO
MEASURABLE ICE ACCUMULATION AND THEN A CHANGE TO RAIN WITH
POTENTIAL FOR POOR DRAINAGE FLOODING IN BETWEEN THE SNOW BANKS.

THE COLD FRONT SHOULD MOVE THROUGH DURING THE AFTERNOON/EVENING WITH
A SHIFT TO NORTHWEST WINDS. THIS WILL CHANGE THE PCPN BACK TO SNOW
BEFORE TAPERING OFF.

THURSDAY...DIFFERENCES IN THE GFS AND ECMWF IN HANDING THE UPPER JET.
THE ECMWF MOVES THE JET OFFSHORE AND PUTS SOUTHERN NEW ENGLAND
INTO SUBSIDENCE. THE GFS MAINTAINS THE JET OVERHEAD WITH OUR AREA
IN THE RIGHT ENTRANCE REGION. THE FIRST SCENARIO ENDS THE PCPN AND
COOLS THE AIR. THE SECOND SCENARIO WOULD SUPPORT LIFT AND GENERATE
WAVES ALONG THE DEPARTING COLD FRONT...MAINTAINING A CHANCE OF
SNOW OVER AT LEAST SOUTHERN PARTS OF OUR AREA. OUR THURSDAY
FORECAST TENDS TOWARD THE LATTER FOR NOW.

FRIDAY-SATURDAY... HIGH PRESSURE BUILDS OVER THE REGION THURSDAY
NIGHT AND FRIDAY WITH CLEARING SKIES AND A BRIEF PERIOD OF COLD AIR.
TEMPS ALOFT TREND UP ABOUT 10C ON SATURDAY SUGGESTING LESS CHILL AT
THE SURFACE. ANOTHER COLD FRONT APPROACHES THE ST LAWRENCE VALLEY
AND COULD SPREAD SOME CLOUDS INTO OUR AREA SATURDAY
AFTERNOON/EVENING. BUT PCPN CHANCES LOOK SMALL.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TODAY AND TONIGHT/...

TODAY AND TONIGHT...MODERATE CONFIDENCE.  VFR CONDITIONS THROUGH AT
LEAST MID MORNING.  SOME MVFR TO IFR CONDITIONS DEVELOP FROM WEST TO
EAST LATE THIS MORNING AND THIS AFTERNOON IN AREAS OF LIGHT SNOW.
HOWEVER...THE BULK OF THE MODERATE TO EVEN BRIEFLY HEAVY SNOW WILL
OCCUR THIS EVENING WHEN WIDESPREAD IFR TO LIFR CONDITIONS OCCUR.
THE LOWER CONDITIONS MOST LIKELY SOUTH OF THE MA TURNPIKE.  PTYPE
PRETTY MUCH ALL SNOW...EXCEPT FOR THE VERY IMMEDIATE SOUTH
COAST/CAPE WHERE SNOW MAY MIX WITH OR CHANGE TO RAIN FOR A TIME.
WHETHER OR NOT THAT HAPPENS IS UNCERTAIN...BUT WE DO THINK THAT AT
LEAST THE ISLANDS WILL CHANGE TO RAIN.

BULK OF SNOW ENDS BY 8 OR 9Z TONIGHT AND MUCH OF THE THE REGION
SHOULD ALREADY HAVE VFR CONDITIONS BY 12Z MONDAY.

KBOS TAF...CONFIDENT IN OVERALL TRENDS BUT EXACT TIMING IS MORE
UNCERTAIN.  WHILE SOME LIGHT SNOW IS POSSIBLE THIS
AFTERNOON...BULK OF ACCUMULATING SNOW WITH WIDESPREAD IFR TO LIFR
CONDITIONS EXPECTED THIS EVENING.

KBDL TAF...CONFIDENT IN OVERALL TRENDS BUT EXACT TIMING IS MORE
UNCERTAIN.  WHILE SOME LIGHT SNOW IS POSSIBLE LATE THIS MORNING AND
AFTERNOON...BULK OF ACCUMULATING SNOW WITH WIDESPREAD IFR TO LIFR
CONDITIONS EXPECTED AFTER 3 OR 4 PM.

OUTLOOK...MONDAY THROUGH THURSDAY...

MONDAY... HIGH CONFIDENCE. SOME IFR/MVFR IN SNOW EARLY MORNING BUT
OTHERWISE CONDITIONS WILL IMPROVE TO VFR DURING THE MORNING.
NORTHWEST WINDS WILL INCREASE WITH GUSTS AROUND 30 KNOTS BY MIDDAY.
VFR AND DIMINISHING WIND MONDAY NIGHT.

TUESDAY...MODERATE CONFIDENCE. VFR DURING THE DAY WITH INCREASING
SKY COVER. MVFR TUESDAY EVENING BECOMING IFR/LIFR OVERNIGHT IN
DEVELOPING SNOW AND FREEZING RAIN.

WEDNESDAY...MODERATE CONFIDENCE. IFR/LIFR IN RAIN AND FREEZING RAIN.

THURSDAY...LOW CONFIDENCE. VFR NORTH OF A HFD-BOS LINE. MVFR CIGS
AND AREAS OF MVFR/IFR VSBYS IN SNOW.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /THROUGH MONDAY MORNING/...HIGH CONFIDENCE.

HIGH PRESSURE NEARBY WILL KEEP WINDS/SEAS WELL BELOW SMALL CRAFT
ADVISORY THRESHOLDS INTO SUNDAY MORNING. A WEAK WAVE OF LOW
PRESSURE MOVES ACROSS THE WATERS LATE SUNDAY INTO SUNDAY NIGHT...
BUT WEAK PRESSURE GRADIENT SHOULD KEEP WINDS/SEAS BELOW SMALL
CRAFT THRESHOLDS.

OUTLOOK...MONDAY THROUGH THURSDAY..MODERATE CONFIDENCE.

MONDAY...WEST TO NORTHWEST WINDS INCREASE WITH FREQUENT GUSTS TO
GALE FORCE ESPECIALLY AWAY FROM THE NEARSHORE. THIS COULD GENERATE
SOME LIGHT FREEZING SPRAY ESPECIALLY EARLY MONDAY NIGHT. SEAS 5
TO 10 FEET. WINDS AND SEAS DIMINISH MONDAY NIGHT. A GALE WARNING
MAY BE NEEDED.

TUESDAY... LINGERING 5 FOOT SEAS ON THE OUTER WATERS BUT DIMINISHING
DURING THE MORNING.  WINDS AND SEAS INCREASE AGAIN TUESDAY NIGHT
AFTER MIDNIGHT AHEAD OF A GREAT LAKES COLD FRONT. SOUTH WINDS WILL
APPROACH 25 KNOTS WITH SEAS BUILDING TO 5 TO 8 FEET. VSBYS WILL
BE REDUCED IN SNOW CHANGING TO RAIN.

WEDNESDAY...SOUTHWEST WINDS WITH GUSTS 25-30 KNOTS.  SEAS BUILDING
TO 6 TO 12 FEET. REDUCED VSBYS IN RAIN. A SMALL CRAFT ADVISORY MAY
BE NEEDED.

THURSDAY...NORTHWEST WINDS WILL GUST TO 25 KNOTS...AND SEAS 5 TO 8
FEET. BOTH SHOULD DIMINISH TOWARD EVENING.  A SMALL CRAFT ADVISORY
MAY BE NEEDED.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WINTER STORM WATCH FROM NOON EST TODAY THROUGH MONDAY MORNING
     FOR CTZ002>004.
MA...WINTER WEATHER ADVISORY FROM NOON TODAY TO 7 AM EST MONDAY FOR
     MAZ002>008-010-014-023-024-026.
     WINTER STORM WATCH FROM NOON EST TODAY THROUGH MONDAY MORNING
     FOR MAZ009-011>013-015>022.
RI...WINTER WEATHER ADVISORY FROM NOON TODAY TO 7 AM EST MONDAY FOR
     RIZ008.
     WINTER STORM WATCH FROM NOON EST TODAY THROUGH MONDAY MORNING
     FOR RIZ001>007.
MARINE...NONE.

&&

$$
SYNOPSIS...WTB/SIPPRELL
NEAR TERM...FRANK
SHORT TERM...SIPPRELL
LONG TERM...WTB
AVIATION...FRANK/WTB
MARINE...WTB/SIPPRELL



000
FXUS61 KBOX 010617
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
115 AM EST SUN MAR 1 2015

.SYNOPSIS...

A FAST MOVING LOW PRESSURE SYSTEM WILL BRING ACCUMULATING SNOW TO
THE REGION LATE SUNDAY INTO SUNDAY NIGHT...WITH THE HIGHEST AMOUNTS
EXPECTED SOUTH OF THE MASSACHUSETTS TURNPIKE AND AWAY FROM THE
IMMEDIATE SOUTH COAST. HIGH PRESSURE BRINGS DRY COLD AIR FOR THE
EARLY WEEK. LOW PRESSURE FROM NORTHERN CANADA AND ASSOCIATED LOW
FORMING OVER THE PLAINS MONDAY WILL MERGE...THEN PASS WEST AND
NORTH OF NEW ENGLAND. THIS WILL SWING A COLD FRONT ACROSS THE
REGION ON WEDNESDAY. DRY AND COLD WEATHER RETURNS FOR THE END OF
THE WEEK.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...

115 AM UPDATE...

CLEAR SKIES...LIGHT WINDS AND DEEP SNOW PACK WAS RESULTING IN
ANOTHER EXCELLENT NIGHT OF RADIATIONAL COOLING.  TEMPS ALREADY BELOW
ZERO IN SOME OF THE NORMALLY COLDEST OUTLYING LOCATIONS...WHILE THE
URBAN HEAT ISLAND OF BOSTON STILL HAD TEMPS IN THE LOWER 20S!

LOW TEMPS WILL BOTTOM OUT NEAR 10 BELOW ZERO ACROSS THE
NORMALLY COLDEST OUTLYING LOCATIONS.  OTHER AREAS THAT DO NOT
RADIATE AS WELL SUCH AS THE HIGHER TERRAIN/URBAN CENTERS WILL SEE
LOWS MAINLY IN THE SINGLE DIGITS...TO LOWER TEENS.

THESE LOW TEMPS WILL LIKELY OCCUR BY 4 OR 5 AM AND THEN LEVEL OFF OR
RISE BY DAYBREAK...AS SOME MID/HIGH LEVEL CLOUDINESS MOVES IN FROM
THE WEST.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM MONDAY/...
*/ SUNDAY MORNING INTO MIDDAY...

QUIET WEATHER. CLOUDS THICKENING AS WINDS INCREASE OUT OF THE S.
WILL SEE TEMPERATURES GRADUALLY MODERATE INTO THE MID- TO UPPER-20S.

*/ SUNDAY AFTERNOON INTO EARLY MONDAY MORNING...

1) HIGHLIGHTS...

 - SNOW SUNDAY AFTERNOON INTO MONDAY MORNING
 - GREATEST INTENSITY SUNDAY EVENING AND OVERNIGHT
 - 6+ INCH SNOWFALLS EXPECTED BUT EXACTLY WHERE REMAINS UNCERTAIN
 - ANNOYINGLY...FORECAST GUIDANCE CONTINUES TO WOBBLE

1) OVERVIEW...

BROAD ISENTROPIC OVER-RUNNING EVENT OF GULF MOISTURE ALONG THE 275-
295K SURFACES AMPLIFIED BY A N-STREAM IMPULSE DURING THE TIMEFRAME
POSSIBLY INVOKING AN AREA OF LOW PRESSURE THAT SKIRTS ALONG THE S-
COAST SUBSEQUENTLY ENHANCING LOW-LEVEL WIND PROFILE. LIGHT-MODERATE
SNOWFALL IS ANTICIPATED WITH LOCALLY HEAVIER AMOUNTS. THE INTENSE
PORTION OF SNOWFALL IS EXPECTED SUNDAY EVENING AND OVERNIGHT ENDING
EARLY MONDAY MORNING.

MODEL PREFERENCE GIVEN TO THE ECMWF/GFS/REGIONAL CANADIAN WHICH WILL
SERVE AS THE CONSENSUS OF GUIDANCE FOR THIS DISCUSSION. THE 28.12Z
NAM WAS CONSIDERED AN OUTLIER WITH ITS AGGRESSIVE-MODE AND SECONDARY
LOW DEVELOPMENT JUST OFFSHORE.

2) PRECIPITATION-TYPE...

EVALUATING THERMAL FIELDS...BLEND OF FORECAST CONSENSUS PUTS THE
-2C H925 ISOTHERM W-E ACROSS S-TIER OF CT/RI AND ACROSS SE MA WITH
THE 0C H85 ISOTHERM JUST S OF LONG-ISLAND AND NANTUCKET COASTLINES.
THE CONSENSUS OF 1000-850 MB CRITICAL THICKNESSES LAYS RIGHT ALONG
THE IMMEDIATE S-COAST OF LONG-ISLAND AND CAPE COD.

AN ALL SNOW-EVENT WHEN CONSIDERING DYNAMIC-COOLING/WETBULBING OF THE
LOW-LEVELS AHEAD OF THE EVENT. THERE IS PERHAPS A CHANCE OF A BRIEF
MIX-OVER TO RAIN/FREEZING RAIN ACROSS THE CAPE AND ISLANDS AS S-FLOW
AT THE SURFACE IS POSSIBLY ABLE TO NUDGE ABOVE-FREEZING TEMPERATURES
N. YET AS WE ARE IN A FROZEN TUNDRA...WITH ANY RAIN IT WOULD LIKELY
FREEZE ON SURFACES WHICH ARE QUITE COLD. THUS FREEZING RAIN PREVAILS
OVER RAIN IN THE FORECAST.

3) SNOWFALL...

FORECAST CONSENSUS OF A 0.3-0.6 N-S PRECIPITATION EVENT WITH A N-S
SNOW-TO-LIQUID RATIO GRADIENT RANGING FROM 15:1 TO 10:1 YIELDS HIGH-
END SNOW ADVISORY CRITERIA WITH SNOWFALL AMOUNTS RANGING ON AVERAGE
AROUND 3-6 INCHES. AREAS OF 6+ INCHES ARE EXPECTED...ESPECIALLY FROM
CENTRAL-CT E INTO SE-MA /INCLUDING THE UPPER-CAPE/. A CHALLENGE AND
A LOT OF UNCERTAINTY WITH RESPECT TO HEADLINES AND DECISION-MAKING.

EVALUATING LOW-LEVEL THERMAL PROFILES TOWARDS SNOW-TO-LIQUID RATIOS
DERIVED VIA A COBB-TECHNIQUE...WITH THE GREATEST LIFT OCCURRING
JUST BENEATH OR WITHIN THE DENDRITIC-GROWTH ZONE BASED ON A
CONSENSUS OF BUFKIT GFS PROFILES...ESPECIALLY IN HEAVIER- PRECIP
AREAS...BELIEVE THE SNOW WILL RANGE SOMEWHERE BETWEEN A WET AND
FLUFFY SNOW. SNOW PROPERTIES FROM FLUFFY TO WET LIKELY SIMILAR TO
THE N-S GRADIENT AS OUTLINED ABOVE.

4) HEADLINES...

HATE A WOBBLING FORECAST WHICH IS TYPICAL WITH SUCH SMALL EVENTS.
UNCERTAINTY DERIVES FROM LOW-LEVEL THERMAL PROFILES AND PRECIP
AMOUNTS. SURELY EXPECTING SNOW...BUT WITH ANY SHIFT N-S OF COLDER
AIR AND/OR PRECIPITATION AMOUNTS RESULTS IN AREAS SHIFTING FROM
ADVISORY TO WARNING...OR VICE VERSA. ENOUGH TO JUST PULL YOUR HAIR
OUT. THEN THERE IS THE TIMING OF THE SYSTEM THAT HAS SPED UP
SLIGHTLY. A SHORTER RESIDENCE TIME OF COURSE WOULD YIELD LESSER
SNOWFALL AMOUNTS. QUITE A CHALLENGING FORECAST RIGHT ON THE CUSP
OF HEADLINE THRESHOLDS.

THE EVENT DOES TAKE PLACE MAINLY FROM SUNDAY EVENING INTO THE EARLY
MORNING HOURS ON MONDAY DURING WHICH TIME THERE IS NOT MUCH TRAFFIC
ON THE ROAD. IS THIS A HIGH IMPACT EVENT THAT WARRANTS WARNINGS? A
QUESTION TO STRUGGLE WITH AS WARNINGS ARE NECESSARY WHEN WE ARE
CONFIDENT IN MEETING OR EXCEEDING 6+ INCH CRITERIA. YET THE QUESTION
IN FRONT OF US IS WHERE WILL THE HIGHER AMOUNTS OF SNOW FOCUS? HAVE
TO MAKE SOME SORT OF CALL...THE NEEDS OF THE MANY OUTWEIGH THE NEEDS
OF THE FEW.

ADVISORIES POSTED WHERE THERE IS HIGH CONFIDENCE OF SNOW BUT LIKELY
TO REMAIN BELOW THE 6-INCH THRESHOLD FOR WARNING. WATCHES CONTINUE
AND HAVE BEEN EXTENDED TO THE S-COAST TO COVER FOR THE UNCERTAINTY
OF THE AREA EITHER FALLING WITHIN OR IN EXCESS OF ADVISORY-LEVEL
SNOWS. AGAIN...6+ INCH AMOUNTS ARE ANTICIPATED BUT EXACTLY WHERE IS
UNCERTAIN.

5) CLOSING NOTES...

SOME CONCERN FOR THE EARLY MONDAY MORNING COMMUTE FOR E/SE MA AND
RI. WHILE MOST OF THE SNOW IS EXPECTED TO BE IMMEDIATELY OFFSHORE
WITH SUNRISE MONDAY...COMMUTERS COULD ENCOUNTER SLICK AND SLIPPERY
ROAD CONDITIONS. SNOW COULD POSSIBLY LINGER OVER SE MA SO THERE IS
THE POTENTIAL FOR REDUCED VISIBILITIES.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
BIG PICTURE... THE BROAD UPPER FLOW SHOWS A RIDGE IN THE EAST AND
TROUGH IN THE WEST WITH A WEST SOUTHWEST FLOW FROM THE PLAINS TO THE
EASTERN USA COAST. WITHIN THIS FLOW ARE BOTH NORTHERN AND SOUTHERN
STREAMS AT THE START OF THE WEEK. THE WESTERN TROUGH MIGRATES EAST
DURING THE MIDWEEK AT WHICH TIME THE TWO STREAMS MERGE TO FORM A 140-
160 KT UPPER JET FEEDING NORTHEAST INTO THE GREAT LAKES AND ST
LAWRENCE VALLEY. THIS JET LINGERS OVER OR NEAR NEW ENGLAND THURSDAY-
FRIDAY BEFORE MOVING OFF. THE WESTERN TROUGH MOVES ACROSS NEW
ENGLAND BY THE END OF THE WEEK.

DAILIES...

MONDAY... SUNDAY STORM MOVES OFF PAST NOVA SCOTIA WHILE THE
SUPPORTING UPPER SHORTWAVE AND COLD POOL SWING ACROSS NEW ENGLAND.
THE COOLEST AIR ALOFT IS IN NORTHERN NEW ENGLAND WHILE LEFTOVER
MOISTURE LINGERS BELOW 800 MB THROUGH THE DAY. THE GFS IS FASTER
THAN THE ECMWF IN BRINGING RISING PRESSURE TO THE REGION BUT HAVE 1
MB/HOUR RISES HERE BY EVENING. PUT TOGETHER...EXPECT A CLEARING
TREND BUT WITH LEFTOVER CLOUDS ESPECIALLY NORTH OF THE MASS PIKE.
SUSTAINED NORTHWEST WINDS SHOULD RISE TO 15-20 KTS. MIXING REACHES
TO AT LEAST 850 MB AND POSSIBLY A LITTLE HIGHER...WHICH SUPPORTS
GUSTS TO AT LEAST 30 KNOTS AND POSSIBLY 35 KNOTS. TEMPS AT 850 MB
WILL BE -11C TO -14C...MIXING THIS TO THE SURFACE WOULD SUPPORT MAX
SFC TEMPS IN THE 30S. MIN TEMPERATURES UPSTREAM THIS MORNING WERE IN
THE SINGLE NUMBERS WITH A FEW SPOTS BELOW ZERO. WITH LIGHT PRESSURE
GRADIENT ESP IN THE WEST...WE TENDED A FEW DEGREES COOLER THAN
CONSENSUS.

TUESDAY-WEDNESDAY... HIGH PRESSURE IN CONTROL MUCH OF TUESDAY BUT
MOVING OFFSHORE DURING THE AFTERNOON. CROSS SECTIONS SHOW INCREASING
MOISTURE AT MID AND HIGH CLOUD LEVEL...SO INCREASING HIGH CLOUDS.
SYSTEM MOVING INTO THE GREAT LAKES SPREADS PCPN INTO NEW YORK...BUT
WARM ADVECTION LIFT REMAINS MOSTLY TO OUR WEST THROUGH THE
AFTERNOON. SOME LIFT FORECAST AT 290K /ABOUT 730 MB AT THE TIME/ BUT
NONE BELOW THAT. MEANWHILE DEWPOINTS IN THE SINGLE NUMBERS PROGRESS
INTO THE TEENS DURING THE DAY...BUT ENOUGH OF A TEMP/DEWPOINT SPREAD
TO SLOW THE ADVANCE OF ANY PCPN FROM THE CLOUDS BY A FEW HOURS.

WARM ADVECTION LIFT MUCH OF THE NIGHT SUPPORTS THE IDEA OF PCPN.
TEMPERATURES START COLD DURING THE EVENING BUT SHOULD RISE
OVERNIGHT. THE QUESTION REMAINS AS TO HOW HIGH THEY WILL CLIMB. EVEN
WITH THE SURFACE SYSTEM TRACKING UP THE ST LAWRENCE VALLEY THERE IS
COLD GROUND AND A COLD SNOWPACK. THIS WOULD ALLOW THE WARMER TEMPS
TO SCREAM OVERHEAD WHILE THE IMMEDIATE SURFACE REMAINS SEVERAL
DEGREES COLDER. WE TRIMMED TEMPS BACK A LITTLE FROM MODEL
VALUES...BUT LOW CONFIDENCE AT THIS TIME DUE TO THE POTENTIAL THAT
SURFACE TEMPS COULD REMAIN IN THE 30S.

QPF FORECASTS RANGE FROM 0.50 TO 1.00 INCHES WITH THE HIGHER AMOUNTS
TENDING TOWARD THE SOUTH COAST. THIS POINTS TO A MESSY STORM WITH
INITIAL SNOW ACCUMS OF SEVERAL INCHES FOLLOWED BY A CHANGE TO
MEASURABLE ICE ACCUMULATION AND THEN A CHANGE TO RAIN WITH
POTENTIAL FOR POOR DRAINAGE FLOODING IN BETWEEN THE SNOW BANKS.

THE COLD FRONT SHOULD MOVE THROUGH DURING THE AFTERNOON/EVENING WITH
A SHIFT TO NORTHWEST WINDS. THIS WILL CHANGE THE PCPN BACK TO SNOW
BEFORE TAPERING OFF.

THURSDAY...DIFFERENCES IN THE GFS AND ECMWF IN HANDING THE UPPER JET.
THE ECMWF MOVES THE JET OFFSHORE AND PUTS SOUTHERN NEW ENGLAND
INTO SUBSIDENCE. THE GFS MAINTAINS THE JET OVERHEAD WITH OUR AREA
IN THE RIGHT ENTRANCE REGION. THE FIRST SCENARIO ENDS THE PCPN AND
COOLS THE AIR. THE SECOND SCENARIO WOULD SUPPORT LIFT AND GENERATE
WAVES ALONG THE DEPARTING COLD FRONT...MAINTAINING A CHANCE OF
SNOW OVER AT LEAST SOUTHERN PARTS OF OUR AREA. OUR THURSDAY
FORECAST TENDS TOWARD THE LATTER FOR NOW.

FRIDAY-SATURDAY... HIGH PRESSURE BUILDS OVER THE REGION THURSDAY
NIGHT AND FRIDAY WITH CLEARING SKIES AND A BRIEF PERIOD OF COLD AIR.
TEMPS ALOFT TREND UP ABOUT 10C ON SATURDAY SUGGESTING LESS CHILL AT
THE SURFACE. ANOTHER COLD FRONT APPROACHES THE ST LAWRENCE VALLEY
AND COULD SPREAD SOME CLOUDS INTO OUR AREA SATURDAY
AFTERNOON/EVENING. BUT PCPN CHANCES LOOK SMALL.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TODAY AND TONIGHT/...

TODAY AND TONIGHT...MODERATE CONFIDENCE.  VFR CONDITIONS THROUGH AT
LEAST MID MORNING.  SOME MVFR TO IFR CONDITIONS DEVELOP FROM WEST TO
EAST LATE THIS MORNING AND THIS AFTERNOON IN AREAS OF LIGHT SNOW.
HOWEVER...THE BULK OF THE MODERATE TO EVEN BRIEFLY HEAVY SNOW WILL
OCCUR THIS EVENING WHEN WIDESPREAD IFR TO LIFR CONDITIONS OCCUR.
THE LOWER CONDITIONS MOST LIKELY SOUTH OF THE MA TURNPIKE.  PTYPE
PRETTY MUCH ALL SNOW...EXCEPT FOR THE VERY IMMEDIATE SOUTH
COAST/CAPE WHERE SNOW MAY MIX WITH OR CHANGE TO RAIN FOR A TIME.
WHETHER OR NOT THAT HAPPENS IS UNCERTAIN...BUT WE DO THINK THAT AT
LEAST THE ISLANDS WILL CHANGE TO RAIN.

BULK OF SNOW ENDS BY 8 OR 9Z TONIGHT AND MUCH OF THE THE REGION
SHOULD ALREADY HAVE VFR CONDITIONS BY 12Z MONDAY.

KBOS TAF...CONFIDENT IN OVERALL TRENDS BUT EXACT TIMING IS MORE
UNCERTAIN.  WHILE SOME LIGHT SNOW IS POSSIBLE THIS
AFTERNOON...BULK OF ACCUMULATING SNOW WITH WIDESPREAD IFR TO LIFR
CONDITIONS EXPECTED THIS EVENING.

KBDL TAF...CONFIDENT IN OVERALL TRENDS BUT EXACT TIMING IS MORE
UNCERTAIN.  WHILE SOME LIGHT SNOW IS POSSIBLE LATE THIS MORNING AND
AFTERNOON...BULK OF ACCUMULATING SNOW WITH WIDESPREAD IFR TO LIFR
CONDITIONS EXPECTED AFTER 3 OR 4 PM.

OUTLOOK...MONDAY THROUGH THURSDAY...

MONDAY... HIGH CONFIDENCE. SOME IFR/MVFR IN SNOW EARLY MORNING BUT
OTHERWISE CONDITIONS WILL IMPROVE TO VFR DURING THE MORNING.
NORTHWEST WINDS WILL INCREASE WITH GUSTS AROUND 30 KNOTS BY MIDDAY.
VFR AND DIMINISHING WIND MONDAY NIGHT.

TUESDAY...MODERATE CONFIDENCE. VFR DURING THE DAY WITH INCREASING
SKY COVER. MVFR TUESDAY EVENING BECOMING IFR/LIFR OVERNIGHT IN
DEVELOPING SNOW AND FREEZING RAIN.

WEDNESDAY...MODERATE CONFIDENCE. IFR/LIFR IN RAIN AND FREEZING RAIN.

THURSDAY...LOW CONFIDENCE. VFR NORTH OF A HFD-BOS LINE. MVFR CIGS
AND AREAS OF MVFR/IFR VSBYS IN SNOW.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /THROUGH MONDAY MORNING/...HIGH CONFIDENCE.

HIGH PRESSURE NEARBY WILL KEEP WINDS/SEAS WELL BELOW SMALL CRAFT
ADVISORY THRESHOLDS INTO SUNDAY MORNING. A WEAK WAVE OF LOW
PRESSURE MOVES ACROSS THE WATERS LATE SUNDAY INTO SUNDAY NIGHT...
BUT WEAK PRESSURE GRADIENT SHOULD KEEP WINDS/SEAS BELOW SMALL
CRAFT THRESHOLDS.

OUTLOOK...MONDAY THROUGH THURSDAY..MODERATE CONFIDENCE.

MONDAY...WEST TO NORTHWEST WINDS INCREASE WITH FREQUENT GUSTS TO
GALE FORCE ESPECIALLY AWAY FROM THE NEARSHORE. THIS COULD GENERATE
SOME LIGHT FREEZING SPRAY ESPECIALLY EARLY MONDAY NIGHT. SEAS 5
TO 10 FEET. WINDS AND SEAS DIMINISH MONDAY NIGHT. A GALE WARNING
MAY BE NEEDED.

TUESDAY... LINGERING 5 FOOT SEAS ON THE OUTER WATERS BUT DIMINISHING
DURING THE MORNING.  WINDS AND SEAS INCREASE AGAIN TUESDAY NIGHT
AFTER MIDNIGHT AHEAD OF A GREAT LAKES COLD FRONT. SOUTH WINDS WILL
APPROACH 25 KNOTS WITH SEAS BUILDING TO 5 TO 8 FEET. VSBYS WILL
BE REDUCED IN SNOW CHANGING TO RAIN.

WEDNESDAY...SOUTHWEST WINDS WITH GUSTS 25-30 KNOTS.  SEAS BUILDING
TO 6 TO 12 FEET. REDUCED VSBYS IN RAIN. A SMALL CRAFT ADVISORY MAY
BE NEEDED.

THURSDAY...NORTHWEST WINDS WILL GUST TO 25 KNOTS...AND SEAS 5 TO 8
FEET. BOTH SHOULD DIMINISH TOWARD EVENING.  A SMALL CRAFT ADVISORY
MAY BE NEEDED.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WINTER STORM WATCH FROM NOON EST TODAY THROUGH MONDAY MORNING
     FOR CTZ002>004.
MA...WINTER WEATHER ADVISORY FROM NOON TODAY TO 7 AM EST MONDAY FOR
     MAZ002>008-010-014-023-024-026.
     WINTER STORM WATCH FROM NOON EST TODAY THROUGH MONDAY MORNING
     FOR MAZ009-011>013-015>022.
RI...WINTER WEATHER ADVISORY FROM NOON TODAY TO 7 AM EST MONDAY FOR
     RIZ008.
     WINTER STORM WATCH FROM NOON EST TODAY THROUGH MONDAY MORNING
     FOR RIZ001>007.
MARINE...NONE.

&&

$$
SYNOPSIS...WTB/SIPPRELL
NEAR TERM...FRANK
SHORT TERM...SIPPRELL
LONG TERM...WTB
AVIATION...FRANK/WTB
MARINE...WTB/SIPPRELL




000
FXUS61 KGYX 010346
AFDGYX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
1046 PM EST SAT FEB 28 2015

.SYNOPSIS...
HIGH PRESSURE WILL CREST OVER THE REGION THIS EVENING BEFORE
SHIFTING OFFSHORE SUNDAY. WEAK LOW PRESSURE CROSSES THE REGION
SUNDAY NIGHT...PRODUCING SOME ACCUMULATING SNOW...BEFORE MOVING
INTO THE CANADIAN MARITIMES ON MONDAY. HIGH PRESSURE CROSSES THE
AREA MONDAY NIGHT AND TUESDAY. LOW PRESSURE WILL MOVE OUT OF THE
GREAT LAKES TUESDAY NIGHT AND WILL TRACK NORTHEAST THROUGH THE ST
LAWRENCE VALLEY ON WEDNESDAY...BRINGING A ROUND OF MIXED
PRECIPITATION TO THE AREA. A COLD FRONT FOLLOWS WEDNESDAY NIGHT.
HIGH PRESSURE BUILDS IN FOR THE END OF THE WEEK.

&&

.NEAR TERM /TONIGHT/...
1045PM UPDATE...
HAVE MADE ONE MORE UPDATE FOR OVERNIGHT TEMPERATURES BASED ON
RECENT OBSERVATIONS. NORTHERN VALLEYS ARE ALREADY WELL BELOW ZERO
AND ARE NOW FORECAST TO FALL TO NEAR 20 BELOW TONIGHT. OTHER COLD
SPOTS OUTSIDE OF THE NORTH INCLUDE LEBANON... JAFFREY...
WISCASSET... AND SANFORD. THESE HAVE ALSO FALLEN TO AROUND ZERO
ALREADY AND HOURLY TEMPERATURE TRENDS HAVE BEEN UPDATED TO REFLECT
COLDER TEMPERATURES. OTHERWISE NO SIGNIFICANT CHANGES WERE MADE
TO THE FORECAST.

730PM UPDATE...
HAVE UPDATED OVERNIGHT TEMPERATURE FORECAST TO LOWER FORECAST
VALUES BY A FEW DEGREES PRIMARILY IN KNOWN COLD SPOTS AND ACROSS
SOUTHWEST NEW HAMPSHIRE. ALTHOUGH WINDS ARE MORE CALM TONIGHT THAN
LAST NIGHT... THERE ARE A FEW FACTORS WHICH GIVE REASON TO BELIEVE
WE WILL GENERALLY NOT FALL AS LOW TONIGHT AS LAST NIGHT. THE FIRST
IS THAT DEWPOINT VALUES ARE 5 TO 10 DEGREES WARMER THIS EVENING
THAN YESTERDAY EVENING... THOUGH ADMITTEDLY THESE ARE STILL
GENERALLY AROUND OR BELOW ZERO. AT THIS LEVEL OF DRYNESS IT DOES
NOT TAKE MUCH TO DIG BENEATH CURRENT DEWPOINTS ONCE COOLING
MAXIMIZES ESPECIALLY IN LOCAL VALLEYS. ANOTHER FACTOR IS AFTERNOON
TEMPERATURES STARTED OFF WARMER TODAY... MEANING TEMPERATURES HAVE
FURTHER TO FALL TONIGHT TO REACH THE SAME LEVELS. ONE FINAL FACTOR
IS THE EXPECTED EVENTUAL ARRIVAL OF SOME CIRRUS CLOUDS IN ADVANCE
OF THE APPROACHING SYSTEM BY MORNING. THIS COULD LIMIT COOLING
JUST BEFORE DAWN BY JUST A BIT. EVEN WITH ALL THESE LIMITATIONS...
STILL EXPECT A GOOD CHUNK OF THE AREA TO FALL BELOW ZERO AGAIN.
SHOULD MAKE A DECENT RUN AT ZERO IN PORTLAND AS WELL.

PRECIPITATION CHANCES WERE UPDATED AS WELL TO FURTHER CLARIFY WHEN
PRECIPITATION SHOULD BEGIN AND END ACROSS THE AREA NOT JUST
TONIGHT (NO PRECIPITATION TONIGHT) BUT ALSO TOMORROW AND SUNDAY
NIGHT WHEN CONFIDENCE IS HIGH THAT COASTAL AREAS WILL SEE SOME
MINOR ACCUMULATIONS.

ORIGINAL DISCUSSION...
THE COLDEST MONTH EVER FOR PORTLAND MAINE WILL BE IN THE BOOKS
SHORTLY. LAST NIGHT WAS NEAR RECORD COLD AS WELL...WITH A LOW OF
MINUS 7 IN THE FOREST CITY. THIS IS JUST SHY OF THE RECORD LOW OF
MINUS 9 SET BACK IN 1950.

WITH CLEAR SKIES AND LIGHT WINDS...EXPECT RADIATIONAL COOLING ONCE
AGAIN TONIGHT. WILL FORECAST ON THE LOWER END OF THE 12Z MODEL
SUITE WITH READINGS APPROACHING ZERO NEAR THE COASTLINE AND BELOW
ZERO OVER INTERIOR LOCATIONS. HIGH CLOUDS WILL BE ARRIVING LATER
TONIGHT. THIS MAY KEEP READINGS FROM TRULY BOTTOMING OUT AS WAS
THE CASE LAST NIGHT.

&&

.SHORT TERM /SUNDAY AND SUNDAY NIGHT/...
A BROAD AND WEAK AREA OF WARM AIR ADVECTION WILL ALLOW CLOUDS TO
THICKEN ON SUNDAY ACROSS THE FORECAST AREA. LIGHT SNOW WILL BREAK
OUT SUNDAY NIGHT AS THIS DEVELOPING MOISTURE INTERACTS WITH AN
APPROACHING UPPER LEVEL TROUGH.

SURFACE LOW PRESSURE WILL FORM IN THE GULF OF MAINE LATE SUNDAY
NIGHT...BUT LIKELY TOO LATE TO BRING APPRECIABLE MOISTURE AND
SNOWFALL TO THE REGION. NEVERTHELESS...THERE WILL BE TWO TO AS
MUCH AS FOUR INCHES OF SNOW OVER SOUTHERNMOST PORTIONS OF THE
FORECAST AREA. FURTHER TO THE NORTH...AS HAS BEEN THE CASE MUCH OF
THIS WINTER...LESS SNOW WILL FALL.

TEMPERATURES WILL BE MODERATING BUT STILL BELOW NORMAL FOR THIS
TIME OF THE YEAR.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
A SURFACE LOW EXITS RAPIDLY EAST INTO THE MARITIMES MONDAY WHILE
THE UPPER TROF MOVES THROUGH NORTHERN NEW ENGLAND. THE
PRECIPITATION WILL QUICKLY COME TO AN END EARLY MONDAY AS
DOWNSLOPING NORTHWEST WINDS KICK IN. HIGH PRESSURE BUILDS INTO THE
AREA MONDAY NIGHT AND TUESDAY. A FAST MOVING SHORT WAVE WITH
ASSOCIATED WARM AIR ADVECTION OVERRUNNING PRECIPITATION WILL MOVE
INTO THE AREA TUESDAY NIGHT IN THE FORM OF SNOW. SEVERAL INCHES OF
SNOW IS EXPECTED THROUGHOUT THE AREA. BY WEDNESDAY MORNING A BRIEF
CHANGEOVER TO A MIX OF RAIN OR SNOW SHOWERS OVER SOUTHERN AREAS IS
POSSIBLE BEFORE THE PRECIPITATION ENDS AS LOW AND MID LEVEL
TEMPERATURES MAY WARM ABOVE CRITICAL LEVELS. BY LATE WEDNESDAY
MORNING A COLD FRONT MOVES ACROSS THE AREA AND THEN OFFSHORE WITH
CLEARING BEHIND THE FRONT. HIGH PRESSURE BUILDS INTO THE REGION
FOR THURSDAY AND FRIDAY WITH FAIR CONDITIONS.

TEMPERATURES WILL GENERALLY REMAIN BELOW NORMAL FOR THE WEEK. USED
A BLEND OF THE MODELS FOR TEMPERATURES AND POPS.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
SHORT TERM...VFR CONDITIONS DETERIORATING TO MVFR AND IFR SUNDAY
NIGHT IN LIGHT SNOW.

LONG TERM...
MVFR TO IFR CONDITIONS EARLY MONDAY WILL IMPROVE TO VFR BY LATE
MORNING MONDAY AND CONTINUE THROUGH TUESDAY. TUESDAY NIGHT MVFR TO
IFR CONDITIONS WILL DEVELOP AND CONTINUE INTO WEDNESDAY MORNING.
CONDITIONS WILL RETURN TO VFR BY WEDNESDAY AFTERNOON AND CONTINUE
THROUGH FRIDAY.

&&

.MARINE...
SHORT TERM...NO FLAGS. WINDS BELOW SCA THRESHOLDS AS WELL AS SEAS
IN THE SHORT TERM PORTION OF THE FORECAST.

LONG TERM...EXPECT TO NEED A STRONG SCA MONDAY AFTERNOON INTO
MONDAY NIGHT IN AN INCREASING WEST FLOW...WINDS DIMINISH LATE
MONDAY NIGHT. SCA MAY BE NEEDED AGAIN IN A SOUTH TO SOUTHWEST
FLOW LATE TUESDAY NIGHT AND WEDNESDAY.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.

&&

$$

NEAR TERM UPDATE...KIMBLE
SHORT TERM...CANNON
LONG TERM...MARINE
AVIATION...CANNON/MARINE
MARINE...CANNON/MARINE




000
FXUS61 KGYX 010346
AFDGYX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
1046 PM EST SAT FEB 28 2015

.SYNOPSIS...
HIGH PRESSURE WILL CREST OVER THE REGION THIS EVENING BEFORE
SHIFTING OFFSHORE SUNDAY. WEAK LOW PRESSURE CROSSES THE REGION
SUNDAY NIGHT...PRODUCING SOME ACCUMULATING SNOW...BEFORE MOVING
INTO THE CANADIAN MARITIMES ON MONDAY. HIGH PRESSURE CROSSES THE
AREA MONDAY NIGHT AND TUESDAY. LOW PRESSURE WILL MOVE OUT OF THE
GREAT LAKES TUESDAY NIGHT AND WILL TRACK NORTHEAST THROUGH THE ST
LAWRENCE VALLEY ON WEDNESDAY...BRINGING A ROUND OF MIXED
PRECIPITATION TO THE AREA. A COLD FRONT FOLLOWS WEDNESDAY NIGHT.
HIGH PRESSURE BUILDS IN FOR THE END OF THE WEEK.

&&

.NEAR TERM /TONIGHT/...
1045PM UPDATE...
HAVE MADE ONE MORE UPDATE FOR OVERNIGHT TEMPERATURES BASED ON
RECENT OBSERVATIONS. NORTHERN VALLEYS ARE ALREADY WELL BELOW ZERO
AND ARE NOW FORECAST TO FALL TO NEAR 20 BELOW TONIGHT. OTHER COLD
SPOTS OUTSIDE OF THE NORTH INCLUDE LEBANON... JAFFREY...
WISCASSET... AND SANFORD. THESE HAVE ALSO FALLEN TO AROUND ZERO
ALREADY AND HOURLY TEMPERATURE TRENDS HAVE BEEN UPDATED TO REFLECT
COLDER TEMPERATURES. OTHERWISE NO SIGNIFICANT CHANGES WERE MADE
TO THE FORECAST.

730PM UPDATE...
HAVE UPDATED OVERNIGHT TEMPERATURE FORECAST TO LOWER FORECAST
VALUES BY A FEW DEGREES PRIMARILY IN KNOWN COLD SPOTS AND ACROSS
SOUTHWEST NEW HAMPSHIRE. ALTHOUGH WINDS ARE MORE CALM TONIGHT THAN
LAST NIGHT... THERE ARE A FEW FACTORS WHICH GIVE REASON TO BELIEVE
WE WILL GENERALLY NOT FALL AS LOW TONIGHT AS LAST NIGHT. THE FIRST
IS THAT DEWPOINT VALUES ARE 5 TO 10 DEGREES WARMER THIS EVENING
THAN YESTERDAY EVENING... THOUGH ADMITTEDLY THESE ARE STILL
GENERALLY AROUND OR BELOW ZERO. AT THIS LEVEL OF DRYNESS IT DOES
NOT TAKE MUCH TO DIG BENEATH CURRENT DEWPOINTS ONCE COOLING
MAXIMIZES ESPECIALLY IN LOCAL VALLEYS. ANOTHER FACTOR IS AFTERNOON
TEMPERATURES STARTED OFF WARMER TODAY... MEANING TEMPERATURES HAVE
FURTHER TO FALL TONIGHT TO REACH THE SAME LEVELS. ONE FINAL FACTOR
IS THE EXPECTED EVENTUAL ARRIVAL OF SOME CIRRUS CLOUDS IN ADVANCE
OF THE APPROACHING SYSTEM BY MORNING. THIS COULD LIMIT COOLING
JUST BEFORE DAWN BY JUST A BIT. EVEN WITH ALL THESE LIMITATIONS...
STILL EXPECT A GOOD CHUNK OF THE AREA TO FALL BELOW ZERO AGAIN.
SHOULD MAKE A DECENT RUN AT ZERO IN PORTLAND AS WELL.

PRECIPITATION CHANCES WERE UPDATED AS WELL TO FURTHER CLARIFY WHEN
PRECIPITATION SHOULD BEGIN AND END ACROSS THE AREA NOT JUST
TONIGHT (NO PRECIPITATION TONIGHT) BUT ALSO TOMORROW AND SUNDAY
NIGHT WHEN CONFIDENCE IS HIGH THAT COASTAL AREAS WILL SEE SOME
MINOR ACCUMULATIONS.

ORIGINAL DISCUSSION...
THE COLDEST MONTH EVER FOR PORTLAND MAINE WILL BE IN THE BOOKS
SHORTLY. LAST NIGHT WAS NEAR RECORD COLD AS WELL...WITH A LOW OF
MINUS 7 IN THE FOREST CITY. THIS IS JUST SHY OF THE RECORD LOW OF
MINUS 9 SET BACK IN 1950.

WITH CLEAR SKIES AND LIGHT WINDS...EXPECT RADIATIONAL COOLING ONCE
AGAIN TONIGHT. WILL FORECAST ON THE LOWER END OF THE 12Z MODEL
SUITE WITH READINGS APPROACHING ZERO NEAR THE COASTLINE AND BELOW
ZERO OVER INTERIOR LOCATIONS. HIGH CLOUDS WILL BE ARRIVING LATER
TONIGHT. THIS MAY KEEP READINGS FROM TRULY BOTTOMING OUT AS WAS
THE CASE LAST NIGHT.

&&

.SHORT TERM /SUNDAY AND SUNDAY NIGHT/...
A BROAD AND WEAK AREA OF WARM AIR ADVECTION WILL ALLOW CLOUDS TO
THICKEN ON SUNDAY ACROSS THE FORECAST AREA. LIGHT SNOW WILL BREAK
OUT SUNDAY NIGHT AS THIS DEVELOPING MOISTURE INTERACTS WITH AN
APPROACHING UPPER LEVEL TROUGH.

SURFACE LOW PRESSURE WILL FORM IN THE GULF OF MAINE LATE SUNDAY
NIGHT...BUT LIKELY TOO LATE TO BRING APPRECIABLE MOISTURE AND
SNOWFALL TO THE REGION. NEVERTHELESS...THERE WILL BE TWO TO AS
MUCH AS FOUR INCHES OF SNOW OVER SOUTHERNMOST PORTIONS OF THE
FORECAST AREA. FURTHER TO THE NORTH...AS HAS BEEN THE CASE MUCH OF
THIS WINTER...LESS SNOW WILL FALL.

TEMPERATURES WILL BE MODERATING BUT STILL BELOW NORMAL FOR THIS
TIME OF THE YEAR.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
A SURFACE LOW EXITS RAPIDLY EAST INTO THE MARITIMES MONDAY WHILE
THE UPPER TROF MOVES THROUGH NORTHERN NEW ENGLAND. THE
PRECIPITATION WILL QUICKLY COME TO AN END EARLY MONDAY AS
DOWNSLOPING NORTHWEST WINDS KICK IN. HIGH PRESSURE BUILDS INTO THE
AREA MONDAY NIGHT AND TUESDAY. A FAST MOVING SHORT WAVE WITH
ASSOCIATED WARM AIR ADVECTION OVERRUNNING PRECIPITATION WILL MOVE
INTO THE AREA TUESDAY NIGHT IN THE FORM OF SNOW. SEVERAL INCHES OF
SNOW IS EXPECTED THROUGHOUT THE AREA. BY WEDNESDAY MORNING A BRIEF
CHANGEOVER TO A MIX OF RAIN OR SNOW SHOWERS OVER SOUTHERN AREAS IS
POSSIBLE BEFORE THE PRECIPITATION ENDS AS LOW AND MID LEVEL
TEMPERATURES MAY WARM ABOVE CRITICAL LEVELS. BY LATE WEDNESDAY
MORNING A COLD FRONT MOVES ACROSS THE AREA AND THEN OFFSHORE WITH
CLEARING BEHIND THE FRONT. HIGH PRESSURE BUILDS INTO THE REGION
FOR THURSDAY AND FRIDAY WITH FAIR CONDITIONS.

TEMPERATURES WILL GENERALLY REMAIN BELOW NORMAL FOR THE WEEK. USED
A BLEND OF THE MODELS FOR TEMPERATURES AND POPS.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
SHORT TERM...VFR CONDITIONS DETERIORATING TO MVFR AND IFR SUNDAY
NIGHT IN LIGHT SNOW.

LONG TERM...
MVFR TO IFR CONDITIONS EARLY MONDAY WILL IMPROVE TO VFR BY LATE
MORNING MONDAY AND CONTINUE THROUGH TUESDAY. TUESDAY NIGHT MVFR TO
IFR CONDITIONS WILL DEVELOP AND CONTINUE INTO WEDNESDAY MORNING.
CONDITIONS WILL RETURN TO VFR BY WEDNESDAY AFTERNOON AND CONTINUE
THROUGH FRIDAY.

&&

.MARINE...
SHORT TERM...NO FLAGS. WINDS BELOW SCA THRESHOLDS AS WELL AS SEAS
IN THE SHORT TERM PORTION OF THE FORECAST.

LONG TERM...EXPECT TO NEED A STRONG SCA MONDAY AFTERNOON INTO
MONDAY NIGHT IN AN INCREASING WEST FLOW...WINDS DIMINISH LATE
MONDAY NIGHT. SCA MAY BE NEEDED AGAIN IN A SOUTH TO SOUTHWEST
FLOW LATE TUESDAY NIGHT AND WEDNESDAY.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.

&&

$$

NEAR TERM UPDATE...KIMBLE
SHORT TERM...CANNON
LONG TERM...MARINE
AVIATION...CANNON/MARINE
MARINE...CANNON/MARINE



000
FXUS61 KGYX 010346
AFDGYX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
1046 PM EST SAT FEB 28 2015

.SYNOPSIS...
HIGH PRESSURE WILL CREST OVER THE REGION THIS EVENING BEFORE
SHIFTING OFFSHORE SUNDAY. WEAK LOW PRESSURE CROSSES THE REGION
SUNDAY NIGHT...PRODUCING SOME ACCUMULATING SNOW...BEFORE MOVING
INTO THE CANADIAN MARITIMES ON MONDAY. HIGH PRESSURE CROSSES THE
AREA MONDAY NIGHT AND TUESDAY. LOW PRESSURE WILL MOVE OUT OF THE
GREAT LAKES TUESDAY NIGHT AND WILL TRACK NORTHEAST THROUGH THE ST
LAWRENCE VALLEY ON WEDNESDAY...BRINGING A ROUND OF MIXED
PRECIPITATION TO THE AREA. A COLD FRONT FOLLOWS WEDNESDAY NIGHT.
HIGH PRESSURE BUILDS IN FOR THE END OF THE WEEK.

&&

.NEAR TERM /TONIGHT/...
1045PM UPDATE...
HAVE MADE ONE MORE UPDATE FOR OVERNIGHT TEMPERATURES BASED ON
RECENT OBSERVATIONS. NORTHERN VALLEYS ARE ALREADY WELL BELOW ZERO
AND ARE NOW FORECAST TO FALL TO NEAR 20 BELOW TONIGHT. OTHER COLD
SPOTS OUTSIDE OF THE NORTH INCLUDE LEBANON... JAFFREY...
WISCASSET... AND SANFORD. THESE HAVE ALSO FALLEN TO AROUND ZERO
ALREADY AND HOURLY TEMPERATURE TRENDS HAVE BEEN UPDATED TO REFLECT
COLDER TEMPERATURES. OTHERWISE NO SIGNIFICANT CHANGES WERE MADE
TO THE FORECAST.

730PM UPDATE...
HAVE UPDATED OVERNIGHT TEMPERATURE FORECAST TO LOWER FORECAST
VALUES BY A FEW DEGREES PRIMARILY IN KNOWN COLD SPOTS AND ACROSS
SOUTHWEST NEW HAMPSHIRE. ALTHOUGH WINDS ARE MORE CALM TONIGHT THAN
LAST NIGHT... THERE ARE A FEW FACTORS WHICH GIVE REASON TO BELIEVE
WE WILL GENERALLY NOT FALL AS LOW TONIGHT AS LAST NIGHT. THE FIRST
IS THAT DEWPOINT VALUES ARE 5 TO 10 DEGREES WARMER THIS EVENING
THAN YESTERDAY EVENING... THOUGH ADMITTEDLY THESE ARE STILL
GENERALLY AROUND OR BELOW ZERO. AT THIS LEVEL OF DRYNESS IT DOES
NOT TAKE MUCH TO DIG BENEATH CURRENT DEWPOINTS ONCE COOLING
MAXIMIZES ESPECIALLY IN LOCAL VALLEYS. ANOTHER FACTOR IS AFTERNOON
TEMPERATURES STARTED OFF WARMER TODAY... MEANING TEMPERATURES HAVE
FURTHER TO FALL TONIGHT TO REACH THE SAME LEVELS. ONE FINAL FACTOR
IS THE EXPECTED EVENTUAL ARRIVAL OF SOME CIRRUS CLOUDS IN ADVANCE
OF THE APPROACHING SYSTEM BY MORNING. THIS COULD LIMIT COOLING
JUST BEFORE DAWN BY JUST A BIT. EVEN WITH ALL THESE LIMITATIONS...
STILL EXPECT A GOOD CHUNK OF THE AREA TO FALL BELOW ZERO AGAIN.
SHOULD MAKE A DECENT RUN AT ZERO IN PORTLAND AS WELL.

PRECIPITATION CHANCES WERE UPDATED AS WELL TO FURTHER CLARIFY WHEN
PRECIPITATION SHOULD BEGIN AND END ACROSS THE AREA NOT JUST
TONIGHT (NO PRECIPITATION TONIGHT) BUT ALSO TOMORROW AND SUNDAY
NIGHT WHEN CONFIDENCE IS HIGH THAT COASTAL AREAS WILL SEE SOME
MINOR ACCUMULATIONS.

ORIGINAL DISCUSSION...
THE COLDEST MONTH EVER FOR PORTLAND MAINE WILL BE IN THE BOOKS
SHORTLY. LAST NIGHT WAS NEAR RECORD COLD AS WELL...WITH A LOW OF
MINUS 7 IN THE FOREST CITY. THIS IS JUST SHY OF THE RECORD LOW OF
MINUS 9 SET BACK IN 1950.

WITH CLEAR SKIES AND LIGHT WINDS...EXPECT RADIATIONAL COOLING ONCE
AGAIN TONIGHT. WILL FORECAST ON THE LOWER END OF THE 12Z MODEL
SUITE WITH READINGS APPROACHING ZERO NEAR THE COASTLINE AND BELOW
ZERO OVER INTERIOR LOCATIONS. HIGH CLOUDS WILL BE ARRIVING LATER
TONIGHT. THIS MAY KEEP READINGS FROM TRULY BOTTOMING OUT AS WAS
THE CASE LAST NIGHT.

&&

.SHORT TERM /SUNDAY AND SUNDAY NIGHT/...
A BROAD AND WEAK AREA OF WARM AIR ADVECTION WILL ALLOW CLOUDS TO
THICKEN ON SUNDAY ACROSS THE FORECAST AREA. LIGHT SNOW WILL BREAK
OUT SUNDAY NIGHT AS THIS DEVELOPING MOISTURE INTERACTS WITH AN
APPROACHING UPPER LEVEL TROUGH.

SURFACE LOW PRESSURE WILL FORM IN THE GULF OF MAINE LATE SUNDAY
NIGHT...BUT LIKELY TOO LATE TO BRING APPRECIABLE MOISTURE AND
SNOWFALL TO THE REGION. NEVERTHELESS...THERE WILL BE TWO TO AS
MUCH AS FOUR INCHES OF SNOW OVER SOUTHERNMOST PORTIONS OF THE
FORECAST AREA. FURTHER TO THE NORTH...AS HAS BEEN THE CASE MUCH OF
THIS WINTER...LESS SNOW WILL FALL.

TEMPERATURES WILL BE MODERATING BUT STILL BELOW NORMAL FOR THIS
TIME OF THE YEAR.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
A SURFACE LOW EXITS RAPIDLY EAST INTO THE MARITIMES MONDAY WHILE
THE UPPER TROF MOVES THROUGH NORTHERN NEW ENGLAND. THE
PRECIPITATION WILL QUICKLY COME TO AN END EARLY MONDAY AS
DOWNSLOPING NORTHWEST WINDS KICK IN. HIGH PRESSURE BUILDS INTO THE
AREA MONDAY NIGHT AND TUESDAY. A FAST MOVING SHORT WAVE WITH
ASSOCIATED WARM AIR ADVECTION OVERRUNNING PRECIPITATION WILL MOVE
INTO THE AREA TUESDAY NIGHT IN THE FORM OF SNOW. SEVERAL INCHES OF
SNOW IS EXPECTED THROUGHOUT THE AREA. BY WEDNESDAY MORNING A BRIEF
CHANGEOVER TO A MIX OF RAIN OR SNOW SHOWERS OVER SOUTHERN AREAS IS
POSSIBLE BEFORE THE PRECIPITATION ENDS AS LOW AND MID LEVEL
TEMPERATURES MAY WARM ABOVE CRITICAL LEVELS. BY LATE WEDNESDAY
MORNING A COLD FRONT MOVES ACROSS THE AREA AND THEN OFFSHORE WITH
CLEARING BEHIND THE FRONT. HIGH PRESSURE BUILDS INTO THE REGION
FOR THURSDAY AND FRIDAY WITH FAIR CONDITIONS.

TEMPERATURES WILL GENERALLY REMAIN BELOW NORMAL FOR THE WEEK. USED
A BLEND OF THE MODELS FOR TEMPERATURES AND POPS.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
SHORT TERM...VFR CONDITIONS DETERIORATING TO MVFR AND IFR SUNDAY
NIGHT IN LIGHT SNOW.

LONG TERM...
MVFR TO IFR CONDITIONS EARLY MONDAY WILL IMPROVE TO VFR BY LATE
MORNING MONDAY AND CONTINUE THROUGH TUESDAY. TUESDAY NIGHT MVFR TO
IFR CONDITIONS WILL DEVELOP AND CONTINUE INTO WEDNESDAY MORNING.
CONDITIONS WILL RETURN TO VFR BY WEDNESDAY AFTERNOON AND CONTINUE
THROUGH FRIDAY.

&&

.MARINE...
SHORT TERM...NO FLAGS. WINDS BELOW SCA THRESHOLDS AS WELL AS SEAS
IN THE SHORT TERM PORTION OF THE FORECAST.

LONG TERM...EXPECT TO NEED A STRONG SCA MONDAY AFTERNOON INTO
MONDAY NIGHT IN AN INCREASING WEST FLOW...WINDS DIMINISH LATE
MONDAY NIGHT. SCA MAY BE NEEDED AGAIN IN A SOUTH TO SOUTHWEST
FLOW LATE TUESDAY NIGHT AND WEDNESDAY.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.

&&

$$

NEAR TERM UPDATE...KIMBLE
SHORT TERM...CANNON
LONG TERM...MARINE
AVIATION...CANNON/MARINE
MARINE...CANNON/MARINE




000
FXUS61 KBOX 010217
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
917 PM EST SAT FEB 28 2015

.SYNOPSIS...

A FAST MOVING LOW PRESSURE SYSTEM WILL BRING ACCUMULATING SNOW TO
THE REGION LATE SUNDAY INTO SUNDAY NIGHT...WITH THE HIGHEST AMOUNTS
EXPECTED SOUTH OF THE MASSACHUSETTS TURNPIKE AND AWAY FROM THE
IMMEDIATE SOUTH COAST. HIGH PRESSURE BRINGS DRY COLD AIR FOR THE
EARLY WEEK. LOW PRESSURE FROM NORTHERN CANADA AND ASSOCIATED LOW
FORMING OVER THE PLAINS MONDAY WILL MERGE...THEN PASS WEST AND
NORTH OF NEW ENGLAND. THIS WILL SWING A COLD FRONT ACROSS THE
REGION ON WEDNESDAY. DRY AND COLD WEATHER RETURNS FOR THE END OF
THE WEEK.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...

915 PM UPDATE...

CLEAR SKIES...LIGHT WINDS AND DEEP SNOW PACK WERE RESULTING IN
ANOTHER EXCELLENT NIGHT OF RADIATIONAL COOLING THIS EVENING WITH A
WIDE RANGE IN TEMPERATURES.  LOW TEMPS WILL BOTTOM OUT BETWEEN 5 AND
10 BELOW ZERO ACROSS THE NORMALLY COLDEST OUTLYING LOCATIONS.  OTHER
AREAS THAT DO NOT RADIATE AS WELL SUCH AS THE HIGHER TERRAIN/URBAN
CENTERS WILL SEE LOWS MAINLY IN THE SINGLE DIGITS...TO LOWER TEENS.

THESE LOW TEMPS WILL LIKELY OCCUR A FEW HOURS BEFORE SUNRISE AND
THEN LEVEL OFF OR RISE BY DAYBREAK AS SOME MID/HIGH LEVEL CLOUDINESS
MOVES IN FROM THE WEST.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
*/ SUNDAY MORNING INTO MIDDAY...

QUIET WEATHER. CLOUDS THICKENING AS WINDS INCREASE OUT OF THE S.
WILL SEE TEMPERATURES GRADUALLY MODERATE INTO THE MID- TO UPPER-20S.

*/ SUNDAY AFTERNOON INTO EARLY MONDAY MORNING...

1) HIGHLIGHTS...

 - SNOW SUNDAY AFTERNOON INTO MONDAY MORNING
 - GREATEST INTENSITY SUNDAY EVENING AND OVERNIGHT
 - 6+ INCH SNOWFALLS EXPECTED BUT EXACTLY WHERE REMAINS UNCERTAIN
 - ANNOYINGLY...FORECAST GUIDANCE CONTINUES TO WOBBLE

1) OVERVIEW...

BROAD ISENTROPIC OVER-RUNNING EVENT OF GULF MOISTURE ALONG THE 275-
295K SURFACES AMPLIFIED BY A N-STREAM IMPULSE DURING THE TIMEFRAME
POSSIBLY INVOKING AN AREA OF LOW PRESSURE THAT SKIRTS ALONG THE S-
COAST SUBSEQUENTLY ENHANCING LOW-LEVEL WIND PROFILE. LIGHT-MODERATE
SNOWFALL IS ANTICIPATED WITH LOCALLY HEAVIER AMOUNTS. THE INTENSE
PORTION OF SNOWFALL IS EXPECTED SUNDAY EVENING AND OVERNIGHT ENDING
EARLY MONDAY MORNING.

MODEL PREFERENCE GIVEN TO THE ECMWF/GFS/REGIONAL CANADIAN WHICH WILL
SERVE AS THE CONSENSUS OF GUIDANCE FOR THIS DISCUSSION. THE 28.12Z
NAM WAS CONSIDERED AN OUTLIER WITH ITS AGGRESSIVE-MODE AND SECONDARY
LOW DEVELOPMENT JUST OFFSHORE.

2) PRECIPITATION-TYPE...

EVALUATING THERMAL FIELDS...BLEND OF FORECAST CONSENSUS PUTS THE
-2C H925 ISOTHERM W-E ACROSS S-TIER OF CT/RI AND ACROSS SE MA WITH
THE 0C H85 ISOTHERM JUST S OF LONG-ISLAND AND NANTUCKET COASTLINES.
THE CONSENSUS OF 1000-850 MB CRITICAL THICKNESSES LAYS RIGHT ALONG
THE IMMEDIATE S-COAST OF LONG-ISLAND AND CAPE COD.

AN ALL SNOW-EVENT WHEN CONSIDERING DYNAMIC-COOLING/WETBULBING OF THE
LOW-LEVELS AHEAD OF THE EVENT. THERE IS PERHAPS A CHANCE OF A BRIEF
MIX-OVER TO RAIN/FREEZING RAIN ACROSS THE CAPE AND ISLANDS AS S-FLOW
AT THE SURFACE IS POSSIBLY ABLE TO NUDGE ABOVE-FREEZING TEMPERATURES
N. YET AS WE ARE IN A FROZEN TUNDRA...WITH ANY RAIN IT WOULD LIKELY
FREEZE ON SURFACES WHICH ARE QUITE COLD. THUS FREEZING RAIN PREVAILS
OVER RAIN IN THE FORECAST.

3) SNOWFALL...

FORECAST CONSENSUS OF A 0.3-0.6 N-S PRECIPITATION EVENT WITH A N-S
SNOW-TO-LIQUID RATIO GRADIENT RANGING FROM 15:1 TO 10:1 YIELDS HIGH-
END SNOW ADVISORY CRITERIA WITH SNOWFALL AMOUNTS RANGING ON AVERAGE
AROUND 3-6 INCHES. AREAS OF 6+ INCHES ARE EXPECTED...ESPECIALLY FROM
CENTRAL-CT E INTO SE-MA /INCLUDING THE UPPER-CAPE/. A CHALLENGE AND
A LOT OF UNCERTAINTY WITH RESPECT TO HEADLINES AND DECISION-MAKING.

EVALUATING LOW-LEVEL THERMAL PROFILES TOWARDS SNOW-TO-LIQUID RATIOS
DERIVED VIA A COBB-TECHNIQUE...WITH THE GREATEST LIFT OCCURRING
JUST BENEATH OR WITHIN THE DENDRITIC-GROWTH ZONE BASED ON A
CONSENSUS OF BUFKIT GFS PROFILES...ESPECIALLY IN HEAVIER- PRECIP
AREAS...BELIEVE THE SNOW WILL RANGE SOMEWHERE BETWEEN A WET AND
FLUFFY SNOW. SNOW PROPERTIES FROM FLUFFY TO WET LIKELY SIMILAR TO
THE N-S GRADIENT AS OUTLINED ABOVE.

4) HEADLINES...

HATE A WOBBLING FORECAST WHICH IS TYPICAL WITH SUCH SMALL EVENTS.
UNCERTAINTY DERIVES FROM LOW-LEVEL THERMAL PROFILES AND PRECIP
AMOUNTS. SURELY EXPECTING SNOW...BUT WITH ANY SHIFT N-S OF COLDER
AIR AND/OR PRECIPITATION AMOUNTS RESULTS IN AREAS SHIFTING FROM
ADVISORY TO WARNING...OR VICE VERSA. ENOUGH TO JUST PULL YOUR HAIR
OUT. THEN THERE IS THE TIMING OF THE SYSTEM THAT HAS SPED UP
SLIGHTLY. A SHORTER RESIDENCE TIME OF COURSE WOULD YIELD LESSER
SNOWFALL AMOUNTS. QUITE A CHALLENGING FORECAST RIGHT ON THE CUSP
OF HEADLINE THRESHOLDS.

THE EVENT DOES TAKE PLACE MAINLY FROM SUNDAY EVENING INTO THE EARLY
MORNING HOURS ON MONDAY DURING WHICH TIME THERE IS NOT MUCH TRAFFIC
ON THE ROAD. IS THIS A HIGH IMPACT EVENT THAT WARRANTS WARNINGS? A
QUESTION TO STRUGGLE WITH AS WARNINGS ARE NECESSARY WHEN WE ARE
CONFIDENT IN MEETING OR EXCEEDING 6+ INCH CRITERIA. YET THE QUESTION
IN FRONT OF US IS WHERE WILL THE HIGHER AMOUNTS OF SNOW FOCUS? HAVE
TO MAKE SOME SORT OF CALL...THE NEEDS OF THE MANY OUTWEIGH THE NEEDS
OF THE FEW.

ADVISORIES POSTED WHERE THERE IS HIGH CONFIDENCE OF SNOW BUT LIKELY
TO REMAIN BELOW THE 6-INCH THRESHOLD FOR WARNING. WATCHES CONTINUE
AND HAVE BEEN EXTENDED TO THE S-COAST TO COVER FOR THE UNCERTAINTY
OF THE AREA EITHER FALLING WITHIN OR IN EXCESS OF ADVISORY-LEVEL
SNOWS. AGAIN...6+ INCH AMOUNTS ARE ANTICIPATED BUT EXACTLY WHERE IS
UNCERTAIN.

5) CLOSING NOTES...

SOME CONCERN FOR THE EARLY MONDAY MORNING COMMUTE FOR E/SE MA AND
RI. WHILE MOST OF THE SNOW IS EXPECTED TO BE IMMEDIATELY OFFSHORE
WITH SUNRISE MONDAY...COMMUTERS COULD ENCOUNTER SLICK AND SLIPPERY
ROAD CONDITIONS. SNOW COULD POSSIBLY LINGER OVER SE MA SO THERE IS
THE POTENTIAL FOR REDUCED VISIBILITIES.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
BIG PICTURE... THE BROAD UPPER FLOW SHOWS A RIDGE IN THE EAST AND
TROUGH IN THE WEST WITH A WEST SOUTHWEST FLOW FROM THE PLAINS TO THE
EASTERN USA COAST. WITHIN THIS FLOW ARE BOTH NORTHERN AND SOUTHERN
STREAMS AT THE START OF THE WEEK. THE WESTERN TROUGH MIGRATES EAST
DURING THE MIDWEEK AT WHICH TIME THE TWO STREAMS MERGE TO FORM A 140-
160 KT UPPER JET FEEDING NORTHEAST INTO THE GREAT LAKES AND ST
LAWRENCE VALLEY. THIS JET LINGERS OVER OR NEAR NEW ENGLAND THURSDAY-
FRIDAY BEFORE MOVING OFF. THE WESTERN TROUGH MOVES ACROSS NEW
ENGLAND BY THE END OF THE WEEK.

DAILIES...

MONDAY... SUNDAY STORM MOVES OFF PAST NOVA SCOTIA WHILE THE
SUPPORTING UPPER SHORTWAVE AND COLD POOL SWING ACROSS NEW ENGLAND.
THE COOLEST AIR ALOFT IS IN NORTHERN NEW ENGLAND WHILE LEFTOVER
MOISTURE LINGERS BELOW 800 MB THROUGH THE DAY. THE GFS IS FASTER
THAN THE ECMWF IN BRINGING RISING PRESSURE TO THE REGION BUT HAVE 1
MB/HOUR RISES HERE BY EVENING. PUT TOGETHER...EXPECT A CLEARING
TREND BUT WITH LEFTOVER CLOUDS ESPECIALLY NORTH OF THE MASS PIKE.
SUSTAINED NORTHWEST WINDS SHOULD RISE TO 15-20 KTS. MIXING REACHES
TO AT LEAST 850 MB AND POSSIBLY A LITTLE HIGHER...WHICH SUPPORTS
GUSTS TO AT LEAST 30 KNOTS AND POSSIBLY 35 KNOTS. TEMPS AT 850 MB
WILL BE -11C TO -14C...MIXING THIS TO THE SURFACE WOULD SUPPORT MAX
SFC TEMPS IN THE 30S. MIN TEMPERATURES UPSTREAM THIS MORNING WERE IN
THE SINGLE NUMBERS WITH A FEW SPOTS BELOW ZERO. WITH LIGHT PRESSURE
GRADIENT ESP IN THE WEST...WE TENDED A FEW DEGREES COOLER THAN
CONSENSUS.

TUESDAY-WEDNESDAY... HIGH PRESSURE IN CONTROL MUCH OF TUESDAY BUT
MOVING OFFSHORE DURING THE AFTERNOON. CROSS SECTIONS SHOW INCREASING
MOISTURE AT MID AND HIGH CLOUD LEVEL...SO INCREASING HIGH CLOUDS.
SYSTEM MOVING INTO THE GREAT LAKES SPREADS PCPN INTO NEW YORK...BUT
WARM ADVECTION LIFT REMAINS MOSTLY TO OUR WEST THROUGH THE
AFTERNOON. SOME LIFT FORECAST AT 290K /ABOUT 730 MB AT THE TIME/ BUT
NONE BELOW THAT. MEANWHILE DEWPOINTS IN THE SINGLE NUMBERS PROGRESS
INTO THE TEENS DURING THE DAY...BUT ENOUGH OF A TEMP/DEWPOINT SPREAD
TO SLOW THE ADVANCE OF ANY PCPN FROM THE CLOUDS BY A FEW HOURS.

WARM ADVECTION LIFT MUCH OF THE NIGHT SUPPORTS THE IDEA OF PCPN.
TEMPERATURES START COLD DURING THE EVENING BUT SHOULD RISE
OVERNIGHT. THE QUESTION REMAINS AS TO HOW HIGH THEY WILL CLIMB. EVEN
WITH THE SURFACE SYSTEM TRACKING UP THE ST LAWRENCE VALLEY THERE IS
COLD GROUND AND A COLD SNOWPACK. THIS WOULD ALLOW THE WARMER TEMPS
TO SCREAM OVERHEAD WHILE THE IMMEDIATE SURFACE REMAINS SEVERAL
DEGREES COLDER. WE TRIMMED TEMPS BACK A LITTLE FROM MODEL
VALUES...BUT LOW CONFIDENCE AT THIS TIME DUE TO THE POTENTIAL THAT
SURFACE TEMPS COULD REMAIN IN THE 30S.

QPF FORECASTS RANGE FROM 0.50 TO 1.00 INCHES WITH THE HIGHER AMOUNTS
TENDING TOWARD THE SOUTH COAST. THIS POINTS TO A MESSY STORM WITH
INITIAL SNOW ACCUMS OF SEVERAL INCHES FOLLOWED BY A CHANGE TO
MEASURABLE ICE ACCUMULATION AND THEN A CHANGE TO RAIN WITH
POTENTIAL FOR POOR DRAINAGE FLOODING IN BETWEEN THE SNOW BANKS.

THE COLD FRONT SHOULD MOVE THROUGH DURING THE AFTERNOON/EVENING WITH
A SHIFT TO NORTHWEST WINDS. THIS WILL CHANGE THE PCPN BACK TO SNOW
BEFORE TAPERING OFF.

THURSDAY...DIFFERENCES IN THE GFS AND ECMWF IN HANDING THE UPPER JET.
THE ECMWF MOVES THE JET OFFSHORE AND PUTS SOUTHERN NEW ENGLAND
INTO SUBSIDENCE. THE GFS MAINTAINS THE JET OVERHEAD WITH OUR AREA
IN THE RIGHT ENTRANCE REGION. THE FIRST SCENARIO ENDS THE PCPN AND
COOLS THE AIR. THE SECOND SCENARIO WOULD SUPPORT LIFT AND GENERATE
WAVES ALONG THE DEPARTING COLD FRONT...MAINTAINING A CHANCE OF
SNOW OVER AT LEAST SOUTHERN PARTS OF OUR AREA. OUR THURSDAY
FORECAST TENDS TOWARD THE LATTER FOR NOW.

FRIDAY-SATURDAY... HIGH PRESSURE BUILDS OVER THE REGION THURSDAY
NIGHT AND FRIDAY WITH CLEARING SKIES AND A BRIEF PERIOD OF COLD AIR.
TEMPS ALOFT TREND UP ABOUT 10C ON SATURDAY SUGGESTING LESS CHILL AT
THE SURFACE. ANOTHER COLD FRONT APPROACHES THE ST LAWRENCE VALLEY
AND COULD SPREAD SOME CLOUDS INTO OUR AREA SATURDAY
AFTERNOON/EVENING. BUT PCPN CHANCES LOOK SMALL.

&&

.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /THROUGH MONDAY MORNING/...

TONIGHT THROUGH SUNDAY MIDDAY...HIGH CONFIDENCE.

VFR. LOWERING AND THICKENING CLOUDS SUNDAY MORNING INTO MIDDAY.

SUNDAY AFTERNOON INTO MONDAY MORNING...MODERATE CONFIDENCE.

SNOW OVERSPREADS THE REGION W-E. CIGS/VSBYS DETERIORATE TO MVFR-
IFR BY EARLY EVENING...WIDESPREAD IFR-LIFR SUNDAY NIGHT. SN TO MIX
WITH OR CHANGE TO FZRA ACROSS OFFSHORE ISLAND TERMINALS OVERNIGHT.
PRECIP ENDS W-E TOWARD DAYBREAK MONDAY....CONDITIONS IMPROVE.

KBOS TAF...MODERATE CONFIDENCE. TRENDS CERTAIN BUT NOT SO MUCH THE
ACTUAL TIMING OF IMPACTS.

KBDL TAF...MODERATE CONFIDENCE. TRENDS CERTAIN BUT NOT SO MUCH
THE ACTUAL TIMING OF IMPACTS.

OUTLOOK...MONDAY THROUGH THURSDAY...

MONDAY... HIGH CONFIDENCE. SOME IFR/MVFR IN SNOW EARLY MORNING BUT
OTHERWISE CONDITIONS WILL IMPROVE TO VFR DURING THE MORNING.
NORTHWEST WINDS WILL INCREASE WITH GUSTS AROUND 30 KNOTS BY MIDDAY.
VFR AND DIMINISHING WIND MONDAY NIGHT.

TUESDAY...MODERATE CONFIDENCE. VFR DURING THE DAY WITH INCREASING
SKY COVER. MVFR TUESDAY EVENING BECOMING IFR/LIFR OVERNIGHT IN
DEVELOPING SNOW AND FREEZING RAIN.

WEDNESDAY...MODERATE CONFIDENCE. IFR/LIFR IN RAIN AND FREEZING RAIN.

THURSDAY...LOW CONFIDENCE. VFR NORTH OF A HFD-BOS LINE. MVFR CIGS
AND AREAS OF MVFR/IFR VSBYS IN SNOW.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /THROUGH MONDAY MORNING/...HIGH CONFIDENCE.

HIGH PRESSURE NEARBY WILL KEEP WINDS/SEAS WELL BELOW SMALL CRAFT
ADVISORY THRESHOLDS INTO SUNDAY MORNING. A WEAK WAVE OF LOW
PRESSURE MOVES ACROSS THE WATERS LATE SUNDAY INTO SUNDAY NIGHT...
BUT WEAK PRESSURE GRADIENT SHOULD KEEP WINDS/SEAS BELOW SMALL
CRAFT THRESHOLDS.

OUTLOOK...MONDAY THROUGH THURSDAY..MODERATE CONFIDENCE.

MONDAY...WEST TO NORTHWEST WINDS INCREASE WITH FREQUENT GUSTS TO
GALE FORCE ESPECIALLY AWAY FROM THE NEARSHORE. THIS COULD GENERATE
SOME LIGHT FREEZING SPRAY ESPECIALLY EARLY MONDAY NIGHT. SEAS 5
TO 10 FEET. WINDS AND SEAS DIMINISH MONDAY NIGHT. A GALE WARNING
MAY BE NEEDED.

TUESDAY... LINGERING 5 FOOT SEAS ON THE OUTER WATERS BUT DIMINISHING
DURING THE MORNING.  WINDS AND SEAS INCREASE AGAIN TUESDAY NIGHT
AFTER MIDNIGHT AHEAD OF A GREAT LAKES COLD FRONT. SOUTH WINDS WILL
APPROACH 25 KNOTS WITH SEAS BUILDING TO 5 TO 8 FEET. VSBYS WILL
BE REDUCED IN SNOW CHANGING TO RAIN.

WEDNESDAY...SOUTHWEST WINDS WITH GUSTS 25-30 KNOTS.  SEAS BUILDING
TO 6 TO 12 FEET. REDUCED VSBYS IN RAIN. A SMALL CRAFT ADVISORY MAY
BE NEEDED.

THURSDAY...NORTHWEST WINDS WILL GUST TO 25 KNOTS...AND SEAS 5 TO 8
FEET. BOTH SHOULD DIMINISH TOWARD EVENING.  A SMALL CRAFT ADVISORY
MAY BE NEEDED.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY
     MORNING FOR CTZ002>004.
MA...WINTER WEATHER ADVISORY FROM NOON SUNDAY TO 7 AM EST MONDAY
     FOR MAZ002>008-010-014-023-024-026.
     WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY
     MORNING FOR MAZ009-011>013-015>022.
RI...WINTER WEATHER ADVISORY FROM NOON SUNDAY TO 7 AM EST MONDAY
     FOR RIZ008.
     WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY
     MORNING FOR RIZ001>007.
MARINE...NONE.

&&

$$
SYNOPSIS...WTB/SIPPRELL
NEAR TERM...FRANK
SHORT TERM...SIPPRELL
LONG TERM...WTB
AVIATION...WTB/SIPPRELL
MARINE...WTB/SIPPRELL



000
FXUS61 KBOX 010217
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
917 PM EST SAT FEB 28 2015

.SYNOPSIS...

A FAST MOVING LOW PRESSURE SYSTEM WILL BRING ACCUMULATING SNOW TO
THE REGION LATE SUNDAY INTO SUNDAY NIGHT...WITH THE HIGHEST AMOUNTS
EXPECTED SOUTH OF THE MASSACHUSETTS TURNPIKE AND AWAY FROM THE
IMMEDIATE SOUTH COAST. HIGH PRESSURE BRINGS DRY COLD AIR FOR THE
EARLY WEEK. LOW PRESSURE FROM NORTHERN CANADA AND ASSOCIATED LOW
FORMING OVER THE PLAINS MONDAY WILL MERGE...THEN PASS WEST AND
NORTH OF NEW ENGLAND. THIS WILL SWING A COLD FRONT ACROSS THE
REGION ON WEDNESDAY. DRY AND COLD WEATHER RETURNS FOR THE END OF
THE WEEK.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...

915 PM UPDATE...

CLEAR SKIES...LIGHT WINDS AND DEEP SNOW PACK WERE RESULTING IN
ANOTHER EXCELLENT NIGHT OF RADIATIONAL COOLING THIS EVENING WITH A
WIDE RANGE IN TEMPERATURES.  LOW TEMPS WILL BOTTOM OUT BETWEEN 5 AND
10 BELOW ZERO ACROSS THE NORMALLY COLDEST OUTLYING LOCATIONS.  OTHER
AREAS THAT DO NOT RADIATE AS WELL SUCH AS THE HIGHER TERRAIN/URBAN
CENTERS WILL SEE LOWS MAINLY IN THE SINGLE DIGITS...TO LOWER TEENS.

THESE LOW TEMPS WILL LIKELY OCCUR A FEW HOURS BEFORE SUNRISE AND
THEN LEVEL OFF OR RISE BY DAYBREAK AS SOME MID/HIGH LEVEL CLOUDINESS
MOVES IN FROM THE WEST.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
*/ SUNDAY MORNING INTO MIDDAY...

QUIET WEATHER. CLOUDS THICKENING AS WINDS INCREASE OUT OF THE S.
WILL SEE TEMPERATURES GRADUALLY MODERATE INTO THE MID- TO UPPER-20S.

*/ SUNDAY AFTERNOON INTO EARLY MONDAY MORNING...

1) HIGHLIGHTS...

 - SNOW SUNDAY AFTERNOON INTO MONDAY MORNING
 - GREATEST INTENSITY SUNDAY EVENING AND OVERNIGHT
 - 6+ INCH SNOWFALLS EXPECTED BUT EXACTLY WHERE REMAINS UNCERTAIN
 - ANNOYINGLY...FORECAST GUIDANCE CONTINUES TO WOBBLE

1) OVERVIEW...

BROAD ISENTROPIC OVER-RUNNING EVENT OF GULF MOISTURE ALONG THE 275-
295K SURFACES AMPLIFIED BY A N-STREAM IMPULSE DURING THE TIMEFRAME
POSSIBLY INVOKING AN AREA OF LOW PRESSURE THAT SKIRTS ALONG THE S-
COAST SUBSEQUENTLY ENHANCING LOW-LEVEL WIND PROFILE. LIGHT-MODERATE
SNOWFALL IS ANTICIPATED WITH LOCALLY HEAVIER AMOUNTS. THE INTENSE
PORTION OF SNOWFALL IS EXPECTED SUNDAY EVENING AND OVERNIGHT ENDING
EARLY MONDAY MORNING.

MODEL PREFERENCE GIVEN TO THE ECMWF/GFS/REGIONAL CANADIAN WHICH WILL
SERVE AS THE CONSENSUS OF GUIDANCE FOR THIS DISCUSSION. THE 28.12Z
NAM WAS CONSIDERED AN OUTLIER WITH ITS AGGRESSIVE-MODE AND SECONDARY
LOW DEVELOPMENT JUST OFFSHORE.

2) PRECIPITATION-TYPE...

EVALUATING THERMAL FIELDS...BLEND OF FORECAST CONSENSUS PUTS THE
-2C H925 ISOTHERM W-E ACROSS S-TIER OF CT/RI AND ACROSS SE MA WITH
THE 0C H85 ISOTHERM JUST S OF LONG-ISLAND AND NANTUCKET COASTLINES.
THE CONSENSUS OF 1000-850 MB CRITICAL THICKNESSES LAYS RIGHT ALONG
THE IMMEDIATE S-COAST OF LONG-ISLAND AND CAPE COD.

AN ALL SNOW-EVENT WHEN CONSIDERING DYNAMIC-COOLING/WETBULBING OF THE
LOW-LEVELS AHEAD OF THE EVENT. THERE IS PERHAPS A CHANCE OF A BRIEF
MIX-OVER TO RAIN/FREEZING RAIN ACROSS THE CAPE AND ISLANDS AS S-FLOW
AT THE SURFACE IS POSSIBLY ABLE TO NUDGE ABOVE-FREEZING TEMPERATURES
N. YET AS WE ARE IN A FROZEN TUNDRA...WITH ANY RAIN IT WOULD LIKELY
FREEZE ON SURFACES WHICH ARE QUITE COLD. THUS FREEZING RAIN PREVAILS
OVER RAIN IN THE FORECAST.

3) SNOWFALL...

FORECAST CONSENSUS OF A 0.3-0.6 N-S PRECIPITATION EVENT WITH A N-S
SNOW-TO-LIQUID RATIO GRADIENT RANGING FROM 15:1 TO 10:1 YIELDS HIGH-
END SNOW ADVISORY CRITERIA WITH SNOWFALL AMOUNTS RANGING ON AVERAGE
AROUND 3-6 INCHES. AREAS OF 6+ INCHES ARE EXPECTED...ESPECIALLY FROM
CENTRAL-CT E INTO SE-MA /INCLUDING THE UPPER-CAPE/. A CHALLENGE AND
A LOT OF UNCERTAINTY WITH RESPECT TO HEADLINES AND DECISION-MAKING.

EVALUATING LOW-LEVEL THERMAL PROFILES TOWARDS SNOW-TO-LIQUID RATIOS
DERIVED VIA A COBB-TECHNIQUE...WITH THE GREATEST LIFT OCCURRING
JUST BENEATH OR WITHIN THE DENDRITIC-GROWTH ZONE BASED ON A
CONSENSUS OF BUFKIT GFS PROFILES...ESPECIALLY IN HEAVIER- PRECIP
AREAS...BELIEVE THE SNOW WILL RANGE SOMEWHERE BETWEEN A WET AND
FLUFFY SNOW. SNOW PROPERTIES FROM FLUFFY TO WET LIKELY SIMILAR TO
THE N-S GRADIENT AS OUTLINED ABOVE.

4) HEADLINES...

HATE A WOBBLING FORECAST WHICH IS TYPICAL WITH SUCH SMALL EVENTS.
UNCERTAINTY DERIVES FROM LOW-LEVEL THERMAL PROFILES AND PRECIP
AMOUNTS. SURELY EXPECTING SNOW...BUT WITH ANY SHIFT N-S OF COLDER
AIR AND/OR PRECIPITATION AMOUNTS RESULTS IN AREAS SHIFTING FROM
ADVISORY TO WARNING...OR VICE VERSA. ENOUGH TO JUST PULL YOUR HAIR
OUT. THEN THERE IS THE TIMING OF THE SYSTEM THAT HAS SPED UP
SLIGHTLY. A SHORTER RESIDENCE TIME OF COURSE WOULD YIELD LESSER
SNOWFALL AMOUNTS. QUITE A CHALLENGING FORECAST RIGHT ON THE CUSP
OF HEADLINE THRESHOLDS.

THE EVENT DOES TAKE PLACE MAINLY FROM SUNDAY EVENING INTO THE EARLY
MORNING HOURS ON MONDAY DURING WHICH TIME THERE IS NOT MUCH TRAFFIC
ON THE ROAD. IS THIS A HIGH IMPACT EVENT THAT WARRANTS WARNINGS? A
QUESTION TO STRUGGLE WITH AS WARNINGS ARE NECESSARY WHEN WE ARE
CONFIDENT IN MEETING OR EXCEEDING 6+ INCH CRITERIA. YET THE QUESTION
IN FRONT OF US IS WHERE WILL THE HIGHER AMOUNTS OF SNOW FOCUS? HAVE
TO MAKE SOME SORT OF CALL...THE NEEDS OF THE MANY OUTWEIGH THE NEEDS
OF THE FEW.

ADVISORIES POSTED WHERE THERE IS HIGH CONFIDENCE OF SNOW BUT LIKELY
TO REMAIN BELOW THE 6-INCH THRESHOLD FOR WARNING. WATCHES CONTINUE
AND HAVE BEEN EXTENDED TO THE S-COAST TO COVER FOR THE UNCERTAINTY
OF THE AREA EITHER FALLING WITHIN OR IN EXCESS OF ADVISORY-LEVEL
SNOWS. AGAIN...6+ INCH AMOUNTS ARE ANTICIPATED BUT EXACTLY WHERE IS
UNCERTAIN.

5) CLOSING NOTES...

SOME CONCERN FOR THE EARLY MONDAY MORNING COMMUTE FOR E/SE MA AND
RI. WHILE MOST OF THE SNOW IS EXPECTED TO BE IMMEDIATELY OFFSHORE
WITH SUNRISE MONDAY...COMMUTERS COULD ENCOUNTER SLICK AND SLIPPERY
ROAD CONDITIONS. SNOW COULD POSSIBLY LINGER OVER SE MA SO THERE IS
THE POTENTIAL FOR REDUCED VISIBILITIES.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
BIG PICTURE... THE BROAD UPPER FLOW SHOWS A RIDGE IN THE EAST AND
TROUGH IN THE WEST WITH A WEST SOUTHWEST FLOW FROM THE PLAINS TO THE
EASTERN USA COAST. WITHIN THIS FLOW ARE BOTH NORTHERN AND SOUTHERN
STREAMS AT THE START OF THE WEEK. THE WESTERN TROUGH MIGRATES EAST
DURING THE MIDWEEK AT WHICH TIME THE TWO STREAMS MERGE TO FORM A 140-
160 KT UPPER JET FEEDING NORTHEAST INTO THE GREAT LAKES AND ST
LAWRENCE VALLEY. THIS JET LINGERS OVER OR NEAR NEW ENGLAND THURSDAY-
FRIDAY BEFORE MOVING OFF. THE WESTERN TROUGH MOVES ACROSS NEW
ENGLAND BY THE END OF THE WEEK.

DAILIES...

MONDAY... SUNDAY STORM MOVES OFF PAST NOVA SCOTIA WHILE THE
SUPPORTING UPPER SHORTWAVE AND COLD POOL SWING ACROSS NEW ENGLAND.
THE COOLEST AIR ALOFT IS IN NORTHERN NEW ENGLAND WHILE LEFTOVER
MOISTURE LINGERS BELOW 800 MB THROUGH THE DAY. THE GFS IS FASTER
THAN THE ECMWF IN BRINGING RISING PRESSURE TO THE REGION BUT HAVE 1
MB/HOUR RISES HERE BY EVENING. PUT TOGETHER...EXPECT A CLEARING
TREND BUT WITH LEFTOVER CLOUDS ESPECIALLY NORTH OF THE MASS PIKE.
SUSTAINED NORTHWEST WINDS SHOULD RISE TO 15-20 KTS. MIXING REACHES
TO AT LEAST 850 MB AND POSSIBLY A LITTLE HIGHER...WHICH SUPPORTS
GUSTS TO AT LEAST 30 KNOTS AND POSSIBLY 35 KNOTS. TEMPS AT 850 MB
WILL BE -11C TO -14C...MIXING THIS TO THE SURFACE WOULD SUPPORT MAX
SFC TEMPS IN THE 30S. MIN TEMPERATURES UPSTREAM THIS MORNING WERE IN
THE SINGLE NUMBERS WITH A FEW SPOTS BELOW ZERO. WITH LIGHT PRESSURE
GRADIENT ESP IN THE WEST...WE TENDED A FEW DEGREES COOLER THAN
CONSENSUS.

TUESDAY-WEDNESDAY... HIGH PRESSURE IN CONTROL MUCH OF TUESDAY BUT
MOVING OFFSHORE DURING THE AFTERNOON. CROSS SECTIONS SHOW INCREASING
MOISTURE AT MID AND HIGH CLOUD LEVEL...SO INCREASING HIGH CLOUDS.
SYSTEM MOVING INTO THE GREAT LAKES SPREADS PCPN INTO NEW YORK...BUT
WARM ADVECTION LIFT REMAINS MOSTLY TO OUR WEST THROUGH THE
AFTERNOON. SOME LIFT FORECAST AT 290K /ABOUT 730 MB AT THE TIME/ BUT
NONE BELOW THAT. MEANWHILE DEWPOINTS IN THE SINGLE NUMBERS PROGRESS
INTO THE TEENS DURING THE DAY...BUT ENOUGH OF A TEMP/DEWPOINT SPREAD
TO SLOW THE ADVANCE OF ANY PCPN FROM THE CLOUDS BY A FEW HOURS.

WARM ADVECTION LIFT MUCH OF THE NIGHT SUPPORTS THE IDEA OF PCPN.
TEMPERATURES START COLD DURING THE EVENING BUT SHOULD RISE
OVERNIGHT. THE QUESTION REMAINS AS TO HOW HIGH THEY WILL CLIMB. EVEN
WITH THE SURFACE SYSTEM TRACKING UP THE ST LAWRENCE VALLEY THERE IS
COLD GROUND AND A COLD SNOWPACK. THIS WOULD ALLOW THE WARMER TEMPS
TO SCREAM OVERHEAD WHILE THE IMMEDIATE SURFACE REMAINS SEVERAL
DEGREES COLDER. WE TRIMMED TEMPS BACK A LITTLE FROM MODEL
VALUES...BUT LOW CONFIDENCE AT THIS TIME DUE TO THE POTENTIAL THAT
SURFACE TEMPS COULD REMAIN IN THE 30S.

QPF FORECASTS RANGE FROM 0.50 TO 1.00 INCHES WITH THE HIGHER AMOUNTS
TENDING TOWARD THE SOUTH COAST. THIS POINTS TO A MESSY STORM WITH
INITIAL SNOW ACCUMS OF SEVERAL INCHES FOLLOWED BY A CHANGE TO
MEASURABLE ICE ACCUMULATION AND THEN A CHANGE TO RAIN WITH
POTENTIAL FOR POOR DRAINAGE FLOODING IN BETWEEN THE SNOW BANKS.

THE COLD FRONT SHOULD MOVE THROUGH DURING THE AFTERNOON/EVENING WITH
A SHIFT TO NORTHWEST WINDS. THIS WILL CHANGE THE PCPN BACK TO SNOW
BEFORE TAPERING OFF.

THURSDAY...DIFFERENCES IN THE GFS AND ECMWF IN HANDING THE UPPER JET.
THE ECMWF MOVES THE JET OFFSHORE AND PUTS SOUTHERN NEW ENGLAND
INTO SUBSIDENCE. THE GFS MAINTAINS THE JET OVERHEAD WITH OUR AREA
IN THE RIGHT ENTRANCE REGION. THE FIRST SCENARIO ENDS THE PCPN AND
COOLS THE AIR. THE SECOND SCENARIO WOULD SUPPORT LIFT AND GENERATE
WAVES ALONG THE DEPARTING COLD FRONT...MAINTAINING A CHANCE OF
SNOW OVER AT LEAST SOUTHERN PARTS OF OUR AREA. OUR THURSDAY
FORECAST TENDS TOWARD THE LATTER FOR NOW.

FRIDAY-SATURDAY... HIGH PRESSURE BUILDS OVER THE REGION THURSDAY
NIGHT AND FRIDAY WITH CLEARING SKIES AND A BRIEF PERIOD OF COLD AIR.
TEMPS ALOFT TREND UP ABOUT 10C ON SATURDAY SUGGESTING LESS CHILL AT
THE SURFACE. ANOTHER COLD FRONT APPROACHES THE ST LAWRENCE VALLEY
AND COULD SPREAD SOME CLOUDS INTO OUR AREA SATURDAY
AFTERNOON/EVENING. BUT PCPN CHANCES LOOK SMALL.

&&

.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /THROUGH MONDAY MORNING/...

TONIGHT THROUGH SUNDAY MIDDAY...HIGH CONFIDENCE.

VFR. LOWERING AND THICKENING CLOUDS SUNDAY MORNING INTO MIDDAY.

SUNDAY AFTERNOON INTO MONDAY MORNING...MODERATE CONFIDENCE.

SNOW OVERSPREADS THE REGION W-E. CIGS/VSBYS DETERIORATE TO MVFR-
IFR BY EARLY EVENING...WIDESPREAD IFR-LIFR SUNDAY NIGHT. SN TO MIX
WITH OR CHANGE TO FZRA ACROSS OFFSHORE ISLAND TERMINALS OVERNIGHT.
PRECIP ENDS W-E TOWARD DAYBREAK MONDAY....CONDITIONS IMPROVE.

KBOS TAF...MODERATE CONFIDENCE. TRENDS CERTAIN BUT NOT SO MUCH THE
ACTUAL TIMING OF IMPACTS.

KBDL TAF...MODERATE CONFIDENCE. TRENDS CERTAIN BUT NOT SO MUCH
THE ACTUAL TIMING OF IMPACTS.

OUTLOOK...MONDAY THROUGH THURSDAY...

MONDAY... HIGH CONFIDENCE. SOME IFR/MVFR IN SNOW EARLY MORNING BUT
OTHERWISE CONDITIONS WILL IMPROVE TO VFR DURING THE MORNING.
NORTHWEST WINDS WILL INCREASE WITH GUSTS AROUND 30 KNOTS BY MIDDAY.
VFR AND DIMINISHING WIND MONDAY NIGHT.

TUESDAY...MODERATE CONFIDENCE. VFR DURING THE DAY WITH INCREASING
SKY COVER. MVFR TUESDAY EVENING BECOMING IFR/LIFR OVERNIGHT IN
DEVELOPING SNOW AND FREEZING RAIN.

WEDNESDAY...MODERATE CONFIDENCE. IFR/LIFR IN RAIN AND FREEZING RAIN.

THURSDAY...LOW CONFIDENCE. VFR NORTH OF A HFD-BOS LINE. MVFR CIGS
AND AREAS OF MVFR/IFR VSBYS IN SNOW.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /THROUGH MONDAY MORNING/...HIGH CONFIDENCE.

HIGH PRESSURE NEARBY WILL KEEP WINDS/SEAS WELL BELOW SMALL CRAFT
ADVISORY THRESHOLDS INTO SUNDAY MORNING. A WEAK WAVE OF LOW
PRESSURE MOVES ACROSS THE WATERS LATE SUNDAY INTO SUNDAY NIGHT...
BUT WEAK PRESSURE GRADIENT SHOULD KEEP WINDS/SEAS BELOW SMALL
CRAFT THRESHOLDS.

OUTLOOK...MONDAY THROUGH THURSDAY..MODERATE CONFIDENCE.

MONDAY...WEST TO NORTHWEST WINDS INCREASE WITH FREQUENT GUSTS TO
GALE FORCE ESPECIALLY AWAY FROM THE NEARSHORE. THIS COULD GENERATE
SOME LIGHT FREEZING SPRAY ESPECIALLY EARLY MONDAY NIGHT. SEAS 5
TO 10 FEET. WINDS AND SEAS DIMINISH MONDAY NIGHT. A GALE WARNING
MAY BE NEEDED.

TUESDAY... LINGERING 5 FOOT SEAS ON THE OUTER WATERS BUT DIMINISHING
DURING THE MORNING.  WINDS AND SEAS INCREASE AGAIN TUESDAY NIGHT
AFTER MIDNIGHT AHEAD OF A GREAT LAKES COLD FRONT. SOUTH WINDS WILL
APPROACH 25 KNOTS WITH SEAS BUILDING TO 5 TO 8 FEET. VSBYS WILL
BE REDUCED IN SNOW CHANGING TO RAIN.

WEDNESDAY...SOUTHWEST WINDS WITH GUSTS 25-30 KNOTS.  SEAS BUILDING
TO 6 TO 12 FEET. REDUCED VSBYS IN RAIN. A SMALL CRAFT ADVISORY MAY
BE NEEDED.

THURSDAY...NORTHWEST WINDS WILL GUST TO 25 KNOTS...AND SEAS 5 TO 8
FEET. BOTH SHOULD DIMINISH TOWARD EVENING.  A SMALL CRAFT ADVISORY
MAY BE NEEDED.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY
     MORNING FOR CTZ002>004.
MA...WINTER WEATHER ADVISORY FROM NOON SUNDAY TO 7 AM EST MONDAY
     FOR MAZ002>008-010-014-023-024-026.
     WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY
     MORNING FOR MAZ009-011>013-015>022.
RI...WINTER WEATHER ADVISORY FROM NOON SUNDAY TO 7 AM EST MONDAY
     FOR RIZ008.
     WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY
     MORNING FOR RIZ001>007.
MARINE...NONE.

&&

$$
SYNOPSIS...WTB/SIPPRELL
NEAR TERM...FRANK
SHORT TERM...SIPPRELL
LONG TERM...WTB
AVIATION...WTB/SIPPRELL
MARINE...WTB/SIPPRELL



000
FXUS61 KBOX 010217
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
917 PM EST SAT FEB 28 2015

.SYNOPSIS...

A FAST MOVING LOW PRESSURE SYSTEM WILL BRING ACCUMULATING SNOW TO
THE REGION LATE SUNDAY INTO SUNDAY NIGHT...WITH THE HIGHEST AMOUNTS
EXPECTED SOUTH OF THE MASSACHUSETTS TURNPIKE AND AWAY FROM THE
IMMEDIATE SOUTH COAST. HIGH PRESSURE BRINGS DRY COLD AIR FOR THE
EARLY WEEK. LOW PRESSURE FROM NORTHERN CANADA AND ASSOCIATED LOW
FORMING OVER THE PLAINS MONDAY WILL MERGE...THEN PASS WEST AND
NORTH OF NEW ENGLAND. THIS WILL SWING A COLD FRONT ACROSS THE
REGION ON WEDNESDAY. DRY AND COLD WEATHER RETURNS FOR THE END OF
THE WEEK.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...

915 PM UPDATE...

CLEAR SKIES...LIGHT WINDS AND DEEP SNOW PACK WERE RESULTING IN
ANOTHER EXCELLENT NIGHT OF RADIATIONAL COOLING THIS EVENING WITH A
WIDE RANGE IN TEMPERATURES.  LOW TEMPS WILL BOTTOM OUT BETWEEN 5 AND
10 BELOW ZERO ACROSS THE NORMALLY COLDEST OUTLYING LOCATIONS.  OTHER
AREAS THAT DO NOT RADIATE AS WELL SUCH AS THE HIGHER TERRAIN/URBAN
CENTERS WILL SEE LOWS MAINLY IN THE SINGLE DIGITS...TO LOWER TEENS.

THESE LOW TEMPS WILL LIKELY OCCUR A FEW HOURS BEFORE SUNRISE AND
THEN LEVEL OFF OR RISE BY DAYBREAK AS SOME MID/HIGH LEVEL CLOUDINESS
MOVES IN FROM THE WEST.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
*/ SUNDAY MORNING INTO MIDDAY...

QUIET WEATHER. CLOUDS THICKENING AS WINDS INCREASE OUT OF THE S.
WILL SEE TEMPERATURES GRADUALLY MODERATE INTO THE MID- TO UPPER-20S.

*/ SUNDAY AFTERNOON INTO EARLY MONDAY MORNING...

1) HIGHLIGHTS...

 - SNOW SUNDAY AFTERNOON INTO MONDAY MORNING
 - GREATEST INTENSITY SUNDAY EVENING AND OVERNIGHT
 - 6+ INCH SNOWFALLS EXPECTED BUT EXACTLY WHERE REMAINS UNCERTAIN
 - ANNOYINGLY...FORECAST GUIDANCE CONTINUES TO WOBBLE

1) OVERVIEW...

BROAD ISENTROPIC OVER-RUNNING EVENT OF GULF MOISTURE ALONG THE 275-
295K SURFACES AMPLIFIED BY A N-STREAM IMPULSE DURING THE TIMEFRAME
POSSIBLY INVOKING AN AREA OF LOW PRESSURE THAT SKIRTS ALONG THE S-
COAST SUBSEQUENTLY ENHANCING LOW-LEVEL WIND PROFILE. LIGHT-MODERATE
SNOWFALL IS ANTICIPATED WITH LOCALLY HEAVIER AMOUNTS. THE INTENSE
PORTION OF SNOWFALL IS EXPECTED SUNDAY EVENING AND OVERNIGHT ENDING
EARLY MONDAY MORNING.

MODEL PREFERENCE GIVEN TO THE ECMWF/GFS/REGIONAL CANADIAN WHICH WILL
SERVE AS THE CONSENSUS OF GUIDANCE FOR THIS DISCUSSION. THE 28.12Z
NAM WAS CONSIDERED AN OUTLIER WITH ITS AGGRESSIVE-MODE AND SECONDARY
LOW DEVELOPMENT JUST OFFSHORE.

2) PRECIPITATION-TYPE...

EVALUATING THERMAL FIELDS...BLEND OF FORECAST CONSENSUS PUTS THE
-2C H925 ISOTHERM W-E ACROSS S-TIER OF CT/RI AND ACROSS SE MA WITH
THE 0C H85 ISOTHERM JUST S OF LONG-ISLAND AND NANTUCKET COASTLINES.
THE CONSENSUS OF 1000-850 MB CRITICAL THICKNESSES LAYS RIGHT ALONG
THE IMMEDIATE S-COAST OF LONG-ISLAND AND CAPE COD.

AN ALL SNOW-EVENT WHEN CONSIDERING DYNAMIC-COOLING/WETBULBING OF THE
LOW-LEVELS AHEAD OF THE EVENT. THERE IS PERHAPS A CHANCE OF A BRIEF
MIX-OVER TO RAIN/FREEZING RAIN ACROSS THE CAPE AND ISLANDS AS S-FLOW
AT THE SURFACE IS POSSIBLY ABLE TO NUDGE ABOVE-FREEZING TEMPERATURES
N. YET AS WE ARE IN A FROZEN TUNDRA...WITH ANY RAIN IT WOULD LIKELY
FREEZE ON SURFACES WHICH ARE QUITE COLD. THUS FREEZING RAIN PREVAILS
OVER RAIN IN THE FORECAST.

3) SNOWFALL...

FORECAST CONSENSUS OF A 0.3-0.6 N-S PRECIPITATION EVENT WITH A N-S
SNOW-TO-LIQUID RATIO GRADIENT RANGING FROM 15:1 TO 10:1 YIELDS HIGH-
END SNOW ADVISORY CRITERIA WITH SNOWFALL AMOUNTS RANGING ON AVERAGE
AROUND 3-6 INCHES. AREAS OF 6+ INCHES ARE EXPECTED...ESPECIALLY FROM
CENTRAL-CT E INTO SE-MA /INCLUDING THE UPPER-CAPE/. A CHALLENGE AND
A LOT OF UNCERTAINTY WITH RESPECT TO HEADLINES AND DECISION-MAKING.

EVALUATING LOW-LEVEL THERMAL PROFILES TOWARDS SNOW-TO-LIQUID RATIOS
DERIVED VIA A COBB-TECHNIQUE...WITH THE GREATEST LIFT OCCURRING
JUST BENEATH OR WITHIN THE DENDRITIC-GROWTH ZONE BASED ON A
CONSENSUS OF BUFKIT GFS PROFILES...ESPECIALLY IN HEAVIER- PRECIP
AREAS...BELIEVE THE SNOW WILL RANGE SOMEWHERE BETWEEN A WET AND
FLUFFY SNOW. SNOW PROPERTIES FROM FLUFFY TO WET LIKELY SIMILAR TO
THE N-S GRADIENT AS OUTLINED ABOVE.

4) HEADLINES...

HATE A WOBBLING FORECAST WHICH IS TYPICAL WITH SUCH SMALL EVENTS.
UNCERTAINTY DERIVES FROM LOW-LEVEL THERMAL PROFILES AND PRECIP
AMOUNTS. SURELY EXPECTING SNOW...BUT WITH ANY SHIFT N-S OF COLDER
AIR AND/OR PRECIPITATION AMOUNTS RESULTS IN AREAS SHIFTING FROM
ADVISORY TO WARNING...OR VICE VERSA. ENOUGH TO JUST PULL YOUR HAIR
OUT. THEN THERE IS THE TIMING OF THE SYSTEM THAT HAS SPED UP
SLIGHTLY. A SHORTER RESIDENCE TIME OF COURSE WOULD YIELD LESSER
SNOWFALL AMOUNTS. QUITE A CHALLENGING FORECAST RIGHT ON THE CUSP
OF HEADLINE THRESHOLDS.

THE EVENT DOES TAKE PLACE MAINLY FROM SUNDAY EVENING INTO THE EARLY
MORNING HOURS ON MONDAY DURING WHICH TIME THERE IS NOT MUCH TRAFFIC
ON THE ROAD. IS THIS A HIGH IMPACT EVENT THAT WARRANTS WARNINGS? A
QUESTION TO STRUGGLE WITH AS WARNINGS ARE NECESSARY WHEN WE ARE
CONFIDENT IN MEETING OR EXCEEDING 6+ INCH CRITERIA. YET THE QUESTION
IN FRONT OF US IS WHERE WILL THE HIGHER AMOUNTS OF SNOW FOCUS? HAVE
TO MAKE SOME SORT OF CALL...THE NEEDS OF THE MANY OUTWEIGH THE NEEDS
OF THE FEW.

ADVISORIES POSTED WHERE THERE IS HIGH CONFIDENCE OF SNOW BUT LIKELY
TO REMAIN BELOW THE 6-INCH THRESHOLD FOR WARNING. WATCHES CONTINUE
AND HAVE BEEN EXTENDED TO THE S-COAST TO COVER FOR THE UNCERTAINTY
OF THE AREA EITHER FALLING WITHIN OR IN EXCESS OF ADVISORY-LEVEL
SNOWS. AGAIN...6+ INCH AMOUNTS ARE ANTICIPATED BUT EXACTLY WHERE IS
UNCERTAIN.

5) CLOSING NOTES...

SOME CONCERN FOR THE EARLY MONDAY MORNING COMMUTE FOR E/SE MA AND
RI. WHILE MOST OF THE SNOW IS EXPECTED TO BE IMMEDIATELY OFFSHORE
WITH SUNRISE MONDAY...COMMUTERS COULD ENCOUNTER SLICK AND SLIPPERY
ROAD CONDITIONS. SNOW COULD POSSIBLY LINGER OVER SE MA SO THERE IS
THE POTENTIAL FOR REDUCED VISIBILITIES.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
BIG PICTURE... THE BROAD UPPER FLOW SHOWS A RIDGE IN THE EAST AND
TROUGH IN THE WEST WITH A WEST SOUTHWEST FLOW FROM THE PLAINS TO THE
EASTERN USA COAST. WITHIN THIS FLOW ARE BOTH NORTHERN AND SOUTHERN
STREAMS AT THE START OF THE WEEK. THE WESTERN TROUGH MIGRATES EAST
DURING THE MIDWEEK AT WHICH TIME THE TWO STREAMS MERGE TO FORM A 140-
160 KT UPPER JET FEEDING NORTHEAST INTO THE GREAT LAKES AND ST
LAWRENCE VALLEY. THIS JET LINGERS OVER OR NEAR NEW ENGLAND THURSDAY-
FRIDAY BEFORE MOVING OFF. THE WESTERN TROUGH MOVES ACROSS NEW
ENGLAND BY THE END OF THE WEEK.

DAILIES...

MONDAY... SUNDAY STORM MOVES OFF PAST NOVA SCOTIA WHILE THE
SUPPORTING UPPER SHORTWAVE AND COLD POOL SWING ACROSS NEW ENGLAND.
THE COOLEST AIR ALOFT IS IN NORTHERN NEW ENGLAND WHILE LEFTOVER
MOISTURE LINGERS BELOW 800 MB THROUGH THE DAY. THE GFS IS FASTER
THAN THE ECMWF IN BRINGING RISING PRESSURE TO THE REGION BUT HAVE 1
MB/HOUR RISES HERE BY EVENING. PUT TOGETHER...EXPECT A CLEARING
TREND BUT WITH LEFTOVER CLOUDS ESPECIALLY NORTH OF THE MASS PIKE.
SUSTAINED NORTHWEST WINDS SHOULD RISE TO 15-20 KTS. MIXING REACHES
TO AT LEAST 850 MB AND POSSIBLY A LITTLE HIGHER...WHICH SUPPORTS
GUSTS TO AT LEAST 30 KNOTS AND POSSIBLY 35 KNOTS. TEMPS AT 850 MB
WILL BE -11C TO -14C...MIXING THIS TO THE SURFACE WOULD SUPPORT MAX
SFC TEMPS IN THE 30S. MIN TEMPERATURES UPSTREAM THIS MORNING WERE IN
THE SINGLE NUMBERS WITH A FEW SPOTS BELOW ZERO. WITH LIGHT PRESSURE
GRADIENT ESP IN THE WEST...WE TENDED A FEW DEGREES COOLER THAN
CONSENSUS.

TUESDAY-WEDNESDAY... HIGH PRESSURE IN CONTROL MUCH OF TUESDAY BUT
MOVING OFFSHORE DURING THE AFTERNOON. CROSS SECTIONS SHOW INCREASING
MOISTURE AT MID AND HIGH CLOUD LEVEL...SO INCREASING HIGH CLOUDS.
SYSTEM MOVING INTO THE GREAT LAKES SPREADS PCPN INTO NEW YORK...BUT
WARM ADVECTION LIFT REMAINS MOSTLY TO OUR WEST THROUGH THE
AFTERNOON. SOME LIFT FORECAST AT 290K /ABOUT 730 MB AT THE TIME/ BUT
NONE BELOW THAT. MEANWHILE DEWPOINTS IN THE SINGLE NUMBERS PROGRESS
INTO THE TEENS DURING THE DAY...BUT ENOUGH OF A TEMP/DEWPOINT SPREAD
TO SLOW THE ADVANCE OF ANY PCPN FROM THE CLOUDS BY A FEW HOURS.

WARM ADVECTION LIFT MUCH OF THE NIGHT SUPPORTS THE IDEA OF PCPN.
TEMPERATURES START COLD DURING THE EVENING BUT SHOULD RISE
OVERNIGHT. THE QUESTION REMAINS AS TO HOW HIGH THEY WILL CLIMB. EVEN
WITH THE SURFACE SYSTEM TRACKING UP THE ST LAWRENCE VALLEY THERE IS
COLD GROUND AND A COLD SNOWPACK. THIS WOULD ALLOW THE WARMER TEMPS
TO SCREAM OVERHEAD WHILE THE IMMEDIATE SURFACE REMAINS SEVERAL
DEGREES COLDER. WE TRIMMED TEMPS BACK A LITTLE FROM MODEL
VALUES...BUT LOW CONFIDENCE AT THIS TIME DUE TO THE POTENTIAL THAT
SURFACE TEMPS COULD REMAIN IN THE 30S.

QPF FORECASTS RANGE FROM 0.50 TO 1.00 INCHES WITH THE HIGHER AMOUNTS
TENDING TOWARD THE SOUTH COAST. THIS POINTS TO A MESSY STORM WITH
INITIAL SNOW ACCUMS OF SEVERAL INCHES FOLLOWED BY A CHANGE TO
MEASURABLE ICE ACCUMULATION AND THEN A CHANGE TO RAIN WITH
POTENTIAL FOR POOR DRAINAGE FLOODING IN BETWEEN THE SNOW BANKS.

THE COLD FRONT SHOULD MOVE THROUGH DURING THE AFTERNOON/EVENING WITH
A SHIFT TO NORTHWEST WINDS. THIS WILL CHANGE THE PCPN BACK TO SNOW
BEFORE TAPERING OFF.

THURSDAY...DIFFERENCES IN THE GFS AND ECMWF IN HANDING THE UPPER JET.
THE ECMWF MOVES THE JET OFFSHORE AND PUTS SOUTHERN NEW ENGLAND
INTO SUBSIDENCE. THE GFS MAINTAINS THE JET OVERHEAD WITH OUR AREA
IN THE RIGHT ENTRANCE REGION. THE FIRST SCENARIO ENDS THE PCPN AND
COOLS THE AIR. THE SECOND SCENARIO WOULD SUPPORT LIFT AND GENERATE
WAVES ALONG THE DEPARTING COLD FRONT...MAINTAINING A CHANCE OF
SNOW OVER AT LEAST SOUTHERN PARTS OF OUR AREA. OUR THURSDAY
FORECAST TENDS TOWARD THE LATTER FOR NOW.

FRIDAY-SATURDAY... HIGH PRESSURE BUILDS OVER THE REGION THURSDAY
NIGHT AND FRIDAY WITH CLEARING SKIES AND A BRIEF PERIOD OF COLD AIR.
TEMPS ALOFT TREND UP ABOUT 10C ON SATURDAY SUGGESTING LESS CHILL AT
THE SURFACE. ANOTHER COLD FRONT APPROACHES THE ST LAWRENCE VALLEY
AND COULD SPREAD SOME CLOUDS INTO OUR AREA SATURDAY
AFTERNOON/EVENING. BUT PCPN CHANCES LOOK SMALL.

&&

.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /THROUGH MONDAY MORNING/...

TONIGHT THROUGH SUNDAY MIDDAY...HIGH CONFIDENCE.

VFR. LOWERING AND THICKENING CLOUDS SUNDAY MORNING INTO MIDDAY.

SUNDAY AFTERNOON INTO MONDAY MORNING...MODERATE CONFIDENCE.

SNOW OVERSPREADS THE REGION W-E. CIGS/VSBYS DETERIORATE TO MVFR-
IFR BY EARLY EVENING...WIDESPREAD IFR-LIFR SUNDAY NIGHT. SN TO MIX
WITH OR CHANGE TO FZRA ACROSS OFFSHORE ISLAND TERMINALS OVERNIGHT.
PRECIP ENDS W-E TOWARD DAYBREAK MONDAY....CONDITIONS IMPROVE.

KBOS TAF...MODERATE CONFIDENCE. TRENDS CERTAIN BUT NOT SO MUCH THE
ACTUAL TIMING OF IMPACTS.

KBDL TAF...MODERATE CONFIDENCE. TRENDS CERTAIN BUT NOT SO MUCH
THE ACTUAL TIMING OF IMPACTS.

OUTLOOK...MONDAY THROUGH THURSDAY...

MONDAY... HIGH CONFIDENCE. SOME IFR/MVFR IN SNOW EARLY MORNING BUT
OTHERWISE CONDITIONS WILL IMPROVE TO VFR DURING THE MORNING.
NORTHWEST WINDS WILL INCREASE WITH GUSTS AROUND 30 KNOTS BY MIDDAY.
VFR AND DIMINISHING WIND MONDAY NIGHT.

TUESDAY...MODERATE CONFIDENCE. VFR DURING THE DAY WITH INCREASING
SKY COVER. MVFR TUESDAY EVENING BECOMING IFR/LIFR OVERNIGHT IN
DEVELOPING SNOW AND FREEZING RAIN.

WEDNESDAY...MODERATE CONFIDENCE. IFR/LIFR IN RAIN AND FREEZING RAIN.

THURSDAY...LOW CONFIDENCE. VFR NORTH OF A HFD-BOS LINE. MVFR CIGS
AND AREAS OF MVFR/IFR VSBYS IN SNOW.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /THROUGH MONDAY MORNING/...HIGH CONFIDENCE.

HIGH PRESSURE NEARBY WILL KEEP WINDS/SEAS WELL BELOW SMALL CRAFT
ADVISORY THRESHOLDS INTO SUNDAY MORNING. A WEAK WAVE OF LOW
PRESSURE MOVES ACROSS THE WATERS LATE SUNDAY INTO SUNDAY NIGHT...
BUT WEAK PRESSURE GRADIENT SHOULD KEEP WINDS/SEAS BELOW SMALL
CRAFT THRESHOLDS.

OUTLOOK...MONDAY THROUGH THURSDAY..MODERATE CONFIDENCE.

MONDAY...WEST TO NORTHWEST WINDS INCREASE WITH FREQUENT GUSTS TO
GALE FORCE ESPECIALLY AWAY FROM THE NEARSHORE. THIS COULD GENERATE
SOME LIGHT FREEZING SPRAY ESPECIALLY EARLY MONDAY NIGHT. SEAS 5
TO 10 FEET. WINDS AND SEAS DIMINISH MONDAY NIGHT. A GALE WARNING
MAY BE NEEDED.

TUESDAY... LINGERING 5 FOOT SEAS ON THE OUTER WATERS BUT DIMINISHING
DURING THE MORNING.  WINDS AND SEAS INCREASE AGAIN TUESDAY NIGHT
AFTER MIDNIGHT AHEAD OF A GREAT LAKES COLD FRONT. SOUTH WINDS WILL
APPROACH 25 KNOTS WITH SEAS BUILDING TO 5 TO 8 FEET. VSBYS WILL
BE REDUCED IN SNOW CHANGING TO RAIN.

WEDNESDAY...SOUTHWEST WINDS WITH GUSTS 25-30 KNOTS.  SEAS BUILDING
TO 6 TO 12 FEET. REDUCED VSBYS IN RAIN. A SMALL CRAFT ADVISORY MAY
BE NEEDED.

THURSDAY...NORTHWEST WINDS WILL GUST TO 25 KNOTS...AND SEAS 5 TO 8
FEET. BOTH SHOULD DIMINISH TOWARD EVENING.  A SMALL CRAFT ADVISORY
MAY BE NEEDED.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY
     MORNING FOR CTZ002>004.
MA...WINTER WEATHER ADVISORY FROM NOON SUNDAY TO 7 AM EST MONDAY
     FOR MAZ002>008-010-014-023-024-026.
     WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY
     MORNING FOR MAZ009-011>013-015>022.
RI...WINTER WEATHER ADVISORY FROM NOON SUNDAY TO 7 AM EST MONDAY
     FOR RIZ008.
     WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY
     MORNING FOR RIZ001>007.
MARINE...NONE.

&&

$$
SYNOPSIS...WTB/SIPPRELL
NEAR TERM...FRANK
SHORT TERM...SIPPRELL
LONG TERM...WTB
AVIATION...WTB/SIPPRELL
MARINE...WTB/SIPPRELL



000
FXUS61 KBOX 010217
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
917 PM EST SAT FEB 28 2015

.SYNOPSIS...

A FAST MOVING LOW PRESSURE SYSTEM WILL BRING ACCUMULATING SNOW TO
THE REGION LATE SUNDAY INTO SUNDAY NIGHT...WITH THE HIGHEST AMOUNTS
EXPECTED SOUTH OF THE MASSACHUSETTS TURNPIKE AND AWAY FROM THE
IMMEDIATE SOUTH COAST. HIGH PRESSURE BRINGS DRY COLD AIR FOR THE
EARLY WEEK. LOW PRESSURE FROM NORTHERN CANADA AND ASSOCIATED LOW
FORMING OVER THE PLAINS MONDAY WILL MERGE...THEN PASS WEST AND
NORTH OF NEW ENGLAND. THIS WILL SWING A COLD FRONT ACROSS THE
REGION ON WEDNESDAY. DRY AND COLD WEATHER RETURNS FOR THE END OF
THE WEEK.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...

915 PM UPDATE...

CLEAR SKIES...LIGHT WINDS AND DEEP SNOW PACK WERE RESULTING IN
ANOTHER EXCELLENT NIGHT OF RADIATIONAL COOLING THIS EVENING WITH A
WIDE RANGE IN TEMPERATURES.  LOW TEMPS WILL BOTTOM OUT BETWEEN 5 AND
10 BELOW ZERO ACROSS THE NORMALLY COLDEST OUTLYING LOCATIONS.  OTHER
AREAS THAT DO NOT RADIATE AS WELL SUCH AS THE HIGHER TERRAIN/URBAN
CENTERS WILL SEE LOWS MAINLY IN THE SINGLE DIGITS...TO LOWER TEENS.

THESE LOW TEMPS WILL LIKELY OCCUR A FEW HOURS BEFORE SUNRISE AND
THEN LEVEL OFF OR RISE BY DAYBREAK AS SOME MID/HIGH LEVEL CLOUDINESS
MOVES IN FROM THE WEST.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
*/ SUNDAY MORNING INTO MIDDAY...

QUIET WEATHER. CLOUDS THICKENING AS WINDS INCREASE OUT OF THE S.
WILL SEE TEMPERATURES GRADUALLY MODERATE INTO THE MID- TO UPPER-20S.

*/ SUNDAY AFTERNOON INTO EARLY MONDAY MORNING...

1) HIGHLIGHTS...

 - SNOW SUNDAY AFTERNOON INTO MONDAY MORNING
 - GREATEST INTENSITY SUNDAY EVENING AND OVERNIGHT
 - 6+ INCH SNOWFALLS EXPECTED BUT EXACTLY WHERE REMAINS UNCERTAIN
 - ANNOYINGLY...FORECAST GUIDANCE CONTINUES TO WOBBLE

1) OVERVIEW...

BROAD ISENTROPIC OVER-RUNNING EVENT OF GULF MOISTURE ALONG THE 275-
295K SURFACES AMPLIFIED BY A N-STREAM IMPULSE DURING THE TIMEFRAME
POSSIBLY INVOKING AN AREA OF LOW PRESSURE THAT SKIRTS ALONG THE S-
COAST SUBSEQUENTLY ENHANCING LOW-LEVEL WIND PROFILE. LIGHT-MODERATE
SNOWFALL IS ANTICIPATED WITH LOCALLY HEAVIER AMOUNTS. THE INTENSE
PORTION OF SNOWFALL IS EXPECTED SUNDAY EVENING AND OVERNIGHT ENDING
EARLY MONDAY MORNING.

MODEL PREFERENCE GIVEN TO THE ECMWF/GFS/REGIONAL CANADIAN WHICH WILL
SERVE AS THE CONSENSUS OF GUIDANCE FOR THIS DISCUSSION. THE 28.12Z
NAM WAS CONSIDERED AN OUTLIER WITH ITS AGGRESSIVE-MODE AND SECONDARY
LOW DEVELOPMENT JUST OFFSHORE.

2) PRECIPITATION-TYPE...

EVALUATING THERMAL FIELDS...BLEND OF FORECAST CONSENSUS PUTS THE
-2C H925 ISOTHERM W-E ACROSS S-TIER OF CT/RI AND ACROSS SE MA WITH
THE 0C H85 ISOTHERM JUST S OF LONG-ISLAND AND NANTUCKET COASTLINES.
THE CONSENSUS OF 1000-850 MB CRITICAL THICKNESSES LAYS RIGHT ALONG
THE IMMEDIATE S-COAST OF LONG-ISLAND AND CAPE COD.

AN ALL SNOW-EVENT WHEN CONSIDERING DYNAMIC-COOLING/WETBULBING OF THE
LOW-LEVELS AHEAD OF THE EVENT. THERE IS PERHAPS A CHANCE OF A BRIEF
MIX-OVER TO RAIN/FREEZING RAIN ACROSS THE CAPE AND ISLANDS AS S-FLOW
AT THE SURFACE IS POSSIBLY ABLE TO NUDGE ABOVE-FREEZING TEMPERATURES
N. YET AS WE ARE IN A FROZEN TUNDRA...WITH ANY RAIN IT WOULD LIKELY
FREEZE ON SURFACES WHICH ARE QUITE COLD. THUS FREEZING RAIN PREVAILS
OVER RAIN IN THE FORECAST.

3) SNOWFALL...

FORECAST CONSENSUS OF A 0.3-0.6 N-S PRECIPITATION EVENT WITH A N-S
SNOW-TO-LIQUID RATIO GRADIENT RANGING FROM 15:1 TO 10:1 YIELDS HIGH-
END SNOW ADVISORY CRITERIA WITH SNOWFALL AMOUNTS RANGING ON AVERAGE
AROUND 3-6 INCHES. AREAS OF 6+ INCHES ARE EXPECTED...ESPECIALLY FROM
CENTRAL-CT E INTO SE-MA /INCLUDING THE UPPER-CAPE/. A CHALLENGE AND
A LOT OF UNCERTAINTY WITH RESPECT TO HEADLINES AND DECISION-MAKING.

EVALUATING LOW-LEVEL THERMAL PROFILES TOWARDS SNOW-TO-LIQUID RATIOS
DERIVED VIA A COBB-TECHNIQUE...WITH THE GREATEST LIFT OCCURRING
JUST BENEATH OR WITHIN THE DENDRITIC-GROWTH ZONE BASED ON A
CONSENSUS OF BUFKIT GFS PROFILES...ESPECIALLY IN HEAVIER- PRECIP
AREAS...BELIEVE THE SNOW WILL RANGE SOMEWHERE BETWEEN A WET AND
FLUFFY SNOW. SNOW PROPERTIES FROM FLUFFY TO WET LIKELY SIMILAR TO
THE N-S GRADIENT AS OUTLINED ABOVE.

4) HEADLINES...

HATE A WOBBLING FORECAST WHICH IS TYPICAL WITH SUCH SMALL EVENTS.
UNCERTAINTY DERIVES FROM LOW-LEVEL THERMAL PROFILES AND PRECIP
AMOUNTS. SURELY EXPECTING SNOW...BUT WITH ANY SHIFT N-S OF COLDER
AIR AND/OR PRECIPITATION AMOUNTS RESULTS IN AREAS SHIFTING FROM
ADVISORY TO WARNING...OR VICE VERSA. ENOUGH TO JUST PULL YOUR HAIR
OUT. THEN THERE IS THE TIMING OF THE SYSTEM THAT HAS SPED UP
SLIGHTLY. A SHORTER RESIDENCE TIME OF COURSE WOULD YIELD LESSER
SNOWFALL AMOUNTS. QUITE A CHALLENGING FORECAST RIGHT ON THE CUSP
OF HEADLINE THRESHOLDS.

THE EVENT DOES TAKE PLACE MAINLY FROM SUNDAY EVENING INTO THE EARLY
MORNING HOURS ON MONDAY DURING WHICH TIME THERE IS NOT MUCH TRAFFIC
ON THE ROAD. IS THIS A HIGH IMPACT EVENT THAT WARRANTS WARNINGS? A
QUESTION TO STRUGGLE WITH AS WARNINGS ARE NECESSARY WHEN WE ARE
CONFIDENT IN MEETING OR EXCEEDING 6+ INCH CRITERIA. YET THE QUESTION
IN FRONT OF US IS WHERE WILL THE HIGHER AMOUNTS OF SNOW FOCUS? HAVE
TO MAKE SOME SORT OF CALL...THE NEEDS OF THE MANY OUTWEIGH THE NEEDS
OF THE FEW.

ADVISORIES POSTED WHERE THERE IS HIGH CONFIDENCE OF SNOW BUT LIKELY
TO REMAIN BELOW THE 6-INCH THRESHOLD FOR WARNING. WATCHES CONTINUE
AND HAVE BEEN EXTENDED TO THE S-COAST TO COVER FOR THE UNCERTAINTY
OF THE AREA EITHER FALLING WITHIN OR IN EXCESS OF ADVISORY-LEVEL
SNOWS. AGAIN...6+ INCH AMOUNTS ARE ANTICIPATED BUT EXACTLY WHERE IS
UNCERTAIN.

5) CLOSING NOTES...

SOME CONCERN FOR THE EARLY MONDAY MORNING COMMUTE FOR E/SE MA AND
RI. WHILE MOST OF THE SNOW IS EXPECTED TO BE IMMEDIATELY OFFSHORE
WITH SUNRISE MONDAY...COMMUTERS COULD ENCOUNTER SLICK AND SLIPPERY
ROAD CONDITIONS. SNOW COULD POSSIBLY LINGER OVER SE MA SO THERE IS
THE POTENTIAL FOR REDUCED VISIBILITIES.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
BIG PICTURE... THE BROAD UPPER FLOW SHOWS A RIDGE IN THE EAST AND
TROUGH IN THE WEST WITH A WEST SOUTHWEST FLOW FROM THE PLAINS TO THE
EASTERN USA COAST. WITHIN THIS FLOW ARE BOTH NORTHERN AND SOUTHERN
STREAMS AT THE START OF THE WEEK. THE WESTERN TROUGH MIGRATES EAST
DURING THE MIDWEEK AT WHICH TIME THE TWO STREAMS MERGE TO FORM A 140-
160 KT UPPER JET FEEDING NORTHEAST INTO THE GREAT LAKES AND ST
LAWRENCE VALLEY. THIS JET LINGERS OVER OR NEAR NEW ENGLAND THURSDAY-
FRIDAY BEFORE MOVING OFF. THE WESTERN TROUGH MOVES ACROSS NEW
ENGLAND BY THE END OF THE WEEK.

DAILIES...

MONDAY... SUNDAY STORM MOVES OFF PAST NOVA SCOTIA WHILE THE
SUPPORTING UPPER SHORTWAVE AND COLD POOL SWING ACROSS NEW ENGLAND.
THE COOLEST AIR ALOFT IS IN NORTHERN NEW ENGLAND WHILE LEFTOVER
MOISTURE LINGERS BELOW 800 MB THROUGH THE DAY. THE GFS IS FASTER
THAN THE ECMWF IN BRINGING RISING PRESSURE TO THE REGION BUT HAVE 1
MB/HOUR RISES HERE BY EVENING. PUT TOGETHER...EXPECT A CLEARING
TREND BUT WITH LEFTOVER CLOUDS ESPECIALLY NORTH OF THE MASS PIKE.
SUSTAINED NORTHWEST WINDS SHOULD RISE TO 15-20 KTS. MIXING REACHES
TO AT LEAST 850 MB AND POSSIBLY A LITTLE HIGHER...WHICH SUPPORTS
GUSTS TO AT LEAST 30 KNOTS AND POSSIBLY 35 KNOTS. TEMPS AT 850 MB
WILL BE -11C TO -14C...MIXING THIS TO THE SURFACE WOULD SUPPORT MAX
SFC TEMPS IN THE 30S. MIN TEMPERATURES UPSTREAM THIS MORNING WERE IN
THE SINGLE NUMBERS WITH A FEW SPOTS BELOW ZERO. WITH LIGHT PRESSURE
GRADIENT ESP IN THE WEST...WE TENDED A FEW DEGREES COOLER THAN
CONSENSUS.

TUESDAY-WEDNESDAY... HIGH PRESSURE IN CONTROL MUCH OF TUESDAY BUT
MOVING OFFSHORE DURING THE AFTERNOON. CROSS SECTIONS SHOW INCREASING
MOISTURE AT MID AND HIGH CLOUD LEVEL...SO INCREASING HIGH CLOUDS.
SYSTEM MOVING INTO THE GREAT LAKES SPREADS PCPN INTO NEW YORK...BUT
WARM ADVECTION LIFT REMAINS MOSTLY TO OUR WEST THROUGH THE
AFTERNOON. SOME LIFT FORECAST AT 290K /ABOUT 730 MB AT THE TIME/ BUT
NONE BELOW THAT. MEANWHILE DEWPOINTS IN THE SINGLE NUMBERS PROGRESS
INTO THE TEENS DURING THE DAY...BUT ENOUGH OF A TEMP/DEWPOINT SPREAD
TO SLOW THE ADVANCE OF ANY PCPN FROM THE CLOUDS BY A FEW HOURS.

WARM ADVECTION LIFT MUCH OF THE NIGHT SUPPORTS THE IDEA OF PCPN.
TEMPERATURES START COLD DURING THE EVENING BUT SHOULD RISE
OVERNIGHT. THE QUESTION REMAINS AS TO HOW HIGH THEY WILL CLIMB. EVEN
WITH THE SURFACE SYSTEM TRACKING UP THE ST LAWRENCE VALLEY THERE IS
COLD GROUND AND A COLD SNOWPACK. THIS WOULD ALLOW THE WARMER TEMPS
TO SCREAM OVERHEAD WHILE THE IMMEDIATE SURFACE REMAINS SEVERAL
DEGREES COLDER. WE TRIMMED TEMPS BACK A LITTLE FROM MODEL
VALUES...BUT LOW CONFIDENCE AT THIS TIME DUE TO THE POTENTIAL THAT
SURFACE TEMPS COULD REMAIN IN THE 30S.

QPF FORECASTS RANGE FROM 0.50 TO 1.00 INCHES WITH THE HIGHER AMOUNTS
TENDING TOWARD THE SOUTH COAST. THIS POINTS TO A MESSY STORM WITH
INITIAL SNOW ACCUMS OF SEVERAL INCHES FOLLOWED BY A CHANGE TO
MEASURABLE ICE ACCUMULATION AND THEN A CHANGE TO RAIN WITH
POTENTIAL FOR POOR DRAINAGE FLOODING IN BETWEEN THE SNOW BANKS.

THE COLD FRONT SHOULD MOVE THROUGH DURING THE AFTERNOON/EVENING WITH
A SHIFT TO NORTHWEST WINDS. THIS WILL CHANGE THE PCPN BACK TO SNOW
BEFORE TAPERING OFF.

THURSDAY...DIFFERENCES IN THE GFS AND ECMWF IN HANDING THE UPPER JET.
THE ECMWF MOVES THE JET OFFSHORE AND PUTS SOUTHERN NEW ENGLAND
INTO SUBSIDENCE. THE GFS MAINTAINS THE JET OVERHEAD WITH OUR AREA
IN THE RIGHT ENTRANCE REGION. THE FIRST SCENARIO ENDS THE PCPN AND
COOLS THE AIR. THE SECOND SCENARIO WOULD SUPPORT LIFT AND GENERATE
WAVES ALONG THE DEPARTING COLD FRONT...MAINTAINING A CHANCE OF
SNOW OVER AT LEAST SOUTHERN PARTS OF OUR AREA. OUR THURSDAY
FORECAST TENDS TOWARD THE LATTER FOR NOW.

FRIDAY-SATURDAY... HIGH PRESSURE BUILDS OVER THE REGION THURSDAY
NIGHT AND FRIDAY WITH CLEARING SKIES AND A BRIEF PERIOD OF COLD AIR.
TEMPS ALOFT TREND UP ABOUT 10C ON SATURDAY SUGGESTING LESS CHILL AT
THE SURFACE. ANOTHER COLD FRONT APPROACHES THE ST LAWRENCE VALLEY
AND COULD SPREAD SOME CLOUDS INTO OUR AREA SATURDAY
AFTERNOON/EVENING. BUT PCPN CHANCES LOOK SMALL.

&&

.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /THROUGH MONDAY MORNING/...

TONIGHT THROUGH SUNDAY MIDDAY...HIGH CONFIDENCE.

VFR. LOWERING AND THICKENING CLOUDS SUNDAY MORNING INTO MIDDAY.

SUNDAY AFTERNOON INTO MONDAY MORNING...MODERATE CONFIDENCE.

SNOW OVERSPREADS THE REGION W-E. CIGS/VSBYS DETERIORATE TO MVFR-
IFR BY EARLY EVENING...WIDESPREAD IFR-LIFR SUNDAY NIGHT. SN TO MIX
WITH OR CHANGE TO FZRA ACROSS OFFSHORE ISLAND TERMINALS OVERNIGHT.
PRECIP ENDS W-E TOWARD DAYBREAK MONDAY....CONDITIONS IMPROVE.

KBOS TAF...MODERATE CONFIDENCE. TRENDS CERTAIN BUT NOT SO MUCH THE
ACTUAL TIMING OF IMPACTS.

KBDL TAF...MODERATE CONFIDENCE. TRENDS CERTAIN BUT NOT SO MUCH
THE ACTUAL TIMING OF IMPACTS.

OUTLOOK...MONDAY THROUGH THURSDAY...

MONDAY... HIGH CONFIDENCE. SOME IFR/MVFR IN SNOW EARLY MORNING BUT
OTHERWISE CONDITIONS WILL IMPROVE TO VFR DURING THE MORNING.
NORTHWEST WINDS WILL INCREASE WITH GUSTS AROUND 30 KNOTS BY MIDDAY.
VFR AND DIMINISHING WIND MONDAY NIGHT.

TUESDAY...MODERATE CONFIDENCE. VFR DURING THE DAY WITH INCREASING
SKY COVER. MVFR TUESDAY EVENING BECOMING IFR/LIFR OVERNIGHT IN
DEVELOPING SNOW AND FREEZING RAIN.

WEDNESDAY...MODERATE CONFIDENCE. IFR/LIFR IN RAIN AND FREEZING RAIN.

THURSDAY...LOW CONFIDENCE. VFR NORTH OF A HFD-BOS LINE. MVFR CIGS
AND AREAS OF MVFR/IFR VSBYS IN SNOW.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /THROUGH MONDAY MORNING/...HIGH CONFIDENCE.

HIGH PRESSURE NEARBY WILL KEEP WINDS/SEAS WELL BELOW SMALL CRAFT
ADVISORY THRESHOLDS INTO SUNDAY MORNING. A WEAK WAVE OF LOW
PRESSURE MOVES ACROSS THE WATERS LATE SUNDAY INTO SUNDAY NIGHT...
BUT WEAK PRESSURE GRADIENT SHOULD KEEP WINDS/SEAS BELOW SMALL
CRAFT THRESHOLDS.

OUTLOOK...MONDAY THROUGH THURSDAY..MODERATE CONFIDENCE.

MONDAY...WEST TO NORTHWEST WINDS INCREASE WITH FREQUENT GUSTS TO
GALE FORCE ESPECIALLY AWAY FROM THE NEARSHORE. THIS COULD GENERATE
SOME LIGHT FREEZING SPRAY ESPECIALLY EARLY MONDAY NIGHT. SEAS 5
TO 10 FEET. WINDS AND SEAS DIMINISH MONDAY NIGHT. A GALE WARNING
MAY BE NEEDED.

TUESDAY... LINGERING 5 FOOT SEAS ON THE OUTER WATERS BUT DIMINISHING
DURING THE MORNING.  WINDS AND SEAS INCREASE AGAIN TUESDAY NIGHT
AFTER MIDNIGHT AHEAD OF A GREAT LAKES COLD FRONT. SOUTH WINDS WILL
APPROACH 25 KNOTS WITH SEAS BUILDING TO 5 TO 8 FEET. VSBYS WILL
BE REDUCED IN SNOW CHANGING TO RAIN.

WEDNESDAY...SOUTHWEST WINDS WITH GUSTS 25-30 KNOTS.  SEAS BUILDING
TO 6 TO 12 FEET. REDUCED VSBYS IN RAIN. A SMALL CRAFT ADVISORY MAY
BE NEEDED.

THURSDAY...NORTHWEST WINDS WILL GUST TO 25 KNOTS...AND SEAS 5 TO 8
FEET. BOTH SHOULD DIMINISH TOWARD EVENING.  A SMALL CRAFT ADVISORY
MAY BE NEEDED.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY
     MORNING FOR CTZ002>004.
MA...WINTER WEATHER ADVISORY FROM NOON SUNDAY TO 7 AM EST MONDAY
     FOR MAZ002>008-010-014-023-024-026.
     WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY
     MORNING FOR MAZ009-011>013-015>022.
RI...WINTER WEATHER ADVISORY FROM NOON SUNDAY TO 7 AM EST MONDAY
     FOR RIZ008.
     WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY
     MORNING FOR RIZ001>007.
MARINE...NONE.

&&

$$
SYNOPSIS...WTB/SIPPRELL
NEAR TERM...FRANK
SHORT TERM...SIPPRELL
LONG TERM...WTB
AVIATION...WTB/SIPPRELL
MARINE...WTB/SIPPRELL



000
FXUS61 KGYX 010028
AFDGYX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
728 PM EST SAT FEB 28 2015

.SYNOPSIS...
HIGH PRESSURE WILL CREST OVER THE REGION THIS EVENING BEFORE
SHIFTING OFFSHORE SUNDAY. WEAK LOW PRESSURE CROSSES THE REGION
SUNDAY NIGHT...PRODUCING SOME ACCUMULATING SNOW...BEFORE MOVING
INTO THE CANADIAN MARITIMES ON MONDAY. HIGH PRESSURE CROSSES THE
AREA MONDAY NIGHT AND TUESDAY. LOW PRESSURE WILL MOVE OUT OF THE
GREAT LAKES TUESDAY NIGHT AND WILL TRACK NORTHEAST THROUGH THE ST
LAWRENCE VALLEY ON WEDNESDAY...BRINGING A ROUND OF MIXED
PRECIPITATION TO THE AREA. A COLD FRONT FOLLOWS WEDNESDAY NIGHT.
HIGH PRESSURE BUILDS IN FOR THE END OF THE WEEK.

&&

.NEAR TERM /TONIGHT/...
730PM UPDATE...
HAVE UPDATED OVERNIGHT TEMPERATURE FORECAST TO LOWER FORECAST
VALUES BY A FEW DEGREES PRIMARILY IN KNOWN COLD SPOTS AND ACROSS
SOUTHWEST NEW HAMPSHIRE. ALTHOUGH WINDS ARE MORE CALM TONIGHT THAN
LAST NIGHT... THERE ARE A FEW FACTORS WHICH GIVE REASON TO BELIEVE
WE WILL GENERALLY NOT FALL AS LOW TONIGHT AS LAST NIGHT. THE FIRST
IS THAT DEWPOINT VALUES ARE 5 TO 10 DEGREES WARMER THIS EVENING
THAN YESTERDAY EVENING... THOUGH ADMITTEDLY THESE ARE STILL
GENERALLY AROUND OR BELOW ZERO. AT THIS LEVEL OF DRYNESS IT DOES
NOT TAKE MUCH TO DIG BENEATH CURRENT DEWPOINTS ONCE COOLING
MAXIMIZES ESPECIALLY IN LOCAL VALLEYS. ANOTHER FACTOR IS AFTERNOON
TEMPERATURES STARTED OFF WARMER TODAY... MEANING TEMPERATURES HAVE
FURTHER TO FALL TONIGHT TO REACH THE SAME LEVELS. ONE FINAL FACTOR
IS THE EXPECTED EVENTUAL ARRIVAL OF SOME CIRRUS CLOUDS IN ADVANCE
OF THE APPROACHING SYSTEM BY MORNING. THIS COULD LIMIT COOLING
JUST BEFORE DAWN BY JUST A BIT. EVEN WITH ALL THESE LIMITATIONS...
STILL EXPECT A GOOD CHUNK OF THE AREA TO FALL BELOW ZERO AGAIN.
SHOULD MAKE A DECENT RUN AT ZERO IN PORTLAND AS WELL.

PRECIPITATION CHANCES WERE UPDATED AS WELL TO FURTHER CLARIFY WHEN
PRECIPITATION SHOULD BEGIN AND END ACROSS THE AREA NOT JUST
TONIGHT (NO PRECIPITATION TONIGHT) BUT ALSO TOMORROW AND SUNDAY
NIGHT WHEN CONFIDENCE IS HIGH THAT COASTAL AREAS WILL SEE SOME
MINOR ACCUMULATIONS.

ORIGINAL DISCUSSION...
THE COLDEST MONTH EVER FOR PORTLAND MAINE WILL BE IN THE BOOKS
SHORTLY. LAST NIGHT WAS NEAR RECORD COLD AS WELL...WITH A LOW OF
MINUS 7 IN THE FOREST CITY. THIS IS JUST SHY OF THE RECORD LOW OF
MINUS 9 SET BACK IN 1950.

WITH CLEAR SKIES AND LIGHT WINDS...EXPECT RADIATIONAL COOLING ONCE
AGAIN TONIGHT. WILL FORECAST ON THE LOWER END OF THE 12Z MODEL
SUITE WITH READINGS APPROACHING ZERO NEAR THE COASTLINE AND BELOW
ZERO OVER INTERIOR LOCATIONS. HIGH CLOUDS WILL BE ARRIVING LATER
TONIGHT. THIS MAY KEEP READINGS FROM TRULY BOTTOMING OUT AS WAS
THE CASE LAST NIGHT.

&&

.SHORT TERM /SUNDAY AND SUNDAY NIGHT/...
A BROAD AND WEAK AREA OF WARM AIR ADVECTION WILL ALLOW CLOUDS TO
THICKEN ON SUNDAY ACROSS THE FORECAST AREA. LIGHT SNOW WILL BREAK
OUT SUNDAY NIGHT AS THIS DEVELOPING MOISTURE INTERACTS WITH AN
APPROACHING UPPER LEVEL TROUGH.

SURFACE LOW PRESSURE WILL FORM IN THE GULF OF MAINE LATE SUNDAY
NIGHT...BUT LIKELY TOO LATE TO BRING APPRECIABLE MOISTURE AND
SNOWFALL TO THE REGION. NEVERTHELESS...THERE WILL BE TWO TO AS
MUCH AS FOUR INCHES OF SNOW OVER SOUTHERNMOST PORTIONS OF THE
FORECAST AREA. FURTHER TO THE NORTH...AS HAS BEEN THE CASE MUCH OF
THIS WINTER...LESS SNOW WILL FALL.

TEMPERATURES WILL BE MODERATING BUT STILL BELOW NORMAL FOR THIS
TIME OF THE YEAR.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
A SURFACE LOW EXITS RAPIDLY EAST INTO THE MARITIMES MONDAY WHILE
THE UPPER TROF MOVES THROUGH NORTHERN NEW ENGLAND. THE
PRECIPITATION WILL QUICKLY COME TO AN END EARLY MONDAY AS
DOWNSLOPING NORTHWEST WINDS KICK IN. HIGH PRESSURE BUILDS INTO THE
AREA MONDAY NIGHT AND TUESDAY. A FAST MOVING SHORT WAVE WITH
ASSOCIATED WARM AIR ADVECTION OVERRUNNING PRECIPITATION WILL MOVE
INTO THE AREA TUESDAY NIGHT IN THE FORM OF SNOW. SEVERAL INCHES OF
SNOW IS EXPECTED THROUGHOUT THE AREA. BY WEDNESDAY MORNING A BRIEF
CHANGEOVER TO A MIX OF RAIN OR SNOW SHOWERS OVER SOUTHERN AREAS IS
POSSIBLE BEFORE THE PRECIPITATION ENDS AS LOW AND MID LEVEL
TEMPERATURES MAY WARM ABOVE CRITICAL LEVELS. BY LATE WEDNESDAY
MORNING A COLD FRONT MOVES ACROSS THE AREA AND THEN OFFSHORE WITH
CLEARING BEHIND THE FRONT. HIGH PRESSURE BUILDS INTO THE REGION
FOR THURSDAY AND FRIDAY WITH FAIR CONDITIONS.

TEMPERATURES WILL GENERALLY REMAIN BELOW NORMAL FOR THE WEEK. USED
A BLEND OF THE MODELS FOR TEMPERATURES AND POPS.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
SHORT TERM...VFR CONDITIONS DETERIORATING TO MVFR AND IFR SUNDAY
NIGHT IN LIGHT SNOW.

LONG TERM...
MVFR TO IFR CONDITIONS EARLY MONDAY WILL IMPROVE TO VFR BY LATE
MORNING MONDAY AND CONTINUE THROUGH TUESDAY. TUESDAY NIGHT MVFR TO
IFR CONDITIONS WILL DEVELOP AND CONTINUE INTO WEDNESDAY MORNING.
CONDITIONS WILL RETURN TO VFR BY WEDNESDAY AFTERNOON AND CONTINUE
THROUGH FRIDAY.

&&

.MARINE...
SHORT TERM...NO FLAGS. WINDS BELOW SCA THRESHOLDS AS WELL AS SEAS
IN THE SHORT TERM PORTION OF THE FORECAST.

LONG TERM...EXPECT TO NEED A STRONG SCA MONDAY AFTERNOON INTO
MONDAY NIGHT IN AN INCREASING WEST FLOW...WINDS DIMINISH LATE
MONDAY NIGHT. SCA MAY BE NEEDED AGAIN IN A SOUTH TO SOUTHWEST
FLOW LATE TUESDAY NIGHT AND WEDNESDAY.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.

&&

$$

NEAR TERM UPDATE...KIMBLE
SHORT TERM...CANNON
LONG TERM...MARINE
AVIATION...CANNON/MARINE
MARINE...CANNON/MARINE



000
FXUS61 KGYX 010028
AFDGYX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
728 PM EST SAT FEB 28 2015

.SYNOPSIS...
HIGH PRESSURE WILL CREST OVER THE REGION THIS EVENING BEFORE
SHIFTING OFFSHORE SUNDAY. WEAK LOW PRESSURE CROSSES THE REGION
SUNDAY NIGHT...PRODUCING SOME ACCUMULATING SNOW...BEFORE MOVING
INTO THE CANADIAN MARITIMES ON MONDAY. HIGH PRESSURE CROSSES THE
AREA MONDAY NIGHT AND TUESDAY. LOW PRESSURE WILL MOVE OUT OF THE
GREAT LAKES TUESDAY NIGHT AND WILL TRACK NORTHEAST THROUGH THE ST
LAWRENCE VALLEY ON WEDNESDAY...BRINGING A ROUND OF MIXED
PRECIPITATION TO THE AREA. A COLD FRONT FOLLOWS WEDNESDAY NIGHT.
HIGH PRESSURE BUILDS IN FOR THE END OF THE WEEK.

&&

.NEAR TERM /TONIGHT/...
730PM UPDATE...
HAVE UPDATED OVERNIGHT TEMPERATURE FORECAST TO LOWER FORECAST
VALUES BY A FEW DEGREES PRIMARILY IN KNOWN COLD SPOTS AND ACROSS
SOUTHWEST NEW HAMPSHIRE. ALTHOUGH WINDS ARE MORE CALM TONIGHT THAN
LAST NIGHT... THERE ARE A FEW FACTORS WHICH GIVE REASON TO BELIEVE
WE WILL GENERALLY NOT FALL AS LOW TONIGHT AS LAST NIGHT. THE FIRST
IS THAT DEWPOINT VALUES ARE 5 TO 10 DEGREES WARMER THIS EVENING
THAN YESTERDAY EVENING... THOUGH ADMITTEDLY THESE ARE STILL
GENERALLY AROUND OR BELOW ZERO. AT THIS LEVEL OF DRYNESS IT DOES
NOT TAKE MUCH TO DIG BENEATH CURRENT DEWPOINTS ONCE COOLING
MAXIMIZES ESPECIALLY IN LOCAL VALLEYS. ANOTHER FACTOR IS AFTERNOON
TEMPERATURES STARTED OFF WARMER TODAY... MEANING TEMPERATURES HAVE
FURTHER TO FALL TONIGHT TO REACH THE SAME LEVELS. ONE FINAL FACTOR
IS THE EXPECTED EVENTUAL ARRIVAL OF SOME CIRRUS CLOUDS IN ADVANCE
OF THE APPROACHING SYSTEM BY MORNING. THIS COULD LIMIT COOLING
JUST BEFORE DAWN BY JUST A BIT. EVEN WITH ALL THESE LIMITATIONS...
STILL EXPECT A GOOD CHUNK OF THE AREA TO FALL BELOW ZERO AGAIN.
SHOULD MAKE A DECENT RUN AT ZERO IN PORTLAND AS WELL.

PRECIPITATION CHANCES WERE UPDATED AS WELL TO FURTHER CLARIFY WHEN
PRECIPITATION SHOULD BEGIN AND END ACROSS THE AREA NOT JUST
TONIGHT (NO PRECIPITATION TONIGHT) BUT ALSO TOMORROW AND SUNDAY
NIGHT WHEN CONFIDENCE IS HIGH THAT COASTAL AREAS WILL SEE SOME
MINOR ACCUMULATIONS.

ORIGINAL DISCUSSION...
THE COLDEST MONTH EVER FOR PORTLAND MAINE WILL BE IN THE BOOKS
SHORTLY. LAST NIGHT WAS NEAR RECORD COLD AS WELL...WITH A LOW OF
MINUS 7 IN THE FOREST CITY. THIS IS JUST SHY OF THE RECORD LOW OF
MINUS 9 SET BACK IN 1950.

WITH CLEAR SKIES AND LIGHT WINDS...EXPECT RADIATIONAL COOLING ONCE
AGAIN TONIGHT. WILL FORECAST ON THE LOWER END OF THE 12Z MODEL
SUITE WITH READINGS APPROACHING ZERO NEAR THE COASTLINE AND BELOW
ZERO OVER INTERIOR LOCATIONS. HIGH CLOUDS WILL BE ARRIVING LATER
TONIGHT. THIS MAY KEEP READINGS FROM TRULY BOTTOMING OUT AS WAS
THE CASE LAST NIGHT.

&&

.SHORT TERM /SUNDAY AND SUNDAY NIGHT/...
A BROAD AND WEAK AREA OF WARM AIR ADVECTION WILL ALLOW CLOUDS TO
THICKEN ON SUNDAY ACROSS THE FORECAST AREA. LIGHT SNOW WILL BREAK
OUT SUNDAY NIGHT AS THIS DEVELOPING MOISTURE INTERACTS WITH AN
APPROACHING UPPER LEVEL TROUGH.

SURFACE LOW PRESSURE WILL FORM IN THE GULF OF MAINE LATE SUNDAY
NIGHT...BUT LIKELY TOO LATE TO BRING APPRECIABLE MOISTURE AND
SNOWFALL TO THE REGION. NEVERTHELESS...THERE WILL BE TWO TO AS
MUCH AS FOUR INCHES OF SNOW OVER SOUTHERNMOST PORTIONS OF THE
FORECAST AREA. FURTHER TO THE NORTH...AS HAS BEEN THE CASE MUCH OF
THIS WINTER...LESS SNOW WILL FALL.

TEMPERATURES WILL BE MODERATING BUT STILL BELOW NORMAL FOR THIS
TIME OF THE YEAR.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
A SURFACE LOW EXITS RAPIDLY EAST INTO THE MARITIMES MONDAY WHILE
THE UPPER TROF MOVES THROUGH NORTHERN NEW ENGLAND. THE
PRECIPITATION WILL QUICKLY COME TO AN END EARLY MONDAY AS
DOWNSLOPING NORTHWEST WINDS KICK IN. HIGH PRESSURE BUILDS INTO THE
AREA MONDAY NIGHT AND TUESDAY. A FAST MOVING SHORT WAVE WITH
ASSOCIATED WARM AIR ADVECTION OVERRUNNING PRECIPITATION WILL MOVE
INTO THE AREA TUESDAY NIGHT IN THE FORM OF SNOW. SEVERAL INCHES OF
SNOW IS EXPECTED THROUGHOUT THE AREA. BY WEDNESDAY MORNING A BRIEF
CHANGEOVER TO A MIX OF RAIN OR SNOW SHOWERS OVER SOUTHERN AREAS IS
POSSIBLE BEFORE THE PRECIPITATION ENDS AS LOW AND MID LEVEL
TEMPERATURES MAY WARM ABOVE CRITICAL LEVELS. BY LATE WEDNESDAY
MORNING A COLD FRONT MOVES ACROSS THE AREA AND THEN OFFSHORE WITH
CLEARING BEHIND THE FRONT. HIGH PRESSURE BUILDS INTO THE REGION
FOR THURSDAY AND FRIDAY WITH FAIR CONDITIONS.

TEMPERATURES WILL GENERALLY REMAIN BELOW NORMAL FOR THE WEEK. USED
A BLEND OF THE MODELS FOR TEMPERATURES AND POPS.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
SHORT TERM...VFR CONDITIONS DETERIORATING TO MVFR AND IFR SUNDAY
NIGHT IN LIGHT SNOW.

LONG TERM...
MVFR TO IFR CONDITIONS EARLY MONDAY WILL IMPROVE TO VFR BY LATE
MORNING MONDAY AND CONTINUE THROUGH TUESDAY. TUESDAY NIGHT MVFR TO
IFR CONDITIONS WILL DEVELOP AND CONTINUE INTO WEDNESDAY MORNING.
CONDITIONS WILL RETURN TO VFR BY WEDNESDAY AFTERNOON AND CONTINUE
THROUGH FRIDAY.

&&

.MARINE...
SHORT TERM...NO FLAGS. WINDS BELOW SCA THRESHOLDS AS WELL AS SEAS
IN THE SHORT TERM PORTION OF THE FORECAST.

LONG TERM...EXPECT TO NEED A STRONG SCA MONDAY AFTERNOON INTO
MONDAY NIGHT IN AN INCREASING WEST FLOW...WINDS DIMINISH LATE
MONDAY NIGHT. SCA MAY BE NEEDED AGAIN IN A SOUTH TO SOUTHWEST
FLOW LATE TUESDAY NIGHT AND WEDNESDAY.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.

&&

$$

NEAR TERM UPDATE...KIMBLE
SHORT TERM...CANNON
LONG TERM...MARINE
AVIATION...CANNON/MARINE
MARINE...CANNON/MARINE




000
FXUS61 KBOX 010012
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
712 PM EST SAT FEB 28 2015

.SYNOPSIS...
A FAST MOVING LOW PRESSURE SYSTEM WILL BRING ACCUMULATING SNOW TO
THE REGION LATE SUNDAY INTO SUNDAY NIGHT...WITH THE HIGHEST AMOUNTS
EXPECTED SOUTH OF THE MASSACHUSETTS TURNPIKE AND AWAY FROM THE
IMMEDIATE SOUTH COAST. HIGH PRESSURE BRINGS DRY COLD AIR FOR THE
EARLY WEEK. LOW PRESSURE FROM NORTHERN CANADA AND ASSOCIATED LOW
FORMING OVER THE PLAINS MONDAY WILL MERGE...THEN PASS WEST AND
NORTH OF NEW ENGLAND. THIS WILL SWING A COLD FRONT ACROSS THE
REGION ON WEDNESDAY. DRY AND COLD WEATHER RETURNS FOR THE END OF
THE WEEK.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...

CLEAR SKIES AND LIGHT WIND WILL MEAN GOOD RADIATIONAL COOLING. MID
TO HIGH CLOUDS OVER OHIO EXTRAPOLATE TO WESTERN NEW ENGLAND AROUND
4 AM AND EASTERN SECTIONS AROUND 6 AM. DEW POINTS RANGE FROM
BELOW ZERO IN THE INTERIOR TO AROUND 10 ALONG THE SOUTH COAST.

LOOKING AT SUB- ZERO LOWS FOR LOW-LYING AREAS WHERE COLD-AIR
DRAINAGE EFFECTS OFF THE HIGH TERRAIN ARE MAXIMIZED. HIGH-TERRAIN
SHOULD REMAIN AT OR ABOVE ZERO.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
*/ SUNDAY MORNING INTO MIDDAY...

QUIET WEATHER. CLOUDS THICKENING AS WINDS INCREASE OUT OF THE S.
WILL SEE TEMPERATURES GRADUALLY MODERATE INTO THE MID- TO UPPER-20S.

*/ SUNDAY AFTERNOON INTO EARLY MONDAY MORNING...

1) HIGHLIGHTS...

 - SNOW SUNDAY AFTERNOON INTO MONDAY MORNING
 - GREATEST INTENSITY SUNDAY EVENING AND OVERNIGHT
 - 6+ INCH SNOWFALLS EXPECTED BUT EXACTLY WHERE REMAINS UNCERTAIN
 - ANNOYINGLY...FORECAST GUIDANCE CONTINUES TO WOBBLE

1) OVERVIEW...

BROAD ISENTROPIC OVER-RUNNING EVENT OF GULF MOISTURE ALONG THE 275-
295K SURFACES AMPLIFIED BY A N-STREAM IMPULSE DURING THE TIMEFRAME
POSSIBLY INVOKING AN AREA OF LOW PRESSURE THAT SKIRTS ALONG THE S-
COAST SUBSEQUENTLY ENHANCING LOW-LEVEL WIND PROFILE. LIGHT-MODERATE
SNOWFALL IS ANTICIPATED WITH LOCALLY HEAVIER AMOUNTS. THE INTENSE
PORTION OF SNOWFALL IS EXPECTED SUNDAY EVENING AND OVERNIGHT ENDING
EARLY MONDAY MORNING.

MODEL PREFERENCE GIVEN TO THE ECMWF/GFS/REGIONAL CANADIAN WHICH WILL
SERVE AS THE CONSENSUS OF GUIDANCE FOR THIS DISCUSSION. THE 28.12Z
NAM WAS CONSIDERED AN OUTLIER WITH ITS AGGRESSIVE-MODE AND SECONDARY
LOW DEVELOPMENT JUST OFFSHORE.

2) PRECIPITATION-TYPE...

EVALUATING THERMAL FIELDS...BLEND OF FORECAST CONSENSUS PUTS THE
-2C H925 ISOTHERM W-E ACROSS S-TIER OF CT/RI AND ACROSS SE MA WITH
THE 0C H85 ISOTHERM JUST S OF LONG-ISLAND AND NANTUCKET COASTLINES.
THE CONSENSUS OF 1000-850 MB CRITICAL THICKNESSES LAYS RIGHT ALONG
THE IMMEDIATE S-COAST OF LONG-ISLAND AND CAPE COD.

AN ALL SNOW-EVENT WHEN CONSIDERING DYNAMIC-COOLING/WETBULBING OF THE
LOW-LEVELS AHEAD OF THE EVENT. THERE IS PERHAPS A CHANCE OF A BRIEF
MIX-OVER TO RAIN/FREEZING RAIN ACROSS THE CAPE AND ISLANDS AS S-FLOW
AT THE SURFACE IS POSSIBLY ABLE TO NUDGE ABOVE-FREEZING TEMPERATURES
N. YET AS WE ARE IN A FROZEN TUNDRA...WITH ANY RAIN IT WOULD LIKELY
FREEZE ON SURFACES WHICH ARE QUITE COLD. THUS FREEZING RAIN PREVAILS
OVER RAIN IN THE FORECAST.

3) SNOWFALL...

FORECAST CONSENSUS OF A 0.3-0.6 N-S PRECIPITATION EVENT WITH A N-S
SNOW-TO-LIQUID RATIO GRADIENT RANGING FROM 15:1 TO 10:1 YIELDS HIGH-
END SNOW ADVISORY CRITERIA WITH SNOWFALL AMOUNTS RANGING ON AVERAGE
AROUND 3-6 INCHES. AREAS OF 6+ INCHES ARE EXPECTED...ESPECIALLY FROM
CENTRAL-CT E INTO SE-MA /INCLUDING THE UPPER-CAPE/. A CHALLENGE AND
A LOT OF UNCERTAINTY WITH RESPECT TO HEADLINES AND DECISION-MAKING.

EVALUATING LOW-LEVEL THERMAL PROFILES TOWARDS SNOW-TO-LIQUID RATIOS
DERIVED VIA A COBB-TECHNIQUE...WITH THE GREATEST LIFT OCCURRING
JUST BENEATH OR WITHIN THE DENDRITIC-GROWTH ZONE BASED ON A
CONSENSUS OF BUFKIT GFS PROFILES...ESPECIALLY IN HEAVIER- PRECIP
AREAS...BELIEVE THE SNOW WILL RANGE SOMEWHERE BETWEEN A WET AND
FLUFFY SNOW. SNOW PROPERTIES FROM FLUFFY TO WET LIKELY SIMILAR TO
THE N-S GRADIENT AS OUTLINED ABOVE.

4) HEADLINES...

HATE A WOBBLING FORECAST WHICH IS TYPICAL WITH SUCH SMALL EVENTS.
UNCERTAINTY DERIVES FROM LOW-LEVEL THERMAL PROFILES AND PRECIP
AMOUNTS. SURELY EXPECTING SNOW...BUT WITH ANY SHIFT N-S OF COLDER
AIR AND/OR PRECIPITATION AMOUNTS RESULTS IN AREAS SHIFTING FROM
ADVISORY TO WARNING...OR VICE VERSA. ENOUGH TO JUST PULL YOUR HAIR
OUT. THEN THERE IS THE TIMING OF THE SYSTEM THAT HAS SPED UP
SLIGHTLY. A SHORTER RESIDENCE TIME OF COURSE WOULD YIELD LESSER
SNOWFALL AMOUNTS. QUITE A CHALLENGING FORECAST RIGHT ON THE CUSP
OF HEADLINE THRESHOLDS.

THE EVENT DOES TAKE PLACE MAINLY FROM SUNDAY EVENING INTO THE EARLY
MORNING HOURS ON MONDAY DURING WHICH TIME THERE IS NOT MUCH TRAFFIC
ON THE ROAD. IS THIS A HIGH IMPACT EVENT THAT WARRANTS WARNINGS? A
QUESTION TO STRUGGLE WITH AS WARNINGS ARE NECESSARY WHEN WE ARE
CONFIDENT IN MEETING OR EXCEEDING 6+ INCH CRITERIA. YET THE QUESTION
IN FRONT OF US IS WHERE WILL THE HIGHER AMOUNTS OF SNOW FOCUS? HAVE
TO MAKE SOME SORT OF CALL...THE NEEDS OF THE MANY OUTWEIGH THE NEEDS
OF THE FEW.

ADVISORIES POSTED WHERE THERE IS HIGH CONFIDENCE OF SNOW BUT LIKELY
TO REMAIN BELOW THE 6-INCH THRESHOLD FOR WARNING. WATCHES CONTINUE
AND HAVE BEEN EXTENDED TO THE S-COAST TO COVER FOR THE UNCERTAINTY
OF THE AREA EITHER FALLING WITHIN OR IN EXCESS OF ADVISORY-LEVEL
SNOWS. AGAIN...6+ INCH AMOUNTS ARE ANTICIPATED BUT EXACTLY WHERE IS
UNCERTAIN.

5) CLOSING NOTES...

SOME CONCERN FOR THE EARLY MONDAY MORNING COMMUTE FOR E/SE MA AND
RI. WHILE MOST OF THE SNOW IS EXPECTED TO BE IMMEDIATELY OFFSHORE
WITH SUNRISE MONDAY...COMMUTERS COULD ENCOUNTER SLICK AND SLIPPERY
ROAD CONDITIONS. SNOW COULD POSSIBLY LINGER OVER SE MA SO THERE IS
THE POTENTIAL FOR REDUCED VISIBILITIES.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
BIG PICTURE... THE BROAD UPPER FLOW SHOWS A RIDGE IN THE EAST AND
TROUGH IN THE WEST WITH A WEST SOUTHWEST FLOW FROM THE PLAINS TO THE
EASTERN USA COAST. WITHIN THIS FLOW ARE BOTH NORTHERN AND SOUTHERN
STREAMS AT THE START OF THE WEEK. THE WESTERN TROUGH MIGRATES EAST
DURING THE MIDWEEK AT WHICH TIME THE TWO STREAMS MERGE TO FORM A 140-
160 KT UPPER JET FEEDING NORTHEAST INTO THE GREAT LAKES AND ST
LAWRENCE VALLEY. THIS JET LINGERS OVER OR NEAR NEW ENGLAND THURSDAY-
FRIDAY BEFORE MOVING OFF. THE WESTERN TROUGH MOVES ACROSS NEW
ENGLAND BY THE END OF THE WEEK.

DAILIES...

MONDAY... SUNDAY STORM MOVES OFF PAST NOVA SCOTIA WHILE THE
SUPPORTING UPPER SHORTWAVE AND COLD POOL SWING ACROSS NEW ENGLAND.
THE COOLEST AIR ALOFT IS IN NORTHERN NEW ENGLAND WHILE LEFTOVER
MOISTURE LINGERS BELOW 800 MB THROUGH THE DAY. THE GFS IS FASTER
THAN THE ECMWF IN BRINGING RISING PRESSURE TO THE REGION BUT HAVE 1
MB/HOUR RISES HERE BY EVENING. PUT TOGETHER...EXPECT A CLEARING
TREND BUT WITH LEFTOVER CLOUDS ESPECIALLY NORTH OF THE MASS PIKE.
SUSTAINED NORTHWEST WINDS SHOULD RISE TO 15-20 KTS. MIXING REACHES
TO AT LEAST 850 MB AND POSSIBLY A LITTLE HIGHER...WHICH SUPPORTS
GUSTS TO AT LEAST 30 KNOTS AND POSSIBLY 35 KNOTS. TEMPS AT 850 MB
WILL BE -11C TO -14C...MIXING THIS TO THE SURFACE WOULD SUPPORT MAX
SFC TEMPS IN THE 30S. MIN TEMPERATURES UPSTREAM THIS MORNING WERE IN
THE SINGLE NUMBERS WITH A FEW SPOTS BELOW ZERO. WITH LIGHT PRESSURE
GRADIENT ESP IN THE WEST...WE TENDED A FEW DEGREES COOLER THAN
CONSENSUS.

TUESDAY-WEDNESDAY... HIGH PRESSURE IN CONTROL MUCH OF TUESDAY BUT
MOVING OFFSHORE DURING THE AFTERNOON. CROSS SECTIONS SHOW INCREASING
MOISTURE AT MID AND HIGH CLOUD LEVEL...SO INCREASING HIGH CLOUDS.
SYSTEM MOVING INTO THE GREAT LAKES SPREADS PCPN INTO NEW YORK...BUT
WARM ADVECTION LIFT REMAINS MOSTLY TO OUR WEST THROUGH THE
AFTERNOON. SOME LIFT FORECAST AT 290K /ABOUT 730 MB AT THE TIME/ BUT
NONE BELOW THAT. MEANWHILE DEWPOINTS IN THE SINGLE NUMBERS PROGRESS
INTO THE TEENS DURING THE DAY...BUT ENOUGH OF A TEMP/DEWPOINT SPREAD
TO SLOW THE ADVANCE OF ANY PCPN FROM THE CLOUDS BY A FEW HOURS.

WARM ADVECTION LIFT MUCH OF THE NIGHT SUPPORTS THE IDEA OF PCPN.
TEMPERATURES START COLD DURING THE EVENING BUT SHOULD RISE
OVERNIGHT. THE QUESTION REMAINS AS TO HOW HIGH THEY WILL CLIMB. EVEN
WITH THE SURFACE SYSTEM TRACKING UP THE ST LAWRENCE VALLEY THERE IS
COLD GROUND AND A COLD SNOWPACK. THIS WOULD ALLOW THE WARMER TEMPS
TO SCREAM OVERHEAD WHILE THE IMMEDIATE SURFACE REMAINS SEVERAL
DEGREES COLDER. WE TRIMMED TEMPS BACK A LITTLE FROM MODEL
VALUES...BUT LOW CONFIDENCE AT THIS TIME DUE TO THE POTENTIAL THAT
SURFACE TEMPS COULD REMAIN IN THE 30S.

QPF FORECASTS RANGE FROM 0.50 TO 1.00 INCHES WITH THE HIGHER AMOUNTS
TENDING TOWARD THE SOUTH COAST. THIS POINTS TO A MESSY STORM WITH
INITIAL SNOW ACCUMS OF SEVERAL INCHES FOLLOWED BY A CHANGE TO
MEASUREABLE ICE ACCUMULATION AND THEN A CHANGE TO RAIN WITH
POTENTIAL FOR POOR DRAINAGE FLOODING IN BETWEEN THE SNOW BANKS.

THE COLD FRONT SHOULD MOVE THROUGH DURING THE AFTERNOON/EVENING WITH
A SHIFT TO NORTHWEST WINDS. THIS WILL CHANGE THE PCPN BACK TO SNOW
BEFORE TAPERING OFF.

THURSDAY...DIFERENCES IN THE GFS AND ECMWF IN HANDING THE UPPER JET.
THE ECMWF MOVES THE JET OFFSHORE AND PUTS SOUTHERN NEW ENGLAND
INTO SUBSIDENCE. THE GFS MAINTAINS THE JET OVERHEAD WITH OUR AREA
IN THE RIGHT ENTRANCE REGION. THE FIRST SCENARIO ENDS THE PCPN AND
COOLS THE AIR. THE SECOND SCENARIO WOULD SUPPORT LIFT AND GENERATE
WAVES ALONG THE DEPARTING COLD FRONT...MAINTAINING A CHANCE OF
SNOW OVER AT LEAST SOUTHERN PARTS OF OUR AREA. OUR THURSDAY
FORECAST TENDS TOWARD THE LATTER FOR NOW.

FRIDAY-SATURDAY... HIGH PRESSURE BUILDS OVER THE REGION THURSDAY
NIGHT AND FRIDAY WITH CLEARING SKIES AND A BRIEF PERIOD OF COLD AIR.
TEMPS ALOFT TREND UP ABOUT 10C ON SATURDAY SUGGESTING LESS CHILL AT
THE SURFACE. ANOTHER COLD FRONT APPROACHES THE ST LAWRENCE VALLEY
AND COULD SPREAD SOME CLOUDS INTO OUR AREA SATURDAY
AFTERNOON/EVENING. BUT PCPN CHANCES LOOK SMALL.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /THROUGH MONDAY MORNING/...

TONIGHT THROUGH SUNDAY MIDDAY...HIGH CONFIDENCE.

VFR. LOWERING AND THICKENING CLOUDS SUNDAY MORNING INTO MIDDAY.

SUNDAY AFTERNOON INTO MONDAY MORNING...MODERATE CONFIDENCE.

SNOW OVERSPREADS THE REGION W-E. CIGS/VSBYS DETERIORATE TO MVFR-
IFR BY EARLY EVENING...WIDESPREAD IFR-LIFR SUNDAY NIGHT. SN TO MIX
WITH OR CHANGE TO FZRA ACROSS OFFSHORE ISLAND TERMINALS OVERNIGHT.
PRECIP ENDS W-E TOWARD DAYBREAK MONDAY....CONDITIONS IMPROVE.

KBOS TAF...MODERATE CONFIDENCE. TRENDS CERTAIN BUT NOT SO MUCH THE
ACTUAL TIMING OF IMPACTS.

KBDL TAF...MODERATE CONFIDENCE. TRENDS CERTAIN BUT NOT SO MUCH
THE ACTUAL TIMING OF IMPACTS.

OUTLOOK...MONDAY THROUGH THURSDAY...

MONDAY... HIGH CONFIDENCE. SOME IFR/MVFR IN SNOW EARLY MORNING BUT
OTHERWISE CONDITIONS WILL IMPROVE TO VFR DURING THE MORNING.
NORTHWEST WINDS WILL INCREASE WITH GUSTS AROUND 30 KNOTS BY MIDDAY.
VFR AND DIMINISHING WIND MONDAY NIGHT.

TUESDAY...MODERATE CONFIDENCE. VFR DURING THE DAY WITH INCREASING
SKY COVER. MVFR TUESDAY EVENING BECOMING IFR/LIFR OVERNIGHT IN
DEVELOPING SNOW AND FREEZING RAIN.

WEDNESDAY...MODERATE CONFIDENCE. IFR/LIFR IN RAIN AND FREEZING RAIN.

THURSDAY...LOW CONFIDENCE. VFR NORTH OF A HFD-BOS LINE. MVFR CIGS
AND AREAS OF MVFR/IFR VSBYS IN SNOW.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /THROUGH MONDAY MORNING/...HIGH CONFIDENCE.

HIGH PRESSURE NEARBY WILL KEEP WINDS/SEAS WELL BELOW SMALL CRAFT
ADVISORY THRESHOLDS INTO SUNDAY MORNING. A WEAK WAVE OF LOW
PRESSURE MOVES ACROSS THE WATERS LATE SUNDAY INTO SUNDAY NIGHT...
BUT WEAK PRESSURE GRADIENT SHOULD KEEP WINDS/SEAS BELOW SMALL
CRAFT THRESHOLDS.

OUTLOOK...MONDAY THROUGH THURSDAY..MODERATE CONFIDENCE.

MONDAY...WEST TO NORTHWEST WINDS INCREASE WITH FREQUENT GUSTS TO
GALE FORCE ESPECIALLY AWAY FROM THE NEARSHORE. THIS COULD GENERATE
SOME LIGHT FREEZING SPRAY ESPECIALLY EARLY MONDAY NIGHT. SEAS 5
TO 10 FEET. WINDS AND SEAS DIMINISH MONDAY NIGHT. A GALE WARNING
MAY BE NEEDED.

TUESDAY... LINGERING 5 FOOT SEAS ON THE OUTER WATERS BUT DIMINISHING
DURING THE MORNING.  WINDS AND SEAS INCREASE AGAIN TUESDAY NIGHT
AFTER MIDNIGHT AHEAD OF A GREAT LAKES COLD FRONT. SOUTH WINDS WILL
APPROACH 25 KNOTS WITH SEAS BUILDING TO 5 TO 8 FEET. VSBYS WILL
BE REDUCED IN SNOW CHANGING TO RAIN.

WEDNESDAY...SOUTHWEST WINDS WITH GUSTS 25-30 KNOTS.  SEAS BUILDING
TO 6 TO 12 FEET. REDUCED VSBYS IN RAIN. A SMALL CRAFT ADVISORY MAY
BE NEEDED.

THURSDAY...NORTHWEST WINDS WILL GUST TO 25 KNOTS...AND SEAS 5 TO 8
FEET. BOTH SHOULD DIMINISH TOWARD EVENING.  A SMALL CRAFT ADVISORY
MAY BE NEEDED.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY
     MORNING FOR CTZ002>004.
MA...WINTER WEATHER ADVISORY FROM NOON SUNDAY TO 7 AM EST MONDAY
     FOR MAZ002>008-010-014-023-024-026.
     WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY
     MORNING FOR MAZ009-011>013-015>022.
RI...WINTER WEATHER ADVISORY FROM NOON SUNDAY TO 7 AM EST MONDAY
     FOR RIZ008.
     WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY
     MORNING FOR RIZ001>007.
MARINE...NONE.

&&

$$
SYNOPSIS...WTB/SIPPRELL
NEAR TERM...WTB/SIPPRELL
SHORT TERM...SIPPRELL
LONG TERM...WTB
AVIATION...WTB/SIPPRELL
MARINE...WTB/SIPPRELL



000
FXUS61 KBOX 010012
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
712 PM EST SAT FEB 28 2015

.SYNOPSIS...
A FAST MOVING LOW PRESSURE SYSTEM WILL BRING ACCUMULATING SNOW TO
THE REGION LATE SUNDAY INTO SUNDAY NIGHT...WITH THE HIGHEST AMOUNTS
EXPECTED SOUTH OF THE MASSACHUSETTS TURNPIKE AND AWAY FROM THE
IMMEDIATE SOUTH COAST. HIGH PRESSURE BRINGS DRY COLD AIR FOR THE
EARLY WEEK. LOW PRESSURE FROM NORTHERN CANADA AND ASSOCIATED LOW
FORMING OVER THE PLAINS MONDAY WILL MERGE...THEN PASS WEST AND
NORTH OF NEW ENGLAND. THIS WILL SWING A COLD FRONT ACROSS THE
REGION ON WEDNESDAY. DRY AND COLD WEATHER RETURNS FOR THE END OF
THE WEEK.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...

CLEAR SKIES AND LIGHT WIND WILL MEAN GOOD RADIATIONAL COOLING. MID
TO HIGH CLOUDS OVER OHIO EXTRAPOLATE TO WESTERN NEW ENGLAND AROUND
4 AM AND EASTERN SECTIONS AROUND 6 AM. DEW POINTS RANGE FROM
BELOW ZERO IN THE INTERIOR TO AROUND 10 ALONG THE SOUTH COAST.

LOOKING AT SUB- ZERO LOWS FOR LOW-LYING AREAS WHERE COLD-AIR
DRAINAGE EFFECTS OFF THE HIGH TERRAIN ARE MAXIMIZED. HIGH-TERRAIN
SHOULD REMAIN AT OR ABOVE ZERO.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
*/ SUNDAY MORNING INTO MIDDAY...

QUIET WEATHER. CLOUDS THICKENING AS WINDS INCREASE OUT OF THE S.
WILL SEE TEMPERATURES GRADUALLY MODERATE INTO THE MID- TO UPPER-20S.

*/ SUNDAY AFTERNOON INTO EARLY MONDAY MORNING...

1) HIGHLIGHTS...

 - SNOW SUNDAY AFTERNOON INTO MONDAY MORNING
 - GREATEST INTENSITY SUNDAY EVENING AND OVERNIGHT
 - 6+ INCH SNOWFALLS EXPECTED BUT EXACTLY WHERE REMAINS UNCERTAIN
 - ANNOYINGLY...FORECAST GUIDANCE CONTINUES TO WOBBLE

1) OVERVIEW...

BROAD ISENTROPIC OVER-RUNNING EVENT OF GULF MOISTURE ALONG THE 275-
295K SURFACES AMPLIFIED BY A N-STREAM IMPULSE DURING THE TIMEFRAME
POSSIBLY INVOKING AN AREA OF LOW PRESSURE THAT SKIRTS ALONG THE S-
COAST SUBSEQUENTLY ENHANCING LOW-LEVEL WIND PROFILE. LIGHT-MODERATE
SNOWFALL IS ANTICIPATED WITH LOCALLY HEAVIER AMOUNTS. THE INTENSE
PORTION OF SNOWFALL IS EXPECTED SUNDAY EVENING AND OVERNIGHT ENDING
EARLY MONDAY MORNING.

MODEL PREFERENCE GIVEN TO THE ECMWF/GFS/REGIONAL CANADIAN WHICH WILL
SERVE AS THE CONSENSUS OF GUIDANCE FOR THIS DISCUSSION. THE 28.12Z
NAM WAS CONSIDERED AN OUTLIER WITH ITS AGGRESSIVE-MODE AND SECONDARY
LOW DEVELOPMENT JUST OFFSHORE.

2) PRECIPITATION-TYPE...

EVALUATING THERMAL FIELDS...BLEND OF FORECAST CONSENSUS PUTS THE
-2C H925 ISOTHERM W-E ACROSS S-TIER OF CT/RI AND ACROSS SE MA WITH
THE 0C H85 ISOTHERM JUST S OF LONG-ISLAND AND NANTUCKET COASTLINES.
THE CONSENSUS OF 1000-850 MB CRITICAL THICKNESSES LAYS RIGHT ALONG
THE IMMEDIATE S-COAST OF LONG-ISLAND AND CAPE COD.

AN ALL SNOW-EVENT WHEN CONSIDERING DYNAMIC-COOLING/WETBULBING OF THE
LOW-LEVELS AHEAD OF THE EVENT. THERE IS PERHAPS A CHANCE OF A BRIEF
MIX-OVER TO RAIN/FREEZING RAIN ACROSS THE CAPE AND ISLANDS AS S-FLOW
AT THE SURFACE IS POSSIBLY ABLE TO NUDGE ABOVE-FREEZING TEMPERATURES
N. YET AS WE ARE IN A FROZEN TUNDRA...WITH ANY RAIN IT WOULD LIKELY
FREEZE ON SURFACES WHICH ARE QUITE COLD. THUS FREEZING RAIN PREVAILS
OVER RAIN IN THE FORECAST.

3) SNOWFALL...

FORECAST CONSENSUS OF A 0.3-0.6 N-S PRECIPITATION EVENT WITH A N-S
SNOW-TO-LIQUID RATIO GRADIENT RANGING FROM 15:1 TO 10:1 YIELDS HIGH-
END SNOW ADVISORY CRITERIA WITH SNOWFALL AMOUNTS RANGING ON AVERAGE
AROUND 3-6 INCHES. AREAS OF 6+ INCHES ARE EXPECTED...ESPECIALLY FROM
CENTRAL-CT E INTO SE-MA /INCLUDING THE UPPER-CAPE/. A CHALLENGE AND
A LOT OF UNCERTAINTY WITH RESPECT TO HEADLINES AND DECISION-MAKING.

EVALUATING LOW-LEVEL THERMAL PROFILES TOWARDS SNOW-TO-LIQUID RATIOS
DERIVED VIA A COBB-TECHNIQUE...WITH THE GREATEST LIFT OCCURRING
JUST BENEATH OR WITHIN THE DENDRITIC-GROWTH ZONE BASED ON A
CONSENSUS OF BUFKIT GFS PROFILES...ESPECIALLY IN HEAVIER- PRECIP
AREAS...BELIEVE THE SNOW WILL RANGE SOMEWHERE BETWEEN A WET AND
FLUFFY SNOW. SNOW PROPERTIES FROM FLUFFY TO WET LIKELY SIMILAR TO
THE N-S GRADIENT AS OUTLINED ABOVE.

4) HEADLINES...

HATE A WOBBLING FORECAST WHICH IS TYPICAL WITH SUCH SMALL EVENTS.
UNCERTAINTY DERIVES FROM LOW-LEVEL THERMAL PROFILES AND PRECIP
AMOUNTS. SURELY EXPECTING SNOW...BUT WITH ANY SHIFT N-S OF COLDER
AIR AND/OR PRECIPITATION AMOUNTS RESULTS IN AREAS SHIFTING FROM
ADVISORY TO WARNING...OR VICE VERSA. ENOUGH TO JUST PULL YOUR HAIR
OUT. THEN THERE IS THE TIMING OF THE SYSTEM THAT HAS SPED UP
SLIGHTLY. A SHORTER RESIDENCE TIME OF COURSE WOULD YIELD LESSER
SNOWFALL AMOUNTS. QUITE A CHALLENGING FORECAST RIGHT ON THE CUSP
OF HEADLINE THRESHOLDS.

THE EVENT DOES TAKE PLACE MAINLY FROM SUNDAY EVENING INTO THE EARLY
MORNING HOURS ON MONDAY DURING WHICH TIME THERE IS NOT MUCH TRAFFIC
ON THE ROAD. IS THIS A HIGH IMPACT EVENT THAT WARRANTS WARNINGS? A
QUESTION TO STRUGGLE WITH AS WARNINGS ARE NECESSARY WHEN WE ARE
CONFIDENT IN MEETING OR EXCEEDING 6+ INCH CRITERIA. YET THE QUESTION
IN FRONT OF US IS WHERE WILL THE HIGHER AMOUNTS OF SNOW FOCUS? HAVE
TO MAKE SOME SORT OF CALL...THE NEEDS OF THE MANY OUTWEIGH THE NEEDS
OF THE FEW.

ADVISORIES POSTED WHERE THERE IS HIGH CONFIDENCE OF SNOW BUT LIKELY
TO REMAIN BELOW THE 6-INCH THRESHOLD FOR WARNING. WATCHES CONTINUE
AND HAVE BEEN EXTENDED TO THE S-COAST TO COVER FOR THE UNCERTAINTY
OF THE AREA EITHER FALLING WITHIN OR IN EXCESS OF ADVISORY-LEVEL
SNOWS. AGAIN...6+ INCH AMOUNTS ARE ANTICIPATED BUT EXACTLY WHERE IS
UNCERTAIN.

5) CLOSING NOTES...

SOME CONCERN FOR THE EARLY MONDAY MORNING COMMUTE FOR E/SE MA AND
RI. WHILE MOST OF THE SNOW IS EXPECTED TO BE IMMEDIATELY OFFSHORE
WITH SUNRISE MONDAY...COMMUTERS COULD ENCOUNTER SLICK AND SLIPPERY
ROAD CONDITIONS. SNOW COULD POSSIBLY LINGER OVER SE MA SO THERE IS
THE POTENTIAL FOR REDUCED VISIBILITIES.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
BIG PICTURE... THE BROAD UPPER FLOW SHOWS A RIDGE IN THE EAST AND
TROUGH IN THE WEST WITH A WEST SOUTHWEST FLOW FROM THE PLAINS TO THE
EASTERN USA COAST. WITHIN THIS FLOW ARE BOTH NORTHERN AND SOUTHERN
STREAMS AT THE START OF THE WEEK. THE WESTERN TROUGH MIGRATES EAST
DURING THE MIDWEEK AT WHICH TIME THE TWO STREAMS MERGE TO FORM A 140-
160 KT UPPER JET FEEDING NORTHEAST INTO THE GREAT LAKES AND ST
LAWRENCE VALLEY. THIS JET LINGERS OVER OR NEAR NEW ENGLAND THURSDAY-
FRIDAY BEFORE MOVING OFF. THE WESTERN TROUGH MOVES ACROSS NEW
ENGLAND BY THE END OF THE WEEK.

DAILIES...

MONDAY... SUNDAY STORM MOVES OFF PAST NOVA SCOTIA WHILE THE
SUPPORTING UPPER SHORTWAVE AND COLD POOL SWING ACROSS NEW ENGLAND.
THE COOLEST AIR ALOFT IS IN NORTHERN NEW ENGLAND WHILE LEFTOVER
MOISTURE LINGERS BELOW 800 MB THROUGH THE DAY. THE GFS IS FASTER
THAN THE ECMWF IN BRINGING RISING PRESSURE TO THE REGION BUT HAVE 1
MB/HOUR RISES HERE BY EVENING. PUT TOGETHER...EXPECT A CLEARING
TREND BUT WITH LEFTOVER CLOUDS ESPECIALLY NORTH OF THE MASS PIKE.
SUSTAINED NORTHWEST WINDS SHOULD RISE TO 15-20 KTS. MIXING REACHES
TO AT LEAST 850 MB AND POSSIBLY A LITTLE HIGHER...WHICH SUPPORTS
GUSTS TO AT LEAST 30 KNOTS AND POSSIBLY 35 KNOTS. TEMPS AT 850 MB
WILL BE -11C TO -14C...MIXING THIS TO THE SURFACE WOULD SUPPORT MAX
SFC TEMPS IN THE 30S. MIN TEMPERATURES UPSTREAM THIS MORNING WERE IN
THE SINGLE NUMBERS WITH A FEW SPOTS BELOW ZERO. WITH LIGHT PRESSURE
GRADIENT ESP IN THE WEST...WE TENDED A FEW DEGREES COOLER THAN
CONSENSUS.

TUESDAY-WEDNESDAY... HIGH PRESSURE IN CONTROL MUCH OF TUESDAY BUT
MOVING OFFSHORE DURING THE AFTERNOON. CROSS SECTIONS SHOW INCREASING
MOISTURE AT MID AND HIGH CLOUD LEVEL...SO INCREASING HIGH CLOUDS.
SYSTEM MOVING INTO THE GREAT LAKES SPREADS PCPN INTO NEW YORK...BUT
WARM ADVECTION LIFT REMAINS MOSTLY TO OUR WEST THROUGH THE
AFTERNOON. SOME LIFT FORECAST AT 290K /ABOUT 730 MB AT THE TIME/ BUT
NONE BELOW THAT. MEANWHILE DEWPOINTS IN THE SINGLE NUMBERS PROGRESS
INTO THE TEENS DURING THE DAY...BUT ENOUGH OF A TEMP/DEWPOINT SPREAD
TO SLOW THE ADVANCE OF ANY PCPN FROM THE CLOUDS BY A FEW HOURS.

WARM ADVECTION LIFT MUCH OF THE NIGHT SUPPORTS THE IDEA OF PCPN.
TEMPERATURES START COLD DURING THE EVENING BUT SHOULD RISE
OVERNIGHT. THE QUESTION REMAINS AS TO HOW HIGH THEY WILL CLIMB. EVEN
WITH THE SURFACE SYSTEM TRACKING UP THE ST LAWRENCE VALLEY THERE IS
COLD GROUND AND A COLD SNOWPACK. THIS WOULD ALLOW THE WARMER TEMPS
TO SCREAM OVERHEAD WHILE THE IMMEDIATE SURFACE REMAINS SEVERAL
DEGREES COLDER. WE TRIMMED TEMPS BACK A LITTLE FROM MODEL
VALUES...BUT LOW CONFIDENCE AT THIS TIME DUE TO THE POTENTIAL THAT
SURFACE TEMPS COULD REMAIN IN THE 30S.

QPF FORECASTS RANGE FROM 0.50 TO 1.00 INCHES WITH THE HIGHER AMOUNTS
TENDING TOWARD THE SOUTH COAST. THIS POINTS TO A MESSY STORM WITH
INITIAL SNOW ACCUMS OF SEVERAL INCHES FOLLOWED BY A CHANGE TO
MEASUREABLE ICE ACCUMULATION AND THEN A CHANGE TO RAIN WITH
POTENTIAL FOR POOR DRAINAGE FLOODING IN BETWEEN THE SNOW BANKS.

THE COLD FRONT SHOULD MOVE THROUGH DURING THE AFTERNOON/EVENING WITH
A SHIFT TO NORTHWEST WINDS. THIS WILL CHANGE THE PCPN BACK TO SNOW
BEFORE TAPERING OFF.

THURSDAY...DIFERENCES IN THE GFS AND ECMWF IN HANDING THE UPPER JET.
THE ECMWF MOVES THE JET OFFSHORE AND PUTS SOUTHERN NEW ENGLAND
INTO SUBSIDENCE. THE GFS MAINTAINS THE JET OVERHEAD WITH OUR AREA
IN THE RIGHT ENTRANCE REGION. THE FIRST SCENARIO ENDS THE PCPN AND
COOLS THE AIR. THE SECOND SCENARIO WOULD SUPPORT LIFT AND GENERATE
WAVES ALONG THE DEPARTING COLD FRONT...MAINTAINING A CHANCE OF
SNOW OVER AT LEAST SOUTHERN PARTS OF OUR AREA. OUR THURSDAY
FORECAST TENDS TOWARD THE LATTER FOR NOW.

FRIDAY-SATURDAY... HIGH PRESSURE BUILDS OVER THE REGION THURSDAY
NIGHT AND FRIDAY WITH CLEARING SKIES AND A BRIEF PERIOD OF COLD AIR.
TEMPS ALOFT TREND UP ABOUT 10C ON SATURDAY SUGGESTING LESS CHILL AT
THE SURFACE. ANOTHER COLD FRONT APPROACHES THE ST LAWRENCE VALLEY
AND COULD SPREAD SOME CLOUDS INTO OUR AREA SATURDAY
AFTERNOON/EVENING. BUT PCPN CHANCES LOOK SMALL.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /THROUGH MONDAY MORNING/...

TONIGHT THROUGH SUNDAY MIDDAY...HIGH CONFIDENCE.

VFR. LOWERING AND THICKENING CLOUDS SUNDAY MORNING INTO MIDDAY.

SUNDAY AFTERNOON INTO MONDAY MORNING...MODERATE CONFIDENCE.

SNOW OVERSPREADS THE REGION W-E. CIGS/VSBYS DETERIORATE TO MVFR-
IFR BY EARLY EVENING...WIDESPREAD IFR-LIFR SUNDAY NIGHT. SN TO MIX
WITH OR CHANGE TO FZRA ACROSS OFFSHORE ISLAND TERMINALS OVERNIGHT.
PRECIP ENDS W-E TOWARD DAYBREAK MONDAY....CONDITIONS IMPROVE.

KBOS TAF...MODERATE CONFIDENCE. TRENDS CERTAIN BUT NOT SO MUCH THE
ACTUAL TIMING OF IMPACTS.

KBDL TAF...MODERATE CONFIDENCE. TRENDS CERTAIN BUT NOT SO MUCH
THE ACTUAL TIMING OF IMPACTS.

OUTLOOK...MONDAY THROUGH THURSDAY...

MONDAY... HIGH CONFIDENCE. SOME IFR/MVFR IN SNOW EARLY MORNING BUT
OTHERWISE CONDITIONS WILL IMPROVE TO VFR DURING THE MORNING.
NORTHWEST WINDS WILL INCREASE WITH GUSTS AROUND 30 KNOTS BY MIDDAY.
VFR AND DIMINISHING WIND MONDAY NIGHT.

TUESDAY...MODERATE CONFIDENCE. VFR DURING THE DAY WITH INCREASING
SKY COVER. MVFR TUESDAY EVENING BECOMING IFR/LIFR OVERNIGHT IN
DEVELOPING SNOW AND FREEZING RAIN.

WEDNESDAY...MODERATE CONFIDENCE. IFR/LIFR IN RAIN AND FREEZING RAIN.

THURSDAY...LOW CONFIDENCE. VFR NORTH OF A HFD-BOS LINE. MVFR CIGS
AND AREAS OF MVFR/IFR VSBYS IN SNOW.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /THROUGH MONDAY MORNING/...HIGH CONFIDENCE.

HIGH PRESSURE NEARBY WILL KEEP WINDS/SEAS WELL BELOW SMALL CRAFT
ADVISORY THRESHOLDS INTO SUNDAY MORNING. A WEAK WAVE OF LOW
PRESSURE MOVES ACROSS THE WATERS LATE SUNDAY INTO SUNDAY NIGHT...
BUT WEAK PRESSURE GRADIENT SHOULD KEEP WINDS/SEAS BELOW SMALL
CRAFT THRESHOLDS.

OUTLOOK...MONDAY THROUGH THURSDAY..MODERATE CONFIDENCE.

MONDAY...WEST TO NORTHWEST WINDS INCREASE WITH FREQUENT GUSTS TO
GALE FORCE ESPECIALLY AWAY FROM THE NEARSHORE. THIS COULD GENERATE
SOME LIGHT FREEZING SPRAY ESPECIALLY EARLY MONDAY NIGHT. SEAS 5
TO 10 FEET. WINDS AND SEAS DIMINISH MONDAY NIGHT. A GALE WARNING
MAY BE NEEDED.

TUESDAY... LINGERING 5 FOOT SEAS ON THE OUTER WATERS BUT DIMINISHING
DURING THE MORNING.  WINDS AND SEAS INCREASE AGAIN TUESDAY NIGHT
AFTER MIDNIGHT AHEAD OF A GREAT LAKES COLD FRONT. SOUTH WINDS WILL
APPROACH 25 KNOTS WITH SEAS BUILDING TO 5 TO 8 FEET. VSBYS WILL
BE REDUCED IN SNOW CHANGING TO RAIN.

WEDNESDAY...SOUTHWEST WINDS WITH GUSTS 25-30 KNOTS.  SEAS BUILDING
TO 6 TO 12 FEET. REDUCED VSBYS IN RAIN. A SMALL CRAFT ADVISORY MAY
BE NEEDED.

THURSDAY...NORTHWEST WINDS WILL GUST TO 25 KNOTS...AND SEAS 5 TO 8
FEET. BOTH SHOULD DIMINISH TOWARD EVENING.  A SMALL CRAFT ADVISORY
MAY BE NEEDED.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY
     MORNING FOR CTZ002>004.
MA...WINTER WEATHER ADVISORY FROM NOON SUNDAY TO 7 AM EST MONDAY
     FOR MAZ002>008-010-014-023-024-026.
     WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY
     MORNING FOR MAZ009-011>013-015>022.
RI...WINTER WEATHER ADVISORY FROM NOON SUNDAY TO 7 AM EST MONDAY
     FOR RIZ008.
     WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY
     MORNING FOR RIZ001>007.
MARINE...NONE.

&&

$$
SYNOPSIS...WTB/SIPPRELL
NEAR TERM...WTB/SIPPRELL
SHORT TERM...SIPPRELL
LONG TERM...WTB
AVIATION...WTB/SIPPRELL
MARINE...WTB/SIPPRELL




000
FXUS61 KBOX 010012
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
712 PM EST SAT FEB 28 2015

.SYNOPSIS...
A FAST MOVING LOW PRESSURE SYSTEM WILL BRING ACCUMULATING SNOW TO
THE REGION LATE SUNDAY INTO SUNDAY NIGHT...WITH THE HIGHEST AMOUNTS
EXPECTED SOUTH OF THE MASSACHUSETTS TURNPIKE AND AWAY FROM THE
IMMEDIATE SOUTH COAST. HIGH PRESSURE BRINGS DRY COLD AIR FOR THE
EARLY WEEK. LOW PRESSURE FROM NORTHERN CANADA AND ASSOCIATED LOW
FORMING OVER THE PLAINS MONDAY WILL MERGE...THEN PASS WEST AND
NORTH OF NEW ENGLAND. THIS WILL SWING A COLD FRONT ACROSS THE
REGION ON WEDNESDAY. DRY AND COLD WEATHER RETURNS FOR THE END OF
THE WEEK.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...

CLEAR SKIES AND LIGHT WIND WILL MEAN GOOD RADIATIONAL COOLING. MID
TO HIGH CLOUDS OVER OHIO EXTRAPOLATE TO WESTERN NEW ENGLAND AROUND
4 AM AND EASTERN SECTIONS AROUND 6 AM. DEW POINTS RANGE FROM
BELOW ZERO IN THE INTERIOR TO AROUND 10 ALONG THE SOUTH COAST.

LOOKING AT SUB- ZERO LOWS FOR LOW-LYING AREAS WHERE COLD-AIR
DRAINAGE EFFECTS OFF THE HIGH TERRAIN ARE MAXIMIZED. HIGH-TERRAIN
SHOULD REMAIN AT OR ABOVE ZERO.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
*/ SUNDAY MORNING INTO MIDDAY...

QUIET WEATHER. CLOUDS THICKENING AS WINDS INCREASE OUT OF THE S.
WILL SEE TEMPERATURES GRADUALLY MODERATE INTO THE MID- TO UPPER-20S.

*/ SUNDAY AFTERNOON INTO EARLY MONDAY MORNING...

1) HIGHLIGHTS...

 - SNOW SUNDAY AFTERNOON INTO MONDAY MORNING
 - GREATEST INTENSITY SUNDAY EVENING AND OVERNIGHT
 - 6+ INCH SNOWFALLS EXPECTED BUT EXACTLY WHERE REMAINS UNCERTAIN
 - ANNOYINGLY...FORECAST GUIDANCE CONTINUES TO WOBBLE

1) OVERVIEW...

BROAD ISENTROPIC OVER-RUNNING EVENT OF GULF MOISTURE ALONG THE 275-
295K SURFACES AMPLIFIED BY A N-STREAM IMPULSE DURING THE TIMEFRAME
POSSIBLY INVOKING AN AREA OF LOW PRESSURE THAT SKIRTS ALONG THE S-
COAST SUBSEQUENTLY ENHANCING LOW-LEVEL WIND PROFILE. LIGHT-MODERATE
SNOWFALL IS ANTICIPATED WITH LOCALLY HEAVIER AMOUNTS. THE INTENSE
PORTION OF SNOWFALL IS EXPECTED SUNDAY EVENING AND OVERNIGHT ENDING
EARLY MONDAY MORNING.

MODEL PREFERENCE GIVEN TO THE ECMWF/GFS/REGIONAL CANADIAN WHICH WILL
SERVE AS THE CONSENSUS OF GUIDANCE FOR THIS DISCUSSION. THE 28.12Z
NAM WAS CONSIDERED AN OUTLIER WITH ITS AGGRESSIVE-MODE AND SECONDARY
LOW DEVELOPMENT JUST OFFSHORE.

2) PRECIPITATION-TYPE...

EVALUATING THERMAL FIELDS...BLEND OF FORECAST CONSENSUS PUTS THE
-2C H925 ISOTHERM W-E ACROSS S-TIER OF CT/RI AND ACROSS SE MA WITH
THE 0C H85 ISOTHERM JUST S OF LONG-ISLAND AND NANTUCKET COASTLINES.
THE CONSENSUS OF 1000-850 MB CRITICAL THICKNESSES LAYS RIGHT ALONG
THE IMMEDIATE S-COAST OF LONG-ISLAND AND CAPE COD.

AN ALL SNOW-EVENT WHEN CONSIDERING DYNAMIC-COOLING/WETBULBING OF THE
LOW-LEVELS AHEAD OF THE EVENT. THERE IS PERHAPS A CHANCE OF A BRIEF
MIX-OVER TO RAIN/FREEZING RAIN ACROSS THE CAPE AND ISLANDS AS S-FLOW
AT THE SURFACE IS POSSIBLY ABLE TO NUDGE ABOVE-FREEZING TEMPERATURES
N. YET AS WE ARE IN A FROZEN TUNDRA...WITH ANY RAIN IT WOULD LIKELY
FREEZE ON SURFACES WHICH ARE QUITE COLD. THUS FREEZING RAIN PREVAILS
OVER RAIN IN THE FORECAST.

3) SNOWFALL...

FORECAST CONSENSUS OF A 0.3-0.6 N-S PRECIPITATION EVENT WITH A N-S
SNOW-TO-LIQUID RATIO GRADIENT RANGING FROM 15:1 TO 10:1 YIELDS HIGH-
END SNOW ADVISORY CRITERIA WITH SNOWFALL AMOUNTS RANGING ON AVERAGE
AROUND 3-6 INCHES. AREAS OF 6+ INCHES ARE EXPECTED...ESPECIALLY FROM
CENTRAL-CT E INTO SE-MA /INCLUDING THE UPPER-CAPE/. A CHALLENGE AND
A LOT OF UNCERTAINTY WITH RESPECT TO HEADLINES AND DECISION-MAKING.

EVALUATING LOW-LEVEL THERMAL PROFILES TOWARDS SNOW-TO-LIQUID RATIOS
DERIVED VIA A COBB-TECHNIQUE...WITH THE GREATEST LIFT OCCURRING
JUST BENEATH OR WITHIN THE DENDRITIC-GROWTH ZONE BASED ON A
CONSENSUS OF BUFKIT GFS PROFILES...ESPECIALLY IN HEAVIER- PRECIP
AREAS...BELIEVE THE SNOW WILL RANGE SOMEWHERE BETWEEN A WET AND
FLUFFY SNOW. SNOW PROPERTIES FROM FLUFFY TO WET LIKELY SIMILAR TO
THE N-S GRADIENT AS OUTLINED ABOVE.

4) HEADLINES...

HATE A WOBBLING FORECAST WHICH IS TYPICAL WITH SUCH SMALL EVENTS.
UNCERTAINTY DERIVES FROM LOW-LEVEL THERMAL PROFILES AND PRECIP
AMOUNTS. SURELY EXPECTING SNOW...BUT WITH ANY SHIFT N-S OF COLDER
AIR AND/OR PRECIPITATION AMOUNTS RESULTS IN AREAS SHIFTING FROM
ADVISORY TO WARNING...OR VICE VERSA. ENOUGH TO JUST PULL YOUR HAIR
OUT. THEN THERE IS THE TIMING OF THE SYSTEM THAT HAS SPED UP
SLIGHTLY. A SHORTER RESIDENCE TIME OF COURSE WOULD YIELD LESSER
SNOWFALL AMOUNTS. QUITE A CHALLENGING FORECAST RIGHT ON THE CUSP
OF HEADLINE THRESHOLDS.

THE EVENT DOES TAKE PLACE MAINLY FROM SUNDAY EVENING INTO THE EARLY
MORNING HOURS ON MONDAY DURING WHICH TIME THERE IS NOT MUCH TRAFFIC
ON THE ROAD. IS THIS A HIGH IMPACT EVENT THAT WARRANTS WARNINGS? A
QUESTION TO STRUGGLE WITH AS WARNINGS ARE NECESSARY WHEN WE ARE
CONFIDENT IN MEETING OR EXCEEDING 6+ INCH CRITERIA. YET THE QUESTION
IN FRONT OF US IS WHERE WILL THE HIGHER AMOUNTS OF SNOW FOCUS? HAVE
TO MAKE SOME SORT OF CALL...THE NEEDS OF THE MANY OUTWEIGH THE NEEDS
OF THE FEW.

ADVISORIES POSTED WHERE THERE IS HIGH CONFIDENCE OF SNOW BUT LIKELY
TO REMAIN BELOW THE 6-INCH THRESHOLD FOR WARNING. WATCHES CONTINUE
AND HAVE BEEN EXTENDED TO THE S-COAST TO COVER FOR THE UNCERTAINTY
OF THE AREA EITHER FALLING WITHIN OR IN EXCESS OF ADVISORY-LEVEL
SNOWS. AGAIN...6+ INCH AMOUNTS ARE ANTICIPATED BUT EXACTLY WHERE IS
UNCERTAIN.

5) CLOSING NOTES...

SOME CONCERN FOR THE EARLY MONDAY MORNING COMMUTE FOR E/SE MA AND
RI. WHILE MOST OF THE SNOW IS EXPECTED TO BE IMMEDIATELY OFFSHORE
WITH SUNRISE MONDAY...COMMUTERS COULD ENCOUNTER SLICK AND SLIPPERY
ROAD CONDITIONS. SNOW COULD POSSIBLY LINGER OVER SE MA SO THERE IS
THE POTENTIAL FOR REDUCED VISIBILITIES.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
BIG PICTURE... THE BROAD UPPER FLOW SHOWS A RIDGE IN THE EAST AND
TROUGH IN THE WEST WITH A WEST SOUTHWEST FLOW FROM THE PLAINS TO THE
EASTERN USA COAST. WITHIN THIS FLOW ARE BOTH NORTHERN AND SOUTHERN
STREAMS AT THE START OF THE WEEK. THE WESTERN TROUGH MIGRATES EAST
DURING THE MIDWEEK AT WHICH TIME THE TWO STREAMS MERGE TO FORM A 140-
160 KT UPPER JET FEEDING NORTHEAST INTO THE GREAT LAKES AND ST
LAWRENCE VALLEY. THIS JET LINGERS OVER OR NEAR NEW ENGLAND THURSDAY-
FRIDAY BEFORE MOVING OFF. THE WESTERN TROUGH MOVES ACROSS NEW
ENGLAND BY THE END OF THE WEEK.

DAILIES...

MONDAY... SUNDAY STORM MOVES OFF PAST NOVA SCOTIA WHILE THE
SUPPORTING UPPER SHORTWAVE AND COLD POOL SWING ACROSS NEW ENGLAND.
THE COOLEST AIR ALOFT IS IN NORTHERN NEW ENGLAND WHILE LEFTOVER
MOISTURE LINGERS BELOW 800 MB THROUGH THE DAY. THE GFS IS FASTER
THAN THE ECMWF IN BRINGING RISING PRESSURE TO THE REGION BUT HAVE 1
MB/HOUR RISES HERE BY EVENING. PUT TOGETHER...EXPECT A CLEARING
TREND BUT WITH LEFTOVER CLOUDS ESPECIALLY NORTH OF THE MASS PIKE.
SUSTAINED NORTHWEST WINDS SHOULD RISE TO 15-20 KTS. MIXING REACHES
TO AT LEAST 850 MB AND POSSIBLY A LITTLE HIGHER...WHICH SUPPORTS
GUSTS TO AT LEAST 30 KNOTS AND POSSIBLY 35 KNOTS. TEMPS AT 850 MB
WILL BE -11C TO -14C...MIXING THIS TO THE SURFACE WOULD SUPPORT MAX
SFC TEMPS IN THE 30S. MIN TEMPERATURES UPSTREAM THIS MORNING WERE IN
THE SINGLE NUMBERS WITH A FEW SPOTS BELOW ZERO. WITH LIGHT PRESSURE
GRADIENT ESP IN THE WEST...WE TENDED A FEW DEGREES COOLER THAN
CONSENSUS.

TUESDAY-WEDNESDAY... HIGH PRESSURE IN CONTROL MUCH OF TUESDAY BUT
MOVING OFFSHORE DURING THE AFTERNOON. CROSS SECTIONS SHOW INCREASING
MOISTURE AT MID AND HIGH CLOUD LEVEL...SO INCREASING HIGH CLOUDS.
SYSTEM MOVING INTO THE GREAT LAKES SPREADS PCPN INTO NEW YORK...BUT
WARM ADVECTION LIFT REMAINS MOSTLY TO OUR WEST THROUGH THE
AFTERNOON. SOME LIFT FORECAST AT 290K /ABOUT 730 MB AT THE TIME/ BUT
NONE BELOW THAT. MEANWHILE DEWPOINTS IN THE SINGLE NUMBERS PROGRESS
INTO THE TEENS DURING THE DAY...BUT ENOUGH OF A TEMP/DEWPOINT SPREAD
TO SLOW THE ADVANCE OF ANY PCPN FROM THE CLOUDS BY A FEW HOURS.

WARM ADVECTION LIFT MUCH OF THE NIGHT SUPPORTS THE IDEA OF PCPN.
TEMPERATURES START COLD DURING THE EVENING BUT SHOULD RISE
OVERNIGHT. THE QUESTION REMAINS AS TO HOW HIGH THEY WILL CLIMB. EVEN
WITH THE SURFACE SYSTEM TRACKING UP THE ST LAWRENCE VALLEY THERE IS
COLD GROUND AND A COLD SNOWPACK. THIS WOULD ALLOW THE WARMER TEMPS
TO SCREAM OVERHEAD WHILE THE IMMEDIATE SURFACE REMAINS SEVERAL
DEGREES COLDER. WE TRIMMED TEMPS BACK A LITTLE FROM MODEL
VALUES...BUT LOW CONFIDENCE AT THIS TIME DUE TO THE POTENTIAL THAT
SURFACE TEMPS COULD REMAIN IN THE 30S.

QPF FORECASTS RANGE FROM 0.50 TO 1.00 INCHES WITH THE HIGHER AMOUNTS
TENDING TOWARD THE SOUTH COAST. THIS POINTS TO A MESSY STORM WITH
INITIAL SNOW ACCUMS OF SEVERAL INCHES FOLLOWED BY A CHANGE TO
MEASUREABLE ICE ACCUMULATION AND THEN A CHANGE TO RAIN WITH
POTENTIAL FOR POOR DRAINAGE FLOODING IN BETWEEN THE SNOW BANKS.

THE COLD FRONT SHOULD MOVE THROUGH DURING THE AFTERNOON/EVENING WITH
A SHIFT TO NORTHWEST WINDS. THIS WILL CHANGE THE PCPN BACK TO SNOW
BEFORE TAPERING OFF.

THURSDAY...DIFERENCES IN THE GFS AND ECMWF IN HANDING THE UPPER JET.
THE ECMWF MOVES THE JET OFFSHORE AND PUTS SOUTHERN NEW ENGLAND
INTO SUBSIDENCE. THE GFS MAINTAINS THE JET OVERHEAD WITH OUR AREA
IN THE RIGHT ENTRANCE REGION. THE FIRST SCENARIO ENDS THE PCPN AND
COOLS THE AIR. THE SECOND SCENARIO WOULD SUPPORT LIFT AND GENERATE
WAVES ALONG THE DEPARTING COLD FRONT...MAINTAINING A CHANCE OF
SNOW OVER AT LEAST SOUTHERN PARTS OF OUR AREA. OUR THURSDAY
FORECAST TENDS TOWARD THE LATTER FOR NOW.

FRIDAY-SATURDAY... HIGH PRESSURE BUILDS OVER THE REGION THURSDAY
NIGHT AND FRIDAY WITH CLEARING SKIES AND A BRIEF PERIOD OF COLD AIR.
TEMPS ALOFT TREND UP ABOUT 10C ON SATURDAY SUGGESTING LESS CHILL AT
THE SURFACE. ANOTHER COLD FRONT APPROACHES THE ST LAWRENCE VALLEY
AND COULD SPREAD SOME CLOUDS INTO OUR AREA SATURDAY
AFTERNOON/EVENING. BUT PCPN CHANCES LOOK SMALL.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /THROUGH MONDAY MORNING/...

TONIGHT THROUGH SUNDAY MIDDAY...HIGH CONFIDENCE.

VFR. LOWERING AND THICKENING CLOUDS SUNDAY MORNING INTO MIDDAY.

SUNDAY AFTERNOON INTO MONDAY MORNING...MODERATE CONFIDENCE.

SNOW OVERSPREADS THE REGION W-E. CIGS/VSBYS DETERIORATE TO MVFR-
IFR BY EARLY EVENING...WIDESPREAD IFR-LIFR SUNDAY NIGHT. SN TO MIX
WITH OR CHANGE TO FZRA ACROSS OFFSHORE ISLAND TERMINALS OVERNIGHT.
PRECIP ENDS W-E TOWARD DAYBREAK MONDAY....CONDITIONS IMPROVE.

KBOS TAF...MODERATE CONFIDENCE. TRENDS CERTAIN BUT NOT SO MUCH THE
ACTUAL TIMING OF IMPACTS.

KBDL TAF...MODERATE CONFIDENCE. TRENDS CERTAIN BUT NOT SO MUCH
THE ACTUAL TIMING OF IMPACTS.

OUTLOOK...MONDAY THROUGH THURSDAY...

MONDAY... HIGH CONFIDENCE. SOME IFR/MVFR IN SNOW EARLY MORNING BUT
OTHERWISE CONDITIONS WILL IMPROVE TO VFR DURING THE MORNING.
NORTHWEST WINDS WILL INCREASE WITH GUSTS AROUND 30 KNOTS BY MIDDAY.
VFR AND DIMINISHING WIND MONDAY NIGHT.

TUESDAY...MODERATE CONFIDENCE. VFR DURING THE DAY WITH INCREASING
SKY COVER. MVFR TUESDAY EVENING BECOMING IFR/LIFR OVERNIGHT IN
DEVELOPING SNOW AND FREEZING RAIN.

WEDNESDAY...MODERATE CONFIDENCE. IFR/LIFR IN RAIN AND FREEZING RAIN.

THURSDAY...LOW CONFIDENCE. VFR NORTH OF A HFD-BOS LINE. MVFR CIGS
AND AREAS OF MVFR/IFR VSBYS IN SNOW.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /THROUGH MONDAY MORNING/...HIGH CONFIDENCE.

HIGH PRESSURE NEARBY WILL KEEP WINDS/SEAS WELL BELOW SMALL CRAFT
ADVISORY THRESHOLDS INTO SUNDAY MORNING. A WEAK WAVE OF LOW
PRESSURE MOVES ACROSS THE WATERS LATE SUNDAY INTO SUNDAY NIGHT...
BUT WEAK PRESSURE GRADIENT SHOULD KEEP WINDS/SEAS BELOW SMALL
CRAFT THRESHOLDS.

OUTLOOK...MONDAY THROUGH THURSDAY..MODERATE CONFIDENCE.

MONDAY...WEST TO NORTHWEST WINDS INCREASE WITH FREQUENT GUSTS TO
GALE FORCE ESPECIALLY AWAY FROM THE NEARSHORE. THIS COULD GENERATE
SOME LIGHT FREEZING SPRAY ESPECIALLY EARLY MONDAY NIGHT. SEAS 5
TO 10 FEET. WINDS AND SEAS DIMINISH MONDAY NIGHT. A GALE WARNING
MAY BE NEEDED.

TUESDAY... LINGERING 5 FOOT SEAS ON THE OUTER WATERS BUT DIMINISHING
DURING THE MORNING.  WINDS AND SEAS INCREASE AGAIN TUESDAY NIGHT
AFTER MIDNIGHT AHEAD OF A GREAT LAKES COLD FRONT. SOUTH WINDS WILL
APPROACH 25 KNOTS WITH SEAS BUILDING TO 5 TO 8 FEET. VSBYS WILL
BE REDUCED IN SNOW CHANGING TO RAIN.

WEDNESDAY...SOUTHWEST WINDS WITH GUSTS 25-30 KNOTS.  SEAS BUILDING
TO 6 TO 12 FEET. REDUCED VSBYS IN RAIN. A SMALL CRAFT ADVISORY MAY
BE NEEDED.

THURSDAY...NORTHWEST WINDS WILL GUST TO 25 KNOTS...AND SEAS 5 TO 8
FEET. BOTH SHOULD DIMINISH TOWARD EVENING.  A SMALL CRAFT ADVISORY
MAY BE NEEDED.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY
     MORNING FOR CTZ002>004.
MA...WINTER WEATHER ADVISORY FROM NOON SUNDAY TO 7 AM EST MONDAY
     FOR MAZ002>008-010-014-023-024-026.
     WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY
     MORNING FOR MAZ009-011>013-015>022.
RI...WINTER WEATHER ADVISORY FROM NOON SUNDAY TO 7 AM EST MONDAY
     FOR RIZ008.
     WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY
     MORNING FOR RIZ001>007.
MARINE...NONE.

&&

$$
SYNOPSIS...WTB/SIPPRELL
NEAR TERM...WTB/SIPPRELL
SHORT TERM...SIPPRELL
LONG TERM...WTB
AVIATION...WTB/SIPPRELL
MARINE...WTB/SIPPRELL




000
FXUS61 KBOX 010012
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
712 PM EST SAT FEB 28 2015

.SYNOPSIS...
A FAST MOVING LOW PRESSURE SYSTEM WILL BRING ACCUMULATING SNOW TO
THE REGION LATE SUNDAY INTO SUNDAY NIGHT...WITH THE HIGHEST AMOUNTS
EXPECTED SOUTH OF THE MASSACHUSETTS TURNPIKE AND AWAY FROM THE
IMMEDIATE SOUTH COAST. HIGH PRESSURE BRINGS DRY COLD AIR FOR THE
EARLY WEEK. LOW PRESSURE FROM NORTHERN CANADA AND ASSOCIATED LOW
FORMING OVER THE PLAINS MONDAY WILL MERGE...THEN PASS WEST AND
NORTH OF NEW ENGLAND. THIS WILL SWING A COLD FRONT ACROSS THE
REGION ON WEDNESDAY. DRY AND COLD WEATHER RETURNS FOR THE END OF
THE WEEK.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...

CLEAR SKIES AND LIGHT WIND WILL MEAN GOOD RADIATIONAL COOLING. MID
TO HIGH CLOUDS OVER OHIO EXTRAPOLATE TO WESTERN NEW ENGLAND AROUND
4 AM AND EASTERN SECTIONS AROUND 6 AM. DEW POINTS RANGE FROM
BELOW ZERO IN THE INTERIOR TO AROUND 10 ALONG THE SOUTH COAST.

LOOKING AT SUB- ZERO LOWS FOR LOW-LYING AREAS WHERE COLD-AIR
DRAINAGE EFFECTS OFF THE HIGH TERRAIN ARE MAXIMIZED. HIGH-TERRAIN
SHOULD REMAIN AT OR ABOVE ZERO.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
*/ SUNDAY MORNING INTO MIDDAY...

QUIET WEATHER. CLOUDS THICKENING AS WINDS INCREASE OUT OF THE S.
WILL SEE TEMPERATURES GRADUALLY MODERATE INTO THE MID- TO UPPER-20S.

*/ SUNDAY AFTERNOON INTO EARLY MONDAY MORNING...

1) HIGHLIGHTS...

 - SNOW SUNDAY AFTERNOON INTO MONDAY MORNING
 - GREATEST INTENSITY SUNDAY EVENING AND OVERNIGHT
 - 6+ INCH SNOWFALLS EXPECTED BUT EXACTLY WHERE REMAINS UNCERTAIN
 - ANNOYINGLY...FORECAST GUIDANCE CONTINUES TO WOBBLE

1) OVERVIEW...

BROAD ISENTROPIC OVER-RUNNING EVENT OF GULF MOISTURE ALONG THE 275-
295K SURFACES AMPLIFIED BY A N-STREAM IMPULSE DURING THE TIMEFRAME
POSSIBLY INVOKING AN AREA OF LOW PRESSURE THAT SKIRTS ALONG THE S-
COAST SUBSEQUENTLY ENHANCING LOW-LEVEL WIND PROFILE. LIGHT-MODERATE
SNOWFALL IS ANTICIPATED WITH LOCALLY HEAVIER AMOUNTS. THE INTENSE
PORTION OF SNOWFALL IS EXPECTED SUNDAY EVENING AND OVERNIGHT ENDING
EARLY MONDAY MORNING.

MODEL PREFERENCE GIVEN TO THE ECMWF/GFS/REGIONAL CANADIAN WHICH WILL
SERVE AS THE CONSENSUS OF GUIDANCE FOR THIS DISCUSSION. THE 28.12Z
NAM WAS CONSIDERED AN OUTLIER WITH ITS AGGRESSIVE-MODE AND SECONDARY
LOW DEVELOPMENT JUST OFFSHORE.

2) PRECIPITATION-TYPE...

EVALUATING THERMAL FIELDS...BLEND OF FORECAST CONSENSUS PUTS THE
-2C H925 ISOTHERM W-E ACROSS S-TIER OF CT/RI AND ACROSS SE MA WITH
THE 0C H85 ISOTHERM JUST S OF LONG-ISLAND AND NANTUCKET COASTLINES.
THE CONSENSUS OF 1000-850 MB CRITICAL THICKNESSES LAYS RIGHT ALONG
THE IMMEDIATE S-COAST OF LONG-ISLAND AND CAPE COD.

AN ALL SNOW-EVENT WHEN CONSIDERING DYNAMIC-COOLING/WETBULBING OF THE
LOW-LEVELS AHEAD OF THE EVENT. THERE IS PERHAPS A CHANCE OF A BRIEF
MIX-OVER TO RAIN/FREEZING RAIN ACROSS THE CAPE AND ISLANDS AS S-FLOW
AT THE SURFACE IS POSSIBLY ABLE TO NUDGE ABOVE-FREEZING TEMPERATURES
N. YET AS WE ARE IN A FROZEN TUNDRA...WITH ANY RAIN IT WOULD LIKELY
FREEZE ON SURFACES WHICH ARE QUITE COLD. THUS FREEZING RAIN PREVAILS
OVER RAIN IN THE FORECAST.

3) SNOWFALL...

FORECAST CONSENSUS OF A 0.3-0.6 N-S PRECIPITATION EVENT WITH A N-S
SNOW-TO-LIQUID RATIO GRADIENT RANGING FROM 15:1 TO 10:1 YIELDS HIGH-
END SNOW ADVISORY CRITERIA WITH SNOWFALL AMOUNTS RANGING ON AVERAGE
AROUND 3-6 INCHES. AREAS OF 6+ INCHES ARE EXPECTED...ESPECIALLY FROM
CENTRAL-CT E INTO SE-MA /INCLUDING THE UPPER-CAPE/. A CHALLENGE AND
A LOT OF UNCERTAINTY WITH RESPECT TO HEADLINES AND DECISION-MAKING.

EVALUATING LOW-LEVEL THERMAL PROFILES TOWARDS SNOW-TO-LIQUID RATIOS
DERIVED VIA A COBB-TECHNIQUE...WITH THE GREATEST LIFT OCCURRING
JUST BENEATH OR WITHIN THE DENDRITIC-GROWTH ZONE BASED ON A
CONSENSUS OF BUFKIT GFS PROFILES...ESPECIALLY IN HEAVIER- PRECIP
AREAS...BELIEVE THE SNOW WILL RANGE SOMEWHERE BETWEEN A WET AND
FLUFFY SNOW. SNOW PROPERTIES FROM FLUFFY TO WET LIKELY SIMILAR TO
THE N-S GRADIENT AS OUTLINED ABOVE.

4) HEADLINES...

HATE A WOBBLING FORECAST WHICH IS TYPICAL WITH SUCH SMALL EVENTS.
UNCERTAINTY DERIVES FROM LOW-LEVEL THERMAL PROFILES AND PRECIP
AMOUNTS. SURELY EXPECTING SNOW...BUT WITH ANY SHIFT N-S OF COLDER
AIR AND/OR PRECIPITATION AMOUNTS RESULTS IN AREAS SHIFTING FROM
ADVISORY TO WARNING...OR VICE VERSA. ENOUGH TO JUST PULL YOUR HAIR
OUT. THEN THERE IS THE TIMING OF THE SYSTEM THAT HAS SPED UP
SLIGHTLY. A SHORTER RESIDENCE TIME OF COURSE WOULD YIELD LESSER
SNOWFALL AMOUNTS. QUITE A CHALLENGING FORECAST RIGHT ON THE CUSP
OF HEADLINE THRESHOLDS.

THE EVENT DOES TAKE PLACE MAINLY FROM SUNDAY EVENING INTO THE EARLY
MORNING HOURS ON MONDAY DURING WHICH TIME THERE IS NOT MUCH TRAFFIC
ON THE ROAD. IS THIS A HIGH IMPACT EVENT THAT WARRANTS WARNINGS? A
QUESTION TO STRUGGLE WITH AS WARNINGS ARE NECESSARY WHEN WE ARE
CONFIDENT IN MEETING OR EXCEEDING 6+ INCH CRITERIA. YET THE QUESTION
IN FRONT OF US IS WHERE WILL THE HIGHER AMOUNTS OF SNOW FOCUS? HAVE
TO MAKE SOME SORT OF CALL...THE NEEDS OF THE MANY OUTWEIGH THE NEEDS
OF THE FEW.

ADVISORIES POSTED WHERE THERE IS HIGH CONFIDENCE OF SNOW BUT LIKELY
TO REMAIN BELOW THE 6-INCH THRESHOLD FOR WARNING. WATCHES CONTINUE
AND HAVE BEEN EXTENDED TO THE S-COAST TO COVER FOR THE UNCERTAINTY
OF THE AREA EITHER FALLING WITHIN OR IN EXCESS OF ADVISORY-LEVEL
SNOWS. AGAIN...6+ INCH AMOUNTS ARE ANTICIPATED BUT EXACTLY WHERE IS
UNCERTAIN.

5) CLOSING NOTES...

SOME CONCERN FOR THE EARLY MONDAY MORNING COMMUTE FOR E/SE MA AND
RI. WHILE MOST OF THE SNOW IS EXPECTED TO BE IMMEDIATELY OFFSHORE
WITH SUNRISE MONDAY...COMMUTERS COULD ENCOUNTER SLICK AND SLIPPERY
ROAD CONDITIONS. SNOW COULD POSSIBLY LINGER OVER SE MA SO THERE IS
THE POTENTIAL FOR REDUCED VISIBILITIES.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
BIG PICTURE... THE BROAD UPPER FLOW SHOWS A RIDGE IN THE EAST AND
TROUGH IN THE WEST WITH A WEST SOUTHWEST FLOW FROM THE PLAINS TO THE
EASTERN USA COAST. WITHIN THIS FLOW ARE BOTH NORTHERN AND SOUTHERN
STREAMS AT THE START OF THE WEEK. THE WESTERN TROUGH MIGRATES EAST
DURING THE MIDWEEK AT WHICH TIME THE TWO STREAMS MERGE TO FORM A 140-
160 KT UPPER JET FEEDING NORTHEAST INTO THE GREAT LAKES AND ST
LAWRENCE VALLEY. THIS JET LINGERS OVER OR NEAR NEW ENGLAND THURSDAY-
FRIDAY BEFORE MOVING OFF. THE WESTERN TROUGH MOVES ACROSS NEW
ENGLAND BY THE END OF THE WEEK.

DAILIES...

MONDAY... SUNDAY STORM MOVES OFF PAST NOVA SCOTIA WHILE THE
SUPPORTING UPPER SHORTWAVE AND COLD POOL SWING ACROSS NEW ENGLAND.
THE COOLEST AIR ALOFT IS IN NORTHERN NEW ENGLAND WHILE LEFTOVER
MOISTURE LINGERS BELOW 800 MB THROUGH THE DAY. THE GFS IS FASTER
THAN THE ECMWF IN BRINGING RISING PRESSURE TO THE REGION BUT HAVE 1
MB/HOUR RISES HERE BY EVENING. PUT TOGETHER...EXPECT A CLEARING
TREND BUT WITH LEFTOVER CLOUDS ESPECIALLY NORTH OF THE MASS PIKE.
SUSTAINED NORTHWEST WINDS SHOULD RISE TO 15-20 KTS. MIXING REACHES
TO AT LEAST 850 MB AND POSSIBLY A LITTLE HIGHER...WHICH SUPPORTS
GUSTS TO AT LEAST 30 KNOTS AND POSSIBLY 35 KNOTS. TEMPS AT 850 MB
WILL BE -11C TO -14C...MIXING THIS TO THE SURFACE WOULD SUPPORT MAX
SFC TEMPS IN THE 30S. MIN TEMPERATURES UPSTREAM THIS MORNING WERE IN
THE SINGLE NUMBERS WITH A FEW SPOTS BELOW ZERO. WITH LIGHT PRESSURE
GRADIENT ESP IN THE WEST...WE TENDED A FEW DEGREES COOLER THAN
CONSENSUS.

TUESDAY-WEDNESDAY... HIGH PRESSURE IN CONTROL MUCH OF TUESDAY BUT
MOVING OFFSHORE DURING THE AFTERNOON. CROSS SECTIONS SHOW INCREASING
MOISTURE AT MID AND HIGH CLOUD LEVEL...SO INCREASING HIGH CLOUDS.
SYSTEM MOVING INTO THE GREAT LAKES SPREADS PCPN INTO NEW YORK...BUT
WARM ADVECTION LIFT REMAINS MOSTLY TO OUR WEST THROUGH THE
AFTERNOON. SOME LIFT FORECAST AT 290K /ABOUT 730 MB AT THE TIME/ BUT
NONE BELOW THAT. MEANWHILE DEWPOINTS IN THE SINGLE NUMBERS PROGRESS
INTO THE TEENS DURING THE DAY...BUT ENOUGH OF A TEMP/DEWPOINT SPREAD
TO SLOW THE ADVANCE OF ANY PCPN FROM THE CLOUDS BY A FEW HOURS.

WARM ADVECTION LIFT MUCH OF THE NIGHT SUPPORTS THE IDEA OF PCPN.
TEMPERATURES START COLD DURING THE EVENING BUT SHOULD RISE
OVERNIGHT. THE QUESTION REMAINS AS TO HOW HIGH THEY WILL CLIMB. EVEN
WITH THE SURFACE SYSTEM TRACKING UP THE ST LAWRENCE VALLEY THERE IS
COLD GROUND AND A COLD SNOWPACK. THIS WOULD ALLOW THE WARMER TEMPS
TO SCREAM OVERHEAD WHILE THE IMMEDIATE SURFACE REMAINS SEVERAL
DEGREES COLDER. WE TRIMMED TEMPS BACK A LITTLE FROM MODEL
VALUES...BUT LOW CONFIDENCE AT THIS TIME DUE TO THE POTENTIAL THAT
SURFACE TEMPS COULD REMAIN IN THE 30S.

QPF FORECASTS RANGE FROM 0.50 TO 1.00 INCHES WITH THE HIGHER AMOUNTS
TENDING TOWARD THE SOUTH COAST. THIS POINTS TO A MESSY STORM WITH
INITIAL SNOW ACCUMS OF SEVERAL INCHES FOLLOWED BY A CHANGE TO
MEASUREABLE ICE ACCUMULATION AND THEN A CHANGE TO RAIN WITH
POTENTIAL FOR POOR DRAINAGE FLOODING IN BETWEEN THE SNOW BANKS.

THE COLD FRONT SHOULD MOVE THROUGH DURING THE AFTERNOON/EVENING WITH
A SHIFT TO NORTHWEST WINDS. THIS WILL CHANGE THE PCPN BACK TO SNOW
BEFORE TAPERING OFF.

THURSDAY...DIFERENCES IN THE GFS AND ECMWF IN HANDING THE UPPER JET.
THE ECMWF MOVES THE JET OFFSHORE AND PUTS SOUTHERN NEW ENGLAND
INTO SUBSIDENCE. THE GFS MAINTAINS THE JET OVERHEAD WITH OUR AREA
IN THE RIGHT ENTRANCE REGION. THE FIRST SCENARIO ENDS THE PCPN AND
COOLS THE AIR. THE SECOND SCENARIO WOULD SUPPORT LIFT AND GENERATE
WAVES ALONG THE DEPARTING COLD FRONT...MAINTAINING A CHANCE OF
SNOW OVER AT LEAST SOUTHERN PARTS OF OUR AREA. OUR THURSDAY
FORECAST TENDS TOWARD THE LATTER FOR NOW.

FRIDAY-SATURDAY... HIGH PRESSURE BUILDS OVER THE REGION THURSDAY
NIGHT AND FRIDAY WITH CLEARING SKIES AND A BRIEF PERIOD OF COLD AIR.
TEMPS ALOFT TREND UP ABOUT 10C ON SATURDAY SUGGESTING LESS CHILL AT
THE SURFACE. ANOTHER COLD FRONT APPROACHES THE ST LAWRENCE VALLEY
AND COULD SPREAD SOME CLOUDS INTO OUR AREA SATURDAY
AFTERNOON/EVENING. BUT PCPN CHANCES LOOK SMALL.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /THROUGH MONDAY MORNING/...

TONIGHT THROUGH SUNDAY MIDDAY...HIGH CONFIDENCE.

VFR. LOWERING AND THICKENING CLOUDS SUNDAY MORNING INTO MIDDAY.

SUNDAY AFTERNOON INTO MONDAY MORNING...MODERATE CONFIDENCE.

SNOW OVERSPREADS THE REGION W-E. CIGS/VSBYS DETERIORATE TO MVFR-
IFR BY EARLY EVENING...WIDESPREAD IFR-LIFR SUNDAY NIGHT. SN TO MIX
WITH OR CHANGE TO FZRA ACROSS OFFSHORE ISLAND TERMINALS OVERNIGHT.
PRECIP ENDS W-E TOWARD DAYBREAK MONDAY....CONDITIONS IMPROVE.

KBOS TAF...MODERATE CONFIDENCE. TRENDS CERTAIN BUT NOT SO MUCH THE
ACTUAL TIMING OF IMPACTS.

KBDL TAF...MODERATE CONFIDENCE. TRENDS CERTAIN BUT NOT SO MUCH
THE ACTUAL TIMING OF IMPACTS.

OUTLOOK...MONDAY THROUGH THURSDAY...

MONDAY... HIGH CONFIDENCE. SOME IFR/MVFR IN SNOW EARLY MORNING BUT
OTHERWISE CONDITIONS WILL IMPROVE TO VFR DURING THE MORNING.
NORTHWEST WINDS WILL INCREASE WITH GUSTS AROUND 30 KNOTS BY MIDDAY.
VFR AND DIMINISHING WIND MONDAY NIGHT.

TUESDAY...MODERATE CONFIDENCE. VFR DURING THE DAY WITH INCREASING
SKY COVER. MVFR TUESDAY EVENING BECOMING IFR/LIFR OVERNIGHT IN
DEVELOPING SNOW AND FREEZING RAIN.

WEDNESDAY...MODERATE CONFIDENCE. IFR/LIFR IN RAIN AND FREEZING RAIN.

THURSDAY...LOW CONFIDENCE. VFR NORTH OF A HFD-BOS LINE. MVFR CIGS
AND AREAS OF MVFR/IFR VSBYS IN SNOW.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /THROUGH MONDAY MORNING/...HIGH CONFIDENCE.

HIGH PRESSURE NEARBY WILL KEEP WINDS/SEAS WELL BELOW SMALL CRAFT
ADVISORY THRESHOLDS INTO SUNDAY MORNING. A WEAK WAVE OF LOW
PRESSURE MOVES ACROSS THE WATERS LATE SUNDAY INTO SUNDAY NIGHT...
BUT WEAK PRESSURE GRADIENT SHOULD KEEP WINDS/SEAS BELOW SMALL
CRAFT THRESHOLDS.

OUTLOOK...MONDAY THROUGH THURSDAY..MODERATE CONFIDENCE.

MONDAY...WEST TO NORTHWEST WINDS INCREASE WITH FREQUENT GUSTS TO
GALE FORCE ESPECIALLY AWAY FROM THE NEARSHORE. THIS COULD GENERATE
SOME LIGHT FREEZING SPRAY ESPECIALLY EARLY MONDAY NIGHT. SEAS 5
TO 10 FEET. WINDS AND SEAS DIMINISH MONDAY NIGHT. A GALE WARNING
MAY BE NEEDED.

TUESDAY... LINGERING 5 FOOT SEAS ON THE OUTER WATERS BUT DIMINISHING
DURING THE MORNING.  WINDS AND SEAS INCREASE AGAIN TUESDAY NIGHT
AFTER MIDNIGHT AHEAD OF A GREAT LAKES COLD FRONT. SOUTH WINDS WILL
APPROACH 25 KNOTS WITH SEAS BUILDING TO 5 TO 8 FEET. VSBYS WILL
BE REDUCED IN SNOW CHANGING TO RAIN.

WEDNESDAY...SOUTHWEST WINDS WITH GUSTS 25-30 KNOTS.  SEAS BUILDING
TO 6 TO 12 FEET. REDUCED VSBYS IN RAIN. A SMALL CRAFT ADVISORY MAY
BE NEEDED.

THURSDAY...NORTHWEST WINDS WILL GUST TO 25 KNOTS...AND SEAS 5 TO 8
FEET. BOTH SHOULD DIMINISH TOWARD EVENING.  A SMALL CRAFT ADVISORY
MAY BE NEEDED.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY
     MORNING FOR CTZ002>004.
MA...WINTER WEATHER ADVISORY FROM NOON SUNDAY TO 7 AM EST MONDAY
     FOR MAZ002>008-010-014-023-024-026.
     WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY
     MORNING FOR MAZ009-011>013-015>022.
RI...WINTER WEATHER ADVISORY FROM NOON SUNDAY TO 7 AM EST MONDAY
     FOR RIZ008.
     WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY
     MORNING FOR RIZ001>007.
MARINE...NONE.

&&

$$
SYNOPSIS...WTB/SIPPRELL
NEAR TERM...WTB/SIPPRELL
SHORT TERM...SIPPRELL
LONG TERM...WTB
AVIATION...WTB/SIPPRELL
MARINE...WTB/SIPPRELL



000
FXUS61 KBOX 282100
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
400 PM EST SAT FEB 28 2015

.SYNOPSIS...
A FAST MOVING LOW PRESSURE SYSTEM WILL BRING ACCUMULATING SNOW TO
THE REGION LATE SUNDAY INTO SUNDAY NIGHT...WITH THE HIGHEST AMOUNTS
EXPECTED SOUTH OF THE MASSACHUSETTS TURNPIKE AND AWAY FROM THE
IMMEDIATE SOUTH COAST. HIGH PRESSURE BRINGS DRY COLD AIR FOR THE
EARLY WEEK. LOW PRESSURE FROM NORTHERN CANADA AND ASSOCIATED LOW
FORMING OVER THE PLAINS MONDAY WILL MERGE...THEN PASS WEST AND
NORTH OF NEW ENGLAND. THIS WILL SWING A COLD FRONT ACROSS THE
REGION ON WEDNESDAY. DRY AND COLD WEATHER RETURNS FOR THE END OF
THE WEEK.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
INTO THIS EVENING...

HIGH PRESSURE PUSHING E INTO THE REGION. TEMPERATURES EXPECTED TO
QUICKLY DROP WITH MOSTLY CLEAR CONDITIONS AND LIGHT WINDS.

TONIGHT...

COLD. CONDITIONS WILL BE JUST RIGHT TO ALLOW FOR GOOD RADIATIONAL
COOLING...ESPECIALLY TO THE E WHERE THE IMPACT OF INCREASING MID- TO
HIGH-CLOUDS LATE IN THE PERIOD WILL BE LESS. LOOKING AT SUB-ZERO
LOWS FOR LOW-LYING AREAS WHERE COLD-AIR DRAINAGE EFFECTS OFF THE
HIGH TERRAIN ARE MAXIMIZED. HIGH-TERRAIN SHOULD REMAIN AT OR ABOVE
ZERO.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
*/ SUNDAY MORNING INTO MIDDAY...

QUIET WEATHER. CLOUDS THICKENING AS WINDS INCREASE OUT OF THE S.
WILL SEE TEMPERATURES GRADUALLY MODERATE INTO THE MID- TO UPPER-20S.

*/ SUNDAY AFTERNOON INTO EARLY MONDAY MORNING...

1) HIGHLIGHTS...

 - SNOW SUNDAY AFTERNOON INTO MONDAY MORNING
 - GREATEST INTENSITY SUNDAY EVENING AND OVERNIGHT
 - 6+ INCH SNOWFALLS EXPECTED BUT EXACTLY WHERE REMAINS UNCERTAIN
 - ANNOYINGLY...FORECAST GUIDANCE CONTINUES TO WOBBLE

1) OVERVIEW...

BROAD ISENTROPIC OVER-RUNNING EVENT OF GULF MOISTURE ALONG THE 275-
295K SURFACES AMPLIFIED BY A N-STREAM IMPULSE DURING THE TIMEFRAME
POSSIBLY INVOKING AN AREA OF LOW PRESSURE THAT SKIRTS ALONG THE S-
COAST SUBSEQUENTLY ENHANCING LOW-LEVEL WIND PROFILE. LIGHT-MODERATE
SNOWFALL IS ANTICIPATED WITH LOCALLY HEAVIER AMOUNTS. THE INTENSE
PORTION OF SNOWFALL IS EXPECTED SUNDAY EVENING AND OVERNIGHT ENDING
EARLY MONDAY MORNING.

MODEL PREFERENCE GIVEN TO THE ECMWF/GFS/REGIONAL CANADIAN WHICH WILL
SERVE AS THE CONSENSUS OF GUIDANCE FOR THIS DISCUSSION. THE 28.12Z
NAM WAS CONSIDERED AN OUTLIER WITH ITS AGGRESSIVE-MODE AND SECONDARY
LOW DEVELOPMENT JUST OFFSHORE.

2) PRECIPITATION-TYPE...

EVALUATING THERMAL FIELDS...BLEND OF FORECAST CONSENSUS PUTS THE
-2C H925 ISOTHERM W-E ACROSS S-TIER OF CT/RI AND ACROSS SE MA WITH
THE 0C H85 ISOTHERM JUST S OF LONG-ISLAND AND NANTUCKET COASTLINES.
THE CONSENSUS OF 1000-850 MB CRITICAL THICKNESSES LAYS RIGHT ALONG
THE IMMEDIATE S-COAST OF LONG-ISLAND AND CAPE COD.

AN ALL SNOW-EVENT WHEN CONSIDERING DYNAMIC-COOLING/WETBULBING OF THE
LOW-LEVELS AHEAD OF THE EVENT. THERE IS PERHAPS A CHANCE OF A BRIEF
MIX-OVER TO RAIN/FREEZING RAIN ACROSS THE CAPE AND ISLANDS AS S-FLOW
AT THE SURFACE IS POSSIBLY ABLE TO NUDGE ABOVE-FREEZING TEMPERATURES
N. YET AS WE ARE IN A FROZEN TUNDRA...WITH ANY RAIN IT WOULD LIKELY
FREEZE ON SURFACES WHICH ARE QUITE COLD. THUS FREEZING RAIN PREVAILS
OVER RAIN IN THE FORECAST.

3) SNOWFALL...

FORECAST CONSENSUS OF A 0.3-0.6 N-S PRECIPITATION EVENT WITH A N-S
SNOW-TO-LIQUID RATIO GRADIENT RANGING FROM 15:1 TO 10:1 YIELDS HIGH-
END SNOW ADVISORY CRITERIA WITH SNOWFALL AMOUNTS RANGING ON AVERAGE
AROUND 3-6 INCHES. AREAS OF 6+ INCHES ARE EXPECTED...ESPECIALLY FROM
CENTRAL-CT E INTO SE-MA /INCLUDING THE UPPER-CAPE/. A CHALLENGE AND
A LOT OF UNCERTAINTY WITH RESPECT TO HEADLINES AND DECISION-MAKING.

EVALUATING LOW-LEVEL THERMAL PROFILES TOWARDS SNOW-TO-LIQUID RATIOS
DERIVED VIA A COBB-TECHNIQUE...WITH THE GREATEST LIFT OCCURRING
JUST BENEATH OR WITHIN THE DENDRITIC-GROWTH ZONE BASED ON A
CONSENSUS OF BUFKIT GFS PROFILES...ESPECIALLY IN HEAVIER- PRECIP
AREAS...BELIEVE THE SNOW WILL RANGE SOMEWHERE BETWEEN A WET AND
FLUFFY SNOW. SNOW PROPERTIES FROM FLUFFY TO WET LIKELY SIMILAR TO
THE N-S GRADIENT AS OUTLINED ABOVE.

4) HEADLINES...

HATE A WOBBLING FORECAST WHICH IS TYPICAL WITH SUCH SMALL EVENTS.
UNCERTAINTY DERIVES FROM LOW-LEVEL THERMAL PROFILES AND PRECIP
AMOUNTS. SURELY EXPECTING SNOW...BUT WITH ANY SHIFT N-S OF COLDER
AIR AND/OR PRECIPITATION AMOUNTS RESULTS IN AREAS SHIFTING FROM
ADVISORY TO WARNING...OR VICE VERSA. ENOUGH TO JUST PULL YOUR HAIR
OUT. THEN THERE IS THE TIMING OF THE SYSTEM THAT HAS SPED UP
SLIGHTLY. A SHORTER RESIDENCE TIME OF COURSE WOULD YIELD LESSER
SNOWFALL AMOUNTS. QUITE A CHALLENGING FORECAST RIGHT ON THE CUSP
OF HEADLINE THRESHOLDS.

THE EVENT DOES TAKE PLACE MAINLY FROM SUNDAY EVENING INTO THE EARLY
MORNING HOURS ON MONDAY DURING WHICH TIME THERE IS NOT MUCH TRAFFIC
ON THE ROAD. IS THIS A HIGH IMPACT EVENT THAT WARRANTS WARNINGS? A
QUESTION TO STRUGGLE WITH AS WARNINGS ARE NECESSARY WHEN WE ARE
CONFIDENT IN MEETING OR EXCEEDING 6+ INCH CRITERIA. YET THE QUESTION
IN FRONT OF US IS WHERE WILL THE HIGHER AMOUNTS OF SNOW FOCUS? HAVE
TO MAKE SOME SORT OF CALL...THE NEEDS OF THE MANY OUTWEIGH THE NEEDS
OF THE FEW.

ADVISORIES POSTED WHERE THERE IS HIGH CONFIDENCE OF SNOW BUT LIKELY
TO REMAIN BELOW THE 6-INCH THRESHOLD FOR WARNING. WATCHES CONTINUE
AND HAVE BEEN EXTENDED TO THE S-COAST TO COVER FOR THE UNCERTAINTY
OF THE AREA EITHER FALLING WITHIN OR IN EXCESS OF ADVISORY-LEVEL
SNOWS. AGAIN...6+ INCH AMOUNTS ARE ANTICIPATED BUT EXACTLY WHERE IS
UNCERTAIN.

5) CLOSING NOTES...

SOME CONCERN FOR THE EARLY MONDAY MORNING COMMUTE FOR E/SE MA AND
RI. WHILE MOST OF THE SNOW IS EXPECTED TO BE IMMEDIATELY OFFSHORE
WITH SUNRISE MONDAY...COMMUTERS COULD ENCOUNTER SLICK AND SLIPPERY
ROAD CONDITIONS. SNOW COULD POSSIBLY LINGER OVER SE MA SO THERE IS
THE POTENTIAL FOR REDUCED VISIBILITIES.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...

BIG PICTURE... THE BROAD UPPER FLOW SHOWS A RIDGE IN THE EAST AND
TROUGH IN THE WEST WITH A WEST SOUTHWEST FLOW FROM THE PLAINS TO THE
EASTERN USA COAST. WITHIN THIS FLOW ARE BOTH NORTHERN AND SOUTHERN
STREAMS AT THE START OF THE WEEK. THE WESTERN TROUGH MIGRATES EAST
DURING THE MIDWEEK AT WHICH TIME THE TWO STREAMS MERGE TO FORM A 140-
160 KT UPPER JET FEEDING NORTHEAST INTO THE GREAT LAKES AND ST
LAWRENCE VALLEY. THIS JET LINGERS OVER OR NEAR NEW ENGLAND THURSDAY-
FRIDAY BEFORE MOVING OFF. THE WESTERN TROUGH MOVES ACROSS NEW
ENGLAND BY THE END OF THE WEEK.

DAILIES...

MONDAY... SUNDAY STORM MOVES OFF PAST NOVA SCOTIA WHILE THE
SUPPORTING UPPER SHORTWAVE AND COLD POOL SWING ACROSS NEW ENGLAND.
THE COOLEST AIR ALOFT IS IN NORTHERN NEW ENGLAND WHILE LEFTOVER
MOISTURE LINGERS BELOW 800 MB THROUGH THE DAY. THE GFS IS FASTER
THAN THE ECMWF IN BRINGING RISING PRESSURE TO THE REGION BUT HAVE 1
MB/HOUR RISES HERE BY EVENING. PUT TOGETHER...EXPECT A CLEARING
TREND BUT WITH LEFTOVER CLOUDS ESPECIALLY NORTH OF THE MASS PIKE.
SUSTAINED NORTHWEST WINDS SHOULD RISE TO 15-20 KTS. MIXING REACHES
TO AT LEAST 850 MB AND POSSIBLY A LITTLE HIGHER...WHICH SUPPORTS
GUSTS TO AT LEAST 30 KNOTS AND POSSIBLY 35 KNOTS. TEMPS AT 850 MB
WILL BE -11C TO -14C...MIXING THIS TO THE SURFACE WOULD SUPPORT MAX
SFC TEMPS IN THE 30S. MIN TEMPERATURES UPSTREAM THIS MORNING WERE IN
THE SINGLE NUMBERS WITH A FEW SPOTS BELOW ZERO. WITH LIGHT PRESSURE
GRADIENT ESP IN THE WEST...WE TENDED A FEW DEGREES COOLER THAN
CONSENSUS.

TUESDAY-WEDNESDAY... HIGH PRESSURE IN CONTROL MUCH OF TUESDAY BUT
MOVING OFFSHORE DURING THE AFTERNOON. CROSS SECTIONS SHOW INCREASING
MOISTURE AT MID AND HIGH CLOUD LEVEL...SO INCREASING HIGH CLOUDS.
SYSTEM MOVING INTO THE GREAT LAKES SPREADS PCPN INTO NEW YORK...BUT
WARM ADVECTION LIFT REMAINS MOSTLY TO OUR WEST THROUGH THE
AFTERNOON. SOME LIFT FORECAST AT 290K /ABOUT 730 MB AT THE TIME/ BUT
NONE BELOW THAT. MEANWHILE DEWPOINTS IN THE SINGLE NUMBERS PROGRESS
INTO THE TEENS DURING THE DAY...BUT ENOUGH OF A TEMP/DEWPOINT SPREAD
TO SLOW THE ADVANCE OF ANY PCPN FROM THE CLOUDS BY A FEW HOURS.

WARM ADVECTION LIFT MUCH OF THE NIGHT SUPPORTS THE IDEA OF PCPN.
TEMPERATURES START COLD DURING THE EVENING BUT SHOULD RISE
OVERNIGHT. THE QUESTION REMAINS AS TO HOW HIGH THEY WILL CLIMB. EVEN
WITH THE SURFACE SYSTEM TRACKING UP THE ST LAWRENCE VALLEY THERE IS
COLD GROUND AND A COLD SNOWPACK. THIS WOULD ALLOW THE WARMER TEMPS
TO SCREAM OVERHEAD WHILE THE IMMEDIATE SURFACE REMAINS SEVERAL
DEGREES COLDER. WE TRIMMED TEMPS BACK A LITTLE FROM MODEL
VALUES...BUT LOW CONFIDENCE AT THIS TIME DUE TO THE POTENTIAL THAT
SURFACE TEMPS COULD REMAIN IN THE 30S.

QPF FORECASTS RANGE FROM 0.50 TO 1.00 INCHES WITH THE HIGHER AMOUNTS
TENDING TOWARD THE SOUTH COAST. THIS POINTS TO A MESSY STORM WITH
INITIAL SNOW ACCUMS OF SEVERAL INCHES FOLLOWED BY A CHANGE TO
MEASUREABLE ICE ACCUMULATION AND THEN A CHANGE TO RAIN WITH
POTENTIAL FOR POOR DRAINAGE FLOODING IN BETWEEN THE SNOW BANKS.

THE COLD FRONT SHOULD MOVE THROUGH DURING THE AFTERNOON/EVENING WITH
A SHIFT TO NORTHWEST WINDS. THIS WILL CHANGE THE PCPN BACK TO SNOW
BEFORE TAPERING OFF.

THURSDAY...DIFERENCES IN THE GFS AND ECMWF IN HANDING THE UPPER JET.
THE ECMWF MOVES THE JET OFFSHORE AND PUTS SOUTHERN NEW ENGLAND
INTO SUBSIDENCE. THE GFS MAINTAINS THE JET OVERHEAD WITH OUR AREA
IN THE RIGHT ENTRANCE REGION. THE FIRST SCENARIO ENDS THE PCPN AND
COOLS THE AIR. THE SECOND SCENARIO WOULD SUPPORT LIFT AND GENERATE
WAVES ALONG THE DEPARTING COLD FRONT...MAINTAINING A CHANCE OF
SNOW OVER AT LEAST SOUTHERN PARTS OF OUR AREA. OUR THURSDAY
FORECAST TENDS TOWARD THE LATTER FOR NOW.

FRIDAY-SATURDAY... HIGH PRESSURE BUILDS OVER THE REGION THURSDAY
NIGHT AND FRIDAY WITH CLEARING SKIES AND A BRIEF PERIOD OF COLD AIR.
TEMPS ALOFT TREND UP ABOUT 10C ON SATURDAY SUGGESTING LESS CHILL AT
THE SURFACE. ANOTHER COLD FRONT APPROACHES THE ST LAWRENCE VALLEY
AND COULD SPREAD SOME CLOUDS INTO OUR AREA SATURDAY
AFTERNOON/EVENING. BUT PCPN CHANCES LOOK SMALL.


&&

.AVIATION /21Z SATURDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /THROUGH MONDAY MORNING/...

21Z UPDATE...

TONIGHT THROUGH SUNDAY MIDDAY...HIGH CONFIDENCE.

VFR. LOWERING AND THICKENING CLOUDS SUNDAY MORNING INTO MIDDAY.
LOW-END VFR TO W-TERMINALS BY END OF PERIOD.

SUNDAY AFTERNOON INTO MONDAY MORNING...MODERATE CONFIDENCE.

SNOW OVERSPREADS THE REGION W-E. CIGS/VSBYS DETERIORATE TO MVFR-
IFR BY EARLY EVENING...WIDESPREAD IFR-LIFR SUNDAY NIGHT. SN TO MIX
WITH OR CHANGE TO FZRA ACROSS OFFSHORE ISLAND TERMINALS OVERNIGHT.
PRECIP ENDS W-E TOWARD DAYBREAK MONDAY....CONDITIONS IMPROVE.

KBOS TAF...MODERATE CONFIDENCE. TRENDS CERTAIN BUT NOT SO MUCH THE
ACTUAL TIMING OF IMPACTS.

KBDL TAF...MODERATE CONFIDENCE. TRENDS CERTAIN BUT NOT SO MUCH
THE ACTUAL TIMING OF IMPACTS.

OUTLOOK...MONDAY THROUGH THURSDAY...

MONDAY... HIGH CONFIDENCE. SOME IFR/MVFR IN SNOW EARLY MORNING BUT
OTHERWISE CONDITIONS WILL IMPROVE TO VFR DURING THE MORNING.
NORTHWEST WINDS WILL INCREASE WITH GUSTS AROUND 30 KNOTS BY MIDDAY.
VFR AND DIMINISHING WIND MONDAY NIGHT.

TUESDAY...MODERATE CONFIDENCE. VFR DURING THE DAY WITH INCREASING
SKY COVER. MVFR TUESDAY EVENING BECOMING IFR/LIFR OVERNIGHT IN
DEVELOPING SNOW AND FREEZING RAIN.

WEDNESDAY...MODERATE CONFIDENCE. IFR/LIFR IN RAIN AND FREEZING RAIN.

THURSDAY...LOW CONFIDENCE. VFR NORTH OF A HFD-BOS LINE. MVFR CIGS
AND AREAS OF MVFR/IFR VSBYS IN SNOW.


&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /THROUGH MONDAY MORNING/...HIGH CONFIDENCE.

HIGH PRESSURE NEARBY WILL KEEP WINDS/SEAS WELL BELOW SMALL CRAFT
ADVISORY THRESHOLDS INTO SUNDAY MORNING. A WEAK WAVE OF LOW
PRESSURE MOVES ACROSS THE WATERS LATE SUNDAY INTO SUNDAY NIGHT...
BUT WEAK PRESSURE GRADIENT SHOULD KEEP WINDS/SEAS BELOW SMALL
CRAFT THRESHOLDS.

OUTLOOK...MONDAY THROUGH THURSDAY..MODERATE CONFIDENCE.

MONDAY...WEST TO NORTHWEST WINDS INCREASE WITH FREQUENT GUSTS TO
GALE FORCE ESPECIALLY AWAY FROM THE NEARSHORE. THIS COULD GENERATE
SOME LIGHT FREEZING SPRAY ESPECIALLY EARLY MONDAY NIGHT. SEAS 5
TO 10 FEET. WINDS AND SEAS DIMINISH MONDAY NIGHT. A GALE WARNING
MAY BE NEEDED.

TUESDAY... LINGERING 5 FOOT SEAS ON THE OUTER WATERS BUT DIMINISHING
DURING THE MORNING.  WINDS AND SEAS INCREASE AGAIN TUESDAY NIGHT
AFTER MIDNIGHT AHEAD OF A GREAT LAKES COLD FRONT. SOUTH WINDS WILL
APPROACH 25 KNOTS WITH SEAS BUILDING TO 5 TO 8 FEET. VSBYS WILL
BE REDUCED IN SNOW CHANGING TO RAIN.

WEDNESDAY...SOUTHWEST WINDS WITH GUSTS 25-30 KNOTS.  SEAS BUILDING
TO 6 TO 12 FEET. REDUCED VSBYS IN RAIN. A SMALL CRAFT ADVISORY MAY
BE NEEDED.

THURSDAY...NORTHWEST WINDS WILL GUST TO 25 KNOTS...AND SEAS 5 TO 8
FEET. BOTH SHOULD DIMINISH TOWARD EVENING.  A SMALL CRAFT ADVISORY
MAY BE NEEDED.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY
     MORNING FOR CTZ002>004.
MA...WINTER WEATHER ADVISORY FROM NOON SUNDAY TO 7 AM EST MONDAY
     FOR MAZ002>008-010-014-023-024-026.
     WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY
     MORNING FOR MAZ009-011>013-015>022.
RI...WINTER WEATHER ADVISORY FROM NOON SUNDAY TO 7 AM EST MONDAY
     FOR RIZ008.
     WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY
     MORNING FOR RIZ001>007.
MARINE...NONE.

&&

$$
SYNOPSIS...WTB/SIPPRELL
NEAR TERM...SIPPRELL
SHORT TERM...SIPPRELL
LONG TERM...WTB
AVIATION...WTB/SIPPRELL
MARINE...WTB/SIPPRELL



000
FXUS61 KBOX 282100
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
400 PM EST SAT FEB 28 2015

.SYNOPSIS...
A FAST MOVING LOW PRESSURE SYSTEM WILL BRING ACCUMULATING SNOW TO
THE REGION LATE SUNDAY INTO SUNDAY NIGHT...WITH THE HIGHEST AMOUNTS
EXPECTED SOUTH OF THE MASSACHUSETTS TURNPIKE AND AWAY FROM THE
IMMEDIATE SOUTH COAST. HIGH PRESSURE BRINGS DRY COLD AIR FOR THE
EARLY WEEK. LOW PRESSURE FROM NORTHERN CANADA AND ASSOCIATED LOW
FORMING OVER THE PLAINS MONDAY WILL MERGE...THEN PASS WEST AND
NORTH OF NEW ENGLAND. THIS WILL SWING A COLD FRONT ACROSS THE
REGION ON WEDNESDAY. DRY AND COLD WEATHER RETURNS FOR THE END OF
THE WEEK.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
INTO THIS EVENING...

HIGH PRESSURE PUSHING E INTO THE REGION. TEMPERATURES EXPECTED TO
QUICKLY DROP WITH MOSTLY CLEAR CONDITIONS AND LIGHT WINDS.

TONIGHT...

COLD. CONDITIONS WILL BE JUST RIGHT TO ALLOW FOR GOOD RADIATIONAL
COOLING...ESPECIALLY TO THE E WHERE THE IMPACT OF INCREASING MID- TO
HIGH-CLOUDS LATE IN THE PERIOD WILL BE LESS. LOOKING AT SUB-ZERO
LOWS FOR LOW-LYING AREAS WHERE COLD-AIR DRAINAGE EFFECTS OFF THE
HIGH TERRAIN ARE MAXIMIZED. HIGH-TERRAIN SHOULD REMAIN AT OR ABOVE
ZERO.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
*/ SUNDAY MORNING INTO MIDDAY...

QUIET WEATHER. CLOUDS THICKENING AS WINDS INCREASE OUT OF THE S.
WILL SEE TEMPERATURES GRADUALLY MODERATE INTO THE MID- TO UPPER-20S.

*/ SUNDAY AFTERNOON INTO EARLY MONDAY MORNING...

1) HIGHLIGHTS...

 - SNOW SUNDAY AFTERNOON INTO MONDAY MORNING
 - GREATEST INTENSITY SUNDAY EVENING AND OVERNIGHT
 - 6+ INCH SNOWFALLS EXPECTED BUT EXACTLY WHERE REMAINS UNCERTAIN
 - ANNOYINGLY...FORECAST GUIDANCE CONTINUES TO WOBBLE

1) OVERVIEW...

BROAD ISENTROPIC OVER-RUNNING EVENT OF GULF MOISTURE ALONG THE 275-
295K SURFACES AMPLIFIED BY A N-STREAM IMPULSE DURING THE TIMEFRAME
POSSIBLY INVOKING AN AREA OF LOW PRESSURE THAT SKIRTS ALONG THE S-
COAST SUBSEQUENTLY ENHANCING LOW-LEVEL WIND PROFILE. LIGHT-MODERATE
SNOWFALL IS ANTICIPATED WITH LOCALLY HEAVIER AMOUNTS. THE INTENSE
PORTION OF SNOWFALL IS EXPECTED SUNDAY EVENING AND OVERNIGHT ENDING
EARLY MONDAY MORNING.

MODEL PREFERENCE GIVEN TO THE ECMWF/GFS/REGIONAL CANADIAN WHICH WILL
SERVE AS THE CONSENSUS OF GUIDANCE FOR THIS DISCUSSION. THE 28.12Z
NAM WAS CONSIDERED AN OUTLIER WITH ITS AGGRESSIVE-MODE AND SECONDARY
LOW DEVELOPMENT JUST OFFSHORE.

2) PRECIPITATION-TYPE...

EVALUATING THERMAL FIELDS...BLEND OF FORECAST CONSENSUS PUTS THE
-2C H925 ISOTHERM W-E ACROSS S-TIER OF CT/RI AND ACROSS SE MA WITH
THE 0C H85 ISOTHERM JUST S OF LONG-ISLAND AND NANTUCKET COASTLINES.
THE CONSENSUS OF 1000-850 MB CRITICAL THICKNESSES LAYS RIGHT ALONG
THE IMMEDIATE S-COAST OF LONG-ISLAND AND CAPE COD.

AN ALL SNOW-EVENT WHEN CONSIDERING DYNAMIC-COOLING/WETBULBING OF THE
LOW-LEVELS AHEAD OF THE EVENT. THERE IS PERHAPS A CHANCE OF A BRIEF
MIX-OVER TO RAIN/FREEZING RAIN ACROSS THE CAPE AND ISLANDS AS S-FLOW
AT THE SURFACE IS POSSIBLY ABLE TO NUDGE ABOVE-FREEZING TEMPERATURES
N. YET AS WE ARE IN A FROZEN TUNDRA...WITH ANY RAIN IT WOULD LIKELY
FREEZE ON SURFACES WHICH ARE QUITE COLD. THUS FREEZING RAIN PREVAILS
OVER RAIN IN THE FORECAST.

3) SNOWFALL...

FORECAST CONSENSUS OF A 0.3-0.6 N-S PRECIPITATION EVENT WITH A N-S
SNOW-TO-LIQUID RATIO GRADIENT RANGING FROM 15:1 TO 10:1 YIELDS HIGH-
END SNOW ADVISORY CRITERIA WITH SNOWFALL AMOUNTS RANGING ON AVERAGE
AROUND 3-6 INCHES. AREAS OF 6+ INCHES ARE EXPECTED...ESPECIALLY FROM
CENTRAL-CT E INTO SE-MA /INCLUDING THE UPPER-CAPE/. A CHALLENGE AND
A LOT OF UNCERTAINTY WITH RESPECT TO HEADLINES AND DECISION-MAKING.

EVALUATING LOW-LEVEL THERMAL PROFILES TOWARDS SNOW-TO-LIQUID RATIOS
DERIVED VIA A COBB-TECHNIQUE...WITH THE GREATEST LIFT OCCURRING
JUST BENEATH OR WITHIN THE DENDRITIC-GROWTH ZONE BASED ON A
CONSENSUS OF BUFKIT GFS PROFILES...ESPECIALLY IN HEAVIER- PRECIP
AREAS...BELIEVE THE SNOW WILL RANGE SOMEWHERE BETWEEN A WET AND
FLUFFY SNOW. SNOW PROPERTIES FROM FLUFFY TO WET LIKELY SIMILAR TO
THE N-S GRADIENT AS OUTLINED ABOVE.

4) HEADLINES...

HATE A WOBBLING FORECAST WHICH IS TYPICAL WITH SUCH SMALL EVENTS.
UNCERTAINTY DERIVES FROM LOW-LEVEL THERMAL PROFILES AND PRECIP
AMOUNTS. SURELY EXPECTING SNOW...BUT WITH ANY SHIFT N-S OF COLDER
AIR AND/OR PRECIPITATION AMOUNTS RESULTS IN AREAS SHIFTING FROM
ADVISORY TO WARNING...OR VICE VERSA. ENOUGH TO JUST PULL YOUR HAIR
OUT. THEN THERE IS THE TIMING OF THE SYSTEM THAT HAS SPED UP
SLIGHTLY. A SHORTER RESIDENCE TIME OF COURSE WOULD YIELD LESSER
SNOWFALL AMOUNTS. QUITE A CHALLENGING FORECAST RIGHT ON THE CUSP
OF HEADLINE THRESHOLDS.

THE EVENT DOES TAKE PLACE MAINLY FROM SUNDAY EVENING INTO THE EARLY
MORNING HOURS ON MONDAY DURING WHICH TIME THERE IS NOT MUCH TRAFFIC
ON THE ROAD. IS THIS A HIGH IMPACT EVENT THAT WARRANTS WARNINGS? A
QUESTION TO STRUGGLE WITH AS WARNINGS ARE NECESSARY WHEN WE ARE
CONFIDENT IN MEETING OR EXCEEDING 6+ INCH CRITERIA. YET THE QUESTION
IN FRONT OF US IS WHERE WILL THE HIGHER AMOUNTS OF SNOW FOCUS? HAVE
TO MAKE SOME SORT OF CALL...THE NEEDS OF THE MANY OUTWEIGH THE NEEDS
OF THE FEW.

ADVISORIES POSTED WHERE THERE IS HIGH CONFIDENCE OF SNOW BUT LIKELY
TO REMAIN BELOW THE 6-INCH THRESHOLD FOR WARNING. WATCHES CONTINUE
AND HAVE BEEN EXTENDED TO THE S-COAST TO COVER FOR THE UNCERTAINTY
OF THE AREA EITHER FALLING WITHIN OR IN EXCESS OF ADVISORY-LEVEL
SNOWS. AGAIN...6+ INCH AMOUNTS ARE ANTICIPATED BUT EXACTLY WHERE IS
UNCERTAIN.

5) CLOSING NOTES...

SOME CONCERN FOR THE EARLY MONDAY MORNING COMMUTE FOR E/SE MA AND
RI. WHILE MOST OF THE SNOW IS EXPECTED TO BE IMMEDIATELY OFFSHORE
WITH SUNRISE MONDAY...COMMUTERS COULD ENCOUNTER SLICK AND SLIPPERY
ROAD CONDITIONS. SNOW COULD POSSIBLY LINGER OVER SE MA SO THERE IS
THE POTENTIAL FOR REDUCED VISIBILITIES.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...

BIG PICTURE... THE BROAD UPPER FLOW SHOWS A RIDGE IN THE EAST AND
TROUGH IN THE WEST WITH A WEST SOUTHWEST FLOW FROM THE PLAINS TO THE
EASTERN USA COAST. WITHIN THIS FLOW ARE BOTH NORTHERN AND SOUTHERN
STREAMS AT THE START OF THE WEEK. THE WESTERN TROUGH MIGRATES EAST
DURING THE MIDWEEK AT WHICH TIME THE TWO STREAMS MERGE TO FORM A 140-
160 KT UPPER JET FEEDING NORTHEAST INTO THE GREAT LAKES AND ST
LAWRENCE VALLEY. THIS JET LINGERS OVER OR NEAR NEW ENGLAND THURSDAY-
FRIDAY BEFORE MOVING OFF. THE WESTERN TROUGH MOVES ACROSS NEW
ENGLAND BY THE END OF THE WEEK.

DAILIES...

MONDAY... SUNDAY STORM MOVES OFF PAST NOVA SCOTIA WHILE THE
SUPPORTING UPPER SHORTWAVE AND COLD POOL SWING ACROSS NEW ENGLAND.
THE COOLEST AIR ALOFT IS IN NORTHERN NEW ENGLAND WHILE LEFTOVER
MOISTURE LINGERS BELOW 800 MB THROUGH THE DAY. THE GFS IS FASTER
THAN THE ECMWF IN BRINGING RISING PRESSURE TO THE REGION BUT HAVE 1
MB/HOUR RISES HERE BY EVENING. PUT TOGETHER...EXPECT A CLEARING
TREND BUT WITH LEFTOVER CLOUDS ESPECIALLY NORTH OF THE MASS PIKE.
SUSTAINED NORTHWEST WINDS SHOULD RISE TO 15-20 KTS. MIXING REACHES
TO AT LEAST 850 MB AND POSSIBLY A LITTLE HIGHER...WHICH SUPPORTS
GUSTS TO AT LEAST 30 KNOTS AND POSSIBLY 35 KNOTS. TEMPS AT 850 MB
WILL BE -11C TO -14C...MIXING THIS TO THE SURFACE WOULD SUPPORT MAX
SFC TEMPS IN THE 30S. MIN TEMPERATURES UPSTREAM THIS MORNING WERE IN
THE SINGLE NUMBERS WITH A FEW SPOTS BELOW ZERO. WITH LIGHT PRESSURE
GRADIENT ESP IN THE WEST...WE TENDED A FEW DEGREES COOLER THAN
CONSENSUS.

TUESDAY-WEDNESDAY... HIGH PRESSURE IN CONTROL MUCH OF TUESDAY BUT
MOVING OFFSHORE DURING THE AFTERNOON. CROSS SECTIONS SHOW INCREASING
MOISTURE AT MID AND HIGH CLOUD LEVEL...SO INCREASING HIGH CLOUDS.
SYSTEM MOVING INTO THE GREAT LAKES SPREADS PCPN INTO NEW YORK...BUT
WARM ADVECTION LIFT REMAINS MOSTLY TO OUR WEST THROUGH THE
AFTERNOON. SOME LIFT FORECAST AT 290K /ABOUT 730 MB AT THE TIME/ BUT
NONE BELOW THAT. MEANWHILE DEWPOINTS IN THE SINGLE NUMBERS PROGRESS
INTO THE TEENS DURING THE DAY...BUT ENOUGH OF A TEMP/DEWPOINT SPREAD
TO SLOW THE ADVANCE OF ANY PCPN FROM THE CLOUDS BY A FEW HOURS.

WARM ADVECTION LIFT MUCH OF THE NIGHT SUPPORTS THE IDEA OF PCPN.
TEMPERATURES START COLD DURING THE EVENING BUT SHOULD RISE
OVERNIGHT. THE QUESTION REMAINS AS TO HOW HIGH THEY WILL CLIMB. EVEN
WITH THE SURFACE SYSTEM TRACKING UP THE ST LAWRENCE VALLEY THERE IS
COLD GROUND AND A COLD SNOWPACK. THIS WOULD ALLOW THE WARMER TEMPS
TO SCREAM OVERHEAD WHILE THE IMMEDIATE SURFACE REMAINS SEVERAL
DEGREES COLDER. WE TRIMMED TEMPS BACK A LITTLE FROM MODEL
VALUES...BUT LOW CONFIDENCE AT THIS TIME DUE TO THE POTENTIAL THAT
SURFACE TEMPS COULD REMAIN IN THE 30S.

QPF FORECASTS RANGE FROM 0.50 TO 1.00 INCHES WITH THE HIGHER AMOUNTS
TENDING TOWARD THE SOUTH COAST. THIS POINTS TO A MESSY STORM WITH
INITIAL SNOW ACCUMS OF SEVERAL INCHES FOLLOWED BY A CHANGE TO
MEASUREABLE ICE ACCUMULATION AND THEN A CHANGE TO RAIN WITH
POTENTIAL FOR POOR DRAINAGE FLOODING IN BETWEEN THE SNOW BANKS.

THE COLD FRONT SHOULD MOVE THROUGH DURING THE AFTERNOON/EVENING WITH
A SHIFT TO NORTHWEST WINDS. THIS WILL CHANGE THE PCPN BACK TO SNOW
BEFORE TAPERING OFF.

THURSDAY...DIFERENCES IN THE GFS AND ECMWF IN HANDING THE UPPER JET.
THE ECMWF MOVES THE JET OFFSHORE AND PUTS SOUTHERN NEW ENGLAND
INTO SUBSIDENCE. THE GFS MAINTAINS THE JET OVERHEAD WITH OUR AREA
IN THE RIGHT ENTRANCE REGION. THE FIRST SCENARIO ENDS THE PCPN AND
COOLS THE AIR. THE SECOND SCENARIO WOULD SUPPORT LIFT AND GENERATE
WAVES ALONG THE DEPARTING COLD FRONT...MAINTAINING A CHANCE OF
SNOW OVER AT LEAST SOUTHERN PARTS OF OUR AREA. OUR THURSDAY
FORECAST TENDS TOWARD THE LATTER FOR NOW.

FRIDAY-SATURDAY... HIGH PRESSURE BUILDS OVER THE REGION THURSDAY
NIGHT AND FRIDAY WITH CLEARING SKIES AND A BRIEF PERIOD OF COLD AIR.
TEMPS ALOFT TREND UP ABOUT 10C ON SATURDAY SUGGESTING LESS CHILL AT
THE SURFACE. ANOTHER COLD FRONT APPROACHES THE ST LAWRENCE VALLEY
AND COULD SPREAD SOME CLOUDS INTO OUR AREA SATURDAY
AFTERNOON/EVENING. BUT PCPN CHANCES LOOK SMALL.


&&

.AVIATION /21Z SATURDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /THROUGH MONDAY MORNING/...

21Z UPDATE...

TONIGHT THROUGH SUNDAY MIDDAY...HIGH CONFIDENCE.

VFR. LOWERING AND THICKENING CLOUDS SUNDAY MORNING INTO MIDDAY.
LOW-END VFR TO W-TERMINALS BY END OF PERIOD.

SUNDAY AFTERNOON INTO MONDAY MORNING...MODERATE CONFIDENCE.

SNOW OVERSPREADS THE REGION W-E. CIGS/VSBYS DETERIORATE TO MVFR-
IFR BY EARLY EVENING...WIDESPREAD IFR-LIFR SUNDAY NIGHT. SN TO MIX
WITH OR CHANGE TO FZRA ACROSS OFFSHORE ISLAND TERMINALS OVERNIGHT.
PRECIP ENDS W-E TOWARD DAYBREAK MONDAY....CONDITIONS IMPROVE.

KBOS TAF...MODERATE CONFIDENCE. TRENDS CERTAIN BUT NOT SO MUCH THE
ACTUAL TIMING OF IMPACTS.

KBDL TAF...MODERATE CONFIDENCE. TRENDS CERTAIN BUT NOT SO MUCH
THE ACTUAL TIMING OF IMPACTS.

OUTLOOK...MONDAY THROUGH THURSDAY...

MONDAY... HIGH CONFIDENCE. SOME IFR/MVFR IN SNOW EARLY MORNING BUT
OTHERWISE CONDITIONS WILL IMPROVE TO VFR DURING THE MORNING.
NORTHWEST WINDS WILL INCREASE WITH GUSTS AROUND 30 KNOTS BY MIDDAY.
VFR AND DIMINISHING WIND MONDAY NIGHT.

TUESDAY...MODERATE CONFIDENCE. VFR DURING THE DAY WITH INCREASING
SKY COVER. MVFR TUESDAY EVENING BECOMING IFR/LIFR OVERNIGHT IN
DEVELOPING SNOW AND FREEZING RAIN.

WEDNESDAY...MODERATE CONFIDENCE. IFR/LIFR IN RAIN AND FREEZING RAIN.

THURSDAY...LOW CONFIDENCE. VFR NORTH OF A HFD-BOS LINE. MVFR CIGS
AND AREAS OF MVFR/IFR VSBYS IN SNOW.


&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /THROUGH MONDAY MORNING/...HIGH CONFIDENCE.

HIGH PRESSURE NEARBY WILL KEEP WINDS/SEAS WELL BELOW SMALL CRAFT
ADVISORY THRESHOLDS INTO SUNDAY MORNING. A WEAK WAVE OF LOW
PRESSURE MOVES ACROSS THE WATERS LATE SUNDAY INTO SUNDAY NIGHT...
BUT WEAK PRESSURE GRADIENT SHOULD KEEP WINDS/SEAS BELOW SMALL
CRAFT THRESHOLDS.

OUTLOOK...MONDAY THROUGH THURSDAY..MODERATE CONFIDENCE.

MONDAY...WEST TO NORTHWEST WINDS INCREASE WITH FREQUENT GUSTS TO
GALE FORCE ESPECIALLY AWAY FROM THE NEARSHORE. THIS COULD GENERATE
SOME LIGHT FREEZING SPRAY ESPECIALLY EARLY MONDAY NIGHT. SEAS 5
TO 10 FEET. WINDS AND SEAS DIMINISH MONDAY NIGHT. A GALE WARNING
MAY BE NEEDED.

TUESDAY... LINGERING 5 FOOT SEAS ON THE OUTER WATERS BUT DIMINISHING
DURING THE MORNING.  WINDS AND SEAS INCREASE AGAIN TUESDAY NIGHT
AFTER MIDNIGHT AHEAD OF A GREAT LAKES COLD FRONT. SOUTH WINDS WILL
APPROACH 25 KNOTS WITH SEAS BUILDING TO 5 TO 8 FEET. VSBYS WILL
BE REDUCED IN SNOW CHANGING TO RAIN.

WEDNESDAY...SOUTHWEST WINDS WITH GUSTS 25-30 KNOTS.  SEAS BUILDING
TO 6 TO 12 FEET. REDUCED VSBYS IN RAIN. A SMALL CRAFT ADVISORY MAY
BE NEEDED.

THURSDAY...NORTHWEST WINDS WILL GUST TO 25 KNOTS...AND SEAS 5 TO 8
FEET. BOTH SHOULD DIMINISH TOWARD EVENING.  A SMALL CRAFT ADVISORY
MAY BE NEEDED.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY
     MORNING FOR CTZ002>004.
MA...WINTER WEATHER ADVISORY FROM NOON SUNDAY TO 7 AM EST MONDAY
     FOR MAZ002>008-010-014-023-024-026.
     WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY
     MORNING FOR MAZ009-011>013-015>022.
RI...WINTER WEATHER ADVISORY FROM NOON SUNDAY TO 7 AM EST MONDAY
     FOR RIZ008.
     WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY
     MORNING FOR RIZ001>007.
MARINE...NONE.

&&

$$
SYNOPSIS...WTB/SIPPRELL
NEAR TERM...SIPPRELL
SHORT TERM...SIPPRELL
LONG TERM...WTB
AVIATION...WTB/SIPPRELL
MARINE...WTB/SIPPRELL



000
FXUS61 KBOX 282100
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
400 PM EST SAT FEB 28 2015

.SYNOPSIS...
A FAST MOVING LOW PRESSURE SYSTEM WILL BRING ACCUMULATING SNOW TO
THE REGION LATE SUNDAY INTO SUNDAY NIGHT...WITH THE HIGHEST AMOUNTS
EXPECTED SOUTH OF THE MASSACHUSETTS TURNPIKE AND AWAY FROM THE
IMMEDIATE SOUTH COAST. HIGH PRESSURE BRINGS DRY COLD AIR FOR THE
EARLY WEEK. LOW PRESSURE FROM NORTHERN CANADA AND ASSOCIATED LOW
FORMING OVER THE PLAINS MONDAY WILL MERGE...THEN PASS WEST AND
NORTH OF NEW ENGLAND. THIS WILL SWING A COLD FRONT ACROSS THE
REGION ON WEDNESDAY. DRY AND COLD WEATHER RETURNS FOR THE END OF
THE WEEK.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
INTO THIS EVENING...

HIGH PRESSURE PUSHING E INTO THE REGION. TEMPERATURES EXPECTED TO
QUICKLY DROP WITH MOSTLY CLEAR CONDITIONS AND LIGHT WINDS.

TONIGHT...

COLD. CONDITIONS WILL BE JUST RIGHT TO ALLOW FOR GOOD RADIATIONAL
COOLING...ESPECIALLY TO THE E WHERE THE IMPACT OF INCREASING MID- TO
HIGH-CLOUDS LATE IN THE PERIOD WILL BE LESS. LOOKING AT SUB-ZERO
LOWS FOR LOW-LYING AREAS WHERE COLD-AIR DRAINAGE EFFECTS OFF THE
HIGH TERRAIN ARE MAXIMIZED. HIGH-TERRAIN SHOULD REMAIN AT OR ABOVE
ZERO.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
*/ SUNDAY MORNING INTO MIDDAY...

QUIET WEATHER. CLOUDS THICKENING AS WINDS INCREASE OUT OF THE S.
WILL SEE TEMPERATURES GRADUALLY MODERATE INTO THE MID- TO UPPER-20S.

*/ SUNDAY AFTERNOON INTO EARLY MONDAY MORNING...

1) HIGHLIGHTS...

 - SNOW SUNDAY AFTERNOON INTO MONDAY MORNING
 - GREATEST INTENSITY SUNDAY EVENING AND OVERNIGHT
 - 6+ INCH SNOWFALLS EXPECTED BUT EXACTLY WHERE REMAINS UNCERTAIN
 - ANNOYINGLY...FORECAST GUIDANCE CONTINUES TO WOBBLE

1) OVERVIEW...

BROAD ISENTROPIC OVER-RUNNING EVENT OF GULF MOISTURE ALONG THE 275-
295K SURFACES AMPLIFIED BY A N-STREAM IMPULSE DURING THE TIMEFRAME
POSSIBLY INVOKING AN AREA OF LOW PRESSURE THAT SKIRTS ALONG THE S-
COAST SUBSEQUENTLY ENHANCING LOW-LEVEL WIND PROFILE. LIGHT-MODERATE
SNOWFALL IS ANTICIPATED WITH LOCALLY HEAVIER AMOUNTS. THE INTENSE
PORTION OF SNOWFALL IS EXPECTED SUNDAY EVENING AND OVERNIGHT ENDING
EARLY MONDAY MORNING.

MODEL PREFERENCE GIVEN TO THE ECMWF/GFS/REGIONAL CANADIAN WHICH WILL
SERVE AS THE CONSENSUS OF GUIDANCE FOR THIS DISCUSSION. THE 28.12Z
NAM WAS CONSIDERED AN OUTLIER WITH ITS AGGRESSIVE-MODE AND SECONDARY
LOW DEVELOPMENT JUST OFFSHORE.

2) PRECIPITATION-TYPE...

EVALUATING THERMAL FIELDS...BLEND OF FORECAST CONSENSUS PUTS THE
-2C H925 ISOTHERM W-E ACROSS S-TIER OF CT/RI AND ACROSS SE MA WITH
THE 0C H85 ISOTHERM JUST S OF LONG-ISLAND AND NANTUCKET COASTLINES.
THE CONSENSUS OF 1000-850 MB CRITICAL THICKNESSES LAYS RIGHT ALONG
THE IMMEDIATE S-COAST OF LONG-ISLAND AND CAPE COD.

AN ALL SNOW-EVENT WHEN CONSIDERING DYNAMIC-COOLING/WETBULBING OF THE
LOW-LEVELS AHEAD OF THE EVENT. THERE IS PERHAPS A CHANCE OF A BRIEF
MIX-OVER TO RAIN/FREEZING RAIN ACROSS THE CAPE AND ISLANDS AS S-FLOW
AT THE SURFACE IS POSSIBLY ABLE TO NUDGE ABOVE-FREEZING TEMPERATURES
N. YET AS WE ARE IN A FROZEN TUNDRA...WITH ANY RAIN IT WOULD LIKELY
FREEZE ON SURFACES WHICH ARE QUITE COLD. THUS FREEZING RAIN PREVAILS
OVER RAIN IN THE FORECAST.

3) SNOWFALL...

FORECAST CONSENSUS OF A 0.3-0.6 N-S PRECIPITATION EVENT WITH A N-S
SNOW-TO-LIQUID RATIO GRADIENT RANGING FROM 15:1 TO 10:1 YIELDS HIGH-
END SNOW ADVISORY CRITERIA WITH SNOWFALL AMOUNTS RANGING ON AVERAGE
AROUND 3-6 INCHES. AREAS OF 6+ INCHES ARE EXPECTED...ESPECIALLY FROM
CENTRAL-CT E INTO SE-MA /INCLUDING THE UPPER-CAPE/. A CHALLENGE AND
A LOT OF UNCERTAINTY WITH RESPECT TO HEADLINES AND DECISION-MAKING.

EVALUATING LOW-LEVEL THERMAL PROFILES TOWARDS SNOW-TO-LIQUID RATIOS
DERIVED VIA A COBB-TECHNIQUE...WITH THE GREATEST LIFT OCCURRING
JUST BENEATH OR WITHIN THE DENDRITIC-GROWTH ZONE BASED ON A
CONSENSUS OF BUFKIT GFS PROFILES...ESPECIALLY IN HEAVIER- PRECIP
AREAS...BELIEVE THE SNOW WILL RANGE SOMEWHERE BETWEEN A WET AND
FLUFFY SNOW. SNOW PROPERTIES FROM FLUFFY TO WET LIKELY SIMILAR TO
THE N-S GRADIENT AS OUTLINED ABOVE.

4) HEADLINES...

HATE A WOBBLING FORECAST WHICH IS TYPICAL WITH SUCH SMALL EVENTS.
UNCERTAINTY DERIVES FROM LOW-LEVEL THERMAL PROFILES AND PRECIP
AMOUNTS. SURELY EXPECTING SNOW...BUT WITH ANY SHIFT N-S OF COLDER
AIR AND/OR PRECIPITATION AMOUNTS RESULTS IN AREAS SHIFTING FROM
ADVISORY TO WARNING...OR VICE VERSA. ENOUGH TO JUST PULL YOUR HAIR
OUT. THEN THERE IS THE TIMING OF THE SYSTEM THAT HAS SPED UP
SLIGHTLY. A SHORTER RESIDENCE TIME OF COURSE WOULD YIELD LESSER
SNOWFALL AMOUNTS. QUITE A CHALLENGING FORECAST RIGHT ON THE CUSP
OF HEADLINE THRESHOLDS.

THE EVENT DOES TAKE PLACE MAINLY FROM SUNDAY EVENING INTO THE EARLY
MORNING HOURS ON MONDAY DURING WHICH TIME THERE IS NOT MUCH TRAFFIC
ON THE ROAD. IS THIS A HIGH IMPACT EVENT THAT WARRANTS WARNINGS? A
QUESTION TO STRUGGLE WITH AS WARNINGS ARE NECESSARY WHEN WE ARE
CONFIDENT IN MEETING OR EXCEEDING 6+ INCH CRITERIA. YET THE QUESTION
IN FRONT OF US IS WHERE WILL THE HIGHER AMOUNTS OF SNOW FOCUS? HAVE
TO MAKE SOME SORT OF CALL...THE NEEDS OF THE MANY OUTWEIGH THE NEEDS
OF THE FEW.

ADVISORIES POSTED WHERE THERE IS HIGH CONFIDENCE OF SNOW BUT LIKELY
TO REMAIN BELOW THE 6-INCH THRESHOLD FOR WARNING. WATCHES CONTINUE
AND HAVE BEEN EXTENDED TO THE S-COAST TO COVER FOR THE UNCERTAINTY
OF THE AREA EITHER FALLING WITHIN OR IN EXCESS OF ADVISORY-LEVEL
SNOWS. AGAIN...6+ INCH AMOUNTS ARE ANTICIPATED BUT EXACTLY WHERE IS
UNCERTAIN.

5) CLOSING NOTES...

SOME CONCERN FOR THE EARLY MONDAY MORNING COMMUTE FOR E/SE MA AND
RI. WHILE MOST OF THE SNOW IS EXPECTED TO BE IMMEDIATELY OFFSHORE
WITH SUNRISE MONDAY...COMMUTERS COULD ENCOUNTER SLICK AND SLIPPERY
ROAD CONDITIONS. SNOW COULD POSSIBLY LINGER OVER SE MA SO THERE IS
THE POTENTIAL FOR REDUCED VISIBILITIES.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...

BIG PICTURE... THE BROAD UPPER FLOW SHOWS A RIDGE IN THE EAST AND
TROUGH IN THE WEST WITH A WEST SOUTHWEST FLOW FROM THE PLAINS TO THE
EASTERN USA COAST. WITHIN THIS FLOW ARE BOTH NORTHERN AND SOUTHERN
STREAMS AT THE START OF THE WEEK. THE WESTERN TROUGH MIGRATES EAST
DURING THE MIDWEEK AT WHICH TIME THE TWO STREAMS MERGE TO FORM A 140-
160 KT UPPER JET FEEDING NORTHEAST INTO THE GREAT LAKES AND ST
LAWRENCE VALLEY. THIS JET LINGERS OVER OR NEAR NEW ENGLAND THURSDAY-
FRIDAY BEFORE MOVING OFF. THE WESTERN TROUGH MOVES ACROSS NEW
ENGLAND BY THE END OF THE WEEK.

DAILIES...

MONDAY... SUNDAY STORM MOVES OFF PAST NOVA SCOTIA WHILE THE
SUPPORTING UPPER SHORTWAVE AND COLD POOL SWING ACROSS NEW ENGLAND.
THE COOLEST AIR ALOFT IS IN NORTHERN NEW ENGLAND WHILE LEFTOVER
MOISTURE LINGERS BELOW 800 MB THROUGH THE DAY. THE GFS IS FASTER
THAN THE ECMWF IN BRINGING RISING PRESSURE TO THE REGION BUT HAVE 1
MB/HOUR RISES HERE BY EVENING. PUT TOGETHER...EXPECT A CLEARING
TREND BUT WITH LEFTOVER CLOUDS ESPECIALLY NORTH OF THE MASS PIKE.
SUSTAINED NORTHWEST WINDS SHOULD RISE TO 15-20 KTS. MIXING REACHES
TO AT LEAST 850 MB AND POSSIBLY A LITTLE HIGHER...WHICH SUPPORTS
GUSTS TO AT LEAST 30 KNOTS AND POSSIBLY 35 KNOTS. TEMPS AT 850 MB
WILL BE -11C TO -14C...MIXING THIS TO THE SURFACE WOULD SUPPORT MAX
SFC TEMPS IN THE 30S. MIN TEMPERATURES UPSTREAM THIS MORNING WERE IN
THE SINGLE NUMBERS WITH A FEW SPOTS BELOW ZERO. WITH LIGHT PRESSURE
GRADIENT ESP IN THE WEST...WE TENDED A FEW DEGREES COOLER THAN
CONSENSUS.

TUESDAY-WEDNESDAY... HIGH PRESSURE IN CONTROL MUCH OF TUESDAY BUT
MOVING OFFSHORE DURING THE AFTERNOON. CROSS SECTIONS SHOW INCREASING
MOISTURE AT MID AND HIGH CLOUD LEVEL...SO INCREASING HIGH CLOUDS.
SYSTEM MOVING INTO THE GREAT LAKES SPREADS PCPN INTO NEW YORK...BUT
WARM ADVECTION LIFT REMAINS MOSTLY TO OUR WEST THROUGH THE
AFTERNOON. SOME LIFT FORECAST AT 290K /ABOUT 730 MB AT THE TIME/ BUT
NONE BELOW THAT. MEANWHILE DEWPOINTS IN THE SINGLE NUMBERS PROGRESS
INTO THE TEENS DURING THE DAY...BUT ENOUGH OF A TEMP/DEWPOINT SPREAD
TO SLOW THE ADVANCE OF ANY PCPN FROM THE CLOUDS BY A FEW HOURS.

WARM ADVECTION LIFT MUCH OF THE NIGHT SUPPORTS THE IDEA OF PCPN.
TEMPERATURES START COLD DURING THE EVENING BUT SHOULD RISE
OVERNIGHT. THE QUESTION REMAINS AS TO HOW HIGH THEY WILL CLIMB. EVEN
WITH THE SURFACE SYSTEM TRACKING UP THE ST LAWRENCE VALLEY THERE IS
COLD GROUND AND A COLD SNOWPACK. THIS WOULD ALLOW THE WARMER TEMPS
TO SCREAM OVERHEAD WHILE THE IMMEDIATE SURFACE REMAINS SEVERAL
DEGREES COLDER. WE TRIMMED TEMPS BACK A LITTLE FROM MODEL
VALUES...BUT LOW CONFIDENCE AT THIS TIME DUE TO THE POTENTIAL THAT
SURFACE TEMPS COULD REMAIN IN THE 30S.

QPF FORECASTS RANGE FROM 0.50 TO 1.00 INCHES WITH THE HIGHER AMOUNTS
TENDING TOWARD THE SOUTH COAST. THIS POINTS TO A MESSY STORM WITH
INITIAL SNOW ACCUMS OF SEVERAL INCHES FOLLOWED BY A CHANGE TO
MEASUREABLE ICE ACCUMULATION AND THEN A CHANGE TO RAIN WITH
POTENTIAL FOR POOR DRAINAGE FLOODING IN BETWEEN THE SNOW BANKS.

THE COLD FRONT SHOULD MOVE THROUGH DURING THE AFTERNOON/EVENING WITH
A SHIFT TO NORTHWEST WINDS. THIS WILL CHANGE THE PCPN BACK TO SNOW
BEFORE TAPERING OFF.

THURSDAY...DIFERENCES IN THE GFS AND ECMWF IN HANDING THE UPPER JET.
THE ECMWF MOVES THE JET OFFSHORE AND PUTS SOUTHERN NEW ENGLAND
INTO SUBSIDENCE. THE GFS MAINTAINS THE JET OVERHEAD WITH OUR AREA
IN THE RIGHT ENTRANCE REGION. THE FIRST SCENARIO ENDS THE PCPN AND
COOLS THE AIR. THE SECOND SCENARIO WOULD SUPPORT LIFT AND GENERATE
WAVES ALONG THE DEPARTING COLD FRONT...MAINTAINING A CHANCE OF
SNOW OVER AT LEAST SOUTHERN PARTS OF OUR AREA. OUR THURSDAY
FORECAST TENDS TOWARD THE LATTER FOR NOW.

FRIDAY-SATURDAY... HIGH PRESSURE BUILDS OVER THE REGION THURSDAY
NIGHT AND FRIDAY WITH CLEARING SKIES AND A BRIEF PERIOD OF COLD AIR.
TEMPS ALOFT TREND UP ABOUT 10C ON SATURDAY SUGGESTING LESS CHILL AT
THE SURFACE. ANOTHER COLD FRONT APPROACHES THE ST LAWRENCE VALLEY
AND COULD SPREAD SOME CLOUDS INTO OUR AREA SATURDAY
AFTERNOON/EVENING. BUT PCPN CHANCES LOOK SMALL.


&&

.AVIATION /21Z SATURDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /THROUGH MONDAY MORNING/...

21Z UPDATE...

TONIGHT THROUGH SUNDAY MIDDAY...HIGH CONFIDENCE.

VFR. LOWERING AND THICKENING CLOUDS SUNDAY MORNING INTO MIDDAY.
LOW-END VFR TO W-TERMINALS BY END OF PERIOD.

SUNDAY AFTERNOON INTO MONDAY MORNING...MODERATE CONFIDENCE.

SNOW OVERSPREADS THE REGION W-E. CIGS/VSBYS DETERIORATE TO MVFR-
IFR BY EARLY EVENING...WIDESPREAD IFR-LIFR SUNDAY NIGHT. SN TO MIX
WITH OR CHANGE TO FZRA ACROSS OFFSHORE ISLAND TERMINALS OVERNIGHT.
PRECIP ENDS W-E TOWARD DAYBREAK MONDAY....CONDITIONS IMPROVE.

KBOS TAF...MODERATE CONFIDENCE. TRENDS CERTAIN BUT NOT SO MUCH THE
ACTUAL TIMING OF IMPACTS.

KBDL TAF...MODERATE CONFIDENCE. TRENDS CERTAIN BUT NOT SO MUCH
THE ACTUAL TIMING OF IMPACTS.

OUTLOOK...MONDAY THROUGH THURSDAY...

MONDAY... HIGH CONFIDENCE. SOME IFR/MVFR IN SNOW EARLY MORNING BUT
OTHERWISE CONDITIONS WILL IMPROVE TO VFR DURING THE MORNING.
NORTHWEST WINDS WILL INCREASE WITH GUSTS AROUND 30 KNOTS BY MIDDAY.
VFR AND DIMINISHING WIND MONDAY NIGHT.

TUESDAY...MODERATE CONFIDENCE. VFR DURING THE DAY WITH INCREASING
SKY COVER. MVFR TUESDAY EVENING BECOMING IFR/LIFR OVERNIGHT IN
DEVELOPING SNOW AND FREEZING RAIN.

WEDNESDAY...MODERATE CONFIDENCE. IFR/LIFR IN RAIN AND FREEZING RAIN.

THURSDAY...LOW CONFIDENCE. VFR NORTH OF A HFD-BOS LINE. MVFR CIGS
AND AREAS OF MVFR/IFR VSBYS IN SNOW.


&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /THROUGH MONDAY MORNING/...HIGH CONFIDENCE.

HIGH PRESSURE NEARBY WILL KEEP WINDS/SEAS WELL BELOW SMALL CRAFT
ADVISORY THRESHOLDS INTO SUNDAY MORNING. A WEAK WAVE OF LOW
PRESSURE MOVES ACROSS THE WATERS LATE SUNDAY INTO SUNDAY NIGHT...
BUT WEAK PRESSURE GRADIENT SHOULD KEEP WINDS/SEAS BELOW SMALL
CRAFT THRESHOLDS.

OUTLOOK...MONDAY THROUGH THURSDAY..MODERATE CONFIDENCE.

MONDAY...WEST TO NORTHWEST WINDS INCREASE WITH FREQUENT GUSTS TO
GALE FORCE ESPECIALLY AWAY FROM THE NEARSHORE. THIS COULD GENERATE
SOME LIGHT FREEZING SPRAY ESPECIALLY EARLY MONDAY NIGHT. SEAS 5
TO 10 FEET. WINDS AND SEAS DIMINISH MONDAY NIGHT. A GALE WARNING
MAY BE NEEDED.

TUESDAY... LINGERING 5 FOOT SEAS ON THE OUTER WATERS BUT DIMINISHING
DURING THE MORNING.  WINDS AND SEAS INCREASE AGAIN TUESDAY NIGHT
AFTER MIDNIGHT AHEAD OF A GREAT LAKES COLD FRONT. SOUTH WINDS WILL
APPROACH 25 KNOTS WITH SEAS BUILDING TO 5 TO 8 FEET. VSBYS WILL
BE REDUCED IN SNOW CHANGING TO RAIN.

WEDNESDAY...SOUTHWEST WINDS WITH GUSTS 25-30 KNOTS.  SEAS BUILDING
TO 6 TO 12 FEET. REDUCED VSBYS IN RAIN. A SMALL CRAFT ADVISORY MAY
BE NEEDED.

THURSDAY...NORTHWEST WINDS WILL GUST TO 25 KNOTS...AND SEAS 5 TO 8
FEET. BOTH SHOULD DIMINISH TOWARD EVENING.  A SMALL CRAFT ADVISORY
MAY BE NEEDED.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY
     MORNING FOR CTZ002>004.
MA...WINTER WEATHER ADVISORY FROM NOON SUNDAY TO 7 AM EST MONDAY
     FOR MAZ002>008-010-014-023-024-026.
     WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY
     MORNING FOR MAZ009-011>013-015>022.
RI...WINTER WEATHER ADVISORY FROM NOON SUNDAY TO 7 AM EST MONDAY
     FOR RIZ008.
     WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY
     MORNING FOR RIZ001>007.
MARINE...NONE.

&&

$$
SYNOPSIS...WTB/SIPPRELL
NEAR TERM...SIPPRELL
SHORT TERM...SIPPRELL
LONG TERM...WTB
AVIATION...WTB/SIPPRELL
MARINE...WTB/SIPPRELL




000
FXUS61 KBOX 282032
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
332 PM EST SAT FEB 28 2015

.SYNOPSIS...

A FAST MOVING LOW PRESSURE SYSTEM WILL BRING ACCUMULATING SNOW TO
THE REGION LATE SUNDAY INTO SUNDAY NIGHT...WITH THE HIGHEST AMOUNTS
EXPECTED SOUTH OF THE MASSACHUSETTS TURNPIKE AND AWAY FROM THE
IMMEDIATE SOUTH COAST. ANOTHER STORM IS LIKELY TUESDAY NIGHT INTO
WEDNESDAY...WITH SNOW AND MIXED PRECIPITATION LIKELY CHANGING TO
RAIN. COLD AND DRY CONDITIONS RETURN FOR THE END OF NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...

INTO THIS EVENING...

HIGH PRESSURE PUSHING E INTO THE REGION. TEMPERATURES EXPECTED TO
QUICKLY DROP WITH MOSTLY CLEAR CONDITIONS AND LIGHT WINDS.

TONIGHT...

COLD. CONDITIONS WILL BE JUST RIGHT TO ALLOW FOR GOOD RADIATIONAL
COOLING...ESPECIALLY TO THE E WHERE THE IMPACT OF INCREASING MID- TO
HIGH-CLOUDS LATE IN THE PERIOD WILL BE LESS. LOOKING AT SUB-ZERO
LOWS FOR LOW-LYING AREAS WHERE COLD-AIR DRAINAGE EFFECTS OFF THE
HIGH TERRAIN ARE MAXIMIZED. HIGH-TERRAIN SHOULD REMAIN AT OR ABOVE
ZERO.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...

*/ SUNDAY MORNING INTO MIDDAY...

QUIET WEATHER. CLOUDS THICKENING AS WINDS INCREASE OUT OF THE S.
WILL SEE TEMPERATURES GRADUALLY MODERATE INTO THE MID- TO UPPER-20S.

*/ SUNDAY AFTERNOON INTO EARLY MONDAY MORNING...

1) HIGHLIGHTS...

 - SNOW SUNDAY AFTERNOON INTO MONDAY MORNING
 - GREATEST INTENSITY SUNDAY EVENING AND OVERNIGHT
 - 6+ INCH SNOWFALLS EXPECTED BUT EXACTLY WHERE REMAINS UNCERTAIN
 - ANNOYINGLY...FORECAST GUIDANCE CONTINUES TO WOBBLE

1) OVERVIEW...

BROAD ISENTROPIC OVER-RUNNING EVENT OF GULF MOISTURE ALONG THE 275-
295K SURFACES AMPLIFIED BY A N-STREAM IMPULSE DURING THE TIMEFRAME
POSSIBLY INVOKING AN AREA OF LOW PRESSURE THAT SKIRTS ALONG THE S-
COAST SUBSEQUENTLY ENHANCING LOW-LEVEL WIND PROFILE. LIGHT-MODERATE
SNOWFALL IS ANTICIPATED WITH LOCALLY HEAVIER AMOUNTS. THE INTENSE
PORTION OF SNOWFALL IS EXPECTED SUNDAY EVENING AND OVERNIGHT ENDING
EARLY MONDAY MORNING.

MODEL PREFERENCE GIVEN TO THE ECMWF/GFS/REGIONAL CANADIAN WHICH WILL
SERVE AS THE CONSENSUS OF GUIDANCE FOR THIS DISCUSSION. THE 28.12Z
NAM WAS CONSIDERED AN OUTLIER WITH ITS AGGRESSIVE-MODE AND SECONDARY
LOW DEVELOPMENT JUST OFFSHORE.

2) PRECIPITATION-TYPE...

EVALUATING THERMAL FIELDS...BLEND OF FORECAST CONSENSUS PUTS THE
-2C H925 ISOTHERM W-E ACROSS S-TIER OF CT/RI AND ACROSS SE MA WITH
THE 0C H85 ISOTHERM JUST S OF LONG-ISLAND AND NANTUCKET COASTLINES.
THE CONSENSUS OF 1000-850 MB CRITICAL THICKNESSES LAYS RIGHT ALONG
THE IMMEDIATE S-COAST OF LONG-ISLAND AND CAPE COD.

AN ALL SNOW-EVENT WHEN CONSIDERING DYNAMIC-COOLING/WETBULBING OF THE
LOW-LEVELS AHEAD OF THE EVENT. THERE IS PERHAPS A CHANCE OF A BRIEF
MIX-OVER TO RAIN/FREEZING RAIN ACROSS THE CAPE AND ISLANDS AS S-FLOW
AT THE SURFACE IS POSSIBLY ABLE TO NUDGE ABOVE-FREEZING TEMPERATURES
N. YET AS WE ARE IN A FROZEN TUNDRA...WITH ANY RAIN IT WOULD LIKELY
FREEZE ON SURFACES WHICH ARE QUITE COLD. THUS FREEZING RAIN PREVAILS
OVER RAIN IN THE FORECAST.

3) SNOWFALL...

FORECAST CONSENSUS OF A 0.3-0.6 N-S PRECIPITATION EVENT WITH A N-S
SNOW-TO-LIQUID RATIO GRADIENT RANGING FROM 15:1 TO 10:1 YIELDS HIGH-
END SNOW ADVISORY CRITERIA WITH SNOWFALL AMOUNTS RANGING ON AVERAGE
AROUND 3-6 INCHES. AREAS OF 6+ INCHES ARE EXPECTED...ESPECIALLY FROM
CENTRAL-CT E INTO SE-MA /INCLUDING THE UPPER-CAPE/. A CHALLENGE AND
A LOT OF UNCERTAINTY WITH RESPECT TO HEADLINES AND DECISION-MAKING.

EVALUATING LOW-LEVEL THERMAL PROFILES TOWARDS SNOW-TO-LIQUID RATIOS
DERIVED VIA A COBB-TECHNIQUE...WITH THE GREATEST LIFT OCCURRING
JUST BENEATH OR WITHIN THE DENDRITIC-GROWTH ZONE BASED ON A
CONSENSUS OF BUFKIT GFS PROFILES...ESPECIALLY IN HEAVIER- PRECIP
AREAS...BELIEVE THE SNOW WILL RANGE SOMEWHERE BETWEEN A WET AND
FLUFFY SNOW. SNOW PROPERTIES FROM FLUFFY TO WET LIKELY SIMILAR TO
THE N-S GRADIENT AS OUTLINED ABOVE.

4) HEADLINES...

HATE A WOBBLING FORECAST WHICH IS TYPICAL WITH SUCH SMALL EVENTS.
UNCERTAINTY DERIVES FROM LOW-LEVEL THERMAL PROFILES AND PRECIP
AMOUNTS. SURELY EXPECTING SNOW...BUT WITH ANY SHIFT N-S OF COLDER
AIR AND/OR PRECIPITATION AMOUNTS RESULTS IN AREAS SHIFTING FROM
ADVISORY TO WARNING...OR VICE VERSA. ENOUGH TO JUST PULL YOUR HAIR
OUT. THEN THERE IS THE TIMING OF THE SYSTEM THAT HAS SPED UP
SLIGHTLY. A SHORTER RESIDENCE TIME OF COURSE WOULD YIELD LESSER
SNOWFALL AMOUNTS. QUITE A CHALLENGING FORECAST RIGHT ON THE CUSP
OF HEADLINE THRESHOLDS.

THE EVENT DOES TAKE PLACE MAINLY FROM SUNDAY EVENING INTO THE EARLY
MORNING HOURS ON MONDAY DURING WHICH TIME THERE IS NOT MUCH TRAFFIC
ON THE ROAD. IS THIS A HIGH IMPACT EVENT THAT WARRANTS WARNINGS? A
QUESTION TO STRUGGLE WITH AS WARNINGS ARE NECESSARY WHEN WE ARE
CONFIDENT IN MEETING OR EXCEEDING 6+ INCH CRITERIA. YET THE QUESTION
IN FRONT OF US IS WHERE WILL THE HIGHER AMOUNTS OF SNOW FOCUS? HAVE
TO MAKE SOME SORT OF CALL...THE NEEDS OF THE MANY OUTWEIGH THE NEEDS
OF THE FEW.

ADVISORIES POSTED WHERE THERE IS HIGH CONFIDENCE OF SNOW BUT LIKELY
TO REMAIN BELOW THE 6-INCH THRESHOLD FOR WARNING. WATCHES CONTINUE
AND HAVE BEEN EXTENDED TO THE S-COAST TO COVER FOR THE UNCERTAINTY
OF THE AREA EITHER FALLING WITHIN OR IN EXCESS OF ADVISORY-LEVEL
SNOWS. AGAIN...6+ INCH AMOUNTS ARE ANTICIPATED BUT EXACTLY WHERE IS
UNCERTAIN.

5) CLOSING NOTES...

SOME CONCERN FOR THE EARLY MONDAY MORNING COMMUTE FOR E/SE MA AND
RI. WHILE MOST OF THE SNOW IS EXPECTED TO BE IMMEDIATELY OFFSHORE
WITH SUNRISE MONDAY...COMMUTERS COULD ENCOUNTER SLICK AND SLIPPERY
ROAD CONDITIONS. SNOW COULD POSSIBLY LINGER OVER SE MA SO THERE IS
THE POTENTIAL FOR REDUCED VISIBILITIES.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...

HIGHLIGHTS...

*  CONDITIONS IMPROVE MONDAY
*  ANOTHER STORM POSSIBLE TUE NIGHT INTO WED...WITH SNOW OR
   MIXED PRECIP LIKELY CHANGING TO RAIN
*  COLD AND DRY TOWARD THE END OF THE WEEK

OVERVIEW AND MODEL PREFERENCES...

ONE THING IS FOR CERTAIN...WITH LITTLE CHANGE IN THE NAO/AO AND
THE PNA EXPECTED TO REBOUND FROM NEGATIVE VALUES BACK TOWARD A
MORE NEUTRAL SOLUTION...THE COLD AIR AND LONGWAVE TROF LOOK TO
REMAIN THROUGH THE LONG TERM FORECAST. THE ONLY CAVEAT WILL BE IN
THE LOW LVLS ON WED...WHEN A ROBUST SW LLJ WILL ALLOW LOW-MID LVL
TEMPS TO WARM CLOSER TO ABOVE CLIMATOLOGICAL NORMALS. HOWEVER...
THE COLD AIR INITIALLY IN PLACE WILL LEAD TO P-TYPE ISSUES FOR THE
MID WEEK SYSTEM. ECMWF DETERMINISTIC REMAINS THE MOST ROBUST OF
THE OPERATIONAL MODELS...WITH HIGHER AMPLIFICATION IN THE FLOW
PATTERN THAN THE GFS AND UKMET. IT STARTS MUCH COLDER...BUT ENDS
MUCH WARMER. HOWEVER...DO NOTE THAT SOME OF THE GEFS AND ECENS
ENSEMBLES AGREE WITH THE ECMWF. THEREFORE...WILL BE USING THE
ENSEMBLE BLEND AS A BASELINE AS THIS TAKES INTO ACCOUNT BOTH THE
MORE PROGRESSIVE /AND ULTIMATELY LESS ROBUST WITH THE THERMAL
DIFFERENCES/ AND THE POTENTIAL FOR A MORE DYNAMIC SYSTEM. WILL USE
THIS BLEND THROUGH THE REMAINDER OF THE FORECAST AS WELL.

DETAILS...

MONDAY...

MORNING SNOWS COME TO AN END EARLY ACROSS E MA...AND FLURRIES
DISSIPATE THROUGH THE BERKSHIRES AND LITCHFIELD HILLS AS DRY NW
FLOW MOVES IN. BLUSTERY CONDITIONS EXPECTED...AND EVEN THROUGH
HIGHS WILL STILL BE MAKING IT INTO THE LOW-UPPER 30S...NW WINDS
WITH GUSTS 25-35 MPH AT TIMES WILL YIELD WIND CHILLS STRUGGLING
INTO THE LOW 20S.

MONDAY NIGHT INTO TUESDAY...

HIGH PRES WILL MOVE ACROSS THE REGION. DRY CONDITIONS DOMINATE
ALTHOUGH WITH TEMPS REMAINING BELOW NORMAL.

TUESDAY NIGHT INTO THURSDAY...

MODEL CONSENSUS IS NOW GENERALLY IN AGREEMENT THAT BOTH THE NRN
AND SRN STREAMS PHASE IN SOME FASHION ACROSS THE CENTRAL CONUS
WITH THE FORMATION OF LOW PRES WHICH IS EXPECTED TO SLIDE ACROSS
SRN CANADA. WARM FRONT WILL APPROACH...BUT GIVEN DEEP SNOWPACK THE
LOW LVL FRONT MAY ACTUAL STALL NEAR THE S COAST AS THE LOW MOVES
OVER AS THE UPPER WARM FRONT SLIDES INTO CENTRAL NEW ENGLAND. THIS
PRESENTS A GOOD OVERRUNNING SITUATION WITH STRONG 50-60 KT H92 LLJ
OUT OF THE SW. GIVEN THAT THIS SYSTEM IS ASSOCIATED WITH THE SRN
STREAM...IT ALSO CARRIES WITH IT A FAIR AMOUNT OF MOISTURE AS
PWATS LOOK TO REACH 2-3 STD DEVIATIONS ABOVE NORMAL

SO ALL IN ALL..PLENTY OF INGREDIENTS FOR HEAVY PRECIP ACROSS THE
AREA. THE QUESTION WILL BE TYPE...ALL GUIDANCE BEGIN COLD ENOUGH
FOR SNOW AT ONSET TUE NIGHT INTO EARLY WED. ECMWF WOULD SUGGEST
MUCH MORE AND BETTER LIFT IN THE SNOW GROWTH REGION...SO THERE IS
THAT TO CONSIDER. IN ANY CASE...WILL NEED TO AT LEAST WATCH FOR
POTENTIAL WARNING LEVEL SNOWFALL BEFORE THE WARM AIR BEGINS TO
BUILD IN FROM S TO N THROUGH THE DAY ON WED. EVEN THOUGH THE ECMWF
STARTS THE COLDEST...IT ENDS AS THE WARMEST SOLUTION...BRINGING
THE H92 +8C LINE ALL THE WAY INTO CENTRAL MA. SO WE DO EXPECT A
GRADUAL SHIFT TO A WINTRY MIX INCLUDING SLEET AND FREEZING RAIN
FOR A TIME GIVEN THE DEEP SNOWPACK ACROSS THE REGION. SOME AREAS
OF WRN MA...AND THE HILLS OF NRN CT MAY ACTUALLY STAY AS A MIX OF
SLEET FREEZING RAIN AND EVEN MAYBE SOME SNOW GIVEN THAT THE SFC
WARM FRONT MAY STALL. WILL HAVE TO WATCH FOR ICY CONDITIONS WITH
AS MUCH AS A QUARTER INCH OF ICE NOT OUT OF THE QUESTION WHERE IT
DOESN/T SWITCH TO RAIN WITH MELTING /BEST CHANCE OF RAIN/MELT IS
IN RI/CT AND PORTIONS OF MASS E OF I-495 AND S OF THE MASS PIKE/.
HEAVY RAIN A THREAT TOO GIVEN UPPER LVL INSTABILITY AND ROBUST
LLJ...SO WHERE MELTING AND HEAVY RAIN ARE OBSERVED...POOR DRAINAGE
FLOODING IS A POSSIBILITY WHERE SNOW CLOGS AREA DRAINS.

THIS HEAVY MIXED PRECIP EVENT COULD LINGER INTO THU...THE MORE
AMPLIFIED ECMWF AND SEVERAL ECENS/GEFS MEMBERS SUGGEST THAT THE
LEFTOVER COLD FRONT STALLS WITH YET ANOTHER WEAK WAVE OF LOW PRES
MOVING THROUGH THU. OTHER SOLUTIONS ARE MORE PROGRESSIVE AND HAVE
LESS QPF /SNOW POTENTIALLY/ ON THE BACK END. HOWEVER...BY THU
AFTERNOON/EVENING...CONDITIONS SHOULD BE IMPROVING /ALTHOUGH WITH
RAPID TEMPERATURE DROP/.

LATE NEXT WEEK...

EVEN THOUGH THERE IS UNCERTAINTY WITH HOW AMPLIFIED THE PATTERN
IS BY LATE WEEK. IT APPEARS A PERIOD OF DRY BUT COLD WX IS LIKELY
AS ARCTIC AIR ONCE AGAIN SHIFTS IN BEHIND THE EXITING MID WEEK
SYSTEM.

&&

.AVIATION /20Z SATURDAY THROUGH THURSDAY/...

FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /THROUGH MONDAY MORNING/...

21Z UPDATE...

TONIGHT THROUGH SUNDAY MIDDAY...HIGH CONFIDENCE.

VFR. LOWERING AND THICKENING CLOUDS SUNDAY MORNING INTO MIDDAY.
LOW-END VFR TO W-TERMINALS BY END OF PERIOD.

SUNDAY AFTERNOON INTO MONDAY MORNING...MODERATE CONFIDENCE.

SNOW OVERSPREADS THE REGION W-E. CIGS/VSBYS DETERIORATE TO MVFR-
IFR BY EARLY EVENING...WIDESPREAD IFR-LIFR SUNDAY NIGHT. SN TO MIX
WITH OR CHANGE TO FZRA ACROSS OFFSHORE ISLAND TERMINALS OVERNIGHT.
PRECIP ENDS W-E TOWARD DAYBREAK MONDAY....CONDITIONS IMPROVE.

KBOS TAF...MODERATE CONFIDENCE. TRENDS CERTAIN BUT NOT SO MUCH THE
ACTUAL TIMING OF IMPACTS.

KBDL TAF...MODERATE CONFIDENCE. TRENDS CERTAIN BUT NOT SO MUCH
THE ACTUAL TIMING OF IMPACTS.

OUTLOOK...MONDAY THROUGH WEDNESDAY...

MONDAY...HIGH CONFIDENCE.

CONDITIONS IMPROVE EARLY FROM IFR/MVFR IN SNOWS AND LOW CIGS...
WITH VFR EXPECTED EVERYWHERE BY AFTERNOON. NW WINDS IN THE
AFTERNOON WITH GUSTS 25-30 KT.

MON NIGHT INTO TUE...HIGH CONFIDENCE.

MAINLY VFR. GRADUALLY LOWERING CIGS ON TUE.

TUE NIGHT INTO WED...MODERATE CONFIDENCE.

MIXED WINTRY PRECIP LIKELY STARTS AS ALL SNOW...TRANSITIONS TO A
MIX OF SLEET AND FREEZING RAIN...THEN TO ALL RAIN DURING THE DAY
ON WED. SOME SNOW AND ICE ACCUMULATIONS ARE LIKELY WITH IFR OR
POTENTIALLY EVEN LIFR CONDITIONS AT TIMES.

&&

.MARINE...

FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /THROUGH MONDAY MORNING/...HIGH CONFIDENCE.

HIGH PRESSURE NEARBY WILL KEEP WINDS/SEAS WELL BELOW SMALL CRAFT
ADVISORY THRESHOLDS INTO SUNDAY MORNING. A WEAK WAVE OF LOW
PRESSURE MOVES ACROSS THE WATERS LATE SUNDAY INTO SUNDAY NIGHT...
BUT WEAK PRESSURE GRADIENT SHOULD KEEP WINDS/SEAS BELOW SMALL
CRAFT THRESHOLDS.

OUTLOOK...MONDAY THROUGH WEDNESDAY...

MONDAY INTO MONDAY NIGHT...HIGH CONFIDENCE.

SW WINDS SHIFT TO THE NW DURING THE DAYLIGHT HOURS AS A COLD
FRONT SWEEPS ACROSS THE WATERS. ONCE WINDS SHIFT NW IN THE
AFTERNOON EXPECT GALE FORCE GUSTS 35-40KT. COLDER AIR TUE NIGHT
COULD LEAD TO LIGHT FREEZING SPRAY.

TUESDAY...MODERATE CONFIDENCE.

WINDS GRADUALLY DIMINISH OUT OF THE W-NW BUT SEAS ARE LIKELY TO
REMAIN ELEVATED 5-8FT ON THE OCEAN WATERS. SMALL CRAFT ADVISORIES
WILL LIKELY BE NEEDED.

TUESDAY NIGHT INTO WEDNESDAY...MODERATE CONFIDENCE.

SNOW CHANGES TO RAIN TUE NIGHT WITH LOW VSBYS OVER THE WATERS.
WINDS OUT OF THE S MAINLY AROUND 25-30 KT AT MOST. SEAS BUILD
12-15 FT BY DAYTIME ON WED ON SE OCEAN WATERS. SMALL CRAFT
ADVISORIES WILL LIKELY BE NEEDED.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...

CT...WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY
     MORNING FOR CTZ002>004.
MA...WINTER WEATHER ADVISORY FROM NOON SUNDAY TO 7 AM EST MONDAY
     FOR MAZ002>008-010-014-023-024-026.
     WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY
     MORNING FOR MAZ009-011>013-015>022.
RI...WINTER WEATHER ADVISORY FROM NOON SUNDAY TO 7 AM EST MONDAY
     FOR RIZ008.
     WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY
     MORNING FOR RIZ001>007.
MARINE...NONE.

&&

$$

SYNOPSIS...DOODY/SIPPRELL
NEAR TERM...SIPPRELL
SHORT TERM...SIPPRELL
LONG TERM...DOODY
AVIATION...DOODY/SIPPRELL
MARINE...DOODY/SIPPRELL




000
FXUS61 KBOX 282032
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
332 PM EST SAT FEB 28 2015

.SYNOPSIS...

A FAST MOVING LOW PRESSURE SYSTEM WILL BRING ACCUMULATING SNOW TO
THE REGION LATE SUNDAY INTO SUNDAY NIGHT...WITH THE HIGHEST AMOUNTS
EXPECTED SOUTH OF THE MASSACHUSETTS TURNPIKE AND AWAY FROM THE
IMMEDIATE SOUTH COAST. ANOTHER STORM IS LIKELY TUESDAY NIGHT INTO
WEDNESDAY...WITH SNOW AND MIXED PRECIPITATION LIKELY CHANGING TO
RAIN. COLD AND DRY CONDITIONS RETURN FOR THE END OF NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...

INTO THIS EVENING...

HIGH PRESSURE PUSHING E INTO THE REGION. TEMPERATURES EXPECTED TO
QUICKLY DROP WITH MOSTLY CLEAR CONDITIONS AND LIGHT WINDS.

TONIGHT...

COLD. CONDITIONS WILL BE JUST RIGHT TO ALLOW FOR GOOD RADIATIONAL
COOLING...ESPECIALLY TO THE E WHERE THE IMPACT OF INCREASING MID- TO
HIGH-CLOUDS LATE IN THE PERIOD WILL BE LESS. LOOKING AT SUB-ZERO
LOWS FOR LOW-LYING AREAS WHERE COLD-AIR DRAINAGE EFFECTS OFF THE
HIGH TERRAIN ARE MAXIMIZED. HIGH-TERRAIN SHOULD REMAIN AT OR ABOVE
ZERO.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...

*/ SUNDAY MORNING INTO MIDDAY...

QUIET WEATHER. CLOUDS THICKENING AS WINDS INCREASE OUT OF THE S.
WILL SEE TEMPERATURES GRADUALLY MODERATE INTO THE MID- TO UPPER-20S.

*/ SUNDAY AFTERNOON INTO EARLY MONDAY MORNING...

1) HIGHLIGHTS...

 - SNOW SUNDAY AFTERNOON INTO MONDAY MORNING
 - GREATEST INTENSITY SUNDAY EVENING AND OVERNIGHT
 - 6+ INCH SNOWFALLS EXPECTED BUT EXACTLY WHERE REMAINS UNCERTAIN
 - ANNOYINGLY...FORECAST GUIDANCE CONTINUES TO WOBBLE

1) OVERVIEW...

BROAD ISENTROPIC OVER-RUNNING EVENT OF GULF MOISTURE ALONG THE 275-
295K SURFACES AMPLIFIED BY A N-STREAM IMPULSE DURING THE TIMEFRAME
POSSIBLY INVOKING AN AREA OF LOW PRESSURE THAT SKIRTS ALONG THE S-
COAST SUBSEQUENTLY ENHANCING LOW-LEVEL WIND PROFILE. LIGHT-MODERATE
SNOWFALL IS ANTICIPATED WITH LOCALLY HEAVIER AMOUNTS. THE INTENSE
PORTION OF SNOWFALL IS EXPECTED SUNDAY EVENING AND OVERNIGHT ENDING
EARLY MONDAY MORNING.

MODEL PREFERENCE GIVEN TO THE ECMWF/GFS/REGIONAL CANADIAN WHICH WILL
SERVE AS THE CONSENSUS OF GUIDANCE FOR THIS DISCUSSION. THE 28.12Z
NAM WAS CONSIDERED AN OUTLIER WITH ITS AGGRESSIVE-MODE AND SECONDARY
LOW DEVELOPMENT JUST OFFSHORE.

2) PRECIPITATION-TYPE...

EVALUATING THERMAL FIELDS...BLEND OF FORECAST CONSENSUS PUTS THE
-2C H925 ISOTHERM W-E ACROSS S-TIER OF CT/RI AND ACROSS SE MA WITH
THE 0C H85 ISOTHERM JUST S OF LONG-ISLAND AND NANTUCKET COASTLINES.
THE CONSENSUS OF 1000-850 MB CRITICAL THICKNESSES LAYS RIGHT ALONG
THE IMMEDIATE S-COAST OF LONG-ISLAND AND CAPE COD.

AN ALL SNOW-EVENT WHEN CONSIDERING DYNAMIC-COOLING/WETBULBING OF THE
LOW-LEVELS AHEAD OF THE EVENT. THERE IS PERHAPS A CHANCE OF A BRIEF
MIX-OVER TO RAIN/FREEZING RAIN ACROSS THE CAPE AND ISLANDS AS S-FLOW
AT THE SURFACE IS POSSIBLY ABLE TO NUDGE ABOVE-FREEZING TEMPERATURES
N. YET AS WE ARE IN A FROZEN TUNDRA...WITH ANY RAIN IT WOULD LIKELY
FREEZE ON SURFACES WHICH ARE QUITE COLD. THUS FREEZING RAIN PREVAILS
OVER RAIN IN THE FORECAST.

3) SNOWFALL...

FORECAST CONSENSUS OF A 0.3-0.6 N-S PRECIPITATION EVENT WITH A N-S
SNOW-TO-LIQUID RATIO GRADIENT RANGING FROM 15:1 TO 10:1 YIELDS HIGH-
END SNOW ADVISORY CRITERIA WITH SNOWFALL AMOUNTS RANGING ON AVERAGE
AROUND 3-6 INCHES. AREAS OF 6+ INCHES ARE EXPECTED...ESPECIALLY FROM
CENTRAL-CT E INTO SE-MA /INCLUDING THE UPPER-CAPE/. A CHALLENGE AND
A LOT OF UNCERTAINTY WITH RESPECT TO HEADLINES AND DECISION-MAKING.

EVALUATING LOW-LEVEL THERMAL PROFILES TOWARDS SNOW-TO-LIQUID RATIOS
DERIVED VIA A COBB-TECHNIQUE...WITH THE GREATEST LIFT OCCURRING
JUST BENEATH OR WITHIN THE DENDRITIC-GROWTH ZONE BASED ON A
CONSENSUS OF BUFKIT GFS PROFILES...ESPECIALLY IN HEAVIER- PRECIP
AREAS...BELIEVE THE SNOW WILL RANGE SOMEWHERE BETWEEN A WET AND
FLUFFY SNOW. SNOW PROPERTIES FROM FLUFFY TO WET LIKELY SIMILAR TO
THE N-S GRADIENT AS OUTLINED ABOVE.

4) HEADLINES...

HATE A WOBBLING FORECAST WHICH IS TYPICAL WITH SUCH SMALL EVENTS.
UNCERTAINTY DERIVES FROM LOW-LEVEL THERMAL PROFILES AND PRECIP
AMOUNTS. SURELY EXPECTING SNOW...BUT WITH ANY SHIFT N-S OF COLDER
AIR AND/OR PRECIPITATION AMOUNTS RESULTS IN AREAS SHIFTING FROM
ADVISORY TO WARNING...OR VICE VERSA. ENOUGH TO JUST PULL YOUR HAIR
OUT. THEN THERE IS THE TIMING OF THE SYSTEM THAT HAS SPED UP
SLIGHTLY. A SHORTER RESIDENCE TIME OF COURSE WOULD YIELD LESSER
SNOWFALL AMOUNTS. QUITE A CHALLENGING FORECAST RIGHT ON THE CUSP
OF HEADLINE THRESHOLDS.

THE EVENT DOES TAKE PLACE MAINLY FROM SUNDAY EVENING INTO THE EARLY
MORNING HOURS ON MONDAY DURING WHICH TIME THERE IS NOT MUCH TRAFFIC
ON THE ROAD. IS THIS A HIGH IMPACT EVENT THAT WARRANTS WARNINGS? A
QUESTION TO STRUGGLE WITH AS WARNINGS ARE NECESSARY WHEN WE ARE
CONFIDENT IN MEETING OR EXCEEDING 6+ INCH CRITERIA. YET THE QUESTION
IN FRONT OF US IS WHERE WILL THE HIGHER AMOUNTS OF SNOW FOCUS? HAVE
TO MAKE SOME SORT OF CALL...THE NEEDS OF THE MANY OUTWEIGH THE NEEDS
OF THE FEW.

ADVISORIES POSTED WHERE THERE IS HIGH CONFIDENCE OF SNOW BUT LIKELY
TO REMAIN BELOW THE 6-INCH THRESHOLD FOR WARNING. WATCHES CONTINUE
AND HAVE BEEN EXTENDED TO THE S-COAST TO COVER FOR THE UNCERTAINTY
OF THE AREA EITHER FALLING WITHIN OR IN EXCESS OF ADVISORY-LEVEL
SNOWS. AGAIN...6+ INCH AMOUNTS ARE ANTICIPATED BUT EXACTLY WHERE IS
UNCERTAIN.

5) CLOSING NOTES...

SOME CONCERN FOR THE EARLY MONDAY MORNING COMMUTE FOR E/SE MA AND
RI. WHILE MOST OF THE SNOW IS EXPECTED TO BE IMMEDIATELY OFFSHORE
WITH SUNRISE MONDAY...COMMUTERS COULD ENCOUNTER SLICK AND SLIPPERY
ROAD CONDITIONS. SNOW COULD POSSIBLY LINGER OVER SE MA SO THERE IS
THE POTENTIAL FOR REDUCED VISIBILITIES.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...

HIGHLIGHTS...

*  CONDITIONS IMPROVE MONDAY
*  ANOTHER STORM POSSIBLE TUE NIGHT INTO WED...WITH SNOW OR
   MIXED PRECIP LIKELY CHANGING TO RAIN
*  COLD AND DRY TOWARD THE END OF THE WEEK

OVERVIEW AND MODEL PREFERENCES...

ONE THING IS FOR CERTAIN...WITH LITTLE CHANGE IN THE NAO/AO AND
THE PNA EXPECTED TO REBOUND FROM NEGATIVE VALUES BACK TOWARD A
MORE NEUTRAL SOLUTION...THE COLD AIR AND LONGWAVE TROF LOOK TO
REMAIN THROUGH THE LONG TERM FORECAST. THE ONLY CAVEAT WILL BE IN
THE LOW LVLS ON WED...WHEN A ROBUST SW LLJ WILL ALLOW LOW-MID LVL
TEMPS TO WARM CLOSER TO ABOVE CLIMATOLOGICAL NORMALS. HOWEVER...
THE COLD AIR INITIALLY IN PLACE WILL LEAD TO P-TYPE ISSUES FOR THE
MID WEEK SYSTEM. ECMWF DETERMINISTIC REMAINS THE MOST ROBUST OF
THE OPERATIONAL MODELS...WITH HIGHER AMPLIFICATION IN THE FLOW
PATTERN THAN THE GFS AND UKMET. IT STARTS MUCH COLDER...BUT ENDS
MUCH WARMER. HOWEVER...DO NOTE THAT SOME OF THE GEFS AND ECENS
ENSEMBLES AGREE WITH THE ECMWF. THEREFORE...WILL BE USING THE
ENSEMBLE BLEND AS A BASELINE AS THIS TAKES INTO ACCOUNT BOTH THE
MORE PROGRESSIVE /AND ULTIMATELY LESS ROBUST WITH THE THERMAL
DIFFERENCES/ AND THE POTENTIAL FOR A MORE DYNAMIC SYSTEM. WILL USE
THIS BLEND THROUGH THE REMAINDER OF THE FORECAST AS WELL.

DETAILS...

MONDAY...

MORNING SNOWS COME TO AN END EARLY ACROSS E MA...AND FLURRIES
DISSIPATE THROUGH THE BERKSHIRES AND LITCHFIELD HILLS AS DRY NW
FLOW MOVES IN. BLUSTERY CONDITIONS EXPECTED...AND EVEN THROUGH
HIGHS WILL STILL BE MAKING IT INTO THE LOW-UPPER 30S...NW WINDS
WITH GUSTS 25-35 MPH AT TIMES WILL YIELD WIND CHILLS STRUGGLING
INTO THE LOW 20S.

MONDAY NIGHT INTO TUESDAY...

HIGH PRES WILL MOVE ACROSS THE REGION. DRY CONDITIONS DOMINATE
ALTHOUGH WITH TEMPS REMAINING BELOW NORMAL.

TUESDAY NIGHT INTO THURSDAY...

MODEL CONSENSUS IS NOW GENERALLY IN AGREEMENT THAT BOTH THE NRN
AND SRN STREAMS PHASE IN SOME FASHION ACROSS THE CENTRAL CONUS
WITH THE FORMATION OF LOW PRES WHICH IS EXPECTED TO SLIDE ACROSS
SRN CANADA. WARM FRONT WILL APPROACH...BUT GIVEN DEEP SNOWPACK THE
LOW LVL FRONT MAY ACTUAL STALL NEAR THE S COAST AS THE LOW MOVES
OVER AS THE UPPER WARM FRONT SLIDES INTO CENTRAL NEW ENGLAND. THIS
PRESENTS A GOOD OVERRUNNING SITUATION WITH STRONG 50-60 KT H92 LLJ
OUT OF THE SW. GIVEN THAT THIS SYSTEM IS ASSOCIATED WITH THE SRN
STREAM...IT ALSO CARRIES WITH IT A FAIR AMOUNT OF MOISTURE AS
PWATS LOOK TO REACH 2-3 STD DEVIATIONS ABOVE NORMAL

SO ALL IN ALL..PLENTY OF INGREDIENTS FOR HEAVY PRECIP ACROSS THE
AREA. THE QUESTION WILL BE TYPE...ALL GUIDANCE BEGIN COLD ENOUGH
FOR SNOW AT ONSET TUE NIGHT INTO EARLY WED. ECMWF WOULD SUGGEST
MUCH MORE AND BETTER LIFT IN THE SNOW GROWTH REGION...SO THERE IS
THAT TO CONSIDER. IN ANY CASE...WILL NEED TO AT LEAST WATCH FOR
POTENTIAL WARNING LEVEL SNOWFALL BEFORE THE WARM AIR BEGINS TO
BUILD IN FROM S TO N THROUGH THE DAY ON WED. EVEN THOUGH THE ECMWF
STARTS THE COLDEST...IT ENDS AS THE WARMEST SOLUTION...BRINGING
THE H92 +8C LINE ALL THE WAY INTO CENTRAL MA. SO WE DO EXPECT A
GRADUAL SHIFT TO A WINTRY MIX INCLUDING SLEET AND FREEZING RAIN
FOR A TIME GIVEN THE DEEP SNOWPACK ACROSS THE REGION. SOME AREAS
OF WRN MA...AND THE HILLS OF NRN CT MAY ACTUALLY STAY AS A MIX OF
SLEET FREEZING RAIN AND EVEN MAYBE SOME SNOW GIVEN THAT THE SFC
WARM FRONT MAY STALL. WILL HAVE TO WATCH FOR ICY CONDITIONS WITH
AS MUCH AS A QUARTER INCH OF ICE NOT OUT OF THE QUESTION WHERE IT
DOESN/T SWITCH TO RAIN WITH MELTING /BEST CHANCE OF RAIN/MELT IS
IN RI/CT AND PORTIONS OF MASS E OF I-495 AND S OF THE MASS PIKE/.
HEAVY RAIN A THREAT TOO GIVEN UPPER LVL INSTABILITY AND ROBUST
LLJ...SO WHERE MELTING AND HEAVY RAIN ARE OBSERVED...POOR DRAINAGE
FLOODING IS A POSSIBILITY WHERE SNOW CLOGS AREA DRAINS.

THIS HEAVY MIXED PRECIP EVENT COULD LINGER INTO THU...THE MORE
AMPLIFIED ECMWF AND SEVERAL ECENS/GEFS MEMBERS SUGGEST THAT THE
LEFTOVER COLD FRONT STALLS WITH YET ANOTHER WEAK WAVE OF LOW PRES
MOVING THROUGH THU. OTHER SOLUTIONS ARE MORE PROGRESSIVE AND HAVE
LESS QPF /SNOW POTENTIALLY/ ON THE BACK END. HOWEVER...BY THU
AFTERNOON/EVENING...CONDITIONS SHOULD BE IMPROVING /ALTHOUGH WITH
RAPID TEMPERATURE DROP/.

LATE NEXT WEEK...

EVEN THOUGH THERE IS UNCERTAINTY WITH HOW AMPLIFIED THE PATTERN
IS BY LATE WEEK. IT APPEARS A PERIOD OF DRY BUT COLD WX IS LIKELY
AS ARCTIC AIR ONCE AGAIN SHIFTS IN BEHIND THE EXITING MID WEEK
SYSTEM.

&&

.AVIATION /20Z SATURDAY THROUGH THURSDAY/...

FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /THROUGH MONDAY MORNING/...

21Z UPDATE...

TONIGHT THROUGH SUNDAY MIDDAY...HIGH CONFIDENCE.

VFR. LOWERING AND THICKENING CLOUDS SUNDAY MORNING INTO MIDDAY.
LOW-END VFR TO W-TERMINALS BY END OF PERIOD.

SUNDAY AFTERNOON INTO MONDAY MORNING...MODERATE CONFIDENCE.

SNOW OVERSPREADS THE REGION W-E. CIGS/VSBYS DETERIORATE TO MVFR-
IFR BY EARLY EVENING...WIDESPREAD IFR-LIFR SUNDAY NIGHT. SN TO MIX
WITH OR CHANGE TO FZRA ACROSS OFFSHORE ISLAND TERMINALS OVERNIGHT.
PRECIP ENDS W-E TOWARD DAYBREAK MONDAY....CONDITIONS IMPROVE.

KBOS TAF...MODERATE CONFIDENCE. TRENDS CERTAIN BUT NOT SO MUCH THE
ACTUAL TIMING OF IMPACTS.

KBDL TAF...MODERATE CONFIDENCE. TRENDS CERTAIN BUT NOT SO MUCH
THE ACTUAL TIMING OF IMPACTS.

OUTLOOK...MONDAY THROUGH WEDNESDAY...

MONDAY...HIGH CONFIDENCE.

CONDITIONS IMPROVE EARLY FROM IFR/MVFR IN SNOWS AND LOW CIGS...
WITH VFR EXPECTED EVERYWHERE BY AFTERNOON. NW WINDS IN THE
AFTERNOON WITH GUSTS 25-30 KT.

MON NIGHT INTO TUE...HIGH CONFIDENCE.

MAINLY VFR. GRADUALLY LOWERING CIGS ON TUE.

TUE NIGHT INTO WED...MODERATE CONFIDENCE.

MIXED WINTRY PRECIP LIKELY STARTS AS ALL SNOW...TRANSITIONS TO A
MIX OF SLEET AND FREEZING RAIN...THEN TO ALL RAIN DURING THE DAY
ON WED. SOME SNOW AND ICE ACCUMULATIONS ARE LIKELY WITH IFR OR
POTENTIALLY EVEN LIFR CONDITIONS AT TIMES.

&&

.MARINE...

FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /THROUGH MONDAY MORNING/...HIGH CONFIDENCE.

HIGH PRESSURE NEARBY WILL KEEP WINDS/SEAS WELL BELOW SMALL CRAFT
ADVISORY THRESHOLDS INTO SUNDAY MORNING. A WEAK WAVE OF LOW
PRESSURE MOVES ACROSS THE WATERS LATE SUNDAY INTO SUNDAY NIGHT...
BUT WEAK PRESSURE GRADIENT SHOULD KEEP WINDS/SEAS BELOW SMALL
CRAFT THRESHOLDS.

OUTLOOK...MONDAY THROUGH WEDNESDAY...

MONDAY INTO MONDAY NIGHT...HIGH CONFIDENCE.

SW WINDS SHIFT TO THE NW DURING THE DAYLIGHT HOURS AS A COLD
FRONT SWEEPS ACROSS THE WATERS. ONCE WINDS SHIFT NW IN THE
AFTERNOON EXPECT GALE FORCE GUSTS 35-40KT. COLDER AIR TUE NIGHT
COULD LEAD TO LIGHT FREEZING SPRAY.

TUESDAY...MODERATE CONFIDENCE.

WINDS GRADUALLY DIMINISH OUT OF THE W-NW BUT SEAS ARE LIKELY TO
REMAIN ELEVATED 5-8FT ON THE OCEAN WATERS. SMALL CRAFT ADVISORIES
WILL LIKELY BE NEEDED.

TUESDAY NIGHT INTO WEDNESDAY...MODERATE CONFIDENCE.

SNOW CHANGES TO RAIN TUE NIGHT WITH LOW VSBYS OVER THE WATERS.
WINDS OUT OF THE S MAINLY AROUND 25-30 KT AT MOST. SEAS BUILD
12-15 FT BY DAYTIME ON WED ON SE OCEAN WATERS. SMALL CRAFT
ADVISORIES WILL LIKELY BE NEEDED.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...

CT...WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY
     MORNING FOR CTZ002>004.
MA...WINTER WEATHER ADVISORY FROM NOON SUNDAY TO 7 AM EST MONDAY
     FOR MAZ002>008-010-014-023-024-026.
     WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY
     MORNING FOR MAZ009-011>013-015>022.
RI...WINTER WEATHER ADVISORY FROM NOON SUNDAY TO 7 AM EST MONDAY
     FOR RIZ008.
     WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY
     MORNING FOR RIZ001>007.
MARINE...NONE.

&&

$$

SYNOPSIS...DOODY/SIPPRELL
NEAR TERM...SIPPRELL
SHORT TERM...SIPPRELL
LONG TERM...DOODY
AVIATION...DOODY/SIPPRELL
MARINE...DOODY/SIPPRELL




000
FXUS61 KBOX 282032
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
332 PM EST SAT FEB 28 2015

.SYNOPSIS...

A FAST MOVING LOW PRESSURE SYSTEM WILL BRING ACCUMULATING SNOW TO
THE REGION LATE SUNDAY INTO SUNDAY NIGHT...WITH THE HIGHEST AMOUNTS
EXPECTED SOUTH OF THE MASSACHUSETTS TURNPIKE AND AWAY FROM THE
IMMEDIATE SOUTH COAST. ANOTHER STORM IS LIKELY TUESDAY NIGHT INTO
WEDNESDAY...WITH SNOW AND MIXED PRECIPITATION LIKELY CHANGING TO
RAIN. COLD AND DRY CONDITIONS RETURN FOR THE END OF NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...

INTO THIS EVENING...

HIGH PRESSURE PUSHING E INTO THE REGION. TEMPERATURES EXPECTED TO
QUICKLY DROP WITH MOSTLY CLEAR CONDITIONS AND LIGHT WINDS.

TONIGHT...

COLD. CONDITIONS WILL BE JUST RIGHT TO ALLOW FOR GOOD RADIATIONAL
COOLING...ESPECIALLY TO THE E WHERE THE IMPACT OF INCREASING MID- TO
HIGH-CLOUDS LATE IN THE PERIOD WILL BE LESS. LOOKING AT SUB-ZERO
LOWS FOR LOW-LYING AREAS WHERE COLD-AIR DRAINAGE EFFECTS OFF THE
HIGH TERRAIN ARE MAXIMIZED. HIGH-TERRAIN SHOULD REMAIN AT OR ABOVE
ZERO.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...

*/ SUNDAY MORNING INTO MIDDAY...

QUIET WEATHER. CLOUDS THICKENING AS WINDS INCREASE OUT OF THE S.
WILL SEE TEMPERATURES GRADUALLY MODERATE INTO THE MID- TO UPPER-20S.

*/ SUNDAY AFTERNOON INTO EARLY MONDAY MORNING...

1) HIGHLIGHTS...

 - SNOW SUNDAY AFTERNOON INTO MONDAY MORNING
 - GREATEST INTENSITY SUNDAY EVENING AND OVERNIGHT
 - 6+ INCH SNOWFALLS EXPECTED BUT EXACTLY WHERE REMAINS UNCERTAIN
 - ANNOYINGLY...FORECAST GUIDANCE CONTINUES TO WOBBLE

1) OVERVIEW...

BROAD ISENTROPIC OVER-RUNNING EVENT OF GULF MOISTURE ALONG THE 275-
295K SURFACES AMPLIFIED BY A N-STREAM IMPULSE DURING THE TIMEFRAME
POSSIBLY INVOKING AN AREA OF LOW PRESSURE THAT SKIRTS ALONG THE S-
COAST SUBSEQUENTLY ENHANCING LOW-LEVEL WIND PROFILE. LIGHT-MODERATE
SNOWFALL IS ANTICIPATED WITH LOCALLY HEAVIER AMOUNTS. THE INTENSE
PORTION OF SNOWFALL IS EXPECTED SUNDAY EVENING AND OVERNIGHT ENDING
EARLY MONDAY MORNING.

MODEL PREFERENCE GIVEN TO THE ECMWF/GFS/REGIONAL CANADIAN WHICH WILL
SERVE AS THE CONSENSUS OF GUIDANCE FOR THIS DISCUSSION. THE 28.12Z
NAM WAS CONSIDERED AN OUTLIER WITH ITS AGGRESSIVE-MODE AND SECONDARY
LOW DEVELOPMENT JUST OFFSHORE.

2) PRECIPITATION-TYPE...

EVALUATING THERMAL FIELDS...BLEND OF FORECAST CONSENSUS PUTS THE
-2C H925 ISOTHERM W-E ACROSS S-TIER OF CT/RI AND ACROSS SE MA WITH
THE 0C H85 ISOTHERM JUST S OF LONG-ISLAND AND NANTUCKET COASTLINES.
THE CONSENSUS OF 1000-850 MB CRITICAL THICKNESSES LAYS RIGHT ALONG
THE IMMEDIATE S-COAST OF LONG-ISLAND AND CAPE COD.

AN ALL SNOW-EVENT WHEN CONSIDERING DYNAMIC-COOLING/WETBULBING OF THE
LOW-LEVELS AHEAD OF THE EVENT. THERE IS PERHAPS A CHANCE OF A BRIEF
MIX-OVER TO RAIN/FREEZING RAIN ACROSS THE CAPE AND ISLANDS AS S-FLOW
AT THE SURFACE IS POSSIBLY ABLE TO NUDGE ABOVE-FREEZING TEMPERATURES
N. YET AS WE ARE IN A FROZEN TUNDRA...WITH ANY RAIN IT WOULD LIKELY
FREEZE ON SURFACES WHICH ARE QUITE COLD. THUS FREEZING RAIN PREVAILS
OVER RAIN IN THE FORECAST.

3) SNOWFALL...

FORECAST CONSENSUS OF A 0.3-0.6 N-S PRECIPITATION EVENT WITH A N-S
SNOW-TO-LIQUID RATIO GRADIENT RANGING FROM 15:1 TO 10:1 YIELDS HIGH-
END SNOW ADVISORY CRITERIA WITH SNOWFALL AMOUNTS RANGING ON AVERAGE
AROUND 3-6 INCHES. AREAS OF 6+ INCHES ARE EXPECTED...ESPECIALLY FROM
CENTRAL-CT E INTO SE-MA /INCLUDING THE UPPER-CAPE/. A CHALLENGE AND
A LOT OF UNCERTAINTY WITH RESPECT TO HEADLINES AND DECISION-MAKING.

EVALUATING LOW-LEVEL THERMAL PROFILES TOWARDS SNOW-TO-LIQUID RATIOS
DERIVED VIA A COBB-TECHNIQUE...WITH THE GREATEST LIFT OCCURRING
JUST BENEATH OR WITHIN THE DENDRITIC-GROWTH ZONE BASED ON A
CONSENSUS OF BUFKIT GFS PROFILES...ESPECIALLY IN HEAVIER- PRECIP
AREAS...BELIEVE THE SNOW WILL RANGE SOMEWHERE BETWEEN A WET AND
FLUFFY SNOW. SNOW PROPERTIES FROM FLUFFY TO WET LIKELY SIMILAR TO
THE N-S GRADIENT AS OUTLINED ABOVE.

4) HEADLINES...

HATE A WOBBLING FORECAST WHICH IS TYPICAL WITH SUCH SMALL EVENTS.
UNCERTAINTY DERIVES FROM LOW-LEVEL THERMAL PROFILES AND PRECIP
AMOUNTS. SURELY EXPECTING SNOW...BUT WITH ANY SHIFT N-S OF COLDER
AIR AND/OR PRECIPITATION AMOUNTS RESULTS IN AREAS SHIFTING FROM
ADVISORY TO WARNING...OR VICE VERSA. ENOUGH TO JUST PULL YOUR HAIR
OUT. THEN THERE IS THE TIMING OF THE SYSTEM THAT HAS SPED UP
SLIGHTLY. A SHORTER RESIDENCE TIME OF COURSE WOULD YIELD LESSER
SNOWFALL AMOUNTS. QUITE A CHALLENGING FORECAST RIGHT ON THE CUSP
OF HEADLINE THRESHOLDS.

THE EVENT DOES TAKE PLACE MAINLY FROM SUNDAY EVENING INTO THE EARLY
MORNING HOURS ON MONDAY DURING WHICH TIME THERE IS NOT MUCH TRAFFIC
ON THE ROAD. IS THIS A HIGH IMPACT EVENT THAT WARRANTS WARNINGS? A
QUESTION TO STRUGGLE WITH AS WARNINGS ARE NECESSARY WHEN WE ARE
CONFIDENT IN MEETING OR EXCEEDING 6+ INCH CRITERIA. YET THE QUESTION
IN FRONT OF US IS WHERE WILL THE HIGHER AMOUNTS OF SNOW FOCUS? HAVE
TO MAKE SOME SORT OF CALL...THE NEEDS OF THE MANY OUTWEIGH THE NEEDS
OF THE FEW.

ADVISORIES POSTED WHERE THERE IS HIGH CONFIDENCE OF SNOW BUT LIKELY
TO REMAIN BELOW THE 6-INCH THRESHOLD FOR WARNING. WATCHES CONTINUE
AND HAVE BEEN EXTENDED TO THE S-COAST TO COVER FOR THE UNCERTAINTY
OF THE AREA EITHER FALLING WITHIN OR IN EXCESS OF ADVISORY-LEVEL
SNOWS. AGAIN...6+ INCH AMOUNTS ARE ANTICIPATED BUT EXACTLY WHERE IS
UNCERTAIN.

5) CLOSING NOTES...

SOME CONCERN FOR THE EARLY MONDAY MORNING COMMUTE FOR E/SE MA AND
RI. WHILE MOST OF THE SNOW IS EXPECTED TO BE IMMEDIATELY OFFSHORE
WITH SUNRISE MONDAY...COMMUTERS COULD ENCOUNTER SLICK AND SLIPPERY
ROAD CONDITIONS. SNOW COULD POSSIBLY LINGER OVER SE MA SO THERE IS
THE POTENTIAL FOR REDUCED VISIBILITIES.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...

HIGHLIGHTS...

*  CONDITIONS IMPROVE MONDAY
*  ANOTHER STORM POSSIBLE TUE NIGHT INTO WED...WITH SNOW OR
   MIXED PRECIP LIKELY CHANGING TO RAIN
*  COLD AND DRY TOWARD THE END OF THE WEEK

OVERVIEW AND MODEL PREFERENCES...

ONE THING IS FOR CERTAIN...WITH LITTLE CHANGE IN THE NAO/AO AND
THE PNA EXPECTED TO REBOUND FROM NEGATIVE VALUES BACK TOWARD A
MORE NEUTRAL SOLUTION...THE COLD AIR AND LONGWAVE TROF LOOK TO
REMAIN THROUGH THE LONG TERM FORECAST. THE ONLY CAVEAT WILL BE IN
THE LOW LVLS ON WED...WHEN A ROBUST SW LLJ WILL ALLOW LOW-MID LVL
TEMPS TO WARM CLOSER TO ABOVE CLIMATOLOGICAL NORMALS. HOWEVER...
THE COLD AIR INITIALLY IN PLACE WILL LEAD TO P-TYPE ISSUES FOR THE
MID WEEK SYSTEM. ECMWF DETERMINISTIC REMAINS THE MOST ROBUST OF
THE OPERATIONAL MODELS...WITH HIGHER AMPLIFICATION IN THE FLOW
PATTERN THAN THE GFS AND UKMET. IT STARTS MUCH COLDER...BUT ENDS
MUCH WARMER. HOWEVER...DO NOTE THAT SOME OF THE GEFS AND ECENS
ENSEMBLES AGREE WITH THE ECMWF. THEREFORE...WILL BE USING THE
ENSEMBLE BLEND AS A BASELINE AS THIS TAKES INTO ACCOUNT BOTH THE
MORE PROGRESSIVE /AND ULTIMATELY LESS ROBUST WITH THE THERMAL
DIFFERENCES/ AND THE POTENTIAL FOR A MORE DYNAMIC SYSTEM. WILL USE
THIS BLEND THROUGH THE REMAINDER OF THE FORECAST AS WELL.

DETAILS...

MONDAY...

MORNING SNOWS COME TO AN END EARLY ACROSS E MA...AND FLURRIES
DISSIPATE THROUGH THE BERKSHIRES AND LITCHFIELD HILLS AS DRY NW
FLOW MOVES IN. BLUSTERY CONDITIONS EXPECTED...AND EVEN THROUGH
HIGHS WILL STILL BE MAKING IT INTO THE LOW-UPPER 30S...NW WINDS
WITH GUSTS 25-35 MPH AT TIMES WILL YIELD WIND CHILLS STRUGGLING
INTO THE LOW 20S.

MONDAY NIGHT INTO TUESDAY...

HIGH PRES WILL MOVE ACROSS THE REGION. DRY CONDITIONS DOMINATE
ALTHOUGH WITH TEMPS REMAINING BELOW NORMAL.

TUESDAY NIGHT INTO THURSDAY...

MODEL CONSENSUS IS NOW GENERALLY IN AGREEMENT THAT BOTH THE NRN
AND SRN STREAMS PHASE IN SOME FASHION ACROSS THE CENTRAL CONUS
WITH THE FORMATION OF LOW PRES WHICH IS EXPECTED TO SLIDE ACROSS
SRN CANADA. WARM FRONT WILL APPROACH...BUT GIVEN DEEP SNOWPACK THE
LOW LVL FRONT MAY ACTUAL STALL NEAR THE S COAST AS THE LOW MOVES
OVER AS THE UPPER WARM FRONT SLIDES INTO CENTRAL NEW ENGLAND. THIS
PRESENTS A GOOD OVERRUNNING SITUATION WITH STRONG 50-60 KT H92 LLJ
OUT OF THE SW. GIVEN THAT THIS SYSTEM IS ASSOCIATED WITH THE SRN
STREAM...IT ALSO CARRIES WITH IT A FAIR AMOUNT OF MOISTURE AS
PWATS LOOK TO REACH 2-3 STD DEVIATIONS ABOVE NORMAL

SO ALL IN ALL..PLENTY OF INGREDIENTS FOR HEAVY PRECIP ACROSS THE
AREA. THE QUESTION WILL BE TYPE...ALL GUIDANCE BEGIN COLD ENOUGH
FOR SNOW AT ONSET TUE NIGHT INTO EARLY WED. ECMWF WOULD SUGGEST
MUCH MORE AND BETTER LIFT IN THE SNOW GROWTH REGION...SO THERE IS
THAT TO CONSIDER. IN ANY CASE...WILL NEED TO AT LEAST WATCH FOR
POTENTIAL WARNING LEVEL SNOWFALL BEFORE THE WARM AIR BEGINS TO
BUILD IN FROM S TO N THROUGH THE DAY ON WED. EVEN THOUGH THE ECMWF
STARTS THE COLDEST...IT ENDS AS THE WARMEST SOLUTION...BRINGING
THE H92 +8C LINE ALL THE WAY INTO CENTRAL MA. SO WE DO EXPECT A
GRADUAL SHIFT TO A WINTRY MIX INCLUDING SLEET AND FREEZING RAIN
FOR A TIME GIVEN THE DEEP SNOWPACK ACROSS THE REGION. SOME AREAS
OF WRN MA...AND THE HILLS OF NRN CT MAY ACTUALLY STAY AS A MIX OF
SLEET FREEZING RAIN AND EVEN MAYBE SOME SNOW GIVEN THAT THE SFC
WARM FRONT MAY STALL. WILL HAVE TO WATCH FOR ICY CONDITIONS WITH
AS MUCH AS A QUARTER INCH OF ICE NOT OUT OF THE QUESTION WHERE IT
DOESN/T SWITCH TO RAIN WITH MELTING /BEST CHANCE OF RAIN/MELT IS
IN RI/CT AND PORTIONS OF MASS E OF I-495 AND S OF THE MASS PIKE/.
HEAVY RAIN A THREAT TOO GIVEN UPPER LVL INSTABILITY AND ROBUST
LLJ...SO WHERE MELTING AND HEAVY RAIN ARE OBSERVED...POOR DRAINAGE
FLOODING IS A POSSIBILITY WHERE SNOW CLOGS AREA DRAINS.

THIS HEAVY MIXED PRECIP EVENT COULD LINGER INTO THU...THE MORE
AMPLIFIED ECMWF AND SEVERAL ECENS/GEFS MEMBERS SUGGEST THAT THE
LEFTOVER COLD FRONT STALLS WITH YET ANOTHER WEAK WAVE OF LOW PRES
MOVING THROUGH THU. OTHER SOLUTIONS ARE MORE PROGRESSIVE AND HAVE
LESS QPF /SNOW POTENTIALLY/ ON THE BACK END. HOWEVER...BY THU
AFTERNOON/EVENING...CONDITIONS SHOULD BE IMPROVING /ALTHOUGH WITH
RAPID TEMPERATURE DROP/.

LATE NEXT WEEK...

EVEN THOUGH THERE IS UNCERTAINTY WITH HOW AMPLIFIED THE PATTERN
IS BY LATE WEEK. IT APPEARS A PERIOD OF DRY BUT COLD WX IS LIKELY
AS ARCTIC AIR ONCE AGAIN SHIFTS IN BEHIND THE EXITING MID WEEK
SYSTEM.

&&

.AVIATION /20Z SATURDAY THROUGH THURSDAY/...

FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /THROUGH MONDAY MORNING/...

21Z UPDATE...

TONIGHT THROUGH SUNDAY MIDDAY...HIGH CONFIDENCE.

VFR. LOWERING AND THICKENING CLOUDS SUNDAY MORNING INTO MIDDAY.
LOW-END VFR TO W-TERMINALS BY END OF PERIOD.

SUNDAY AFTERNOON INTO MONDAY MORNING...MODERATE CONFIDENCE.

SNOW OVERSPREADS THE REGION W-E. CIGS/VSBYS DETERIORATE TO MVFR-
IFR BY EARLY EVENING...WIDESPREAD IFR-LIFR SUNDAY NIGHT. SN TO MIX
WITH OR CHANGE TO FZRA ACROSS OFFSHORE ISLAND TERMINALS OVERNIGHT.
PRECIP ENDS W-E TOWARD DAYBREAK MONDAY....CONDITIONS IMPROVE.

KBOS TAF...MODERATE CONFIDENCE. TRENDS CERTAIN BUT NOT SO MUCH THE
ACTUAL TIMING OF IMPACTS.

KBDL TAF...MODERATE CONFIDENCE. TRENDS CERTAIN BUT NOT SO MUCH
THE ACTUAL TIMING OF IMPACTS.

OUTLOOK...MONDAY THROUGH WEDNESDAY...

MONDAY...HIGH CONFIDENCE.

CONDITIONS IMPROVE EARLY FROM IFR/MVFR IN SNOWS AND LOW CIGS...
WITH VFR EXPECTED EVERYWHERE BY AFTERNOON. NW WINDS IN THE
AFTERNOON WITH GUSTS 25-30 KT.

MON NIGHT INTO TUE...HIGH CONFIDENCE.

MAINLY VFR. GRADUALLY LOWERING CIGS ON TUE.

TUE NIGHT INTO WED...MODERATE CONFIDENCE.

MIXED WINTRY PRECIP LIKELY STARTS AS ALL SNOW...TRANSITIONS TO A
MIX OF SLEET AND FREEZING RAIN...THEN TO ALL RAIN DURING THE DAY
ON WED. SOME SNOW AND ICE ACCUMULATIONS ARE LIKELY WITH IFR OR
POTENTIALLY EVEN LIFR CONDITIONS AT TIMES.

&&

.MARINE...

FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /THROUGH MONDAY MORNING/...HIGH CONFIDENCE.

HIGH PRESSURE NEARBY WILL KEEP WINDS/SEAS WELL BELOW SMALL CRAFT
ADVISORY THRESHOLDS INTO SUNDAY MORNING. A WEAK WAVE OF LOW
PRESSURE MOVES ACROSS THE WATERS LATE SUNDAY INTO SUNDAY NIGHT...
BUT WEAK PRESSURE GRADIENT SHOULD KEEP WINDS/SEAS BELOW SMALL
CRAFT THRESHOLDS.

OUTLOOK...MONDAY THROUGH WEDNESDAY...

MONDAY INTO MONDAY NIGHT...HIGH CONFIDENCE.

SW WINDS SHIFT TO THE NW DURING THE DAYLIGHT HOURS AS A COLD
FRONT SWEEPS ACROSS THE WATERS. ONCE WINDS SHIFT NW IN THE
AFTERNOON EXPECT GALE FORCE GUSTS 35-40KT. COLDER AIR TUE NIGHT
COULD LEAD TO LIGHT FREEZING SPRAY.

TUESDAY...MODERATE CONFIDENCE.

WINDS GRADUALLY DIMINISH OUT OF THE W-NW BUT SEAS ARE LIKELY TO
REMAIN ELEVATED 5-8FT ON THE OCEAN WATERS. SMALL CRAFT ADVISORIES
WILL LIKELY BE NEEDED.

TUESDAY NIGHT INTO WEDNESDAY...MODERATE CONFIDENCE.

SNOW CHANGES TO RAIN TUE NIGHT WITH LOW VSBYS OVER THE WATERS.
WINDS OUT OF THE S MAINLY AROUND 25-30 KT AT MOST. SEAS BUILD
12-15 FT BY DAYTIME ON WED ON SE OCEAN WATERS. SMALL CRAFT
ADVISORIES WILL LIKELY BE NEEDED.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...

CT...WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY
     MORNING FOR CTZ002>004.
MA...WINTER WEATHER ADVISORY FROM NOON SUNDAY TO 7 AM EST MONDAY
     FOR MAZ002>008-010-014-023-024-026.
     WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY
     MORNING FOR MAZ009-011>013-015>022.
RI...WINTER WEATHER ADVISORY FROM NOON SUNDAY TO 7 AM EST MONDAY
     FOR RIZ008.
     WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY
     MORNING FOR RIZ001>007.
MARINE...NONE.

&&

$$

SYNOPSIS...DOODY/SIPPRELL
NEAR TERM...SIPPRELL
SHORT TERM...SIPPRELL
LONG TERM...DOODY
AVIATION...DOODY/SIPPRELL
MARINE...DOODY/SIPPRELL




000
FXUS61 KBOX 282032
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
332 PM EST SAT FEB 28 2015

.SYNOPSIS...

A FAST MOVING LOW PRESSURE SYSTEM WILL BRING ACCUMULATING SNOW TO
THE REGION LATE SUNDAY INTO SUNDAY NIGHT...WITH THE HIGHEST AMOUNTS
EXPECTED SOUTH OF THE MASSACHUSETTS TURNPIKE AND AWAY FROM THE
IMMEDIATE SOUTH COAST. ANOTHER STORM IS LIKELY TUESDAY NIGHT INTO
WEDNESDAY...WITH SNOW AND MIXED PRECIPITATION LIKELY CHANGING TO
RAIN. COLD AND DRY CONDITIONS RETURN FOR THE END OF NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...

INTO THIS EVENING...

HIGH PRESSURE PUSHING E INTO THE REGION. TEMPERATURES EXPECTED TO
QUICKLY DROP WITH MOSTLY CLEAR CONDITIONS AND LIGHT WINDS.

TONIGHT...

COLD. CONDITIONS WILL BE JUST RIGHT TO ALLOW FOR GOOD RADIATIONAL
COOLING...ESPECIALLY TO THE E WHERE THE IMPACT OF INCREASING MID- TO
HIGH-CLOUDS LATE IN THE PERIOD WILL BE LESS. LOOKING AT SUB-ZERO
LOWS FOR LOW-LYING AREAS WHERE COLD-AIR DRAINAGE EFFECTS OFF THE
HIGH TERRAIN ARE MAXIMIZED. HIGH-TERRAIN SHOULD REMAIN AT OR ABOVE
ZERO.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...

*/ SUNDAY MORNING INTO MIDDAY...

QUIET WEATHER. CLOUDS THICKENING AS WINDS INCREASE OUT OF THE S.
WILL SEE TEMPERATURES GRADUALLY MODERATE INTO THE MID- TO UPPER-20S.

*/ SUNDAY AFTERNOON INTO EARLY MONDAY MORNING...

1) HIGHLIGHTS...

 - SNOW SUNDAY AFTERNOON INTO MONDAY MORNING
 - GREATEST INTENSITY SUNDAY EVENING AND OVERNIGHT
 - 6+ INCH SNOWFALLS EXPECTED BUT EXACTLY WHERE REMAINS UNCERTAIN
 - ANNOYINGLY...FORECAST GUIDANCE CONTINUES TO WOBBLE

1) OVERVIEW...

BROAD ISENTROPIC OVER-RUNNING EVENT OF GULF MOISTURE ALONG THE 275-
295K SURFACES AMPLIFIED BY A N-STREAM IMPULSE DURING THE TIMEFRAME
POSSIBLY INVOKING AN AREA OF LOW PRESSURE THAT SKIRTS ALONG THE S-
COAST SUBSEQUENTLY ENHANCING LOW-LEVEL WIND PROFILE. LIGHT-MODERATE
SNOWFALL IS ANTICIPATED WITH LOCALLY HEAVIER AMOUNTS. THE INTENSE
PORTION OF SNOWFALL IS EXPECTED SUNDAY EVENING AND OVERNIGHT ENDING
EARLY MONDAY MORNING.

MODEL PREFERENCE GIVEN TO THE ECMWF/GFS/REGIONAL CANADIAN WHICH WILL
SERVE AS THE CONSENSUS OF GUIDANCE FOR THIS DISCUSSION. THE 28.12Z
NAM WAS CONSIDERED AN OUTLIER WITH ITS AGGRESSIVE-MODE AND SECONDARY
LOW DEVELOPMENT JUST OFFSHORE.

2) PRECIPITATION-TYPE...

EVALUATING THERMAL FIELDS...BLEND OF FORECAST CONSENSUS PUTS THE
-2C H925 ISOTHERM W-E ACROSS S-TIER OF CT/RI AND ACROSS SE MA WITH
THE 0C H85 ISOTHERM JUST S OF LONG-ISLAND AND NANTUCKET COASTLINES.
THE CONSENSUS OF 1000-850 MB CRITICAL THICKNESSES LAYS RIGHT ALONG
THE IMMEDIATE S-COAST OF LONG-ISLAND AND CAPE COD.

AN ALL SNOW-EVENT WHEN CONSIDERING DYNAMIC-COOLING/WETBULBING OF THE
LOW-LEVELS AHEAD OF THE EVENT. THERE IS PERHAPS A CHANCE OF A BRIEF
MIX-OVER TO RAIN/FREEZING RAIN ACROSS THE CAPE AND ISLANDS AS S-FLOW
AT THE SURFACE IS POSSIBLY ABLE TO NUDGE ABOVE-FREEZING TEMPERATURES
N. YET AS WE ARE IN A FROZEN TUNDRA...WITH ANY RAIN IT WOULD LIKELY
FREEZE ON SURFACES WHICH ARE QUITE COLD. THUS FREEZING RAIN PREVAILS
OVER RAIN IN THE FORECAST.

3) SNOWFALL...

FORECAST CONSENSUS OF A 0.3-0.6 N-S PRECIPITATION EVENT WITH A N-S
SNOW-TO-LIQUID RATIO GRADIENT RANGING FROM 15:1 TO 10:1 YIELDS HIGH-
END SNOW ADVISORY CRITERIA WITH SNOWFALL AMOUNTS RANGING ON AVERAGE
AROUND 3-6 INCHES. AREAS OF 6+ INCHES ARE EXPECTED...ESPECIALLY FROM
CENTRAL-CT E INTO SE-MA /INCLUDING THE UPPER-CAPE/. A CHALLENGE AND
A LOT OF UNCERTAINTY WITH RESPECT TO HEADLINES AND DECISION-MAKING.

EVALUATING LOW-LEVEL THERMAL PROFILES TOWARDS SNOW-TO-LIQUID RATIOS
DERIVED VIA A COBB-TECHNIQUE...WITH THE GREATEST LIFT OCCURRING
JUST BENEATH OR WITHIN THE DENDRITIC-GROWTH ZONE BASED ON A
CONSENSUS OF BUFKIT GFS PROFILES...ESPECIALLY IN HEAVIER- PRECIP
AREAS...BELIEVE THE SNOW WILL RANGE SOMEWHERE BETWEEN A WET AND
FLUFFY SNOW. SNOW PROPERTIES FROM FLUFFY TO WET LIKELY SIMILAR TO
THE N-S GRADIENT AS OUTLINED ABOVE.

4) HEADLINES...

HATE A WOBBLING FORECAST WHICH IS TYPICAL WITH SUCH SMALL EVENTS.
UNCERTAINTY DERIVES FROM LOW-LEVEL THERMAL PROFILES AND PRECIP
AMOUNTS. SURELY EXPECTING SNOW...BUT WITH ANY SHIFT N-S OF COLDER
AIR AND/OR PRECIPITATION AMOUNTS RESULTS IN AREAS SHIFTING FROM
ADVISORY TO WARNING...OR VICE VERSA. ENOUGH TO JUST PULL YOUR HAIR
OUT. THEN THERE IS THE TIMING OF THE SYSTEM THAT HAS SPED UP
SLIGHTLY. A SHORTER RESIDENCE TIME OF COURSE WOULD YIELD LESSER
SNOWFALL AMOUNTS. QUITE A CHALLENGING FORECAST RIGHT ON THE CUSP
OF HEADLINE THRESHOLDS.

THE EVENT DOES TAKE PLACE MAINLY FROM SUNDAY EVENING INTO THE EARLY
MORNING HOURS ON MONDAY DURING WHICH TIME THERE IS NOT MUCH TRAFFIC
ON THE ROAD. IS THIS A HIGH IMPACT EVENT THAT WARRANTS WARNINGS? A
QUESTION TO STRUGGLE WITH AS WARNINGS ARE NECESSARY WHEN WE ARE
CONFIDENT IN MEETING OR EXCEEDING 6+ INCH CRITERIA. YET THE QUESTION
IN FRONT OF US IS WHERE WILL THE HIGHER AMOUNTS OF SNOW FOCUS? HAVE
TO MAKE SOME SORT OF CALL...THE NEEDS OF THE MANY OUTWEIGH THE NEEDS
OF THE FEW.

ADVISORIES POSTED WHERE THERE IS HIGH CONFIDENCE OF SNOW BUT LIKELY
TO REMAIN BELOW THE 6-INCH THRESHOLD FOR WARNING. WATCHES CONTINUE
AND HAVE BEEN EXTENDED TO THE S-COAST TO COVER FOR THE UNCERTAINTY
OF THE AREA EITHER FALLING WITHIN OR IN EXCESS OF ADVISORY-LEVEL
SNOWS. AGAIN...6+ INCH AMOUNTS ARE ANTICIPATED BUT EXACTLY WHERE IS
UNCERTAIN.

5) CLOSING NOTES...

SOME CONCERN FOR THE EARLY MONDAY MORNING COMMUTE FOR E/SE MA AND
RI. WHILE MOST OF THE SNOW IS EXPECTED TO BE IMMEDIATELY OFFSHORE
WITH SUNRISE MONDAY...COMMUTERS COULD ENCOUNTER SLICK AND SLIPPERY
ROAD CONDITIONS. SNOW COULD POSSIBLY LINGER OVER SE MA SO THERE IS
THE POTENTIAL FOR REDUCED VISIBILITIES.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...

HIGHLIGHTS...

*  CONDITIONS IMPROVE MONDAY
*  ANOTHER STORM POSSIBLE TUE NIGHT INTO WED...WITH SNOW OR
   MIXED PRECIP LIKELY CHANGING TO RAIN
*  COLD AND DRY TOWARD THE END OF THE WEEK

OVERVIEW AND MODEL PREFERENCES...

ONE THING IS FOR CERTAIN...WITH LITTLE CHANGE IN THE NAO/AO AND
THE PNA EXPECTED TO REBOUND FROM NEGATIVE VALUES BACK TOWARD A
MORE NEUTRAL SOLUTION...THE COLD AIR AND LONGWAVE TROF LOOK TO
REMAIN THROUGH THE LONG TERM FORECAST. THE ONLY CAVEAT WILL BE IN
THE LOW LVLS ON WED...WHEN A ROBUST SW LLJ WILL ALLOW LOW-MID LVL
TEMPS TO WARM CLOSER TO ABOVE CLIMATOLOGICAL NORMALS. HOWEVER...
THE COLD AIR INITIALLY IN PLACE WILL LEAD TO P-TYPE ISSUES FOR THE
MID WEEK SYSTEM. ECMWF DETERMINISTIC REMAINS THE MOST ROBUST OF
THE OPERATIONAL MODELS...WITH HIGHER AMPLIFICATION IN THE FLOW
PATTERN THAN THE GFS AND UKMET. IT STARTS MUCH COLDER...BUT ENDS
MUCH WARMER. HOWEVER...DO NOTE THAT SOME OF THE GEFS AND ECENS
ENSEMBLES AGREE WITH THE ECMWF. THEREFORE...WILL BE USING THE
ENSEMBLE BLEND AS A BASELINE AS THIS TAKES INTO ACCOUNT BOTH THE
MORE PROGRESSIVE /AND ULTIMATELY LESS ROBUST WITH THE THERMAL
DIFFERENCES/ AND THE POTENTIAL FOR A MORE DYNAMIC SYSTEM. WILL USE
THIS BLEND THROUGH THE REMAINDER OF THE FORECAST AS WELL.

DETAILS...

MONDAY...

MORNING SNOWS COME TO AN END EARLY ACROSS E MA...AND FLURRIES
DISSIPATE THROUGH THE BERKSHIRES AND LITCHFIELD HILLS AS DRY NW
FLOW MOVES IN. BLUSTERY CONDITIONS EXPECTED...AND EVEN THROUGH
HIGHS WILL STILL BE MAKING IT INTO THE LOW-UPPER 30S...NW WINDS
WITH GUSTS 25-35 MPH AT TIMES WILL YIELD WIND CHILLS STRUGGLING
INTO THE LOW 20S.

MONDAY NIGHT INTO TUESDAY...

HIGH PRES WILL MOVE ACROSS THE REGION. DRY CONDITIONS DOMINATE
ALTHOUGH WITH TEMPS REMAINING BELOW NORMAL.

TUESDAY NIGHT INTO THURSDAY...

MODEL CONSENSUS IS NOW GENERALLY IN AGREEMENT THAT BOTH THE NRN
AND SRN STREAMS PHASE IN SOME FASHION ACROSS THE CENTRAL CONUS
WITH THE FORMATION OF LOW PRES WHICH IS EXPECTED TO SLIDE ACROSS
SRN CANADA. WARM FRONT WILL APPROACH...BUT GIVEN DEEP SNOWPACK THE
LOW LVL FRONT MAY ACTUAL STALL NEAR THE S COAST AS THE LOW MOVES
OVER AS THE UPPER WARM FRONT SLIDES INTO CENTRAL NEW ENGLAND. THIS
PRESENTS A GOOD OVERRUNNING SITUATION WITH STRONG 50-60 KT H92 LLJ
OUT OF THE SW. GIVEN THAT THIS SYSTEM IS ASSOCIATED WITH THE SRN
STREAM...IT ALSO CARRIES WITH IT A FAIR AMOUNT OF MOISTURE AS
PWATS LOOK TO REACH 2-3 STD DEVIATIONS ABOVE NORMAL

SO ALL IN ALL..PLENTY OF INGREDIENTS FOR HEAVY PRECIP ACROSS THE
AREA. THE QUESTION WILL BE TYPE...ALL GUIDANCE BEGIN COLD ENOUGH
FOR SNOW AT ONSET TUE NIGHT INTO EARLY WED. ECMWF WOULD SUGGEST
MUCH MORE AND BETTER LIFT IN THE SNOW GROWTH REGION...SO THERE IS
THAT TO CONSIDER. IN ANY CASE...WILL NEED TO AT LEAST WATCH FOR
POTENTIAL WARNING LEVEL SNOWFALL BEFORE THE WARM AIR BEGINS TO
BUILD IN FROM S TO N THROUGH THE DAY ON WED. EVEN THOUGH THE ECMWF
STARTS THE COLDEST...IT ENDS AS THE WARMEST SOLUTION...BRINGING
THE H92 +8C LINE ALL THE WAY INTO CENTRAL MA. SO WE DO EXPECT A
GRADUAL SHIFT TO A WINTRY MIX INCLUDING SLEET AND FREEZING RAIN
FOR A TIME GIVEN THE DEEP SNOWPACK ACROSS THE REGION. SOME AREAS
OF WRN MA...AND THE HILLS OF NRN CT MAY ACTUALLY STAY AS A MIX OF
SLEET FREEZING RAIN AND EVEN MAYBE SOME SNOW GIVEN THAT THE SFC
WARM FRONT MAY STALL. WILL HAVE TO WATCH FOR ICY CONDITIONS WITH
AS MUCH AS A QUARTER INCH OF ICE NOT OUT OF THE QUESTION WHERE IT
DOESN/T SWITCH TO RAIN WITH MELTING /BEST CHANCE OF RAIN/MELT IS
IN RI/CT AND PORTIONS OF MASS E OF I-495 AND S OF THE MASS PIKE/.
HEAVY RAIN A THREAT TOO GIVEN UPPER LVL INSTABILITY AND ROBUST
LLJ...SO WHERE MELTING AND HEAVY RAIN ARE OBSERVED...POOR DRAINAGE
FLOODING IS A POSSIBILITY WHERE SNOW CLOGS AREA DRAINS.

THIS HEAVY MIXED PRECIP EVENT COULD LINGER INTO THU...THE MORE
AMPLIFIED ECMWF AND SEVERAL ECENS/GEFS MEMBERS SUGGEST THAT THE
LEFTOVER COLD FRONT STALLS WITH YET ANOTHER WEAK WAVE OF LOW PRES
MOVING THROUGH THU. OTHER SOLUTIONS ARE MORE PROGRESSIVE AND HAVE
LESS QPF /SNOW POTENTIALLY/ ON THE BACK END. HOWEVER...BY THU
AFTERNOON/EVENING...CONDITIONS SHOULD BE IMPROVING /ALTHOUGH WITH
RAPID TEMPERATURE DROP/.

LATE NEXT WEEK...

EVEN THOUGH THERE IS UNCERTAINTY WITH HOW AMPLIFIED THE PATTERN
IS BY LATE WEEK. IT APPEARS A PERIOD OF DRY BUT COLD WX IS LIKELY
AS ARCTIC AIR ONCE AGAIN SHIFTS IN BEHIND THE EXITING MID WEEK
SYSTEM.

&&

.AVIATION /20Z SATURDAY THROUGH THURSDAY/...

FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /THROUGH MONDAY MORNING/...

21Z UPDATE...

TONIGHT THROUGH SUNDAY MIDDAY...HIGH CONFIDENCE.

VFR. LOWERING AND THICKENING CLOUDS SUNDAY MORNING INTO MIDDAY.
LOW-END VFR TO W-TERMINALS BY END OF PERIOD.

SUNDAY AFTERNOON INTO MONDAY MORNING...MODERATE CONFIDENCE.

SNOW OVERSPREADS THE REGION W-E. CIGS/VSBYS DETERIORATE TO MVFR-
IFR BY EARLY EVENING...WIDESPREAD IFR-LIFR SUNDAY NIGHT. SN TO MIX
WITH OR CHANGE TO FZRA ACROSS OFFSHORE ISLAND TERMINALS OVERNIGHT.
PRECIP ENDS W-E TOWARD DAYBREAK MONDAY....CONDITIONS IMPROVE.

KBOS TAF...MODERATE CONFIDENCE. TRENDS CERTAIN BUT NOT SO MUCH THE
ACTUAL TIMING OF IMPACTS.

KBDL TAF...MODERATE CONFIDENCE. TRENDS CERTAIN BUT NOT SO MUCH
THE ACTUAL TIMING OF IMPACTS.

OUTLOOK...MONDAY THROUGH WEDNESDAY...

MONDAY...HIGH CONFIDENCE.

CONDITIONS IMPROVE EARLY FROM IFR/MVFR IN SNOWS AND LOW CIGS...
WITH VFR EXPECTED EVERYWHERE BY AFTERNOON. NW WINDS IN THE
AFTERNOON WITH GUSTS 25-30 KT.

MON NIGHT INTO TUE...HIGH CONFIDENCE.

MAINLY VFR. GRADUALLY LOWERING CIGS ON TUE.

TUE NIGHT INTO WED...MODERATE CONFIDENCE.

MIXED WINTRY PRECIP LIKELY STARTS AS ALL SNOW...TRANSITIONS TO A
MIX OF SLEET AND FREEZING RAIN...THEN TO ALL RAIN DURING THE DAY
ON WED. SOME SNOW AND ICE ACCUMULATIONS ARE LIKELY WITH IFR OR
POTENTIALLY EVEN LIFR CONDITIONS AT TIMES.

&&

.MARINE...

FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /THROUGH MONDAY MORNING/...HIGH CONFIDENCE.

HIGH PRESSURE NEARBY WILL KEEP WINDS/SEAS WELL BELOW SMALL CRAFT
ADVISORY THRESHOLDS INTO SUNDAY MORNING. A WEAK WAVE OF LOW
PRESSURE MOVES ACROSS THE WATERS LATE SUNDAY INTO SUNDAY NIGHT...
BUT WEAK PRESSURE GRADIENT SHOULD KEEP WINDS/SEAS BELOW SMALL
CRAFT THRESHOLDS.

OUTLOOK...MONDAY THROUGH WEDNESDAY...

MONDAY INTO MONDAY NIGHT...HIGH CONFIDENCE.

SW WINDS SHIFT TO THE NW DURING THE DAYLIGHT HOURS AS A COLD
FRONT SWEEPS ACROSS THE WATERS. ONCE WINDS SHIFT NW IN THE
AFTERNOON EXPECT GALE FORCE GUSTS 35-40KT. COLDER AIR TUE NIGHT
COULD LEAD TO LIGHT FREEZING SPRAY.

TUESDAY...MODERATE CONFIDENCE.

WINDS GRADUALLY DIMINISH OUT OF THE W-NW BUT SEAS ARE LIKELY TO
REMAIN ELEVATED 5-8FT ON THE OCEAN WATERS. SMALL CRAFT ADVISORIES
WILL LIKELY BE NEEDED.

TUESDAY NIGHT INTO WEDNESDAY...MODERATE CONFIDENCE.

SNOW CHANGES TO RAIN TUE NIGHT WITH LOW VSBYS OVER THE WATERS.
WINDS OUT OF THE S MAINLY AROUND 25-30 KT AT MOST. SEAS BUILD
12-15 FT BY DAYTIME ON WED ON SE OCEAN WATERS. SMALL CRAFT
ADVISORIES WILL LIKELY BE NEEDED.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...

CT...WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY
     MORNING FOR CTZ002>004.
MA...WINTER WEATHER ADVISORY FROM NOON SUNDAY TO 7 AM EST MONDAY
     FOR MAZ002>008-010-014-023-024-026.
     WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY
     MORNING FOR MAZ009-011>013-015>022.
RI...WINTER WEATHER ADVISORY FROM NOON SUNDAY TO 7 AM EST MONDAY
     FOR RIZ008.
     WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY
     MORNING FOR RIZ001>007.
MARINE...NONE.

&&

$$

SYNOPSIS...DOODY/SIPPRELL
NEAR TERM...SIPPRELL
SHORT TERM...SIPPRELL
LONG TERM...DOODY
AVIATION...DOODY/SIPPRELL
MARINE...DOODY/SIPPRELL




000
FXUS61 KBOX 282032
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
332 PM EST SAT FEB 28 2015

.SYNOPSIS...

A FAST MOVING LOW PRESSURE SYSTEM WILL BRING ACCUMULATING SNOW TO
THE REGION LATE SUNDAY INTO SUNDAY NIGHT...WITH THE HIGHEST AMOUNTS
EXPECTED SOUTH OF THE MASSACHUSETTS TURNPIKE AND AWAY FROM THE
IMMEDIATE SOUTH COAST. ANOTHER STORM IS LIKELY TUESDAY NIGHT INTO
WEDNESDAY...WITH SNOW AND MIXED PRECIPITATION LIKELY CHANGING TO
RAIN. COLD AND DRY CONDITIONS RETURN FOR THE END OF NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...

INTO THIS EVENING...

HIGH PRESSURE PUSHING E INTO THE REGION. TEMPERATURES EXPECTED TO
QUICKLY DROP WITH MOSTLY CLEAR CONDITIONS AND LIGHT WINDS.

TONIGHT...

COLD. CONDITIONS WILL BE JUST RIGHT TO ALLOW FOR GOOD RADIATIONAL
COOLING...ESPECIALLY TO THE E WHERE THE IMPACT OF INCREASING MID- TO
HIGH-CLOUDS LATE IN THE PERIOD WILL BE LESS. LOOKING AT SUB-ZERO
LOWS FOR LOW-LYING AREAS WHERE COLD-AIR DRAINAGE EFFECTS OFF THE
HIGH TERRAIN ARE MAXIMIZED. HIGH-TERRAIN SHOULD REMAIN AT OR ABOVE
ZERO.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...

*/ SUNDAY MORNING INTO MIDDAY...

QUIET WEATHER. CLOUDS THICKENING AS WINDS INCREASE OUT OF THE S.
WILL SEE TEMPERATURES GRADUALLY MODERATE INTO THE MID- TO UPPER-20S.

*/ SUNDAY AFTERNOON INTO EARLY MONDAY MORNING...

1) HIGHLIGHTS...

 - SNOW SUNDAY AFTERNOON INTO MONDAY MORNING
 - GREATEST INTENSITY SUNDAY EVENING AND OVERNIGHT
 - 6+ INCH SNOWFALLS EXPECTED BUT EXACTLY WHERE REMAINS UNCERTAIN
 - ANNOYINGLY...FORECAST GUIDANCE CONTINUES TO WOBBLE

1) OVERVIEW...

BROAD ISENTROPIC OVER-RUNNING EVENT OF GULF MOISTURE ALONG THE 275-
295K SURFACES AMPLIFIED BY A N-STREAM IMPULSE DURING THE TIMEFRAME
POSSIBLY INVOKING AN AREA OF LOW PRESSURE THAT SKIRTS ALONG THE S-
COAST SUBSEQUENTLY ENHANCING LOW-LEVEL WIND PROFILE. LIGHT-MODERATE
SNOWFALL IS ANTICIPATED WITH LOCALLY HEAVIER AMOUNTS. THE INTENSE
PORTION OF SNOWFALL IS EXPECTED SUNDAY EVENING AND OVERNIGHT ENDING
EARLY MONDAY MORNING.

MODEL PREFERENCE GIVEN TO THE ECMWF/GFS/REGIONAL CANADIAN WHICH WILL
SERVE AS THE CONSENSUS OF GUIDANCE FOR THIS DISCUSSION. THE 28.12Z
NAM WAS CONSIDERED AN OUTLIER WITH ITS AGGRESSIVE-MODE AND SECONDARY
LOW DEVELOPMENT JUST OFFSHORE.

2) PRECIPITATION-TYPE...

EVALUATING THERMAL FIELDS...BLEND OF FORECAST CONSENSUS PUTS THE
-2C H925 ISOTHERM W-E ACROSS S-TIER OF CT/RI AND ACROSS SE MA WITH
THE 0C H85 ISOTHERM JUST S OF LONG-ISLAND AND NANTUCKET COASTLINES.
THE CONSENSUS OF 1000-850 MB CRITICAL THICKNESSES LAYS RIGHT ALONG
THE IMMEDIATE S-COAST OF LONG-ISLAND AND CAPE COD.

AN ALL SNOW-EVENT WHEN CONSIDERING DYNAMIC-COOLING/WETBULBING OF THE
LOW-LEVELS AHEAD OF THE EVENT. THERE IS PERHAPS A CHANCE OF A BRIEF
MIX-OVER TO RAIN/FREEZING RAIN ACROSS THE CAPE AND ISLANDS AS S-FLOW
AT THE SURFACE IS POSSIBLY ABLE TO NUDGE ABOVE-FREEZING TEMPERATURES
N. YET AS WE ARE IN A FROZEN TUNDRA...WITH ANY RAIN IT WOULD LIKELY
FREEZE ON SURFACES WHICH ARE QUITE COLD. THUS FREEZING RAIN PREVAILS
OVER RAIN IN THE FORECAST.

3) SNOWFALL...

FORECAST CONSENSUS OF A 0.3-0.6 N-S PRECIPITATION EVENT WITH A N-S
SNOW-TO-LIQUID RATIO GRADIENT RANGING FROM 15:1 TO 10:1 YIELDS HIGH-
END SNOW ADVISORY CRITERIA WITH SNOWFALL AMOUNTS RANGING ON AVERAGE
AROUND 3-6 INCHES. AREAS OF 6+ INCHES ARE EXPECTED...ESPECIALLY FROM
CENTRAL-CT E INTO SE-MA /INCLUDING THE UPPER-CAPE/. A CHALLENGE AND
A LOT OF UNCERTAINTY WITH RESPECT TO HEADLINES AND DECISION-MAKING.

EVALUATING LOW-LEVEL THERMAL PROFILES TOWARDS SNOW-TO-LIQUID RATIOS
DERIVED VIA A COBB-TECHNIQUE...WITH THE GREATEST LIFT OCCURRING
JUST BENEATH OR WITHIN THE DENDRITIC-GROWTH ZONE BASED ON A
CONSENSUS OF BUFKIT GFS PROFILES...ESPECIALLY IN HEAVIER- PRECIP
AREAS...BELIEVE THE SNOW WILL RANGE SOMEWHERE BETWEEN A WET AND
FLUFFY SNOW. SNOW PROPERTIES FROM FLUFFY TO WET LIKELY SIMILAR TO
THE N-S GRADIENT AS OUTLINED ABOVE.

4) HEADLINES...

HATE A WOBBLING FORECAST WHICH IS TYPICAL WITH SUCH SMALL EVENTS.
UNCERTAINTY DERIVES FROM LOW-LEVEL THERMAL PROFILES AND PRECIP
AMOUNTS. SURELY EXPECTING SNOW...BUT WITH ANY SHIFT N-S OF COLDER
AIR AND/OR PRECIPITATION AMOUNTS RESULTS IN AREAS SHIFTING FROM
ADVISORY TO WARNING...OR VICE VERSA. ENOUGH TO JUST PULL YOUR HAIR
OUT. THEN THERE IS THE TIMING OF THE SYSTEM THAT HAS SPED UP
SLIGHTLY. A SHORTER RESIDENCE TIME OF COURSE WOULD YIELD LESSER
SNOWFALL AMOUNTS. QUITE A CHALLENGING FORECAST RIGHT ON THE CUSP
OF HEADLINE THRESHOLDS.

THE EVENT DOES TAKE PLACE MAINLY FROM SUNDAY EVENING INTO THE EARLY
MORNING HOURS ON MONDAY DURING WHICH TIME THERE IS NOT MUCH TRAFFIC
ON THE ROAD. IS THIS A HIGH IMPACT EVENT THAT WARRANTS WARNINGS? A
QUESTION TO STRUGGLE WITH AS WARNINGS ARE NECESSARY WHEN WE ARE
CONFIDENT IN MEETING OR EXCEEDING 6+ INCH CRITERIA. YET THE QUESTION
IN FRONT OF US IS WHERE WILL THE HIGHER AMOUNTS OF SNOW FOCUS? HAVE
TO MAKE SOME SORT OF CALL...THE NEEDS OF THE MANY OUTWEIGH THE NEEDS
OF THE FEW.

ADVISORIES POSTED WHERE THERE IS HIGH CONFIDENCE OF SNOW BUT LIKELY
TO REMAIN BELOW THE 6-INCH THRESHOLD FOR WARNING. WATCHES CONTINUE
AND HAVE BEEN EXTENDED TO THE S-COAST TO COVER FOR THE UNCERTAINTY
OF THE AREA EITHER FALLING WITHIN OR IN EXCESS OF ADVISORY-LEVEL
SNOWS. AGAIN...6+ INCH AMOUNTS ARE ANTICIPATED BUT EXACTLY WHERE IS
UNCERTAIN.

5) CLOSING NOTES...

SOME CONCERN FOR THE EARLY MONDAY MORNING COMMUTE FOR E/SE MA AND
RI. WHILE MOST OF THE SNOW IS EXPECTED TO BE IMMEDIATELY OFFSHORE
WITH SUNRISE MONDAY...COMMUTERS COULD ENCOUNTER SLICK AND SLIPPERY
ROAD CONDITIONS. SNOW COULD POSSIBLY LINGER OVER SE MA SO THERE IS
THE POTENTIAL FOR REDUCED VISIBILITIES.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...

HIGHLIGHTS...

*  CONDITIONS IMPROVE MONDAY
*  ANOTHER STORM POSSIBLE TUE NIGHT INTO WED...WITH SNOW OR
   MIXED PRECIP LIKELY CHANGING TO RAIN
*  COLD AND DRY TOWARD THE END OF THE WEEK

OVERVIEW AND MODEL PREFERENCES...

ONE THING IS FOR CERTAIN...WITH LITTLE CHANGE IN THE NAO/AO AND
THE PNA EXPECTED TO REBOUND FROM NEGATIVE VALUES BACK TOWARD A
MORE NEUTRAL SOLUTION...THE COLD AIR AND LONGWAVE TROF LOOK TO
REMAIN THROUGH THE LONG TERM FORECAST. THE ONLY CAVEAT WILL BE IN
THE LOW LVLS ON WED...WHEN A ROBUST SW LLJ WILL ALLOW LOW-MID LVL
TEMPS TO WARM CLOSER TO ABOVE CLIMATOLOGICAL NORMALS. HOWEVER...
THE COLD AIR INITIALLY IN PLACE WILL LEAD TO P-TYPE ISSUES FOR THE
MID WEEK SYSTEM. ECMWF DETERMINISTIC REMAINS THE MOST ROBUST OF
THE OPERATIONAL MODELS...WITH HIGHER AMPLIFICATION IN THE FLOW
PATTERN THAN THE GFS AND UKMET. IT STARTS MUCH COLDER...BUT ENDS
MUCH WARMER. HOWEVER...DO NOTE THAT SOME OF THE GEFS AND ECENS
ENSEMBLES AGREE WITH THE ECMWF. THEREFORE...WILL BE USING THE
ENSEMBLE BLEND AS A BASELINE AS THIS TAKES INTO ACCOUNT BOTH THE
MORE PROGRESSIVE /AND ULTIMATELY LESS ROBUST WITH THE THERMAL
DIFFERENCES/ AND THE POTENTIAL FOR A MORE DYNAMIC SYSTEM. WILL USE
THIS BLEND THROUGH THE REMAINDER OF THE FORECAST AS WELL.

DETAILS...

MONDAY...

MORNING SNOWS COME TO AN END EARLY ACROSS E MA...AND FLURRIES
DISSIPATE THROUGH THE BERKSHIRES AND LITCHFIELD HILLS AS DRY NW
FLOW MOVES IN. BLUSTERY CONDITIONS EXPECTED...AND EVEN THROUGH
HIGHS WILL STILL BE MAKING IT INTO THE LOW-UPPER 30S...NW WINDS
WITH GUSTS 25-35 MPH AT TIMES WILL YIELD WIND CHILLS STRUGGLING
INTO THE LOW 20S.

MONDAY NIGHT INTO TUESDAY...

HIGH PRES WILL MOVE ACROSS THE REGION. DRY CONDITIONS DOMINATE
ALTHOUGH WITH TEMPS REMAINING BELOW NORMAL.

TUESDAY NIGHT INTO THURSDAY...

MODEL CONSENSUS IS NOW GENERALLY IN AGREEMENT THAT BOTH THE NRN
AND SRN STREAMS PHASE IN SOME FASHION ACROSS THE CENTRAL CONUS
WITH THE FORMATION OF LOW PRES WHICH IS EXPECTED TO SLIDE ACROSS
SRN CANADA. WARM FRONT WILL APPROACH...BUT GIVEN DEEP SNOWPACK THE
LOW LVL FRONT MAY ACTUAL STALL NEAR THE S COAST AS THE LOW MOVES
OVER AS THE UPPER WARM FRONT SLIDES INTO CENTRAL NEW ENGLAND. THIS
PRESENTS A GOOD OVERRUNNING SITUATION WITH STRONG 50-60 KT H92 LLJ
OUT OF THE SW. GIVEN THAT THIS SYSTEM IS ASSOCIATED WITH THE SRN
STREAM...IT ALSO CARRIES WITH IT A FAIR AMOUNT OF MOISTURE AS
PWATS LOOK TO REACH 2-3 STD DEVIATIONS ABOVE NORMAL

SO ALL IN ALL..PLENTY OF INGREDIENTS FOR HEAVY PRECIP ACROSS THE
AREA. THE QUESTION WILL BE TYPE...ALL GUIDANCE BEGIN COLD ENOUGH
FOR SNOW AT ONSET TUE NIGHT INTO EARLY WED. ECMWF WOULD SUGGEST
MUCH MORE AND BETTER LIFT IN THE SNOW GROWTH REGION...SO THERE IS
THAT TO CONSIDER. IN ANY CASE...WILL NEED TO AT LEAST WATCH FOR
POTENTIAL WARNING LEVEL SNOWFALL BEFORE THE WARM AIR BEGINS TO
BUILD IN FROM S TO N THROUGH THE DAY ON WED. EVEN THOUGH THE ECMWF
STARTS THE COLDEST...IT ENDS AS THE WARMEST SOLUTION...BRINGING
THE H92 +8C LINE ALL THE WAY INTO CENTRAL MA. SO WE DO EXPECT A
GRADUAL SHIFT TO A WINTRY MIX INCLUDING SLEET AND FREEZING RAIN
FOR A TIME GIVEN THE DEEP SNOWPACK ACROSS THE REGION. SOME AREAS
OF WRN MA...AND THE HILLS OF NRN CT MAY ACTUALLY STAY AS A MIX OF
SLEET FREEZING RAIN AND EVEN MAYBE SOME SNOW GIVEN THAT THE SFC
WARM FRONT MAY STALL. WILL HAVE TO WATCH FOR ICY CONDITIONS WITH
AS MUCH AS A QUARTER INCH OF ICE NOT OUT OF THE QUESTION WHERE IT
DOESN/T SWITCH TO RAIN WITH MELTING /BEST CHANCE OF RAIN/MELT IS
IN RI/CT AND PORTIONS OF MASS E OF I-495 AND S OF THE MASS PIKE/.
HEAVY RAIN A THREAT TOO GIVEN UPPER LVL INSTABILITY AND ROBUST
LLJ...SO WHERE MELTING AND HEAVY RAIN ARE OBSERVED...POOR DRAINAGE
FLOODING IS A POSSIBILITY WHERE SNOW CLOGS AREA DRAINS.

THIS HEAVY MIXED PRECIP EVENT COULD LINGER INTO THU...THE MORE
AMPLIFIED ECMWF AND SEVERAL ECENS/GEFS MEMBERS SUGGEST THAT THE
LEFTOVER COLD FRONT STALLS WITH YET ANOTHER WEAK WAVE OF LOW PRES
MOVING THROUGH THU. OTHER SOLUTIONS ARE MORE PROGRESSIVE AND HAVE
LESS QPF /SNOW POTENTIALLY/ ON THE BACK END. HOWEVER...BY THU
AFTERNOON/EVENING...CONDITIONS SHOULD BE IMPROVING /ALTHOUGH WITH
RAPID TEMPERATURE DROP/.

LATE NEXT WEEK...

EVEN THOUGH THERE IS UNCERTAINTY WITH HOW AMPLIFIED THE PATTERN
IS BY LATE WEEK. IT APPEARS A PERIOD OF DRY BUT COLD WX IS LIKELY
AS ARCTIC AIR ONCE AGAIN SHIFTS IN BEHIND THE EXITING MID WEEK
SYSTEM.

&&

.AVIATION /20Z SATURDAY THROUGH THURSDAY/...

FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /THROUGH MONDAY MORNING/...

21Z UPDATE...

TONIGHT THROUGH SUNDAY MIDDAY...HIGH CONFIDENCE.

VFR. LOWERING AND THICKENING CLOUDS SUNDAY MORNING INTO MIDDAY.
LOW-END VFR TO W-TERMINALS BY END OF PERIOD.

SUNDAY AFTERNOON INTO MONDAY MORNING...MODERATE CONFIDENCE.

SNOW OVERSPREADS THE REGION W-E. CIGS/VSBYS DETERIORATE TO MVFR-
IFR BY EARLY EVENING...WIDESPREAD IFR-LIFR SUNDAY NIGHT. SN TO MIX
WITH OR CHANGE TO FZRA ACROSS OFFSHORE ISLAND TERMINALS OVERNIGHT.
PRECIP ENDS W-E TOWARD DAYBREAK MONDAY....CONDITIONS IMPROVE.

KBOS TAF...MODERATE CONFIDENCE. TRENDS CERTAIN BUT NOT SO MUCH THE
ACTUAL TIMING OF IMPACTS.

KBDL TAF...MODERATE CONFIDENCE. TRENDS CERTAIN BUT NOT SO MUCH
THE ACTUAL TIMING OF IMPACTS.

OUTLOOK...MONDAY THROUGH WEDNESDAY...

MONDAY...HIGH CONFIDENCE.

CONDITIONS IMPROVE EARLY FROM IFR/MVFR IN SNOWS AND LOW CIGS...
WITH VFR EXPECTED EVERYWHERE BY AFTERNOON. NW WINDS IN THE
AFTERNOON WITH GUSTS 25-30 KT.

MON NIGHT INTO TUE...HIGH CONFIDENCE.

MAINLY VFR. GRADUALLY LOWERING CIGS ON TUE.

TUE NIGHT INTO WED...MODERATE CONFIDENCE.

MIXED WINTRY PRECIP LIKELY STARTS AS ALL SNOW...TRANSITIONS TO A
MIX OF SLEET AND FREEZING RAIN...THEN TO ALL RAIN DURING THE DAY
ON WED. SOME SNOW AND ICE ACCUMULATIONS ARE LIKELY WITH IFR OR
POTENTIALLY EVEN LIFR CONDITIONS AT TIMES.

&&

.MARINE...

FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /THROUGH MONDAY MORNING/...HIGH CONFIDENCE.

HIGH PRESSURE NEARBY WILL KEEP WINDS/SEAS WELL BELOW SMALL CRAFT
ADVISORY THRESHOLDS INTO SUNDAY MORNING. A WEAK WAVE OF LOW
PRESSURE MOVES ACROSS THE WATERS LATE SUNDAY INTO SUNDAY NIGHT...
BUT WEAK PRESSURE GRADIENT SHOULD KEEP WINDS/SEAS BELOW SMALL
CRAFT THRESHOLDS.

OUTLOOK...MONDAY THROUGH WEDNESDAY...

MONDAY INTO MONDAY NIGHT...HIGH CONFIDENCE.

SW WINDS SHIFT TO THE NW DURING THE DAYLIGHT HOURS AS A COLD
FRONT SWEEPS ACROSS THE WATERS. ONCE WINDS SHIFT NW IN THE
AFTERNOON EXPECT GALE FORCE GUSTS 35-40KT. COLDER AIR TUE NIGHT
COULD LEAD TO LIGHT FREEZING SPRAY.

TUESDAY...MODERATE CONFIDENCE.

WINDS GRADUALLY DIMINISH OUT OF THE W-NW BUT SEAS ARE LIKELY TO
REMAIN ELEVATED 5-8FT ON THE OCEAN WATERS. SMALL CRAFT ADVISORIES
WILL LIKELY BE NEEDED.

TUESDAY NIGHT INTO WEDNESDAY...MODERATE CONFIDENCE.

SNOW CHANGES TO RAIN TUE NIGHT WITH LOW VSBYS OVER THE WATERS.
WINDS OUT OF THE S MAINLY AROUND 25-30 KT AT MOST. SEAS BUILD
12-15 FT BY DAYTIME ON WED ON SE OCEAN WATERS. SMALL CRAFT
ADVISORIES WILL LIKELY BE NEEDED.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...

CT...WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY
     MORNING FOR CTZ002>004.
MA...WINTER WEATHER ADVISORY FROM NOON SUNDAY TO 7 AM EST MONDAY
     FOR MAZ002>008-010-014-023-024-026.
     WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY
     MORNING FOR MAZ009-011>013-015>022.
RI...WINTER WEATHER ADVISORY FROM NOON SUNDAY TO 7 AM EST MONDAY
     FOR RIZ008.
     WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY
     MORNING FOR RIZ001>007.
MARINE...NONE.

&&

$$

SYNOPSIS...DOODY/SIPPRELL
NEAR TERM...SIPPRELL
SHORT TERM...SIPPRELL
LONG TERM...DOODY
AVIATION...DOODY/SIPPRELL
MARINE...DOODY/SIPPRELL



000
FXUS61 KBOX 282032
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
332 PM EST SAT FEB 28 2015

.SYNOPSIS...

A FAST MOVING LOW PRESSURE SYSTEM WILL BRING ACCUMULATING SNOW TO
THE REGION LATE SUNDAY INTO SUNDAY NIGHT...WITH THE HIGHEST AMOUNTS
EXPECTED SOUTH OF THE MASSACHUSETTS TURNPIKE AND AWAY FROM THE
IMMEDIATE SOUTH COAST. ANOTHER STORM IS LIKELY TUESDAY NIGHT INTO
WEDNESDAY...WITH SNOW AND MIXED PRECIPITATION LIKELY CHANGING TO
RAIN. COLD AND DRY CONDITIONS RETURN FOR THE END OF NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...

INTO THIS EVENING...

HIGH PRESSURE PUSHING E INTO THE REGION. TEMPERATURES EXPECTED TO
QUICKLY DROP WITH MOSTLY CLEAR CONDITIONS AND LIGHT WINDS.

TONIGHT...

COLD. CONDITIONS WILL BE JUST RIGHT TO ALLOW FOR GOOD RADIATIONAL
COOLING...ESPECIALLY TO THE E WHERE THE IMPACT OF INCREASING MID- TO
HIGH-CLOUDS LATE IN THE PERIOD WILL BE LESS. LOOKING AT SUB-ZERO
LOWS FOR LOW-LYING AREAS WHERE COLD-AIR DRAINAGE EFFECTS OFF THE
HIGH TERRAIN ARE MAXIMIZED. HIGH-TERRAIN SHOULD REMAIN AT OR ABOVE
ZERO.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...

*/ SUNDAY MORNING INTO MIDDAY...

QUIET WEATHER. CLOUDS THICKENING AS WINDS INCREASE OUT OF THE S.
WILL SEE TEMPERATURES GRADUALLY MODERATE INTO THE MID- TO UPPER-20S.

*/ SUNDAY AFTERNOON INTO EARLY MONDAY MORNING...

1) HIGHLIGHTS...

 - SNOW SUNDAY AFTERNOON INTO MONDAY MORNING
 - GREATEST INTENSITY SUNDAY EVENING AND OVERNIGHT
 - 6+ INCH SNOWFALLS EXPECTED BUT EXACTLY WHERE REMAINS UNCERTAIN
 - ANNOYINGLY...FORECAST GUIDANCE CONTINUES TO WOBBLE

1) OVERVIEW...

BROAD ISENTROPIC OVER-RUNNING EVENT OF GULF MOISTURE ALONG THE 275-
295K SURFACES AMPLIFIED BY A N-STREAM IMPULSE DURING THE TIMEFRAME
POSSIBLY INVOKING AN AREA OF LOW PRESSURE THAT SKIRTS ALONG THE S-
COAST SUBSEQUENTLY ENHANCING LOW-LEVEL WIND PROFILE. LIGHT-MODERATE
SNOWFALL IS ANTICIPATED WITH LOCALLY HEAVIER AMOUNTS. THE INTENSE
PORTION OF SNOWFALL IS EXPECTED SUNDAY EVENING AND OVERNIGHT ENDING
EARLY MONDAY MORNING.

MODEL PREFERENCE GIVEN TO THE ECMWF/GFS/REGIONAL CANADIAN WHICH WILL
SERVE AS THE CONSENSUS OF GUIDANCE FOR THIS DISCUSSION. THE 28.12Z
NAM WAS CONSIDERED AN OUTLIER WITH ITS AGGRESSIVE-MODE AND SECONDARY
LOW DEVELOPMENT JUST OFFSHORE.

2) PRECIPITATION-TYPE...

EVALUATING THERMAL FIELDS...BLEND OF FORECAST CONSENSUS PUTS THE
-2C H925 ISOTHERM W-E ACROSS S-TIER OF CT/RI AND ACROSS SE MA WITH
THE 0C H85 ISOTHERM JUST S OF LONG-ISLAND AND NANTUCKET COASTLINES.
THE CONSENSUS OF 1000-850 MB CRITICAL THICKNESSES LAYS RIGHT ALONG
THE IMMEDIATE S-COAST OF LONG-ISLAND AND CAPE COD.

AN ALL SNOW-EVENT WHEN CONSIDERING DYNAMIC-COOLING/WETBULBING OF THE
LOW-LEVELS AHEAD OF THE EVENT. THERE IS PERHAPS A CHANCE OF A BRIEF
MIX-OVER TO RAIN/FREEZING RAIN ACROSS THE CAPE AND ISLANDS AS S-FLOW
AT THE SURFACE IS POSSIBLY ABLE TO NUDGE ABOVE-FREEZING TEMPERATURES
N. YET AS WE ARE IN A FROZEN TUNDRA...WITH ANY RAIN IT WOULD LIKELY
FREEZE ON SURFACES WHICH ARE QUITE COLD. THUS FREEZING RAIN PREVAILS
OVER RAIN IN THE FORECAST.

3) SNOWFALL...

FORECAST CONSENSUS OF A 0.3-0.6 N-S PRECIPITATION EVENT WITH A N-S
SNOW-TO-LIQUID RATIO GRADIENT RANGING FROM 15:1 TO 10:1 YIELDS HIGH-
END SNOW ADVISORY CRITERIA WITH SNOWFALL AMOUNTS RANGING ON AVERAGE
AROUND 3-6 INCHES. AREAS OF 6+ INCHES ARE EXPECTED...ESPECIALLY FROM
CENTRAL-CT E INTO SE-MA /INCLUDING THE UPPER-CAPE/. A CHALLENGE AND
A LOT OF UNCERTAINTY WITH RESPECT TO HEADLINES AND DECISION-MAKING.

EVALUATING LOW-LEVEL THERMAL PROFILES TOWARDS SNOW-TO-LIQUID RATIOS
DERIVED VIA A COBB-TECHNIQUE...WITH THE GREATEST LIFT OCCURRING
JUST BENEATH OR WITHIN THE DENDRITIC-GROWTH ZONE BASED ON A
CONSENSUS OF BUFKIT GFS PROFILES...ESPECIALLY IN HEAVIER- PRECIP
AREAS...BELIEVE THE SNOW WILL RANGE SOMEWHERE BETWEEN A WET AND
FLUFFY SNOW. SNOW PROPERTIES FROM FLUFFY TO WET LIKELY SIMILAR TO
THE N-S GRADIENT AS OUTLINED ABOVE.

4) HEADLINES...

HATE A WOBBLING FORECAST WHICH IS TYPICAL WITH SUCH SMALL EVENTS.
UNCERTAINTY DERIVES FROM LOW-LEVEL THERMAL PROFILES AND PRECIP
AMOUNTS. SURELY EXPECTING SNOW...BUT WITH ANY SHIFT N-S OF COLDER
AIR AND/OR PRECIPITATION AMOUNTS RESULTS IN AREAS SHIFTING FROM
ADVISORY TO WARNING...OR VICE VERSA. ENOUGH TO JUST PULL YOUR HAIR
OUT. THEN THERE IS THE TIMING OF THE SYSTEM THAT HAS SPED UP
SLIGHTLY. A SHORTER RESIDENCE TIME OF COURSE WOULD YIELD LESSER
SNOWFALL AMOUNTS. QUITE A CHALLENGING FORECAST RIGHT ON THE CUSP
OF HEADLINE THRESHOLDS.

THE EVENT DOES TAKE PLACE MAINLY FROM SUNDAY EVENING INTO THE EARLY
MORNING HOURS ON MONDAY DURING WHICH TIME THERE IS NOT MUCH TRAFFIC
ON THE ROAD. IS THIS A HIGH IMPACT EVENT THAT WARRANTS WARNINGS? A
QUESTION TO STRUGGLE WITH AS WARNINGS ARE NECESSARY WHEN WE ARE
CONFIDENT IN MEETING OR EXCEEDING 6+ INCH CRITERIA. YET THE QUESTION
IN FRONT OF US IS WHERE WILL THE HIGHER AMOUNTS OF SNOW FOCUS? HAVE
TO MAKE SOME SORT OF CALL...THE NEEDS OF THE MANY OUTWEIGH THE NEEDS
OF THE FEW.

ADVISORIES POSTED WHERE THERE IS HIGH CONFIDENCE OF SNOW BUT LIKELY
TO REMAIN BELOW THE 6-INCH THRESHOLD FOR WARNING. WATCHES CONTINUE
AND HAVE BEEN EXTENDED TO THE S-COAST TO COVER FOR THE UNCERTAINTY
OF THE AREA EITHER FALLING WITHIN OR IN EXCESS OF ADVISORY-LEVEL
SNOWS. AGAIN...6+ INCH AMOUNTS ARE ANTICIPATED BUT EXACTLY WHERE IS
UNCERTAIN.

5) CLOSING NOTES...

SOME CONCERN FOR THE EARLY MONDAY MORNING COMMUTE FOR E/SE MA AND
RI. WHILE MOST OF THE SNOW IS EXPECTED TO BE IMMEDIATELY OFFSHORE
WITH SUNRISE MONDAY...COMMUTERS COULD ENCOUNTER SLICK AND SLIPPERY
ROAD CONDITIONS. SNOW COULD POSSIBLY LINGER OVER SE MA SO THERE IS
THE POTENTIAL FOR REDUCED VISIBILITIES.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...

HIGHLIGHTS...

*  CONDITIONS IMPROVE MONDAY
*  ANOTHER STORM POSSIBLE TUE NIGHT INTO WED...WITH SNOW OR
   MIXED PRECIP LIKELY CHANGING TO RAIN
*  COLD AND DRY TOWARD THE END OF THE WEEK

OVERVIEW AND MODEL PREFERENCES...

ONE THING IS FOR CERTAIN...WITH LITTLE CHANGE IN THE NAO/AO AND
THE PNA EXPECTED TO REBOUND FROM NEGATIVE VALUES BACK TOWARD A
MORE NEUTRAL SOLUTION...THE COLD AIR AND LONGWAVE TROF LOOK TO
REMAIN THROUGH THE LONG TERM FORECAST. THE ONLY CAVEAT WILL BE IN
THE LOW LVLS ON WED...WHEN A ROBUST SW LLJ WILL ALLOW LOW-MID LVL
TEMPS TO WARM CLOSER TO ABOVE CLIMATOLOGICAL NORMALS. HOWEVER...
THE COLD AIR INITIALLY IN PLACE WILL LEAD TO P-TYPE ISSUES FOR THE
MID WEEK SYSTEM. ECMWF DETERMINISTIC REMAINS THE MOST ROBUST OF
THE OPERATIONAL MODELS...WITH HIGHER AMPLIFICATION IN THE FLOW
PATTERN THAN THE GFS AND UKMET. IT STARTS MUCH COLDER...BUT ENDS
MUCH WARMER. HOWEVER...DO NOTE THAT SOME OF THE GEFS AND ECENS
ENSEMBLES AGREE WITH THE ECMWF. THEREFORE...WILL BE USING THE
ENSEMBLE BLEND AS A BASELINE AS THIS TAKES INTO ACCOUNT BOTH THE
MORE PROGRESSIVE /AND ULTIMATELY LESS ROBUST WITH THE THERMAL
DIFFERENCES/ AND THE POTENTIAL FOR A MORE DYNAMIC SYSTEM. WILL USE
THIS BLEND THROUGH THE REMAINDER OF THE FORECAST AS WELL.

DETAILS...

MONDAY...

MORNING SNOWS COME TO AN END EARLY ACROSS E MA...AND FLURRIES
DISSIPATE THROUGH THE BERKSHIRES AND LITCHFIELD HILLS AS DRY NW
FLOW MOVES IN. BLUSTERY CONDITIONS EXPECTED...AND EVEN THROUGH
HIGHS WILL STILL BE MAKING IT INTO THE LOW-UPPER 30S...NW WINDS
WITH GUSTS 25-35 MPH AT TIMES WILL YIELD WIND CHILLS STRUGGLING
INTO THE LOW 20S.

MONDAY NIGHT INTO TUESDAY...

HIGH PRES WILL MOVE ACROSS THE REGION. DRY CONDITIONS DOMINATE
ALTHOUGH WITH TEMPS REMAINING BELOW NORMAL.

TUESDAY NIGHT INTO THURSDAY...

MODEL CONSENSUS IS NOW GENERALLY IN AGREEMENT THAT BOTH THE NRN
AND SRN STREAMS PHASE IN SOME FASHION ACROSS THE CENTRAL CONUS
WITH THE FORMATION OF LOW PRES WHICH IS EXPECTED TO SLIDE ACROSS
SRN CANADA. WARM FRONT WILL APPROACH...BUT GIVEN DEEP SNOWPACK THE
LOW LVL FRONT MAY ACTUAL STALL NEAR THE S COAST AS THE LOW MOVES
OVER AS THE UPPER WARM FRONT SLIDES INTO CENTRAL NEW ENGLAND. THIS
PRESENTS A GOOD OVERRUNNING SITUATION WITH STRONG 50-60 KT H92 LLJ
OUT OF THE SW. GIVEN THAT THIS SYSTEM IS ASSOCIATED WITH THE SRN
STREAM...IT ALSO CARRIES WITH IT A FAIR AMOUNT OF MOISTURE AS
PWATS LOOK TO REACH 2-3 STD DEVIATIONS ABOVE NORMAL

SO ALL IN ALL..PLENTY OF INGREDIENTS FOR HEAVY PRECIP ACROSS THE
AREA. THE QUESTION WILL BE TYPE...ALL GUIDANCE BEGIN COLD ENOUGH
FOR SNOW AT ONSET TUE NIGHT INTO EARLY WED. ECMWF WOULD SUGGEST
MUCH MORE AND BETTER LIFT IN THE SNOW GROWTH REGION...SO THERE IS
THAT TO CONSIDER. IN ANY CASE...WILL NEED TO AT LEAST WATCH FOR
POTENTIAL WARNING LEVEL SNOWFALL BEFORE THE WARM AIR BEGINS TO
BUILD IN FROM S TO N THROUGH THE DAY ON WED. EVEN THOUGH THE ECMWF
STARTS THE COLDEST...IT ENDS AS THE WARMEST SOLUTION...BRINGING
THE H92 +8C LINE ALL THE WAY INTO CENTRAL MA. SO WE DO EXPECT A
GRADUAL SHIFT TO A WINTRY MIX INCLUDING SLEET AND FREEZING RAIN
FOR A TIME GIVEN THE DEEP SNOWPACK ACROSS THE REGION. SOME AREAS
OF WRN MA...AND THE HILLS OF NRN CT MAY ACTUALLY STAY AS A MIX OF
SLEET FREEZING RAIN AND EVEN MAYBE SOME SNOW GIVEN THAT THE SFC
WARM FRONT MAY STALL. WILL HAVE TO WATCH FOR ICY CONDITIONS WITH
AS MUCH AS A QUARTER INCH OF ICE NOT OUT OF THE QUESTION WHERE IT
DOESN/T SWITCH TO RAIN WITH MELTING /BEST CHANCE OF RAIN/MELT IS
IN RI/CT AND PORTIONS OF MASS E OF I-495 AND S OF THE MASS PIKE/.
HEAVY RAIN A THREAT TOO GIVEN UPPER LVL INSTABILITY AND ROBUST
LLJ...SO WHERE MELTING AND HEAVY RAIN ARE OBSERVED...POOR DRAINAGE
FLOODING IS A POSSIBILITY WHERE SNOW CLOGS AREA DRAINS.

THIS HEAVY MIXED PRECIP EVENT COULD LINGER INTO THU...THE MORE
AMPLIFIED ECMWF AND SEVERAL ECENS/GEFS MEMBERS SUGGEST THAT THE
LEFTOVER COLD FRONT STALLS WITH YET ANOTHER WEAK WAVE OF LOW PRES
MOVING THROUGH THU. OTHER SOLUTIONS ARE MORE PROGRESSIVE AND HAVE
LESS QPF /SNOW POTENTIALLY/ ON THE BACK END. HOWEVER...BY THU
AFTERNOON/EVENING...CONDITIONS SHOULD BE IMPROVING /ALTHOUGH WITH
RAPID TEMPERATURE DROP/.

LATE NEXT WEEK...

EVEN THOUGH THERE IS UNCERTAINTY WITH HOW AMPLIFIED THE PATTERN
IS BY LATE WEEK. IT APPEARS A PERIOD OF DRY BUT COLD WX IS LIKELY
AS ARCTIC AIR ONCE AGAIN SHIFTS IN BEHIND THE EXITING MID WEEK
SYSTEM.

&&

.AVIATION /20Z SATURDAY THROUGH THURSDAY/...

FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /THROUGH MONDAY MORNING/...

21Z UPDATE...

TONIGHT THROUGH SUNDAY MIDDAY...HIGH CONFIDENCE.

VFR. LOWERING AND THICKENING CLOUDS SUNDAY MORNING INTO MIDDAY.
LOW-END VFR TO W-TERMINALS BY END OF PERIOD.

SUNDAY AFTERNOON INTO MONDAY MORNING...MODERATE CONFIDENCE.

SNOW OVERSPREADS THE REGION W-E. CIGS/VSBYS DETERIORATE TO MVFR-
IFR BY EARLY EVENING...WIDESPREAD IFR-LIFR SUNDAY NIGHT. SN TO MIX
WITH OR CHANGE TO FZRA ACROSS OFFSHORE ISLAND TERMINALS OVERNIGHT.
PRECIP ENDS W-E TOWARD DAYBREAK MONDAY....CONDITIONS IMPROVE.

KBOS TAF...MODERATE CONFIDENCE. TRENDS CERTAIN BUT NOT SO MUCH THE
ACTUAL TIMING OF IMPACTS.

KBDL TAF...MODERATE CONFIDENCE. TRENDS CERTAIN BUT NOT SO MUCH
THE ACTUAL TIMING OF IMPACTS.

OUTLOOK...MONDAY THROUGH WEDNESDAY...

MONDAY...HIGH CONFIDENCE.

CONDITIONS IMPROVE EARLY FROM IFR/MVFR IN SNOWS AND LOW CIGS...
WITH VFR EXPECTED EVERYWHERE BY AFTERNOON. NW WINDS IN THE
AFTERNOON WITH GUSTS 25-30 KT.

MON NIGHT INTO TUE...HIGH CONFIDENCE.

MAINLY VFR. GRADUALLY LOWERING CIGS ON TUE.

TUE NIGHT INTO WED...MODERATE CONFIDENCE.

MIXED WINTRY PRECIP LIKELY STARTS AS ALL SNOW...TRANSITIONS TO A
MIX OF SLEET AND FREEZING RAIN...THEN TO ALL RAIN DURING THE DAY
ON WED. SOME SNOW AND ICE ACCUMULATIONS ARE LIKELY WITH IFR OR
POTENTIALLY EVEN LIFR CONDITIONS AT TIMES.

&&

.MARINE...

FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /THROUGH MONDAY MORNING/...HIGH CONFIDENCE.

HIGH PRESSURE NEARBY WILL KEEP WINDS/SEAS WELL BELOW SMALL CRAFT
ADVISORY THRESHOLDS INTO SUNDAY MORNING. A WEAK WAVE OF LOW
PRESSURE MOVES ACROSS THE WATERS LATE SUNDAY INTO SUNDAY NIGHT...
BUT WEAK PRESSURE GRADIENT SHOULD KEEP WINDS/SEAS BELOW SMALL
CRAFT THRESHOLDS.

OUTLOOK...MONDAY THROUGH WEDNESDAY...

MONDAY INTO MONDAY NIGHT...HIGH CONFIDENCE.

SW WINDS SHIFT TO THE NW DURING THE DAYLIGHT HOURS AS A COLD
FRONT SWEEPS ACROSS THE WATERS. ONCE WINDS SHIFT NW IN THE
AFTERNOON EXPECT GALE FORCE GUSTS 35-40KT. COLDER AIR TUE NIGHT
COULD LEAD TO LIGHT FREEZING SPRAY.

TUESDAY...MODERATE CONFIDENCE.

WINDS GRADUALLY DIMINISH OUT OF THE W-NW BUT SEAS ARE LIKELY TO
REMAIN ELEVATED 5-8FT ON THE OCEAN WATERS. SMALL CRAFT ADVISORIES
WILL LIKELY BE NEEDED.

TUESDAY NIGHT INTO WEDNESDAY...MODERATE CONFIDENCE.

SNOW CHANGES TO RAIN TUE NIGHT WITH LOW VSBYS OVER THE WATERS.
WINDS OUT OF THE S MAINLY AROUND 25-30 KT AT MOST. SEAS BUILD
12-15 FT BY DAYTIME ON WED ON SE OCEAN WATERS. SMALL CRAFT
ADVISORIES WILL LIKELY BE NEEDED.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...

CT...WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY
     MORNING FOR CTZ002>004.
MA...WINTER WEATHER ADVISORY FROM NOON SUNDAY TO 7 AM EST MONDAY
     FOR MAZ002>008-010-014-023-024-026.
     WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY
     MORNING FOR MAZ009-011>013-015>022.
RI...WINTER WEATHER ADVISORY FROM NOON SUNDAY TO 7 AM EST MONDAY
     FOR RIZ008.
     WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY
     MORNING FOR RIZ001>007.
MARINE...NONE.

&&

$$

SYNOPSIS...DOODY/SIPPRELL
NEAR TERM...SIPPRELL
SHORT TERM...SIPPRELL
LONG TERM...DOODY
AVIATION...DOODY/SIPPRELL
MARINE...DOODY/SIPPRELL




000
FXUS61 KGYX 282000
AFDGYX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
300 PM EST SAT FEB 28 2015

.SYNOPSIS...
HIGH PRESSURE WILL CREST OVER THE REGION THIS EVENING BEFORE
SHIFTING OFFSHORE SUNDAY. WEAK LOW PRESSURE CROSSES THE REGION
SUNDAY NIGHT...PRODUCING SOME ACCUMULATING SNOW...BEFORE MOVING
INTO THE CANADIAN MARITIMES ON MONDAY. HIGH PRESSURE CROSSES THE
AREA MONDAY NIGHT AND TUESDAY. LOW PRESSURE WILL MOVE OUT OF THE
GREAT LAKES TUESDAY NIGHT AND WILL TRACK NORTHEAST THROUGH THE ST
LAWRENCE VALLEY ON WEDNESDAY...BRINGING A ROUND OF MIXED
PRECIPITATION TO THE AREA. A COLD FRONT FOLLOWS WEDNESDAY NIGHT.
HIGH PRESSURE BUILDS IN FOR THE END OF THE WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
THE COLDEST MONTH EVER FOR PORTLAND MAINE WILL BE IN THE BOOKS
SHORTLY. LAST NIGHT WAS NEAR RECORD COLD AS WELL...WITH A LOW OF
MINUS 7 IN THE FOREST CITY. THIS IS JUST SHY OF THE RECORD LOW OF
MINUS 9 SET BACK IN 1950.

WITH CLEAR SKIES AND LIGHT WINDS...EXPECT RADIATIONAL COOLING ONCE
AGAIN TONIGHT. WILL FORECAST ON THE LOWER END OF THE 12Z MODEL
SUITE WITH READINGS APPROACHING ZERO NEAR THE COASTLINE AND BELOW
ZERO OVER INTERIOR LOCATIONS. HIGH CLOUDS WILL BE ARRIVING LATER
TONIGHT. THIS MAY KEEP READINGS FROM TRUELY BOTTOMING OUT AS WAS
THE CASE LAST NIGHT.

&&

.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
A BROAD AND WEAK AREA OF WARM AIR ADVECTION WILL ALLOW CLOUDS TO
THICKEN ON SUNDAY ACROSS THE FORECAST AREA. LIGHT SNOW WILL BREAK
OUT SUNDAY NIGHT AS THIS DEVELOPING MOISTURE INTERACTS WITH AN
APPROACHING UPPER LEVEL TROUGH.

SURFACE LOW PRESSURE WILL FORM IN THE GULF OF MAINE LATE SUNDAY
NIGHT...BUT LIKELY TOO LATE TO BRING APPRECIABLE MOISTURE AND
SNOWFALL TO THE REGION. NEVERTHELESS...THERE WILL BE A TWO TO AS
MUCH AS FOUR INCHES OF SNOW OVER SOUTHERNMOST PORTIONS OF THE
FORECAST AREA. FURTHER TO THE NORTH...AS HAS BEEN THE CASE MUCH OF
THIS WINTER...LESS SNOW WILL FALL.

TEMPERATURES WILL BE MODERATING BUT STILL BELOW NORMAL FOR THIS
TIME OF THE YEAR.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
A SURFACE LOW EXITS RAPIDLY EAST INTO THE MARITIMES MONDAY WHILE
THE UPPER TROF MOVES THROUGH NORTHERN NEW ENGLAND. THE
PRECIPITATION WILL QUICKLY COME TO AN END EARLY MONDAY AS
DOWNSLOPING NORTHWEST WINDS KICK IN. HIGH PRESSURE BUILDS INTO THE
AREA MONDAY NIGHT AND TUESDAY. A FAST MOVING SHORT WAVE WITH
ASSOCIATED WARM AIR ADVECTION OVERUNNING PRECIPITATION WILL MOVE
INTO THE AREA TUESDAY NIGHT IN THE FORM OF SNOW. SEVERAL INCHES OF
SNOW IS EXPECTED THROUGHOUT THE AREA. BY WEDNESDAY MORNING A BRIEF
CHANGEOVER TO A MIX OF RAIN OR SNOW SHOWERS OVER SOUTHERN AREAS IS
POSSIBLE BEFORE THE PRECIPITATION ENDS AS LOW AND MID LEVEL
TEMPERATURES MAY WARM ABOVE CRITICAL LEVELS. BY LATE WEDNESDAY
MORNING A COLD FRONT MOVES ACROSS THE AREA AND THEN OFFSHORE WITH
CLEARING BEHIND THE FRONT. HIGH PRESSURE BUILDS INTO THE REGION
FOR THURSDAY AND FRIDAY WITH FAIR CONDITIONS.

TEMPERATURES WILL GENERALLY REMAIN BELOW NORMAL FOR THE WEEK. USED
A BLEND OF THE MODELS FOR TEMPERATURES AND POPS.

&&

.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
SHORT TERM...VFR CONDITIONS DETEORATING TO MVFR AND IFR SUNDAY
NIGHT IN LIGHT SNOW.

LONG TERM...
MVFR TO IFR CONDITIONS EARLY MONDAY WILL IMPROVE TO VFR BY LATE
MORNING MONDAY AND CONTINUE THROUGH TUESDAY. TUESDAY NIGHT MVFR TO
IFR CONDITIONS WILL DEVELOP AND CONTINUE INTO WEDNESDAY MORNING.
CONDITIONS WILL RETURN TO VFR BY WEDNESDAY AFTERNOON AND CONTINUE
THROUGH FRIDAY.

&&

.MARINE...
SHORT TERM...NO FLAGS. WINDS BELOW SCA THRESHOLDS AS WELL AS SEAS
IN THE SHORT TERM PORTION OF THE FORECAST.

LONG TERM...EXPECT TO NEED A STRONG SCA MONDAY AFT INTO MON NIGHT
IN AN INCREASING WEST FLOW...WINDS DIMINISH LATE MON NIGHT. SCA
MAY BE NEEDED AGAIN IN A SOUTH TO SOUTHWEST FLOW LATE TUE NIGHT
AND WEDNESDAY.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.

&&

$$




000
FXUS61 KGYX 282000
AFDGYX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
300 PM EST SAT FEB 28 2015

.SYNOPSIS...
HIGH PRESSURE WILL CREST OVER THE REGION THIS EVENING BEFORE
SHIFTING OFFSHORE SUNDAY. WEAK LOW PRESSURE CROSSES THE REGION
SUNDAY NIGHT...PRODUCING SOME ACCUMULATING SNOW...BEFORE MOVING
INTO THE CANADIAN MARITIMES ON MONDAY. HIGH PRESSURE CROSSES THE
AREA MONDAY NIGHT AND TUESDAY. LOW PRESSURE WILL MOVE OUT OF THE
GREAT LAKES TUESDAY NIGHT AND WILL TRACK NORTHEAST THROUGH THE ST
LAWRENCE VALLEY ON WEDNESDAY...BRINGING A ROUND OF MIXED
PRECIPITATION TO THE AREA. A COLD FRONT FOLLOWS WEDNESDAY NIGHT.
HIGH PRESSURE BUILDS IN FOR THE END OF THE WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
THE COLDEST MONTH EVER FOR PORTLAND MAINE WILL BE IN THE BOOKS
SHORTLY. LAST NIGHT WAS NEAR RECORD COLD AS WELL...WITH A LOW OF
MINUS 7 IN THE FOREST CITY. THIS IS JUST SHY OF THE RECORD LOW OF
MINUS 9 SET BACK IN 1950.

WITH CLEAR SKIES AND LIGHT WINDS...EXPECT RADIATIONAL COOLING ONCE
AGAIN TONIGHT. WILL FORECAST ON THE LOWER END OF THE 12Z MODEL
SUITE WITH READINGS APPROACHING ZERO NEAR THE COASTLINE AND BELOW
ZERO OVER INTERIOR LOCATIONS. HIGH CLOUDS WILL BE ARRIVING LATER
TONIGHT. THIS MAY KEEP READINGS FROM TRUELY BOTTOMING OUT AS WAS
THE CASE LAST NIGHT.

&&

.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
A BROAD AND WEAK AREA OF WARM AIR ADVECTION WILL ALLOW CLOUDS TO
THICKEN ON SUNDAY ACROSS THE FORECAST AREA. LIGHT SNOW WILL BREAK
OUT SUNDAY NIGHT AS THIS DEVELOPING MOISTURE INTERACTS WITH AN
APPROACHING UPPER LEVEL TROUGH.

SURFACE LOW PRESSURE WILL FORM IN THE GULF OF MAINE LATE SUNDAY
NIGHT...BUT LIKELY TOO LATE TO BRING APPRECIABLE MOISTURE AND
SNOWFALL TO THE REGION. NEVERTHELESS...THERE WILL BE A TWO TO AS
MUCH AS FOUR INCHES OF SNOW OVER SOUTHERNMOST PORTIONS OF THE
FORECAST AREA. FURTHER TO THE NORTH...AS HAS BEEN THE CASE MUCH OF
THIS WINTER...LESS SNOW WILL FALL.

TEMPERATURES WILL BE MODERATING BUT STILL BELOW NORMAL FOR THIS
TIME OF THE YEAR.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
A SURFACE LOW EXITS RAPIDLY EAST INTO THE MARITIMES MONDAY WHILE
THE UPPER TROF MOVES THROUGH NORTHERN NEW ENGLAND. THE
PRECIPITATION WILL QUICKLY COME TO AN END EARLY MONDAY AS
DOWNSLOPING NORTHWEST WINDS KICK IN. HIGH PRESSURE BUILDS INTO THE
AREA MONDAY NIGHT AND TUESDAY. A FAST MOVING SHORT WAVE WITH
ASSOCIATED WARM AIR ADVECTION OVERUNNING PRECIPITATION WILL MOVE
INTO THE AREA TUESDAY NIGHT IN THE FORM OF SNOW. SEVERAL INCHES OF
SNOW IS EXPECTED THROUGHOUT THE AREA. BY WEDNESDAY MORNING A BRIEF
CHANGEOVER TO A MIX OF RAIN OR SNOW SHOWERS OVER SOUTHERN AREAS IS
POSSIBLE BEFORE THE PRECIPITATION ENDS AS LOW AND MID LEVEL
TEMPERATURES MAY WARM ABOVE CRITICAL LEVELS. BY LATE WEDNESDAY
MORNING A COLD FRONT MOVES ACROSS THE AREA AND THEN OFFSHORE WITH
CLEARING BEHIND THE FRONT. HIGH PRESSURE BUILDS INTO THE REGION
FOR THURSDAY AND FRIDAY WITH FAIR CONDITIONS.

TEMPERATURES WILL GENERALLY REMAIN BELOW NORMAL FOR THE WEEK. USED
A BLEND OF THE MODELS FOR TEMPERATURES AND POPS.

&&

.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
SHORT TERM...VFR CONDITIONS DETEORATING TO MVFR AND IFR SUNDAY
NIGHT IN LIGHT SNOW.

LONG TERM...
MVFR TO IFR CONDITIONS EARLY MONDAY WILL IMPROVE TO VFR BY LATE
MORNING MONDAY AND CONTINUE THROUGH TUESDAY. TUESDAY NIGHT MVFR TO
IFR CONDITIONS WILL DEVELOP AND CONTINUE INTO WEDNESDAY MORNING.
CONDITIONS WILL RETURN TO VFR BY WEDNESDAY AFTERNOON AND CONTINUE
THROUGH FRIDAY.

&&

.MARINE...
SHORT TERM...NO FLAGS. WINDS BELOW SCA THRESHOLDS AS WELL AS SEAS
IN THE SHORT TERM PORTION OF THE FORECAST.

LONG TERM...EXPECT TO NEED A STRONG SCA MONDAY AFT INTO MON NIGHT
IN AN INCREASING WEST FLOW...WINDS DIMINISH LATE MON NIGHT. SCA
MAY BE NEEDED AGAIN IN A SOUTH TO SOUTHWEST FLOW LATE TUE NIGHT
AND WEDNESDAY.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.

&&

$$



000
FXUS61 KBOX 281723
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
1223 PM EST SAT FEB 28 2015

.SYNOPSIS...

A FAST MOVING LOW PRESSURE SYSTEM WILL BRING ACCUMULATING SNOW TO
THE REGION LATE SUNDAY INTO SUNDAY NIGHT...WITH THE HIGHEST AMOUNTS
EXPECTED SOUTH OF THE MASSACHUSETTS TURNPIKE AND AWAY FROM THE
IMMEDIATE SOUTH COAST. ANOTHER STORM IS LIKELY TUESDAY NIGHT INTO
WEDNESDAY...WITH SNOW AND MIXED PRECIPITATION LIKELY CHANGING TO
RAIN. COLD AND DRY CONDITIONS RETURN FOR THE END OF NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...

1230 PM UPDATE...

NO MAJOR CHANGES. ONLY MODIFICATIONS TO TEMPERATURES AND
DEWPOINTS TO BRING THEM MORE IN-LINE WITH TRENDS.

PREVIOUS DISCUSSION...

HIGH PRESSURE OVERHEAD WILL ALLOW FOR SUNNY SKIES AND LIGHT WINDS.
TEMPERATURESS SHOULD RECOVER INTO THE MIDDLE TO UPPER 20S IN MOST
LOCATIONS...BUT THAT IS STILL AROUND 15 DEGREES BELOW NORMAL FOR
THE LAST DAY OF FEBRUARY. HOWEVER...THE INCREASING LATE FEBRUARY
SUN ANGLE AND LIGHT WINDS WILL MAKE IT SOMEWHAT MORE BEARABLE THAN
OUR RECENT COLD WAVES.

TONIGHT...

HIGH PRESSURE OVERHEAD WILL ALLOW FOR ANOTHER EXCELLENT NIGHT OF
RADIATIONAL COOLING. THE NORMALLY COLDEST OUTLYING LOCATIONS WILL
DROP TO BETWEEN 5 AND 15 BELOW ZERO...WHILE MAINLY SINGLE DIGITS
CAN BE EXPECTED FOR THE REST OF THE REGION. THE ONE FLY IN THE
OINTMENT IS WE ARE EXPECTING SOME MID/HIGH CLOUDS TO INCREASE FROM
THE WEST AFTER MIDNIGHT. IF THEY COME IN A BIT EARLIER THEN
EXPECTED OUR TEMPERATURE FORECAST MIGHT BE TOO COLD.

&&

.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...

*** ACCUMULATING SNOW LATE SUNDAY AND ESPECIALLY SUNDAY NIGHT WITH
  THE HIGHEST AMOUNTS EXPECTED SOUTH OF THE MA TURNPIKE AND AWAY
  FROM THE IMMEDIATE SOUTH COAST ***

A DIGGING SHORTWAVE WILL DROP TOWARDS THE GREAT LAKES ON SUNDAY.
THIS WILL ALLOW FOR AN OVERRUNNING SETUP ACROSS SOUTHERN NEW
ENGLAND. A NICE FRONTOGENESIS SIGNATURE WITH A DEVELOPING LOW
LEVEL JET SHOULD RESULT IN A GOOD SLUG OF PRECIPITATION SUNDAY
EVENING INTO SUNDAY NIGHT. MOST MODELS ARE SHOWING A WEAK
SECONDARY LOW PRESSURE DEVELOPING NEAR THE SOUTH COAST. THIS WILL
HELP TO BACK AND STRENGTHEN THE LOW LEVEL JET ALONG WITH SOME
SURFACE CONVERGENCE RESULTING IN THE RISK FOR SOME HIGH
PRECIPITATION TOTALS SOUTH OF THE MA TURNPIKE WHICH WILL EXPLAIN
MORE BELOW.

1} TIMING AND PTYPE:

DRY WEATHER SHOULD PREVAIL SUNDAY MORNING. MID LEVEL WARM
ADVECTION SHOULD ALLOW LIGHT SNOW TO DEVELOP DURING THE AFTERNOON
ACROSS THE INTERIOR...REACHING THE COASTAL PLAIN BY LATE
AFTERNOON/EARLY EVENING. THE SNOW WILL INITIALLY BE LIGHT...BUT
EXPECT THE SNOW TO PICKUP IN INTENSITY SUNDAY EVENING AND
OVERNIGHT AS THE LOW LEVEL JET/FORCING INCREASE. MODEL SOUNDINGS
SHOW A PERIOD OF DECENT OMEGA IN THE PRIME SNOW GROWTH REGION.
SYSTEM IS FAIRLY PROGRESSIVE...SO THE SNOW SHOULD BE OVER EARLY
MONDAY MORNING AND BEFORE RUSH HOUR STARTS.

PTYPE WILL PROBABLY BE ALL SNOW FOR A LOT OF THE REGION. IT BECOMES
MORE UNCERTAIN ACROSS SOUTHERN RI AND FAR SOUTHEAST MA. THE NAM
MODEL IS AN OUTLIER AND MOST AGGRESSIVE IN BRINGING A SURGE OF
WARM MID LEVEL AIR NORTHWARD...WHICH WOULD CHANGE PTYPE TO RAIN
FOR JUST ABOUT ALL OF RHODE ISLAND AND SOUTHEAST MA SUN NIGHT.
HOWEVER...MOST OF THE OTHER GUIDANCE KEEPS PTYPE SNOW EXCEPT FOR
AREAS NEAR THE SOUTH COAST/CAPE/ISLANDS. SO FOR NOW WILL KEEP THE
CHANGE OVER LINE JUST SOUTH OF THE TAUNTON TO PROVIDENCE
CORRIDOR...BUT THIS MAY NEED TO BE ADJUSTED BASED ON LATEST MODEL
DATA.

2)SNOW ACCUMULATIONS AND HEADLINES:

THIS LOOKS TO BE A HIGH END WINTER WEATHER ADVISORY OR LOW END
WARNING FOR MUCH OF THE REGION. WE ARE GENERALLY EXPECTING
SNOWFALL AMOUNTS OF BETWEEN 3 AND 7 INCHES...AWAY FROM THE SOUTH
COAST WHERE PTYPE ISSUES WILL BE MORE PROBLEMATIC. THE NAM IS
HEAVIER ON QPF AND WE OPTED TO GO WITH A GFS/ECMWF BLEND. EVEN
THESE MODELS STILL HAVE BETWEEN 0.40 TO 0.60 INCHES OF PRECIP FROM
NEAR THE PIKE TO THE SOUTH COAST. THIS SEEMS TO BE IN RESPONSE TO
A WEAK WAVE DEVELOPING NEAR THE SOUTH COAST...ALLOWING FOR A MORE
BACKED LOW LEVEL JET AND BETTER SURFACE CONVERGENCE. WITH PRETTY
GOOD OMEGA IN THE SNOW GROWTH REGION...SNOWFALL RATIOS MAY BE
BETTER THAN 10 TO 1 RATIOS.

WITH THAT SAID...FELT IT IS WORTH A WINTER STORM WATCH FROM NEAR THE
PIKE TO AREAS INLAND FROM THE SOUTH COAST...WHERE PTYPE WILL
PROBABLY END UP AS MAINLY SNOW.  THIS IS FOR THE POTENTIAL OF 4 TO 7
INCHES OF SNOW. WE ARE FAIRLY CONFIDENCE IN WIDESPREAD 3 TO 4
INCH AMOUNTS...BUT CONFIDENCE IS LOWER ON WHETHER OR NOT WE SEE
THE 6 TO 7 INCH AMOUNTS. HOWEVER...WE ONLY NEED 50 PERCENT
CONFIDENCE IN THOSE HIGHER TOTALS OCCURRING TO ISSUE THE WATCH AND
IT GIVES THE NEXT SHIFT SOME MORE OPTIONS.

3) FORECAST UNCERTAINTY:

HOW MUCH SNOW WE ACTUALLY RECEIVE WILL HAVE A LOT TO DO WITH HOW
QUICKLY THE SECONDARY WAVE OF LOW PRESSURE DEVELOPS AND HOW FAR
NORTH THE RAIN/SNOW LINE GETS. THE NAM MODEL IS STRONGEST WITH
THE DEVELOPMENT OF THIS WAVE AND HENCE HAS THE HIGHEST QPF...BUT
DOES INTRODUCE MORE PTYPE ISSUES. MEANWHILE...THE GGEM IS THE
WEAKEST WITH THIS DEVELOPMENT AND BARELY HAS ADVISORY LEVEL SNOW
FOR THE REGION. CURRENTLY WE ARE LEANING TOWARDS A GFS/ECMWF
COMPROMISE...RESULTING IN 3 TO 7 INCHES OF SNOW WITH THE HIGHEST
AMOUNTS SOUTH OF PIKE AND AWAY FROM THE SOUTH COAST.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...

HIGHLIGHTS...

*  CONDITIONS IMPROVE MONDAY
*  ANOTHER STORM POSSIBLE TUE NIGHT INTO WED...WITH SNOW OR
   MIXED PRECIP LIKELY CHANGING TO RAIN
*  COLD AND DRY TOWARD THE END OF THE WEEK

OVERVIEW AND MODEL PREFERENCES...

ONE THING IS FOR CERTAIN...WITH LITTLE CHANGE IN THE NAO/AO AND
THE PNA EXPECTED TO REBOUND FROM NEGATIVE VALUES BACK TOWARD A
MORE NEUTRAL SOLUTION...THE COLD AIR AND LONGWAVE TROF LOOK TO
REMAIN THROUGH THE LONG TERM FORECAST. THE ONLY CAVEAT WILL BE IN
THE LOW LVLS ON WED...WHEN A ROBUST SW LLJ WILL ALLOW LOW-MID LVL
TEMPS TO WARM CLOSER TO ABOVE CLIMATOLOGICAL NORMALS. HOWEVER...
THE COLD AIR INITIALLY IN PLACE WILL LEAD TO P-TYPE ISSUES FOR THE
MID WEEK SYSTEM. ECMWF DETERMINISTIC REMAINS THE MOST ROBUST OF
THE OPERATIONAL MODELS...WITH HIGHER AMPLIFICATION IN THE FLOW
PATTERN THAN THE GFS AND UKMET. IT STARTS MUCH COLDER...BUT ENDS
MUCH WARMER. HOWEVER...DO NOTE THAT SOME OF THE GEFS AND ECENS
ENSEMBLES AGREE WITH THE ECMWF. THEREFORE...WILL BE USING THE
ENSEMBLE BLEND AS A BASELINE AS THIS TAKES INTO ACCOUNT BOTH THE
MORE PROGRESSIVE /AND ULTIMATELY LESS ROBUST WITH THE THERMAL
DIFFERENCES/ AND THE POTENTIAL FOR A MORE DYNAMIC SYSTEM. WILL USE
THIS BLEND THROUGH THE REMAINDER OF THE FORECAST AS WELL.

DETAILS...

MONDAY...

MORNING SNOWS COME TO AN END EARLY ACROSS E MA...AND FLURRIES
DISSIPATE THROUGH THE BERKSHIRES AND LITCHFIELD HILLS AS DRY NW
FLOW MOVES IN. BLUSTERY CONDITIONS EXPECTED...AND EVEN THROUGH
HIGHS WILL STILL BE MAKING IT INTO THE LOW-UPPER 30S...NW WINDS
WITH GUSTS 25-35 MPH AT TIMES WILL YIELD WIND CHILLS STRUGGLING
INTO THE LOW 20S.

MONDAY NIGHT INTO TUESDAY...

HIGH PRES WILL MOVE ACROSS THE REGION. DRY CONDITIONS DOMINATE
ALTHOUGH WITH TEMPS REMAINING BELOW NORMAL.

TUESDAY NIGHT INTO THURSDAY...

MODEL CONSENSUS IS NOW GENERALLY IN AGREEMENT THAT BOTH THE NRN
AND SRN STREAMS PHASE IN SOME FASHION ACROSS THE CENTRAL CONUS
WITH THE FORMATION OF LOW PRES WHICH IS EXPECTED TO SLIDE ACROSS
SRN CANADA. WARM FRONT WILL APPROACH...BUT GIVEN DEEP SNOWPACK THE
LOW LVL FRONT MAY ACTUAL STALL NEAR THE S COAST AS THE LOW MOVES
OVER AS THE UPPER WARM FRONT SLIDES INTO CENTRAL NEW ENGLAND. THIS
PRESENTS A GOOD OVERRUNNING SITUATION WITH STRONG 50-60 KT H92 LLJ
OUT OF THE SW. GIVEN THAT THIS SYSTEM IS ASSOCIATED WITH THE SRN
STREAM...IT ALSO CARRIES WITH IT A FAIR AMOUNT OF MOISTURE AS
PWATS LOOK TO REACH 2-3 STD DEVIATIONS ABOVE NORMAL

SO ALL IN ALL..PLENTY OF INGREDIENTS FOR HEAVY PRECIP ACROSS THE
AREA. THE QUESTION WILL BE TYPE...ALL GUIDANCE BEGIN COLD ENOUGH
FOR SNOW AT ONSET TUE NIGHT INTO EARLY WED. ECMWF WOULD SUGGEST
MUCH MORE AND BETTER LIFT IN THE SNOW GROWTH REGION...SO THERE IS
THAT TO CONSIDER. IN ANY CASE...WILL NEED TO AT LEAST WATCH FOR
POTENTIAL WARNING LEVEL SNOWFALL BEFORE THE WARM AIR BEGINS TO
BUILD IN FROM S TO N THROUGH THE DAY ON WED. EVEN THOUGH THE ECMWF
STARTS THE COLDEST...IT ENDS AS THE WARMEST SOLUTION...BRINGING
THE H92 +8C LINE ALL THE WAY INTO CENTRAL MA. SO WE DO EXPECT A
GRADUAL SHIFT TO A WINTRY MIX INCLUDING SLEET AND FREEZING RAIN
FOR A TIME GIVEN THE DEEP SNOWPACK ACROSS THE REGION. SOME AREAS
OF WRN MA...AND THE HILLS OF NRN CT MAY ACTUALLY STAY AS A MIX OF
SLEET FREEZING RAIN AND EVEN MAYBE SOME SNOW GIVEN THAT THE SFC
WARM FRONT MAY STALL. WILL HAVE TO WATCH FOR ICY CONDITIONS WITH
AS MUCH AS A QUARTER INCH OF ICE NOT OUT OF THE QUESTION WHERE IT
DOESN/T SWITCH TO RAIN WITH MELTING /BEST CHANCE OF RAIN/MELT IS
IN RI/CT AND PORTIONS OF MASS E OF I-495 AND S OF THE MASS PIKE/.
HEAVY RAIN A THREAT TOO GIVEN UPPER LVL INSTABILITY AND ROBUST
LLJ...SO WHERE MELTING AND HEAVY RAIN ARE OBSERVED...POOR DRAINAGE
FLOODING IS A POSSIBILITY WHERE SNOW CLOGS AREA DRAINS.

THIS HEAVY MIXED PRECIP EVENT COULD LINGER INTO THU...THE MORE
AMPLIFIED ECMWF AND SEVERAL ECENS/GEFS MEMBERS SUGGEST THAT THE
LEFTOVER COLD FRONT STALLS WITH YET ANOTHER WEAK WAVE OF LOW PRES
MOVING THROUGH THU. OTHER SOLUTIONS ARE MORE PROGRESSIVE AND HAVE
LESS QPF /SNOW POTENTIALLY/ ON THE BACK END. HOWEVER...BY THU
AFTERNOON/EVENING...CONDITIONS SHOULD BE IMPROVING /ALTHOUGH WITH
RAPID TEMPERATURE DROP/.

LATE NEXT WEEK...

EVEN THOUGH THERE IS UNCERTAINTY WITH HOW AMPLIFIED THE PATTERN
IS BY LATE WEEK. IT APPEARS A PERIOD OF DRY BUT COLD WX IS LIKELY
AS ARCTIC AIR ONCE AGAIN SHIFTS IN BEHIND THE EXITING MID WEEK
SYSTEM.

&&

.AVIATION /17Z SATURDAY THROUGH WEDNESDAY/...

FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TODAY THROUGH SUNDAY NIGHT/...

18Z UPDATE...

TODAY THROUGH SUNDAY MORNING...HIGH CONFIDENCE.

VFR. INCREASING MID-LEVEL CLOUDS LATE.

SUNDAY AFTERNOON INTO MONDAY MORNING...MODERATE CONFIDENCE.

SNOW OVERSPREADS THE REGION W-E. CIGS/VSBYS DETERIORATE TO MVFR-
IFR BY EARLY EVENING...WIDESPREAD IFR-LIFR SUNDAY NIGHT. SN MAY
MIX WITH OR CHANGE TO RA FOR A TIME ACROSS PORTIONS OF S-COASTAL
RI AND MA...INCLUDING THE CAPE AND ISLANDS. PRECIP SHOULD RAPIDLY
END FROM W-E TOWARD DAYBREAK MONDAY....IMPROVING CONDITIONS.

KBOS TAF...HIGH CONFIDENCE. VFR INTO SUNDAY MORNING.

KBDL TAF...HIGH CONFIDENCE. VFR INTO SUNDAY MORNING.

OUTLOOK...MONDAY THROUGH WEDNESDAY...

MONDAY...HIGH CONFIDENCE.

CONDITIONS IMPROVE EARLY FROM IFR/MVFR IN SNOWS AND LOW CIGS...
WITH VFR EXPECTED EVERYWHERE BY AFTERNOON. NW WINDS IN THE
AFTERNOON WITH GUSTS 25-30 KT.

MON NIGHT INTO TUE...HIGH CONFIDENCE.

MAINLY VFR. GRADUALLY LOWERING CIGS ON TUE.

TUE NIGHT INTO WED...MODERATE CONFIDENCE.

MIXED WINTRY PRECIP LIKELY STARTS AS ALL SNOW...TRANSITIONS TO A
MIX OF SLEET AND FREEZING RAIN...THEN TO ALL RAIN DURING THE DAY
ON WED. SOME SNOW AND ICE ACCUMULATIONS ARE LIKELY WITH IFR OR
POTENTIALLY EVEN LIFR CONDITIONS AT TIMES.

&&

.MARINE...

FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /THROUGH SATURDAY NIGHT/...HIGH CONFIDENCE.

1230 PM UPDATE...NO MAJOR CHANGES.

HIGH PRESSURE NEARBY WILL KEEP WINDS/SEAS WELL BELOW SMALL CRAFT
ADVISORY THRESHOLDS INTO SUNDAY MORNING. A WEAK WAVE OF LOW
PRESSURE MOVES ACROSS THE WATERS LATE SUN INTO SUN NIGHT...BUT
WEAK PRESSURE GRADIENT SHOULD KEEP WINDS/SEAS BELOW SMALL CRAFT
THRESHOLDS.

OUTLOOK...SUNDAY THROUGH WEDNESDAY...

MONDAY INTO MONDAY NIGHT...HIGH CONFIDENCE.

SW WINDS SHIFT TO THE NW DURING THE DAYLIGHT HOURS AS A COLD
FRONT SWEEPS ACROSS THE WATERS. ONCE WINDS SHIFT NW IN THE
AFTERNOON EXPECT GALE FORCE GUSTS 35-40KT. COLDER AIR TUE NIGHT
COULD LEAD TO LIGHT FREEZING SPRAY.

TUESDAY...MODERATE CONFIDENCE.

WINDS GRADUALLY DIMINISH OUT OF THE W-NW BUT SEAS ARE LIKELY TO
REMAIN ELEVATED 5-8FT ON THE OCEAN WATERS. SMALL CRAFT ADVISORIES
WILL LIKELY BE NEEDED.

TUESDAY NIGHT INTO WEDNESDAY...MODERATE CONFIDENCE.

SNOW CHANGES TO RAIN TUE NIGHT WITH LOW VSBYS OVER THE WATERS.
WINDS OUT OF THE S MAINLY AROUND 25-30 KT AT MOST. SEAS BUILD
12-15 FT BY DAYTIME ON WED ON SE OCEAN WATERS. SMALL CRAFT
ADVISORIES WILL LIKELY BE NEEDED.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...

CT...WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH LATE SUNDAY
     NIGHT FOR CTZ002>004.
MA...WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH LATE SUNDAY
     NIGHT FOR MAZ009-011>013-015>019.
RI...WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH LATE SUNDAY
     NIGHT FOR RIZ001>004.
MARINE...NONE.

&&

$$

SYNOPSIS...FRANK/DOODY
NEAR TERM...FRANK/DOODY/SIPPRELL
SHORT TERM...FRANK
LONG TERM...DOODY
AVIATION...FRANK/DOODY/SIPPRELL
MARINE...FRANK/DOODY



000
FXUS61 KBOX 281723
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
1223 PM EST SAT FEB 28 2015

.SYNOPSIS...

A FAST MOVING LOW PRESSURE SYSTEM WILL BRING ACCUMULATING SNOW TO
THE REGION LATE SUNDAY INTO SUNDAY NIGHT...WITH THE HIGHEST AMOUNTS
EXPECTED SOUTH OF THE MASSACHUSETTS TURNPIKE AND AWAY FROM THE
IMMEDIATE SOUTH COAST. ANOTHER STORM IS LIKELY TUESDAY NIGHT INTO
WEDNESDAY...WITH SNOW AND MIXED PRECIPITATION LIKELY CHANGING TO
RAIN. COLD AND DRY CONDITIONS RETURN FOR THE END OF NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...

1230 PM UPDATE...

NO MAJOR CHANGES. ONLY MODIFICATIONS TO TEMPERATURES AND
DEWPOINTS TO BRING THEM MORE IN-LINE WITH TRENDS.

PREVIOUS DISCUSSION...

HIGH PRESSURE OVERHEAD WILL ALLOW FOR SUNNY SKIES AND LIGHT WINDS.
TEMPERATURESS SHOULD RECOVER INTO THE MIDDLE TO UPPER 20S IN MOST
LOCATIONS...BUT THAT IS STILL AROUND 15 DEGREES BELOW NORMAL FOR
THE LAST DAY OF FEBRUARY. HOWEVER...THE INCREASING LATE FEBRUARY
SUN ANGLE AND LIGHT WINDS WILL MAKE IT SOMEWHAT MORE BEARABLE THAN
OUR RECENT COLD WAVES.

TONIGHT...

HIGH PRESSURE OVERHEAD WILL ALLOW FOR ANOTHER EXCELLENT NIGHT OF
RADIATIONAL COOLING. THE NORMALLY COLDEST OUTLYING LOCATIONS WILL
DROP TO BETWEEN 5 AND 15 BELOW ZERO...WHILE MAINLY SINGLE DIGITS
CAN BE EXPECTED FOR THE REST OF THE REGION. THE ONE FLY IN THE
OINTMENT IS WE ARE EXPECTING SOME MID/HIGH CLOUDS TO INCREASE FROM
THE WEST AFTER MIDNIGHT. IF THEY COME IN A BIT EARLIER THEN
EXPECTED OUR TEMPERATURE FORECAST MIGHT BE TOO COLD.

&&

.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...

*** ACCUMULATING SNOW LATE SUNDAY AND ESPECIALLY SUNDAY NIGHT WITH
  THE HIGHEST AMOUNTS EXPECTED SOUTH OF THE MA TURNPIKE AND AWAY
  FROM THE IMMEDIATE SOUTH COAST ***

A DIGGING SHORTWAVE WILL DROP TOWARDS THE GREAT LAKES ON SUNDAY.
THIS WILL ALLOW FOR AN OVERRUNNING SETUP ACROSS SOUTHERN NEW
ENGLAND. A NICE FRONTOGENESIS SIGNATURE WITH A DEVELOPING LOW
LEVEL JET SHOULD RESULT IN A GOOD SLUG OF PRECIPITATION SUNDAY
EVENING INTO SUNDAY NIGHT. MOST MODELS ARE SHOWING A WEAK
SECONDARY LOW PRESSURE DEVELOPING NEAR THE SOUTH COAST. THIS WILL
HELP TO BACK AND STRENGTHEN THE LOW LEVEL JET ALONG WITH SOME
SURFACE CONVERGENCE RESULTING IN THE RISK FOR SOME HIGH
PRECIPITATION TOTALS SOUTH OF THE MA TURNPIKE WHICH WILL EXPLAIN
MORE BELOW.

1} TIMING AND PTYPE:

DRY WEATHER SHOULD PREVAIL SUNDAY MORNING. MID LEVEL WARM
ADVECTION SHOULD ALLOW LIGHT SNOW TO DEVELOP DURING THE AFTERNOON
ACROSS THE INTERIOR...REACHING THE COASTAL PLAIN BY LATE
AFTERNOON/EARLY EVENING. THE SNOW WILL INITIALLY BE LIGHT...BUT
EXPECT THE SNOW TO PICKUP IN INTENSITY SUNDAY EVENING AND
OVERNIGHT AS THE LOW LEVEL JET/FORCING INCREASE. MODEL SOUNDINGS
SHOW A PERIOD OF DECENT OMEGA IN THE PRIME SNOW GROWTH REGION.
SYSTEM IS FAIRLY PROGRESSIVE...SO THE SNOW SHOULD BE OVER EARLY
MONDAY MORNING AND BEFORE RUSH HOUR STARTS.

PTYPE WILL PROBABLY BE ALL SNOW FOR A LOT OF THE REGION. IT BECOMES
MORE UNCERTAIN ACROSS SOUTHERN RI AND FAR SOUTHEAST MA. THE NAM
MODEL IS AN OUTLIER AND MOST AGGRESSIVE IN BRINGING A SURGE OF
WARM MID LEVEL AIR NORTHWARD...WHICH WOULD CHANGE PTYPE TO RAIN
FOR JUST ABOUT ALL OF RHODE ISLAND AND SOUTHEAST MA SUN NIGHT.
HOWEVER...MOST OF THE OTHER GUIDANCE KEEPS PTYPE SNOW EXCEPT FOR
AREAS NEAR THE SOUTH COAST/CAPE/ISLANDS. SO FOR NOW WILL KEEP THE
CHANGE OVER LINE JUST SOUTH OF THE TAUNTON TO PROVIDENCE
CORRIDOR...BUT THIS MAY NEED TO BE ADJUSTED BASED ON LATEST MODEL
DATA.

2)SNOW ACCUMULATIONS AND HEADLINES:

THIS LOOKS TO BE A HIGH END WINTER WEATHER ADVISORY OR LOW END
WARNING FOR MUCH OF THE REGION. WE ARE GENERALLY EXPECTING
SNOWFALL AMOUNTS OF BETWEEN 3 AND 7 INCHES...AWAY FROM THE SOUTH
COAST WHERE PTYPE ISSUES WILL BE MORE PROBLEMATIC. THE NAM IS
HEAVIER ON QPF AND WE OPTED TO GO WITH A GFS/ECMWF BLEND. EVEN
THESE MODELS STILL HAVE BETWEEN 0.40 TO 0.60 INCHES OF PRECIP FROM
NEAR THE PIKE TO THE SOUTH COAST. THIS SEEMS TO BE IN RESPONSE TO
A WEAK WAVE DEVELOPING NEAR THE SOUTH COAST...ALLOWING FOR A MORE
BACKED LOW LEVEL JET AND BETTER SURFACE CONVERGENCE. WITH PRETTY
GOOD OMEGA IN THE SNOW GROWTH REGION...SNOWFALL RATIOS MAY BE
BETTER THAN 10 TO 1 RATIOS.

WITH THAT SAID...FELT IT IS WORTH A WINTER STORM WATCH FROM NEAR THE
PIKE TO AREAS INLAND FROM THE SOUTH COAST...WHERE PTYPE WILL
PROBABLY END UP AS MAINLY SNOW.  THIS IS FOR THE POTENTIAL OF 4 TO 7
INCHES OF SNOW. WE ARE FAIRLY CONFIDENCE IN WIDESPREAD 3 TO 4
INCH AMOUNTS...BUT CONFIDENCE IS LOWER ON WHETHER OR NOT WE SEE
THE 6 TO 7 INCH AMOUNTS. HOWEVER...WE ONLY NEED 50 PERCENT
CONFIDENCE IN THOSE HIGHER TOTALS OCCURRING TO ISSUE THE WATCH AND
IT GIVES THE NEXT SHIFT SOME MORE OPTIONS.

3) FORECAST UNCERTAINTY:

HOW MUCH SNOW WE ACTUALLY RECEIVE WILL HAVE A LOT TO DO WITH HOW
QUICKLY THE SECONDARY WAVE OF LOW PRESSURE DEVELOPS AND HOW FAR
NORTH THE RAIN/SNOW LINE GETS. THE NAM MODEL IS STRONGEST WITH
THE DEVELOPMENT OF THIS WAVE AND HENCE HAS THE HIGHEST QPF...BUT
DOES INTRODUCE MORE PTYPE ISSUES. MEANWHILE...THE GGEM IS THE
WEAKEST WITH THIS DEVELOPMENT AND BARELY HAS ADVISORY LEVEL SNOW
FOR THE REGION. CURRENTLY WE ARE LEANING TOWARDS A GFS/ECMWF
COMPROMISE...RESULTING IN 3 TO 7 INCHES OF SNOW WITH THE HIGHEST
AMOUNTS SOUTH OF PIKE AND AWAY FROM THE SOUTH COAST.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...

HIGHLIGHTS...

*  CONDITIONS IMPROVE MONDAY
*  ANOTHER STORM POSSIBLE TUE NIGHT INTO WED...WITH SNOW OR
   MIXED PRECIP LIKELY CHANGING TO RAIN
*  COLD AND DRY TOWARD THE END OF THE WEEK

OVERVIEW AND MODEL PREFERENCES...

ONE THING IS FOR CERTAIN...WITH LITTLE CHANGE IN THE NAO/AO AND
THE PNA EXPECTED TO REBOUND FROM NEGATIVE VALUES BACK TOWARD A
MORE NEUTRAL SOLUTION...THE COLD AIR AND LONGWAVE TROF LOOK TO
REMAIN THROUGH THE LONG TERM FORECAST. THE ONLY CAVEAT WILL BE IN
THE LOW LVLS ON WED...WHEN A ROBUST SW LLJ WILL ALLOW LOW-MID LVL
TEMPS TO WARM CLOSER TO ABOVE CLIMATOLOGICAL NORMALS. HOWEVER...
THE COLD AIR INITIALLY IN PLACE WILL LEAD TO P-TYPE ISSUES FOR THE
MID WEEK SYSTEM. ECMWF DETERMINISTIC REMAINS THE MOST ROBUST OF
THE OPERATIONAL MODELS...WITH HIGHER AMPLIFICATION IN THE FLOW
PATTERN THAN THE GFS AND UKMET. IT STARTS MUCH COLDER...BUT ENDS
MUCH WARMER. HOWEVER...DO NOTE THAT SOME OF THE GEFS AND ECENS
ENSEMBLES AGREE WITH THE ECMWF. THEREFORE...WILL BE USING THE
ENSEMBLE BLEND AS A BASELINE AS THIS TAKES INTO ACCOUNT BOTH THE
MORE PROGRESSIVE /AND ULTIMATELY LESS ROBUST WITH THE THERMAL
DIFFERENCES/ AND THE POTENTIAL FOR A MORE DYNAMIC SYSTEM. WILL USE
THIS BLEND THROUGH THE REMAINDER OF THE FORECAST AS WELL.

DETAILS...

MONDAY...

MORNING SNOWS COME TO AN END EARLY ACROSS E MA...AND FLURRIES
DISSIPATE THROUGH THE BERKSHIRES AND LITCHFIELD HILLS AS DRY NW
FLOW MOVES IN. BLUSTERY CONDITIONS EXPECTED...AND EVEN THROUGH
HIGHS WILL STILL BE MAKING IT INTO THE LOW-UPPER 30S...NW WINDS
WITH GUSTS 25-35 MPH AT TIMES WILL YIELD WIND CHILLS STRUGGLING
INTO THE LOW 20S.

MONDAY NIGHT INTO TUESDAY...

HIGH PRES WILL MOVE ACROSS THE REGION. DRY CONDITIONS DOMINATE
ALTHOUGH WITH TEMPS REMAINING BELOW NORMAL.

TUESDAY NIGHT INTO THURSDAY...

MODEL CONSENSUS IS NOW GENERALLY IN AGREEMENT THAT BOTH THE NRN
AND SRN STREAMS PHASE IN SOME FASHION ACROSS THE CENTRAL CONUS
WITH THE FORMATION OF LOW PRES WHICH IS EXPECTED TO SLIDE ACROSS
SRN CANADA. WARM FRONT WILL APPROACH...BUT GIVEN DEEP SNOWPACK THE
LOW LVL FRONT MAY ACTUAL STALL NEAR THE S COAST AS THE LOW MOVES
OVER AS THE UPPER WARM FRONT SLIDES INTO CENTRAL NEW ENGLAND. THIS
PRESENTS A GOOD OVERRUNNING SITUATION WITH STRONG 50-60 KT H92 LLJ
OUT OF THE SW. GIVEN THAT THIS SYSTEM IS ASSOCIATED WITH THE SRN
STREAM...IT ALSO CARRIES WITH IT A FAIR AMOUNT OF MOISTURE AS
PWATS LOOK TO REACH 2-3 STD DEVIATIONS ABOVE NORMAL

SO ALL IN ALL..PLENTY OF INGREDIENTS FOR HEAVY PRECIP ACROSS THE
AREA. THE QUESTION WILL BE TYPE...ALL GUIDANCE BEGIN COLD ENOUGH
FOR SNOW AT ONSET TUE NIGHT INTO EARLY WED. ECMWF WOULD SUGGEST
MUCH MORE AND BETTER LIFT IN THE SNOW GROWTH REGION...SO THERE IS
THAT TO CONSIDER. IN ANY CASE...WILL NEED TO AT LEAST WATCH FOR
POTENTIAL WARNING LEVEL SNOWFALL BEFORE THE WARM AIR BEGINS TO
BUILD IN FROM S TO N THROUGH THE DAY ON WED. EVEN THOUGH THE ECMWF
STARTS THE COLDEST...IT ENDS AS THE WARMEST SOLUTION...BRINGING
THE H92 +8C LINE ALL THE WAY INTO CENTRAL MA. SO WE DO EXPECT A
GRADUAL SHIFT TO A WINTRY MIX INCLUDING SLEET AND FREEZING RAIN
FOR A TIME GIVEN THE DEEP SNOWPACK ACROSS THE REGION. SOME AREAS
OF WRN MA...AND THE HILLS OF NRN CT MAY ACTUALLY STAY AS A MIX OF
SLEET FREEZING RAIN AND EVEN MAYBE SOME SNOW GIVEN THAT THE SFC
WARM FRONT MAY STALL. WILL HAVE TO WATCH FOR ICY CONDITIONS WITH
AS MUCH AS A QUARTER INCH OF ICE NOT OUT OF THE QUESTION WHERE IT
DOESN/T SWITCH TO RAIN WITH MELTING /BEST CHANCE OF RAIN/MELT IS
IN RI/CT AND PORTIONS OF MASS E OF I-495 AND S OF THE MASS PIKE/.
HEAVY RAIN A THREAT TOO GIVEN UPPER LVL INSTABILITY AND ROBUST
LLJ...SO WHERE MELTING AND HEAVY RAIN ARE OBSERVED...POOR DRAINAGE
FLOODING IS A POSSIBILITY WHERE SNOW CLOGS AREA DRAINS.

THIS HEAVY MIXED PRECIP EVENT COULD LINGER INTO THU...THE MORE
AMPLIFIED ECMWF AND SEVERAL ECENS/GEFS MEMBERS SUGGEST THAT THE
LEFTOVER COLD FRONT STALLS WITH YET ANOTHER WEAK WAVE OF LOW PRES
MOVING THROUGH THU. OTHER SOLUTIONS ARE MORE PROGRESSIVE AND HAVE
LESS QPF /SNOW POTENTIALLY/ ON THE BACK END. HOWEVER...BY THU
AFTERNOON/EVENING...CONDITIONS SHOULD BE IMPROVING /ALTHOUGH WITH
RAPID TEMPERATURE DROP/.

LATE NEXT WEEK...

EVEN THOUGH THERE IS UNCERTAINTY WITH HOW AMPLIFIED THE PATTERN
IS BY LATE WEEK. IT APPEARS A PERIOD OF DRY BUT COLD WX IS LIKELY
AS ARCTIC AIR ONCE AGAIN SHIFTS IN BEHIND THE EXITING MID WEEK
SYSTEM.

&&

.AVIATION /17Z SATURDAY THROUGH WEDNESDAY/...

FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TODAY THROUGH SUNDAY NIGHT/...

18Z UPDATE...

TODAY THROUGH SUNDAY MORNING...HIGH CONFIDENCE.

VFR. INCREASING MID-LEVEL CLOUDS LATE.

SUNDAY AFTERNOON INTO MONDAY MORNING...MODERATE CONFIDENCE.

SNOW OVERSPREADS THE REGION W-E. CIGS/VSBYS DETERIORATE TO MVFR-
IFR BY EARLY EVENING...WIDESPREAD IFR-LIFR SUNDAY NIGHT. SN MAY
MIX WITH OR CHANGE TO RA FOR A TIME ACROSS PORTIONS OF S-COASTAL
RI AND MA...INCLUDING THE CAPE AND ISLANDS. PRECIP SHOULD RAPIDLY
END FROM W-E TOWARD DAYBREAK MONDAY....IMPROVING CONDITIONS.

KBOS TAF...HIGH CONFIDENCE. VFR INTO SUNDAY MORNING.

KBDL TAF...HIGH CONFIDENCE. VFR INTO SUNDAY MORNING.

OUTLOOK...MONDAY THROUGH WEDNESDAY...

MONDAY...HIGH CONFIDENCE.

CONDITIONS IMPROVE EARLY FROM IFR/MVFR IN SNOWS AND LOW CIGS...
WITH VFR EXPECTED EVERYWHERE BY AFTERNOON. NW WINDS IN THE
AFTERNOON WITH GUSTS 25-30 KT.

MON NIGHT INTO TUE...HIGH CONFIDENCE.

MAINLY VFR. GRADUALLY LOWERING CIGS ON TUE.

TUE NIGHT INTO WED...MODERATE CONFIDENCE.

MIXED WINTRY PRECIP LIKELY STARTS AS ALL SNOW...TRANSITIONS TO A
MIX OF SLEET AND FREEZING RAIN...THEN TO ALL RAIN DURING THE DAY
ON WED. SOME SNOW AND ICE ACCUMULATIONS ARE LIKELY WITH IFR OR
POTENTIALLY EVEN LIFR CONDITIONS AT TIMES.

&&

.MARINE...

FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /THROUGH SATURDAY NIGHT/...HIGH CONFIDENCE.

1230 PM UPDATE...NO MAJOR CHANGES.

HIGH PRESSURE NEARBY WILL KEEP WINDS/SEAS WELL BELOW SMALL CRAFT
ADVISORY THRESHOLDS INTO SUNDAY MORNING. A WEAK WAVE OF LOW
PRESSURE MOVES ACROSS THE WATERS LATE SUN INTO SUN NIGHT...BUT
WEAK PRESSURE GRADIENT SHOULD KEEP WINDS/SEAS BELOW SMALL CRAFT
THRESHOLDS.

OUTLOOK...SUNDAY THROUGH WEDNESDAY...

MONDAY INTO MONDAY NIGHT...HIGH CONFIDENCE.

SW WINDS SHIFT TO THE NW DURING THE DAYLIGHT HOURS AS A COLD
FRONT SWEEPS ACROSS THE WATERS. ONCE WINDS SHIFT NW IN THE
AFTERNOON EXPECT GALE FORCE GUSTS 35-40KT. COLDER AIR TUE NIGHT
COULD LEAD TO LIGHT FREEZING SPRAY.

TUESDAY...MODERATE CONFIDENCE.

WINDS GRADUALLY DIMINISH OUT OF THE W-NW BUT SEAS ARE LIKELY TO
REMAIN ELEVATED 5-8FT ON THE OCEAN WATERS. SMALL CRAFT ADVISORIES
WILL LIKELY BE NEEDED.

TUESDAY NIGHT INTO WEDNESDAY...MODERATE CONFIDENCE.

SNOW CHANGES TO RAIN TUE NIGHT WITH LOW VSBYS OVER THE WATERS.
WINDS OUT OF THE S MAINLY AROUND 25-30 KT AT MOST. SEAS BUILD
12-15 FT BY DAYTIME ON WED ON SE OCEAN WATERS. SMALL CRAFT
ADVISORIES WILL LIKELY BE NEEDED.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...

CT...WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH LATE SUNDAY
     NIGHT FOR CTZ002>004.
MA...WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH LATE SUNDAY
     NIGHT FOR MAZ009-011>013-015>019.
RI...WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH LATE SUNDAY
     NIGHT FOR RIZ001>004.
MARINE...NONE.

&&

$$

SYNOPSIS...FRANK/DOODY
NEAR TERM...FRANK/DOODY/SIPPRELL
SHORT TERM...FRANK
LONG TERM...DOODY
AVIATION...FRANK/DOODY/SIPPRELL
MARINE...FRANK/DOODY




000
FXUS61 KGYX 281703
AFDGYX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
1203 PM EST SAT FEB 28 2015

.SYNOPSIS...
HIGH PRESSURE WILL BUILD OVER THE REGION TODAY AND WILL SHIFT
OFFSHORE SUNDAY. WEAK LOW PRESSURE CROSSES THE REGION SUNDAY
NIGHT...PRODUCING SOME ACCUMULATING SNOW...BEFORE MOVING INTO THE
CANADIAN MARITIMES ON MONDAY. HIGH PRESSURE CROSSES THE AREA
MONDAY NIGHT AND TUESDAY. LOW PRESSURE WILL MOVE OUT OF THE GREAT
LAKES TUESDAY NIGHT AND WILL TRACK NORTHEAST THROUGH THE ST
LAWRENCE VALLEY ON WEDNESDAY...BRINGING A ROUND OF MIXED
PRECIPITATION TO THE AREA. A COLD FRONT FOLLOWS WEDNESDAY NIGHT.
HIGH PRESSURE BUILDS IN FOR THE END OF THE WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
UPDATE...
HAVE UPDATED THE GRIDS BASED ON CURRENT TRENDS AND CONDITIONS. -7
DEGREES IN PORTLAND LAST NIGHT WAS VERY CLOSE TO THE ALL-TIME
RECORD LOW OF -9. EXPECT TO FORECAST BELOW MODEL GUIDANCE AGAIN
TONIGHT FOR THE MIN TEMPERATURES.

RAISED MAX TEMPS BY A COUPLE DEGREES AS THE EXTREMELY DRY AIRMASS
CONTINUES TO ALLOW FOR SIGNIFICANT DIURNAL RANGES.

HAVE LOWERED THE FREEZING SPRAY ADVISORY WITH THIS PACKAGE.

PREV DISC...
HIGH PRESSURE WILL CONTINUE TO BUILD IN FROM THE WEST
TODAY PROVIDING SUNNY SKIES AND SLIGHTLY WARMER TEMPS. HIGHS WILL
RANGE FROM THE UPPER TEENS TO LOWER 20S NORTH AND MID TO UPPER 20S
SOUTH.

&&

.SHORT TERM /SUNDAY/...
HIGH PRESSURE WILL CREST OVER THE REGION TONIGHT. GOOD RADIATIONAL
COOLING WILL AGAIN SEND TEMPS WELL BELOW NORMAL BUT NOT QUITE AS COLD
AS FRIDAY NIGHT. COLDER MOUNTAIN VALLEYS WILL BOTTOM OUT BETWEEN
5 AND 15 BELOW. TEMPERATURES IN THE SOUTH WILL BE BETWEEN 5 ABOVE
AND 5 BELOW. EXPECT SOME HIGH CLOUDS TO FILTER IN FROM THE WEST
AFTER MIDNIGHT.

CLOUDS WILL BE ON THE INCREASE SUNDAY AS HIGH PRESSURE SHIFTS EAST
AND A COLD FRONT APPROACHES FROM THE WEST. HAVE GONE WITH LOW
CHANCE POPS FOR SOUTHWEST ZONES FOR LATE IN THE DAY BUT EXPECT ANY
SNOW SHOWERS TO BE LIGHT AND SPOTTY. HIGH TEMPS WILL CONTINUE
BELOW NORMAL WITH READINGS RANGING THROUGH THE 20S TO NEAR 30.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
500 MB PATTERN IN THE EXTENDED LOOKS TO REMAIN MOSTLY UNCHANGED
THROUGH THE EXTENDED ALTHOUGH STARTING TO SEE SOME SEASONAL
SHIFTING OF THE JET BACK TOWARD THE POLE. ALSO...SOME WEAKEN IN
BOTH THE UPSTREAM AND DOWNSTREAM BLOCKS WILL ALLOW FOR SOME MORE
COMPACT AND PROGRESSIVE WAVES TO DEVELOP WHICH SHOULD HELP
TRANSPORT SOME WARMER INTO THE NERN CONUS...AT LEAST FOR SHORT
PERIODS.

FIRST ON THE AGENDA IS THE FAST MOVING WAVE THAT SWINGS SE OUT OF
THE CANSDI9AN PRAIRIE AND THEN SHIFTS INTO NEW ENGLAND BEFORE
SHOWING A BIT OF A NEGATIVE TILT. LOOKS LIKE THE ENERGY GET S INTO
THE BASE OF THIS TROUGH TO LATE TO DEEPEN THE SFC LOW UNTIL IT IS
TO OUR EAST...AND SO WE WILL SOME SNOW LATE SUNDAY AND MAINLY
SUNDAY NIGHT. QPF LOOKS TO COME IN THE AROUND 0.20-0.25" FAIRLY
EVENLY ACROSS THE CWA...AND THIS SHOULD GENERALLY TRANSLATE TO
2-4" OF SNOW GIVEN SNOWFALL RATIOS OF ROUGHLY 10-15 TO 1. HIGHEST
AMTS LOOK TO BE IN THE SRN THIRD OF NH...WITH LOWEST AMTS IN
INTERIOR CENTRAL ME.  SNOW SHOULD WIND DOWN IN MOST PLACES BY
12Z...WITH WEST WINDS PICKING UP BY MIDDAY AND TEMPS RISING INTO
THE LOW-MID 30S NEAR THE COAST AND IN SRN NH...AND IN THE MID-
UPPER 30S IN THE NORTH. COLD AIR FILTERS IN MON NIGHT WITH LOWS
DROPPING BACK DOWN BETWEEN -5 AND +10 F. TUE WILL BE A LITTLE
COLDER AS LIGHT FLOW BECOMES MORE ONSHORE AND CLOUDS ROLL IN FROM
THE NEXT APPROACHING FROM THE SW.

THIS NEXT SYSTEM WILL FEATURE A 500MB CLOSED LOW WELL TO OUR NW
AND A FEW WEAK WAVES ROTATING AROUND IT AND GRADUALLY FLATTENING
OUT THE RIDGE UNTIL THE KICKER WAVE COME THRU ON THU. THIS WILL
KEEP THINGS UNSETTLED FROM TUE NIGHT INTO THE THU...ALTHOUGH THE
HIGHEST CONFIDENCE IN PRECIP OCCURRING FOR NOW TUE NIGHT INTO WED
MORNING. IT WILL START OUT AS SNOW...BUT IT WILL BE ACCOMPANIED BY
DECENT SW FLOW ALOFT...AND MAIN CHUNK OF HIGH SHIFTS OFF TO THE
EAST AND DOES NOT ENTRENCH ITSELF TO THE NE. THIS SHOULD ALLOW
THE WARN AIR TO MOVE IN FAIRLY CLOSE TO THE SFC. THE QUESTION IS
HOW LONG DOES THE COLD AIR DAM AT THE SFC HOLD ON...GIVEN THE DEEP
SNOWPACK. MODELS ARE PROBABLY OVERDOING THE WARM TO SOME DEGREE.
HAVE INCLUDED FZRA IN THE MIX ON WED. STILL SYSTEM IS FAIRLY
PROGRESSIVE AND QPFS GENERALLY LOOK TO BE IN THE HALF INCH
BALLPARK...SO NOT A BIG EVENT FOR NOW.

MODELS DO WANT TO STALL THE FRONT JUST TO OR S WED NIGHT INTO
THU...AND THEN DEVELOP A WAVE ALONG THE FRONT. FOR NOW MODELS
GENERALLY AGREE THAT MOST OF ANY PRECIP STAYS TO OUR S...BUT HAVE
KEPT THE CHC POPS IN THE FORECAST TO COVER THIS POSSIBILITY.
COLDER HIGH PRESSURE THEN BUILDS IN FOR FRI.

&&

.AVIATION /17Z SATURDAY THROUGH WEDNESDAY/...
SHORT TERM...VFR TODAY THROUGH TONIGHT. AREAS OF MVFR CIGS
DEVELOPING LATE SUNDAY.

LONG TERM...WILL LKLY SEE IFR CIGS/VIS IN SN FOR A GOOD CHUNK OF
SUN NIGHT AT ALL TERMINALS...BUT SHOULD SEE RAPID IMPROVEMENT OT
VFR FORM SW TO NE DURING MON MORNING /EXCEPT KHIE WHICH WILL SEE
OCCNL MVFR-IFR IN SHSN THRU MON AFTERNOON. VFR HOLDS MON NIGHT AND
TUE BEFORE ANOTHER SYSTEM MOVES IN TUE AND WILL PRODUCE FLIGHT
RESTRICTIONS LATE TUE NIGHT INTO WED.

&&

.MARINE...
SHORT TERM...FREEZING SPRAY ADVISORY THROUGH LATE MORNING.

LONG TERM...EXPECT TO NEED AN SCA MONDAY AFT INTO MON NIGHT IN W
FLOW. MAY NEED GALES FOR A PERIOD LATE MON AND MON
EVENING...BEFORE WINDS DIMINISH LATE MON NIGHT. SCA MAY BE NEEDED
AGAIN IN SW FLOW LATE TUE NIGH AND WED.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.

&&

$$




000
FXUS61 KBOX 281459
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
959 AM EST SAT FEB 28 2015

.SYNOPSIS...

A FAST MOVING LOW PRESSURE SYSTEM WILL BRING ACCUMULATING SNOW TO
THE REGION LATE SUNDAY INTO SUNDAY NIGHT...WITH THE HIGHEST AMOUNTS
EXPECTED SOUTH OF THE MASSACHUSETTS TURNPIKE AND AWAY FROM THE
IMMEDIATE SOUTH COAST. ANOTHER STORM IS LIKELY TUESDAY NIGHT INTO
WEDNESDAY...WITH SNOW AND MIXED PRECIPITATION LIKELY CHANGING TO
RAIN. COLD AND DRY CONDITIONS RETURN FOR THE END OF NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...

10 AM UPDATE...

NO MAJOR CHANGES. ONLY MODIFICATIONS TO TEMPERATURES AND
DEWPOINTS TO BRING THEM MORE IN-LINE WITH TRENDS.

PREVIOUS DISCUSSION...

HIGH PRESSURE OVERHEAD WILL ALLOW FOR SUNNY SKIES AND LIGHT WINDS.
TEMPERATURESS SHOULD RECOVER INTO THE MIDDLE TO UPPER 20S IN MOST
LOCATIONS...BUT THAT IS STILL AROUND 15 DEGREES BELOW NORMAL FOR
THE LAST DAY OF FEBRUARY. HOWEVER...THE INCREASING LATE FEBRUARY
SUN ANGLE AND LIGHT WINDS WILL MAKE IT SOMEWHAT MORE BEARABLE THAN
OUR RECENT COLD WAVES.

TONIGHT...

HIGH PRESSURE OVERHEAD WILL ALLOW FOR ANOTHER EXCELLENT NIGHT OF
RADIATIONAL COOLING.  THE NORMALLY COLDEST OUTLYING LOCATIONS WILL
DROP TO BETWEEN 5 AND 15 BELOW ZERO...WHILE MAINLY SINGLE DIGITS CAN
BE EXPECTED FOR THE REST OF THE REGION.  THE ONE FLY IN THE OINTMENT
IS WE ARE EXPECTING SOME MID/HIGH CLOUDS TO INCREASE FROM THE WEST
AFTER MIDNIGHT.  IF THEY COME IN A BIT EARLIER THEN EXPECTED OUR
TEMPERATURE FORECAST MIGHT BE TOO COLD.

&&

.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...

*** ACCUMULATING SNOW LATE SUNDAY AND ESPECIALLY SUNDAY NIGHT WITH
  THE HIGHEST AMOUNTS EXPECTED SOUTH OF THE MA TURNPIKE AND AWAY
  FROM THE IMMEDIATE SOUTH COAST ***

A DIGGING SHORTWAVE WILL DROP TOWARDS THE GREAT LAKES ON SUNDAY.
THIS WILL ALLOW FOR AN OVERRUNNING SETUP ACROSS SOUTHERN NEW
ENGLAND. A NICE FRONTOGENESIS SIGNATURE WITH A DEVELOPING LOW
LEVEL JET SHOULD RESULT IN A GOOD SLUG OF PRECIPITATION SUNDAY
EVENING INTO SUNDAY NIGHT. MOST MODELS ARE SHOWING A WEAK
SECONDARY LOW PRESSURE DEVELOPING NEAR THE SOUTH COAST. THIS WILL
HELP TO BACK AND STRENGTHEN THE LOW LEVEL JET ALONG WITH SOME
SURFACE CONVERGENCE RESULTING IN THE RISK FOR SOME HIGH
PRECIPITATION TOTALS SOUTH OF THE MA TURNPIKE WHICH WILL EXPLAIN
MORE BELOW.

1} TIMING AND PTYPE:

DRY WEATHER SHOULD PREVAIL SUNDAY MORNING. MID LEVEL WARM
ADVECTION SHOULD ALLOW LIGHT SNOW TO DEVELOP DURING THE AFTERNOON
ACROSS THE INTERIOR...REACHING THE COASTAL PLAIN BY LATE
AFTERNOON/EARLY EVENING. THE SNOW WILL INITIALLY BE LIGHT...BUT
EXPECT THE SNOW TO PICKUP IN INTENSITY SUNDAY EVENING AND
OVERNIGHT AS THE LOW LEVEL JET/FORCING INCREASE. MODEL SOUNDINGS
SHOW A PERIOD OF DECENT OMEGA IN THE PRIME SNOW GROWTH REGION.
SYSTEM IS FAIRLY PROGRESSIVE...SO THE SNOW SHOULD BE OVER EARLY
MONDAY MORNING AND BEFORE RUSH HOUR STARTS.

PTYPE WILL PROBABLY BE ALL SNOW FOR A LOT OF THE REGION. IT BECOMES
MORE UNCERTAIN ACROSS SOUTHERN RI AND FAR SOUTHEAST MA. THE NAM
MODEL IS AN OUTLIER AND MOST AGGRESSIVE IN BRINGING A SURGE OF
WARM MID LEVEL AIR NORTHWARD...WHICH WOULD CHANGE PTYPE TO RAIN
FOR JUST ABOUT ALL OF RHODE ISLAND AND SOUTHEAST MA SUN NIGHT.
HOWEVER...MOST OF THE OTHER GUIDANCE KEEPS PTYPE SNOW EXCEPT FOR
AREAS NEAR THE SOUTH COAST/CAPE/ISLANDS. SO FOR NOW WILL KEEP THE
CHANGE OVER LINE JUST SOUTH OF THE TAUNTON TO PROVIDENCE
CORRIDOR...BUT THIS MAY NEED TO BE ADJUSTED BASED ON LATEST MODEL
DATA.

2)SNOW ACCUMULATIONS AND HEADLINES:

THIS LOOKS TO BE A HIGH END WINTER WEATHER ADVISORY OR LOW END
WARNING FOR MUCH OF THE REGION. WE ARE GENERALLY EXPECTING
SNOWFALL AMOUNTS OF BETWEEN 3 AND 7 INCHES...AWAY FROM THE SOUTH
COAST WHERE PTYPE ISSUES WILL BE MORE PROBLEMATIC. THE NAM IS
HEAVIER ON QPF AND WE OPTED TO GO WITH A GFS/ECMWF BLEND. EVEN
THESE MODELS STILL HAVE BETWEEN 0.40 TO 0.60 INCHES OF PRECIP FROM
NEAR THE PIKE TO THE SOUTH COAST. THIS SEEMS TO BE IN RESPONSE TO
A WEAK WAVE DEVELOPING NEAR THE SOUTH COAST...ALLOWING FOR A MORE
BACKED LOW LEVEL JET AND BETTER SURFACE CONVERGENCE. WITH PRETTY
GOOD OMEGA IN THE SNOW GROWTH REGION...SNOWFALL RATIOS MAY BE
BETTER THAN 10 TO 1 RATIOS.

WITH THAT SAID...FELT IT IS WORTH A WINTER STORM WATCH FROM NEAR THE
PIKE TO AREAS INLAND FROM THE SOUTH COAST...WHERE PTYPE WILL
PROBABLY END UP AS MAINLY SNOW.  THIS IS FOR THE POTENTIAL OF 4 TO 7
INCHES OF SNOW. WE ARE FAIRLY CONFIDENCE IN WIDESPREAD 3 TO 4
INCH AMOUNTS...BUT CONFIDENCE IS LOWER ON WHETHER OR NOT WE SEE
THE 6 TO 7 INCH AMOUNTS. HOWEVER...WE ONLY NEED 50 PERCENT
CONFIDENCE IN THOSE HIGHER TOTALS OCCURRING TO ISSUE THE WATCH AND
IT GIVES THE NEXT SHIFT SOME MORE OPTIONS.

3) FORECAST UNCERTAINTY:

HOW MUCH SNOW WE ACTUALLY RECEIVE WILL HAVE A LOT TO DO WITH HOW
QUICKLY THE SECONDARY WAVE OF LOW PRESSURE DEVELOPS AND HOW FAR
NORTH THE RAIN/SNOW LINE GETS. THE NAM MODEL IS STRONGEST WITH
THE DEVELOPMENT OF THIS WAVE AND HENCE HAS THE HIGHEST QPF...BUT
DOES INTRODUCE MORE PTYPE ISSUES. MEANWHILE...THE GGEM IS THE
WEAKEST WITH THIS DEVELOPMENT AND BARELY HAS ADVISORY LEVEL SNOW
FOR THE REGION. CURRENTLY WE ARE LEANING TOWARDS A GFS/ECMWF
COMPROMISE...RESULTING IN 3 TO 7 INCHES OF SNOW WITH THE HIGHEST
AMOUNTS SOUTH OF PIKE AND AWAY FROM THE SOUTH COAST.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...

HIGHLIGHTS...

*  CONDITIONS IMPROVE MONDAY
*  ANOTHER STORM POSSIBLE TUE NIGHT INTO WED...WITH SNOW OR
   MIXED PRECIP LIKELY CHANGING TO RAIN
*  COLD AND DRY TOWARD THE END OF THE WEEK

OVERVIEW AND MODEL PREFERENCES...

ONE THING IS FOR CERTAIN...WITH LITTLE CHANGE IN THE NAO/AO AND
THE PNA EXPECTED TO REBOUND FROM NEGATIVE VALUES BACK TOWARD A
MORE NEUTRAL SOLUTION...THE COLD AIR AND LONGWAVE TROF LOOK TO
REMAIN THROUGH THE LONG TERM FORECAST. THE ONLY CAVEAT WILL BE IN
THE LOW LVLS ON WED...WHEN A ROBUST SW LLJ WILL ALLOW LOW-MID LVL
TEMPS TO WARM CLOSER TO ABOVE CLIMATOLOGICAL NORMALS. HOWEVER...
THE COLD AIR INITIALLY IN PLACE WILL LEAD TO P-TYPE ISSUES FOR THE
MID WEEK SYSTEM. ECMWF DETERMINISTIC REMAINS THE MOST ROBUST OF
THE OPERATIONAL MODELS...WITH HIGHER AMPLIFICATION IN THE FLOW
PATTERN THAN THE GFS AND UKMET. IT STARTS MUCH COLDER...BUT ENDS
MUCH WARMER. HOWEVER...DO NOTE THAT SOME OF THE GEFS AND ECENS
ENSEMBLES AGREE WITH THE ECMWF. THEREFORE...WILL BE USING THE
ENSEMBLE BLEND AS A BASELINE AS THIS TAKES INTO ACCOUNT BOTH THE
MORE PROGRESSIVE /AND ULTIMATELY LESS ROBUST WITH THE THERMAL
DIFFERENCES/ AND THE POTENTIAL FOR A MORE DYNAMIC SYSTEM. WILL USE
THIS BLEND THROUGH THE REMAINDER OF THE FORECAST AS WELL.

DETAILS...

MONDAY...

MORNING SNOWS COME TO AN END EARLY ACROSS E MA...AND FLURRIES
DISSIPATE THROUGH THE BERKSHIRES AND LITCHFIELD HILLS AS DRY NW
FLOW MOVES IN. BLUSTERY CONDITIONS EXPECTED...AND EVEN THROUGH
HIGHS WILL STILL BE MAKING IT INTO THE LOW-UPPER 30S...NW WINDS
WITH GUSTS 25-35 MPH AT TIMES WILL YIELD WIND CHILLS STRUGGLING
INTO THE LOW 20S.

MONDAY NIGHT INTO TUESDAY...

HIGH PRES WILL MOVE ACROSS THE REGION. DRY CONDITIONS DOMINATE
ALTHOUGH WITH TEMPS REMAINING BELOW NORMAL.

TUESDAY NIGHT INTO THURSDAY...

MODEL CONSENSUS IS NOW GENERALLY IN AGREEMENT THAT BOTH THE NRN
AND SRN STREAMS PHASE IN SOME FASHION ACROSS THE CENTRAL CONUS
WITH THE FORMATION OF LOW PRES WHICH IS EXPECTED TO SLIDE ACROSS
SRN CANADA. WARM FRONT WILL APPROACH...BUT GIVEN DEEP SNOWPACK THE
LOW LVL FRONT MAY ACTUAL STALL NEAR THE S COAST AS THE LOW MOVES
OVER AS THE UPPER WARM FRONT SLIDES INTO CENTRAL NEW ENGLAND. THIS
PRESENTS A GOOD OVERRUNNING SITUATION WITH STRONG 50-60 KT H92 LLJ
OUT OF THE SW. GIVEN THAT THIS SYSTEM IS ASSOCIATED WITH THE SRN
STREAM...IT ALSO CARRIES WITH IT A FAIR AMOUNT OF MOISTURE AS
PWATS LOOK TO REACH 2-3 STD DEVIATIONS ABOVE NORMAL

SO ALL IN ALL..PLENTY OF INGREDIENTS FOR HEAVY PRECIP ACROSS THE
AREA. THE QUESTION WILL BE TYPE...ALL GUIDANCE BEGIN COLD ENOUGH
FOR SNOW AT ONSET TUE NIGHT INTO EARLY WED. ECMWF WOULD SUGGEST
MUCH MORE AND BETTER LIFT IN THE SNOW GROWTH REGION...SO THERE IS
THAT TO CONSIDER. IN ANY CASE...WILL NEED TO AT LEAST WATCH FOR
POTENTIAL WARNING LEVEL SNOWFALL BEFORE THE WARM AIR BEGINS TO
BUILD IN FROM S TO N THROUGH THE DAY ON WED. EVEN THOUGH THE ECMWF
STARTS THE COLDEST...IT ENDS AS THE WARMEST SOLUTION...BRINGING
THE H92 +8C LINE ALL THE WAY INTO CENTRAL MA. SO WE DO EXPECT A
GRADUAL SHIFT TO A WINTRY MIX INCLUDING SLEET AND FREEZING RAIN
FOR A TIME GIVEN THE DEEP SNOWPACK ACROSS THE REGION. SOME AREAS
OF WRN MA...AND THE HILLS OF NRN CT MAY ACTUALLY STAY AS A MIX OF
SLEET FREEZING RAIN AND EVEN MAYBE SOME SNOW GIVEN THAT THE SFC
WARM FRONT MAY STALL. WILL HAVE TO WATCH FOR ICY CONDITIONS WITH
AS MUCH AS A QUARTER INCH OF ICE NOT OUT OF THE QUESTION WHERE IT
DOESN/T SWITCH TO RAIN WITH MELTING /BEST CHANCE OF RAIN/MELT IS
IN RI/CT AND PORTIONS OF MASS E OF I-495 AND S OF THE MASS PIKE/.
HEAVY RAIN A THREAT TOO GIVEN UPPER LVL INSTABILITY AND ROBUST
LLJ...SO WHERE MELTING AND HEAVY RAIN ARE OBSERVED...POOR DRAINAGE
FLOODING IS A POSSIBILITY WHERE SNOW CLOGS AREA DRAINS.

THIS HEAVY MIXED PRECIP EVENT COULD LINGER INTO THU...THE MORE
AMPLIFIED ECMWF AND SEVERAL ECENS/GEFS MEMBERS SUGGEST THAT THE
LEFTOVER COLD FRONT STALLS WITH YET ANOTHER WEAK WAVE OF LOW PRES
MOVING THROUGH THU. OTHER SOLUTIONS ARE MORE PROGRESSIVE AND HAVE
LESS QPF /SNOW POTENTIALLY/ ON THE BACK END. HOWEVER...BY THU
AFTERNOON/EVENING...CONDITIONS SHOULD BE IMPROVING /ALTHOUGH WITH
RAPID TEMPERATURE DROP/.

LATE NEXT WEEK...

EVEN THOUGH THERE IS UNCERTAINTY WITH HOW AMPLIFIED THE PATTERN
IS BY LATE WEEK. IT APPEARS A PERIOD OF DRY BUT COLD WX IS LIKELY
AS ARCTIC AIR ONCE AGAIN SHIFTS IN BEHIND THE EXITING MID WEEK
SYSTEM.

&&

.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...

FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TODAY THROUGH SUNDAY NIGHT/...

15Z UPDATE...NO CHANGES.

TODAY AND TONIGHT...HIGH CONFIDENCE. VFR.

SUNDAY MORNING...MODERATE CONFIDENCE. VFR. INCREASING MID-LEVEL
CLOUDS.

SUNDAY AFTERNOON INTO MONDAY MORNING...

SNOW OVERSPREADS THE REGION W-E. CIGS/VSBYS DETERIORATE TO MVFR-
IFR BY EARLY EVENING...WIDESPREAD IFR-LIFR SUNDAY NIGHT. SN MAY
MIX WITH OR CHANGE TO RA FOR A TIME ACROSS PORTIONS OF S RI AND
FAR SE MA...ESPECIALLY IMMEDIATE S-COAST/CAPE AND ISLANDS. PRECIP
SHOULD RAPIDLY END FROM W-E TOWARD DAYBREAK MONDAY....IMPROVING
CONDITIONS.

KBOS TAF...HIGH CONFIDENCE. VFR INTO SUNDAY MORNING.

KBDL TAF...HIGH CONFIDENCE. VFR INTO SUNDAY MORNING.

OUTLOOK...MONDAY THROUGH WEDNESDAY...

MONDAY...HIGH CONFIDENCE.

CONDITIONS IMPROVE EARLY FROM IFR/MVFR IN SNOWS AND LOW CIGS...
WITH VFR EXPECTED EVERYWHERE BY AFTERNOON. NW WINDS IN THE
AFTERNOON WITH GUSTS 25-30 KT.

MON NIGHT INTO TUE...HIGH CONFIDENCE.

MAINLY VFR. GRADUALLY LOWERING CIGS ON TUE.

TUE NIGHT INTO WED...MODERATE CONFIDENCE.

MIXED WINTRY PRECIP LIKELY STARTS AS ALL SNOW...TRANSITIONS TO A
MIX OF SLEET AND FREEZING RAIN...THEN TO ALL RAIN DURING THE DAY
ON WED. SOME SNOW AND ICE ACCUMULATIONS ARE LIKELY WITH IFR OR
POTENTIALLY EVEN LIFR CONDITIONS AT TIMES.

&&

.MARINE...

FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /THROUGH SATURDAY NIGHT/...HIGH CONFIDENCE.

10 AM UPDATE...NO MAJOR CHANGES.

HIGH PRESSURE NEARBY WILL KEEP WINDS/SEAS WELL BELOW SMALL CRAFT
ADVISORY THRESHOLDS INTO SUNDAY MORNING. A WEAK WAVE OF LOW
PRESSURE MOVES ACROSS THE WATERS LATE SUN INTO SUN NIGHT...BUT
WEAK PRESSURE GRADIENT SHOULD KEEP WINDS/SEAS BELOW SMALL CRAFT
THRESHOLDS.

OUTLOOK...SUNDAY THROUGH WEDNESDAY...

MONDAY INTO MONDAY NIGHT...HIGH CONFIDENCE.

SW WINDS SHIFT TO THE NW DURING THE DAYLIGHT HOURS AS A COLD
FRONT SWEEPS ACROSS THE WATERS. ONCE WINDS SHIFT NW IN THE
AFTERNOON EXPECT GALE FORCE GUSTS 35-40KT. COLDER AIR TUE NIGHT
COULD LEAD TO LIGHT FREEZING SPRAY.

TUESDAY...MODERATE CONFIDENCE.

WINDS GRADUALLY DIMINISH OUT OF THE W-NW BUT SEAS ARE LIKELY TO
REMAIN ELEVATED 5-8FT ON THE OCEAN WATERS. SMALL CRAFT ADVISORIES
WILL LIKELY BE NEEDED.

TUESDAY NIGHT INTO WEDNESDAY...MODERATE CONFIDENCE.

SNOW CHANGES TO RAIN TUE NIGHT WITH LOW VSBYS OVER THE WATERS.
WINDS OUT OF THE S MAINLY AROUND 25-30 KT AT MOST. SEAS BUILD
12-15 FT BY DAYTIME ON WED ON SE OCEAN WATERS. SMALL CRAFT
ADVISORIES WILL LIKELY BE NEEDED.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...

CT...WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH LATE SUNDAY
     NIGHT FOR CTZ002>004.
MA...WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH LATE SUNDAY
     NIGHT FOR MAZ009-011>013-015>019.
RI...WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH LATE SUNDAY
     NIGHT FOR RIZ001>004.
MARINE...NONE.
LEFT OVER SMALL CRAFT SEAS ACROSS THE OUTER-WATERS WILL DIMINISH
EARLY THIS MORNING.  OTHERWISE...
&&

$$

SYNOPSIS...FRANK/DOODY
NEAR TERM...FRANK/DOODY/SIPPRELL
SHORT TERM...FRANK
LONG TERM...DOODY
AVIATION...FRANK/DOODY/SIPPRELL
MARINE...FRANK/DOODY



000
FXUS61 KBOX 281459
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
959 AM EST SAT FEB 28 2015

.SYNOPSIS...

A FAST MOVING LOW PRESSURE SYSTEM WILL BRING ACCUMULATING SNOW TO
THE REGION LATE SUNDAY INTO SUNDAY NIGHT...WITH THE HIGHEST AMOUNTS
EXPECTED SOUTH OF THE MASSACHUSETTS TURNPIKE AND AWAY FROM THE
IMMEDIATE SOUTH COAST. ANOTHER STORM IS LIKELY TUESDAY NIGHT INTO
WEDNESDAY...WITH SNOW AND MIXED PRECIPITATION LIKELY CHANGING TO
RAIN. COLD AND DRY CONDITIONS RETURN FOR THE END OF NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...

10 AM UPDATE...

NO MAJOR CHANGES. ONLY MODIFICATIONS TO TEMPERATURES AND
DEWPOINTS TO BRING THEM MORE IN-LINE WITH TRENDS.

PREVIOUS DISCUSSION...

HIGH PRESSURE OVERHEAD WILL ALLOW FOR SUNNY SKIES AND LIGHT WINDS.
TEMPERATURESS SHOULD RECOVER INTO THE MIDDLE TO UPPER 20S IN MOST
LOCATIONS...BUT THAT IS STILL AROUND 15 DEGREES BELOW NORMAL FOR
THE LAST DAY OF FEBRUARY. HOWEVER...THE INCREASING LATE FEBRUARY
SUN ANGLE AND LIGHT WINDS WILL MAKE IT SOMEWHAT MORE BEARABLE THAN
OUR RECENT COLD WAVES.

TONIGHT...

HIGH PRESSURE OVERHEAD WILL ALLOW FOR ANOTHER EXCELLENT NIGHT OF
RADIATIONAL COOLING.  THE NORMALLY COLDEST OUTLYING LOCATIONS WILL
DROP TO BETWEEN 5 AND 15 BELOW ZERO...WHILE MAINLY SINGLE DIGITS CAN
BE EXPECTED FOR THE REST OF THE REGION.  THE ONE FLY IN THE OINTMENT
IS WE ARE EXPECTING SOME MID/HIGH CLOUDS TO INCREASE FROM THE WEST
AFTER MIDNIGHT.  IF THEY COME IN A BIT EARLIER THEN EXPECTED OUR
TEMPERATURE FORECAST MIGHT BE TOO COLD.

&&

.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...

*** ACCUMULATING SNOW LATE SUNDAY AND ESPECIALLY SUNDAY NIGHT WITH
  THE HIGHEST AMOUNTS EXPECTED SOUTH OF THE MA TURNPIKE AND AWAY
  FROM THE IMMEDIATE SOUTH COAST ***

A DIGGING SHORTWAVE WILL DROP TOWARDS THE GREAT LAKES ON SUNDAY.
THIS WILL ALLOW FOR AN OVERRUNNING SETUP ACROSS SOUTHERN NEW
ENGLAND. A NICE FRONTOGENESIS SIGNATURE WITH A DEVELOPING LOW
LEVEL JET SHOULD RESULT IN A GOOD SLUG OF PRECIPITATION SUNDAY
EVENING INTO SUNDAY NIGHT. MOST MODELS ARE SHOWING A WEAK
SECONDARY LOW PRESSURE DEVELOPING NEAR THE SOUTH COAST. THIS WILL
HELP TO BACK AND STRENGTHEN THE LOW LEVEL JET ALONG WITH SOME
SURFACE CONVERGENCE RESULTING IN THE RISK FOR SOME HIGH
PRECIPITATION TOTALS SOUTH OF THE MA TURNPIKE WHICH WILL EXPLAIN
MORE BELOW.

1} TIMING AND PTYPE:

DRY WEATHER SHOULD PREVAIL SUNDAY MORNING. MID LEVEL WARM
ADVECTION SHOULD ALLOW LIGHT SNOW TO DEVELOP DURING THE AFTERNOON
ACROSS THE INTERIOR...REACHING THE COASTAL PLAIN BY LATE
AFTERNOON/EARLY EVENING. THE SNOW WILL INITIALLY BE LIGHT...BUT
EXPECT THE SNOW TO PICKUP IN INTENSITY SUNDAY EVENING AND
OVERNIGHT AS THE LOW LEVEL JET/FORCING INCREASE. MODEL SOUNDINGS
SHOW A PERIOD OF DECENT OMEGA IN THE PRIME SNOW GROWTH REGION.
SYSTEM IS FAIRLY PROGRESSIVE...SO THE SNOW SHOULD BE OVER EARLY
MONDAY MORNING AND BEFORE RUSH HOUR STARTS.

PTYPE WILL PROBABLY BE ALL SNOW FOR A LOT OF THE REGION. IT BECOMES
MORE UNCERTAIN ACROSS SOUTHERN RI AND FAR SOUTHEAST MA. THE NAM
MODEL IS AN OUTLIER AND MOST AGGRESSIVE IN BRINGING A SURGE OF
WARM MID LEVEL AIR NORTHWARD...WHICH WOULD CHANGE PTYPE TO RAIN
FOR JUST ABOUT ALL OF RHODE ISLAND AND SOUTHEAST MA SUN NIGHT.
HOWEVER...MOST OF THE OTHER GUIDANCE KEEPS PTYPE SNOW EXCEPT FOR
AREAS NEAR THE SOUTH COAST/CAPE/ISLANDS. SO FOR NOW WILL KEEP THE
CHANGE OVER LINE JUST SOUTH OF THE TAUNTON TO PROVIDENCE
CORRIDOR...BUT THIS MAY NEED TO BE ADJUSTED BASED ON LATEST MODEL
DATA.

2)SNOW ACCUMULATIONS AND HEADLINES:

THIS LOOKS TO BE A HIGH END WINTER WEATHER ADVISORY OR LOW END
WARNING FOR MUCH OF THE REGION. WE ARE GENERALLY EXPECTING
SNOWFALL AMOUNTS OF BETWEEN 3 AND 7 INCHES...AWAY FROM THE SOUTH
COAST WHERE PTYPE ISSUES WILL BE MORE PROBLEMATIC. THE NAM IS
HEAVIER ON QPF AND WE OPTED TO GO WITH A GFS/ECMWF BLEND. EVEN
THESE MODELS STILL HAVE BETWEEN 0.40 TO 0.60 INCHES OF PRECIP FROM
NEAR THE PIKE TO THE SOUTH COAST. THIS SEEMS TO BE IN RESPONSE TO
A WEAK WAVE DEVELOPING NEAR THE SOUTH COAST...ALLOWING FOR A MORE
BACKED LOW LEVEL JET AND BETTER SURFACE CONVERGENCE. WITH PRETTY
GOOD OMEGA IN THE SNOW GROWTH REGION...SNOWFALL RATIOS MAY BE
BETTER THAN 10 TO 1 RATIOS.

WITH THAT SAID...FELT IT IS WORTH A WINTER STORM WATCH FROM NEAR THE
PIKE TO AREAS INLAND FROM THE SOUTH COAST...WHERE PTYPE WILL
PROBABLY END UP AS MAINLY SNOW.  THIS IS FOR THE POTENTIAL OF 4 TO 7
INCHES OF SNOW. WE ARE FAIRLY CONFIDENCE IN WIDESPREAD 3 TO 4
INCH AMOUNTS...BUT CONFIDENCE IS LOWER ON WHETHER OR NOT WE SEE
THE 6 TO 7 INCH AMOUNTS. HOWEVER...WE ONLY NEED 50 PERCENT
CONFIDENCE IN THOSE HIGHER TOTALS OCCURRING TO ISSUE THE WATCH AND
IT GIVES THE NEXT SHIFT SOME MORE OPTIONS.

3) FORECAST UNCERTAINTY:

HOW MUCH SNOW WE ACTUALLY RECEIVE WILL HAVE A LOT TO DO WITH HOW
QUICKLY THE SECONDARY WAVE OF LOW PRESSURE DEVELOPS AND HOW FAR
NORTH THE RAIN/SNOW LINE GETS. THE NAM MODEL IS STRONGEST WITH
THE DEVELOPMENT OF THIS WAVE AND HENCE HAS THE HIGHEST QPF...BUT
DOES INTRODUCE MORE PTYPE ISSUES. MEANWHILE...THE GGEM IS THE
WEAKEST WITH THIS DEVELOPMENT AND BARELY HAS ADVISORY LEVEL SNOW
FOR THE REGION. CURRENTLY WE ARE LEANING TOWARDS A GFS/ECMWF
COMPROMISE...RESULTING IN 3 TO 7 INCHES OF SNOW WITH THE HIGHEST
AMOUNTS SOUTH OF PIKE AND AWAY FROM THE SOUTH COAST.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...

HIGHLIGHTS...

*  CONDITIONS IMPROVE MONDAY
*  ANOTHER STORM POSSIBLE TUE NIGHT INTO WED...WITH SNOW OR
   MIXED PRECIP LIKELY CHANGING TO RAIN
*  COLD AND DRY TOWARD THE END OF THE WEEK

OVERVIEW AND MODEL PREFERENCES...

ONE THING IS FOR CERTAIN...WITH LITTLE CHANGE IN THE NAO/AO AND
THE PNA EXPECTED TO REBOUND FROM NEGATIVE VALUES BACK TOWARD A
MORE NEUTRAL SOLUTION...THE COLD AIR AND LONGWAVE TROF LOOK TO
REMAIN THROUGH THE LONG TERM FORECAST. THE ONLY CAVEAT WILL BE IN
THE LOW LVLS ON WED...WHEN A ROBUST SW LLJ WILL ALLOW LOW-MID LVL
TEMPS TO WARM CLOSER TO ABOVE CLIMATOLOGICAL NORMALS. HOWEVER...
THE COLD AIR INITIALLY IN PLACE WILL LEAD TO P-TYPE ISSUES FOR THE
MID WEEK SYSTEM. ECMWF DETERMINISTIC REMAINS THE MOST ROBUST OF
THE OPERATIONAL MODELS...WITH HIGHER AMPLIFICATION IN THE FLOW
PATTERN THAN THE GFS AND UKMET. IT STARTS MUCH COLDER...BUT ENDS
MUCH WARMER. HOWEVER...DO NOTE THAT SOME OF THE GEFS AND ECENS
ENSEMBLES AGREE WITH THE ECMWF. THEREFORE...WILL BE USING THE
ENSEMBLE BLEND AS A BASELINE AS THIS TAKES INTO ACCOUNT BOTH THE
MORE PROGRESSIVE /AND ULTIMATELY LESS ROBUST WITH THE THERMAL
DIFFERENCES/ AND THE POTENTIAL FOR A MORE DYNAMIC SYSTEM. WILL USE
THIS BLEND THROUGH THE REMAINDER OF THE FORECAST AS WELL.

DETAILS...

MONDAY...

MORNING SNOWS COME TO AN END EARLY ACROSS E MA...AND FLURRIES
DISSIPATE THROUGH THE BERKSHIRES AND LITCHFIELD HILLS AS DRY NW
FLOW MOVES IN. BLUSTERY CONDITIONS EXPECTED...AND EVEN THROUGH
HIGHS WILL STILL BE MAKING IT INTO THE LOW-UPPER 30S...NW WINDS
WITH GUSTS 25-35 MPH AT TIMES WILL YIELD WIND CHILLS STRUGGLING
INTO THE LOW 20S.

MONDAY NIGHT INTO TUESDAY...

HIGH PRES WILL MOVE ACROSS THE REGION. DRY CONDITIONS DOMINATE
ALTHOUGH WITH TEMPS REMAINING BELOW NORMAL.

TUESDAY NIGHT INTO THURSDAY...

MODEL CONSENSUS IS NOW GENERALLY IN AGREEMENT THAT BOTH THE NRN
AND SRN STREAMS PHASE IN SOME FASHION ACROSS THE CENTRAL CONUS
WITH THE FORMATION OF LOW PRES WHICH IS EXPECTED TO SLIDE ACROSS
SRN CANADA. WARM FRONT WILL APPROACH...BUT GIVEN DEEP SNOWPACK THE
LOW LVL FRONT MAY ACTUAL STALL NEAR THE S COAST AS THE LOW MOVES
OVER AS THE UPPER WARM FRONT SLIDES INTO CENTRAL NEW ENGLAND. THIS
PRESENTS A GOOD OVERRUNNING SITUATION WITH STRONG 50-60 KT H92 LLJ
OUT OF THE SW. GIVEN THAT THIS SYSTEM IS ASSOCIATED WITH THE SRN
STREAM...IT ALSO CARRIES WITH IT A FAIR AMOUNT OF MOISTURE AS
PWATS LOOK TO REACH 2-3 STD DEVIATIONS ABOVE NORMAL

SO ALL IN ALL..PLENTY OF INGREDIENTS FOR HEAVY PRECIP ACROSS THE
AREA. THE QUESTION WILL BE TYPE...ALL GUIDANCE BEGIN COLD ENOUGH
FOR SNOW AT ONSET TUE NIGHT INTO EARLY WED. ECMWF WOULD SUGGEST
MUCH MORE AND BETTER LIFT IN THE SNOW GROWTH REGION...SO THERE IS
THAT TO CONSIDER. IN ANY CASE...WILL NEED TO AT LEAST WATCH FOR
POTENTIAL WARNING LEVEL SNOWFALL BEFORE THE WARM AIR BEGINS TO
BUILD IN FROM S TO N THROUGH THE DAY ON WED. EVEN THOUGH THE ECMWF
STARTS THE COLDEST...IT ENDS AS THE WARMEST SOLUTION...BRINGING
THE H92 +8C LINE ALL THE WAY INTO CENTRAL MA. SO WE DO EXPECT A
GRADUAL SHIFT TO A WINTRY MIX INCLUDING SLEET AND FREEZING RAIN
FOR A TIME GIVEN THE DEEP SNOWPACK ACROSS THE REGION. SOME AREAS
OF WRN MA...AND THE HILLS OF NRN CT MAY ACTUALLY STAY AS A MIX OF
SLEET FREEZING RAIN AND EVEN MAYBE SOME SNOW GIVEN THAT THE SFC
WARM FRONT MAY STALL. WILL HAVE TO WATCH FOR ICY CONDITIONS WITH
AS MUCH AS A QUARTER INCH OF ICE NOT OUT OF THE QUESTION WHERE IT
DOESN/T SWITCH TO RAIN WITH MELTING /BEST CHANCE OF RAIN/MELT IS
IN RI/CT AND PORTIONS OF MASS E OF I-495 AND S OF THE MASS PIKE/.
HEAVY RAIN A THREAT TOO GIVEN UPPER LVL INSTABILITY AND ROBUST
LLJ...SO WHERE MELTING AND HEAVY RAIN ARE OBSERVED...POOR DRAINAGE
FLOODING IS A POSSIBILITY WHERE SNOW CLOGS AREA DRAINS.

THIS HEAVY MIXED PRECIP EVENT COULD LINGER INTO THU...THE MORE
AMPLIFIED ECMWF AND SEVERAL ECENS/GEFS MEMBERS SUGGEST THAT THE
LEFTOVER COLD FRONT STALLS WITH YET ANOTHER WEAK WAVE OF LOW PRES
MOVING THROUGH THU. OTHER SOLUTIONS ARE MORE PROGRESSIVE AND HAVE
LESS QPF /SNOW POTENTIALLY/ ON THE BACK END. HOWEVER...BY THU
AFTERNOON/EVENING...CONDITIONS SHOULD BE IMPROVING /ALTHOUGH WITH
RAPID TEMPERATURE DROP/.

LATE NEXT WEEK...

EVEN THOUGH THERE IS UNCERTAINTY WITH HOW AMPLIFIED THE PATTERN
IS BY LATE WEEK. IT APPEARS A PERIOD OF DRY BUT COLD WX IS LIKELY
AS ARCTIC AIR ONCE AGAIN SHIFTS IN BEHIND THE EXITING MID WEEK
SYSTEM.

&&

.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...

FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TODAY THROUGH SUNDAY NIGHT/...

15Z UPDATE...NO CHANGES.

TODAY AND TONIGHT...HIGH CONFIDENCE. VFR.

SUNDAY MORNING...MODERATE CONFIDENCE. VFR. INCREASING MID-LEVEL
CLOUDS.

SUNDAY AFTERNOON INTO MONDAY MORNING...

SNOW OVERSPREADS THE REGION W-E. CIGS/VSBYS DETERIORATE TO MVFR-
IFR BY EARLY EVENING...WIDESPREAD IFR-LIFR SUNDAY NIGHT. SN MAY
MIX WITH OR CHANGE TO RA FOR A TIME ACROSS PORTIONS OF S RI AND
FAR SE MA...ESPECIALLY IMMEDIATE S-COAST/CAPE AND ISLANDS. PRECIP
SHOULD RAPIDLY END FROM W-E TOWARD DAYBREAK MONDAY....IMPROVING
CONDITIONS.

KBOS TAF...HIGH CONFIDENCE. VFR INTO SUNDAY MORNING.

KBDL TAF...HIGH CONFIDENCE. VFR INTO SUNDAY MORNING.

OUTLOOK...MONDAY THROUGH WEDNESDAY...

MONDAY...HIGH CONFIDENCE.

CONDITIONS IMPROVE EARLY FROM IFR/MVFR IN SNOWS AND LOW CIGS...
WITH VFR EXPECTED EVERYWHERE BY AFTERNOON. NW WINDS IN THE
AFTERNOON WITH GUSTS 25-30 KT.

MON NIGHT INTO TUE...HIGH CONFIDENCE.

MAINLY VFR. GRADUALLY LOWERING CIGS ON TUE.

TUE NIGHT INTO WED...MODERATE CONFIDENCE.

MIXED WINTRY PRECIP LIKELY STARTS AS ALL SNOW...TRANSITIONS TO A
MIX OF SLEET AND FREEZING RAIN...THEN TO ALL RAIN DURING THE DAY
ON WED. SOME SNOW AND ICE ACCUMULATIONS ARE LIKELY WITH IFR OR
POTENTIALLY EVEN LIFR CONDITIONS AT TIMES.

&&

.MARINE...

FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /THROUGH SATURDAY NIGHT/...HIGH CONFIDENCE.

10 AM UPDATE...NO MAJOR CHANGES.

HIGH PRESSURE NEARBY WILL KEEP WINDS/SEAS WELL BELOW SMALL CRAFT
ADVISORY THRESHOLDS INTO SUNDAY MORNING. A WEAK WAVE OF LOW
PRESSURE MOVES ACROSS THE WATERS LATE SUN INTO SUN NIGHT...BUT
WEAK PRESSURE GRADIENT SHOULD KEEP WINDS/SEAS BELOW SMALL CRAFT
THRESHOLDS.

OUTLOOK...SUNDAY THROUGH WEDNESDAY...

MONDAY INTO MONDAY NIGHT...HIGH CONFIDENCE.

SW WINDS SHIFT TO THE NW DURING THE DAYLIGHT HOURS AS A COLD
FRONT SWEEPS ACROSS THE WATERS. ONCE WINDS SHIFT NW IN THE
AFTERNOON EXPECT GALE FORCE GUSTS 35-40KT. COLDER AIR TUE NIGHT
COULD LEAD TO LIGHT FREEZING SPRAY.

TUESDAY...MODERATE CONFIDENCE.

WINDS GRADUALLY DIMINISH OUT OF THE W-NW BUT SEAS ARE LIKELY TO
REMAIN ELEVATED 5-8FT ON THE OCEAN WATERS. SMALL CRAFT ADVISORIES
WILL LIKELY BE NEEDED.

TUESDAY NIGHT INTO WEDNESDAY...MODERATE CONFIDENCE.

SNOW CHANGES TO RAIN TUE NIGHT WITH LOW VSBYS OVER THE WATERS.
WINDS OUT OF THE S MAINLY AROUND 25-30 KT AT MOST. SEAS BUILD
12-15 FT BY DAYTIME ON WED ON SE OCEAN WATERS. SMALL CRAFT
ADVISORIES WILL LIKELY BE NEEDED.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...

CT...WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH LATE SUNDAY
     NIGHT FOR CTZ002>004.
MA...WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH LATE SUNDAY
     NIGHT FOR MAZ009-011>013-015>019.
RI...WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH LATE SUNDAY
     NIGHT FOR RIZ001>004.
MARINE...NONE.
LEFT OVER SMALL CRAFT SEAS ACROSS THE OUTER-WATERS WILL DIMINISH
EARLY THIS MORNING.  OTHERWISE...
&&

$$

SYNOPSIS...FRANK/DOODY
NEAR TERM...FRANK/DOODY/SIPPRELL
SHORT TERM...FRANK
LONG TERM...DOODY
AVIATION...FRANK/DOODY/SIPPRELL
MARINE...FRANK/DOODY




000
FXUS61 KGYX 281434
AFDGYX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
934 AM EST SAT FEB 28 2015

.SYNOPSIS...
HIGH PRESSURE WILL BUILD OVER THE REGION TODAY AND WILL SHIFT
OFFSHORE SUNDAY. WEAK LOW PRESSURE CROSSES THE REGION SUNDAY
NIGHT...PRODUCING SOME ACCUMULATING SNOW...BEFORE MOVING INTO THE
CANADIAN MARITIMES ON MONDAY. HIGH PRESSURE CROSSES THE AREA
MONDAY NIGHT AND TUESDAY. LOW PRESSURE WILL MOVE OUT OF THE GREAT
LAKES TUESDAY NIGHT AND WILL TRACK NORTHEAST THROUGH THE ST
LAWRENCE VALLEY ON WEDNESDAY...BRINGING A ROUND OF MIXED
PRECIPITATION TO THE AREA. A COLD FRONT FOLLOWS WEDNESDAY NIGHT.
HIGH PRESSURE BUILDS IN FOR THE END OF THE WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
UPDATE...
HAVE UPDATED THE GRIDS BASED ON CURRENT TRENDS AND CONDITIONS. -7
DEGREES IN PORTLAND LAST NIGHT WAS VERY CLOSE TO THE ALL-TIME
RECORD LOW OF -9. EXPECT TO FORECAST BELOW MODEL GUIDANCE AGAIN
TONIGHT FOR THE MIN TEMPERATURES.

SUNNY FOR THE REST OF TODAY...WITH LIGHT WINDS. FREEZING SPRAY
ADVISORY WILL END SHORTLY.

PREV DISC...
HIGH PRESSURE WILL CONTINUE TO BUILD IN FROM THE WEST
TODAY PROVIDING SUNNY SKIES AND SLIGHTLY WARMER TEMPS. HIGHS WILL
RANGE FROM THE UPPER TEENS TO LOWER 20S NORTH AND MID TO UPPER 20S
SOUTH.

&&

.SHORT TERM /SUNDAY/...
HIGH PRESSURE WILL CREST OVER THE REGION TONIGHT. GOOD RADIATIONAL
COOLING WILL AGAIN SEND TEMPS WELL BELOW NORMAL BUT NOT QUITE AS COLD
AS FRIDAY NIGHT. COLDER MOUNTAIN VALLEYS WILL BOTTOM OUT BETWEEN
5 AND 15 BELOW. TEMPERATURES IN THE SOUTH WILL BE BETWEEN 5 ABOVE
AND 5 BELOW. EXPECT SOME HIGH CLOUDS TO FILTER IN FROM THE WEST
AFTER MIDNIGHT.

CLOUDS WILL BE ON THE INCREASE SUNDAY AS HIGH PRESSURE SHIFTS EAST
AND A COLD FRONT APPROACHES FROM THE WEST. HAVE GONE WITH LOW
CHANCE POPS FOR SOUTHWEST ZONES FOR LATE IN THE DAY BUT EXPECT ANY
SNOW SHOWERS TO BE LIGHT AND SPOTTY. HIGH TEMPS WILL CONTINUE
BELOW NORMAL WITH READINGS RANGING THROUGH THE 20S TO NEAR 30.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
500 MB PATTERN IN THE EXTENDED LOOKS TO REMAIN MOSTLY UNCHANGED
THROUGH THE EXTENDED ALTHOUGH STARTING TO SEE SOME SEASONAL
SHIFTING OF THE JET BACK TOWARD THE POLE. ALSO...SOME WEAKEN IN
BOTH THE UPSTREAM AND DOWNSTREAM BLOCKS WILL ALLOW FOR SOME MORE
COMPACT AND PROGRESSIVE WAVES TO DEVELOP WHICH SHOULD HELP
TRANSPORT SOME WARMER INTO THE NERN CONUS...AT LEAST FOR SHORT
PERIODS.

FIRST ON THE AGENDA IS THE FAST MOVING WAVE THAT SWINGS SE OUT OF
THE CANSDI9AN PRAIRIE AND THEN SHIFTS INTO NEW ENGLAND BEFORE
SHOWING A BIT OF A NEGATIVE TILT. LOOKS LIKE THE ENERGY GET S INTO
THE BASE OF THIS TROUGH TO LATE TO DEEPEN THE SFC LOW UNTIL IT IS
TO OUR EAST...AND SO WE WILL SOME SNOW LATE SUNDAY AND MAINLY
SUNDAY NIGHT. QPF LOOKS TO COME IN THE AROUND 0.20-0.25" FAIRLY
EVENLY ACROSS THE CWA...AND THIS SHOULD GENERALLY TRANSLATE TO
2-4" OF SNOW GIVEN SNOWFALL RATIOS OF ROUGHLY 10-15 TO 1. HIGHEST
AMTS LOOK TO BE IN THE SRN THIRD OF NH...WITH LOWEST AMTS IN
INTERIOR CENTRAL ME.  SNOW SHOULD WIND DOWN IN MOST PLACES BY
12Z...WITH WEST WINDS PICKING UP BY MIDDAY AND TEMPS RISING INTO
THE LOW-MID 30S NEAR THE COAST AND IN SRN NH...AND IN THE MID-
UPPER 30S IN THE NORTH. COLD AIR FILTERS IN MON NIGHT WITH LOWS
DROPPING BACK DOWN BETWEEN -5 AND +10 F. TUE WILL BE A LITTLE
COLDER AS LIGHT FLOW BECOMES MORE ONSHORE AND CLOUDS ROLL IN FROM
THE NEXT APPROACHING FROM THE SW.

THIS NEXT SYSTEM WILL FEATURE A 500MB CLOSED LOW WELL TO OUR NW
AND A FEW WEAK WAVES ROTATING AROUND IT AND GRADUALLY FLATTENING
OUT THE RIDGE UNTIL THE KICKER WAVE COME THRU ON THU. THIS WILL
KEEP THINGS UNSETTLED FROM TUE NIGHT INTO THE THU...ALTHOUGH THE
HIGHEST CONFIDENCE IN PRECIP OCCURRING FOR NOW TUE NIGHT INTO WED
MORNING. IT WILL START OUT AS SNOW...BUT IT WILL BE ACCOMPANIED BY
DECENT SW FLOW ALOFT...AND MAIN CHUNK OF HIGH SHIFTS OFF TO THE
EAST AND DOES NOT ENTRENCH ITSELF TO THE NE. THIS SHOULD ALLOW
THE WARN AIR TO MOVE IN FAIRLY CLOSE TO THE SFC. THE QUESTION IS
HOW LONG DOES THE COLD AIR DAM AT THE SFC HOLD ON...GIVEN THE DEEP
SNOWPACK. MODELS ARE PROBABLY OVERDOING THE WARM TO SOME DEGREE.
HAVE INCLUDED FZRA IN THE MIX ON WED. STILL SYSTEM IS FAIRLY
PROGRESSIVE AND QPFS GENERALLY LOOK TO BE IN THE HALF INCH
BALLPARK...SO NOT A BIG EVENT FOR NOW.

MODELS DO WANT TO STALL THE FRONT JUST TO OR S WED NIGHT INTO
THU...AND THEN DEVELOP A WAVE ALONG THE FRONT. FOR NOW MODELS
GENERALLY AGREE THAT MOST OF ANY PRECIP STAYS TO OUR S...BUT HAVE
KEPT THE CHC POPS IN THE FORECAST TO COVER THIS POSSIBILITY.
COLDER HIGH PRESSURE THEN BUILDS IN FOR FRI.

&&

.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
SHORT TERM...VFR TODAY THROUGH TONIGHT. AREAS OF MVFR CIGS
DEVELOPING LATE SUNDAY.

LONG TERM...WILL LKLY SEE IFR CIGS/VIS IN SN FOR A GOOD CHUNK OF
SUN NIGHT AT ALL TERMINALS...BUT SHOULD SEE RAPID IMPROVEMENT OT
VFR FORM SW TO NE DURING MON MORNING /EXCEPT KHIE WHICH WILL SEE
OCCNL MVFR-IFR IN SHSN THRU MON AFTERNOON. VFR HOLDS MON NIGHT AND
TUE BEFORE ANOTHER SYSTEM MOVES IN TUE AND WILL PRODUCE FLIGHT
RESTRICTIONS LATE TUE NIGHT INTO WED.

&&

.MARINE...
SHORT TERM...FREEZING SPRAY ADVISORY THROUGH LATE MORNING.

LONG TERM...EXPECT TO NEED AN SCA MONDAY AFT INTO MON NIGHT IN W
FLOW. MAY NEED GALES FOR A PERIOD LATE MON AND MON
EVENING...BEFORE WINDS DIMINISH LATE MON NIGHT. SCA MAY BE NEEDED
AGAIN IN SW FLOW LATE TUE NIGH AND WED.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...FREEZING SPRAY ADVISORY UNTIL NOON EST TODAY FOR ANZ150>152.

&&

$$



000
FXUS61 KGYX 281434
AFDGYX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
934 AM EST SAT FEB 28 2015

.SYNOPSIS...
HIGH PRESSURE WILL BUILD OVER THE REGION TODAY AND WILL SHIFT
OFFSHORE SUNDAY. WEAK LOW PRESSURE CROSSES THE REGION SUNDAY
NIGHT...PRODUCING SOME ACCUMULATING SNOW...BEFORE MOVING INTO THE
CANADIAN MARITIMES ON MONDAY. HIGH PRESSURE CROSSES THE AREA
MONDAY NIGHT AND TUESDAY. LOW PRESSURE WILL MOVE OUT OF THE GREAT
LAKES TUESDAY NIGHT AND WILL TRACK NORTHEAST THROUGH THE ST
LAWRENCE VALLEY ON WEDNESDAY...BRINGING A ROUND OF MIXED
PRECIPITATION TO THE AREA. A COLD FRONT FOLLOWS WEDNESDAY NIGHT.
HIGH PRESSURE BUILDS IN FOR THE END OF THE WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
UPDATE...
HAVE UPDATED THE GRIDS BASED ON CURRENT TRENDS AND CONDITIONS. -7
DEGREES IN PORTLAND LAST NIGHT WAS VERY CLOSE TO THE ALL-TIME
RECORD LOW OF -9. EXPECT TO FORECAST BELOW MODEL GUIDANCE AGAIN
TONIGHT FOR THE MIN TEMPERATURES.

SUNNY FOR THE REST OF TODAY...WITH LIGHT WINDS. FREEZING SPRAY
ADVISORY WILL END SHORTLY.

PREV DISC...
HIGH PRESSURE WILL CONTINUE TO BUILD IN FROM THE WEST
TODAY PROVIDING SUNNY SKIES AND SLIGHTLY WARMER TEMPS. HIGHS WILL
RANGE FROM THE UPPER TEENS TO LOWER 20S NORTH AND MID TO UPPER 20S
SOUTH.

&&

.SHORT TERM /SUNDAY/...
HIGH PRESSURE WILL CREST OVER THE REGION TONIGHT. GOOD RADIATIONAL
COOLING WILL AGAIN SEND TEMPS WELL BELOW NORMAL BUT NOT QUITE AS COLD
AS FRIDAY NIGHT. COLDER MOUNTAIN VALLEYS WILL BOTTOM OUT BETWEEN
5 AND 15 BELOW. TEMPERATURES IN THE SOUTH WILL BE BETWEEN 5 ABOVE
AND 5 BELOW. EXPECT SOME HIGH CLOUDS TO FILTER IN FROM THE WEST
AFTER MIDNIGHT.

CLOUDS WILL BE ON THE INCREASE SUNDAY AS HIGH PRESSURE SHIFTS EAST
AND A COLD FRONT APPROACHES FROM THE WEST. HAVE GONE WITH LOW
CHANCE POPS FOR SOUTHWEST ZONES FOR LATE IN THE DAY BUT EXPECT ANY
SNOW SHOWERS TO BE LIGHT AND SPOTTY. HIGH TEMPS WILL CONTINUE
BELOW NORMAL WITH READINGS RANGING THROUGH THE 20S TO NEAR 30.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
500 MB PATTERN IN THE EXTENDED LOOKS TO REMAIN MOSTLY UNCHANGED
THROUGH THE EXTENDED ALTHOUGH STARTING TO SEE SOME SEASONAL
SHIFTING OF THE JET BACK TOWARD THE POLE. ALSO...SOME WEAKEN IN
BOTH THE UPSTREAM AND DOWNSTREAM BLOCKS WILL ALLOW FOR SOME MORE
COMPACT AND PROGRESSIVE WAVES TO DEVELOP WHICH SHOULD HELP
TRANSPORT SOME WARMER INTO THE NERN CONUS...AT LEAST FOR SHORT
PERIODS.

FIRST ON THE AGENDA IS THE FAST MOVING WAVE THAT SWINGS SE OUT OF
THE CANSDI9AN PRAIRIE AND THEN SHIFTS INTO NEW ENGLAND BEFORE
SHOWING A BIT OF A NEGATIVE TILT. LOOKS LIKE THE ENERGY GET S INTO
THE BASE OF THIS TROUGH TO LATE TO DEEPEN THE SFC LOW UNTIL IT IS
TO OUR EAST...AND SO WE WILL SOME SNOW LATE SUNDAY AND MAINLY
SUNDAY NIGHT. QPF LOOKS TO COME IN THE AROUND 0.20-0.25" FAIRLY
EVENLY ACROSS THE CWA...AND THIS SHOULD GENERALLY TRANSLATE TO
2-4" OF SNOW GIVEN SNOWFALL RATIOS OF ROUGHLY 10-15 TO 1. HIGHEST
AMTS LOOK TO BE IN THE SRN THIRD OF NH...WITH LOWEST AMTS IN
INTERIOR CENTRAL ME.  SNOW SHOULD WIND DOWN IN MOST PLACES BY
12Z...WITH WEST WINDS PICKING UP BY MIDDAY AND TEMPS RISING INTO
THE LOW-MID 30S NEAR THE COAST AND IN SRN NH...AND IN THE MID-
UPPER 30S IN THE NORTH. COLD AIR FILTERS IN MON NIGHT WITH LOWS
DROPPING BACK DOWN BETWEEN -5 AND +10 F. TUE WILL BE A LITTLE
COLDER AS LIGHT FLOW BECOMES MORE ONSHORE AND CLOUDS ROLL IN FROM
THE NEXT APPROACHING FROM THE SW.

THIS NEXT SYSTEM WILL FEATURE A 500MB CLOSED LOW WELL TO OUR NW
AND A FEW WEAK WAVES ROTATING AROUND IT AND GRADUALLY FLATTENING
OUT THE RIDGE UNTIL THE KICKER WAVE COME THRU ON THU. THIS WILL
KEEP THINGS UNSETTLED FROM TUE NIGHT INTO THE THU...ALTHOUGH THE
HIGHEST CONFIDENCE IN PRECIP OCCURRING FOR NOW TUE NIGHT INTO WED
MORNING. IT WILL START OUT AS SNOW...BUT IT WILL BE ACCOMPANIED BY
DECENT SW FLOW ALOFT...AND MAIN CHUNK OF HIGH SHIFTS OFF TO THE
EAST AND DOES NOT ENTRENCH ITSELF TO THE NE. THIS SHOULD ALLOW
THE WARN AIR TO MOVE IN FAIRLY CLOSE TO THE SFC. THE QUESTION IS
HOW LONG DOES THE COLD AIR DAM AT THE SFC HOLD ON...GIVEN THE DEEP
SNOWPACK. MODELS ARE PROBABLY OVERDOING THE WARM TO SOME DEGREE.
HAVE INCLUDED FZRA IN THE MIX ON WED. STILL SYSTEM IS FAIRLY
PROGRESSIVE AND QPFS GENERALLY LOOK TO BE IN THE HALF INCH
BALLPARK...SO NOT A BIG EVENT FOR NOW.

MODELS DO WANT TO STALL THE FRONT JUST TO OR S WED NIGHT INTO
THU...AND THEN DEVELOP A WAVE ALONG THE FRONT. FOR NOW MODELS
GENERALLY AGREE THAT MOST OF ANY PRECIP STAYS TO OUR S...BUT HAVE
KEPT THE CHC POPS IN THE FORECAST TO COVER THIS POSSIBILITY.
COLDER HIGH PRESSURE THEN BUILDS IN FOR FRI.

&&

.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
SHORT TERM...VFR TODAY THROUGH TONIGHT. AREAS OF MVFR CIGS
DEVELOPING LATE SUNDAY.

LONG TERM...WILL LKLY SEE IFR CIGS/VIS IN SN FOR A GOOD CHUNK OF
SUN NIGHT AT ALL TERMINALS...BUT SHOULD SEE RAPID IMPROVEMENT OT
VFR FORM SW TO NE DURING MON MORNING /EXCEPT KHIE WHICH WILL SEE
OCCNL MVFR-IFR IN SHSN THRU MON AFTERNOON. VFR HOLDS MON NIGHT AND
TUE BEFORE ANOTHER SYSTEM MOVES IN TUE AND WILL PRODUCE FLIGHT
RESTRICTIONS LATE TUE NIGHT INTO WED.

&&

.MARINE...
SHORT TERM...FREEZING SPRAY ADVISORY THROUGH LATE MORNING.

LONG TERM...EXPECT TO NEED AN SCA MONDAY AFT INTO MON NIGHT IN W
FLOW. MAY NEED GALES FOR A PERIOD LATE MON AND MON
EVENING...BEFORE WINDS DIMINISH LATE MON NIGHT. SCA MAY BE NEEDED
AGAIN IN SW FLOW LATE TUE NIGH AND WED.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...FREEZING SPRAY ADVISORY UNTIL NOON EST TODAY FOR ANZ150>152.

&&

$$




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