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000
FXUS61 KBOX 221506
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
1006 AM EST MON DEC 22 2014

.SYNOPSIS...
A WAVE OF LOW PRESSURE WILL BRING PERIODS OF WET WEATHER MAINLY LATE
TONIGHT INTO TUESDAY NIGHT...WHICH MAY BEGIN AS A BRIEF PERIOD OF
FROZEN PRECIPITATION ACROSS NORTHWEST AND NORTH CENTRAL
MASSACHUSETTS.  A MUCH STRONGER STORM PASSING WELL TO OUR WEST
WEDNESDAY INTO CHRISTMAS MORNING WILL BRING HEAVY RAIN...GUSTY WINDS
AND PROBABLY MINOR COASTAL FLOODING.  DRY WEATHER WITH ABOVE NORMAL
TEMPERATURES EXPECTED CHRISTMAS AFTERNOON INTO SATURDAY.  LOW
PRESSURE MAY BRING A RETURN TO UNSETTLED WEATHER BY NEXT SUNDAY.

&&

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

EAST TO SOUTHEAST FLOW WAS WEAK LATE MORNING BUT EXPECTED TO
INCREASE DURING THE AFTERNOON AND EVENING. THIS WILL MAINTAIN THE
INFLOW OF MOIST AIR...WHICH WILL MAINTAIN CLOUDS AND MAY LOWER
CLOUD BASES DURING THE AFTERNOON/EVENING. MAIN FOCUS OF SHOWER
POTENTIAL WILL BE OVER THE EASTERN WATERS AND PARTS OF EASTERN
MASSACHUSETTS.

TEMPS ALOFT ARE COLD ENOUGH FOR SNOW ACROSS THE INTERIOR.
SOUTHEAST SECTIONS ARE WARM ENOUGH TO SUPPORT RAIN.

AS FOR HIGH TEMPS...LOW LEVEL NORTHEAST FLOW AND CLOUDY SKIES
PROBABLY KEEP HIGHS IN THE MIDDLE 30S ACROSS THE INTERIOR. ONSHORE
FLOW WILL ALLOW COASTAL LOCATIONS TO SEE HIGHS IN THE UPPER
30S TO THE LOWER 40S...WITH MIDDLE TO UPPER 40S ON CAPE AND
ISLANDS.

&&

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

*LIGHT FREEZING RAIN IS POSSIBLE ACROSS THE INTERIOR NORTHWEST AND
  NORTHERN WORCESTER HILLS*

A WEAK AREA OF LOW PRESSURE DEVELOPS ALONG A WARM FRONT OFF THE MID
ATLANTIC...DRIFTING NORTHWARD TOWARD THE AREA. THIS LOW REMAINS WEAK
AS THE WARM FRONT MOVES SLOWLY NORTHWARD TONIGHT INTO TOMORROW.
DECENT WARM ADVECTION AHEAD OF THIS WAVE WITH SEVERAL HI-RES
GUIDANCE MODELS SHOWS A POTENTIAL FOR COLD AIR DAMMING ACROSS THE
INTERIOR INTO TUESDAY MORNING.  BIGGEST QUESTION WILL BE THE
MOISTURE POTENTIAL...IS THERE ENOUGH TO DEVELOP PRECIP ESP TONIGHT?
GUIDANCE DOES SHOW ENOUGH LIFT AHEAD OF APPROACHING SURFACE LOW PER
THE GFS/EC SO ANTICIPATE PRECIP TO DEVELOP AND OVERSPREAD ACROSS
SOUTHERN NEW ENGLAND. IF THIS PLAYS OUT WITH COLD AIR DAMMING AND
WARM AIR ADVECTION...THEN WE COULD SEE FREEZING RAIN/DRIZZLE ACROSS
THE INTERIOR NORTHWEST AND NORTHERN WORCESTER HILLS VERY LATE
TONIGHT INTO TUESDAY MORNING. A WINTER WEATHER ADVISORY MAY BE
NEEDED.

AS SURFACE LOW CONTINUES TO MOVE NORTHWARD...AND HIGH PRESSURE OVER
EASTERN CANADA...ANTICIPATE AN INCREASING LLJ. THIS SOUTHEASTERLY
JET WILL CONTINUE TO FEED MOISTURE INTO THE REGION AND WITH
SOUNDINGS SHOW A VERY SATURATED PROFILE COULD SEE NUMEROUS SHOWERS
WITH PERHAPS A FEW HEAVY DOWNPOURS. NOTICED GUIDANCE HAS
INCREASED THE QPF OVER THE PAST FEW DAYS. AS THE WEAK SURFACE LOW
MOVES NORTH OF SOUTHERN NEW ENGLAND...WARM FRONT WILL LIFT
NORTHWARD SO ALL PRECIP BY THE LATE MORNING WILL BE IN THE LIQUID
FORM.

WE COULD ALSO SEE SOME MINOR COASTAL FLOODING CONCERNS ON TUESDAY
WITH DUE EASTERLY FLOW INCREASING TO ABOUT 20 TO 25 MPH.  SEE BELOW
FOR MORE DETAILS.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
HIGHLIGHTS...

* PERIODS OF RAIN TUE NIGHT INTO XMAS MORNING WILL BE HEAVY AT TIMES
* DRY BY CHRISTMAS AFTERNOON BUT WINDY
* TEMPS AROUND 60 FOR SOME LATE WED INTO CHRISTMAS MORNING
* DRY BUT ABOVE NORMAL TEMPS CONTINUE FRI AND SAT
* UNSETTLED WEATHER MAY RETURN BY SUN BUT LOW CONFIDENCE

DETAILS...

TUESDAY NIGHT INTO CHRISTMAS...

STRONG SHORTWAVE WILL DIG ACROSS THE CENTRAL U.S. AND ALLOW DEEP
SOUTH TO SOUTHWEST FLOW ALOFT ACROSS SOUTHERN NEW ENGLAND.  THIS
WILL SEND AND ANOMALOUS MILD AIRMASS INTO SOUTHERN NEW ENGLAND FOR
LATE DECEMBER.  GEFS SHOWING PWATS 4 TO 5 STANDARD DEVIATIONS ABOVE
NORMAL BY WED NIGHT ACROSS OUR REGION.  WHILE HEAVY RAIN IS STILL
EXPECTED...THE MODELS HAVE CUT DOWN ON THE QPF IN THE LAST FEW RUNS.
THE MAIN LOW STILL PASSES WELL TO OUR WEST ACROSS GREAT LAKES...BUT
THEIR SLOWER AND WEAKER WITH SECONDARY DEVELOPMENT ACROSS OUR
REGION.  THIS RESULTS IN A WEAKER LOW LEVEL JET...HENCE LESS QPF.
GIVEN ANOMALOUS PWATS IN PLACE...DO NOT WANT TO COMPLETELY LET OUR
GUARD DOWN WITH THE POTENTIAL FOR FLOODING...BUT DOES APPEAR
SOMEWHAT LESS OF A RISK THAN YESTERDAY.  NONETHELESS...STILL EXPECT
TYPICAL NUISANCE POOR DRAINAGE STREET FLOODING.

AS FOR TIMING...SOUTHERLY FLOW ALOFT WILL RESULT IN SCATTERED
SHOWERS TUE NIGHT.  BULK OF THE RAIN WILL OCCUR WED INTO EARLY
CHRISTMAS DAY WHEN STRONGEST FORCING COINCIDES HIGH PWAT AIRMASS.
SOME OF THIS RAIN WILL BE HEAVY AT TIMES MAY RESULT IN NUISANCE POOR
DRAINAGE STREET FLOODING.  STILL A LOW RISK FOR MORE SIGNIFICANT
FLOODING GIVEN EXTREMELY HIGH PWATS...BUT SLOWER DEVELOPMENT OF
SECONDARY LOW PRESSURE MAY BE A LIMITING FACTOR.  REGARDLESS...
EXPECT 1 TO 3 INCHES OF RAIN.  WILL CONTINUE TO MENTION A SLIGHT
CHANCE OF THUNDER WITH SHOWALTER INDICES NEAR ZERO.

THE BULK OF THE RAIN SHOULD COME TO AN END CHRISTMAS MORNING WITH
TEMPS PROBABLY AROUND 60 FOR MUCH OF THE REGION.  WHILE GUSTY
SOUTHERLY WINDS ARE EXPECTED WED NIGHT...INVERSION AND WEAKER LOW
LEVEL JET WILL PROBABLY KEEP MOST AREAS BELOW ADVISORY CRITERIA.
STILL HAVE TO WATCH FOR A SMALL WINDOW ON THE COASTAL PLAIN ESP IF
TEMPS CAN EXCEED 60...BUT HIGHER CONFIDENCE IN WIND ON CHRISTMAS
AFTERNOON AND EVENING BEHIND THE SYSTEM.  INCREASING WESTERLY WIND
ALOFT AND STEEPENING LAPSE RATES WILL BRING THE POTENTIAL FOR THESE
WINDS.  DECENT SHOT AT A PERIOD OF 35 TO 50 MPH GUSTS BEHIND THIS
SYSTEM CHRISTMAS AFTERNOON AND EVENING.  WHILE THE GFS IS AN
OUTLIER...IT WOULD EVEN SUGGEST THE POTENTIAL FOR HIGH WIND CRITERIA
TO BE MET WITH 70 KNOTS AT 850 MB.  THAT MAY BE OVERDONE...BUT
SOMETHING WILL HAVE TO KEEP AN EYE ON THE NEXT FEW DAYS.

FRIDAY AND SATURDAY...

UPPER LEVEL RIDGE OFF THE SOUTHEAST COAST WILL KEEP KEEP US IN MILD
SOUTHWEST FLOW ALOFT.  DRY WEATHER EXPECTED WITH FORCING FOR ANY
PRECIPITATION WILL TO OUR NORTHWEST.  HIGHS MAINLY IN THE 40S TO
LOWER 50S.

SUNDAY...

CONFIDENCE IN THE FORECAST GOES DOWN CONSIDERABLY OVER THIS TIME.
DEVELOPING UPPER LEVEL RIDGING INTO ALASKA WILL SEND THE POLAR JET
SOUTHWARD INTO THE CENTRAL U.S.  AT THE SAME TIME...UPPER LEVEL
RIDGE OFF THE SOUTHEAST COAST WILL TRY TO HANG TOUGH.  THE GFS
INSISTS ON DRY AND COLDER WEATHER ARRIVING...BUT WERE NOT CONVINCED.
GIVEN THE SOUTHEAST RIDGE...IT MAY HOLD THE COLD AIR UP AND ALLOW
DEVELOPING LOW PRESSURE TO TRACK NEAR NEW ENGLAND SUN AND SUN NIGHT.
THIS COULD BRING RAIN OR SNOW DEPENDING ON ITS TRACK...OBVIOUSLY A
WEEK OUT SO PLENTY OF UNCERTAINTY BUT WOULD LEAN TOWARDS ANOTHER
SYSTEM AND AWAY FROM THE DRY GFS.

&&

.AVIATION /15Z MONDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /THROUGH TUESDAY/...

THIS AFTERNOON...HIGH CONFIDENCE. MAINLY MVFR CONDITIONS BUT SOME
LOCALIZED IFR CONDITIONS POSSIBLE ALONG THE COAST AND IN THE
WORCESTER HILLS. A FEW SHOWERS EXPECTED ALONG EASTERN MA COAST
WITH PERHAPS A PASSING FLURRY/SNOW SHOWER OR TWO ACROSS THE
INTERIOR.

TONIGHT...MODERATE CONFIDENCE. MAINLY MVFR CONDITIONS CONTINUE IN
SCATTERED LIGHT SNOW SHOWERS. LIGHT FZRA POSSIBLE LATE MONDAY NIGHT
ACROSS NW MASSACHUSETTS.

TUESDAY...MODERATE CONFIDENCE. MVFR CONDITIONS MAY DROP TO IFR
WITHIN AND HEAVY RAIN FALL. VSBYS WILL BE REDUCED TO 5SM OR LESS
AS WELL.

KBOS TERMINAL...MODERATE CONFIDENCE.

KBDL TERMINAL...MODERATE CONFIDENCE.

OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY...

TUESDAY NIGHT INTO THURSDAY MORNING...MODERATE CONFIDENCE.
WIDESPREAD LOW END MVFR TO IFR CONDITIONS EXPECTED IN PERIODS OF
HEAVY SHOWERS/LOW CLOUDS AND FOG PATCHES.  A PERIOD OF SOUTHERLY
WIND GUSTS OF 30 TO 40 KNOTS EXPECTED ON THE COASTAL PLAIN WED
NIGHT.  LLWS ALSO A CONCERN FOR THE ENTIRE REGION WED INTO EARLY THU.

THURSDAY AFTERNOON INTO FRIDAY...MODERATE TO HIGH CONFIDENCE IN
MAINLY VFR.  HOWEVER...A PERIOD OF WESTERLY 30 TO 45 KNOT WIND GUSTS
POSSIBLE THU AFTERNOON AND EVENING.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /THROUGH TUESDAY/...MODERATE TO HIGH CONFIDENCE.

HIGH PRESSURE ACROSS QUEBEC AND THE MARITIMES WILL RESULT IN
PERSISTENT NORTHEASTERLY TO EASTERLY WINDS ACROSS THE WATERS THIS
AFTERNOON. LOW PRESSURE MOVING UP THE COAST WILL TIGHTEN THE
PRESSURE GRADIENT A LITTLE THIS AFTERNOON...AND MAY ALLOW WINDS TO
GUST AROUND 20 KNOTS OR IN THE LOW 20S. THE PERSISTANT ESE FLOW
WILL ALLOW SEAS TO BUILD TO 5 FEET ON THE EASTERN OUTER
WATERS...WITH 2-4 FEET MOST OTHER WATERS. SMALL CRAFT ADVISORY
CONTINUES.

APPROACHING SURFACE LOW PRESSURE FROM THE MID-ATLANTIC TONIGHT WILL
HELP INCREASE AN EASTERLY LLJ OVER THE WATER TOMORROW. THIS WILL
BUILD THE SEAS BETWEEN 5-8 FT. COULD SEE WIND GUSTS BETWEEN 20-30
KTS AS THE FRONT PASSES. SCA HAS BEEN EXPANDED ACCORDINGLY.

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

TUESDAY NIGHT...LONG FETCH EASTERLY FLOW WILL CONTINUE TO RESULT IN
SCA SEAS ACROSS THE OUTER-WATERS WITH HIGH PRESSURE MOVING EAST OF
THE CANADIAN MARITIMES.  WINDS SHOULD GENERALLY BE BELOW SMALL CRAFT
THRESHOLDS.

WEDNESDAY INTO EARLY THURSDAY...INTENSIFYING LOW PRESSURE PASSING
WELL TO OUR WEST WILL CAUSE WINDS TO TURN SOUTHERLY AND BECOME
GUSTY. SMALL CRAFT WIND GUSTS ARE A LOCK.  THE MAIN UNCERTAINTY IS
DO WE SEE SOUTHERLY GALES DEVELOP WED NIGHT.  STRONG LOW LEVEL JET
PRESENT...BUT WE WILL BE DEALING WITH AN INVERSION OVER THE
RELATIVELY COOL OCEAN.  REGARDLESS...STILL SHOULD SEE AT LEAST A
PERIOD OF NEAR GALE FORCE SOUTHERLY WIND GUSTS.

LATER THURSDAY INTO FRIDAY...A PERIOD OF WESTERLY GALE FORCE WIND
GUSTS APPEARS LIKELY IN THE COLD ADVECTION PATTERN BEHIND THE STORM
THU AFTERNOON AND NIGHT.  WINDS SHOULD DIMINISH SOME ON FRIDAY.

&&

.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES OCCUR TUE AND WED.

EAST MASSACHUSETTS COAST:

TUESDAY...HIGH TIDE AT BOSTON WILL BE 11.6 FT AT MIDDAY. WINDS WILL
BE FROM THE EAST AT 10 TO 15 KNOTS...SO THERE WILL BE ONSHORE FLOW
DURING THIS HIGH TIDE.  WHILE THIS IS NOTHING TOO STRONG...GIVEN THE
HIGH ASTRO TIDE EXPECT SOME SPLASH OVER/MINOR COASTAL FLOODING.
CERTAINLY DO NOT EXPECT TO SEE ANY SIGNIFICANT ISSUES.

WEDNESDAY...HIGH TIDE AT BOSTON WILL BE 11.7 FT AT MIDDAY.  WINDS
WILL BE FROM THE SOUTHEAST NEAR 10 KNOTS BUT THERE WILL BE SOME
PRESSURE FALLS WITH INTENSIFYING LOW PRESSURE TO OUR WEST.  THIS
SHOULD BE ENOUGH FOR MORE SPLASH OVER/MINOR COASTAL FLOODING WITH
THE HIGH ASTRO TIDES.  HOWEVER...DO NOT EXPECT ANY SIGNIFICANT
PROBLEMS GIVEN WINDS/SEAS SHOULD BE HELD IN CHECK DURING THE TIME OF
HIGH TIDE.

SOUTH COAST:

WEDNESDAY EVENING...SOUTHERLY WINDS ARE EXPECTED AND ASTRONOMICAL
TIDES INCREASE ALONG THE SOUTH COAST. HIGH TIDE IN PROVIDENCE WILL
BE 5.2 FT THAT EVENING. 925 MB LLJ STRENGTHENS TO 55-65 KTS WHICH
COULD PUSH A 1 TO 2 FOOT SURGE UP ALONG THE SOUTH COAST DURING THE
TIME OF HIGH TIDE.  THE LOW LEVEL INVERSION WILL PROBABLY HOLD THE
STRONGEST WINDS JUST ABOVE THE GROUND...SO THINKING THE RISK IS FOR
SPLASH OVER AND MINOR COASTAL FLOODING.  THERE STILL IS A LOW RISK
FOR MODERATE COASTAL FLOODING...BUT THAT IS OFTEN HARD TO GET IN A
NON-TROPICAL SYSTEM ALONG THE SOUTH COAST.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 1 AM TO 7 PM EST TUESDAY FOR ANZ231-
     232-251-256.
     SMALL CRAFT ADVISORY FROM 1 PM THIS AFTERNOON TO 7 PM EST
     TUESDAY FOR ANZ250-254.
     SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 7 PM EST
     TUESDAY FOR ANZ255.

&&

$$
SYNOPSIS...FRANK/DUNTEN
NEAR TERM...WTB/FRANK
SHORT TERM...DUNTEN
LONG TERM...FRANK
AVIATION...FRANK/DUNTEN
MARINE...WTB/FRANK/DUNTEN
TIDES/COASTAL FLOODING...




000
FXUS61 KBOX 221506
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
1006 AM EST MON DEC 22 2014

.SYNOPSIS...
A WAVE OF LOW PRESSURE WILL BRING PERIODS OF WET WEATHER MAINLY LATE
TONIGHT INTO TUESDAY NIGHT...WHICH MAY BEGIN AS A BRIEF PERIOD OF
FROZEN PRECIPITATION ACROSS NORTHWEST AND NORTH CENTRAL
MASSACHUSETTS.  A MUCH STRONGER STORM PASSING WELL TO OUR WEST
WEDNESDAY INTO CHRISTMAS MORNING WILL BRING HEAVY RAIN...GUSTY WINDS
AND PROBABLY MINOR COASTAL FLOODING.  DRY WEATHER WITH ABOVE NORMAL
TEMPERATURES EXPECTED CHRISTMAS AFTERNOON INTO SATURDAY.  LOW
PRESSURE MAY BRING A RETURN TO UNSETTLED WEATHER BY NEXT SUNDAY.

&&

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

EAST TO SOUTHEAST FLOW WAS WEAK LATE MORNING BUT EXPECTED TO
INCREASE DURING THE AFTERNOON AND EVENING. THIS WILL MAINTAIN THE
INFLOW OF MOIST AIR...WHICH WILL MAINTAIN CLOUDS AND MAY LOWER
CLOUD BASES DURING THE AFTERNOON/EVENING. MAIN FOCUS OF SHOWER
POTENTIAL WILL BE OVER THE EASTERN WATERS AND PARTS OF EASTERN
MASSACHUSETTS.

TEMPS ALOFT ARE COLD ENOUGH FOR SNOW ACROSS THE INTERIOR.
SOUTHEAST SECTIONS ARE WARM ENOUGH TO SUPPORT RAIN.

AS FOR HIGH TEMPS...LOW LEVEL NORTHEAST FLOW AND CLOUDY SKIES
PROBABLY KEEP HIGHS IN THE MIDDLE 30S ACROSS THE INTERIOR. ONSHORE
FLOW WILL ALLOW COASTAL LOCATIONS TO SEE HIGHS IN THE UPPER
30S TO THE LOWER 40S...WITH MIDDLE TO UPPER 40S ON CAPE AND
ISLANDS.

&&

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

*LIGHT FREEZING RAIN IS POSSIBLE ACROSS THE INTERIOR NORTHWEST AND
  NORTHERN WORCESTER HILLS*

A WEAK AREA OF LOW PRESSURE DEVELOPS ALONG A WARM FRONT OFF THE MID
ATLANTIC...DRIFTING NORTHWARD TOWARD THE AREA. THIS LOW REMAINS WEAK
AS THE WARM FRONT MOVES SLOWLY NORTHWARD TONIGHT INTO TOMORROW.
DECENT WARM ADVECTION AHEAD OF THIS WAVE WITH SEVERAL HI-RES
GUIDANCE MODELS SHOWS A POTENTIAL FOR COLD AIR DAMMING ACROSS THE
INTERIOR INTO TUESDAY MORNING.  BIGGEST QUESTION WILL BE THE
MOISTURE POTENTIAL...IS THERE ENOUGH TO DEVELOP PRECIP ESP TONIGHT?
GUIDANCE DOES SHOW ENOUGH LIFT AHEAD OF APPROACHING SURFACE LOW PER
THE GFS/EC SO ANTICIPATE PRECIP TO DEVELOP AND OVERSPREAD ACROSS
SOUTHERN NEW ENGLAND. IF THIS PLAYS OUT WITH COLD AIR DAMMING AND
WARM AIR ADVECTION...THEN WE COULD SEE FREEZING RAIN/DRIZZLE ACROSS
THE INTERIOR NORTHWEST AND NORTHERN WORCESTER HILLS VERY LATE
TONIGHT INTO TUESDAY MORNING. A WINTER WEATHER ADVISORY MAY BE
NEEDED.

AS SURFACE LOW CONTINUES TO MOVE NORTHWARD...AND HIGH PRESSURE OVER
EASTERN CANADA...ANTICIPATE AN INCREASING LLJ. THIS SOUTHEASTERLY
JET WILL CONTINUE TO FEED MOISTURE INTO THE REGION AND WITH
SOUNDINGS SHOW A VERY SATURATED PROFILE COULD SEE NUMEROUS SHOWERS
WITH PERHAPS A FEW HEAVY DOWNPOURS. NOTICED GUIDANCE HAS
INCREASED THE QPF OVER THE PAST FEW DAYS. AS THE WEAK SURFACE LOW
MOVES NORTH OF SOUTHERN NEW ENGLAND...WARM FRONT WILL LIFT
NORTHWARD SO ALL PRECIP BY THE LATE MORNING WILL BE IN THE LIQUID
FORM.

WE COULD ALSO SEE SOME MINOR COASTAL FLOODING CONCERNS ON TUESDAY
WITH DUE EASTERLY FLOW INCREASING TO ABOUT 20 TO 25 MPH.  SEE BELOW
FOR MORE DETAILS.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
HIGHLIGHTS...

* PERIODS OF RAIN TUE NIGHT INTO XMAS MORNING WILL BE HEAVY AT TIMES
* DRY BY CHRISTMAS AFTERNOON BUT WINDY
* TEMPS AROUND 60 FOR SOME LATE WED INTO CHRISTMAS MORNING
* DRY BUT ABOVE NORMAL TEMPS CONTINUE FRI AND SAT
* UNSETTLED WEATHER MAY RETURN BY SUN BUT LOW CONFIDENCE

DETAILS...

TUESDAY NIGHT INTO CHRISTMAS...

STRONG SHORTWAVE WILL DIG ACROSS THE CENTRAL U.S. AND ALLOW DEEP
SOUTH TO SOUTHWEST FLOW ALOFT ACROSS SOUTHERN NEW ENGLAND.  THIS
WILL SEND AND ANOMALOUS MILD AIRMASS INTO SOUTHERN NEW ENGLAND FOR
LATE DECEMBER.  GEFS SHOWING PWATS 4 TO 5 STANDARD DEVIATIONS ABOVE
NORMAL BY WED NIGHT ACROSS OUR REGION.  WHILE HEAVY RAIN IS STILL
EXPECTED...THE MODELS HAVE CUT DOWN ON THE QPF IN THE LAST FEW RUNS.
THE MAIN LOW STILL PASSES WELL TO OUR WEST ACROSS GREAT LAKES...BUT
THEIR SLOWER AND WEAKER WITH SECONDARY DEVELOPMENT ACROSS OUR
REGION.  THIS RESULTS IN A WEAKER LOW LEVEL JET...HENCE LESS QPF.
GIVEN ANOMALOUS PWATS IN PLACE...DO NOT WANT TO COMPLETELY LET OUR
GUARD DOWN WITH THE POTENTIAL FOR FLOODING...BUT DOES APPEAR
SOMEWHAT LESS OF A RISK THAN YESTERDAY.  NONETHELESS...STILL EXPECT
TYPICAL NUISANCE POOR DRAINAGE STREET FLOODING.

AS FOR TIMING...SOUTHERLY FLOW ALOFT WILL RESULT IN SCATTERED
SHOWERS TUE NIGHT.  BULK OF THE RAIN WILL OCCUR WED INTO EARLY
CHRISTMAS DAY WHEN STRONGEST FORCING COINCIDES HIGH PWAT AIRMASS.
SOME OF THIS RAIN WILL BE HEAVY AT TIMES MAY RESULT IN NUISANCE POOR
DRAINAGE STREET FLOODING.  STILL A LOW RISK FOR MORE SIGNIFICANT
FLOODING GIVEN EXTREMELY HIGH PWATS...BUT SLOWER DEVELOPMENT OF
SECONDARY LOW PRESSURE MAY BE A LIMITING FACTOR.  REGARDLESS...
EXPECT 1 TO 3 INCHES OF RAIN.  WILL CONTINUE TO MENTION A SLIGHT
CHANCE OF THUNDER WITH SHOWALTER INDICES NEAR ZERO.

THE BULK OF THE RAIN SHOULD COME TO AN END CHRISTMAS MORNING WITH
TEMPS PROBABLY AROUND 60 FOR MUCH OF THE REGION.  WHILE GUSTY
SOUTHERLY WINDS ARE EXPECTED WED NIGHT...INVERSION AND WEAKER LOW
LEVEL JET WILL PROBABLY KEEP MOST AREAS BELOW ADVISORY CRITERIA.
STILL HAVE TO WATCH FOR A SMALL WINDOW ON THE COASTAL PLAIN ESP IF
TEMPS CAN EXCEED 60...BUT HIGHER CONFIDENCE IN WIND ON CHRISTMAS
AFTERNOON AND EVENING BEHIND THE SYSTEM.  INCREASING WESTERLY WIND
ALOFT AND STEEPENING LAPSE RATES WILL BRING THE POTENTIAL FOR THESE
WINDS.  DECENT SHOT AT A PERIOD OF 35 TO 50 MPH GUSTS BEHIND THIS
SYSTEM CHRISTMAS AFTERNOON AND EVENING.  WHILE THE GFS IS AN
OUTLIER...IT WOULD EVEN SUGGEST THE POTENTIAL FOR HIGH WIND CRITERIA
TO BE MET WITH 70 KNOTS AT 850 MB.  THAT MAY BE OVERDONE...BUT
SOMETHING WILL HAVE TO KEEP AN EYE ON THE NEXT FEW DAYS.

FRIDAY AND SATURDAY...

UPPER LEVEL RIDGE OFF THE SOUTHEAST COAST WILL KEEP KEEP US IN MILD
SOUTHWEST FLOW ALOFT.  DRY WEATHER EXPECTED WITH FORCING FOR ANY
PRECIPITATION WILL TO OUR NORTHWEST.  HIGHS MAINLY IN THE 40S TO
LOWER 50S.

SUNDAY...

CONFIDENCE IN THE FORECAST GOES DOWN CONSIDERABLY OVER THIS TIME.
DEVELOPING UPPER LEVEL RIDGING INTO ALASKA WILL SEND THE POLAR JET
SOUTHWARD INTO THE CENTRAL U.S.  AT THE SAME TIME...UPPER LEVEL
RIDGE OFF THE SOUTHEAST COAST WILL TRY TO HANG TOUGH.  THE GFS
INSISTS ON DRY AND COLDER WEATHER ARRIVING...BUT WERE NOT CONVINCED.
GIVEN THE SOUTHEAST RIDGE...IT MAY HOLD THE COLD AIR UP AND ALLOW
DEVELOPING LOW PRESSURE TO TRACK NEAR NEW ENGLAND SUN AND SUN NIGHT.
THIS COULD BRING RAIN OR SNOW DEPENDING ON ITS TRACK...OBVIOUSLY A
WEEK OUT SO PLENTY OF UNCERTAINTY BUT WOULD LEAN TOWARDS ANOTHER
SYSTEM AND AWAY FROM THE DRY GFS.

&&

.AVIATION /15Z MONDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /THROUGH TUESDAY/...

THIS AFTERNOON...HIGH CONFIDENCE. MAINLY MVFR CONDITIONS BUT SOME
LOCALIZED IFR CONDITIONS POSSIBLE ALONG THE COAST AND IN THE
WORCESTER HILLS. A FEW SHOWERS EXPECTED ALONG EASTERN MA COAST
WITH PERHAPS A PASSING FLURRY/SNOW SHOWER OR TWO ACROSS THE
INTERIOR.

TONIGHT...MODERATE CONFIDENCE. MAINLY MVFR CONDITIONS CONTINUE IN
SCATTERED LIGHT SNOW SHOWERS. LIGHT FZRA POSSIBLE LATE MONDAY NIGHT
ACROSS NW MASSACHUSETTS.

TUESDAY...MODERATE CONFIDENCE. MVFR CONDITIONS MAY DROP TO IFR
WITHIN AND HEAVY RAIN FALL. VSBYS WILL BE REDUCED TO 5SM OR LESS
AS WELL.

KBOS TERMINAL...MODERATE CONFIDENCE.

KBDL TERMINAL...MODERATE CONFIDENCE.

OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY...

TUESDAY NIGHT INTO THURSDAY MORNING...MODERATE CONFIDENCE.
WIDESPREAD LOW END MVFR TO IFR CONDITIONS EXPECTED IN PERIODS OF
HEAVY SHOWERS/LOW CLOUDS AND FOG PATCHES.  A PERIOD OF SOUTHERLY
WIND GUSTS OF 30 TO 40 KNOTS EXPECTED ON THE COASTAL PLAIN WED
NIGHT.  LLWS ALSO A CONCERN FOR THE ENTIRE REGION WED INTO EARLY THU.

THURSDAY AFTERNOON INTO FRIDAY...MODERATE TO HIGH CONFIDENCE IN
MAINLY VFR.  HOWEVER...A PERIOD OF WESTERLY 30 TO 45 KNOT WIND GUSTS
POSSIBLE THU AFTERNOON AND EVENING.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /THROUGH TUESDAY/...MODERATE TO HIGH CONFIDENCE.

HIGH PRESSURE ACROSS QUEBEC AND THE MARITIMES WILL RESULT IN
PERSISTENT NORTHEASTERLY TO EASTERLY WINDS ACROSS THE WATERS THIS
AFTERNOON. LOW PRESSURE MOVING UP THE COAST WILL TIGHTEN THE
PRESSURE GRADIENT A LITTLE THIS AFTERNOON...AND MAY ALLOW WINDS TO
GUST AROUND 20 KNOTS OR IN THE LOW 20S. THE PERSISTANT ESE FLOW
WILL ALLOW SEAS TO BUILD TO 5 FEET ON THE EASTERN OUTER
WATERS...WITH 2-4 FEET MOST OTHER WATERS. SMALL CRAFT ADVISORY
CONTINUES.

APPROACHING SURFACE LOW PRESSURE FROM THE MID-ATLANTIC TONIGHT WILL
HELP INCREASE AN EASTERLY LLJ OVER THE WATER TOMORROW. THIS WILL
BUILD THE SEAS BETWEEN 5-8 FT. COULD SEE WIND GUSTS BETWEEN 20-30
KTS AS THE FRONT PASSES. SCA HAS BEEN EXPANDED ACCORDINGLY.

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

TUESDAY NIGHT...LONG FETCH EASTERLY FLOW WILL CONTINUE TO RESULT IN
SCA SEAS ACROSS THE OUTER-WATERS WITH HIGH PRESSURE MOVING EAST OF
THE CANADIAN MARITIMES.  WINDS SHOULD GENERALLY BE BELOW SMALL CRAFT
THRESHOLDS.

WEDNESDAY INTO EARLY THURSDAY...INTENSIFYING LOW PRESSURE PASSING
WELL TO OUR WEST WILL CAUSE WINDS TO TURN SOUTHERLY AND BECOME
GUSTY. SMALL CRAFT WIND GUSTS ARE A LOCK.  THE MAIN UNCERTAINTY IS
DO WE SEE SOUTHERLY GALES DEVELOP WED NIGHT.  STRONG LOW LEVEL JET
PRESENT...BUT WE WILL BE DEALING WITH AN INVERSION OVER THE
RELATIVELY COOL OCEAN.  REGARDLESS...STILL SHOULD SEE AT LEAST A
PERIOD OF NEAR GALE FORCE SOUTHERLY WIND GUSTS.

LATER THURSDAY INTO FRIDAY...A PERIOD OF WESTERLY GALE FORCE WIND
GUSTS APPEARS LIKELY IN THE COLD ADVECTION PATTERN BEHIND THE STORM
THU AFTERNOON AND NIGHT.  WINDS SHOULD DIMINISH SOME ON FRIDAY.

&&

.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES OCCUR TUE AND WED.

EAST MASSACHUSETTS COAST:

TUESDAY...HIGH TIDE AT BOSTON WILL BE 11.6 FT AT MIDDAY. WINDS WILL
BE FROM THE EAST AT 10 TO 15 KNOTS...SO THERE WILL BE ONSHORE FLOW
DURING THIS HIGH TIDE.  WHILE THIS IS NOTHING TOO STRONG...GIVEN THE
HIGH ASTRO TIDE EXPECT SOME SPLASH OVER/MINOR COASTAL FLOODING.
CERTAINLY DO NOT EXPECT TO SEE ANY SIGNIFICANT ISSUES.

WEDNESDAY...HIGH TIDE AT BOSTON WILL BE 11.7 FT AT MIDDAY.  WINDS
WILL BE FROM THE SOUTHEAST NEAR 10 KNOTS BUT THERE WILL BE SOME
PRESSURE FALLS WITH INTENSIFYING LOW PRESSURE TO OUR WEST.  THIS
SHOULD BE ENOUGH FOR MORE SPLASH OVER/MINOR COASTAL FLOODING WITH
THE HIGH ASTRO TIDES.  HOWEVER...DO NOT EXPECT ANY SIGNIFICANT
PROBLEMS GIVEN WINDS/SEAS SHOULD BE HELD IN CHECK DURING THE TIME OF
HIGH TIDE.

SOUTH COAST:

WEDNESDAY EVENING...SOUTHERLY WINDS ARE EXPECTED AND ASTRONOMICAL
TIDES INCREASE ALONG THE SOUTH COAST. HIGH TIDE IN PROVIDENCE WILL
BE 5.2 FT THAT EVENING. 925 MB LLJ STRENGTHENS TO 55-65 KTS WHICH
COULD PUSH A 1 TO 2 FOOT SURGE UP ALONG THE SOUTH COAST DURING THE
TIME OF HIGH TIDE.  THE LOW LEVEL INVERSION WILL PROBABLY HOLD THE
STRONGEST WINDS JUST ABOVE THE GROUND...SO THINKING THE RISK IS FOR
SPLASH OVER AND MINOR COASTAL FLOODING.  THERE STILL IS A LOW RISK
FOR MODERATE COASTAL FLOODING...BUT THAT IS OFTEN HARD TO GET IN A
NON-TROPICAL SYSTEM ALONG THE SOUTH COAST.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 1 AM TO 7 PM EST TUESDAY FOR ANZ231-
     232-251-256.
     SMALL CRAFT ADVISORY FROM 1 PM THIS AFTERNOON TO 7 PM EST
     TUESDAY FOR ANZ250-254.
     SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 7 PM EST
     TUESDAY FOR ANZ255.

&&

$$
SYNOPSIS...FRANK/DUNTEN
NEAR TERM...WTB/FRANK
SHORT TERM...DUNTEN
LONG TERM...FRANK
AVIATION...FRANK/DUNTEN
MARINE...WTB/FRANK/DUNTEN
TIDES/COASTAL FLOODING...





000
FXUS61 KBOX 221201
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
700 AM EST MON DEC 22 2014

.SYNOPSIS...

A WAVE OF LOW PRESSURE WILL BRING PERIODS OF WET WEATHER MAINLY LATE
TONIGHT INTO TUESDAY NIGHT...WHICH MAY BEGIN AS A BRIEF PERIOD OF
FROZEN PRECIPITATION ACROSS NORTHWEST AND NORTH CENTRAL
MASSACHUSETTS.  A MUCH STRONGER STORM PASSING WELL TO OUR WEST
WEDNESDAY INTO CHRISTMAS MORNING WILL BRING HEAVY RAIN...GUSTY WINDS
AND PROBABLY MINOR COASTAL FLOODING.  DRY WEATHER WITH ABOVE NORMAL
TEMPERATURES EXPECTED CHRISTMAS AFTERNOON INTO SATURDAY.  LOW
PRESSURE MAY BRING A RETURN TO UNSETTLED WEATHER BY NEXT SUNDAY.

&&

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

7 AM UPDATE...

DESPITE UPPER LEVEL RIDGING ALOFT...EAST TO SOUTHEAST FLOW JUST OFF
THE DECK WAS ENOUGH TO RESULT IN LOW LEVEL LIFT FOR SCATTERED RAIN
SHOWERS JUST EAST OF THE MA COAST.  BASED ON RADAR IMAGERY AND
LATEST MESOSCALE MODELS...OPTED TO INCREASE POPS TODAY
ACROSS EASTERN NEW ENGLAND FOR SCATTERED SHOWERS.  PTYPE...ON
EASTERN MA COAST MAINLY RAIN SHOWERS BUT A FEW FLAKES COULD MIX IN
ACROSS NORTHEAST MA THIS MORNING. FURTHER INLAND...ACROSS THE
INTERIOR IT WILL BE COLD ENOUGH FOR A FEW SNOW SHOWERS/FLURRIES BUT
MAIN FOCUS WILL BE ON THE EASTERN MA COAST. THEREFORE...JUST
EXPECT A FEW SNOW SHOWERS/FLURRIES AND MUCH OF THE DAY WILL BE DRY
ACROSS THE INTERIOR.

AS FOR HIGH TEMPS...LOW LEVEL NORTHEAST FLOW AND CLOUDY SKIES
PROBABLY KEEP HIGHS IN THE MIDDLE 30S ACROSS THE INTERIOR. ONSHORE
FLOW WILL ALLOW COASTAL LOCATIONS TO SEE HIGHS IN THE UPPER
30S TO THE LOWER 40S...WITH EVEN MIDDLE 40S ON CAPE AND ISLANDS.

&&

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

*LIGHT FREEZING RAIN IS POSSIBLE ACROSS THE INTERIOR NORTHWEST AND
  NORTHERN WORCESTER HILLS*

A WEAK AREA OF LOW PRESSURE DEVELOPS ALONG A WARM FRONT OFF THE MID
ATLANTIC...DRIFTING NORTHWARD TOWARD THE AREA. THIS LOW REMAINS WEAK
AS THE WARM FRONT MOVES SLOWLY NORTHWARD TONIGHT INTO TOMORROW.
DECENT WARM ADVECTION AHEAD OF THIS WAVE WITH SEVERAL HI-RES
GUIDANCE MODELS SHOWS A POTENTIAL FOR COLD AIR DAMMING ACROSS THE
INTERIOR INTO TUESDAY MORNING.  BIGGEST QUESTION WILL BE THE
MOISTURE POTENTIAL...IS THERE ENOUGH TO DEVELOP PRECIP ESP TONIGHT?
GUIDANCE DOES SHOW ENOUGH LIFT AHEAD OF APPROACHING SURFACE LOW PER
THE GFS/EC SO ANTICIPATE PRECIP TO DEVELOP AND OVERSPREAD ACROSS
SOUTHERN NEW ENGLAND. IF THIS PLAYS OUT WITH COLD AIR DAMMING AND
WARM AIR ADVECTION...THEN WE COULD SEE FREEZING RAIN/DRIZZLE ACROSS
THE INTERIOR NORTHWEST AND NORTHERN WORCESTER HILLS VERY LATE
TONIGHT INTO TUESDAY MORNING. A WINTER WEATHER ADVISORY MAY BE
NEEDED.

AS SURFACE LOW CONTINUES TO MOVE NORTHWARD...AND HIGH PRESSURE OVER
EASTERN CANADA...ANTICIPATE AN INCREASING LLJ. THIS SOUTHEASTERLY
JET WILL CONTINUE TO FEED MOISTURE INTO THE REGION AND WITH
SOUNDINGS SHOW A VERY SATURATED PROFILE COULD SEE NUMEROUS SHOWERS
WITH PERHAPS A FEW HEAVY DOWNPOURS. NOTICED GUIDANCE HAS
INCREASED THE QPF OVER THE PAST FEW DAYS. AS THE WEAK SURFACE LOW
MOVES NORTH OF SOUTHERN NEW ENGLAND...WARM FRONT WILL LIFT
NORTHWARD SO ALL PRECIP BY THE LATE MORNING WILL BE IN THE LIQUID
FORM.

WE COULD ALSO SEE SOME MINOR COASTAL FLOODING CONCERNS ON TUESDAY
WITH DUE EASTERLY FLOW INCREASING TO ABOUT 20 TO 25 MPH.  SEE BELOW
FOR MORE DETAILS.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
HIGHLIGHTS...

* PERIODS OF RAIN TUE NIGHT INTO XMAS MORNING WILL BE HEAVY AT TIMES
* DRY BY CHRISTMAS AFTERNOON BUT WINDY
* TEMPS AROUND 60 FOR SOME LATE WED INTO CHRISTMAS MORNING
* DRY BUT ABOVE NORMAL TEMPS CONTINUE FRI AND SAT
* UNSETTLED WEATHER MAY RETURN BY SUN BUT LOW CONFIDENCE

DETAILS...

TUESDAY NIGHT INTO CHRISTMAS...

STRONG SHORTWAVE WILL DIG ACROSS THE CENTRAL U.S. AND ALLOW DEEP
SOUTH TO SOUTHWEST FLOW ALOFT ACROSS SOUTHERN NEW ENGLAND.  THIS
WILL SEND AND ANOMALOUS MILD AIRMASS INTO SOUTHERN NEW ENGLAND FOR
LATE DECEMBER.  GEFS SHOWING PWATS 4 TO 5 STANDARD DEVIATIONS ABOVE
NORMAL BY WED NIGHT ACROSS OUR REGION.  WHILE HEAVY RAIN IS STILL
EXPECTED...THE MODELS HAVE CUT DOWN ON THE QPF IN THE LAST FEW RUNS.
THE MAIN LOW STILL PASSES WELL TO OUR WEST ACROSS GREAT LAKES...BUT
THEIR SLOWER AND WEAKER WITH SECONDARY DEVELOPMENT ACROSS OUR
REGION.  THIS RESULTS IN A WEAKER LOW LEVEL JET...HENCE LESS QPF.
GIVEN ANOMALOUS PWATS IN PLACE...DO NOT WANT TO COMPLETELY LET OUR
GUARD DOWN WITH THE POTENTIAL FOR FLOODING...BUT DOES APPEAR
SOMEWHAT LESS OF A RISK THAN YESTERDAY.  NONETHELESS...STILL EXPECT
TYPICAL NUISANCE POOR DRAINAGE STREET FLOODING.

AS FOR TIMING...SOUTHERLY FLOW ALOFT WILL RESULT IN SCATTERED
SHOWERS TUE NIGHT.  BULK OF THE RAIN WILL OCCUR WED INTO EARLY
CHRISTMAS DAY WHEN STRONGEST FORCING COINCIDES HIGH PWAT AIRMASS.
SOME OF THIS RAIN WILL BE HEAVY AT TIMES MAY RESULT IN NUISANCE POOR
DRAINAGE STREET FLOODING.  STILL A LOW RISK FOR MORE SIGNIFICANT
FLOODING GIVEN EXTREMELY HIGH PWATS...BUT SLOWER DEVELOPMENT OF
SECONDARY LOW PRESSURE MAY BE A LIMITING FACTOR.  REGARDLESS...
EXPECT 1 TO 3 INCHES OF RAIN.  WILL CONTINUE TO MENTION A SLIGHT
CHANCE OF THUNDER WITH SHOWALTER INDICES NEAR ZERO.

THE BULK OF THE RAIN SHOULD COME TO AN END CHRISTMAS MORNING WITH
TEMPS PROBABLY AROUND 60 FOR MUCH OF THE REGION.  WHILE GUSTY
SOUTHERLY WINDS ARE EXPECTED WED NIGHT...INVERSION AND WEAKER LOW
LEVEL JET WILL PROBABLY KEEP MOST AREAS BELOW ADVISORY CRITERIA.
STILL HAVE TO WATCH FOR A SMALL WINDOW ON THE COASTAL PLAIN ESP IF
TEMPS CAN EXCEED 60...BUT HIGHER CONFIDENCE IN WIND ON CHRISTMAS
AFTERNOON AND EVENING BEHIND THE SYSTEM.  INCREASING WESTERLY WIND
ALOFT AND STEEPENING LAPSE RATES WILL BRING THE POTENTIAL FOR THESE
WINDS.  DECENT SHOT AT A PERIOD OF 35 TO 50 MPH GUSTS BEHIND THIS
SYSTEM CHRISTMAS AFTERNOON AND EVENING.  WHILE THE GFS IS AN
OUTLIER...IT WOULD EVEN SUGGEST THE POTENTIAL FOR HIGH WIND CRITERIA
TO BE MET WITH 70 KNOTS AT 850 MB.  THAT MAY BE OVERDONE...BUT
SOMETHING WILL HAVE TO KEEP AN EYE ON THE NEXT FEW DAYS.

FRIDAY AND SATURDAY...

UPPER LEVEL RIDGE OFF THE SOUTHEAST COAST WILL KEEP KEEP US IN MILD
SOUTHWEST FLOW ALOFT.  DRY WEATHER EXPECTED WITH FORCING FOR ANY
PRECIPITATION WILL TO OUR NORTHWEST.  HIGHS MAINLY IN THE 40S TO
LOWER 50S.

SUNDAY...

CONFIDENCE IN THE FORECAST GOES DOWN CONSIDERABLY OVER THIS TIME.
DEVELOPING UPPER LEVEL RIDGING INTO ALASKA WILL SEND THE POLAR JET
SOUTHWARD INTO THE CENTRAL U.S.  AT THE SAME TIME...UPPER LEVEL
RIDGE OFF THE SOUTHEAST COAST WILL TRY TO HANG TOUGH.  THE GFS
INSISTS ON DRY AND COLDER WEATHER ARRIVING...BUT WERE NOT CONVINCED.
GIVEN THE SOUTHEAST RIDGE...IT MAY HOLD THE COLD AIR UP AND ALLOW
DEVELOPING LOW PRESSURE TO TRACK NEAR NEW ENGLAND SUN AND SUN NIGHT.
THIS COULD BRING RAIN OR SNOW DEPENDING ON ITS TRACK...OBVIOUSLY A
WEEK OUT SO PLENTY OF UNCERTAINTY BUT WOULD LEAN TOWARDS ANOTHER
SYSTEM AND AWAY FROM THE DRY GFS.

&&

.AVIATION /12Z MONDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /THROUGH TUESDAY/...

7 AM UPDATE...

TODAY...HIGH CONFIDENCE. MAINLY MVFR CONDITIONS BUT SOME LOCALIZED
IFR CONDITIONS POSSIBLE ALONG THE COAST AND WORCESTER HILLS.  A FEW
SHOWERS EXPECTED ALONG EASTERN MA COAST WITH PERHAPS A PASSING
FLURRY/SNOW SHOWER OR TWO ACROSS THE INTERIOR.

TONIGHT...MODERATE CONFIDENCE. MAINLY MVFR CONDITIONS CONTINUE IN
SCATTERED LIGHT SNOW SHOWERS. LIGHT FZRA POSSIBLE LATE MONDAY NIGHT
ACROSS NW MASSACHUSETTS.

TUESDAY...MODERATE CONFIDENCE. MVFR CONDITIONS MAY DROP TO IFR
WITHIN AND HEAVY RAIN FALL. VSBYS WILL BE REDUCED TO 5SM OR LESS
AS WELL.

KBOS TERMINAL...MODERATE CONFIDENCE.

KBDL TERMINAL...MODERATE CONFIDENCE.

OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY...

TUESDAY NIGHT INTO THURSDAY MORNING...MODERATE CONFIDENCE.
WIDESPREAD LOW END MVFR TO IFR CONDITIONS EXPECTED IN PERIODS OF
HEAVY SHOWERS/LOW CLOUDS AND FOG PATCHES.  A PERIOD OF SOUTHERLY
WIND GUSTS OF 30 TO 40 KNOTS EXPECTED ON THE COASTAL PLAIN WED
NIGHT.  LLWS ALSO A CONCERN FOR THE ENTIRE REGION WED INTO EARLY THU.

THURSDAY AFTERNOON INTO FRIDAY...MODERATE TO HIGH CONFIDENCE IN
MAINLY VFR.  HOWEVER...A PERIOD OF WESTERLY 30 TO 45 KNOT WIND GUSTS
POSSIBLE THU AFTERNOON AND EVENING.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /THROUGH TUESDAY/...MODERATE TO HIGH CONFIDENCE.

HIGH PRESSURE ACROSS QUEBEC AND THE MARITIMES WILL RESULT IN
PERSISTENT NORTHEASTERLY TO EASTERLY WINDS ACROSS THE WATERS THROUGH
TODAY. THIS WILL BUILD SEAS TO 5FT ON THE EASTERN WATERS DESPITE
WIND GUSTS UP TO 20 KNOTS. HAVE CONTINUED SCA.

APPROACHING SURFACE LOW PRESSURE FROM THE MID-ATLANTIC TONIGHT WILL
HELP INCREASE AN EASTERLY LLJ OVER THE WATER TOMORROW. THIS WILL
BUILD THE SEAS BETWEEN 5-8 FT. COULD SEE WIND GUSTS BETWEEN 20-30
KTS AS THE FRONT PASSES. SCA HAS BEEN EXPANDED ACCORDINGLY.

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

TUESDAY NIGHT...LONG FETCH EASTERLY FLOW WILL CONTINUE TO RESULT IN
SCA SEAS ACROSS THE OUTER-WATERS WITH HIGH PRESSURE MOVING EAST OF
THE CANADIAN MARITIMES.  WINDS SHOULD GENERALLY BE BELOW SMALL CRAFT
THRESHOLDS.

WEDNESDAY INTO EARLY THURSDAY...INTENSIFYING LOW PRESSURE PASSING
WELL TO OUR WEST WILL CAUSE WINDS TO TURN SOUTHERLY AND BECOME
GUSTY. SMALL CRAFT WIND GUSTS ARE A LOCK.  THE MAIN UNCERTAINTY IS
DO WE SEE SOUTHERLY GALES DEVELOP WED NIGHT.  STRONG LOW LEVEL JET
PRESENT...BUT WE WILL BE DEALING WITH AN INVERSION OVER THE
RELATIVELY COOL OCEAN.  REGARDLESS...STILL SHOULD SEE AT LEAST A
PERIOD OF NEAR GALE FORCE SOUTHERLY WIND GUSTS.

LATER THURSDAY INTO FRIDAY...A PERIOD OF WESTERLY GALE FORCE WIND
GUSTS APPEARS LIKELY IN THE COLD ADVECTION PATTERN BEHIND THE STORM
THU AFTERNOON AND NIGHT.  WINDS SHOULD DIMINISH SOME ON FRIDAY.

&&

.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES OCCUR TUE AND WED.

EAST MASSACHUSETTS COAST:

TUESDAY...HIGH TIDE AT BOSTON WILL BE 11.6 FT AT MIDDAY. WINDS WILL
BE FROM THE EAST AT 10 TO 15 KNOTS...SO THERE WILL BE ONSHORE FLOW
DURING THIS HIGH TIDE.  WHILE THIS IS NOTHING TOO STRONG...GIVEN THE
HIGH ASTRO TIDE EXPECT SOME SPLASH OVER/MINOR COASTAL FLOODING.
CERTAINLY DO NOT EXPECT TO SEE ANY SIGNIFICANT ISSUES.

WEDNESDAY...HIGH TIDE AT BOSTON WILL BE 11.7 FT AT MIDDAY.  WINDS
WILL BE FROM THE SOUTHEAST NEAR 10 KNOTS BUT THERE WILL BE SOME
PRESSURE FALLS WITH INTENSIFYING LOW PRESSURE TO OUR WEST.  THIS
SHOULD BE ENOUGH FOR MORE SPLASH OVER/MINOR COASTAL FLOODING WITH
THE HIGH ASTRO TIDES.  HOWEVER...DO NOT EXPECT ANY SIGNIFICANT
PROBLEMS GIVEN WINDS/SEAS SHOULD BE HELD IN CHECK DURING THE TIME OF
HIGH TIDE.

SOUTH COAST:

WEDNESDAY EVENING...SOUTHERLY WINDS ARE EXPECTED AND ASTRONOMICAL
TIDES INCREASE ALONG THE SOUTH COAST. HIGH TIDE IN PROVIDENCE WILL
BE 5.2 FT THAT EVENING. 925 MB LLJ STRENGTHENS TO 55-65 KTS WHICH
COULD PUSH A 1 TO 2 FOOT SURGE UP ALONG THE SOUTH COAST DURING THE
TIME OF HIGH TIDE.  THE LOW LEVEL INVERSION WILL PROBABLY HOLD THE
STRONGEST WINDS JUST ABOVE THE GROUND...SO THINKING THE RISK IS FOR
SPLASH OVER AND MINOR COASTAL FLOODING.  THERE STILL IS A LOW RISK
FOR MODERATE COASTAL FLOODING...BUT THAT IS OFTEN HARD TO GET IN A
NON-TROPICAL SYSTEM ALONG THE SOUTH COAST.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 1 AM TO 7 PM EST TUESDAY FOR ANZ231-
     232-251-256.
     SMALL CRAFT ADVISORY FROM 1 PM THIS AFTERNOON TO 7 PM EST
     TUESDAY FOR ANZ250-254.
     SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 7 PM EST
     TUESDAY FOR ANZ255.

&&

$$
SYNOPSIS...FRANK/DUNTEN
NEAR TERM...FRANK/DUNTEN
SHORT TERM...DUNTEN
LONG TERM...FRANK
AVIATION...FRANK/DUNTEN
MARINE...DUNTEN/FRANK
TIDES/COASTAL FLOODING...FRANK




000
FXUS61 KBOX 221201
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
700 AM EST MON DEC 22 2014

.SYNOPSIS...

A WAVE OF LOW PRESSURE WILL BRING PERIODS OF WET WEATHER MAINLY LATE
TONIGHT INTO TUESDAY NIGHT...WHICH MAY BEGIN AS A BRIEF PERIOD OF
FROZEN PRECIPITATION ACROSS NORTHWEST AND NORTH CENTRAL
MASSACHUSETTS.  A MUCH STRONGER STORM PASSING WELL TO OUR WEST
WEDNESDAY INTO CHRISTMAS MORNING WILL BRING HEAVY RAIN...GUSTY WINDS
AND PROBABLY MINOR COASTAL FLOODING.  DRY WEATHER WITH ABOVE NORMAL
TEMPERATURES EXPECTED CHRISTMAS AFTERNOON INTO SATURDAY.  LOW
PRESSURE MAY BRING A RETURN TO UNSETTLED WEATHER BY NEXT SUNDAY.

&&

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

7 AM UPDATE...

DESPITE UPPER LEVEL RIDGING ALOFT...EAST TO SOUTHEAST FLOW JUST OFF
THE DECK WAS ENOUGH TO RESULT IN LOW LEVEL LIFT FOR SCATTERED RAIN
SHOWERS JUST EAST OF THE MA COAST.  BASED ON RADAR IMAGERY AND
LATEST MESOSCALE MODELS...OPTED TO INCREASE POPS TODAY
ACROSS EASTERN NEW ENGLAND FOR SCATTERED SHOWERS.  PTYPE...ON
EASTERN MA COAST MAINLY RAIN SHOWERS BUT A FEW FLAKES COULD MIX IN
ACROSS NORTHEAST MA THIS MORNING. FURTHER INLAND...ACROSS THE
INTERIOR IT WILL BE COLD ENOUGH FOR A FEW SNOW SHOWERS/FLURRIES BUT
MAIN FOCUS WILL BE ON THE EASTERN MA COAST. THEREFORE...JUST
EXPECT A FEW SNOW SHOWERS/FLURRIES AND MUCH OF THE DAY WILL BE DRY
ACROSS THE INTERIOR.

AS FOR HIGH TEMPS...LOW LEVEL NORTHEAST FLOW AND CLOUDY SKIES
PROBABLY KEEP HIGHS IN THE MIDDLE 30S ACROSS THE INTERIOR. ONSHORE
FLOW WILL ALLOW COASTAL LOCATIONS TO SEE HIGHS IN THE UPPER
30S TO THE LOWER 40S...WITH EVEN MIDDLE 40S ON CAPE AND ISLANDS.

&&

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

*LIGHT FREEZING RAIN IS POSSIBLE ACROSS THE INTERIOR NORTHWEST AND
  NORTHERN WORCESTER HILLS*

A WEAK AREA OF LOW PRESSURE DEVELOPS ALONG A WARM FRONT OFF THE MID
ATLANTIC...DRIFTING NORTHWARD TOWARD THE AREA. THIS LOW REMAINS WEAK
AS THE WARM FRONT MOVES SLOWLY NORTHWARD TONIGHT INTO TOMORROW.
DECENT WARM ADVECTION AHEAD OF THIS WAVE WITH SEVERAL HI-RES
GUIDANCE MODELS SHOWS A POTENTIAL FOR COLD AIR DAMMING ACROSS THE
INTERIOR INTO TUESDAY MORNING.  BIGGEST QUESTION WILL BE THE
MOISTURE POTENTIAL...IS THERE ENOUGH TO DEVELOP PRECIP ESP TONIGHT?
GUIDANCE DOES SHOW ENOUGH LIFT AHEAD OF APPROACHING SURFACE LOW PER
THE GFS/EC SO ANTICIPATE PRECIP TO DEVELOP AND OVERSPREAD ACROSS
SOUTHERN NEW ENGLAND. IF THIS PLAYS OUT WITH COLD AIR DAMMING AND
WARM AIR ADVECTION...THEN WE COULD SEE FREEZING RAIN/DRIZZLE ACROSS
THE INTERIOR NORTHWEST AND NORTHERN WORCESTER HILLS VERY LATE
TONIGHT INTO TUESDAY MORNING. A WINTER WEATHER ADVISORY MAY BE
NEEDED.

AS SURFACE LOW CONTINUES TO MOVE NORTHWARD...AND HIGH PRESSURE OVER
EASTERN CANADA...ANTICIPATE AN INCREASING LLJ. THIS SOUTHEASTERLY
JET WILL CONTINUE TO FEED MOISTURE INTO THE REGION AND WITH
SOUNDINGS SHOW A VERY SATURATED PROFILE COULD SEE NUMEROUS SHOWERS
WITH PERHAPS A FEW HEAVY DOWNPOURS. NOTICED GUIDANCE HAS
INCREASED THE QPF OVER THE PAST FEW DAYS. AS THE WEAK SURFACE LOW
MOVES NORTH OF SOUTHERN NEW ENGLAND...WARM FRONT WILL LIFT
NORTHWARD SO ALL PRECIP BY THE LATE MORNING WILL BE IN THE LIQUID
FORM.

WE COULD ALSO SEE SOME MINOR COASTAL FLOODING CONCERNS ON TUESDAY
WITH DUE EASTERLY FLOW INCREASING TO ABOUT 20 TO 25 MPH.  SEE BELOW
FOR MORE DETAILS.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
HIGHLIGHTS...

* PERIODS OF RAIN TUE NIGHT INTO XMAS MORNING WILL BE HEAVY AT TIMES
* DRY BY CHRISTMAS AFTERNOON BUT WINDY
* TEMPS AROUND 60 FOR SOME LATE WED INTO CHRISTMAS MORNING
* DRY BUT ABOVE NORMAL TEMPS CONTINUE FRI AND SAT
* UNSETTLED WEATHER MAY RETURN BY SUN BUT LOW CONFIDENCE

DETAILS...

TUESDAY NIGHT INTO CHRISTMAS...

STRONG SHORTWAVE WILL DIG ACROSS THE CENTRAL U.S. AND ALLOW DEEP
SOUTH TO SOUTHWEST FLOW ALOFT ACROSS SOUTHERN NEW ENGLAND.  THIS
WILL SEND AND ANOMALOUS MILD AIRMASS INTO SOUTHERN NEW ENGLAND FOR
LATE DECEMBER.  GEFS SHOWING PWATS 4 TO 5 STANDARD DEVIATIONS ABOVE
NORMAL BY WED NIGHT ACROSS OUR REGION.  WHILE HEAVY RAIN IS STILL
EXPECTED...THE MODELS HAVE CUT DOWN ON THE QPF IN THE LAST FEW RUNS.
THE MAIN LOW STILL PASSES WELL TO OUR WEST ACROSS GREAT LAKES...BUT
THEIR SLOWER AND WEAKER WITH SECONDARY DEVELOPMENT ACROSS OUR
REGION.  THIS RESULTS IN A WEAKER LOW LEVEL JET...HENCE LESS QPF.
GIVEN ANOMALOUS PWATS IN PLACE...DO NOT WANT TO COMPLETELY LET OUR
GUARD DOWN WITH THE POTENTIAL FOR FLOODING...BUT DOES APPEAR
SOMEWHAT LESS OF A RISK THAN YESTERDAY.  NONETHELESS...STILL EXPECT
TYPICAL NUISANCE POOR DRAINAGE STREET FLOODING.

AS FOR TIMING...SOUTHERLY FLOW ALOFT WILL RESULT IN SCATTERED
SHOWERS TUE NIGHT.  BULK OF THE RAIN WILL OCCUR WED INTO EARLY
CHRISTMAS DAY WHEN STRONGEST FORCING COINCIDES HIGH PWAT AIRMASS.
SOME OF THIS RAIN WILL BE HEAVY AT TIMES MAY RESULT IN NUISANCE POOR
DRAINAGE STREET FLOODING.  STILL A LOW RISK FOR MORE SIGNIFICANT
FLOODING GIVEN EXTREMELY HIGH PWATS...BUT SLOWER DEVELOPMENT OF
SECONDARY LOW PRESSURE MAY BE A LIMITING FACTOR.  REGARDLESS...
EXPECT 1 TO 3 INCHES OF RAIN.  WILL CONTINUE TO MENTION A SLIGHT
CHANCE OF THUNDER WITH SHOWALTER INDICES NEAR ZERO.

THE BULK OF THE RAIN SHOULD COME TO AN END CHRISTMAS MORNING WITH
TEMPS PROBABLY AROUND 60 FOR MUCH OF THE REGION.  WHILE GUSTY
SOUTHERLY WINDS ARE EXPECTED WED NIGHT...INVERSION AND WEAKER LOW
LEVEL JET WILL PROBABLY KEEP MOST AREAS BELOW ADVISORY CRITERIA.
STILL HAVE TO WATCH FOR A SMALL WINDOW ON THE COASTAL PLAIN ESP IF
TEMPS CAN EXCEED 60...BUT HIGHER CONFIDENCE IN WIND ON CHRISTMAS
AFTERNOON AND EVENING BEHIND THE SYSTEM.  INCREASING WESTERLY WIND
ALOFT AND STEEPENING LAPSE RATES WILL BRING THE POTENTIAL FOR THESE
WINDS.  DECENT SHOT AT A PERIOD OF 35 TO 50 MPH GUSTS BEHIND THIS
SYSTEM CHRISTMAS AFTERNOON AND EVENING.  WHILE THE GFS IS AN
OUTLIER...IT WOULD EVEN SUGGEST THE POTENTIAL FOR HIGH WIND CRITERIA
TO BE MET WITH 70 KNOTS AT 850 MB.  THAT MAY BE OVERDONE...BUT
SOMETHING WILL HAVE TO KEEP AN EYE ON THE NEXT FEW DAYS.

FRIDAY AND SATURDAY...

UPPER LEVEL RIDGE OFF THE SOUTHEAST COAST WILL KEEP KEEP US IN MILD
SOUTHWEST FLOW ALOFT.  DRY WEATHER EXPECTED WITH FORCING FOR ANY
PRECIPITATION WILL TO OUR NORTHWEST.  HIGHS MAINLY IN THE 40S TO
LOWER 50S.

SUNDAY...

CONFIDENCE IN THE FORECAST GOES DOWN CONSIDERABLY OVER THIS TIME.
DEVELOPING UPPER LEVEL RIDGING INTO ALASKA WILL SEND THE POLAR JET
SOUTHWARD INTO THE CENTRAL U.S.  AT THE SAME TIME...UPPER LEVEL
RIDGE OFF THE SOUTHEAST COAST WILL TRY TO HANG TOUGH.  THE GFS
INSISTS ON DRY AND COLDER WEATHER ARRIVING...BUT WERE NOT CONVINCED.
GIVEN THE SOUTHEAST RIDGE...IT MAY HOLD THE COLD AIR UP AND ALLOW
DEVELOPING LOW PRESSURE TO TRACK NEAR NEW ENGLAND SUN AND SUN NIGHT.
THIS COULD BRING RAIN OR SNOW DEPENDING ON ITS TRACK...OBVIOUSLY A
WEEK OUT SO PLENTY OF UNCERTAINTY BUT WOULD LEAN TOWARDS ANOTHER
SYSTEM AND AWAY FROM THE DRY GFS.

&&

.AVIATION /12Z MONDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /THROUGH TUESDAY/...

7 AM UPDATE...

TODAY...HIGH CONFIDENCE. MAINLY MVFR CONDITIONS BUT SOME LOCALIZED
IFR CONDITIONS POSSIBLE ALONG THE COAST AND WORCESTER HILLS.  A FEW
SHOWERS EXPECTED ALONG EASTERN MA COAST WITH PERHAPS A PASSING
FLURRY/SNOW SHOWER OR TWO ACROSS THE INTERIOR.

TONIGHT...MODERATE CONFIDENCE. MAINLY MVFR CONDITIONS CONTINUE IN
SCATTERED LIGHT SNOW SHOWERS. LIGHT FZRA POSSIBLE LATE MONDAY NIGHT
ACROSS NW MASSACHUSETTS.

TUESDAY...MODERATE CONFIDENCE. MVFR CONDITIONS MAY DROP TO IFR
WITHIN AND HEAVY RAIN FALL. VSBYS WILL BE REDUCED TO 5SM OR LESS
AS WELL.

KBOS TERMINAL...MODERATE CONFIDENCE.

KBDL TERMINAL...MODERATE CONFIDENCE.

OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY...

TUESDAY NIGHT INTO THURSDAY MORNING...MODERATE CONFIDENCE.
WIDESPREAD LOW END MVFR TO IFR CONDITIONS EXPECTED IN PERIODS OF
HEAVY SHOWERS/LOW CLOUDS AND FOG PATCHES.  A PERIOD OF SOUTHERLY
WIND GUSTS OF 30 TO 40 KNOTS EXPECTED ON THE COASTAL PLAIN WED
NIGHT.  LLWS ALSO A CONCERN FOR THE ENTIRE REGION WED INTO EARLY THU.

THURSDAY AFTERNOON INTO FRIDAY...MODERATE TO HIGH CONFIDENCE IN
MAINLY VFR.  HOWEVER...A PERIOD OF WESTERLY 30 TO 45 KNOT WIND GUSTS
POSSIBLE THU AFTERNOON AND EVENING.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /THROUGH TUESDAY/...MODERATE TO HIGH CONFIDENCE.

HIGH PRESSURE ACROSS QUEBEC AND THE MARITIMES WILL RESULT IN
PERSISTENT NORTHEASTERLY TO EASTERLY WINDS ACROSS THE WATERS THROUGH
TODAY. THIS WILL BUILD SEAS TO 5FT ON THE EASTERN WATERS DESPITE
WIND GUSTS UP TO 20 KNOTS. HAVE CONTINUED SCA.

APPROACHING SURFACE LOW PRESSURE FROM THE MID-ATLANTIC TONIGHT WILL
HELP INCREASE AN EASTERLY LLJ OVER THE WATER TOMORROW. THIS WILL
BUILD THE SEAS BETWEEN 5-8 FT. COULD SEE WIND GUSTS BETWEEN 20-30
KTS AS THE FRONT PASSES. SCA HAS BEEN EXPANDED ACCORDINGLY.

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

TUESDAY NIGHT...LONG FETCH EASTERLY FLOW WILL CONTINUE TO RESULT IN
SCA SEAS ACROSS THE OUTER-WATERS WITH HIGH PRESSURE MOVING EAST OF
THE CANADIAN MARITIMES.  WINDS SHOULD GENERALLY BE BELOW SMALL CRAFT
THRESHOLDS.

WEDNESDAY INTO EARLY THURSDAY...INTENSIFYING LOW PRESSURE PASSING
WELL TO OUR WEST WILL CAUSE WINDS TO TURN SOUTHERLY AND BECOME
GUSTY. SMALL CRAFT WIND GUSTS ARE A LOCK.  THE MAIN UNCERTAINTY IS
DO WE SEE SOUTHERLY GALES DEVELOP WED NIGHT.  STRONG LOW LEVEL JET
PRESENT...BUT WE WILL BE DEALING WITH AN INVERSION OVER THE
RELATIVELY COOL OCEAN.  REGARDLESS...STILL SHOULD SEE AT LEAST A
PERIOD OF NEAR GALE FORCE SOUTHERLY WIND GUSTS.

LATER THURSDAY INTO FRIDAY...A PERIOD OF WESTERLY GALE FORCE WIND
GUSTS APPEARS LIKELY IN THE COLD ADVECTION PATTERN BEHIND THE STORM
THU AFTERNOON AND NIGHT.  WINDS SHOULD DIMINISH SOME ON FRIDAY.

&&

.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES OCCUR TUE AND WED.

EAST MASSACHUSETTS COAST:

TUESDAY...HIGH TIDE AT BOSTON WILL BE 11.6 FT AT MIDDAY. WINDS WILL
BE FROM THE EAST AT 10 TO 15 KNOTS...SO THERE WILL BE ONSHORE FLOW
DURING THIS HIGH TIDE.  WHILE THIS IS NOTHING TOO STRONG...GIVEN THE
HIGH ASTRO TIDE EXPECT SOME SPLASH OVER/MINOR COASTAL FLOODING.
CERTAINLY DO NOT EXPECT TO SEE ANY SIGNIFICANT ISSUES.

WEDNESDAY...HIGH TIDE AT BOSTON WILL BE 11.7 FT AT MIDDAY.  WINDS
WILL BE FROM THE SOUTHEAST NEAR 10 KNOTS BUT THERE WILL BE SOME
PRESSURE FALLS WITH INTENSIFYING LOW PRESSURE TO OUR WEST.  THIS
SHOULD BE ENOUGH FOR MORE SPLASH OVER/MINOR COASTAL FLOODING WITH
THE HIGH ASTRO TIDES.  HOWEVER...DO NOT EXPECT ANY SIGNIFICANT
PROBLEMS GIVEN WINDS/SEAS SHOULD BE HELD IN CHECK DURING THE TIME OF
HIGH TIDE.

SOUTH COAST:

WEDNESDAY EVENING...SOUTHERLY WINDS ARE EXPECTED AND ASTRONOMICAL
TIDES INCREASE ALONG THE SOUTH COAST. HIGH TIDE IN PROVIDENCE WILL
BE 5.2 FT THAT EVENING. 925 MB LLJ STRENGTHENS TO 55-65 KTS WHICH
COULD PUSH A 1 TO 2 FOOT SURGE UP ALONG THE SOUTH COAST DURING THE
TIME OF HIGH TIDE.  THE LOW LEVEL INVERSION WILL PROBABLY HOLD THE
STRONGEST WINDS JUST ABOVE THE GROUND...SO THINKING THE RISK IS FOR
SPLASH OVER AND MINOR COASTAL FLOODING.  THERE STILL IS A LOW RISK
FOR MODERATE COASTAL FLOODING...BUT THAT IS OFTEN HARD TO GET IN A
NON-TROPICAL SYSTEM ALONG THE SOUTH COAST.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 1 AM TO 7 PM EST TUESDAY FOR ANZ231-
     232-251-256.
     SMALL CRAFT ADVISORY FROM 1 PM THIS AFTERNOON TO 7 PM EST
     TUESDAY FOR ANZ250-254.
     SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 7 PM EST
     TUESDAY FOR ANZ255.

&&

$$
SYNOPSIS...FRANK/DUNTEN
NEAR TERM...FRANK/DUNTEN
SHORT TERM...DUNTEN
LONG TERM...FRANK
AVIATION...FRANK/DUNTEN
MARINE...DUNTEN/FRANK
TIDES/COASTAL FLOODING...FRANK





000
FXUS61 KBOX 220938
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
437 AM EST MON DEC 22 2014

.SYNOPSIS...

A WAVE OF LOW PRESSURE WILL BRING PERIODS OF WET WEATHER MAINLY LATE
TONIGHT INTO TUESDAY NIGHT...WHICH MAY BEGIN AS A BRIEF PERIOD OF
FROZEN PRECIPITATION ACROSS NORTHWEST AND NORTH CENTRAL
MASSACHUSETTS.  A MUCH STRONGER STORM PASSING WELL TO OUR WEST
WEDNESDAY INTO CHRISTMAS MORNING WILL BRING HEAVY RAIN...GUSTY WINDS
AND PROBABLY MINOR COASTAL FLOODING.  DRY WEATHER WITH ABOVE NORMAL
TEMPERATURES EXPECTED CHRISTMAS AFTERNOON INTO SATURDAY.  LOW
PRESSURE MAY BRING A RETURN TO UNSETTLED WEATHER BY NEXT SUNDAY.

&&

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

UPPER LEVEL RIDGE BUILDS AHEAD OF DIGGING MIDWEST TROUGH WITH
HIGH PRESSURE REMAINING ANCHORED OVER THE CANADIAN MARITIMES
THROUGH TONIGHT.

EASTERLY FLOW WILL CONTINUE ONSHORE ALLOWING FOR THE PROFILE TO
CONTINUE TO MOISTEN IN THE LOW LEVELS. IF THIS MOISTURE DEEPENS
ENOUGH THEN WE COULD SEE LIGHT SHOWERS DEVELOP ESP ACROSS THE MASS
EAST COASTLINE. OTHERWISE DRIZZLE MAY BE THE MAIN FACTOR AS THE
UPPER LEVELS ARE FAIRLY DRY. OVERALL TODAY WILL BE A COOL AND CLOUDY
DAY WITH HIGHS ONLY REACHING IN THE UPPER 30S TO LOW 40S AS CROSS
SECTIONS ARE VERY MOIST IN THE LOW LEVELS.

&&

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

TONIGHT INTO TOMORROW...

*LIGHT FREEZING RAIN IS POSSIBLE ACROSS THE INTERIOR NORTHWEST AND
  NORTHERN WORCESTER HILLS*

A WEAK AREA OF LOW PRESSURE DEVELOPS ALONG A WARM FRONT OFF THE MID
ATLANTIC...DRIFTING NORTHWARD TOWARD THE AREA. THIS LOW REMAINS WEAK
AS THE WARM FRONT MOVES SLOWLY NORTHWARD TONIGHT INTO TOMORROW.
DECENT WARM ADVECTION AHEAD OF THIS WAVE WITH SEVERAL HI-RES
GUIDANCE MODELS SHOWS A POTENTIAL FOR COLD AIR DAMMING ACROSS THE
INTERIOR INTO TUESDAY MORNING.  BIGGEST QUESTION WILL BE THE
MOISTURE POTENTIAL...IS THERE ENOUGH TO DEVELOP PRECIP ESP TONIGHT?
GUIDANCE DOES SHOW ENOUGH LIFT AHEAD OF APPROACHING SURFACE LOW PER
THE GFS/EC SO ANTICIPATE PRECIP TO DEVELOP AND OVERSPREAD ACROSS
SOUTHERN NEW ENGLAND. IF THIS PLAYS OUT WITH COLD AIR DAMMING AND
WARM AIR ADVECTION...THEN WE COULD SEE FREEZING RAIN/DRIZZLE ACROSS
THE INTERIOR NORTHWEST AND NORTHERN WORCESTER HILLS VERY LATE
TONIGHT INTO TUESDAY MORNING. A WINTER WEATHER ADVISORY MAY BE
NEEDED.

AS SURFACE LOW CONTINUES TO MOVE NORTHWARD...AND HIGH PRESSURE OVER
EASTERN CANADA...ANTICIPATE AN INCREASING LLJ. THIS SOUTHEASTERLY
JET WILL CONTINUE TO FEED MOISTURE INTO THE REGION AND WITH
SOUNDINGS SHOW A VERY SATURATED PROFILE COULD SEE NUMEROUS SHOWERS
WITH PERHAPS A FEW HEAVY DOWNPOURS. NOTICED GUIDANCE HAS
INCREASED THE QPF OVER THE PAST FEW DAYS. AS THE WEAK SURFACE LOW
MOVES NORTH OF SOUTHERN NEW ENGLAND...WARM FRONT WILL LIFT
NORTHWARD SO ALL PRECIP BY THE LATE MORNING WILL BE IN THE LIQUID
FORM.

WE COULD ALSO SEE SOME MINOR COASTAL FLOODING CONCERNS ON TUESDAY
WITH DUE EASTERLY FLOW INCREASING TO ABOUT 20 TO 25 MPH.  SEE BELOW
FOR MORE DETAILS.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...

HIGHLIGHTS...

* PERIODS OF RAIN TUE NIGHT INTO XMAS MORNING WILL BE HEAVY AT TIMES
* DRY BY CHRISTMAS AFTERNOON BUT WINDY
* TEMPS AROUND 60 FOR SOME LATE WED INTO CHRISTMAS MORNING
* DRY BUT ABOVE NORMAL TEMPS CONTINUE FRI AND SAT
* UNSETTLED WEATHER MAY RETURN BY SUN BUT LOW CONFIDENCE

DETAILS...

TUESDAY NIGHT INTO CHRISTMAS...

STRONG SHORTWAVE WILL DIG ACROSS THE CENTRAL U.S. AND ALLOW DEEP
SOUTH TO SOUTHWEST FLOW ALOFT ACROSS SOUTHERN NEW ENGLAND.  THIS
WILL SEND AND ANOMALOUS MILD AIRMASS INTO SOUTHERN NEW ENGLAND FOR
LATE DECEMBER.  GEFS SHOWING PWATS 4 TO 5 STANDARD DEVIATIONS ABOVE
NORMAL BY WED NIGHT ACROSS OUR REGION.  WHILE HEAVY RAIN IS STILL
EXPECTED...THE MODELS HAVE CUT DOWN ON THE QPF IN THE LAST FEW RUNS.
THE MAIN LOW STILL PASSES WELL TO OUR WEST ACROSS GREAT LAKES...BUT
THEIR SLOWER AND WEAKER WITH SECONDARY DEVELOPMENT ACROSS OUR
REGION.  THIS RESULTS IN A WEAKER LOW LEVEL JET...HENCE LESS QPF.
GIVEN ANOMALOUS PWATS IN PLACE...DO NOT WANT TO COMPLETELY LET OUR
GUARD DOWN WITH THE POTENTIAL FOR FLOODING...BUT DOES APPEAR
SOMEWHAT LESS OF A RISK THAN YESTERDAY.  NONETHELESS...STILL EXPECT
TYPICAL NUISANCE POOR DRAINAGE STREET FLOODING.

AS FOR TIMING...SOUTHERLY FLOW ALOFT WILL RESULT IN SCATTERED
SHOWERS TUE NIGHT.  BULK OF THE RAIN WILL OCCUR WED INTO EARLY
CHRISTMAS DAY WHEN STRONGEST FORCING COINCIDES HIGH PWAT AIRMASS.
SOME OF THIS RAIN WILL BE HEAVY AT TIMES MAY RESULT IN NUISANCE POOR
DRAINAGE STREET FLOODING.  STILL A LOW RISK FOR MORE SIGNIFICANT
FLOODING GIVEN EXTREMELY HIGH PWATS...BUT SLOWER DEVELOPMENT OF
SECONDARY LOW PRESSURE MAY BE A LIMITING FACTOR.  REGARDLESS...
EXPECT 1 TO 3 INCHES OF RAIN.  WILL CONTINUE TO MENTION A SLIGHT
CHANCE OF THUNDER WITH SHOWALTER INDICES NEAR ZERO.

THE BULK OF THE RAIN SHOULD COME TO AN END CHRISTMAS MORNING WITH
TEMPS PROBABLY AROUND 60 FOR MUCH OF THE REGION.  WHILE GUSTY
SOUTHERLY WINDS ARE EXPECTED WED NIGHT...INVERSION AND WEAKER LOW
LEVEL JET WILL PROBABLY KEEP MOST AREAS BELOW ADVISORY CRITERIA.
STILL HAVE TO WATCH FOR A SMALL WINDOW ON THE COASTAL PLAIN ESP IF
TEMPS CAN EXCEED 60...BUT HIGHER CONFIDENCE IN WIND ON CHRISTMAS
AFTERNOON AND EVENING BEHIND THE SYSTEM.  INCREASING WESTERLY WIND
ALOFT AND STEEPENING LAPSE RATES WILL BRING THE POTENTIAL FOR THESE
WINDS.  DECENT SHOT AT A PERIOD OF 35 TO 50 MPH GUSTS BEHIND THIS
SYSTEM CHRISTMAS AFTERNOON AND EVENING.  WHILE THE GFS IS AN
OUTLIER...IT WOULD EVEN SUGGEST THE POTENTIAL FOR HIGH WIND CRITERIA
TO BE MET WITH 70 KNOTS AT 850 MB.  THAT MAY BE OVERDONE...BUT
SOMETHING WILL HAVE TO KEEP AN EYE ON THE NEXT FEW DAYS.

FRIDAY AND SATURDAY...

UPPER LEVEL RIDGE OFF THE SOUTHEAST COAST WILL KEEP KEEP US IN MILD
SOUTHWEST FLOW ALOFT.  DRY WEATHER EXPECTED WITH FORCING FOR ANY
PRECIPITATION WILL TO OUR NORTHWEST.  HIGHS MAINLY IN THE 40S TO
LOWER 50S.

SUNDAY...

CONFIDENCE IN THE FORECAST GOES DOWN CONSIDERABLY OVER THIS TIME.
DEVELOPING UPPER LEVEL RIDGING INTO ALASKA WILL SEND THE POLAR JET
SOUTHWARD INTO THE CENTRAL U.S.  AT THE SAME TIME...UPPER LEVEL
RIDGE OFF THE SOUTHEAST COAST WILL TRY TO HANG TOUGH.  THE GFS
INSISTS ON DRY AND COLDER WEATHER ARRIVING...BUT WERE NOT CONVINCED.
GIVEN THE SOUTHEAST RIDGE...IT MAY HOLD THE COLD AIR UP AND ALLOW
DEVELOPING LOW PRESSURE TO TRACK NEAR NEW ENGLAND SUN AND SUN NIGHT.
THIS COULD BRING RAIN OR SNOW DEPENDING ON ITS TRACK...OBVIOUSLY A
WEEK OUT SO PLENTY OF UNCERTAINTY BUT WOULD LEAN TOWARDS ANOTHER
SYSTEM AND AWAY FROM THE DRY GFS.

&&

.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 /THROUGH TUESDAY/...

TODAY...HIGH CONFIDENCE. DRIZZLE OR A FEW FLURRIES POSSIBLE
ACROSS EAST MASS TERMINALS. OTHERWISE ANY VFR CIGS WILL DROP TO
MVFR CONDITIONS THROUGHOUT THE DAY.

TONIGHT...MODERATE CONFIDENCE. MAINLY MVFR CONDITIONS CONTINUE IN
SCATTERED LIGHT SNOW SHOWERS. LIGHT FZRA POSSIBLE LATE MONDAY NIGHT
ACROSS NW MASSACHUSETTS.

TUESDAY...MODERATE CONFIDENCE. MVFR CONDITIONS MAY DROP TO IFR
WITHIN AND HEAVY RAIN FALL. VSBYS WILL BE REDUCED TO 5SM OR LESS
AS WELL.

KBOS TERMINAL...MODERATE CONFIDENCE. COULD SEE DRIZZLE LATER TODAY.

KBDL TERMINAL...MODERATE CONFIDENCE.

OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY...

TUESDAY NIGHT INTO THURSDAY MORNING...MODERATE CONFIDENCE.
WIDESPREAD LOW END MVFR TO IFR CONDITIONS EXPECTED IN PERIODS OF
HEAVY SHOWERS/LOW CLOUDS AND FOG PATCHES.  A PERIOD OF SOUTHERLY
WIND GUSTS OF 30 TO 40 KNOTS EXPECTED ON THE COASTAL PLAIN WED
NIGHT.  LLWS ALSO A CONCERN FOR THE ENTIRE REGION WED INTO EARLY THU.

THURSDAY AFTERNOON INTO FRIDAY...MODERATE TO HIGH CONFIDENCE IN
MAINLY VFR.  HOWEVER...A PERIOD OF WESTERLY 30 TO 45 KNOT WIND GUSTS
POSSIBLE THU AFTERNOON AND EVENING.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /THROUGH TUESDAY/...MODERATE TO HIGH CONFIDENCE.

HIGH PRESSURE ACROSS QUEBEC AND THE MARITIMES WILL RESULT IN
PERSISTENT NORTHEASTERLY TO EASTERLY WINDS ACROSS THE WATERS THROUGH
TODAY. THIS WILL BUILD SEAS TO 5FT ON THE EASTERN WATERS DESPITE
WIND GUSTS UP TO 20 KNOTS. HAVE CONTINUED SCA.

APPROACHING SURFACE LOW PRESSURE FROM THE MID-ATLANTIC TONIGHT WILL
HELP INCREASE AN EASTERLY LLJ OVER THE WATER TOMORROW. THIS WILL
BUILD THE SEAS BETWEEN 5-8 FT. COULD SEE WIND GUSTS BETWEEN 20-30
KTS AS THE FRONT PASSES. SCA HAS BEEN EXPANDED ACCORDINGLY.

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

TUESDAY NIGHT...LONG FETCH EASTERLY FLOW WILL CONTINUE TO RESULT IN
SCA SEAS ACROSS THE OUTER-WATERS WITH HIGH PRESSURE MOVING EAST OF
THE CANADIAN MARITIMES.  WINDS SHOULD GENERALLY BE BELOW SMALL CRAFT
THRESHOLDS.

WEDNESDAY INTO EARLY THURSDAY...INTENSIFYING LOW PRESSURE PASSING
WELL TO OUR WEST WILL CAUSE WINDS TO TURN SOUTHERLY AND BECOME
GUSTY. SMALL CRAFT WIND GUSTS ARE A LOCK.  THE MAIN UNCERTAINTY IS
DO WE SEE SOUTHERLY GALES DEVELOP WED NIGHT.  STRONG LOW LEVEL JET
PRESENT...BUT WE WILL BE DEALING WITH AN INVERSION OVER THE
RELATIVELY COOL OCEAN.  REGARDLESS...STILL SHOULD SEE AT LEAST A
PERIOD OF NEAR GALE FORCE SOUTHERLY WIND GUSTS.

LATER THURSDAY INTO FRIDAY...A PERIOD OF WESTERLY GALE FORCE WIND
GUSTS APPEARS LIKELY IN THE COLD ADVECTION PATTERN BEHIND THE STORM
THU AFTERNOON AND NIGHT.  WINDS SHOULD DIMINISH SOME ON FRIDAY.

&&

.TIDES/COASTAL FLOODING...


HIGH ASTRONOMICAL TIDES OCCUR TUE AND WED.

EAST MASSACHUSETTS COAST:

TUESDAY...HIGH TIDE AT BOSTON WILL BE 11.6 FT AT MIDDAY. WINDS WILL
BE FROM THE EAST AT 10 TO 15 KNOTS...SO THERE WILL BE ONSHORE FLOW
DURING THIS HIGH TIDE.  WHILE THIS IS NOTHING TOO STRONG...GIVEN THE
HIGH ASTRO TIDE EXPECT SOME SPLASH OVER/MINOR COASTAL FLOODING.
CERTAINLY DO NOT EXPECT TO SEE ANY SIGNIFICANT ISSUES.

WEDNESDAY...HIGH TIDE AT BOSTON WILL BE 11.7 FT AT MIDDAY.  WINDS
WILL BE FROM THE SOUTHEAST NEAR 10 KNOTS BUT THERE WILL BE SOME
PRESSURE FALLS WITH INTENSIFYING LOW PRESSURE TO OUR WEST.  THIS
SHOULD BE ENOUGH FOR MORE SPLASH OVER/MINOR COASTAL FLOODING WITH
THE HIGH ASTRO TIDES.  HOWEVER...DO NOT EXPECT ANY SIGNIFICANT
PROBLEMS GIVEN WINDS/SEAS SHOULD BE HELD IN CHECK DURING THE TIME OF
HIGH TIDE.

SOUTH COAST:

WEDNESDAY EVENING...SOUTHERLY WINDS ARE EXPECTED AND ASTRONOMICAL
TIDES INCREASE ALONG THE SOUTH COAST. HIGH TIDE IN PROVIDENCE WILL
BE 5.2 FT THAT EVENING. 925 MB LLJ STRENGTHENS TO 55-65 KTS WHICH
COULD PUSH A 1 TO 2 FOOT SURGE UP ALONG THE SOUTH COAST DURING THE
TIME OF HIGH TIDE.  THE LOW LEVEL INVERSION WILL PROBABLY HOLD THE
STRONGEST WINDS JUST ABOVE THE GROUND...SO THINKING THE RISK IS FOR
SPLASH OVER AND MINOR COASTAL FLOODING.  THERE STILL IS A LOW RISK
FOR MODERATE COASTAL FLOODING...BUT THAT IS OFTEN HARD TO GET IN A
NON-TROPICAL SYSTEM ALONG THE SOUTH COAST.


&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 1 AM TO 7 PM EST TUESDAY FOR ANZ231-
     232-251-256.
     SMALL CRAFT ADVISORY FROM 1 PM THIS AFTERNOON TO 7 PM EST
     TUESDAY FOR ANZ250-254.
     SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 7 PM EST
     TUESDAY FOR ANZ255.

&&

$$
SYNOPSIS...DUNTEN/FRANK
NEAR TERM...DUNTEN
SHORT TERM...DUNTEN
LONG TERM...FRANK
AVIATION...DUNTEN/FRANK
MARINE...DUNTEN/FRANK
TIDES/COASTAL FLOODING...FRANK




000
FXUS61 KBOX 220927
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
416 AM EST MON DEC 22 2014

.SYNOPSIS...

A WAVE OF LOW PRESSURE WILL BRING THE PERIODS OF WET WEATHER MAINLY
LATE TONIGHT INTO TUESDAY NIGHT...WHICH MAY BEGIN AS A BRIEF PERIOD
OF FROZEN PRECIPITATION ACROSS NORTHWEST MASSACHUSETTS.  A MUCH
STRONGER STORM PASSING WELL TO OUR WEST WEDNESDAY INTO CHRISTMAS
MORNING WILL BRING HEAVY RAIN...GUSTY WINDS AND MINOR COASTAL
FLOODING.  DRY WEATHER WITH ABOVE NORMAL TEMPERATURES EXPECTED
CHRISTMAS AFTERNOON INTO SATURDAY.  LOW PRESSURE MAY BRING A RETURN
TO UNSETTLED WEATHER BY NEXT SUNDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPPER LEVEL RIDGE BUILDS AHEAD OF DIGGING MIDWEST TROUGH WITH
HIGH PRESSURE REMAINING ANCHORED OVER THE CANADIAN MARITIMES
THROUGH TONIGHT.

EASTERLY FLOW WILL CONTINUE ONSHORE ALLOWING FOR THE PROFILE TO
CONTINUE TO MOISTEN IN THE LOW LEVELS. IF THIS MOISTURE DEEPENS
ENOUGH THEN WE COULD SEE LIGHT SHOWERS DEVELOP ESP ACROSS THE MASS
EAST COASTLINE. OTHERWISE DRIZZLE MAY BE THE MAIN FACTOR AS THE
UPPER LEVELS ARE FAIRLY DRY. OVERALL TODAY WILL BE A COOL AND CLOUDY
DAY WITH HIGHS ONLY REACHING IN THE UPPER 30S TO LOW 40S AS CROSS
SECTIONS ARE VERY MOIST IN THE LOW LEVELS.

&&

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

*LIGHT FREEZING RAIN IS POSSIBLE ACROSS THE INTERIOR NORTHWEST AND
  NORTHERN WORCESTER HILLS*

A WEAK AREA OF LOW PRESSURE DEVELOPS ALONG A WARM FRONT OFF THE MID
ATLANTIC...DRIFTING NORTHWARD TOWARD THE AREA. THIS LOW REMAINS WEAK
AS THE WARM FRONT MOVES SLOWLY NORTHWARD TONIGHT INTO TOMORROW.
DECENT WARM ADVECTION AHEAD OF THIS WAVE WITH SEVERAL HI-RES
GUIDANCE MODELS SHOWS A POTENTIAL FOR COLD AIR DAMMING ACROSS THE
INTERIOR INTO TUESDAY MORNING.  BIGGEST QUESTION WILL BE THE
MOISTURE POTENTIAL...IS THERE ENOUGH TO DEVELOP PRECIP ESP TONIGHT?
GUIDANCE DOES SHOW ENOUGH LIFT AHEAD OF APPROACHING SURFACE LOW PER
THE GFS/EC SO ANTICIPATE PRECIP TO DEVELOP AND OVERSPREAD ACROSS
SOUTHERN NEW ENGLAND. IF THIS PLAYS OUT WITH COLD AIR DAMMING AND
WARM AIR ADVECTION...THEN WE COULD SEE FREEZING RAIN/DRIZZLE ACROSS
THE INTERIOR NORTHWEST AND NORTHERN WORCESTER HILLS VERY LATE
TONIGHT INTO TUESDAY MORNING. A WINTER WEATHER ADVISORY MAY BE
NEEDED.

AS SURFACE LOW CONTINUES TO MOVE NORTHWARD...AND HIGH PRESSURE OVER
EASTERN CANADA...ANTICIPATE AN INCREASING LLJ. THIS SOUTHEASTERLY
JET WILL CONTINUE TO FEED MOISTURE INTO THE REGION AND WITH
SOUNDINGS SHOW A VERY SATURATED PROFILE COULD SEE NUMEROUS SHOWERS
WITH PERHAPS A FEW HEAVY DOWNPOURS. NOTICED GUIDANCE HAS
INCREASED THE QPF OVER THE PAST FEW DAYS. AS THE WEAK SURFACE LOW
MOVES NORTH OF SOUTHERN NEW ENGLAND...WARM FRONT WILL LIFT
NORTHWARD SO ALL PRECIP BY THE LATE MORNING WILL BE IN THE LIQUID
FORM.

WE COULD ALSO SEE SOME MINOR COASTAL FLOODING CONCERNS ON TUESDAY
WITH DUE EASTERLY FLOW INCREASING TO ABOUT 20 TO 25 MPH.  SEE BELOW
FOR MORE DETAILS.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...

HIGHLIGHTS...

* PERIODS OF RAIN TUE NIGHT INTO XMAS MORNING WILL BE HEAVY AT TIMES
* DRY BY XMAS AFTERNOON BUT WINDY
* TEMPS AROUND 60 FOR SOME LATE WED INTO CHRISTMAS MORNING
* DRY BUT ABOVE NORMAL TEMPS CONTINUE FRI AND SAT
* UNSETTLED WEATHER MAY RETURN BY SUN BUT LOW CONFIDENCE

DETAILS...

TUESDAY NIGHT INTO CHRISTMAS...

STRONG SHORTWAVE WILL DIG ACROSS THE CENTRAL U.S. AND ALLOW DEEP
SOUTH TO SOUTHWEST FLOW ALOFT ACROSS SOUTHERN NEW ENGLAND.  THIS
WILL SEND AND ANOMALOUS MILD AIRMASS INTO SOUTHERN NEW ENGLAND FOR
LATE DECEMBER.  GEFS SHOWING PWATS 4 TO 5 STANDARD DEVIATIONS ABOVE
NORMAL BY WED NIGHT ACROSS OUR REGION.  WHILE HEAVY RAIN IS STILL
EXPECTED...THE MODELS HAVE CUT DOWN ON THE QPF IN THE LAST FEW RUNS.
THE MAIN LOW STILL PASSES WELL TO OUR WEST ACROSS GREAT LAKES...BUT
THEIR SLOWER AND WEAKER WITH SECONDARY DEVELOPMENT ACROSS OUR
REGION.  THIS RESULTS IN A WEAKER LOW LEVEL JET...HENCE LESS QPF.
GIVEN ANOMALOUS PWATS IN PLACE...DO NOT WANT TO COMPLETELY LET OUR
GUARD DOWN WITH THE POTENTIAL FOR FLOODING...BUT DOES APPEAR
SOMEWHAT LESS OF A RISK THAN YESTERDAY.  NONETHELESS...STILL EXPECT
TYPICAL NUISANCE POOR DRAINAGE STREET FLOODING.

AS FOR TIMING...SOUTHERLY FLOW ALOFT WILL RESULT IN SCATTERED
SHOWERS TUE NIGHT.  BULK OF THE RAIN WILL OCCUR WED INTO EARLY
CHRISTMAS DAY WHEN STRONGEST FORCING COINCIDES HIGH PWAT AIRMASS.
SOME OF THIS RAIN WILL BE HEAVY AT TIMES MAY RESULT IN NUISANCE POOR
DRAINAGE STREET FLOODING.  STILL A LOW RISK FOR MORE SIGNIFICANT
FLOODING GIVEN EXTREMELY HIGH PWATS...BUT SLOWER DEVELOPMENT OF
SECONDARY LOW PRESSURE MAY BE A LIMITING FACTOR.  REGARDLESS...
EXPECT 1 TO 3 INCHES OF RAIN.  WILL CONTINUE TO MENTION A SLIGHT
CHANCE OF THUNDER WITH SHOWALTER INDICES NEAR ZERO.

THE BULK OF THE RAIN SHOULD COME TO AN END CHRISTMAS MORNING WITH
TEMPS PROBABLY AROUND 60 FOR MUCH OF THE REGION.  WHILE GUSTY
SOUTHERLY WINDS ARE EXPECTED WED NIGHT...INVERSION AND WEAKER LOW
LEVEL JET WILL PROBABLY KEEP MOST AREAS BELOW ADVISORY CRITERIA.
STILL HAVE TO WATCH FOR A SMALL WINDOW ON THE COASTAL PLAIN ESP IF
TEMPS CAN EXCEED 60...BUT HIGHER CONFIDENCE IN WIND ON CHRISTMAS
AFTERNOON AND EVENING BEHIND THE SYSTEM.  INCREASING WESTERLY WIND
ALOFT AND STEEPENING LAPSE RATES WILL BRING THE POTENTIAL FOR THESE
WINDS.  DECENT SHOT AT A PERIOD OF 35 TO 50 MPH GUSTS BEHIND THIS
SYSTEM CHRISTMAS AFTERNOON AND EVENING.  WHILE THE GFS IS AN
OUTLIER...IT WOULD EVEN SUGGEST THE POTENTIAL FOR HIGH WIND CRITERIA
TO BE MET WITH 70 KNOTS AT 850 MB.  THAT MAY BE OVERDONE...BUT
SOMETHING WILL HAVE TO KEEP AN EYE ON THE NEXT FEW DAYS.

FRIDAY AND SATURDAY...

UPPER LEVEL RIDGE OFF THE SOUTHEAST COAST WILL KEEP KEEP US IN MILD
SOUTHWEST FLOW ALOFT.  DRY WEATHER EXPECTED WITH FORCING FOR ANY
PRECIPITATION WILL TO OUR NORTHWEST.  HIGHS MAINLY IN THE 40S TO
LOWER 50S.

SUNDAY...

CONFIDENCE IN THE FORECAST GOES DOWN CONSIDERABLE OVER THIS TIME.
DEVELOPING UPPER LEVEL RIDGING INTO ALASKA WILL SEND THE POLAR JET
SOUTHWARD INTO THE CENTRAL U.S.  AT THE SAME TIME...UPPER LEVEL
RIDGE OFF THE SOUTHEAST COAST WILL TRY TO HANG TOUGH.  THE GFS
INSISTS ON DRY AND COLDER WEATHER ARRIVING...BUT WERE NOT CONVINCED.
GIVEN THE SOUTHEAST RIDGE IT MAY HOLD THE COLD AIR UP AND ALLOW
DEVELOPING LOW PRESSURE TO TRACK NEAR NEW ENGLAND SUN AND SUN NIGHT.
THIS COULD BRING RAIN OR SNOW DEPENDING ON ITS TRACK...OBVIOUSLY A
WEEK OUT SO PLENTY OF UNCERTAINTY BUT WOULD LEAN TOWARDS ANOTHER
SYSTEM AND AWAY FROM THE DRY GFS.

&&

.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 /THROUGH TUESDAY/...

TODAY...HIGH CONFIDENCE. DRIZZLE OR A FEW FLURRIES POSSIBLE
ACROSS EAST MASS TERMINALS. OTHERWISE ANY VFR CIGS WILL DROP TO
MVFR CONDITIONS THROUGHOUT THE DAY.

TONIGHT...MODERATE CONFIDENCE. MAINLY MVFR CONDITIONS CONTINUE IN
SCATTERED LIGHT SNOW SHOWERS. LIGHT FZRA POSSIBLE LATE MONDAY NIGHT
ACROSS NW MASSACHUSETTS.

TUESDAY...MODERATE CONFIDENCE. MVFR CONDITIONS MAY DROP TO IFR
WITHIN AND HEAVY RAIN FALL. VSBYS WILL BE REDUCED TO 5SM OR LESS
AS WELL.

KBOS TERMINAL...MODERATE CONFIDENCE. COULD SEE DRIZZLE LATER TODAY.

KBDL TERMINAL...MODERATE CONFIDENCE.

OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY...

TUESDAY NIGHT INTO THURSDAY MORNING...MODERATE CONFIDENCE.
WIDESPREAD LOW END MVFR TO IFR CONDITIONS EXPECTED IN PERIODS OF
HEAVY SHOWERS/LOW CLOUDS AND FOG PATCHES.  A PERIOD OF SOUTHERLY
WIND GUSTS OF 30 TO 40 KNOTS EXPECTED ON THE COASTAL PLAIN WED
NIGHT.  LLWS ALSO A CONCERN FOR THE ENTIRE REGION WED INTO EARLY THU.

THURSDAY AFTERNOON INTO FRIDAY...MODERATE TO HIGH CONFIDENCE IN
MAINLY VFR.  HOWEVER...A PERIOD OF WESTERLY 30 TO 45 KNOT WIND GUSTS
POSSIBLE THU AFTERNOON AND EVENING.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /THROUGH TUESDAY/...MODERATE TO HIGH CONFIDENCE.

HIGH PRESSURE ACROSS QUEBEC AND THE MARITIMES WILL RESULT IN
PERSISTENT NORTHEASTERLY TO EASTERLY WINDS ACROSS THE WATERS THROUGH
TODAY. THIS WILL BUILD SEAS TO 5FT ON THE EASTERN WATERS DESPITE
WIND GUSTS UP TO 20 KNOTS. HAVE CONTINUED SCA.

APPROACHING SURFACE LOW PRESSURE FROM THE MID-ATLANTIC TONIGHT WILL
HELP INCREASE AN EASTERLY LLJ OVER THE WATER TOMORROW. THIS WILL
BUILD THE SEAS BETWEEN 5-8 FT. COULD SEE WIND GUSTS BETWEEN 20-30
KTS AS THE FRONT PASSES. SCA HAS BEEN EXPANDED ACCORDINGLY.

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

TUESDAY NIGHT...LONG FETCH EASTERLY FLOW WILL CONTINUE TO RESULT IN
SCA SEAS ACROSS THE OUTER-WATERS WITH HIGH PRESSURE MOVING EAST OF
THE CANADIAN MARITIMES.  WINDS SHOULD GENERALLY BE BELOW SMALL CRAFT
THRESHOLDS.

WEDNESDAY INTO EARLY THURSDAY...INTENSIFYING LOW PRESSURE PASSING
WELL TO OUR WEST WILL CAUSE WINDS TO TURN SOUTHERLY AND BECOME
GUSTY. SMALL CRAFT WIND GUSTS ARE A LOCK.  THE MAIN UNCERTAINTY IS
DO WE SEE SOUTHERLY GALES DEVELOP WED NIGHT.  STRONG LOW LEVEL JET
PRESENT...BUT WE WILL BE DEALING WITH AN INVERSION OVER THE
RELATIVELY COOL OCEAN.  REGARDLESS...STILL SHOULD SEE AT LEAST A
PERIOD OF NEAR GALE FORCE SOUTHERLY WIND GUSTS.

LATER THURSDAY INTO FRIDAY...A PERIOD OF WESTERLY GALE FORCE WIND
GUSTS APPEARS LIKELY IN THE COLD ADVECTION PATTERN BEHIND THE STORM
THU AFTERNOON AND NIGHT.  WINDS SHOULD DIMINISH SOME ON FRIDAY.

&&

.TIDES/COASTAL FLOODING...


HIGH ASTRONOMICAL TIDES OCCUR TUE AND WED.

EAST MASSACHUSETTS COAST:

TUESDAY...HIGH TIDE AT BOSTON WILL BE 11.6 FT AT MIDDAY. WINDS WILL
BE FROM THE EAST AT 10 TO 15 KNOTS...SO THERE WILL BE ONSHORE FLOW
DURING THIS HIGH TIDE.  WHILE THIS IS NOTHING TOO STRONG...GIVEN THE
HIGH ASTRO TIDE EXPECT SOME SPLASH OVER/MINOR COASTAL FLOODING.
CERTAINLY DO NOT EXPECT TO SEE ANY SIGNIFICANT ISSUES.

WEDNESDAY...HIGH TIDE AT BOSTON WILL BE 11.7 FT AT MIDDAY.  WINDS
WILL BE FROM THE SOUTHEAST NEAR 10 KNOTS BUT THERE WILL BE SOME
PRESSURE FALLS WITH INTENSIFYING LOW PRESSURE TO OUR WEST.  THIS
SHOULD BE ENOUGH FOR MORE SPLASH OVER/MINOR COASTAL FLOODING WITH
THE HIGH ASTRO TIDES.  HOWEVER...DO NOT EXPECT ANY SIGNIFICANT
PROBLEMS GIVEN WINDS/SEAS SHOULD BE HELD IN CHECK DURING THE TIME OF
HIGH TIDE.

SOUTH COAST:

WEDNESDAY EVENING...SOUTHERLY WINDS ARE EXPECTED AND ASTRONOMICAL
TIDES INCREASE ALONG THE SOUTH COAST. HIGH TIDE IN PROVIDENCE WILL
BE 5.2 FT THAT EVENING. 925 MB LLJ STRENGTHENS TO 55-65 KTS WHICH
COULD PUSH A 1 TO 2 FOOT SURGE UP ALONG THE SOUTH COAST DURING THE
TIME OF HIGH TIDE.  THE LOW LEVEL INVERSION WILL PROBABLY HOLD THE
STRONGEST WINDS JUST ABOVE THE GROUND...SO THINKING THE RISK IS FOR
SPLASH OVER AND MINOR COASTAL FLOODING.  THERE STILL IS A LOW RISK
FOR MODERATE COASTAL FLOODING...BUT THAT IS OFTEN HARD TO GET IN A
NON-TROPICAL SYSTEM ALONG THE SOUTH COAST.


&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 1 AM TO 7 PM EST TUESDAY FOR ANZ231-
     232-251-256.
     SMALL CRAFT ADVISORY FROM 1 PM THIS AFTERNOON TO 7 PM EST
     TUESDAY FOR ANZ250-254.
     SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 7 PM EST
     TUESDAY FOR ANZ255.

&&

$$
SYNOPSIS...FRANK/DUNTEN
NEAR TERM...DUNTEN
SHORT TERM...DUNTEN
LONG TERM...FRANK
AVIATION...FRANK/DUNTEN
MARINE...FRANK/DUNTEN
TIDES/COASTAL FLOODING...FRANK




000
FXUS61 KBOX 220927
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
416 AM EST MON DEC 22 2014

.SYNOPSIS...

A WAVE OF LOW PRESSURE WILL BRING THE PERIODS OF WET WEATHER MAINLY
LATE TONIGHT INTO TUESDAY NIGHT...WHICH MAY BEGIN AS A BRIEF PERIOD
OF FROZEN PRECIPITATION ACROSS NORTHWEST MASSACHUSETTS.  A MUCH
STRONGER STORM PASSING WELL TO OUR WEST WEDNESDAY INTO CHRISTMAS
MORNING WILL BRING HEAVY RAIN...GUSTY WINDS AND MINOR COASTAL
FLOODING.  DRY WEATHER WITH ABOVE NORMAL TEMPERATURES EXPECTED
CHRISTMAS AFTERNOON INTO SATURDAY.  LOW PRESSURE MAY BRING A RETURN
TO UNSETTLED WEATHER BY NEXT SUNDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPPER LEVEL RIDGE BUILDS AHEAD OF DIGGING MIDWEST TROUGH WITH
HIGH PRESSURE REMAINING ANCHORED OVER THE CANADIAN MARITIMES
THROUGH TONIGHT.

EASTERLY FLOW WILL CONTINUE ONSHORE ALLOWING FOR THE PROFILE TO
CONTINUE TO MOISTEN IN THE LOW LEVELS. IF THIS MOISTURE DEEPENS
ENOUGH THEN WE COULD SEE LIGHT SHOWERS DEVELOP ESP ACROSS THE MASS
EAST COASTLINE. OTHERWISE DRIZZLE MAY BE THE MAIN FACTOR AS THE
UPPER LEVELS ARE FAIRLY DRY. OVERALL TODAY WILL BE A COOL AND CLOUDY
DAY WITH HIGHS ONLY REACHING IN THE UPPER 30S TO LOW 40S AS CROSS
SECTIONS ARE VERY MOIST IN THE LOW LEVELS.

&&

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

*LIGHT FREEZING RAIN IS POSSIBLE ACROSS THE INTERIOR NORTHWEST AND
  NORTHERN WORCESTER HILLS*

A WEAK AREA OF LOW PRESSURE DEVELOPS ALONG A WARM FRONT OFF THE MID
ATLANTIC...DRIFTING NORTHWARD TOWARD THE AREA. THIS LOW REMAINS WEAK
AS THE WARM FRONT MOVES SLOWLY NORTHWARD TONIGHT INTO TOMORROW.
DECENT WARM ADVECTION AHEAD OF THIS WAVE WITH SEVERAL HI-RES
GUIDANCE MODELS SHOWS A POTENTIAL FOR COLD AIR DAMMING ACROSS THE
INTERIOR INTO TUESDAY MORNING.  BIGGEST QUESTION WILL BE THE
MOISTURE POTENTIAL...IS THERE ENOUGH TO DEVELOP PRECIP ESP TONIGHT?
GUIDANCE DOES SHOW ENOUGH LIFT AHEAD OF APPROACHING SURFACE LOW PER
THE GFS/EC SO ANTICIPATE PRECIP TO DEVELOP AND OVERSPREAD ACROSS
SOUTHERN NEW ENGLAND. IF THIS PLAYS OUT WITH COLD AIR DAMMING AND
WARM AIR ADVECTION...THEN WE COULD SEE FREEZING RAIN/DRIZZLE ACROSS
THE INTERIOR NORTHWEST AND NORTHERN WORCESTER HILLS VERY LATE
TONIGHT INTO TUESDAY MORNING. A WINTER WEATHER ADVISORY MAY BE
NEEDED.

AS SURFACE LOW CONTINUES TO MOVE NORTHWARD...AND HIGH PRESSURE OVER
EASTERN CANADA...ANTICIPATE AN INCREASING LLJ. THIS SOUTHEASTERLY
JET WILL CONTINUE TO FEED MOISTURE INTO THE REGION AND WITH
SOUNDINGS SHOW A VERY SATURATED PROFILE COULD SEE NUMEROUS SHOWERS
WITH PERHAPS A FEW HEAVY DOWNPOURS. NOTICED GUIDANCE HAS
INCREASED THE QPF OVER THE PAST FEW DAYS. AS THE WEAK SURFACE LOW
MOVES NORTH OF SOUTHERN NEW ENGLAND...WARM FRONT WILL LIFT
NORTHWARD SO ALL PRECIP BY THE LATE MORNING WILL BE IN THE LIQUID
FORM.

WE COULD ALSO SEE SOME MINOR COASTAL FLOODING CONCERNS ON TUESDAY
WITH DUE EASTERLY FLOW INCREASING TO ABOUT 20 TO 25 MPH.  SEE BELOW
FOR MORE DETAILS.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...

HIGHLIGHTS...

* PERIODS OF RAIN TUE NIGHT INTO XMAS MORNING WILL BE HEAVY AT TIMES
* DRY BY XMAS AFTERNOON BUT WINDY
* TEMPS AROUND 60 FOR SOME LATE WED INTO CHRISTMAS MORNING
* DRY BUT ABOVE NORMAL TEMPS CONTINUE FRI AND SAT
* UNSETTLED WEATHER MAY RETURN BY SUN BUT LOW CONFIDENCE

DETAILS...

TUESDAY NIGHT INTO CHRISTMAS...

STRONG SHORTWAVE WILL DIG ACROSS THE CENTRAL U.S. AND ALLOW DEEP
SOUTH TO SOUTHWEST FLOW ALOFT ACROSS SOUTHERN NEW ENGLAND.  THIS
WILL SEND AND ANOMALOUS MILD AIRMASS INTO SOUTHERN NEW ENGLAND FOR
LATE DECEMBER.  GEFS SHOWING PWATS 4 TO 5 STANDARD DEVIATIONS ABOVE
NORMAL BY WED NIGHT ACROSS OUR REGION.  WHILE HEAVY RAIN IS STILL
EXPECTED...THE MODELS HAVE CUT DOWN ON THE QPF IN THE LAST FEW RUNS.
THE MAIN LOW STILL PASSES WELL TO OUR WEST ACROSS GREAT LAKES...BUT
THEIR SLOWER AND WEAKER WITH SECONDARY DEVELOPMENT ACROSS OUR
REGION.  THIS RESULTS IN A WEAKER LOW LEVEL JET...HENCE LESS QPF.
GIVEN ANOMALOUS PWATS IN PLACE...DO NOT WANT TO COMPLETELY LET OUR
GUARD DOWN WITH THE POTENTIAL FOR FLOODING...BUT DOES APPEAR
SOMEWHAT LESS OF A RISK THAN YESTERDAY.  NONETHELESS...STILL EXPECT
TYPICAL NUISANCE POOR DRAINAGE STREET FLOODING.

AS FOR TIMING...SOUTHERLY FLOW ALOFT WILL RESULT IN SCATTERED
SHOWERS TUE NIGHT.  BULK OF THE RAIN WILL OCCUR WED INTO EARLY
CHRISTMAS DAY WHEN STRONGEST FORCING COINCIDES HIGH PWAT AIRMASS.
SOME OF THIS RAIN WILL BE HEAVY AT TIMES MAY RESULT IN NUISANCE POOR
DRAINAGE STREET FLOODING.  STILL A LOW RISK FOR MORE SIGNIFICANT
FLOODING GIVEN EXTREMELY HIGH PWATS...BUT SLOWER DEVELOPMENT OF
SECONDARY LOW PRESSURE MAY BE A LIMITING FACTOR.  REGARDLESS...
EXPECT 1 TO 3 INCHES OF RAIN.  WILL CONTINUE TO MENTION A SLIGHT
CHANCE OF THUNDER WITH SHOWALTER INDICES NEAR ZERO.

THE BULK OF THE RAIN SHOULD COME TO AN END CHRISTMAS MORNING WITH
TEMPS PROBABLY AROUND 60 FOR MUCH OF THE REGION.  WHILE GUSTY
SOUTHERLY WINDS ARE EXPECTED WED NIGHT...INVERSION AND WEAKER LOW
LEVEL JET WILL PROBABLY KEEP MOST AREAS BELOW ADVISORY CRITERIA.
STILL HAVE TO WATCH FOR A SMALL WINDOW ON THE COASTAL PLAIN ESP IF
TEMPS CAN EXCEED 60...BUT HIGHER CONFIDENCE IN WIND ON CHRISTMAS
AFTERNOON AND EVENING BEHIND THE SYSTEM.  INCREASING WESTERLY WIND
ALOFT AND STEEPENING LAPSE RATES WILL BRING THE POTENTIAL FOR THESE
WINDS.  DECENT SHOT AT A PERIOD OF 35 TO 50 MPH GUSTS BEHIND THIS
SYSTEM CHRISTMAS AFTERNOON AND EVENING.  WHILE THE GFS IS AN
OUTLIER...IT WOULD EVEN SUGGEST THE POTENTIAL FOR HIGH WIND CRITERIA
TO BE MET WITH 70 KNOTS AT 850 MB.  THAT MAY BE OVERDONE...BUT
SOMETHING WILL HAVE TO KEEP AN EYE ON THE NEXT FEW DAYS.

FRIDAY AND SATURDAY...

UPPER LEVEL RIDGE OFF THE SOUTHEAST COAST WILL KEEP KEEP US IN MILD
SOUTHWEST FLOW ALOFT.  DRY WEATHER EXPECTED WITH FORCING FOR ANY
PRECIPITATION WILL TO OUR NORTHWEST.  HIGHS MAINLY IN THE 40S TO
LOWER 50S.

SUNDAY...

CONFIDENCE IN THE FORECAST GOES DOWN CONSIDERABLE OVER THIS TIME.
DEVELOPING UPPER LEVEL RIDGING INTO ALASKA WILL SEND THE POLAR JET
SOUTHWARD INTO THE CENTRAL U.S.  AT THE SAME TIME...UPPER LEVEL
RIDGE OFF THE SOUTHEAST COAST WILL TRY TO HANG TOUGH.  THE GFS
INSISTS ON DRY AND COLDER WEATHER ARRIVING...BUT WERE NOT CONVINCED.
GIVEN THE SOUTHEAST RIDGE IT MAY HOLD THE COLD AIR UP AND ALLOW
DEVELOPING LOW PRESSURE TO TRACK NEAR NEW ENGLAND SUN AND SUN NIGHT.
THIS COULD BRING RAIN OR SNOW DEPENDING ON ITS TRACK...OBVIOUSLY A
WEEK OUT SO PLENTY OF UNCERTAINTY BUT WOULD LEAN TOWARDS ANOTHER
SYSTEM AND AWAY FROM THE DRY GFS.

&&

.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 /THROUGH TUESDAY/...

TODAY...HIGH CONFIDENCE. DRIZZLE OR A FEW FLURRIES POSSIBLE
ACROSS EAST MASS TERMINALS. OTHERWISE ANY VFR CIGS WILL DROP TO
MVFR CONDITIONS THROUGHOUT THE DAY.

TONIGHT...MODERATE CONFIDENCE. MAINLY MVFR CONDITIONS CONTINUE IN
SCATTERED LIGHT SNOW SHOWERS. LIGHT FZRA POSSIBLE LATE MONDAY NIGHT
ACROSS NW MASSACHUSETTS.

TUESDAY...MODERATE CONFIDENCE. MVFR CONDITIONS MAY DROP TO IFR
WITHIN AND HEAVY RAIN FALL. VSBYS WILL BE REDUCED TO 5SM OR LESS
AS WELL.

KBOS TERMINAL...MODERATE CONFIDENCE. COULD SEE DRIZZLE LATER TODAY.

KBDL TERMINAL...MODERATE CONFIDENCE.

OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY...

TUESDAY NIGHT INTO THURSDAY MORNING...MODERATE CONFIDENCE.
WIDESPREAD LOW END MVFR TO IFR CONDITIONS EXPECTED IN PERIODS OF
HEAVY SHOWERS/LOW CLOUDS AND FOG PATCHES.  A PERIOD OF SOUTHERLY
WIND GUSTS OF 30 TO 40 KNOTS EXPECTED ON THE COASTAL PLAIN WED
NIGHT.  LLWS ALSO A CONCERN FOR THE ENTIRE REGION WED INTO EARLY THU.

THURSDAY AFTERNOON INTO FRIDAY...MODERATE TO HIGH CONFIDENCE IN
MAINLY VFR.  HOWEVER...A PERIOD OF WESTERLY 30 TO 45 KNOT WIND GUSTS
POSSIBLE THU AFTERNOON AND EVENING.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /THROUGH TUESDAY/...MODERATE TO HIGH CONFIDENCE.

HIGH PRESSURE ACROSS QUEBEC AND THE MARITIMES WILL RESULT IN
PERSISTENT NORTHEASTERLY TO EASTERLY WINDS ACROSS THE WATERS THROUGH
TODAY. THIS WILL BUILD SEAS TO 5FT ON THE EASTERN WATERS DESPITE
WIND GUSTS UP TO 20 KNOTS. HAVE CONTINUED SCA.

APPROACHING SURFACE LOW PRESSURE FROM THE MID-ATLANTIC TONIGHT WILL
HELP INCREASE AN EASTERLY LLJ OVER THE WATER TOMORROW. THIS WILL
BUILD THE SEAS BETWEEN 5-8 FT. COULD SEE WIND GUSTS BETWEEN 20-30
KTS AS THE FRONT PASSES. SCA HAS BEEN EXPANDED ACCORDINGLY.

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

TUESDAY NIGHT...LONG FETCH EASTERLY FLOW WILL CONTINUE TO RESULT IN
SCA SEAS ACROSS THE OUTER-WATERS WITH HIGH PRESSURE MOVING EAST OF
THE CANADIAN MARITIMES.  WINDS SHOULD GENERALLY BE BELOW SMALL CRAFT
THRESHOLDS.

WEDNESDAY INTO EARLY THURSDAY...INTENSIFYING LOW PRESSURE PASSING
WELL TO OUR WEST WILL CAUSE WINDS TO TURN SOUTHERLY AND BECOME
GUSTY. SMALL CRAFT WIND GUSTS ARE A LOCK.  THE MAIN UNCERTAINTY IS
DO WE SEE SOUTHERLY GALES DEVELOP WED NIGHT.  STRONG LOW LEVEL JET
PRESENT...BUT WE WILL BE DEALING WITH AN INVERSION OVER THE
RELATIVELY COOL OCEAN.  REGARDLESS...STILL SHOULD SEE AT LEAST A
PERIOD OF NEAR GALE FORCE SOUTHERLY WIND GUSTS.

LATER THURSDAY INTO FRIDAY...A PERIOD OF WESTERLY GALE FORCE WIND
GUSTS APPEARS LIKELY IN THE COLD ADVECTION PATTERN BEHIND THE STORM
THU AFTERNOON AND NIGHT.  WINDS SHOULD DIMINISH SOME ON FRIDAY.

&&

.TIDES/COASTAL FLOODING...


HIGH ASTRONOMICAL TIDES OCCUR TUE AND WED.

EAST MASSACHUSETTS COAST:

TUESDAY...HIGH TIDE AT BOSTON WILL BE 11.6 FT AT MIDDAY. WINDS WILL
BE FROM THE EAST AT 10 TO 15 KNOTS...SO THERE WILL BE ONSHORE FLOW
DURING THIS HIGH TIDE.  WHILE THIS IS NOTHING TOO STRONG...GIVEN THE
HIGH ASTRO TIDE EXPECT SOME SPLASH OVER/MINOR COASTAL FLOODING.
CERTAINLY DO NOT EXPECT TO SEE ANY SIGNIFICANT ISSUES.

WEDNESDAY...HIGH TIDE AT BOSTON WILL BE 11.7 FT AT MIDDAY.  WINDS
WILL BE FROM THE SOUTHEAST NEAR 10 KNOTS BUT THERE WILL BE SOME
PRESSURE FALLS WITH INTENSIFYING LOW PRESSURE TO OUR WEST.  THIS
SHOULD BE ENOUGH FOR MORE SPLASH OVER/MINOR COASTAL FLOODING WITH
THE HIGH ASTRO TIDES.  HOWEVER...DO NOT EXPECT ANY SIGNIFICANT
PROBLEMS GIVEN WINDS/SEAS SHOULD BE HELD IN CHECK DURING THE TIME OF
HIGH TIDE.

SOUTH COAST:

WEDNESDAY EVENING...SOUTHERLY WINDS ARE EXPECTED AND ASTRONOMICAL
TIDES INCREASE ALONG THE SOUTH COAST. HIGH TIDE IN PROVIDENCE WILL
BE 5.2 FT THAT EVENING. 925 MB LLJ STRENGTHENS TO 55-65 KTS WHICH
COULD PUSH A 1 TO 2 FOOT SURGE UP ALONG THE SOUTH COAST DURING THE
TIME OF HIGH TIDE.  THE LOW LEVEL INVERSION WILL PROBABLY HOLD THE
STRONGEST WINDS JUST ABOVE THE GROUND...SO THINKING THE RISK IS FOR
SPLASH OVER AND MINOR COASTAL FLOODING.  THERE STILL IS A LOW RISK
FOR MODERATE COASTAL FLOODING...BUT THAT IS OFTEN HARD TO GET IN A
NON-TROPICAL SYSTEM ALONG THE SOUTH COAST.


&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 1 AM TO 7 PM EST TUESDAY FOR ANZ231-
     232-251-256.
     SMALL CRAFT ADVISORY FROM 1 PM THIS AFTERNOON TO 7 PM EST
     TUESDAY FOR ANZ250-254.
     SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 7 PM EST
     TUESDAY FOR ANZ255.

&&

$$
SYNOPSIS...FRANK/DUNTEN
NEAR TERM...DUNTEN
SHORT TERM...DUNTEN
LONG TERM...FRANK
AVIATION...FRANK/DUNTEN
MARINE...FRANK/DUNTEN
TIDES/COASTAL FLOODING...FRANK





000
FXUS61 KBOX 220916
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
416 AM EST MON DEC 22 2014

.SYNOPSIS...

A WAVE OF LOW PRESSURE WILL BRING THE PERIODS OF WET WEATHER MAINLY
LATE TONIGHT INTO TUESDAY NIGHT...WHICH MAY BEGIN AS A BRIEF PERIOD
OF FROZEN PRECIPITATION ACROSS NORTHWEST MASSACHUSETTS.  A MUCH
STRONGER STORM PASSING WELL TO OUR WEST WEDNESDAY INTO CHRISTMAS
MORNING WILL BRING HEAVY RAIN...GUSTY WINDS AND MINOR COASTAL
FLOODING.  DRY WEATHER WITH ABOVE NORMAL TEMPERATURES EXPECTED
CHRISTMAS AFTERNOON INTO SATURDAY.  LOW PRESSURE MAY BRING A RETURN
TO UNSETTLED WEATHER BY WEDNESDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPPER LEVEL RIDGE BUILDS AHEAD OF DIGGING MIDWEST TROUGH WITH
HIGH PRESSURE REMAINING ANCHORED OVER THE CANADIAN MARITIMES
THROUGH TONIGHT.

EASTERLY FLOW WILL CONTINUE ONSHORE ALLOWING FOR THE PROFILE TO
CONTINUE TO MOISTEN IN THE LOW LEVELS. IF THIS MOISTURE DEEPENS
ENOUGH THEN WE COULD SEE LIGHT SHOWERS DEVELOP ESP ACROSS THE MASS
EAST COASTLINE. OTHERWISE DRIZZLE MAY BE THE MAIN FACTOR AS THE
UPPER LEVELS ARE FAIRLY DRY. OVERALL TODAY WILL BE A COOL AND CLOUDY
DAY WITH HIGHS ONLY REACHING IN THE UPPER 30S TO LOW 40S AS CROSS
SECTIONS ARE VERY MOIST IN THE LOW LEVELS.

&&

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

*LIGHT FREEZING RAIN IS POSSIBLE ACROSS THE INTERIOR NORTHWEST AND
  NORTHERN WORCESTER HILLS*

A WEAK AREA OF LOW PRESSURE DEVELOPS ALONG A WARM FRONT OFF THE MID
ATLANTIC...DRIFTING NORTHWARD TOWARD THE AREA. THIS LOW REMAINS WEAK
AS THE WARM FRONT MOVES SLOWLY NORTHWARD TONIGHT INTO TOMORROW.
DECENT WARM ADVECTION AHEAD OF THIS WAVE WITH SEVERAL HI-RES
GUIDANCE MODELS SHOWS A POTENTIAL FOR COLD AIR DAMMING ACROSS THE
INTERIOR INTO TUESDAY MORNING.  BIGGEST QUESTION WILL BE THE
MOISTURE POTENTIAL...IS THERE ENOUGH TO DEVELOP PRECIP ESP TONIGHT?
GUIDANCE DOES SHOW ENOUGH LIFT AHEAD OF APPROACHING SURFACE LOW PER
THE GFS/EC SO ANTICIPATE PRECIP TO DEVELOP AND OVERSPREAD ACROSS
SOUTHERN NEW ENGLAND. IF THIS PLAYS OUT WITH COLD AIR DAMMING AND
WARM AIR ADVECTION...THEN WE COULD SEE FREEZING RAIN/DRIZZLE ACROSS
THE INTERIOR NORTHWEST AND NORTHERN WORCESTER HILLS VERY LATE
TONIGHT INTO TUESDAY MORNING. A WINTER WEATHER ADVISORY MAY BE
NEEDED.

AS SURFACE LOW CONTINUES TO MOVE NORTHWARD...AND HIGH PRESSURE OVER
EASTERN CANADA...ANTICIPATE AN INCREASING LLJ. THIS SOUTHEASTERLY
JET WILL CONTINUE TO FEED MOISTURE INTO THE REGION AND WITH
SOUNDINGS SHOW A VERY SATURATED PROFILE COULD SEE NUMEROUS SHOWERS
WITH PERHAPS A FEW HEAVY DOWNPOURS. NOTICED GUIDANCE HAS
INCREASED THE QPF OVER THE PAST FEW DAYS. AS THE WEAK SURFACE LOW
MOVES NORTH OF SOUTHERN NEW ENGLAND...WARM FRONT WILL LIFT
NORTHWARD SO ALL PRECIP BY THE LATE MORNING WILL BE IN THE LIQUID
FORM.

WE COULD ALSO SEE SOME MINOR COASTAL FLOODING CONCERNS ON TUESDAY
WITH DUE EASTERLY FLOW INCREASING TO ABOUT 20 TO 25 MPH.  SEE BELOW
FOR MORE DETAILS.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...

HIGHLIGHTS...

* PERIODS OF RAIN TUE NIGHT INTO XMAS MORNING WILL BE HEAVY AT TIMES
* DRY BY XMAS AFTERNOON BUT WINDY
* TEMPS AROUND 60 FOR SOME LATE WED INTO CHRISTMAS MORNING
* DRY BUT ABOVE NORMAL TEMPS CONTINUE FRI AND SAT
* UNSETTLED WEATHER MAY RETURN BY SUN BUT LOW CONFIDENCE

DETAILS...

TUESDAY NIGHT INTO CHRISTMAS...

STRONG SHORTWAVE WILL DIG ACROSS THE CENTRAL U.S. AND ALLOW DEEP
SOUTH TO SOUTHWEST FLOW ALOFT ACROSS SOUTHERN NEW ENGLAND.  THIS
WILL SEND AND ANOMALOUS MILD AIRMASS INTO SOUTHERN NEW ENGLAND FOR
LATE DECEMBER.  GEFS SHOWING PWATS 4 TO 5 STANDARD DEVIATIONS ABOVE
NORMAL BY WED NIGHT ACROSS OUR REGION.  WHILE HEAVY RAIN IS STILL
EXPECTED...THE MODELS HAVE CUT DOWN ON THE QPF IN THE LAST FEW RUNS.
THE MAIN LOW STILL PASSES WELL TO OUR WEST ACROSS GREAT LAKES...BUT
THEIR SLOWER AND WEAKER WITH SECONDARY DEVELOPMENT ACROSS OUR
REGION.  THIS RESULTS IN A WEAKER LOW LEVEL JET...HENCE LESS QPF.
GIVEN ANOMALOUS PWATS IN PLACE...DO NOT WANT TO COMPLETELY LET OUR
GUARD DOWN WITH THE POTENTIAL FOR FLOODING...BUT DOES APPEAR
SOMEWHAT LESS OF A RISK THAN YESTERDAY.  NONETHELESS...STILL EXPECT
TYPICAL NUISANCE POOR DRAINAGE STREET FLOODING.

AS FOR TIMING...SOUTHERLY FLOW ALOFT WILL RESULT IN SCATTERED
SHOWERS TUE NIGHT.  BULK OF THE RAIN WILL OCCUR WED INTO EARLY
CHRISTMAS DAY WHEN STRONGEST FORCING COINCIDES HIGH PWAT AIRMASS.
SOME OF THIS RAIN WILL BE HEAVY AT TIMES MAY RESULT IN NUISANCE POOR
DRAINAGE STREET FLOODING.  STILL A LOW RISK FOR MORE SIGNIFICANT
FLOODING GIVEN EXTREMELY HIGH PWATS...BUT SLOWER DEVELOPMENT OF
SECONDARY LOW PRESSURE MAY BE A LIMITING FACTOR.  REGARDLESS...
EXPECT 1 TO 3 INCHES OF RAIN.  WILL CONTINUE TO MENTION A SLIGHT
CHANCE OF THUNDER WITH SHOWALTER INDICES NEAR ZERO.

THE BULK OF THE RAIN SHOULD COME TO AN END CHRISTMAS MORNING WITH
TEMPS PROBABLY AROUND 60 FOR MUCH OF THE REGION.  WHILE GUSTY
SOUTHERLY WINDS ARE EXPECTED WED NIGHT...INVERSION AND WEAKER LOW
LEVEL JET WILL PROBABLY KEEP MOST AREAS BELOW ADVISORY CRITERIA.
STILL HAVE TO WATCH FOR A SMALL WINDOW ON THE COASTAL PLAIN ESP IF
TEMPS CAN EXCEED 60...BUT HIGHER CONFIDENCE IN WIND ON CHRISTMAS
AFTERNOON AND EVENING BEHIND THE SYSTEM.  INCREASING WESTERLY WIND
ALOFT AND STEEPENING LAPSE RATES WILL BRING THE POTENTIAL FOR THESE
WINDS.  DECENT SHOT AT A PERIOD OF 35 TO 50 MPH GUSTS BEHIND THIS
SYSTEM CHRISTMAS AFTERNOON AND EVENING.  WHILE THE GFS IS AN
OUTLIER...IT WOULD EVEN SUGGEST THE POTENTIAL FOR HIGH WIND CRITERIA
TO BE MET WITH 70 KNOTS AT 850 MB.  THAT MAY BE OVERDONE...BUT
SOMETHING WILL HAVE TO KEEP AN EYE ON THE NEXT FEW DAYS.

FRIDAY AND SATURDAY...

UPPER LEVEL RIDGE OFF THE SOUTHEAST COAST WILL KEEP KEEP US IN MILD
SOUTHWEST FLOW ALOFT.  DRY WEATHER EXPECTED WITH FORCING FOR ANY
PRECIPITATION WILL TO OUR NORTHWEST.  HIGHS MAINLY IN THE 40S TO
LOWER 50S.

SUNDAY...

CONFIDENCE IN THE FORECAST GOES DOWN CONSIDERABLE OVER THIS TIME.
DEVELOPING UPPER LEVEL RIDGING INTO ALASKA WILL SEND THE POLAR JET
SOUTHWARD INTO THE CENTRAL U.S.  AT THE SAME TIME...UPPER LEVEL
RIDGE OFF THE SOUTHEAST COAST WILL TRY TO HANG TOUGH.  THE GFS
INSISTS ON DRY AND COLDER WEATHER ARRIVING...BUT WERE NOT CONVINCED.
GIVEN THE SOUTHEAST RIDGE IT MAY HOLD THE COLD AIR UP AND ALLOW
DEVELOPING LOW PRESSURE TO TRACK NEAR NEW ENGLAND SUN AND SUN NIGHT.
THIS COULD BRING RAIN OR SNOW DEPENDING ON ITS TRACK...OBVIOUSLY A
WEEK OUT SO PLENTY OF UNCERTAINTY BUT WOULD LEAN TOWARDS ANOTHER
SYSTEM AND AWAY FROM THE DRY GFS.

&&

.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 /THROUGH TUESDAY/...

TODAY...HIGH CONFIDENCE. DRIZZLE OR A FEW FLURRIES POSSIBLE
ACROSS EAST MASS TERMINALS. OTHERWISE ANY VFR CIGS WILL DROP TO
MVFR CONDITIONS THROUGHOUT THE DAY.

TONIGHT...MODERATE CONFIDENCE. MAINLY MVFR CONDITIONS CONTINUE IN
SCATTERED LIGHT SNOW SHOWERS. LIGHT FZRA POSSIBLE LATE MONDAY NIGHT
ACROSS NW MASSACHUSETTS.

TUESDAY...MODERATE CONFIDENCE. MVFR CONDITIONS MAY DROP TO IFR
WITHIN AND HEAVY RAIN FALL. VSBYS WILL BE REDUCED TO 5SM OR LESS
AS WELL.

KBOS TERMINAL...MODERATE CONFIDENCE. COULD SEE DRIZZLE LATER TODAY.

KBDL TERMINAL...MODERATE CONFIDENCE.

OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY...

TUESDAY NIGHT INTO THURSDAY MORNING...MODERATE CONFIDENCE.
WIDESPREAD LOW END MVFR TO IFR CONDITIONS EXPECTED IN PERIODS OF
HEAVY SHOWERS/LOW CLOUDS AND FOG PATCHES.  A PERIOD OF SOUTHERLY
WIND GUSTS OF 30 TO 40 KNOTS EXPECTED ON THE COASTAL PLAIN WED
NIGHT.  LLWS ALSO A CONCERN FOR THE ENTIRE REGION WED INTO EARLY THU.

THURSDAY AFTERNOON INTO FRIDAY...MODERATE TO HIGH CONFIDENCE IN
MAINLY VFR.  HOWEVER...A PERIOD OF WESTERLY 30 TO 45 KNOT WIND GUSTS
POSSIBLE THU AFTERNOON AND EVENING.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /THROUGH TUESDAY/...MODERATE TO HIGH CONFIDENCE.

HIGH PRESSURE ACROSS QUEBEC AND THE MARITIMES WILL RESULT IN
PERSISTENT NORTHEASTERLY TO EASTERLY WINDS ACROSS THE WATERS THROUGH
TODAY. THIS WILL BUILD SEAS TO 5FT ON THE EASTERN WATERS DESPITE
WIND GUSTS UP TO 20 KNOTS. HAVE CONTINUED SCA.

APPROACHING SURFACE LOW PRESSURE FROM THE MID-ATLANTIC TONIGHT WILL
HELP INCREASE AN EASTERLY LLJ OVER THE WATER TOMORROW. THIS WILL
BUILD THE SEAS BETWEEN 5-8 FT. COULD SEE WIND GUSTS BETWEEN 20-30
KTS AS THE FRONT PASSES. SCA HAS BEEN EXPANDED ACCORDINGLY.

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

TUESDAY NIGHT...LONG FETCH EASTERLY FLOW WILL CONTINUE TO RESULT IN
SCA SEAS ACROSS THE OUTER-WATERS WITH HIGH PRESSURE MOVING EAST OF
THE CANADIAN MARITIMES.  WINDS SHOULD GENERALLY BE BELOW SMALL CRAFT
THRESHOLDS.

WEDNESDAY INTO EARLY THURSDAY...INTENSIFYING LOW PRESSURE PASSING
WELL TO OUR WEST WILL CAUSE WINDS TO TURN SOUTHERLY AND BECOME
GUSTY. SMALL CRAFT WIND GUSTS ARE A LOCK.  THE MAIN UNCERTAINTY IS
DO WE SEE SOUTHERLY GALES DEVELOP WED NIGHT.  STRONG LOW LEVEL JET
PRESENT...BUT WE WILL BE DEALING WITH AN INVERSION OVER THE
RELATIVELY COOL OCEAN.  REGARDLESS...STILL SHOULD SEE AT LEAST A
PERIOD OF NEAR GALE FORCE SOUTHERLY WIND GUSTS.

LATER THURSDAY INTO FRIDAY...A PERIOD OF WESTERLY GALE FORCE WIND
GUSTS APPEARS LIKELY IN THE COLD ADVECTION PATTERN BEHIND THE STORM
THU AFTERNOON AND NIGHT.  WINDS SHOULD DIMINISH SOME ON FRIDAY.

&&

.TIDES/COASTAL FLOODING...


HIGH ASTRONOMICAL TIDES OCCUR TUE AND WED.

EAST MASSACHUSETTS COAST:

TUESDAY...HIGH TIDE AT BOSTON WILL BE 11.6 FT AT MIDDAY. WINDS WILL
BE FROM THE EAST AT 10 TO 15 KNOTS...SO THERE WILL BE ONSHORE FLOW
DURING THIS HIGH TIDE.  WHILE THIS IS NOTHING TOO STRONG...GIVEN THE
HIGH ASTRO TIDE EXPECT SOME SPLASH OVER/MINOR COASTAL FLOODING.
CERTAINLY DO NOT EXPECT TO SEE ANY SIGNIFICANT ISSUES.

WEDNESDAY...HIGH TIDE AT BOSTON WILL BE 11.7 FT AT MIDDAY.  WINDS
WILL BE FROM THE SOUTHEAST NEAR 10 KNOTS BUT THERE WILL BE SOME
PRESSURE FALLS WITH INTENSIFYING LOW PRESSURE TO OUR WEST.  THIS
SHOULD BE ENOUGH FOR MORE SPLASH OVER/MINOR COASTAL FLOODING WITH
THE HIGH ASTRO TIDES.  HOWEVER...DO NOT EXPECT ANY SIGNIFICANT
PROBLEMS GIVEN WINDS/SEAS SHOULD BE HELD IN CHECK DURING THE TIME OF
HIGH TIDE.

SOUTH COAST:

WEDNESDAY EVENING...SOUTHERLY WINDS ARE EXPECTED AND ASTRONOMICAL
TIDES INCREASE ALONG THE SOUTH COAST. HIGH TIDE IN PROVIDENCE WILL
BE 5.2 FT THAT EVENING. 925 MB LLJ STRENGTHENS TO 55-65 KTS WHICH
COULD PUSH A 1 TO 2 FOOT SURGE UP ALONG THE SOUTH COAST DURING THE
TIME OF HIGH TIDE.  THE LOW LEVEL INVERSION WILL PROBABLY HOLD THE
STRONGEST WINDS JUST ABOVE THE GROUND...SO THINKING THE RISK IS FOR
SPLASH OVER AND MINOR COASTAL FLOODING.  THERE STILL IS A LOW RISK
FOR MODERATE COASTAL FLOODING...BUT THAT IS OFTEN HARD TO GET IN A
NON-TROPICAL SYSTEM ALONG THE SOUTH COAST.


&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 1 AM TO 7 PM EST TUESDAY FOR ANZ231-
     232-251-256.
     SMALL CRAFT ADVISORY FROM 1 PM THIS AFTERNOON TO 7 PM EST
     TUESDAY FOR ANZ250-254.
     SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 7 PM EST
     TUESDAY FOR ANZ255.

&&

$$
SYNOPSIS...FRANK/DUNTEN
NEAR TERM...DUNTEN
SHORT TERM...DUNTEN
LONG TERM...FRANK
AVIATION...FRANK/DUNTEN
MARINE...FRANK/DUNTEN
TIDES/COASTAL FLOODING...FRANK





000
FXUS61 KBOX 220916
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
416 AM EST MON DEC 22 2014

.SYNOPSIS...

A WAVE OF LOW PRESSURE WILL BRING THE PERIODS OF WET WEATHER MAINLY
LATE TONIGHT INTO TUESDAY NIGHT...WHICH MAY BEGIN AS A BRIEF PERIOD
OF FROZEN PRECIPITATION ACROSS NORTHWEST MASSACHUSETTS.  A MUCH
STRONGER STORM PASSING WELL TO OUR WEST WEDNESDAY INTO CHRISTMAS
MORNING WILL BRING HEAVY RAIN...GUSTY WINDS AND MINOR COASTAL
FLOODING.  DRY WEATHER WITH ABOVE NORMAL TEMPERATURES EXPECTED
CHRISTMAS AFTERNOON INTO SATURDAY.  LOW PRESSURE MAY BRING A RETURN
TO UNSETTLED WEATHER BY WEDNESDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPPER LEVEL RIDGE BUILDS AHEAD OF DIGGING MIDWEST TROUGH WITH
HIGH PRESSURE REMAINING ANCHORED OVER THE CANADIAN MARITIMES
THROUGH TONIGHT.

EASTERLY FLOW WILL CONTINUE ONSHORE ALLOWING FOR THE PROFILE TO
CONTINUE TO MOISTEN IN THE LOW LEVELS. IF THIS MOISTURE DEEPENS
ENOUGH THEN WE COULD SEE LIGHT SHOWERS DEVELOP ESP ACROSS THE MASS
EAST COASTLINE. OTHERWISE DRIZZLE MAY BE THE MAIN FACTOR AS THE
UPPER LEVELS ARE FAIRLY DRY. OVERALL TODAY WILL BE A COOL AND CLOUDY
DAY WITH HIGHS ONLY REACHING IN THE UPPER 30S TO LOW 40S AS CROSS
SECTIONS ARE VERY MOIST IN THE LOW LEVELS.

&&

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

*LIGHT FREEZING RAIN IS POSSIBLE ACROSS THE INTERIOR NORTHWEST AND
  NORTHERN WORCESTER HILLS*

A WEAK AREA OF LOW PRESSURE DEVELOPS ALONG A WARM FRONT OFF THE MID
ATLANTIC...DRIFTING NORTHWARD TOWARD THE AREA. THIS LOW REMAINS WEAK
AS THE WARM FRONT MOVES SLOWLY NORTHWARD TONIGHT INTO TOMORROW.
DECENT WARM ADVECTION AHEAD OF THIS WAVE WITH SEVERAL HI-RES
GUIDANCE MODELS SHOWS A POTENTIAL FOR COLD AIR DAMMING ACROSS THE
INTERIOR INTO TUESDAY MORNING.  BIGGEST QUESTION WILL BE THE
MOISTURE POTENTIAL...IS THERE ENOUGH TO DEVELOP PRECIP ESP TONIGHT?
GUIDANCE DOES SHOW ENOUGH LIFT AHEAD OF APPROACHING SURFACE LOW PER
THE GFS/EC SO ANTICIPATE PRECIP TO DEVELOP AND OVERSPREAD ACROSS
SOUTHERN NEW ENGLAND. IF THIS PLAYS OUT WITH COLD AIR DAMMING AND
WARM AIR ADVECTION...THEN WE COULD SEE FREEZING RAIN/DRIZZLE ACROSS
THE INTERIOR NORTHWEST AND NORTHERN WORCESTER HILLS VERY LATE
TONIGHT INTO TUESDAY MORNING. A WINTER WEATHER ADVISORY MAY BE
NEEDED.

AS SURFACE LOW CONTINUES TO MOVE NORTHWARD...AND HIGH PRESSURE OVER
EASTERN CANADA...ANTICIPATE AN INCREASING LLJ. THIS SOUTHEASTERLY
JET WILL CONTINUE TO FEED MOISTURE INTO THE REGION AND WITH
SOUNDINGS SHOW A VERY SATURATED PROFILE COULD SEE NUMEROUS SHOWERS
WITH PERHAPS A FEW HEAVY DOWNPOURS. NOTICED GUIDANCE HAS
INCREASED THE QPF OVER THE PAST FEW DAYS. AS THE WEAK SURFACE LOW
MOVES NORTH OF SOUTHERN NEW ENGLAND...WARM FRONT WILL LIFT
NORTHWARD SO ALL PRECIP BY THE LATE MORNING WILL BE IN THE LIQUID
FORM.

WE COULD ALSO SEE SOME MINOR COASTAL FLOODING CONCERNS ON TUESDAY
WITH DUE EASTERLY FLOW INCREASING TO ABOUT 20 TO 25 MPH.  SEE BELOW
FOR MORE DETAILS.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...

HIGHLIGHTS...

* PERIODS OF RAIN TUE NIGHT INTO XMAS MORNING WILL BE HEAVY AT TIMES
* DRY BY XMAS AFTERNOON BUT WINDY
* TEMPS AROUND 60 FOR SOME LATE WED INTO CHRISTMAS MORNING
* DRY BUT ABOVE NORMAL TEMPS CONTINUE FRI AND SAT
* UNSETTLED WEATHER MAY RETURN BY SUN BUT LOW CONFIDENCE

DETAILS...

TUESDAY NIGHT INTO CHRISTMAS...

STRONG SHORTWAVE WILL DIG ACROSS THE CENTRAL U.S. AND ALLOW DEEP
SOUTH TO SOUTHWEST FLOW ALOFT ACROSS SOUTHERN NEW ENGLAND.  THIS
WILL SEND AND ANOMALOUS MILD AIRMASS INTO SOUTHERN NEW ENGLAND FOR
LATE DECEMBER.  GEFS SHOWING PWATS 4 TO 5 STANDARD DEVIATIONS ABOVE
NORMAL BY WED NIGHT ACROSS OUR REGION.  WHILE HEAVY RAIN IS STILL
EXPECTED...THE MODELS HAVE CUT DOWN ON THE QPF IN THE LAST FEW RUNS.
THE MAIN LOW STILL PASSES WELL TO OUR WEST ACROSS GREAT LAKES...BUT
THEIR SLOWER AND WEAKER WITH SECONDARY DEVELOPMENT ACROSS OUR
REGION.  THIS RESULTS IN A WEAKER LOW LEVEL JET...HENCE LESS QPF.
GIVEN ANOMALOUS PWATS IN PLACE...DO NOT WANT TO COMPLETELY LET OUR
GUARD DOWN WITH THE POTENTIAL FOR FLOODING...BUT DOES APPEAR
SOMEWHAT LESS OF A RISK THAN YESTERDAY.  NONETHELESS...STILL EXPECT
TYPICAL NUISANCE POOR DRAINAGE STREET FLOODING.

AS FOR TIMING...SOUTHERLY FLOW ALOFT WILL RESULT IN SCATTERED
SHOWERS TUE NIGHT.  BULK OF THE RAIN WILL OCCUR WED INTO EARLY
CHRISTMAS DAY WHEN STRONGEST FORCING COINCIDES HIGH PWAT AIRMASS.
SOME OF THIS RAIN WILL BE HEAVY AT TIMES MAY RESULT IN NUISANCE POOR
DRAINAGE STREET FLOODING.  STILL A LOW RISK FOR MORE SIGNIFICANT
FLOODING GIVEN EXTREMELY HIGH PWATS...BUT SLOWER DEVELOPMENT OF
SECONDARY LOW PRESSURE MAY BE A LIMITING FACTOR.  REGARDLESS...
EXPECT 1 TO 3 INCHES OF RAIN.  WILL CONTINUE TO MENTION A SLIGHT
CHANCE OF THUNDER WITH SHOWALTER INDICES NEAR ZERO.

THE BULK OF THE RAIN SHOULD COME TO AN END CHRISTMAS MORNING WITH
TEMPS PROBABLY AROUND 60 FOR MUCH OF THE REGION.  WHILE GUSTY
SOUTHERLY WINDS ARE EXPECTED WED NIGHT...INVERSION AND WEAKER LOW
LEVEL JET WILL PROBABLY KEEP MOST AREAS BELOW ADVISORY CRITERIA.
STILL HAVE TO WATCH FOR A SMALL WINDOW ON THE COASTAL PLAIN ESP IF
TEMPS CAN EXCEED 60...BUT HIGHER CONFIDENCE IN WIND ON CHRISTMAS
AFTERNOON AND EVENING BEHIND THE SYSTEM.  INCREASING WESTERLY WIND
ALOFT AND STEEPENING LAPSE RATES WILL BRING THE POTENTIAL FOR THESE
WINDS.  DECENT SHOT AT A PERIOD OF 35 TO 50 MPH GUSTS BEHIND THIS
SYSTEM CHRISTMAS AFTERNOON AND EVENING.  WHILE THE GFS IS AN
OUTLIER...IT WOULD EVEN SUGGEST THE POTENTIAL FOR HIGH WIND CRITERIA
TO BE MET WITH 70 KNOTS AT 850 MB.  THAT MAY BE OVERDONE...BUT
SOMETHING WILL HAVE TO KEEP AN EYE ON THE NEXT FEW DAYS.

FRIDAY AND SATURDAY...

UPPER LEVEL RIDGE OFF THE SOUTHEAST COAST WILL KEEP KEEP US IN MILD
SOUTHWEST FLOW ALOFT.  DRY WEATHER EXPECTED WITH FORCING FOR ANY
PRECIPITATION WILL TO OUR NORTHWEST.  HIGHS MAINLY IN THE 40S TO
LOWER 50S.

SUNDAY...

CONFIDENCE IN THE FORECAST GOES DOWN CONSIDERABLE OVER THIS TIME.
DEVELOPING UPPER LEVEL RIDGING INTO ALASKA WILL SEND THE POLAR JET
SOUTHWARD INTO THE CENTRAL U.S.  AT THE SAME TIME...UPPER LEVEL
RIDGE OFF THE SOUTHEAST COAST WILL TRY TO HANG TOUGH.  THE GFS
INSISTS ON DRY AND COLDER WEATHER ARRIVING...BUT WERE NOT CONVINCED.
GIVEN THE SOUTHEAST RIDGE IT MAY HOLD THE COLD AIR UP AND ALLOW
DEVELOPING LOW PRESSURE TO TRACK NEAR NEW ENGLAND SUN AND SUN NIGHT.
THIS COULD BRING RAIN OR SNOW DEPENDING ON ITS TRACK...OBVIOUSLY A
WEEK OUT SO PLENTY OF UNCERTAINTY BUT WOULD LEAN TOWARDS ANOTHER
SYSTEM AND AWAY FROM THE DRY GFS.

&&

.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 /THROUGH TUESDAY/...

TODAY...HIGH CONFIDENCE. DRIZZLE OR A FEW FLURRIES POSSIBLE
ACROSS EAST MASS TERMINALS. OTHERWISE ANY VFR CIGS WILL DROP TO
MVFR CONDITIONS THROUGHOUT THE DAY.

TONIGHT...MODERATE CONFIDENCE. MAINLY MVFR CONDITIONS CONTINUE IN
SCATTERED LIGHT SNOW SHOWERS. LIGHT FZRA POSSIBLE LATE MONDAY NIGHT
ACROSS NW MASSACHUSETTS.

TUESDAY...MODERATE CONFIDENCE. MVFR CONDITIONS MAY DROP TO IFR
WITHIN AND HEAVY RAIN FALL. VSBYS WILL BE REDUCED TO 5SM OR LESS
AS WELL.

KBOS TERMINAL...MODERATE CONFIDENCE. COULD SEE DRIZZLE LATER TODAY.

KBDL TERMINAL...MODERATE CONFIDENCE.

OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY...

TUESDAY NIGHT INTO THURSDAY MORNING...MODERATE CONFIDENCE.
WIDESPREAD LOW END MVFR TO IFR CONDITIONS EXPECTED IN PERIODS OF
HEAVY SHOWERS/LOW CLOUDS AND FOG PATCHES.  A PERIOD OF SOUTHERLY
WIND GUSTS OF 30 TO 40 KNOTS EXPECTED ON THE COASTAL PLAIN WED
NIGHT.  LLWS ALSO A CONCERN FOR THE ENTIRE REGION WED INTO EARLY THU.

THURSDAY AFTERNOON INTO FRIDAY...MODERATE TO HIGH CONFIDENCE IN
MAINLY VFR.  HOWEVER...A PERIOD OF WESTERLY 30 TO 45 KNOT WIND GUSTS
POSSIBLE THU AFTERNOON AND EVENING.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /THROUGH TUESDAY/...MODERATE TO HIGH CONFIDENCE.

HIGH PRESSURE ACROSS QUEBEC AND THE MARITIMES WILL RESULT IN
PERSISTENT NORTHEASTERLY TO EASTERLY WINDS ACROSS THE WATERS THROUGH
TODAY. THIS WILL BUILD SEAS TO 5FT ON THE EASTERN WATERS DESPITE
WIND GUSTS UP TO 20 KNOTS. HAVE CONTINUED SCA.

APPROACHING SURFACE LOW PRESSURE FROM THE MID-ATLANTIC TONIGHT WILL
HELP INCREASE AN EASTERLY LLJ OVER THE WATER TOMORROW. THIS WILL
BUILD THE SEAS BETWEEN 5-8 FT. COULD SEE WIND GUSTS BETWEEN 20-30
KTS AS THE FRONT PASSES. SCA HAS BEEN EXPANDED ACCORDINGLY.

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

TUESDAY NIGHT...LONG FETCH EASTERLY FLOW WILL CONTINUE TO RESULT IN
SCA SEAS ACROSS THE OUTER-WATERS WITH HIGH PRESSURE MOVING EAST OF
THE CANADIAN MARITIMES.  WINDS SHOULD GENERALLY BE BELOW SMALL CRAFT
THRESHOLDS.

WEDNESDAY INTO EARLY THURSDAY...INTENSIFYING LOW PRESSURE PASSING
WELL TO OUR WEST WILL CAUSE WINDS TO TURN SOUTHERLY AND BECOME
GUSTY. SMALL CRAFT WIND GUSTS ARE A LOCK.  THE MAIN UNCERTAINTY IS
DO WE SEE SOUTHERLY GALES DEVELOP WED NIGHT.  STRONG LOW LEVEL JET
PRESENT...BUT WE WILL BE DEALING WITH AN INVERSION OVER THE
RELATIVELY COOL OCEAN.  REGARDLESS...STILL SHOULD SEE AT LEAST A
PERIOD OF NEAR GALE FORCE SOUTHERLY WIND GUSTS.

LATER THURSDAY INTO FRIDAY...A PERIOD OF WESTERLY GALE FORCE WIND
GUSTS APPEARS LIKELY IN THE COLD ADVECTION PATTERN BEHIND THE STORM
THU AFTERNOON AND NIGHT.  WINDS SHOULD DIMINISH SOME ON FRIDAY.

&&

.TIDES/COASTAL FLOODING...


HIGH ASTRONOMICAL TIDES OCCUR TUE AND WED.

EAST MASSACHUSETTS COAST:

TUESDAY...HIGH TIDE AT BOSTON WILL BE 11.6 FT AT MIDDAY. WINDS WILL
BE FROM THE EAST AT 10 TO 15 KNOTS...SO THERE WILL BE ONSHORE FLOW
DURING THIS HIGH TIDE.  WHILE THIS IS NOTHING TOO STRONG...GIVEN THE
HIGH ASTRO TIDE EXPECT SOME SPLASH OVER/MINOR COASTAL FLOODING.
CERTAINLY DO NOT EXPECT TO SEE ANY SIGNIFICANT ISSUES.

WEDNESDAY...HIGH TIDE AT BOSTON WILL BE 11.7 FT AT MIDDAY.  WINDS
WILL BE FROM THE SOUTHEAST NEAR 10 KNOTS BUT THERE WILL BE SOME
PRESSURE FALLS WITH INTENSIFYING LOW PRESSURE TO OUR WEST.  THIS
SHOULD BE ENOUGH FOR MORE SPLASH OVER/MINOR COASTAL FLOODING WITH
THE HIGH ASTRO TIDES.  HOWEVER...DO NOT EXPECT ANY SIGNIFICANT
PROBLEMS GIVEN WINDS/SEAS SHOULD BE HELD IN CHECK DURING THE TIME OF
HIGH TIDE.

SOUTH COAST:

WEDNESDAY EVENING...SOUTHERLY WINDS ARE EXPECTED AND ASTRONOMICAL
TIDES INCREASE ALONG THE SOUTH COAST. HIGH TIDE IN PROVIDENCE WILL
BE 5.2 FT THAT EVENING. 925 MB LLJ STRENGTHENS TO 55-65 KTS WHICH
COULD PUSH A 1 TO 2 FOOT SURGE UP ALONG THE SOUTH COAST DURING THE
TIME OF HIGH TIDE.  THE LOW LEVEL INVERSION WILL PROBABLY HOLD THE
STRONGEST WINDS JUST ABOVE THE GROUND...SO THINKING THE RISK IS FOR
SPLASH OVER AND MINOR COASTAL FLOODING.  THERE STILL IS A LOW RISK
FOR MODERATE COASTAL FLOODING...BUT THAT IS OFTEN HARD TO GET IN A
NON-TROPICAL SYSTEM ALONG THE SOUTH COAST.


&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 1 AM TO 7 PM EST TUESDAY FOR ANZ231-
     232-251-256.
     SMALL CRAFT ADVISORY FROM 1 PM THIS AFTERNOON TO 7 PM EST
     TUESDAY FOR ANZ250-254.
     SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 7 PM EST
     TUESDAY FOR ANZ255.

&&

$$
SYNOPSIS...FRANK/DUNTEN
NEAR TERM...DUNTEN
SHORT TERM...DUNTEN
LONG TERM...FRANK
AVIATION...FRANK/DUNTEN
MARINE...FRANK/DUNTEN
TIDES/COASTAL FLOODING...FRANK




000
FXUS61 KBOX 220743
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
243 AM EST MON DEC 22 2014

.SYNOPSIS...
SCATTERED SNOW/RAIN SHOWERS WILL CONTINUE TODAY THANKS TO THE
ONSHORE FLOW. A WEAK LOW PRESSURE WILL MOVE ACROSS NEW ENGLAND
BRINGING A PERIOD OF PRECIPITATION VERY LATE MONDAY NIGHT AND
INTO TUESDAY. A MUCH STRONGER STORM PASSING WEST OF NEW ENGLAND
WILL BRING HEAVY RAINFALL...GUSTY WINDS AND COASTAL FLOODING
CONCERNS TO THE REGION WEDNESDAY AND WEDNESDAY NIGHT. DRY BUT VERY
WINDY CONDITIONS FOLLOW FOR CHRISTMAS DAY. HIGH PRESSURE BRINGS
DRY WEATHER FRIDAY. ANOTHER DEVELOPING SYSTEM MAY BRING RAIN AND
SNOW NEXT SUNDAY.

&&

.NEAR TERM /THROUGH TODAY/...

UPPER LEVEL RIDGE BUILDS AHEAD OF DIGGING MIDWEST TROUGH WITH
HIGH PRESSURE REMAINING ANCHORED OVER THE CANADIAN MARITIMES
THROUGH TONIGHT.

EASTERLY FLOW WILL CONTINUE ONSHORE ALLOWING FOR THE PROFILE TO
CONTINUE TO MOISTEN IN THE LOW LEVELS. IF THIS MOISTURE DEEPENS
ENOUGH THEN WE COULD SEE LIGHT SHOWERS DEVELOP ESP ACROSS THE MASS
EAST COASTLINE. OTHERWISE DRIZZLE MAY BE THE MAIN FACTOR AS THE
UPPER LEVELS ARE FAIRLY DRY. OVERALL TODAY WILL BE A COOL AND CLOUDY
DAY WITH HIGHS ONLY REACHING IN THE UPPER 30S TO LOW 40S AS CROSS
SECTIONS ARE VERY MOIST IN THE LOW LEVELS.

&&

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

TONIGHT INTO TOMORROW...

*LIGHT FREEZING RAIN IS POSSIBLE ACROSS THE INTERIOR NORTHWEST AND
  NORTHERN WORCESTER HILLS*

A WEAK AREA OF LOW PRESSURE DEVELOPS ALONG A WARM FRONT OFF THE MID
ATLANTIC...DRIFTING NORTHWARD TOWARD THE AREA. THIS LOW REMAINS WEAK
AS THE WARM FRONT MOVES SLOWLY NORTHWARD TONIGHT INTO TOMORROW.
DECENT WARM ADVECTION AHEAD OF THIS WAVE WITH SEVERAL HI-RES
GUIDANCE MODELS SHOWS A POTENTIAL FOR COLD AIR DAMMING ACROSS THE
INTERIOR INTO TUESDAY MORNING.  BIGGEST QUESTION WILL BE THE
MOISTURE POTENTIAL...IS THERE ENOUGH TO DEVELOP PRECIP ESP TONIGHT?
GUIDANCE DOES SHOW ENOUGH LIFT AHEAD OF APPROACHING SURFACE LOW PER
THE GFS/EC SO ANTICIPATE PRECIP TO DEVELOP AND OVERSPREAD ACROSS
SOUTHERN NEW ENGLAND. IF THIS PLAYS OUT WITH COLD AIR DAMMING AND
WARM AIR ADVECTION...THEN WE COULD SEE FREEZING RAIN/DRIZZLE ACROSS
THE INTERIOR NORTHWEST AND NORTHERN WORCESTER HILLS VERY LATE
TONIGHT INTO TUESDAY MORNING. A WINTER WEATHER ADVISORY MAY BE
NEEDED.

AS SURFACE LOW CONTINUES TO MOVE NORTHWARD...AND HIGH PRESSURE OVER
EASTERN CANADA...ANTICIPATE AN INCREASING LLJ. THIS SOUTHEASTERLY
JET WILL CONTINUE TO FEED MOISTURE INTO THE REGION AND WITH
SOUNDINGS SHOW A VERY SATURATED PROFILE COULD SEE NUMEROUS SHOWERS
WITH PERHAPS A FEW HEAVY DOWNPOURS. NOTICED GUIDANCE HAS
INCREASED THE QPF OVER THE PAST FEW DAYS. AS THE WEAK SURFACE LOW
MOVES NORTH OF SOUTHERN NEW ENGLAND...WARM FRONT WILL LIFT
NORTHWARD SO ALL PRECIP BY THE LATE MORNING WILL BE IN THE LIQUID
FORM.

WE COULD ALSO SEE SOME MINOR COASTAL FLOODING CONCERNS ON TUESDAY
WITH DUE EASTERLY FLOW INCREASING TO ABOUT 20 TO 25 MPH.  SEE BELOW
FOR MORE DETAILS.


&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
BIG PICTURE...

TUESDAY STARTS WITH UPPER RIDGES ON EACH COAST AND A DEEP UPPER
TROUGH/CLOSED LOW OVER THE PLAINS. BY WEDNESDAY THE CLOSED LOW
EJECTS NORTHEAST THROUGH LAKE SUPERIOR INTO CANADA. THIS SWEEPS THE
TROUGH AXIS EAST AND PASSES ACROSS NEW ENGLAND CHRISTMAS DAY.
ANOTHER SHORTWAVE MOVES ONSHORE IN THE PACIFIC NORTHWEST WEDNESDAY
AND PHASES WITH A SECOND DROPPING SOUTH FROM NORTHERN CANADA.  THIS
REESTABLISHES THE UPPER TROUGH OVER THE NORTHERN PLAINS/GREAT LAKES
SATURDAY.

CONTOUR HEIGHTS WILL BE ABOVE NORMAL MIDWEEK...TRENDING BELOW NORMAL
OVER THE WEEKEND AS THE SECOND UPPER TROUGH SHIFTS EAST. THIS POINTS
TO A COOLING TREND AFTER CHRISTMAS.

THE GFS AND ECMWF ARE SIMILAR IN HANDLING THE HOLIDAY STORM. THERE
ARE DIFFERENCES BETWEEN THE MODELS IN HANDLING THE SUNDAY SYSTEM. WE
USED A BLEND MOST OF THE LONG TERM PERIOD...BUT MANUALLY ADJUSTED
POPS FOR SUNDAY WITH LOW CONFIDENCE IN MODEL VALUES.

THE DAILIES...

TUESDAY... HIGH PRESSURE OVER THE MARITIMES WITH RIDGING DOWN THE
ATLANTIC COAST. COASTAL LOW PRESSURE WAVE DEVELOPS ALONG STALLED
WARM FRONT AND MOVES NORTH.  AS THE COASTAL LOW MOVES NORTH IT WILL
RUN UP AGAINST THE MARITIME HIGH. THIS WILL INCREASE THE LOW LEVEL
PRESSURE GRADIENT AND INCREASE THE LOW LEVEL SOUTHEAST WINDS.
RESULT...A SOUTHEAST LOW LEVEL JET RUNS OVER THE RIDGING ALONG THE
COASTAL PLAIN INDUCING LOW LEVEL LIFT. THE MOIST LAYER EXPANDS ABOVE
800 MB...NOT DEEP BUT DEEP ENOUGH FOR THE LIFT TO GENERATE LIGHT
PCPN. PTYPE WILL BE RAIN MOST PLACES...BUT THERE COULD BE SPOTS OF
LIGHT FREEZING RAIN IN NORTHWEST MASSACHUSETTS. WE WILL MAINTAIN
CHANCE POPS BUT INCREASE TO AROUND 50 PCT...THE HIGH END OF THE
CHANCE RANGE.

LOW LEVEL SOUTH JET MOVES UP THE COAST TUESDAY NIGHT REACHING THE
COOLER AIR OVER NEW ENGLAND AFTER MIDNIGHT AND BEFORE SUNRISE. THIS
WILL GENERATE ADDITIONAL LIFT AS WELL AS INCREASING AND DEEPENING
MOISTURE. THIS SUGGESTS INCREASING POPS OVERNIGHT.  TEMPERATURES
SHOULD REMAIN ABOVE FREEZING SO PTYPE SHOULD BE RAIN.

WEDNESDAY-THURSDAY... SOUTH 40-50 KNOT LOW LEVEL JET MOVES OVER NEW
ENGLAND WEDNESDAY GENERATING STRONG LIFT AND TRANSPORTING HIGH
VALUES OF PRECIPITABLE WATER INTO THAT LIFT. THE MOISTURE VALUES ARE
MORE THAN 3 STD DEVIATIONS ABOVE NORMAL FOR DECEMBER...AND ACTUALLY
NEAR THE MAXIMUM PREVIOUSLY OBSERVED VALUE. THIS SUGGESTS RAIN WITH
SOME HEAVY DOWNPOURS. COLD FRONT APPROACHES LATE WEDNESDAY NIGHT AND
CROSSES SOUTHERN NEW ENGLAND CHRISTMAS MORNING. THE FRONT WILL HAVE
DYNAMIC SUPPORT FROM A 140-150 KNOT UPPER JET. THE FOREWARD PROGRESS
OF THE FRONT WILL SLOW BECAUSE MOST OF THE MOTION IN THE UPPER JET
WILL BE PARALLEL TO THE FRONT. THIS WILL MEAN CONTINUED RAIN/HEAVY
RAIN THROUGH THE NIGHT INTO THURSDAY MORNING.

THE OBVIOUS CONCERN FOR THIS PERIOD WILL BE FLOODING FROM HEAVY
RAINFALL. RAIN AMOUNTS OF 2 TO 3 INCHES ARE EXPECTED. THIS SHOULD BE
SUFFICIENT FOR AT LEAST URBAN AND POOR DRAINAGE FLOODING. A FLOOD
WATCH MAY BE NEEDED.

A SECOND CONCERN WILL BE WIND. THE LOW LEVEL JET WEDNESDAY WILL BE
SOUTH 40-50 KNOTS...AND INCREASE TO 55-65 KNOTS WEDNESDAY NIGHT.
CONVENTIONAL MIXING WILL NOT BE DEEP...BUT HEAVY DOWNPOURS COULD
CREATE A MOIST ADIABATIC CHANNEL THAT BRINGS DOWN SOME STRONGER WIND
GUSTS. MODEL GRIDS ARE RATHER LIGHT ON WIND GUSTS...15 TO 30 KNOTS.
WE WILL MANUALLY ADJUST THESE VALUES UP TO 25-35 KNOTS OVER LAND AND
A LITTLE STRONGER OVER WATER.

A THIRD CONCERN WILL BE COASTAL FLOODING. MORE DETAILS ON THIS IN
THE TIDE/COASTAL FLOOD SECTION.

WINDS SHIFT TO WEST BEHIND THE FRONT ON CHRISTMAS DAY. THIS WILL
BRING DRIER AIR AND SO END THE RAINFALL. COLD ADVECTION WILL PROMOTE
MIXING TO NEAR 850 MB IN THE AFTERNOON AND TAP 25-35 KNOT WIND
GUSTS...POSSIBLY 40 KNOT GUSTS. A WIND ADVISORY MAY BE NEEDED FOR
THESE WEST WINDS THURSDAY.

FRIDAY THROUGH SUNDAY.... HIGH PRESSURE MOVES OVER THE REGION FRIDAY
BRINGING DRY WEATHER.  SHORTWAVE MOVING THROUGH THE GREAT LAKES
SWINGS A COLD FRONT THROUGH NEW ENGLAND SATURDAY. THE SURFACE
REFLECTION OF THE SHORTWAVE MOVES UP THE ST LAWRENCE VALLEY AND JET
SUPPORT WILL MOSTLY BE NORTH OF THE BORDER...SO PCPN WILL BE
LIMITED. QUESTION FOR SUNDAY WILL BE WHETHER A WAVE FORMS ON THE
DEPARTING COLD FRONT...IF SO IT MIGHT BRING PCPN TO NEW ENGLAND.
THE ECMWF THINKS SO BUT THE GFS DOES NOT. WE BROUGHT IN A CHANCE
OF RAIN AND SNOW SHOWERS.

&&

.AVIATION /08Z MONDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /THROUGH TUESDAY/...

TODAY...HIGH CONFIDENCE. DRIZZLE OR A FEW FLURRIES POSSIBLE
ACROSS EAST MASS TERMINALS. OTHERWISE ANY VFR CIGS WILL DROP TO
MVFR CONDITIONS THROUGHOUT THE DAY.

TONIGHT...MODERATE CONFIDENCE. MAINLY MVFR CONDITIONS CONTINUE IN
SCATTERED LIGHT SNOW SHOWERS. LIGHT FZRA POSSIBLE LATE MONDAY NIGHT
ACROSS NW MASSACHUSETTS.

TUESDAY...MODERATE CONFIDENCE. MVFR CONDITIONS MAY DROP TO IFR
WITHIN AND HEAVY RAIN FALL. VSBYS WILL BE REDUCED TO 5SM OR LESS
AS WELL.

KBOS TERMINAL...MODERATE CONFIDENCE. COULD SEE DRIZZLE LATER TODAY.

KBDL TERMINAL...MODERATE CONFIDENCE.

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

LATE TUESDAY NIGHT-WEDNESDAY-THURSDAY... CONDITIONS LOWERING TO
IFR/LIFR IN RAIN/HEAVY RAIN. SOUTHEAST WINDS GUSTING 25 TO 35
KNOTS WEDNESDAY AND SOUTH WINDS SIMILAR SPEEDS WEDNESDAY
NIGHT...EXCEPT 30 TO 40 KNOTS CAPE COD AND ISLANDS. WINDS AT 2000
FEET MAY REACH 55 TO 65 KNOTS BY WEDNESDAY NIGHT CREATING LOW
LEVEL WIND SHEAR. ISOLATED THUNDERSTORMS WEDNESDAY AFTERNOON AND
NIGHT. COLD FRONT SWINGS THROUGH ON THURSDAY MORNING BRINGING A
WIND SHIFT TO WEST WITH GUSTS 30-40 KNOTS. CONDITIONS IMPROVE TO
VFR AFTER THE WIND SHIFT.

FRIDAY...VFR.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /THROUGH TUESDAY/...MODERATE TO HIGH CONFIDENCE.

HIGH PRESSURE ACROSS QUEBEC AND THE MARITIMES WILL RESULT IN
PERSISTENT NORTHEASTERLY TO EASTERLY WINDS ACROSS THE WATERS THROUGH
TODAY. THIS WILL BUILD SEAS TO 5FT ON THE EASTERN WATERS DESPITE
WIND GUSTS UP TO 20 KNOTS. HAVE CONTINUED SCA.

APPROACHING SURFACE LOW PRESSURE FROM THE MID-ATLANTIC TONIGHT WILL
HELP INCREASE AN EASTERLY LLJ OVER THE WATER TOMORROW. THIS WILL
BUILD THE SEAS BETWEEN 5-8 FT. COULD SEE WIND GUSTS BETWEEN 20-30
KTS AS THE FRONT PASSES. SCA HAS BEEN EXPANDED ACCORDINGLY.

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

WEDNESDAY-THURSDAY... SOUTH WINDS WITH FREQUENT GUSTS 35 TO 40
KNOTS BY WEDNESDAY AFTERNOON AND CONTINUING THROUGH THE NIGHT.
WINDS SHIFT WEST THURSDAY MORNING WITH SIMILAR SPEEDS THROUGH THE
AFTERNOON. SEAS WILL BUILD TO 7 TO 12 FEET ON THE EXPOSED WATERS
BY WEDNESDAY NIGHT AND THURSDAY. A GALE WARNING MAY BE NEEDED.

FRIDAY...WINDS DIMINISHING TO 25 KNOTS FRIDAY MORNING AND BELOW 25
KNOTS BY AFTERNOON.  SEAS LINGERING AT 5 TO 7 FEET ON THE EXPOSED
WATERS. A SMALL CRAFT ADVISORY MAY BE NEEDED.

&&

.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES WILL OCCUR TUESDAY THROUGH THURSDAY.

TUESDAY...HIGH TIDE AT BOSTON WILL BE 11.6 FT. WINDS WILL BE FROM
THE EAST...SO THERE WILL BE ONSHORE FLOW DURING THIS HIGH TIDE
ALLOWING FOR MINOR SPLASHOVER. IF WINDS INCREASE THEN COULD SEE
SOME POCKETS OF MINOR COASTAL FLOODING.

WEDNESDAY...WINDS SHIFT TO A MORE SOUTHEASTERLY FLOW DURING THE DAY
AND INCREASE QUICKLY AS AN APPROACHING SYSTEM BRINGS PRESSURE
FALLS OF 1 MB/HR. THE WEDNESDAY AFTERNOON HIGH TIDE IN BOSTON IS
11.7 FT AND STRONG SOUTHEASTERLY WINDS WILL BE JUST OFFSHORE.
RIGHT NOW BELIEVE MINOR COASTAL FLOODING IS POSSIBLE ALONG THE
EAST COAST.

WEDNESDAY EVENING...SOUTHERLY WINDS ARE EXPECTED AND ASTRONOMICAL
TIDES INCREASE ALONG THE SOUTH COAST. HIGH TIDE IN PROVIDENCE WILL
BE 5.2 FT. 925 MB LLJ STRENGTHENS TO 55-65 KTS WHICH COULD PUSH A
DECENT SURGE UP ALONG THE SOUTH COAST DURING THE TIME OF HIGH
TIDE. THINKING THAT MINOR COASTAL FLOODING COULD OCCUR BUT CANNOT
RULE OUT MODERATE ALONG THE SOUTH COAST...ESPECIALLY IF LLJ
CONTINUES TO STRENGTHEN.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 7 AM EST
     TUESDAY FOR ANZ250.
     SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 7 AM EST
     TUESDAY FOR ANZ251-255.
     SMALL CRAFT ADVISORY FROM 1 PM THIS AFTERNOON TO 7 AM EST
     TUESDAY FOR ANZ254.

&&

$$
SYNOPSIS...WTB/DUNTEN
NEAR TERM...DUNTEN
SHORT TERM...DUNTEN
LONG TERM...WTB
AVIATION...WTB/DUNTEN
MARINE...WTB/DUNTEN
TIDES/COASTAL FLOODING...





000
FXUS61 KBOX 220743
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
243 AM EST MON DEC 22 2014

.SYNOPSIS...
SCATTERED SNOW/RAIN SHOWERS WILL CONTINUE TODAY THANKS TO THE
ONSHORE FLOW. A WEAK LOW PRESSURE WILL MOVE ACROSS NEW ENGLAND
BRINGING A PERIOD OF PRECIPITATION VERY LATE MONDAY NIGHT AND
INTO TUESDAY. A MUCH STRONGER STORM PASSING WEST OF NEW ENGLAND
WILL BRING HEAVY RAINFALL...GUSTY WINDS AND COASTAL FLOODING
CONCERNS TO THE REGION WEDNESDAY AND WEDNESDAY NIGHT. DRY BUT VERY
WINDY CONDITIONS FOLLOW FOR CHRISTMAS DAY. HIGH PRESSURE BRINGS
DRY WEATHER FRIDAY. ANOTHER DEVELOPING SYSTEM MAY BRING RAIN AND
SNOW NEXT SUNDAY.

&&

.NEAR TERM /THROUGH TODAY/...

UPPER LEVEL RIDGE BUILDS AHEAD OF DIGGING MIDWEST TROUGH WITH
HIGH PRESSURE REMAINING ANCHORED OVER THE CANADIAN MARITIMES
THROUGH TONIGHT.

EASTERLY FLOW WILL CONTINUE ONSHORE ALLOWING FOR THE PROFILE TO
CONTINUE TO MOISTEN IN THE LOW LEVELS. IF THIS MOISTURE DEEPENS
ENOUGH THEN WE COULD SEE LIGHT SHOWERS DEVELOP ESP ACROSS THE MASS
EAST COASTLINE. OTHERWISE DRIZZLE MAY BE THE MAIN FACTOR AS THE
UPPER LEVELS ARE FAIRLY DRY. OVERALL TODAY WILL BE A COOL AND CLOUDY
DAY WITH HIGHS ONLY REACHING IN THE UPPER 30S TO LOW 40S AS CROSS
SECTIONS ARE VERY MOIST IN THE LOW LEVELS.

&&

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

TONIGHT INTO TOMORROW...

*LIGHT FREEZING RAIN IS POSSIBLE ACROSS THE INTERIOR NORTHWEST AND
  NORTHERN WORCESTER HILLS*

A WEAK AREA OF LOW PRESSURE DEVELOPS ALONG A WARM FRONT OFF THE MID
ATLANTIC...DRIFTING NORTHWARD TOWARD THE AREA. THIS LOW REMAINS WEAK
AS THE WARM FRONT MOVES SLOWLY NORTHWARD TONIGHT INTO TOMORROW.
DECENT WARM ADVECTION AHEAD OF THIS WAVE WITH SEVERAL HI-RES
GUIDANCE MODELS SHOWS A POTENTIAL FOR COLD AIR DAMMING ACROSS THE
INTERIOR INTO TUESDAY MORNING.  BIGGEST QUESTION WILL BE THE
MOISTURE POTENTIAL...IS THERE ENOUGH TO DEVELOP PRECIP ESP TONIGHT?
GUIDANCE DOES SHOW ENOUGH LIFT AHEAD OF APPROACHING SURFACE LOW PER
THE GFS/EC SO ANTICIPATE PRECIP TO DEVELOP AND OVERSPREAD ACROSS
SOUTHERN NEW ENGLAND. IF THIS PLAYS OUT WITH COLD AIR DAMMING AND
WARM AIR ADVECTION...THEN WE COULD SEE FREEZING RAIN/DRIZZLE ACROSS
THE INTERIOR NORTHWEST AND NORTHERN WORCESTER HILLS VERY LATE
TONIGHT INTO TUESDAY MORNING. A WINTER WEATHER ADVISORY MAY BE
NEEDED.

AS SURFACE LOW CONTINUES TO MOVE NORTHWARD...AND HIGH PRESSURE OVER
EASTERN CANADA...ANTICIPATE AN INCREASING LLJ. THIS SOUTHEASTERLY
JET WILL CONTINUE TO FEED MOISTURE INTO THE REGION AND WITH
SOUNDINGS SHOW A VERY SATURATED PROFILE COULD SEE NUMEROUS SHOWERS
WITH PERHAPS A FEW HEAVY DOWNPOURS. NOTICED GUIDANCE HAS
INCREASED THE QPF OVER THE PAST FEW DAYS. AS THE WEAK SURFACE LOW
MOVES NORTH OF SOUTHERN NEW ENGLAND...WARM FRONT WILL LIFT
NORTHWARD SO ALL PRECIP BY THE LATE MORNING WILL BE IN THE LIQUID
FORM.

WE COULD ALSO SEE SOME MINOR COASTAL FLOODING CONCERNS ON TUESDAY
WITH DUE EASTERLY FLOW INCREASING TO ABOUT 20 TO 25 MPH.  SEE BELOW
FOR MORE DETAILS.


&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
BIG PICTURE...

TUESDAY STARTS WITH UPPER RIDGES ON EACH COAST AND A DEEP UPPER
TROUGH/CLOSED LOW OVER THE PLAINS. BY WEDNESDAY THE CLOSED LOW
EJECTS NORTHEAST THROUGH LAKE SUPERIOR INTO CANADA. THIS SWEEPS THE
TROUGH AXIS EAST AND PASSES ACROSS NEW ENGLAND CHRISTMAS DAY.
ANOTHER SHORTWAVE MOVES ONSHORE IN THE PACIFIC NORTHWEST WEDNESDAY
AND PHASES WITH A SECOND DROPPING SOUTH FROM NORTHERN CANADA.  THIS
REESTABLISHES THE UPPER TROUGH OVER THE NORTHERN PLAINS/GREAT LAKES
SATURDAY.

CONTOUR HEIGHTS WILL BE ABOVE NORMAL MIDWEEK...TRENDING BELOW NORMAL
OVER THE WEEKEND AS THE SECOND UPPER TROUGH SHIFTS EAST. THIS POINTS
TO A COOLING TREND AFTER CHRISTMAS.

THE GFS AND ECMWF ARE SIMILAR IN HANDLING THE HOLIDAY STORM. THERE
ARE DIFFERENCES BETWEEN THE MODELS IN HANDLING THE SUNDAY SYSTEM. WE
USED A BLEND MOST OF THE LONG TERM PERIOD...BUT MANUALLY ADJUSTED
POPS FOR SUNDAY WITH LOW CONFIDENCE IN MODEL VALUES.

THE DAILIES...

TUESDAY... HIGH PRESSURE OVER THE MARITIMES WITH RIDGING DOWN THE
ATLANTIC COAST. COASTAL LOW PRESSURE WAVE DEVELOPS ALONG STALLED
WARM FRONT AND MOVES NORTH.  AS THE COASTAL LOW MOVES NORTH IT WILL
RUN UP AGAINST THE MARITIME HIGH. THIS WILL INCREASE THE LOW LEVEL
PRESSURE GRADIENT AND INCREASE THE LOW LEVEL SOUTHEAST WINDS.
RESULT...A SOUTHEAST LOW LEVEL JET RUNS OVER THE RIDGING ALONG THE
COASTAL PLAIN INDUCING LOW LEVEL LIFT. THE MOIST LAYER EXPANDS ABOVE
800 MB...NOT DEEP BUT DEEP ENOUGH FOR THE LIFT TO GENERATE LIGHT
PCPN. PTYPE WILL BE RAIN MOST PLACES...BUT THERE COULD BE SPOTS OF
LIGHT FREEZING RAIN IN NORTHWEST MASSACHUSETTS. WE WILL MAINTAIN
CHANCE POPS BUT INCREASE TO AROUND 50 PCT...THE HIGH END OF THE
CHANCE RANGE.

LOW LEVEL SOUTH JET MOVES UP THE COAST TUESDAY NIGHT REACHING THE
COOLER AIR OVER NEW ENGLAND AFTER MIDNIGHT AND BEFORE SUNRISE. THIS
WILL GENERATE ADDITIONAL LIFT AS WELL AS INCREASING AND DEEPENING
MOISTURE. THIS SUGGESTS INCREASING POPS OVERNIGHT.  TEMPERATURES
SHOULD REMAIN ABOVE FREEZING SO PTYPE SHOULD BE RAIN.

WEDNESDAY-THURSDAY... SOUTH 40-50 KNOT LOW LEVEL JET MOVES OVER NEW
ENGLAND WEDNESDAY GENERATING STRONG LIFT AND TRANSPORTING HIGH
VALUES OF PRECIPITABLE WATER INTO THAT LIFT. THE MOISTURE VALUES ARE
MORE THAN 3 STD DEVIATIONS ABOVE NORMAL FOR DECEMBER...AND ACTUALLY
NEAR THE MAXIMUM PREVIOUSLY OBSERVED VALUE. THIS SUGGESTS RAIN WITH
SOME HEAVY DOWNPOURS. COLD FRONT APPROACHES LATE WEDNESDAY NIGHT AND
CROSSES SOUTHERN NEW ENGLAND CHRISTMAS MORNING. THE FRONT WILL HAVE
DYNAMIC SUPPORT FROM A 140-150 KNOT UPPER JET. THE FOREWARD PROGRESS
OF THE FRONT WILL SLOW BECAUSE MOST OF THE MOTION IN THE UPPER JET
WILL BE PARALLEL TO THE FRONT. THIS WILL MEAN CONTINUED RAIN/HEAVY
RAIN THROUGH THE NIGHT INTO THURSDAY MORNING.

THE OBVIOUS CONCERN FOR THIS PERIOD WILL BE FLOODING FROM HEAVY
RAINFALL. RAIN AMOUNTS OF 2 TO 3 INCHES ARE EXPECTED. THIS SHOULD BE
SUFFICIENT FOR AT LEAST URBAN AND POOR DRAINAGE FLOODING. A FLOOD
WATCH MAY BE NEEDED.

A SECOND CONCERN WILL BE WIND. THE LOW LEVEL JET WEDNESDAY WILL BE
SOUTH 40-50 KNOTS...AND INCREASE TO 55-65 KNOTS WEDNESDAY NIGHT.
CONVENTIONAL MIXING WILL NOT BE DEEP...BUT HEAVY DOWNPOURS COULD
CREATE A MOIST ADIABATIC CHANNEL THAT BRINGS DOWN SOME STRONGER WIND
GUSTS. MODEL GRIDS ARE RATHER LIGHT ON WIND GUSTS...15 TO 30 KNOTS.
WE WILL MANUALLY ADJUST THESE VALUES UP TO 25-35 KNOTS OVER LAND AND
A LITTLE STRONGER OVER WATER.

A THIRD CONCERN WILL BE COASTAL FLOODING. MORE DETAILS ON THIS IN
THE TIDE/COASTAL FLOOD SECTION.

WINDS SHIFT TO WEST BEHIND THE FRONT ON CHRISTMAS DAY. THIS WILL
BRING DRIER AIR AND SO END THE RAINFALL. COLD ADVECTION WILL PROMOTE
MIXING TO NEAR 850 MB IN THE AFTERNOON AND TAP 25-35 KNOT WIND
GUSTS...POSSIBLY 40 KNOT GUSTS. A WIND ADVISORY MAY BE NEEDED FOR
THESE WEST WINDS THURSDAY.

FRIDAY THROUGH SUNDAY.... HIGH PRESSURE MOVES OVER THE REGION FRIDAY
BRINGING DRY WEATHER.  SHORTWAVE MOVING THROUGH THE GREAT LAKES
SWINGS A COLD FRONT THROUGH NEW ENGLAND SATURDAY. THE SURFACE
REFLECTION OF THE SHORTWAVE MOVES UP THE ST LAWRENCE VALLEY AND JET
SUPPORT WILL MOSTLY BE NORTH OF THE BORDER...SO PCPN WILL BE
LIMITED. QUESTION FOR SUNDAY WILL BE WHETHER A WAVE FORMS ON THE
DEPARTING COLD FRONT...IF SO IT MIGHT BRING PCPN TO NEW ENGLAND.
THE ECMWF THINKS SO BUT THE GFS DOES NOT. WE BROUGHT IN A CHANCE
OF RAIN AND SNOW SHOWERS.

&&

.AVIATION /08Z MONDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /THROUGH TUESDAY/...

TODAY...HIGH CONFIDENCE. DRIZZLE OR A FEW FLURRIES POSSIBLE
ACROSS EAST MASS TERMINALS. OTHERWISE ANY VFR CIGS WILL DROP TO
MVFR CONDITIONS THROUGHOUT THE DAY.

TONIGHT...MODERATE CONFIDENCE. MAINLY MVFR CONDITIONS CONTINUE IN
SCATTERED LIGHT SNOW SHOWERS. LIGHT FZRA POSSIBLE LATE MONDAY NIGHT
ACROSS NW MASSACHUSETTS.

TUESDAY...MODERATE CONFIDENCE. MVFR CONDITIONS MAY DROP TO IFR
WITHIN AND HEAVY RAIN FALL. VSBYS WILL BE REDUCED TO 5SM OR LESS
AS WELL.

KBOS TERMINAL...MODERATE CONFIDENCE. COULD SEE DRIZZLE LATER TODAY.

KBDL TERMINAL...MODERATE CONFIDENCE.

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

LATE TUESDAY NIGHT-WEDNESDAY-THURSDAY... CONDITIONS LOWERING TO
IFR/LIFR IN RAIN/HEAVY RAIN. SOUTHEAST WINDS GUSTING 25 TO 35
KNOTS WEDNESDAY AND SOUTH WINDS SIMILAR SPEEDS WEDNESDAY
NIGHT...EXCEPT 30 TO 40 KNOTS CAPE COD AND ISLANDS. WINDS AT 2000
FEET MAY REACH 55 TO 65 KNOTS BY WEDNESDAY NIGHT CREATING LOW
LEVEL WIND SHEAR. ISOLATED THUNDERSTORMS WEDNESDAY AFTERNOON AND
NIGHT. COLD FRONT SWINGS THROUGH ON THURSDAY MORNING BRINGING A
WIND SHIFT TO WEST WITH GUSTS 30-40 KNOTS. CONDITIONS IMPROVE TO
VFR AFTER THE WIND SHIFT.

FRIDAY...VFR.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /THROUGH TUESDAY/...MODERATE TO HIGH CONFIDENCE.

HIGH PRESSURE ACROSS QUEBEC AND THE MARITIMES WILL RESULT IN
PERSISTENT NORTHEASTERLY TO EASTERLY WINDS ACROSS THE WATERS THROUGH
TODAY. THIS WILL BUILD SEAS TO 5FT ON THE EASTERN WATERS DESPITE
WIND GUSTS UP TO 20 KNOTS. HAVE CONTINUED SCA.

APPROACHING SURFACE LOW PRESSURE FROM THE MID-ATLANTIC TONIGHT WILL
HELP INCREASE AN EASTERLY LLJ OVER THE WATER TOMORROW. THIS WILL
BUILD THE SEAS BETWEEN 5-8 FT. COULD SEE WIND GUSTS BETWEEN 20-30
KTS AS THE FRONT PASSES. SCA HAS BEEN EXPANDED ACCORDINGLY.

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

WEDNESDAY-THURSDAY... SOUTH WINDS WITH FREQUENT GUSTS 35 TO 40
KNOTS BY WEDNESDAY AFTERNOON AND CONTINUING THROUGH THE NIGHT.
WINDS SHIFT WEST THURSDAY MORNING WITH SIMILAR SPEEDS THROUGH THE
AFTERNOON. SEAS WILL BUILD TO 7 TO 12 FEET ON THE EXPOSED WATERS
BY WEDNESDAY NIGHT AND THURSDAY. A GALE WARNING MAY BE NEEDED.

FRIDAY...WINDS DIMINISHING TO 25 KNOTS FRIDAY MORNING AND BELOW 25
KNOTS BY AFTERNOON.  SEAS LINGERING AT 5 TO 7 FEET ON THE EXPOSED
WATERS. A SMALL CRAFT ADVISORY MAY BE NEEDED.

&&

.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES WILL OCCUR TUESDAY THROUGH THURSDAY.

TUESDAY...HIGH TIDE AT BOSTON WILL BE 11.6 FT. WINDS WILL BE FROM
THE EAST...SO THERE WILL BE ONSHORE FLOW DURING THIS HIGH TIDE
ALLOWING FOR MINOR SPLASHOVER. IF WINDS INCREASE THEN COULD SEE
SOME POCKETS OF MINOR COASTAL FLOODING.

WEDNESDAY...WINDS SHIFT TO A MORE SOUTHEASTERLY FLOW DURING THE DAY
AND INCREASE QUICKLY AS AN APPROACHING SYSTEM BRINGS PRESSURE
FALLS OF 1 MB/HR. THE WEDNESDAY AFTERNOON HIGH TIDE IN BOSTON IS
11.7 FT AND STRONG SOUTHEASTERLY WINDS WILL BE JUST OFFSHORE.
RIGHT NOW BELIEVE MINOR COASTAL FLOODING IS POSSIBLE ALONG THE
EAST COAST.

WEDNESDAY EVENING...SOUTHERLY WINDS ARE EXPECTED AND ASTRONOMICAL
TIDES INCREASE ALONG THE SOUTH COAST. HIGH TIDE IN PROVIDENCE WILL
BE 5.2 FT. 925 MB LLJ STRENGTHENS TO 55-65 KTS WHICH COULD PUSH A
DECENT SURGE UP ALONG THE SOUTH COAST DURING THE TIME OF HIGH
TIDE. THINKING THAT MINOR COASTAL FLOODING COULD OCCUR BUT CANNOT
RULE OUT MODERATE ALONG THE SOUTH COAST...ESPECIALLY IF LLJ
CONTINUES TO STRENGTHEN.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 7 AM EST
     TUESDAY FOR ANZ250.
     SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 7 AM EST
     TUESDAY FOR ANZ251-255.
     SMALL CRAFT ADVISORY FROM 1 PM THIS AFTERNOON TO 7 AM EST
     TUESDAY FOR ANZ254.

&&

$$
SYNOPSIS...WTB/DUNTEN
NEAR TERM...DUNTEN
SHORT TERM...DUNTEN
LONG TERM...WTB
AVIATION...WTB/DUNTEN
MARINE...WTB/DUNTEN
TIDES/COASTAL FLOODING...





000
FXUS61 KBOX 220743
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
243 AM EST MON DEC 22 2014

.SYNOPSIS...
SCATTERED SNOW/RAIN SHOWERS WILL CONTINUE TODAY THANKS TO THE
ONSHORE FLOW. A WEAK LOW PRESSURE WILL MOVE ACROSS NEW ENGLAND
BRINGING A PERIOD OF PRECIPITATION VERY LATE MONDAY NIGHT AND
INTO TUESDAY. A MUCH STRONGER STORM PASSING WEST OF NEW ENGLAND
WILL BRING HEAVY RAINFALL...GUSTY WINDS AND COASTAL FLOODING
CONCERNS TO THE REGION WEDNESDAY AND WEDNESDAY NIGHT. DRY BUT VERY
WINDY CONDITIONS FOLLOW FOR CHRISTMAS DAY. HIGH PRESSURE BRINGS
DRY WEATHER FRIDAY. ANOTHER DEVELOPING SYSTEM MAY BRING RAIN AND
SNOW NEXT SUNDAY.

&&

.NEAR TERM /THROUGH TODAY/...

UPPER LEVEL RIDGE BUILDS AHEAD OF DIGGING MIDWEST TROUGH WITH
HIGH PRESSURE REMAINING ANCHORED OVER THE CANADIAN MARITIMES
THROUGH TONIGHT.

EASTERLY FLOW WILL CONTINUE ONSHORE ALLOWING FOR THE PROFILE TO
CONTINUE TO MOISTEN IN THE LOW LEVELS. IF THIS MOISTURE DEEPENS
ENOUGH THEN WE COULD SEE LIGHT SHOWERS DEVELOP ESP ACROSS THE MASS
EAST COASTLINE. OTHERWISE DRIZZLE MAY BE THE MAIN FACTOR AS THE
UPPER LEVELS ARE FAIRLY DRY. OVERALL TODAY WILL BE A COOL AND CLOUDY
DAY WITH HIGHS ONLY REACHING IN THE UPPER 30S TO LOW 40S AS CROSS
SECTIONS ARE VERY MOIST IN THE LOW LEVELS.

&&

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

TONIGHT INTO TOMORROW...

*LIGHT FREEZING RAIN IS POSSIBLE ACROSS THE INTERIOR NORTHWEST AND
  NORTHERN WORCESTER HILLS*

A WEAK AREA OF LOW PRESSURE DEVELOPS ALONG A WARM FRONT OFF THE MID
ATLANTIC...DRIFTING NORTHWARD TOWARD THE AREA. THIS LOW REMAINS WEAK
AS THE WARM FRONT MOVES SLOWLY NORTHWARD TONIGHT INTO TOMORROW.
DECENT WARM ADVECTION AHEAD OF THIS WAVE WITH SEVERAL HI-RES
GUIDANCE MODELS SHOWS A POTENTIAL FOR COLD AIR DAMMING ACROSS THE
INTERIOR INTO TUESDAY MORNING.  BIGGEST QUESTION WILL BE THE
MOISTURE POTENTIAL...IS THERE ENOUGH TO DEVELOP PRECIP ESP TONIGHT?
GUIDANCE DOES SHOW ENOUGH LIFT AHEAD OF APPROACHING SURFACE LOW PER
THE GFS/EC SO ANTICIPATE PRECIP TO DEVELOP AND OVERSPREAD ACROSS
SOUTHERN NEW ENGLAND. IF THIS PLAYS OUT WITH COLD AIR DAMMING AND
WARM AIR ADVECTION...THEN WE COULD SEE FREEZING RAIN/DRIZZLE ACROSS
THE INTERIOR NORTHWEST AND NORTHERN WORCESTER HILLS VERY LATE
TONIGHT INTO TUESDAY MORNING. A WINTER WEATHER ADVISORY MAY BE
NEEDED.

AS SURFACE LOW CONTINUES TO MOVE NORTHWARD...AND HIGH PRESSURE OVER
EASTERN CANADA...ANTICIPATE AN INCREASING LLJ. THIS SOUTHEASTERLY
JET WILL CONTINUE TO FEED MOISTURE INTO THE REGION AND WITH
SOUNDINGS SHOW A VERY SATURATED PROFILE COULD SEE NUMEROUS SHOWERS
WITH PERHAPS A FEW HEAVY DOWNPOURS. NOTICED GUIDANCE HAS
INCREASED THE QPF OVER THE PAST FEW DAYS. AS THE WEAK SURFACE LOW
MOVES NORTH OF SOUTHERN NEW ENGLAND...WARM FRONT WILL LIFT
NORTHWARD SO ALL PRECIP BY THE LATE MORNING WILL BE IN THE LIQUID
FORM.

WE COULD ALSO SEE SOME MINOR COASTAL FLOODING CONCERNS ON TUESDAY
WITH DUE EASTERLY FLOW INCREASING TO ABOUT 20 TO 25 MPH.  SEE BELOW
FOR MORE DETAILS.


&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
BIG PICTURE...

TUESDAY STARTS WITH UPPER RIDGES ON EACH COAST AND A DEEP UPPER
TROUGH/CLOSED LOW OVER THE PLAINS. BY WEDNESDAY THE CLOSED LOW
EJECTS NORTHEAST THROUGH LAKE SUPERIOR INTO CANADA. THIS SWEEPS THE
TROUGH AXIS EAST AND PASSES ACROSS NEW ENGLAND CHRISTMAS DAY.
ANOTHER SHORTWAVE MOVES ONSHORE IN THE PACIFIC NORTHWEST WEDNESDAY
AND PHASES WITH A SECOND DROPPING SOUTH FROM NORTHERN CANADA.  THIS
REESTABLISHES THE UPPER TROUGH OVER THE NORTHERN PLAINS/GREAT LAKES
SATURDAY.

CONTOUR HEIGHTS WILL BE ABOVE NORMAL MIDWEEK...TRENDING BELOW NORMAL
OVER THE WEEKEND AS THE SECOND UPPER TROUGH SHIFTS EAST. THIS POINTS
TO A COOLING TREND AFTER CHRISTMAS.

THE GFS AND ECMWF ARE SIMILAR IN HANDLING THE HOLIDAY STORM. THERE
ARE DIFFERENCES BETWEEN THE MODELS IN HANDLING THE SUNDAY SYSTEM. WE
USED A BLEND MOST OF THE LONG TERM PERIOD...BUT MANUALLY ADJUSTED
POPS FOR SUNDAY WITH LOW CONFIDENCE IN MODEL VALUES.

THE DAILIES...

TUESDAY... HIGH PRESSURE OVER THE MARITIMES WITH RIDGING DOWN THE
ATLANTIC COAST. COASTAL LOW PRESSURE WAVE DEVELOPS ALONG STALLED
WARM FRONT AND MOVES NORTH.  AS THE COASTAL LOW MOVES NORTH IT WILL
RUN UP AGAINST THE MARITIME HIGH. THIS WILL INCREASE THE LOW LEVEL
PRESSURE GRADIENT AND INCREASE THE LOW LEVEL SOUTHEAST WINDS.
RESULT...A SOUTHEAST LOW LEVEL JET RUNS OVER THE RIDGING ALONG THE
COASTAL PLAIN INDUCING LOW LEVEL LIFT. THE MOIST LAYER EXPANDS ABOVE
800 MB...NOT DEEP BUT DEEP ENOUGH FOR THE LIFT TO GENERATE LIGHT
PCPN. PTYPE WILL BE RAIN MOST PLACES...BUT THERE COULD BE SPOTS OF
LIGHT FREEZING RAIN IN NORTHWEST MASSACHUSETTS. WE WILL MAINTAIN
CHANCE POPS BUT INCREASE TO AROUND 50 PCT...THE HIGH END OF THE
CHANCE RANGE.

LOW LEVEL SOUTH JET MOVES UP THE COAST TUESDAY NIGHT REACHING THE
COOLER AIR OVER NEW ENGLAND AFTER MIDNIGHT AND BEFORE SUNRISE. THIS
WILL GENERATE ADDITIONAL LIFT AS WELL AS INCREASING AND DEEPENING
MOISTURE. THIS SUGGESTS INCREASING POPS OVERNIGHT.  TEMPERATURES
SHOULD REMAIN ABOVE FREEZING SO PTYPE SHOULD BE RAIN.

WEDNESDAY-THURSDAY... SOUTH 40-50 KNOT LOW LEVEL JET MOVES OVER NEW
ENGLAND WEDNESDAY GENERATING STRONG LIFT AND TRANSPORTING HIGH
VALUES OF PRECIPITABLE WATER INTO THAT LIFT. THE MOISTURE VALUES ARE
MORE THAN 3 STD DEVIATIONS ABOVE NORMAL FOR DECEMBER...AND ACTUALLY
NEAR THE MAXIMUM PREVIOUSLY OBSERVED VALUE. THIS SUGGESTS RAIN WITH
SOME HEAVY DOWNPOURS. COLD FRONT APPROACHES LATE WEDNESDAY NIGHT AND
CROSSES SOUTHERN NEW ENGLAND CHRISTMAS MORNING. THE FRONT WILL HAVE
DYNAMIC SUPPORT FROM A 140-150 KNOT UPPER JET. THE FOREWARD PROGRESS
OF THE FRONT WILL SLOW BECAUSE MOST OF THE MOTION IN THE UPPER JET
WILL BE PARALLEL TO THE FRONT. THIS WILL MEAN CONTINUED RAIN/HEAVY
RAIN THROUGH THE NIGHT INTO THURSDAY MORNING.

THE OBVIOUS CONCERN FOR THIS PERIOD WILL BE FLOODING FROM HEAVY
RAINFALL. RAIN AMOUNTS OF 2 TO 3 INCHES ARE EXPECTED. THIS SHOULD BE
SUFFICIENT FOR AT LEAST URBAN AND POOR DRAINAGE FLOODING. A FLOOD
WATCH MAY BE NEEDED.

A SECOND CONCERN WILL BE WIND. THE LOW LEVEL JET WEDNESDAY WILL BE
SOUTH 40-50 KNOTS...AND INCREASE TO 55-65 KNOTS WEDNESDAY NIGHT.
CONVENTIONAL MIXING WILL NOT BE DEEP...BUT HEAVY DOWNPOURS COULD
CREATE A MOIST ADIABATIC CHANNEL THAT BRINGS DOWN SOME STRONGER WIND
GUSTS. MODEL GRIDS ARE RATHER LIGHT ON WIND GUSTS...15 TO 30 KNOTS.
WE WILL MANUALLY ADJUST THESE VALUES UP TO 25-35 KNOTS OVER LAND AND
A LITTLE STRONGER OVER WATER.

A THIRD CONCERN WILL BE COASTAL FLOODING. MORE DETAILS ON THIS IN
THE TIDE/COASTAL FLOOD SECTION.

WINDS SHIFT TO WEST BEHIND THE FRONT ON CHRISTMAS DAY. THIS WILL
BRING DRIER AIR AND SO END THE RAINFALL. COLD ADVECTION WILL PROMOTE
MIXING TO NEAR 850 MB IN THE AFTERNOON AND TAP 25-35 KNOT WIND
GUSTS...POSSIBLY 40 KNOT GUSTS. A WIND ADVISORY MAY BE NEEDED FOR
THESE WEST WINDS THURSDAY.

FRIDAY THROUGH SUNDAY.... HIGH PRESSURE MOVES OVER THE REGION FRIDAY
BRINGING DRY WEATHER.  SHORTWAVE MOVING THROUGH THE GREAT LAKES
SWINGS A COLD FRONT THROUGH NEW ENGLAND SATURDAY. THE SURFACE
REFLECTION OF THE SHORTWAVE MOVES UP THE ST LAWRENCE VALLEY AND JET
SUPPORT WILL MOSTLY BE NORTH OF THE BORDER...SO PCPN WILL BE
LIMITED. QUESTION FOR SUNDAY WILL BE WHETHER A WAVE FORMS ON THE
DEPARTING COLD FRONT...IF SO IT MIGHT BRING PCPN TO NEW ENGLAND.
THE ECMWF THINKS SO BUT THE GFS DOES NOT. WE BROUGHT IN A CHANCE
OF RAIN AND SNOW SHOWERS.

&&

.AVIATION /08Z MONDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /THROUGH TUESDAY/...

TODAY...HIGH CONFIDENCE. DRIZZLE OR A FEW FLURRIES POSSIBLE
ACROSS EAST MASS TERMINALS. OTHERWISE ANY VFR CIGS WILL DROP TO
MVFR CONDITIONS THROUGHOUT THE DAY.

TONIGHT...MODERATE CONFIDENCE. MAINLY MVFR CONDITIONS CONTINUE IN
SCATTERED LIGHT SNOW SHOWERS. LIGHT FZRA POSSIBLE LATE MONDAY NIGHT
ACROSS NW MASSACHUSETTS.

TUESDAY...MODERATE CONFIDENCE. MVFR CONDITIONS MAY DROP TO IFR
WITHIN AND HEAVY RAIN FALL. VSBYS WILL BE REDUCED TO 5SM OR LESS
AS WELL.

KBOS TERMINAL...MODERATE CONFIDENCE. COULD SEE DRIZZLE LATER TODAY.

KBDL TERMINAL...MODERATE CONFIDENCE.

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

LATE TUESDAY NIGHT-WEDNESDAY-THURSDAY... CONDITIONS LOWERING TO
IFR/LIFR IN RAIN/HEAVY RAIN. SOUTHEAST WINDS GUSTING 25 TO 35
KNOTS WEDNESDAY AND SOUTH WINDS SIMILAR SPEEDS WEDNESDAY
NIGHT...EXCEPT 30 TO 40 KNOTS CAPE COD AND ISLANDS. WINDS AT 2000
FEET MAY REACH 55 TO 65 KNOTS BY WEDNESDAY NIGHT CREATING LOW
LEVEL WIND SHEAR. ISOLATED THUNDERSTORMS WEDNESDAY AFTERNOON AND
NIGHT. COLD FRONT SWINGS THROUGH ON THURSDAY MORNING BRINGING A
WIND SHIFT TO WEST WITH GUSTS 30-40 KNOTS. CONDITIONS IMPROVE TO
VFR AFTER THE WIND SHIFT.

FRIDAY...VFR.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /THROUGH TUESDAY/...MODERATE TO HIGH CONFIDENCE.

HIGH PRESSURE ACROSS QUEBEC AND THE MARITIMES WILL RESULT IN
PERSISTENT NORTHEASTERLY TO EASTERLY WINDS ACROSS THE WATERS THROUGH
TODAY. THIS WILL BUILD SEAS TO 5FT ON THE EASTERN WATERS DESPITE
WIND GUSTS UP TO 20 KNOTS. HAVE CONTINUED SCA.

APPROACHING SURFACE LOW PRESSURE FROM THE MID-ATLANTIC TONIGHT WILL
HELP INCREASE AN EASTERLY LLJ OVER THE WATER TOMORROW. THIS WILL
BUILD THE SEAS BETWEEN 5-8 FT. COULD SEE WIND GUSTS BETWEEN 20-30
KTS AS THE FRONT PASSES. SCA HAS BEEN EXPANDED ACCORDINGLY.

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

WEDNESDAY-THURSDAY... SOUTH WINDS WITH FREQUENT GUSTS 35 TO 40
KNOTS BY WEDNESDAY AFTERNOON AND CONTINUING THROUGH THE NIGHT.
WINDS SHIFT WEST THURSDAY MORNING WITH SIMILAR SPEEDS THROUGH THE
AFTERNOON. SEAS WILL BUILD TO 7 TO 12 FEET ON THE EXPOSED WATERS
BY WEDNESDAY NIGHT AND THURSDAY. A GALE WARNING MAY BE NEEDED.

FRIDAY...WINDS DIMINISHING TO 25 KNOTS FRIDAY MORNING AND BELOW 25
KNOTS BY AFTERNOON.  SEAS LINGERING AT 5 TO 7 FEET ON THE EXPOSED
WATERS. A SMALL CRAFT ADVISORY MAY BE NEEDED.

&&

.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES WILL OCCUR TUESDAY THROUGH THURSDAY.

TUESDAY...HIGH TIDE AT BOSTON WILL BE 11.6 FT. WINDS WILL BE FROM
THE EAST...SO THERE WILL BE ONSHORE FLOW DURING THIS HIGH TIDE
ALLOWING FOR MINOR SPLASHOVER. IF WINDS INCREASE THEN COULD SEE
SOME POCKETS OF MINOR COASTAL FLOODING.

WEDNESDAY...WINDS SHIFT TO A MORE SOUTHEASTERLY FLOW DURING THE DAY
AND INCREASE QUICKLY AS AN APPROACHING SYSTEM BRINGS PRESSURE
FALLS OF 1 MB/HR. THE WEDNESDAY AFTERNOON HIGH TIDE IN BOSTON IS
11.7 FT AND STRONG SOUTHEASTERLY WINDS WILL BE JUST OFFSHORE.
RIGHT NOW BELIEVE MINOR COASTAL FLOODING IS POSSIBLE ALONG THE
EAST COAST.

WEDNESDAY EVENING...SOUTHERLY WINDS ARE EXPECTED AND ASTRONOMICAL
TIDES INCREASE ALONG THE SOUTH COAST. HIGH TIDE IN PROVIDENCE WILL
BE 5.2 FT. 925 MB LLJ STRENGTHENS TO 55-65 KTS WHICH COULD PUSH A
DECENT SURGE UP ALONG THE SOUTH COAST DURING THE TIME OF HIGH
TIDE. THINKING THAT MINOR COASTAL FLOODING COULD OCCUR BUT CANNOT
RULE OUT MODERATE ALONG THE SOUTH COAST...ESPECIALLY IF LLJ
CONTINUES TO STRENGTHEN.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 7 AM EST
     TUESDAY FOR ANZ250.
     SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 7 AM EST
     TUESDAY FOR ANZ251-255.
     SMALL CRAFT ADVISORY FROM 1 PM THIS AFTERNOON TO 7 AM EST
     TUESDAY FOR ANZ254.

&&

$$
SYNOPSIS...WTB/DUNTEN
NEAR TERM...DUNTEN
SHORT TERM...DUNTEN
LONG TERM...WTB
AVIATION...WTB/DUNTEN
MARINE...WTB/DUNTEN
TIDES/COASTAL FLOODING...




000
FXUS61 KBOX 220743
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
243 AM EST MON DEC 22 2014

.SYNOPSIS...
SCATTERED SNOW/RAIN SHOWERS WILL CONTINUE TODAY THANKS TO THE
ONSHORE FLOW. A WEAK LOW PRESSURE WILL MOVE ACROSS NEW ENGLAND
BRINGING A PERIOD OF PRECIPITATION VERY LATE MONDAY NIGHT AND
INTO TUESDAY. A MUCH STRONGER STORM PASSING WEST OF NEW ENGLAND
WILL BRING HEAVY RAINFALL...GUSTY WINDS AND COASTAL FLOODING
CONCERNS TO THE REGION WEDNESDAY AND WEDNESDAY NIGHT. DRY BUT VERY
WINDY CONDITIONS FOLLOW FOR CHRISTMAS DAY. HIGH PRESSURE BRINGS
DRY WEATHER FRIDAY. ANOTHER DEVELOPING SYSTEM MAY BRING RAIN AND
SNOW NEXT SUNDAY.

&&

.NEAR TERM /THROUGH TODAY/...

UPPER LEVEL RIDGE BUILDS AHEAD OF DIGGING MIDWEST TROUGH WITH
HIGH PRESSURE REMAINING ANCHORED OVER THE CANADIAN MARITIMES
THROUGH TONIGHT.

EASTERLY FLOW WILL CONTINUE ONSHORE ALLOWING FOR THE PROFILE TO
CONTINUE TO MOISTEN IN THE LOW LEVELS. IF THIS MOISTURE DEEPENS
ENOUGH THEN WE COULD SEE LIGHT SHOWERS DEVELOP ESP ACROSS THE MASS
EAST COASTLINE. OTHERWISE DRIZZLE MAY BE THE MAIN FACTOR AS THE
UPPER LEVELS ARE FAIRLY DRY. OVERALL TODAY WILL BE A COOL AND CLOUDY
DAY WITH HIGHS ONLY REACHING IN THE UPPER 30S TO LOW 40S AS CROSS
SECTIONS ARE VERY MOIST IN THE LOW LEVELS.

&&

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

TONIGHT INTO TOMORROW...

*LIGHT FREEZING RAIN IS POSSIBLE ACROSS THE INTERIOR NORTHWEST AND
  NORTHERN WORCESTER HILLS*

A WEAK AREA OF LOW PRESSURE DEVELOPS ALONG A WARM FRONT OFF THE MID
ATLANTIC...DRIFTING NORTHWARD TOWARD THE AREA. THIS LOW REMAINS WEAK
AS THE WARM FRONT MOVES SLOWLY NORTHWARD TONIGHT INTO TOMORROW.
DECENT WARM ADVECTION AHEAD OF THIS WAVE WITH SEVERAL HI-RES
GUIDANCE MODELS SHOWS A POTENTIAL FOR COLD AIR DAMMING ACROSS THE
INTERIOR INTO TUESDAY MORNING.  BIGGEST QUESTION WILL BE THE
MOISTURE POTENTIAL...IS THERE ENOUGH TO DEVELOP PRECIP ESP TONIGHT?
GUIDANCE DOES SHOW ENOUGH LIFT AHEAD OF APPROACHING SURFACE LOW PER
THE GFS/EC SO ANTICIPATE PRECIP TO DEVELOP AND OVERSPREAD ACROSS
SOUTHERN NEW ENGLAND. IF THIS PLAYS OUT WITH COLD AIR DAMMING AND
WARM AIR ADVECTION...THEN WE COULD SEE FREEZING RAIN/DRIZZLE ACROSS
THE INTERIOR NORTHWEST AND NORTHERN WORCESTER HILLS VERY LATE
TONIGHT INTO TUESDAY MORNING. A WINTER WEATHER ADVISORY MAY BE
NEEDED.

AS SURFACE LOW CONTINUES TO MOVE NORTHWARD...AND HIGH PRESSURE OVER
EASTERN CANADA...ANTICIPATE AN INCREASING LLJ. THIS SOUTHEASTERLY
JET WILL CONTINUE TO FEED MOISTURE INTO THE REGION AND WITH
SOUNDINGS SHOW A VERY SATURATED PROFILE COULD SEE NUMEROUS SHOWERS
WITH PERHAPS A FEW HEAVY DOWNPOURS. NOTICED GUIDANCE HAS
INCREASED THE QPF OVER THE PAST FEW DAYS. AS THE WEAK SURFACE LOW
MOVES NORTH OF SOUTHERN NEW ENGLAND...WARM FRONT WILL LIFT
NORTHWARD SO ALL PRECIP BY THE LATE MORNING WILL BE IN THE LIQUID
FORM.

WE COULD ALSO SEE SOME MINOR COASTAL FLOODING CONCERNS ON TUESDAY
WITH DUE EASTERLY FLOW INCREASING TO ABOUT 20 TO 25 MPH.  SEE BELOW
FOR MORE DETAILS.


&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
BIG PICTURE...

TUESDAY STARTS WITH UPPER RIDGES ON EACH COAST AND A DEEP UPPER
TROUGH/CLOSED LOW OVER THE PLAINS. BY WEDNESDAY THE CLOSED LOW
EJECTS NORTHEAST THROUGH LAKE SUPERIOR INTO CANADA. THIS SWEEPS THE
TROUGH AXIS EAST AND PASSES ACROSS NEW ENGLAND CHRISTMAS DAY.
ANOTHER SHORTWAVE MOVES ONSHORE IN THE PACIFIC NORTHWEST WEDNESDAY
AND PHASES WITH A SECOND DROPPING SOUTH FROM NORTHERN CANADA.  THIS
REESTABLISHES THE UPPER TROUGH OVER THE NORTHERN PLAINS/GREAT LAKES
SATURDAY.

CONTOUR HEIGHTS WILL BE ABOVE NORMAL MIDWEEK...TRENDING BELOW NORMAL
OVER THE WEEKEND AS THE SECOND UPPER TROUGH SHIFTS EAST. THIS POINTS
TO A COOLING TREND AFTER CHRISTMAS.

THE GFS AND ECMWF ARE SIMILAR IN HANDLING THE HOLIDAY STORM. THERE
ARE DIFFERENCES BETWEEN THE MODELS IN HANDLING THE SUNDAY SYSTEM. WE
USED A BLEND MOST OF THE LONG TERM PERIOD...BUT MANUALLY ADJUSTED
POPS FOR SUNDAY WITH LOW CONFIDENCE IN MODEL VALUES.

THE DAILIES...

TUESDAY... HIGH PRESSURE OVER THE MARITIMES WITH RIDGING DOWN THE
ATLANTIC COAST. COASTAL LOW PRESSURE WAVE DEVELOPS ALONG STALLED
WARM FRONT AND MOVES NORTH.  AS THE COASTAL LOW MOVES NORTH IT WILL
RUN UP AGAINST THE MARITIME HIGH. THIS WILL INCREASE THE LOW LEVEL
PRESSURE GRADIENT AND INCREASE THE LOW LEVEL SOUTHEAST WINDS.
RESULT...A SOUTHEAST LOW LEVEL JET RUNS OVER THE RIDGING ALONG THE
COASTAL PLAIN INDUCING LOW LEVEL LIFT. THE MOIST LAYER EXPANDS ABOVE
800 MB...NOT DEEP BUT DEEP ENOUGH FOR THE LIFT TO GENERATE LIGHT
PCPN. PTYPE WILL BE RAIN MOST PLACES...BUT THERE COULD BE SPOTS OF
LIGHT FREEZING RAIN IN NORTHWEST MASSACHUSETTS. WE WILL MAINTAIN
CHANCE POPS BUT INCREASE TO AROUND 50 PCT...THE HIGH END OF THE
CHANCE RANGE.

LOW LEVEL SOUTH JET MOVES UP THE COAST TUESDAY NIGHT REACHING THE
COOLER AIR OVER NEW ENGLAND AFTER MIDNIGHT AND BEFORE SUNRISE. THIS
WILL GENERATE ADDITIONAL LIFT AS WELL AS INCREASING AND DEEPENING
MOISTURE. THIS SUGGESTS INCREASING POPS OVERNIGHT.  TEMPERATURES
SHOULD REMAIN ABOVE FREEZING SO PTYPE SHOULD BE RAIN.

WEDNESDAY-THURSDAY... SOUTH 40-50 KNOT LOW LEVEL JET MOVES OVER NEW
ENGLAND WEDNESDAY GENERATING STRONG LIFT AND TRANSPORTING HIGH
VALUES OF PRECIPITABLE WATER INTO THAT LIFT. THE MOISTURE VALUES ARE
MORE THAN 3 STD DEVIATIONS ABOVE NORMAL FOR DECEMBER...AND ACTUALLY
NEAR THE MAXIMUM PREVIOUSLY OBSERVED VALUE. THIS SUGGESTS RAIN WITH
SOME HEAVY DOWNPOURS. COLD FRONT APPROACHES LATE WEDNESDAY NIGHT AND
CROSSES SOUTHERN NEW ENGLAND CHRISTMAS MORNING. THE FRONT WILL HAVE
DYNAMIC SUPPORT FROM A 140-150 KNOT UPPER JET. THE FOREWARD PROGRESS
OF THE FRONT WILL SLOW BECAUSE MOST OF THE MOTION IN THE UPPER JET
WILL BE PARALLEL TO THE FRONT. THIS WILL MEAN CONTINUED RAIN/HEAVY
RAIN THROUGH THE NIGHT INTO THURSDAY MORNING.

THE OBVIOUS CONCERN FOR THIS PERIOD WILL BE FLOODING FROM HEAVY
RAINFALL. RAIN AMOUNTS OF 2 TO 3 INCHES ARE EXPECTED. THIS SHOULD BE
SUFFICIENT FOR AT LEAST URBAN AND POOR DRAINAGE FLOODING. A FLOOD
WATCH MAY BE NEEDED.

A SECOND CONCERN WILL BE WIND. THE LOW LEVEL JET WEDNESDAY WILL BE
SOUTH 40-50 KNOTS...AND INCREASE TO 55-65 KNOTS WEDNESDAY NIGHT.
CONVENTIONAL MIXING WILL NOT BE DEEP...BUT HEAVY DOWNPOURS COULD
CREATE A MOIST ADIABATIC CHANNEL THAT BRINGS DOWN SOME STRONGER WIND
GUSTS. MODEL GRIDS ARE RATHER LIGHT ON WIND GUSTS...15 TO 30 KNOTS.
WE WILL MANUALLY ADJUST THESE VALUES UP TO 25-35 KNOTS OVER LAND AND
A LITTLE STRONGER OVER WATER.

A THIRD CONCERN WILL BE COASTAL FLOODING. MORE DETAILS ON THIS IN
THE TIDE/COASTAL FLOOD SECTION.

WINDS SHIFT TO WEST BEHIND THE FRONT ON CHRISTMAS DAY. THIS WILL
BRING DRIER AIR AND SO END THE RAINFALL. COLD ADVECTION WILL PROMOTE
MIXING TO NEAR 850 MB IN THE AFTERNOON AND TAP 25-35 KNOT WIND
GUSTS...POSSIBLY 40 KNOT GUSTS. A WIND ADVISORY MAY BE NEEDED FOR
THESE WEST WINDS THURSDAY.

FRIDAY THROUGH SUNDAY.... HIGH PRESSURE MOVES OVER THE REGION FRIDAY
BRINGING DRY WEATHER.  SHORTWAVE MOVING THROUGH THE GREAT LAKES
SWINGS A COLD FRONT THROUGH NEW ENGLAND SATURDAY. THE SURFACE
REFLECTION OF THE SHORTWAVE MOVES UP THE ST LAWRENCE VALLEY AND JET
SUPPORT WILL MOSTLY BE NORTH OF THE BORDER...SO PCPN WILL BE
LIMITED. QUESTION FOR SUNDAY WILL BE WHETHER A WAVE FORMS ON THE
DEPARTING COLD FRONT...IF SO IT MIGHT BRING PCPN TO NEW ENGLAND.
THE ECMWF THINKS SO BUT THE GFS DOES NOT. WE BROUGHT IN A CHANCE
OF RAIN AND SNOW SHOWERS.

&&

.AVIATION /08Z MONDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /THROUGH TUESDAY/...

TODAY...HIGH CONFIDENCE. DRIZZLE OR A FEW FLURRIES POSSIBLE
ACROSS EAST MASS TERMINALS. OTHERWISE ANY VFR CIGS WILL DROP TO
MVFR CONDITIONS THROUGHOUT THE DAY.

TONIGHT...MODERATE CONFIDENCE. MAINLY MVFR CONDITIONS CONTINUE IN
SCATTERED LIGHT SNOW SHOWERS. LIGHT FZRA POSSIBLE LATE MONDAY NIGHT
ACROSS NW MASSACHUSETTS.

TUESDAY...MODERATE CONFIDENCE. MVFR CONDITIONS MAY DROP TO IFR
WITHIN AND HEAVY RAIN FALL. VSBYS WILL BE REDUCED TO 5SM OR LESS
AS WELL.

KBOS TERMINAL...MODERATE CONFIDENCE. COULD SEE DRIZZLE LATER TODAY.

KBDL TERMINAL...MODERATE CONFIDENCE.

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

LATE TUESDAY NIGHT-WEDNESDAY-THURSDAY... CONDITIONS LOWERING TO
IFR/LIFR IN RAIN/HEAVY RAIN. SOUTHEAST WINDS GUSTING 25 TO 35
KNOTS WEDNESDAY AND SOUTH WINDS SIMILAR SPEEDS WEDNESDAY
NIGHT...EXCEPT 30 TO 40 KNOTS CAPE COD AND ISLANDS. WINDS AT 2000
FEET MAY REACH 55 TO 65 KNOTS BY WEDNESDAY NIGHT CREATING LOW
LEVEL WIND SHEAR. ISOLATED THUNDERSTORMS WEDNESDAY AFTERNOON AND
NIGHT. COLD FRONT SWINGS THROUGH ON THURSDAY MORNING BRINGING A
WIND SHIFT TO WEST WITH GUSTS 30-40 KNOTS. CONDITIONS IMPROVE TO
VFR AFTER THE WIND SHIFT.

FRIDAY...VFR.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /THROUGH TUESDAY/...MODERATE TO HIGH CONFIDENCE.

HIGH PRESSURE ACROSS QUEBEC AND THE MARITIMES WILL RESULT IN
PERSISTENT NORTHEASTERLY TO EASTERLY WINDS ACROSS THE WATERS THROUGH
TODAY. THIS WILL BUILD SEAS TO 5FT ON THE EASTERN WATERS DESPITE
WIND GUSTS UP TO 20 KNOTS. HAVE CONTINUED SCA.

APPROACHING SURFACE LOW PRESSURE FROM THE MID-ATLANTIC TONIGHT WILL
HELP INCREASE AN EASTERLY LLJ OVER THE WATER TOMORROW. THIS WILL
BUILD THE SEAS BETWEEN 5-8 FT. COULD SEE WIND GUSTS BETWEEN 20-30
KTS AS THE FRONT PASSES. SCA HAS BEEN EXPANDED ACCORDINGLY.

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

WEDNESDAY-THURSDAY... SOUTH WINDS WITH FREQUENT GUSTS 35 TO 40
KNOTS BY WEDNESDAY AFTERNOON AND CONTINUING THROUGH THE NIGHT.
WINDS SHIFT WEST THURSDAY MORNING WITH SIMILAR SPEEDS THROUGH THE
AFTERNOON. SEAS WILL BUILD TO 7 TO 12 FEET ON THE EXPOSED WATERS
BY WEDNESDAY NIGHT AND THURSDAY. A GALE WARNING MAY BE NEEDED.

FRIDAY...WINDS DIMINISHING TO 25 KNOTS FRIDAY MORNING AND BELOW 25
KNOTS BY AFTERNOON.  SEAS LINGERING AT 5 TO 7 FEET ON THE EXPOSED
WATERS. A SMALL CRAFT ADVISORY MAY BE NEEDED.

&&

.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES WILL OCCUR TUESDAY THROUGH THURSDAY.

TUESDAY...HIGH TIDE AT BOSTON WILL BE 11.6 FT. WINDS WILL BE FROM
THE EAST...SO THERE WILL BE ONSHORE FLOW DURING THIS HIGH TIDE
ALLOWING FOR MINOR SPLASHOVER. IF WINDS INCREASE THEN COULD SEE
SOME POCKETS OF MINOR COASTAL FLOODING.

WEDNESDAY...WINDS SHIFT TO A MORE SOUTHEASTERLY FLOW DURING THE DAY
AND INCREASE QUICKLY AS AN APPROACHING SYSTEM BRINGS PRESSURE
FALLS OF 1 MB/HR. THE WEDNESDAY AFTERNOON HIGH TIDE IN BOSTON IS
11.7 FT AND STRONG SOUTHEASTERLY WINDS WILL BE JUST OFFSHORE.
RIGHT NOW BELIEVE MINOR COASTAL FLOODING IS POSSIBLE ALONG THE
EAST COAST.

WEDNESDAY EVENING...SOUTHERLY WINDS ARE EXPECTED AND ASTRONOMICAL
TIDES INCREASE ALONG THE SOUTH COAST. HIGH TIDE IN PROVIDENCE WILL
BE 5.2 FT. 925 MB LLJ STRENGTHENS TO 55-65 KTS WHICH COULD PUSH A
DECENT SURGE UP ALONG THE SOUTH COAST DURING THE TIME OF HIGH
TIDE. THINKING THAT MINOR COASTAL FLOODING COULD OCCUR BUT CANNOT
RULE OUT MODERATE ALONG THE SOUTH COAST...ESPECIALLY IF LLJ
CONTINUES TO STRENGTHEN.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 7 AM EST
     TUESDAY FOR ANZ250.
     SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 7 AM EST
     TUESDAY FOR ANZ251-255.
     SMALL CRAFT ADVISORY FROM 1 PM THIS AFTERNOON TO 7 AM EST
     TUESDAY FOR ANZ254.

&&

$$
SYNOPSIS...WTB/DUNTEN
NEAR TERM...DUNTEN
SHORT TERM...DUNTEN
LONG TERM...WTB
AVIATION...WTB/DUNTEN
MARINE...WTB/DUNTEN
TIDES/COASTAL FLOODING...




000
FXUS61 KBOX 220258
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
958 PM EST SUN DEC 21 2014

.SYNOPSIS...
SCATTERED SNOW/RAIN SHOWERS CONTINUE THROUGH MONDAY. WEAK LOW
PRESSURE WILL PASS SOUTH OF NEW ENGLAND BRINGING ANOTHER PERIOD OF
PRECIPITATION MONDAY NIGHT AND TUESDAY. A MUCH STRONGER STORM
PASSING WEST OF NEW ENGLAND WILL BRING HEAVY RAINFALL... GUSTY
WINDS AND COASTAL FLOODING CONCERNS TO THE REGION WEDNESDAY AND
WEDNESDAY NIGHT. DRY BUT VERY WINDY CONDITIONS FOLLOW FOR
CHRISTMAS DAY. HIGH PRESSURE BRINGS DRY WEATHER FRIDAY. ANOTHER
DEVELOPING SYSTEM MAY BRING RAIN AND SNOW NEXT SUNDAY.

&&

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

1000 PM UPDATE...

LATEST RADAR IMAGERY SHOWS LIGHT RADAR ECHOES ACROSS PORTIONS OF
SOUTHERN NEW ENGLAND...ESP SOUTH OF THE PIKE. DUE TO MOIST ONSHORE
FLOW FOR THE REMINDER OF THE NIGHT BELIEVE FLURRIES/LIGHT SNOW
SHOWERS WILL CONTINUE. NOT MUCH ACCUMULATION IS ANTICIPATED.
TEMPERATURES AT OR NEAR FREEZING COMBINED WITH HIGHER DEWPOINTS
MAY LEAD TO A FEW SLICK SPOTS OVERNIGHT INTO TOMORROW MORNING.
DRIVERS ARE URGED TO USE CAUTION.

PREVIOUS DISCUSSION...
SHORTWAVE RIDGING BUILDS OVER SOUTHERN NEW ENGLAND OVERNIGHT. IN
ADDITION...HIGH PRESSURE IN QUEBEC BUILDS OVER THE REGION AS WELL.
THEREFORE...THERE WILL BE NO FOCUSING MECHANISM FOR PRECIP.
HOWEVER...ONSHORE FLOW AND DECENT MID LEVEL LAPSE RATES WILL ALLOW
FOR A FEW SCATTERED SNOW/RAIN SHOWERS ACROSS THE AREA OVERNIGHT.
EXPECT SNOW SHOWERS TO REMAIN ROUGHLY NORTH AND WEST OF A NEWPORT
TO TAUNTON TO SCITUATE LINE. ANY ADDITIONAL SNOWFALL WILL AMOUNT
TO A DUSTING TO ABOUT AN INCH. TEMPERATURES WILL FALL INTO THE MID
20S ACROSS THE NORTHWEST TO THE MID 30S ON THE CAPE AND ISLANDS.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
MONDAY...CLOUDY...DAMP...AND RAW CONDITIONS WILL CONTINUE THROUGH
THE DAY WITH CONTINUED ONSHORE FLOW AND SCATTERED SNOW/RAIN SHOWERS.

MONDAY NIGHT...WEAK LOW PRESSURE MOVING UP THE COAST TO JUST OFF THE
DELMARVA PENINSULA WILL PRODUCE WARM ADVECTION OVER SOUTHERN NEW
ENGLAND.  THIS IN TURN WILL LIKELY RESULT IN SOME PRECIPITATION
DEVELOPING OVERNIGHT.  HIGH PRESSURE MOVING INTO THE MARITIMES WILL
ALLOW FOR SOME COLD AIR DAMMING...PARTICULARLY INTO INTERIOR
SOUTHERN NEW ENGLAND.  THIS SCENARIO IS A GOOD SET UP FOR SOME
FREEZING RAIN ACROSS THE INTERIOR.  THE MAIN QUESTION IS HOW FAR
NORTH THE WARMER AIR GETS AS THIS WILL DETERMINE PTYPE.  FOR
NOW...WILL MAKE MENTION OF THE POTENTIAL FOR AN AREA OF FREEZING
RAIN IN THE HAZARDOUS WEATHER OUTLOOK. IF FREEZING RAIN LOOKS TO BE
MORE CERTAIN...WE WILL NEED TO ISSUE A WINTER WEATHER ADVISORY.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
BIG PICTURE...

TUESDAY STARTS WITH UPPER RIDGES ON EACH COAST AND A DEEP UPPER
TROUGH/CLOSED LOW OVER THE PLAINS. BY WEDNESDAY THE CLOSED LOW
EJECTS NORTHEAST THROUGH LAKE SUPERIOR INTO CANADA. THIS SWEEPS THE
TROUGH AXIS EAST AND PASSES ACROSS NEW ENGLAND CHRISTMAS DAY.
ANOTHER SHORTWAVE MOVES ONSHORE IN THE PACIFIC NORTHWEST WEDNESDAY
AND PHASES WITH A SECOND DROPPING SOUTH FROM NORTHERN CANADA.  THIS
REESTABLISHES THE UPPER TROUGH OVER THE NORTHERN PLAINS/GREAT LAKES
SATURDAY.

CONTOUR HEIGHTS WILL BE ABOVE NORMAL MIDWEEK...TRENDING BELOW NORMAL
OVER THE WEEKEND AS THE SECOND UPPER TROUGH SHIFTS EAST. THIS POINTS
TO A COOLING TREND AFTER CHRISTMAS.

THE GFS AND ECMWF ARE SIMILAR IN HANDLING THE HOLIDAY STORM. THERE
ARE DIFFERENCES BETWEEN THE MODELS IN HANDLING THE SUNDAY SYSTEM. WE
USED A BLEND MOST OF THE LONG TERM PERIOD...BUT MANUALLY ADJUSTED
POPS FOR SUNDAY WITH LOW CONFIDENCE IN MODEL VALUES.

THE DAILIES...

TUESDAY... HIGH PRESSURE OVER THE MARITIMES WITH RIDGING DOWN THE
ATLANTIC COAST. COASTAL LOW PRESSURE WAVE DEVELOPS ALONG STALLED
WARM FRONT AND MOVES NORTH.  AS THE COASTAL LOW MOVES NORTH IT WILL
RUN UP AGAINST THE MARITIME HIGH. THIS WILL INCREASE THE LOW LEVEL
PRESSURE GRADIENT AND INCREASE THE LOW LEVEL SOUTHEAST WINDS.
RESULT...A SOUTHEAST LOW LEVEL JET RUNS OVER THE RIDGING ALONG THE
COASTAL PLAIN INDUCING LOW LEVEL LIFT. THE MOIST LAYER EXPANDS ABOVE
800 MB...NOT DEEP BUT DEEP ENOUGH FOR THE LIFT TO GENERATE LIGHT
PCPN. PTYPE WILL BE RAIN MOST PLACES...BUT THERE COULD BE SPOTS OF
LIGHT FREEZING RAIN IN NORTHWEST MASSACHUSETTS. WE WILL MAINTAIN
CHANCE POPS BUT INCREASE TO AROUND 50 PCT...THE HIGH END OF THE
CHANCE RANGE.

LOW LEVEL SOUTH JET MOVES UP THE COAST TUESDAY NIGHT REACHING THE
COOLER AIR OVER NEW ENGLAND AFTER MIDNIGHT AND BEFORE SUNRISE. THIS
WILL GENERATE ADDITIONAL LIFT AS WELL AS INCREASING AND DEEPENING
MOISTURE. THIS SUGGESTS INCREASING POPS OVERNIGHT.  TEMPERATURES
SHOULD REMAIN ABOVE FREEZING SO PTYPE SHOULD BE RAIN.

WEDNESDAY-THURSDAY... SOUTH 40-50 KNOT LOW LEVEL JET MOVES OVER NEW
ENGLAND WEDNESDAY GENERATING STRONG LIFT AND TRANSPORTING HIGH
VALUES OF PRECIPITABLE WATER INTO THAT LIFT. THE MOISTURE VALUES ARE
MORE THAN 3 STD DEVIATIONS ABOVE NORMAL FOR DECEMBER...AND ACTUALLY
NEAR THE MAXIMUM PREVIOUSLY OBSERVED VALUE. THIS SUGGESTS RAIN WITH
SOME HEAVY DOWNPOURS. COLD FRONT APPROACHES LATE WEDNESDAY NIGHT AND
CROSSES SOUTHERN NEW ENGLAND CHRISTMAS MORNING. THE FRONT WILL HAVE
DYNAMIC SUPPORT FROM A 140-150 KNOT UPPER JET. THE FOREWARD PROGRESS
OF THE FRONT WILL SLOW BECAUSE MOST OF THE MOTION IN THE UPPER JET
WILL BE PARALLEL TO THE FRONT. THIS WILL MEAN CONTINUED RAIN/HEAVY
RAIN THROUGH THE NIGHT INTO THURSDAY MORNING.

THE OBVIOUS CONCERN FOR THIS PERIOD WILL BE FLOODING FROM HEAVY
RAINFALL. RAIN AMOUNTS OF 2 TO 3 INCHES ARE EXPECTED. THIS SHOULD BE
SUFFICIENT FOR AT LEAST URBAN AND POOR DRAINAGE FLOODING. A FLOOD
WATCH MAY BE NEEDED.

A SECOND CONCERN WILL BE WIND. THE LOW LEVEL JET WEDNESDAY WILL BE
SOUTH 40-50 KNOTS...AND INCREASE TO 55-65 KNOTS WEDNESDAY NIGHT.
CONVENTIONAL MIXING WILL NOT BE DEEP...BUT HEAVY DOWNPOURS COULD
CREATE A MOIST ADIABATIC CHANNEL THAT BRINGS DOWN SOME STRONGER WIND
GUSTS. MODEL GRIDS ARE RATHER LIGHT ON WIND GUSTS...15 TO 30 KNOTS.
WE WILL MANUALLY ADJUST THESE VALUES UP TO 25-35 KNOTS OVER LAND AND
A LITTLE STRONGER OVER WATER.

A THIRD CONCERN WILL BE COASTAL FLOODING. MORE DETAILS ON THIS IN
THE TIDE/COASTAL FLOOD SECTION.

WINDS SHIFT TO WEST BEHIND THE FRONT ON CHRISTMAS DAY. THIS WILL
BRING DRIER AIR AND SO END THE RAINFALL. COLD ADVECTION WILL PROMOTE
MIXING TO NEAR 850 MB IN THE AFTERNOON AND TAP 25-35 KNOT WIND
GUSTS...POSSIBLY 40 KNOT GUSTS. A WIND ADVISORY MAY BE NEEDED FOR
THESE WEST WINDS THURSDAY.

FRIDAY THROUGH SUNDAY.... HIGH PRESSURE MOVES OVER THE REGION FRIDAY
BRINGING DRY WEATHER.  SHORTWAVE MOVING THROUGH THE GREAT LAKES
SWINGS A COLD FRONT THROUGH NEW ENGLAND SATURDAY. THE SURFACE
REFLECTION OF THE SHORTWAVE MOVES UP THE ST LAWRENCE VALLEY AND JET
SUPPPORT WILL MOSTLY BE NORTH OF THE BORDER...SO PCPN WILL BE
LIMITED.  QUESTION FOR SUNDAY WILL BE WHETHER A WAVE FORMS ON THE
DEPARTING COLD FRONT...IF SO IT MIGHT BRING PCPN TO NEW ENGLAND. THE
ECMWF THINKS SO BUT THE GFS DOES NOT. WE BROUGHT IN A CHANCE OF RAIN
AND SNOW SHOWERS.

&&

.AVIATION /03Z MONDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /THROUGH MONDAY NIGHT/...

TONIGHT...MODERATE CONFIDENCE. MAINLY MVFR CONDITIONS THROUGH
TONIGHT. ONE EXCEPTION IS OVER BOSTON AND ESSEX COUNTY WHERE THE
1500 FOOT CEILING BROKE TO 6500 FEET AND MAY STAY LIKE THAT
THROUGH THE EARLY NIGHT. BUT WITH CONTINUED ONSHORE FLOW AND A FEW
RAIN/SNOW SHOWERS UPSTREAM IT IS POSSIBLE CIGS WILL DROP BACK TO
1500 FEET IN ANY SHOWERS. THE OVERALL MOIST FLOW SHOULD ALSO BRING
LEVELS BACK TO MVFR OVERNIGHT. SECOND EXCEPTION IS OVER CAPE COD AND
THE ISLANDS WHERE VFR CONDITIONS CONTINUE IN PLACE. BELIEVE THESE
CONDITIONS WILL ALSO DETERIORATE OVERNIGHT IN THE ONSHORE
NORTHEAST FLOW.

MONDAY AND MONDAY NIGHT...MODERATE CONFIDENCE. MAINLY MVFR
CONDITIONS CONTINUE IN SCATTERED LIGHT SNOW SHOWERS. LIGHT FZRA
POSSIBLE LATE MONDAY NIGHT ACROSS NW MASSACHUSETTS.

KBOS TERMINAL...MODERATE CONFIDENCE.

KBDL TERMINAL...MODERATE CONFIDENCE.

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

TUESDAY...MVFR CIGS AND VSBYS IN LIGHT RAIN.  EAST SOUTHEAST
WINDS...WITH FREQUENT GUSTS TO 25 KNOTS ON THE CAPE AND ISLANDS.

LATE TUESDAY NIGHT-WEDNESDAY-THURSDAY... CONDITIONS LOWERING TO
IFR/LIFR IN RAIN/HEAVY RAIN. SOUTHEAST WINDS GUSTING 25 TO 35 KNOTS
WEDNESDAY AND SOUTH WINDS SIMILAR SPEEDS WEDNESDAY NIGHT...EXCEPT 30
TO 40 KNOTS CAPE COD AND ISLANDS. WINDS AT 2000 FEET MAY REACH 55 TO
65 KNOTS BY WEDNESDAY NIGHT CREATING LOW LEVEL WIND SHEAR. ISOLATED
THUNDERSTORMS WEDNESDAY AFTERNOON AND NIGHT. COLD FRONT SWINGS
THROUGH ON THURSDAY MORNING BRINGING A WIND SHIFT TO WEST WITH GUSTS
30-40 KNOTS.  CONDITIONS IMPROVE TO VFR AFTER THE WIND SHIFT.

FRIDAY...VFR.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

HIGH PRESSURE ACROSS QUEBEC AND THE MARITIMES WILL RESULT IN
PERSISTENT NORTHEASTERLY TO EASTERLY WINDS ACROSS THE WATERS THROUGH
MONDAY.  THIS WILL RESULT IN BUILDING SEAS ON THE EASTERN WATERS
DESPITE WIND GUSTS UP TO 20 KNOTS.  SEAS BUILD TO AT LEAST 5 FEET ON
THE EASTERN WATERS BY MIDDAY MONDAY. A SMALL CRAFT ADVISORY
CONTINUES FOR THE EASTERN WATERS FOR THE PERIOD FROM MIDDAY
MONDAY THROUGH TUESDAY MORNING. WINDS INCREASE TO NEAR 25 KTS ON
THE SOUTHERN WATERS BY 12Z TUESDAY.

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

TUESDAY...EAST WIND GUSTING TO 25 KNOTS...BECOMING SOUTHEAST AT
NIGHT. SEAS 5 TO 7 FEET ON THE EXPOSED WATERS.  A SMALL CRAFT
ADVISORY WILL BE NEEDED.

WEDNESDAY-THURSDAY... SOUTH WINDS WITH FREQUENT GUSTS 35 TO 40 KNOTS
BY WEDNESDAY AFTERNOON AND CONTINUING THROUGH THE NIGHT. WINDS SHIFT
WEST THURSDAY MORNING WITH SIMILAR SPEEDS THROUGH THE AFTERNOON.
SEAS WILL BUILD TO 7 TO 12 FEET ON THE EXPOSED WATERS BY WEDNESDAY
NIGHT AND THURSDAY.  A GALE WARNING MAY BE NEEDED.

FRIDAY...WINDS DIMINISHING TO 25 KNOTS FRIDAY MORNING AND BELOW 25
KNOTS BY AFTERNOON.  SEAS LINGERING AT 5 TO 7 FEET ON THE EXPOSED
WATERS. A SMALL CRAFT ADVISORY MAY BE NEEDED.

&&

.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES WILL OCCUR TUESDAY THROUGH THURSDAY.

TUESDAY...HIGH TIDE AT BOSTON WILL BE 11.6 FT. WINDS WILL BE FROM
THE EAST...SO THERE WILL BE ONSHORE FLOW DURING THIS HIGH TIDE
ALLOWING FOR MINOR SPLASHOVER. IF WINDS INCREASE THEN COULD SEE
SOME POCKETS OF MINOR COASTAL FLOODING.

WEDNESDAY...WINDS SHIFT TO A MORE SOUTHEASTERLY FLOW DURING THE DAY
AND INCREASE QUICKLY AS AN APPROACHING SYSTEM BRINGS PRESSURE
FALLS OF 1 MB/HR. THE WEDNESDAY AFTERNOON HIGH TIDE IN BOSTON IS
11.7 FT AND STRONG SOUTHEASTERLY WINDS WILL BE JUST OFFSHORE.
RIGHT NOW BELIEVE MINOR COASTAL FLOODING IS POSSIBLE ALONG THE
EAST COAST.

WEDNESDAY EVENING...SOUTHERLY WINDS ARE EXPECTED AND ASTRONOMICAL
TIDES INCREASE ALONG THE SOUTH COAST. HIGH TIDE IN PROVIDENCE WILL
BE 5.2 FT. 925 MB LLJ STRENGTHENS TO 55-65 KTS WHICH COULD PUSH A
DECENT SURGE UP ALONG THE SOUTH COAST DURING THE TIME OF HIGH
TIDE. THINKING THAT MINOR COASTAL FLOODING COULD OCCUR BUT CANNOT
RULE OUT MODERATE ALONG THE SOUTH COAST...ESPECIALLY IF LLJ
CONTINUES TO STRENGTHEN.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 4 PM MONDAY TO 7 AM EST TUESDAY FOR
     ANZ250.
     SMALL CRAFT ADVISORY FROM 10 PM MONDAY TO 7 AM EST TUESDAY FOR
     ANZ251-255.
     SMALL CRAFT ADVISORY FROM 1 PM MONDAY TO 7 AM EST TUESDAY FOR
     ANZ254.

&&

$$
SYNOPSIS...WTB/RLG
NEAR TERM...DUNTEN/RLG
SHORT TERM...RLG
LONG TERM...WTB
AVIATION...WTB/RLG
MARINE...WTB/RLG
TIDES/COASTAL FLOODING...




000
FXUS61 KBOX 220258
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
958 PM EST SUN DEC 21 2014

.SYNOPSIS...
SCATTERED SNOW/RAIN SHOWERS CONTINUE THROUGH MONDAY. WEAK LOW
PRESSURE WILL PASS SOUTH OF NEW ENGLAND BRINGING ANOTHER PERIOD OF
PRECIPITATION MONDAY NIGHT AND TUESDAY. A MUCH STRONGER STORM
PASSING WEST OF NEW ENGLAND WILL BRING HEAVY RAINFALL... GUSTY
WINDS AND COASTAL FLOODING CONCERNS TO THE REGION WEDNESDAY AND
WEDNESDAY NIGHT. DRY BUT VERY WINDY CONDITIONS FOLLOW FOR
CHRISTMAS DAY. HIGH PRESSURE BRINGS DRY WEATHER FRIDAY. ANOTHER
DEVELOPING SYSTEM MAY BRING RAIN AND SNOW NEXT SUNDAY.

&&

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

1000 PM UPDATE...

LATEST RADAR IMAGERY SHOWS LIGHT RADAR ECHOES ACROSS PORTIONS OF
SOUTHERN NEW ENGLAND...ESP SOUTH OF THE PIKE. DUE TO MOIST ONSHORE
FLOW FOR THE REMINDER OF THE NIGHT BELIEVE FLURRIES/LIGHT SNOW
SHOWERS WILL CONTINUE. NOT MUCH ACCUMULATION IS ANTICIPATED.
TEMPERATURES AT OR NEAR FREEZING COMBINED WITH HIGHER DEWPOINTS
MAY LEAD TO A FEW SLICK SPOTS OVERNIGHT INTO TOMORROW MORNING.
DRIVERS ARE URGED TO USE CAUTION.

PREVIOUS DISCUSSION...
SHORTWAVE RIDGING BUILDS OVER SOUTHERN NEW ENGLAND OVERNIGHT. IN
ADDITION...HIGH PRESSURE IN QUEBEC BUILDS OVER THE REGION AS WELL.
THEREFORE...THERE WILL BE NO FOCUSING MECHANISM FOR PRECIP.
HOWEVER...ONSHORE FLOW AND DECENT MID LEVEL LAPSE RATES WILL ALLOW
FOR A FEW SCATTERED SNOW/RAIN SHOWERS ACROSS THE AREA OVERNIGHT.
EXPECT SNOW SHOWERS TO REMAIN ROUGHLY NORTH AND WEST OF A NEWPORT
TO TAUNTON TO SCITUATE LINE. ANY ADDITIONAL SNOWFALL WILL AMOUNT
TO A DUSTING TO ABOUT AN INCH. TEMPERATURES WILL FALL INTO THE MID
20S ACROSS THE NORTHWEST TO THE MID 30S ON THE CAPE AND ISLANDS.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
MONDAY...CLOUDY...DAMP...AND RAW CONDITIONS WILL CONTINUE THROUGH
THE DAY WITH CONTINUED ONSHORE FLOW AND SCATTERED SNOW/RAIN SHOWERS.

MONDAY NIGHT...WEAK LOW PRESSURE MOVING UP THE COAST TO JUST OFF THE
DELMARVA PENINSULA WILL PRODUCE WARM ADVECTION OVER SOUTHERN NEW
ENGLAND.  THIS IN TURN WILL LIKELY RESULT IN SOME PRECIPITATION
DEVELOPING OVERNIGHT.  HIGH PRESSURE MOVING INTO THE MARITIMES WILL
ALLOW FOR SOME COLD AIR DAMMING...PARTICULARLY INTO INTERIOR
SOUTHERN NEW ENGLAND.  THIS SCENARIO IS A GOOD SET UP FOR SOME
FREEZING RAIN ACROSS THE INTERIOR.  THE MAIN QUESTION IS HOW FAR
NORTH THE WARMER AIR GETS AS THIS WILL DETERMINE PTYPE.  FOR
NOW...WILL MAKE MENTION OF THE POTENTIAL FOR AN AREA OF FREEZING
RAIN IN THE HAZARDOUS WEATHER OUTLOOK. IF FREEZING RAIN LOOKS TO BE
MORE CERTAIN...WE WILL NEED TO ISSUE A WINTER WEATHER ADVISORY.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
BIG PICTURE...

TUESDAY STARTS WITH UPPER RIDGES ON EACH COAST AND A DEEP UPPER
TROUGH/CLOSED LOW OVER THE PLAINS. BY WEDNESDAY THE CLOSED LOW
EJECTS NORTHEAST THROUGH LAKE SUPERIOR INTO CANADA. THIS SWEEPS THE
TROUGH AXIS EAST AND PASSES ACROSS NEW ENGLAND CHRISTMAS DAY.
ANOTHER SHORTWAVE MOVES ONSHORE IN THE PACIFIC NORTHWEST WEDNESDAY
AND PHASES WITH A SECOND DROPPING SOUTH FROM NORTHERN CANADA.  THIS
REESTABLISHES THE UPPER TROUGH OVER THE NORTHERN PLAINS/GREAT LAKES
SATURDAY.

CONTOUR HEIGHTS WILL BE ABOVE NORMAL MIDWEEK...TRENDING BELOW NORMAL
OVER THE WEEKEND AS THE SECOND UPPER TROUGH SHIFTS EAST. THIS POINTS
TO A COOLING TREND AFTER CHRISTMAS.

THE GFS AND ECMWF ARE SIMILAR IN HANDLING THE HOLIDAY STORM. THERE
ARE DIFFERENCES BETWEEN THE MODELS IN HANDLING THE SUNDAY SYSTEM. WE
USED A BLEND MOST OF THE LONG TERM PERIOD...BUT MANUALLY ADJUSTED
POPS FOR SUNDAY WITH LOW CONFIDENCE IN MODEL VALUES.

THE DAILIES...

TUESDAY... HIGH PRESSURE OVER THE MARITIMES WITH RIDGING DOWN THE
ATLANTIC COAST. COASTAL LOW PRESSURE WAVE DEVELOPS ALONG STALLED
WARM FRONT AND MOVES NORTH.  AS THE COASTAL LOW MOVES NORTH IT WILL
RUN UP AGAINST THE MARITIME HIGH. THIS WILL INCREASE THE LOW LEVEL
PRESSURE GRADIENT AND INCREASE THE LOW LEVEL SOUTHEAST WINDS.
RESULT...A SOUTHEAST LOW LEVEL JET RUNS OVER THE RIDGING ALONG THE
COASTAL PLAIN INDUCING LOW LEVEL LIFT. THE MOIST LAYER EXPANDS ABOVE
800 MB...NOT DEEP BUT DEEP ENOUGH FOR THE LIFT TO GENERATE LIGHT
PCPN. PTYPE WILL BE RAIN MOST PLACES...BUT THERE COULD BE SPOTS OF
LIGHT FREEZING RAIN IN NORTHWEST MASSACHUSETTS. WE WILL MAINTAIN
CHANCE POPS BUT INCREASE TO AROUND 50 PCT...THE HIGH END OF THE
CHANCE RANGE.

LOW LEVEL SOUTH JET MOVES UP THE COAST TUESDAY NIGHT REACHING THE
COOLER AIR OVER NEW ENGLAND AFTER MIDNIGHT AND BEFORE SUNRISE. THIS
WILL GENERATE ADDITIONAL LIFT AS WELL AS INCREASING AND DEEPENING
MOISTURE. THIS SUGGESTS INCREASING POPS OVERNIGHT.  TEMPERATURES
SHOULD REMAIN ABOVE FREEZING SO PTYPE SHOULD BE RAIN.

WEDNESDAY-THURSDAY... SOUTH 40-50 KNOT LOW LEVEL JET MOVES OVER NEW
ENGLAND WEDNESDAY GENERATING STRONG LIFT AND TRANSPORTING HIGH
VALUES OF PRECIPITABLE WATER INTO THAT LIFT. THE MOISTURE VALUES ARE
MORE THAN 3 STD DEVIATIONS ABOVE NORMAL FOR DECEMBER...AND ACTUALLY
NEAR THE MAXIMUM PREVIOUSLY OBSERVED VALUE. THIS SUGGESTS RAIN WITH
SOME HEAVY DOWNPOURS. COLD FRONT APPROACHES LATE WEDNESDAY NIGHT AND
CROSSES SOUTHERN NEW ENGLAND CHRISTMAS MORNING. THE FRONT WILL HAVE
DYNAMIC SUPPORT FROM A 140-150 KNOT UPPER JET. THE FOREWARD PROGRESS
OF THE FRONT WILL SLOW BECAUSE MOST OF THE MOTION IN THE UPPER JET
WILL BE PARALLEL TO THE FRONT. THIS WILL MEAN CONTINUED RAIN/HEAVY
RAIN THROUGH THE NIGHT INTO THURSDAY MORNING.

THE OBVIOUS CONCERN FOR THIS PERIOD WILL BE FLOODING FROM HEAVY
RAINFALL. RAIN AMOUNTS OF 2 TO 3 INCHES ARE EXPECTED. THIS SHOULD BE
SUFFICIENT FOR AT LEAST URBAN AND POOR DRAINAGE FLOODING. A FLOOD
WATCH MAY BE NEEDED.

A SECOND CONCERN WILL BE WIND. THE LOW LEVEL JET WEDNESDAY WILL BE
SOUTH 40-50 KNOTS...AND INCREASE TO 55-65 KNOTS WEDNESDAY NIGHT.
CONVENTIONAL MIXING WILL NOT BE DEEP...BUT HEAVY DOWNPOURS COULD
CREATE A MOIST ADIABATIC CHANNEL THAT BRINGS DOWN SOME STRONGER WIND
GUSTS. MODEL GRIDS ARE RATHER LIGHT ON WIND GUSTS...15 TO 30 KNOTS.
WE WILL MANUALLY ADJUST THESE VALUES UP TO 25-35 KNOTS OVER LAND AND
A LITTLE STRONGER OVER WATER.

A THIRD CONCERN WILL BE COASTAL FLOODING. MORE DETAILS ON THIS IN
THE TIDE/COASTAL FLOOD SECTION.

WINDS SHIFT TO WEST BEHIND THE FRONT ON CHRISTMAS DAY. THIS WILL
BRING DRIER AIR AND SO END THE RAINFALL. COLD ADVECTION WILL PROMOTE
MIXING TO NEAR 850 MB IN THE AFTERNOON AND TAP 25-35 KNOT WIND
GUSTS...POSSIBLY 40 KNOT GUSTS. A WIND ADVISORY MAY BE NEEDED FOR
THESE WEST WINDS THURSDAY.

FRIDAY THROUGH SUNDAY.... HIGH PRESSURE MOVES OVER THE REGION FRIDAY
BRINGING DRY WEATHER.  SHORTWAVE MOVING THROUGH THE GREAT LAKES
SWINGS A COLD FRONT THROUGH NEW ENGLAND SATURDAY. THE SURFACE
REFLECTION OF THE SHORTWAVE MOVES UP THE ST LAWRENCE VALLEY AND JET
SUPPPORT WILL MOSTLY BE NORTH OF THE BORDER...SO PCPN WILL BE
LIMITED.  QUESTION FOR SUNDAY WILL BE WHETHER A WAVE FORMS ON THE
DEPARTING COLD FRONT...IF SO IT MIGHT BRING PCPN TO NEW ENGLAND. THE
ECMWF THINKS SO BUT THE GFS DOES NOT. WE BROUGHT IN A CHANCE OF RAIN
AND SNOW SHOWERS.

&&

.AVIATION /03Z MONDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /THROUGH MONDAY NIGHT/...

TONIGHT...MODERATE CONFIDENCE. MAINLY MVFR CONDITIONS THROUGH
TONIGHT. ONE EXCEPTION IS OVER BOSTON AND ESSEX COUNTY WHERE THE
1500 FOOT CEILING BROKE TO 6500 FEET AND MAY STAY LIKE THAT
THROUGH THE EARLY NIGHT. BUT WITH CONTINUED ONSHORE FLOW AND A FEW
RAIN/SNOW SHOWERS UPSTREAM IT IS POSSIBLE CIGS WILL DROP BACK TO
1500 FEET IN ANY SHOWERS. THE OVERALL MOIST FLOW SHOULD ALSO BRING
LEVELS BACK TO MVFR OVERNIGHT. SECOND EXCEPTION IS OVER CAPE COD AND
THE ISLANDS WHERE VFR CONDITIONS CONTINUE IN PLACE. BELIEVE THESE
CONDITIONS WILL ALSO DETERIORATE OVERNIGHT IN THE ONSHORE
NORTHEAST FLOW.

MONDAY AND MONDAY NIGHT...MODERATE CONFIDENCE. MAINLY MVFR
CONDITIONS CONTINUE IN SCATTERED LIGHT SNOW SHOWERS. LIGHT FZRA
POSSIBLE LATE MONDAY NIGHT ACROSS NW MASSACHUSETTS.

KBOS TERMINAL...MODERATE CONFIDENCE.

KBDL TERMINAL...MODERATE CONFIDENCE.

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

TUESDAY...MVFR CIGS AND VSBYS IN LIGHT RAIN.  EAST SOUTHEAST
WINDS...WITH FREQUENT GUSTS TO 25 KNOTS ON THE CAPE AND ISLANDS.

LATE TUESDAY NIGHT-WEDNESDAY-THURSDAY... CONDITIONS LOWERING TO
IFR/LIFR IN RAIN/HEAVY RAIN. SOUTHEAST WINDS GUSTING 25 TO 35 KNOTS
WEDNESDAY AND SOUTH WINDS SIMILAR SPEEDS WEDNESDAY NIGHT...EXCEPT 30
TO 40 KNOTS CAPE COD AND ISLANDS. WINDS AT 2000 FEET MAY REACH 55 TO
65 KNOTS BY WEDNESDAY NIGHT CREATING LOW LEVEL WIND SHEAR. ISOLATED
THUNDERSTORMS WEDNESDAY AFTERNOON AND NIGHT. COLD FRONT SWINGS
THROUGH ON THURSDAY MORNING BRINGING A WIND SHIFT TO WEST WITH GUSTS
30-40 KNOTS.  CONDITIONS IMPROVE TO VFR AFTER THE WIND SHIFT.

FRIDAY...VFR.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

HIGH PRESSURE ACROSS QUEBEC AND THE MARITIMES WILL RESULT IN
PERSISTENT NORTHEASTERLY TO EASTERLY WINDS ACROSS THE WATERS THROUGH
MONDAY.  THIS WILL RESULT IN BUILDING SEAS ON THE EASTERN WATERS
DESPITE WIND GUSTS UP TO 20 KNOTS.  SEAS BUILD TO AT LEAST 5 FEET ON
THE EASTERN WATERS BY MIDDAY MONDAY. A SMALL CRAFT ADVISORY
CONTINUES FOR THE EASTERN WATERS FOR THE PERIOD FROM MIDDAY
MONDAY THROUGH TUESDAY MORNING. WINDS INCREASE TO NEAR 25 KTS ON
THE SOUTHERN WATERS BY 12Z TUESDAY.

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

TUESDAY...EAST WIND GUSTING TO 25 KNOTS...BECOMING SOUTHEAST AT
NIGHT. SEAS 5 TO 7 FEET ON THE EXPOSED WATERS.  A SMALL CRAFT
ADVISORY WILL BE NEEDED.

WEDNESDAY-THURSDAY... SOUTH WINDS WITH FREQUENT GUSTS 35 TO 40 KNOTS
BY WEDNESDAY AFTERNOON AND CONTINUING THROUGH THE NIGHT. WINDS SHIFT
WEST THURSDAY MORNING WITH SIMILAR SPEEDS THROUGH THE AFTERNOON.
SEAS WILL BUILD TO 7 TO 12 FEET ON THE EXPOSED WATERS BY WEDNESDAY
NIGHT AND THURSDAY.  A GALE WARNING MAY BE NEEDED.

FRIDAY...WINDS DIMINISHING TO 25 KNOTS FRIDAY MORNING AND BELOW 25
KNOTS BY AFTERNOON.  SEAS LINGERING AT 5 TO 7 FEET ON THE EXPOSED
WATERS. A SMALL CRAFT ADVISORY MAY BE NEEDED.

&&

.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES WILL OCCUR TUESDAY THROUGH THURSDAY.

TUESDAY...HIGH TIDE AT BOSTON WILL BE 11.6 FT. WINDS WILL BE FROM
THE EAST...SO THERE WILL BE ONSHORE FLOW DURING THIS HIGH TIDE
ALLOWING FOR MINOR SPLASHOVER. IF WINDS INCREASE THEN COULD SEE
SOME POCKETS OF MINOR COASTAL FLOODING.

WEDNESDAY...WINDS SHIFT TO A MORE SOUTHEASTERLY FLOW DURING THE DAY
AND INCREASE QUICKLY AS AN APPROACHING SYSTEM BRINGS PRESSURE
FALLS OF 1 MB/HR. THE WEDNESDAY AFTERNOON HIGH TIDE IN BOSTON IS
11.7 FT AND STRONG SOUTHEASTERLY WINDS WILL BE JUST OFFSHORE.
RIGHT NOW BELIEVE MINOR COASTAL FLOODING IS POSSIBLE ALONG THE
EAST COAST.

WEDNESDAY EVENING...SOUTHERLY WINDS ARE EXPECTED AND ASTRONOMICAL
TIDES INCREASE ALONG THE SOUTH COAST. HIGH TIDE IN PROVIDENCE WILL
BE 5.2 FT. 925 MB LLJ STRENGTHENS TO 55-65 KTS WHICH COULD PUSH A
DECENT SURGE UP ALONG THE SOUTH COAST DURING THE TIME OF HIGH
TIDE. THINKING THAT MINOR COASTAL FLOODING COULD OCCUR BUT CANNOT
RULE OUT MODERATE ALONG THE SOUTH COAST...ESPECIALLY IF LLJ
CONTINUES TO STRENGTHEN.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 4 PM MONDAY TO 7 AM EST TUESDAY FOR
     ANZ250.
     SMALL CRAFT ADVISORY FROM 10 PM MONDAY TO 7 AM EST TUESDAY FOR
     ANZ251-255.
     SMALL CRAFT ADVISORY FROM 1 PM MONDAY TO 7 AM EST TUESDAY FOR
     ANZ254.

&&

$$
SYNOPSIS...WTB/RLG
NEAR TERM...DUNTEN/RLG
SHORT TERM...RLG
LONG TERM...WTB
AVIATION...WTB/RLG
MARINE...WTB/RLG
TIDES/COASTAL FLOODING...





000
FXUS61 KBOX 212347
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
647 PM EST SUN DEC 21 2014

.SYNOPSIS...
SCATTERED SNOW/RAIN SHOWERS CONTINUE THROUGH MONDAY. WEAK LOW
PRESSURE WILL PASS SOUTH OF NEW ENGLAND BRINGING ANOTHER PERIOD OF
PRECIPITATION MONDAY NIGHT AND TUESDAY. A MUCH STRONGER STORM
PASSING WEST OF NEW ENGLAND WILL BRING HEAVY RAINFALL... GUSTY
WINDS AND COASTAL FLOODING CONCERNS TO THE REGION WEDNESDAY AND
WEDNESDAY NIGHT. DRY BUT VERY WINDY CONDITIONS FOLLOW FOR
CHRISTMAS DAY. HIGH PRESSURE BRINGS DRY WEATHER FRIDAY. ANOTHER
DEVELOPING SYSTEM MAY BRING RAIN AND SNOW NEXT SUNDAY.

&&

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

645 PM UPDATE...
TWO AREAS OF LIGHT RAIN/SNOW SHOWERS ON RADAR...ONE MOVING
SOUTHWEST FROM THE GULF OF MAINE TOWARD SOUTHEAST MASS AND THE
OTHER MOVING NORTH ONTO THE SOUTH COASTS OF RI AND MASS. WE
ADJUSTED POPS TO REFLECT THE CHANCES BEING IN AREAS MAINLY SOUTH
OF THE MASS PIKE EARLY TONIGHT. AS NOTED EARLIER...THE LIGHT PCPN
SHOULD AMOUNT TO SNOW ACCUMULATIONS OF A DUSTING/COATING UP TO
POSSIBLY AN INCH IN A FEW PLACES. NO OTHER CHANGES TO THE EXISTING
FORECAST.

PREVIOUS DISCUSSION...
SHORTWAVE RIDGING BUILDS OVER SOUTHERN NEW ENGLAND OVERNIGHT. IN
ADDITION...HIGH PRESSURE IN QUEBEC BUILDS OVER THE REGION AS WELL.
THEREFORE...THERE WILL BE NO FOCUSING MECHANISM FOR PRECIP.
HOWEVER...ONSHORE FLOW AND DECENT MID LEVEL LAPSE RATES WILL ALLOW
FOR A FEW SCATTERED SNOW/RAIN SHOWERS ACROSS THE AREA OVERNIGHT.
EXPECT SNOW SHOWERS TO REMAIN ROUGHLY NORTH AND WEST OF A NEWPORT
TO TAUNTON TO SCITUATE LINE. ANY ADDITIONAL SNOWFALL WILL AMOUNT
TO A DUSTING TO ABOUT AN INCH. TEMPERATURES WILL FALL INTO THE MID
20S ACROSS THE NORTHWEST TO THE MID 30S ON THE CAPE AND ISLANDS.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
MONDAY...CLOUDY...DAMP...AND RAW CONDITIONS WILL CONTINUE THROUGH
THE DAY WITH CONTINUED ONSHORE FLOW AND SCATTERED SNOW/RAIN SHOWERS.

MONDAY NIGHT...WEAK LOW PRESSURE MOVING UP THE COAST TO JUST OFF THE
DELMARVA PENINSULA WILL PRODUCE WARM ADVECTION OVER SOUTHERN NEW
ENGLAND.  THIS IN TURN WILL LIKELY RESULT IN SOME PRECIPITATION
DEVELOPING OVERNIGHT.  HIGH PRESSURE MOVING INTO THE MARITIMES WILL
ALLOW FOR SOME COLD AIR DAMMING...PARTICULARLY INTO INTERIOR
SOUTHERN NEW ENGLAND.  THIS SCENARIO IS A GOOD SET UP FOR SOME
FREEZING RAIN ACROSS THE INTERIOR.  THE MAIN QUESTION IS HOW FAR
NORTH THE WARMER AIR GETS AS THIS WILL DETERMINE PTYPE.  FOR
NOW...WILL MAKE MENTION OF THE POTENTIAL FOR AN AREA OF FREEZING
RAIN IN THE HAZARDOUS WEATHER OUTLOOK. IF FREEZING RAIN LOOKS TO BE
MORE CERTAIN...WE WILL NEED TO ISSUE A WINTER WEATHER ADVISORY.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
BIG PICTURE...

TUESDAY STARTS WITH UPPER RIDGES ON EACH COAST AND A DEEP UPPER
TROUGH/CLOSED LOW OVER THE PLAINS. BY WEDNESDAY THE CLOSED LOW
EJECTS NORTHEAST THROUGH LAKE SUPERIOR INTO CANADA. THIS SWEEPS THE
TROUGH AXIS EAST AND PASSES ACROSS NEW ENGLAND CHRISTMAS DAY.
ANOTHER SHORTWAVE MOVES ONSHORE IN THE PACIFIC NORTHWEST WEDNESDAY
AND PHASES WITH A SECOND DROPPING SOUTH FROM NORTHERN CANADA.  THIS
REESTABLISHES THE UPPER TROUGH OVER THE NORTHERN PLAINS/GREAT LAKES
SATURDAY.

CONTOUR HEIGHTS WILL BE ABOVE NORMAL MIDWEEK...TRENDING BELOW NORMAL
OVER THE WEEKEND AS THE SECOND UPPER TROUGH SHIFTS EAST. THIS POINTS
TO A COOLING TREND AFTER CHRISTMAS.

THE GFS AND ECMWF ARE SIMILAR IN HANDLING THE HOLIDAY STORM. THERE
ARE DIFFERENCES BETWEEN THE MODELS IN HANDLING THE SUNDAY SYSTEM. WE
USED A BLEND MOST OF THE LONG TERM PERIOD...BUT MANUALLY ADJUSTED
POPS FOR SUNDAY WITH LOW CONFIDENCE IN MODEL VALUES.

THE DAILIES...

TUESDAY... HIGH PRESSURE OVER THE MARITIMES WITH RIDGING DOWN THE
ATLANTIC COAST. COASTAL LOW PRESSURE WAVE DEVELOPS ALONG STALLED
WARM FRONT AND MOVES NORTH.  AS THE COASTAL LOW MOVES NORTH IT WILL
RUN UP AGAINST THE MARITIME HIGH. THIS WILL INCREASE THE LOW LEVEL
PRESSURE GRADIENT AND INCREASE THE LOW LEVEL SOUTHEAST WINDS.
RESULT...A SOUTHEAST LOW LEVEL JET RUNS OVER THE RIDGING ALONG THE
COASTAL PLAIN INDUCING LOW LEVEL LIFT. THE MOIST LAYER EXPANDS ABOVE
800 MB...NOT DEEP BUT DEEP ENOUGH FOR THE LIFT TO GENERATE LIGHT
PCPN. PTYPE WILL BE RAIN MOST PLACES...BUT THERE COULD BE SPOTS OF
LIGHT FREEZING RAIN IN NORTHWEST MASSACHUSETTS. WE WILL MAINTAIN
CHANCE POPS BUT INCREASE TO AROUND 50 PCT...THE HIGH END OF THE
CHANCE RANGE.

LOW LEVEL SOUTH JET MOVES UP THE COAST TUESDAY NIGHT REACHING THE
COOLER AIR OVER NEW ENGLAND AFTER MIDNIGHT AND BEFORE SUNRISE. THIS
WILL GENERATE ADDITIONAL LIFT AS WELL AS INCREASING AND DEEPENING
MOISTURE. THIS SUGGESTS INCREASING POPS OVERNIGHT.  TEMPERATURES
SHOULD REMAIN ABOVE FREEZING SO PTYPE SHOULD BE RAIN.

WEDNESDAY-THURSDAY... SOUTH 40-50 KNOT LOW LEVEL JET MOVES OVER NEW
ENGLAND WEDNESDAY GENERATING STRONG LIFT AND TRANSPORTING HIGH
VALUES OF PRECIPITABLE WATER INTO THAT LIFT. THE MOISTURE VALUES ARE
MORE THAN 3 STD DEVIATIONS ABOVE NORMAL FOR DECEMBER...AND ACTUALLY
NEAR THE MAXIMUM PREVIOUSLY OBSERVED VALUE. THIS SUGGESTS RAIN WITH
SOME HEAVY DOWNPOURS. COLD FRONT APPROACHES LATE WEDNESDAY NIGHT AND
CROSSES SOUTHERN NEW ENGLAND CHRISTMAS MORNING. THE FRONT WILL HAVE
DYNAMIC SUPPORT FROM A 140-150 KNOT UPPER JET. THE FOREWARD PROGRESS
OF THE FRONT WILL SLOW BECAUSE MOST OF THE MOTION IN THE UPPER JET
WILL BE PARALLEL TO THE FRONT. THIS WILL MEAN CONTINUED RAIN/HEAVY
RAIN THROUGH THE NIGHT INTO THURSDAY MORNING.

THE OBVIOUS CONCERN FOR THIS PERIOD WILL BE FLOODING FROM HEAVY
RAINFALL. RAIN AMOUNTS OF 2 TO 3 INCHES ARE EXPECTED. THIS SHOULD BE
SUFFICIENT FOR AT LEAST URBAN AND POOR DRAINAGE FLOODING. A FLOOD
WATCH MAY BE NEEDED.

A SECOND CONCERN WILL BE WIND. THE LOW LEVEL JET WEDNESDAY WILL BE
SOUTH 40-50 KNOTS...AND INCREASE TO 55-65 KNOTS WEDNESDAY NIGHT.
CONVENTIONAL MIXING WILL NOT BE DEEP...BUT HEAVY DOWNPOURS COULD
CREATE A MOIST ADIABATIC CHANNEL THAT BRINGS DOWN SOME STRONGER WIND
GUSTS. MODEL GRIDS ARE RATHER LIGHT ON WIND GUSTS...15 TO 30 KNOTS.
WE WILL MANUALLY ADJUST THESE VALUES UP TO 25-35 KNOTS OVER LAND AND
A LITTLE STRONGER OVER WATER.

A THIRD CONCERN WILL BE COASTAL FLOODING. MORE DETAILS ON THIS IN
THE TIDE/COASTAL FLOOD SECTION.

WINDS SHIFT TO WEST BEHIND THE FRONT ON CHRISTMAS DAY. THIS WILL
BRING DRIER AIR AND SO END THE RAINFALL. COLD ADVECTION WILL PROMOTE
MIXING TO NEAR 850 MB IN THE AFTERNOON AND TAP 25-35 KNOT WIND
GUSTS...POSSIBLY 40 KNOT GUSTS. A WIND ADVISORY MAY BE NEEDED FOR
THESE WEST WINDS THURSDAY.

FRIDAY THROUGH SUNDAY.... HIGH PRESSURE MOVES OVER THE REGION FRIDAY
BRINGING DRY WEATHER.  SHORTWAVE MOVING THROUGH THE GREAT LAKES
SWINGS A COLD FRONT THROUGH NEW ENGLAND SATURDAY. THE SURFACE
REFLECTION OF THE SHORTWAVE MOVES UP THE ST LAWRENCE VALLEY AND JET
SUPPPORT WILL MOSTLY BE NORTH OF THE BORDER...SO PCPN WILL BE
LIMITED.  QUESTION FOR SUNDAY WILL BE WHETHER A WAVE FORMS ON THE
DEPARTING COLD FRONT...IF SO IT MIGHT BRING PCPN TO NEW ENGLAND. THE
ECMWF THINKS SO BUT THE GFS DOES NOT. WE BROUGHT IN A CHANCE OF RAIN
AND SNOW SHOWERS.

&&

.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 /THROUGH MONDAY NIGHT/...

TONIGHT...MODERATE CONFIDENCE. MAINLY MVFR CONDITIONS THROUGH
TONIGHT. ONE EXCEPTION IS OVER BOSTON AND ESSEX COUNTY WHERE THE
1500 FOOT CEILING BROKE TO 6500 FEET AND MAY STAY LIKE THAT
THROUGH THE EARLY NIGHT. BUT WITH CONTINUED ONSHORE FLOW AND A FEW
RAIN/SNOW SHOWERS UPSTREAM IT IS POSSIBLE CIGS WILL DROP BACK TO
1500 FEET IN ANY SHOWERS. THE OVERALL MOIST FLOW SHOULD ALSO BRING
LEVELS BACK TO MVFR OVERNIGHT. SECOND EXCEPTION IS OVER CAPE COD AND
THE ISLANDS WHERE VFR CONDITIONS CONTINUE IN PLACE. BELIEVE THESE
CONDITIONS WILL ALSO DETERIORATE OVERNIGHT IN THE ONSHORE
NORTHEAST FLOW.

MONDAY AND MONDAY NIGHT...MODERATE CONFIDENCE. MAINLY MVFR
CONDITIONS CONTINUE IN SCATTERED LIGHT SNOW SHOWERS. LIGHT FZRA
POSSIBLE LATE MONDAY NIGHT ACROSS NW MASSACHUSETTS.

KBOS TERMINAL...MODERATE CONFIDENCE.

KBDL TERMINAL...MODERATE CONFIDENCE.

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

TUESDAY...MVFR CIGS AND VSBYS IN LIGHT RAIN.  EAST SOUTHEAST
WINDS...WITH FREQUENT GUSTS TO 25 KNOTS ON THE CAPE AND ISLANDS.

LATE TUESDAY NIGHT-WEDNESDAY-THURSDAY... CONDITIONS LOWERING TO
IFR/LIFR IN RAIN/HEAVY RAIN. SOUTHEAST WINDS GUSTING 25 TO 35 KNOTS
WEDNESDAY AND SOUTH WINDS SIMILAR SPEEDS WEDNESDAY NIGHT...EXCEPT 30
TO 40 KNOTS CAPE COD AND ISLANDS. WINDS AT 2000 FEET MAY REACH 55 TO
65 KNOTS BY WEDNESDAY NIGHT CREATING LOW LEVEL WIND SHEAR. ISOLATED
THUNDERSTORMS WEDNESDAY AFTERNOON AND NIGHT. COLD FRONT SWINGS
THROUGH ON THURSDAY MORNING BRINGING A WIND SHIFT TO WEST WITH GUSTS
30-40 KNOTS.  CONDITIONS IMPROVE TO VFR AFTER THE WIND SHIFT.

FRIDAY...VFR.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

HIGH PRESSURE ACROSS QUEBEC AND THE MARITIMES WILL RESULT IN
PERSISTENT NORTHEASTERLY TO EASTERLY WINDS ACROSS THE WATERS THROUGH
MONDAY.  THIS WILL RESULT IN BUILDING SEAS ON THE EASTERN WATERS
DESPITE WIND GUSTS UP TO 20 KNOTS.  SEAS BUILD TO AT LEAST 5 FEET ON
THE EASTERN WATERS BY MIDDAY MONDAY. A SMALL CRAFT ADVISORY
CONTINUES FOR THE EASTERN WATERS FOR THE PERIOD FROM MIDDAY
MONDAY THROUGH TUESDAY MORNING. WINDS INCREASE TO NEAR 25 KTS ON
THE SOUTHERN WATERS BY 12Z TUESDAY.

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

TUESDAY...EAST WIND GUSTING TO 25 KNOTS...BECOMING SOUTHEAST AT
NIGHT. SEAS 5 TO 7 FEET ON THE EXPOSED WATERS.  A SMALL CRAFT
ADVISORY WILL BE NEEDED.

WEDNESDAY-THURSDAY... SOUTH WINDS WITH FREQUENT GUSTS 35 TO 40 KNOTS
BY WEDNESDAY AFTERNOON AND CONTINUING THROUGH THE NIGHT. WINDS SHIFT
WEST THURSDAY MORNING WITH SIMILAR SPEEDS THROUGH THE AFTERNOON.
SEAS WILL BUILD TO 7 TO 12 FEET ON THE EXPOSED WATERS BY WEDNESDAY
NIGHT AND THURSDAY.  A GALE WARNING MAY BE NEEDED.

FRIDAY...WINDS DIMINISHING TO 25 KNOTS FRIDAY MORNING AND BELOW 25
KNOTS BY AFTERNOON.  SEAS LINGERING AT 5 TO 7 FEET ON THE EXPOSED
WATERS. A SMALL CRAFT ADVISORY MAY BE NEEDED.

&&

.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES WILL OCCUR TUESDAY THROUGH THURSDAY.

TUESDAY...HIGH TIDE AT BOSTON WILL BE 11.6 FT. WINDS WILL BE FROM
THE EAST...SO THERE WILL BE ONSHORE FLOW DURING THIS HIGH TIDE
ALLOWING FOR MINOR SPLASHOVER. IF WINDS INCREASE THEN COULD SEE
SOME POCKETS OF MINOR COASTAL FLOODING.

WEDNESDAY...WINDS SHIFT TO A MORE SOUTHEASTERLY FLOW DURING THE DAY
AND INCREASE QUICKLY AS AN APPROACHING SYSTEM BRINGS PRESSURE
FALLS OF 1 MB/HR. THE WEDNESDAY AFTERNOON HIGH TIDE IN BOSTON IS
11.7 FT AND STRONG SOUTHEASTERLY WINDS WILL BE JUST OFFSHORE.
RIGHT NOW BELIEVE MINOR COASTAL FLOODING IS POSSIBLE ALONG THE
EAST COAST.

WEDNESDAY EVENING...SOUTHERLY WINDS ARE EXPECTED AND ASTRONOMICAL
TIDES INCREASE ALONG THE SOUTH COAST. HIGH TIDE IN PROVIDENCE WILL
BE 5.2 FT. 925 MB LLJ STRENGTHENS TO 55-65 KTS WHICH COULD PUSH A
DECENT SURGE UP ALONG THE SOUTH COAST DURING THE TIME OF HIGH
TIDE. THINKING THAT MINOR COASTAL FLOODING COULD OCCUR BUT CANNOT
RULE OUT MODERATE ALONG THE SOUTH COAST...ESPECIALLY IF LLJ
CONTINUES TO STRENGTHEN.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 4 PM MONDAY TO 7 AM EST TUESDAY FOR
     ANZ250.
     SMALL CRAFT ADVISORY FROM 10 PM MONDAY TO 7 AM EST TUESDAY FOR
     ANZ251-255.
     SMALL CRAFT ADVISORY FROM 1 PM MONDAY TO 7 AM EST TUESDAY FOR
     ANZ254.

&&

$$
SYNOPSIS...WTB/RLG
NEAR TERM...WTB/RLG
SHORT TERM...RLG
LONG TERM...WTB
AVIATION...WTB/RLG
MARINE...WTB/RLG
TIDES/COASTAL FLOODING...RLG




000
FXUS61 KBOX 212347
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
647 PM EST SUN DEC 21 2014

.SYNOPSIS...
SCATTERED SNOW/RAIN SHOWERS CONTINUE THROUGH MONDAY. WEAK LOW
PRESSURE WILL PASS SOUTH OF NEW ENGLAND BRINGING ANOTHER PERIOD OF
PRECIPITATION MONDAY NIGHT AND TUESDAY. A MUCH STRONGER STORM
PASSING WEST OF NEW ENGLAND WILL BRING HEAVY RAINFALL... GUSTY
WINDS AND COASTAL FLOODING CONCERNS TO THE REGION WEDNESDAY AND
WEDNESDAY NIGHT. DRY BUT VERY WINDY CONDITIONS FOLLOW FOR
CHRISTMAS DAY. HIGH PRESSURE BRINGS DRY WEATHER FRIDAY. ANOTHER
DEVELOPING SYSTEM MAY BRING RAIN AND SNOW NEXT SUNDAY.

&&

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

645 PM UPDATE...
TWO AREAS OF LIGHT RAIN/SNOW SHOWERS ON RADAR...ONE MOVING
SOUTHWEST FROM THE GULF OF MAINE TOWARD SOUTHEAST MASS AND THE
OTHER MOVING NORTH ONTO THE SOUTH COASTS OF RI AND MASS. WE
ADJUSTED POPS TO REFLECT THE CHANCES BEING IN AREAS MAINLY SOUTH
OF THE MASS PIKE EARLY TONIGHT. AS NOTED EARLIER...THE LIGHT PCPN
SHOULD AMOUNT TO SNOW ACCUMULATIONS OF A DUSTING/COATING UP TO
POSSIBLY AN INCH IN A FEW PLACES. NO OTHER CHANGES TO THE EXISTING
FORECAST.

PREVIOUS DISCUSSION...
SHORTWAVE RIDGING BUILDS OVER SOUTHERN NEW ENGLAND OVERNIGHT. IN
ADDITION...HIGH PRESSURE IN QUEBEC BUILDS OVER THE REGION AS WELL.
THEREFORE...THERE WILL BE NO FOCUSING MECHANISM FOR PRECIP.
HOWEVER...ONSHORE FLOW AND DECENT MID LEVEL LAPSE RATES WILL ALLOW
FOR A FEW SCATTERED SNOW/RAIN SHOWERS ACROSS THE AREA OVERNIGHT.
EXPECT SNOW SHOWERS TO REMAIN ROUGHLY NORTH AND WEST OF A NEWPORT
TO TAUNTON TO SCITUATE LINE. ANY ADDITIONAL SNOWFALL WILL AMOUNT
TO A DUSTING TO ABOUT AN INCH. TEMPERATURES WILL FALL INTO THE MID
20S ACROSS THE NORTHWEST TO THE MID 30S ON THE CAPE AND ISLANDS.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
MONDAY...CLOUDY...DAMP...AND RAW CONDITIONS WILL CONTINUE THROUGH
THE DAY WITH CONTINUED ONSHORE FLOW AND SCATTERED SNOW/RAIN SHOWERS.

MONDAY NIGHT...WEAK LOW PRESSURE MOVING UP THE COAST TO JUST OFF THE
DELMARVA PENINSULA WILL PRODUCE WARM ADVECTION OVER SOUTHERN NEW
ENGLAND.  THIS IN TURN WILL LIKELY RESULT IN SOME PRECIPITATION
DEVELOPING OVERNIGHT.  HIGH PRESSURE MOVING INTO THE MARITIMES WILL
ALLOW FOR SOME COLD AIR DAMMING...PARTICULARLY INTO INTERIOR
SOUTHERN NEW ENGLAND.  THIS SCENARIO IS A GOOD SET UP FOR SOME
FREEZING RAIN ACROSS THE INTERIOR.  THE MAIN QUESTION IS HOW FAR
NORTH THE WARMER AIR GETS AS THIS WILL DETERMINE PTYPE.  FOR
NOW...WILL MAKE MENTION OF THE POTENTIAL FOR AN AREA OF FREEZING
RAIN IN THE HAZARDOUS WEATHER OUTLOOK. IF FREEZING RAIN LOOKS TO BE
MORE CERTAIN...WE WILL NEED TO ISSUE A WINTER WEATHER ADVISORY.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
BIG PICTURE...

TUESDAY STARTS WITH UPPER RIDGES ON EACH COAST AND A DEEP UPPER
TROUGH/CLOSED LOW OVER THE PLAINS. BY WEDNESDAY THE CLOSED LOW
EJECTS NORTHEAST THROUGH LAKE SUPERIOR INTO CANADA. THIS SWEEPS THE
TROUGH AXIS EAST AND PASSES ACROSS NEW ENGLAND CHRISTMAS DAY.
ANOTHER SHORTWAVE MOVES ONSHORE IN THE PACIFIC NORTHWEST WEDNESDAY
AND PHASES WITH A SECOND DROPPING SOUTH FROM NORTHERN CANADA.  THIS
REESTABLISHES THE UPPER TROUGH OVER THE NORTHERN PLAINS/GREAT LAKES
SATURDAY.

CONTOUR HEIGHTS WILL BE ABOVE NORMAL MIDWEEK...TRENDING BELOW NORMAL
OVER THE WEEKEND AS THE SECOND UPPER TROUGH SHIFTS EAST. THIS POINTS
TO A COOLING TREND AFTER CHRISTMAS.

THE GFS AND ECMWF ARE SIMILAR IN HANDLING THE HOLIDAY STORM. THERE
ARE DIFFERENCES BETWEEN THE MODELS IN HANDLING THE SUNDAY SYSTEM. WE
USED A BLEND MOST OF THE LONG TERM PERIOD...BUT MANUALLY ADJUSTED
POPS FOR SUNDAY WITH LOW CONFIDENCE IN MODEL VALUES.

THE DAILIES...

TUESDAY... HIGH PRESSURE OVER THE MARITIMES WITH RIDGING DOWN THE
ATLANTIC COAST. COASTAL LOW PRESSURE WAVE DEVELOPS ALONG STALLED
WARM FRONT AND MOVES NORTH.  AS THE COASTAL LOW MOVES NORTH IT WILL
RUN UP AGAINST THE MARITIME HIGH. THIS WILL INCREASE THE LOW LEVEL
PRESSURE GRADIENT AND INCREASE THE LOW LEVEL SOUTHEAST WINDS.
RESULT...A SOUTHEAST LOW LEVEL JET RUNS OVER THE RIDGING ALONG THE
COASTAL PLAIN INDUCING LOW LEVEL LIFT. THE MOIST LAYER EXPANDS ABOVE
800 MB...NOT DEEP BUT DEEP ENOUGH FOR THE LIFT TO GENERATE LIGHT
PCPN. PTYPE WILL BE RAIN MOST PLACES...BUT THERE COULD BE SPOTS OF
LIGHT FREEZING RAIN IN NORTHWEST MASSACHUSETTS. WE WILL MAINTAIN
CHANCE POPS BUT INCREASE TO AROUND 50 PCT...THE HIGH END OF THE
CHANCE RANGE.

LOW LEVEL SOUTH JET MOVES UP THE COAST TUESDAY NIGHT REACHING THE
COOLER AIR OVER NEW ENGLAND AFTER MIDNIGHT AND BEFORE SUNRISE. THIS
WILL GENERATE ADDITIONAL LIFT AS WELL AS INCREASING AND DEEPENING
MOISTURE. THIS SUGGESTS INCREASING POPS OVERNIGHT.  TEMPERATURES
SHOULD REMAIN ABOVE FREEZING SO PTYPE SHOULD BE RAIN.

WEDNESDAY-THURSDAY... SOUTH 40-50 KNOT LOW LEVEL JET MOVES OVER NEW
ENGLAND WEDNESDAY GENERATING STRONG LIFT AND TRANSPORTING HIGH
VALUES OF PRECIPITABLE WATER INTO THAT LIFT. THE MOISTURE VALUES ARE
MORE THAN 3 STD DEVIATIONS ABOVE NORMAL FOR DECEMBER...AND ACTUALLY
NEAR THE MAXIMUM PREVIOUSLY OBSERVED VALUE. THIS SUGGESTS RAIN WITH
SOME HEAVY DOWNPOURS. COLD FRONT APPROACHES LATE WEDNESDAY NIGHT AND
CROSSES SOUTHERN NEW ENGLAND CHRISTMAS MORNING. THE FRONT WILL HAVE
DYNAMIC SUPPORT FROM A 140-150 KNOT UPPER JET. THE FOREWARD PROGRESS
OF THE FRONT WILL SLOW BECAUSE MOST OF THE MOTION IN THE UPPER JET
WILL BE PARALLEL TO THE FRONT. THIS WILL MEAN CONTINUED RAIN/HEAVY
RAIN THROUGH THE NIGHT INTO THURSDAY MORNING.

THE OBVIOUS CONCERN FOR THIS PERIOD WILL BE FLOODING FROM HEAVY
RAINFALL. RAIN AMOUNTS OF 2 TO 3 INCHES ARE EXPECTED. THIS SHOULD BE
SUFFICIENT FOR AT LEAST URBAN AND POOR DRAINAGE FLOODING. A FLOOD
WATCH MAY BE NEEDED.

A SECOND CONCERN WILL BE WIND. THE LOW LEVEL JET WEDNESDAY WILL BE
SOUTH 40-50 KNOTS...AND INCREASE TO 55-65 KNOTS WEDNESDAY NIGHT.
CONVENTIONAL MIXING WILL NOT BE DEEP...BUT HEAVY DOWNPOURS COULD
CREATE A MOIST ADIABATIC CHANNEL THAT BRINGS DOWN SOME STRONGER WIND
GUSTS. MODEL GRIDS ARE RATHER LIGHT ON WIND GUSTS...15 TO 30 KNOTS.
WE WILL MANUALLY ADJUST THESE VALUES UP TO 25-35 KNOTS OVER LAND AND
A LITTLE STRONGER OVER WATER.

A THIRD CONCERN WILL BE COASTAL FLOODING. MORE DETAILS ON THIS IN
THE TIDE/COASTAL FLOOD SECTION.

WINDS SHIFT TO WEST BEHIND THE FRONT ON CHRISTMAS DAY. THIS WILL
BRING DRIER AIR AND SO END THE RAINFALL. COLD ADVECTION WILL PROMOTE
MIXING TO NEAR 850 MB IN THE AFTERNOON AND TAP 25-35 KNOT WIND
GUSTS...POSSIBLY 40 KNOT GUSTS. A WIND ADVISORY MAY BE NEEDED FOR
THESE WEST WINDS THURSDAY.

FRIDAY THROUGH SUNDAY.... HIGH PRESSURE MOVES OVER THE REGION FRIDAY
BRINGING DRY WEATHER.  SHORTWAVE MOVING THROUGH THE GREAT LAKES
SWINGS A COLD FRONT THROUGH NEW ENGLAND SATURDAY. THE SURFACE
REFLECTION OF THE SHORTWAVE MOVES UP THE ST LAWRENCE VALLEY AND JET
SUPPPORT WILL MOSTLY BE NORTH OF THE BORDER...SO PCPN WILL BE
LIMITED.  QUESTION FOR SUNDAY WILL BE WHETHER A WAVE FORMS ON THE
DEPARTING COLD FRONT...IF SO IT MIGHT BRING PCPN TO NEW ENGLAND. THE
ECMWF THINKS SO BUT THE GFS DOES NOT. WE BROUGHT IN A CHANCE OF RAIN
AND SNOW SHOWERS.

&&

.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 /THROUGH MONDAY NIGHT/...

TONIGHT...MODERATE CONFIDENCE. MAINLY MVFR CONDITIONS THROUGH
TONIGHT. ONE EXCEPTION IS OVER BOSTON AND ESSEX COUNTY WHERE THE
1500 FOOT CEILING BROKE TO 6500 FEET AND MAY STAY LIKE THAT
THROUGH THE EARLY NIGHT. BUT WITH CONTINUED ONSHORE FLOW AND A FEW
RAIN/SNOW SHOWERS UPSTREAM IT IS POSSIBLE CIGS WILL DROP BACK TO
1500 FEET IN ANY SHOWERS. THE OVERALL MOIST FLOW SHOULD ALSO BRING
LEVELS BACK TO MVFR OVERNIGHT. SECOND EXCEPTION IS OVER CAPE COD AND
THE ISLANDS WHERE VFR CONDITIONS CONTINUE IN PLACE. BELIEVE THESE
CONDITIONS WILL ALSO DETERIORATE OVERNIGHT IN THE ONSHORE
NORTHEAST FLOW.

MONDAY AND MONDAY NIGHT...MODERATE CONFIDENCE. MAINLY MVFR
CONDITIONS CONTINUE IN SCATTERED LIGHT SNOW SHOWERS. LIGHT FZRA
POSSIBLE LATE MONDAY NIGHT ACROSS NW MASSACHUSETTS.

KBOS TERMINAL...MODERATE CONFIDENCE.

KBDL TERMINAL...MODERATE CONFIDENCE.

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

TUESDAY...MVFR CIGS AND VSBYS IN LIGHT RAIN.  EAST SOUTHEAST
WINDS...WITH FREQUENT GUSTS TO 25 KNOTS ON THE CAPE AND ISLANDS.

LATE TUESDAY NIGHT-WEDNESDAY-THURSDAY... CONDITIONS LOWERING TO
IFR/LIFR IN RAIN/HEAVY RAIN. SOUTHEAST WINDS GUSTING 25 TO 35 KNOTS
WEDNESDAY AND SOUTH WINDS SIMILAR SPEEDS WEDNESDAY NIGHT...EXCEPT 30
TO 40 KNOTS CAPE COD AND ISLANDS. WINDS AT 2000 FEET MAY REACH 55 TO
65 KNOTS BY WEDNESDAY NIGHT CREATING LOW LEVEL WIND SHEAR. ISOLATED
THUNDERSTORMS WEDNESDAY AFTERNOON AND NIGHT. COLD FRONT SWINGS
THROUGH ON THURSDAY MORNING BRINGING A WIND SHIFT TO WEST WITH GUSTS
30-40 KNOTS.  CONDITIONS IMPROVE TO VFR AFTER THE WIND SHIFT.

FRIDAY...VFR.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

HIGH PRESSURE ACROSS QUEBEC AND THE MARITIMES WILL RESULT IN
PERSISTENT NORTHEASTERLY TO EASTERLY WINDS ACROSS THE WATERS THROUGH
MONDAY.  THIS WILL RESULT IN BUILDING SEAS ON THE EASTERN WATERS
DESPITE WIND GUSTS UP TO 20 KNOTS.  SEAS BUILD TO AT LEAST 5 FEET ON
THE EASTERN WATERS BY MIDDAY MONDAY. A SMALL CRAFT ADVISORY
CONTINUES FOR THE EASTERN WATERS FOR THE PERIOD FROM MIDDAY
MONDAY THROUGH TUESDAY MORNING. WINDS INCREASE TO NEAR 25 KTS ON
THE SOUTHERN WATERS BY 12Z TUESDAY.

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

TUESDAY...EAST WIND GUSTING TO 25 KNOTS...BECOMING SOUTHEAST AT
NIGHT. SEAS 5 TO 7 FEET ON THE EXPOSED WATERS.  A SMALL CRAFT
ADVISORY WILL BE NEEDED.

WEDNESDAY-THURSDAY... SOUTH WINDS WITH FREQUENT GUSTS 35 TO 40 KNOTS
BY WEDNESDAY AFTERNOON AND CONTINUING THROUGH THE NIGHT. WINDS SHIFT
WEST THURSDAY MORNING WITH SIMILAR SPEEDS THROUGH THE AFTERNOON.
SEAS WILL BUILD TO 7 TO 12 FEET ON THE EXPOSED WATERS BY WEDNESDAY
NIGHT AND THURSDAY.  A GALE WARNING MAY BE NEEDED.

FRIDAY...WINDS DIMINISHING TO 25 KNOTS FRIDAY MORNING AND BELOW 25
KNOTS BY AFTERNOON.  SEAS LINGERING AT 5 TO 7 FEET ON THE EXPOSED
WATERS. A SMALL CRAFT ADVISORY MAY BE NEEDED.

&&

.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES WILL OCCUR TUESDAY THROUGH THURSDAY.

TUESDAY...HIGH TIDE AT BOSTON WILL BE 11.6 FT. WINDS WILL BE FROM
THE EAST...SO THERE WILL BE ONSHORE FLOW DURING THIS HIGH TIDE
ALLOWING FOR MINOR SPLASHOVER. IF WINDS INCREASE THEN COULD SEE
SOME POCKETS OF MINOR COASTAL FLOODING.

WEDNESDAY...WINDS SHIFT TO A MORE SOUTHEASTERLY FLOW DURING THE DAY
AND INCREASE QUICKLY AS AN APPROACHING SYSTEM BRINGS PRESSURE
FALLS OF 1 MB/HR. THE WEDNESDAY AFTERNOON HIGH TIDE IN BOSTON IS
11.7 FT AND STRONG SOUTHEASTERLY WINDS WILL BE JUST OFFSHORE.
RIGHT NOW BELIEVE MINOR COASTAL FLOODING IS POSSIBLE ALONG THE
EAST COAST.

WEDNESDAY EVENING...SOUTHERLY WINDS ARE EXPECTED AND ASTRONOMICAL
TIDES INCREASE ALONG THE SOUTH COAST. HIGH TIDE IN PROVIDENCE WILL
BE 5.2 FT. 925 MB LLJ STRENGTHENS TO 55-65 KTS WHICH COULD PUSH A
DECENT SURGE UP ALONG THE SOUTH COAST DURING THE TIME OF HIGH
TIDE. THINKING THAT MINOR COASTAL FLOODING COULD OCCUR BUT CANNOT
RULE OUT MODERATE ALONG THE SOUTH COAST...ESPECIALLY IF LLJ
CONTINUES TO STRENGTHEN.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 4 PM MONDAY TO 7 AM EST TUESDAY FOR
     ANZ250.
     SMALL CRAFT ADVISORY FROM 10 PM MONDAY TO 7 AM EST TUESDAY FOR
     ANZ251-255.
     SMALL CRAFT ADVISORY FROM 1 PM MONDAY TO 7 AM EST TUESDAY FOR
     ANZ254.

&&

$$
SYNOPSIS...WTB/RLG
NEAR TERM...WTB/RLG
SHORT TERM...RLG
LONG TERM...WTB
AVIATION...WTB/RLG
MARINE...WTB/RLG
TIDES/COASTAL FLOODING...RLG





000
FXUS61 KBOX 212056
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
356 PM EST SUN DEC 21 2014

.SYNOPSIS...
SCATTERED SNOW/RAIN SHOWERS CONTINUE THROUGH MONDAY. WEAK LOW
PRESSURE WILL PASS SOUTH OF NEW ENGLAND BRINGING ANOTHER PERIOD OF
PRECIPITATION MONDAY NIGHT AND TUESDAY. A MUCH STRONGER STORM
PASSING WEST OF NEW ENGLAND WILL BRING HEAVY RAINFALL... GUSTY
WINDS AND COASTAL FLOODING CONCERNS TO THE REGION WEDNESDAY AND
WEDNESDAY NIGHT. DRY BUT VERY WINDY CONDITIONS FOLLOW FOR
CHRISTMAS DAY. HIGH PRESSURE BRINGS DRY WEATHER FRIDAY. ANOTHER
DEVELOPING SYSTEM MAY BRING RAIN AND SNOW NEXT SUNDAY.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
SHORTWAVE RIDGING BUILDS OVER SOUTHERN NEW ENGLAND OVERNIGHT. IN
ADDITION...HIGH PRESSURE IN QUEBEC BUILDS OVER THE REGION AS WELL.
THEREFORE...THERE WILL BE NO FOCUSING MECHANISM FOR PRECIP.
HOWEVER...ONSHORE FLOW AND DECENT MID LEVEL LAPSE RATES WILL ALLOW
FOR A FEW SCATTERED SNOW/RAIN SHOWERS ACROSS THE AREA OVERNIGHT.
EXPECT SNOW SHOWERS TO REMAIN ROUGHLY NORTH AND WEST OF A NEWPORT TO
TAUNTON TO SCITUATE LINE.  ANY ADDITIONAL SNOWFALL WILL AMOUNT TO A
DUSTING TO ABOUT AN INCH. TEMPERATURES WILL FALL INTO THE MID 20S
ACROSS THE NORTHWEST TO THE MID 30S ON THE CAPE AND ISLANDS.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
MONDAY...CLOUDY...DAMP...AND RAW CONDITIONS WILL CONTINUE THROUGH
THE DAY WITH CONTINUED ONSHORE FLOW AND SCATTERED SNOW/RAIN SHOWERS.

MONDAY NIGHT...WEAK LOW PRESSURE MOVING UP THE COAST TO JUST OFF THE
DELMARVA PENINSULA WILL PRODUCE WARM ADVECTION OVER SOUTHERN NEW
ENGLAND.  THIS IN TURN WILL LIKELY RESULT IN SOME PRECIPITATION
DEVELOPING OVERNIGHT.  HIGH PRESSURE MOVING INTO THE MARITIMES WILL
ALLOW FOR SOME COLD AIR DAMMING...PARTICULARLY INTO INTERIOR
SOUTHERN NEW ENGLAND.  THIS SCENARIO IS A GOOD SET UP FOR SOME
FREEZING RAIN ACROSS THE INTERIOR.  THE MAIN QUESTION IS HOW FAR
NORTH THE WARMER AIR GETS AS THIS WILL DETERMINE PTYPE.  FOR
NOW...WILL MAKE MENTION OF THE POTENTIAL FOR AN AREA OF FREEZING
RAIN IN THE HAZARDOUS WEATHER OUTLOOK. IF FREEZING RAIN LOOKS TO BE
MORE CERTAIN...WE WILL NEED TO ISSUE A WINTER WEATHER ADVISORY.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...

BIG PICTURE...

TUESDAY STARTS WITH UPPER RIDGES ON EACH COAST AND A DEEP UPPER
TROUGH/CLOSED LOW OVER THE PLAINS. BY WEDNESDAY THE CLOSED LOW
EJECTS NORTHEAST THROUGH LAKE SUPERIOR INTO CANADA. THIS SWEEPS THE
TROUGH AXIS EAST AND PASSES ACROSS NEW ENGLAND CHRISTMAS DAY.
ANOTHER SHORTWAVE MOVES ONSHORE IN THE PACIFIC NORTHWEST WEDNESDAY
AND PHASES WITH A SECOND DROPPING SOUTH FROM NORTHERN CANADA.  THIS
REESTABLISHES THE UPPER TROUGH OVER THE NORTHERN PLAINS/GREAT LAKES
SATURDAY.

CONTOUR HEIGHTS WILL BE ABOVE NORMAL MIDWEEK...TRENDING BELOW NORMAL
OVER THE WEEKEND AS THE SECOND UPPER TROUGH SHIFTS EAST. THIS POINTS
TO A COOLING TREND AFTER CHRISTMAS.

THE GFS AND ECMWF ARE SIMILAR IN HANDLING THE HOLIDAY STORM. THERE
ARE DIFFERENCES BETWEEN THE MODELS IN HANDLING THE SUNDAY SYSTEM. WE
USED A BLEND MOST OF THE LONG TERM PERIOD...BUT MANUALLY ADJUSTED
POPS FOR SUNDAY WITH LOW CONFIDENCE IN MODEL VALUES.

THE DAILIES...

TUESDAY... HIGH PRESSURE OVER THE MARITIMES WITH RIDGING DOWN THE
ATLANTIC COAST. COASTAL LOW PRESSURE WAVE DEVELOPS ALONG STALLED
WARM FRONT AND MOVES NORTH.  AS THE COASTAL LOW MOVES NORTH IT WILL
RUN UP AGAINST THE MARITIME HIGH. THIS WILL INCREASE THE LOW LEVEL
PRESSURE GRADIENT AND INCREASE THE LOW LEVEL SOUTHEAST WINDS.
RESULT...A SOUTHEAST LOW LEVEL JET RUNS OVER THE RIDGING ALONG THE
COASTAL PLAIN INDUCING LOW LEVEL LIFT. THE MOIST LAYER EXPANDS ABOVE
800 MB...NOT DEEP BUT DEEP ENOUGH FOR THE LIFT TO GENERATE LIGHT
PCPN. PTYPE WILL BE RAIN MOST PLACES...BUT THERE COULD BE SPOTS OF
LIGHT FREEZING RAIN IN NORTHWEST MASSACHUSETTS. WE WILL MAINTAIN
CHANCE POPS BUT INCREASE TO AROUND 50 PCT...THE HIGH END OF THE
CHANCE RANGE.

LOW LEVEL SOUTH JET MOVES UP THE COAST TUESDAY NIGHT REACHING THE
COOLER AIR OVER NEW ENGLAND AFTER MIDNIGHT AND BEFORE SUNRISE. THIS
WILL GENERATE ADDITIONAL LIFT AS WELL AS INCREASING AND DEEPENING
MOISTURE. THIS SUGGESTS INCREASING POPS OVERNIGHT.  TEMPERATURES
SHOULD REMAIN ABOVE FREEZING SO PTYPE SHOULD BE RAIN.

WEDNESDAY-THURSDAY... SOUTH 40-50 KNOT LOW LEVEL JET MOVES OVER NEW
ENGLAND WEDNESDAY GENERATING STRONG LIFT AND TRANSPORTING HIGH
VALUES OF PRECIPITABLE WATER INTO THAT LIFT. THE MOISTURE VALUES ARE
MORE THAN 3 STD DEVIATIONS ABOVE NORMAL FOR DECEMBER...AND ACTUALLY
NEAR THE MAXIMUM PREVIOUSLY OBSERVED VALUE. THIS SUGGESTS RAIN WITH
SOME HEAVY DOWNPOURS. COLD FRONT APPROACHES LATE WEDNESDAY NIGHT AND
CROSSES SOUTHERN NEW ENGLAND CHRISTMAS MORNING. THE FRONT WILL HAVE
DYNAMIC SUPPORT FROM A 140-150 KNOT UPPER JET. THE FOREWARD PROGRESS
OF THE FRONT WILL SLOW BECAUSE MOST OF THE MOTION IN THE UPPER JET
WILL BE PARALLEL TO THE FRONT. THIS WILL MEAN CONTINUED RAIN/HEAVY
RAIN THROUGH THE NIGHT INTO THURSDAY MORNING.

THE OBVIOUS CONCERN FOR THIS PERIOD WILL BE FLOODING FROM HEAVY
RAINFALL. RAIN AMOUNTS OF 2 TO 3 INCHES ARE EXPECTED. THIS SHOULD BE
SUFFICIENT FOR AT LEAST URBAN AND POOR DRAINAGE FLOODING. A FLOOD
WATCH MAY BE NEEDED.

A SECOND CONCERN WILL BE WIND. THE LOW LEVEL JET WEDNESDAY WILL BE
SOUTH 40-50 KNOTS...AND INCREASE TO 55-65 KNOTS WEDNESDAY NIGHT.
CONVENTIONAL MIXING WILL NOT BE DEEP...BUT HEAVY DOWNPOURS COULD
CREATE A MOIST ADIABATIC CHANNEL THAT BRINGS DOWN SOME STRONGER WIND
GUSTS. MODEL GRIDS ARE RATHER LIGHT ON WIND GUSTS...15 TO 30 KNOTS.
WE WILL MANUALLY ADJUST THESE VALUES UP TO 25-35 KNOTS OVER LAND AND
A LITTLE STRONGER OVER WATER.

A THIRD CONCERN WILL BE COASTAL FLOODING. MORE DETAILS ON THIS IN
THE TIDE/COASTAL FLOOD SECTION.

WINDS SHIFT TO WEST BEHIND THE FRONT ON CHRISTMAS DAY. THIS WILL
BRING DRIER AIR AND SO END THE RAINFALL. COLD ADVECTION WILL PROMOTE
MIXING TO NEAR 850 MB IN THE AFTERNOON AND TAP 25-35 KNOT WIND
GUSTS...POSSIBLY 40 KNOT GUSTS. A WIND ADVISORY MAY BE NEEDED FOR
THESE WEST WINDS THURSDAY.

FRIDAY THROUGH SUNDAY.... HIGH PRESSURE MOVES OVER THE REGION FRIDAY
BRINGING DRY WEATHER.  SHORTWAVE MOVING THROUGH THE GREAT LAKES
SWINGS A COLD FRONT THROUGH NEW ENGLAND SATURDAY. THE SURFACE
REFLECTION OF THE SHORTWAVE MOVES UP THE ST LAWRENCE VALLEY AND JET
SUPPPORT WILL MOSTLY BE NORTH OF THE BORDER...SO PCPN WILL BE
LIMITED.  QUESTION FOR SUNDAY WILL BE WHETHER A WAVE FORMS ON THE
DEPARTING COLD FRONT...IF SO IT MIGHT BRING PCPN TO NEW ENGLAND. THE
ECMWF THINKS SO BUT THE GFS DOES NOT. WE BROUGHT IN A CHANCE OF RAIN
AND SNOW SHOWERS.

&&

.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 /THROUGH MONDAY NIGHT/...

THROUGH TONIGHT...MODERATE CONFIDENCE. MAINLY MVFR/IFR CONDITIONS
THROUGH TONIGHT. EXCEPTION RIGHT NOW IS THE CAPE AND ISLANDS WHERE
VFR CONDITIONS ARE IN PLACE. BELIEVE CONDITIONS WILL DETERIORATE
LATER TONIGHT THERE. WIDESPREAD LIGHT SNOW SHOWERS ARE AFFECTING
ALL OF SOUTHERN NEW ENGLAND THIS AFTERNOON. EXPECT THIS ACTIVITY
TO BECOME MORE SCATTERED IN NATURE. RAIN SHOWERS ACROSS MOST OF
PLYMOUTH COUNTY AND ONTO THE CAPE/ISLANDS WITH SNOW SHOWERS NORTH
AND WEST.

MONDAY AND MONDAY NIGHT...MODERATE CONFIDENCE. MAINLY MVFR
CONDITIONS CONTINUE IN SCATTERED LIGHT SNOW SHOWERS. LIGHT FZRA
POSSIBLE LATE MONDAY NIGHT ACROSS NW MASSACHUSETTS.

KBOS TERMINAL...MODERATE CONFIDENCE.

KBDL TERMINAL...MODERATE CONFIDENCE.

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

TUESDAY...MVFR CIGS AND VSBYS IN LIGHT RAIN.  EAST SOUTHEAST
WINDS...WITH FREQUENT GUSTS TO 25 KNOTS ON THE CAPE AND ISLANDS.

LATE TUESDAY NIGHT-WEDNESDAY-THURSDAY... CONDITIONS LOWERING TO
IFR/LIFR IN RAIN/HEAVY RAIN. SOUTHEAST WINDS GUSTING 25 TO 35 KNOTS
WEDNESDAY AND SOUTH WINDS SIMILAR SPEEDS WEDNESDAY NIGHT...EXCEPT 30
TO 40 KNOTS CAPE COD AND ISLANDS. WINDS AT 2000 FEET MAY REACH 55 TO
65 KNOTS BY WEDNESDAY NIGHT CREATING LOW LEVEL WIND SHEAR. ISOLATED
THUNDERSTORMS WEDNESDAY AFTERNOON AND NIGHT. COLD FRONT SWINGS
THROUGH ON THURSDAY MORNING BRINGING A WIND SHIFT TO WEST WITH GUSTS
30-40 KNOTS.  CONDITIONS IMPROVE TO VFR AFTER THE WIND SHIFT.

FRIDAY...
VFR.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

HIGH PRESSURE ACROSS QUEBEC AND THE MARITIMES WILL RESULT IN
PERSISTENT NORTHEASTERLY TO EASTERLY WINDS ACROSS THE WATERS THROUGH
MONDAY.  THIS WILL RESULT IN BUILDING SEAS ON THE EASTERN WATERS
DESPITE WIND GUSTS UP TO 20 KNOTS.  SEAS BUILD TO AT LEAST 5 FEET ON
THE EASTERN WATERS BY MIDDAY MONDAY.  HAVE ISSUED A SMALL CRAFT
ADVISORY FOR THE EASTERN WATERS BEGINNING MIDDAY MONDAY AND
CONTINUING THROUGH TUESDAY MORNING.  WINDS INCREASE TO NEAR 25 KTS
ON THE SOUTHERN WATERS BY 12Z TUESDAY.

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

TUESDAY...EAST WIND GUSTING TO 25 KNOTS...BECOMING SOUTHEAST AT
NIGHT. SEAS 5 TO 7 FEET ON THE EXPOSED WATERS.  A SMALL CRAFT
ADVISORY WILL BE NEEDED.

WEDNESDAY-THURSDAY... SOUTH WINDS WITH FREQUENT GUSTS 35 TO 40 KNOTS
BY WEDNESDAY AFTERNOON AND CONTINUING THROUGH THE NIGHT. WINDS SHIFT
WEST THURSDAY MORNING WITH SIMILAR SPEEDS THROUGH THE AFTERNOON.
SEAS WILL BUILD TO 7 TO 12 FEET ON THE EXPOSED WATERS BY WEDNESDAY
NIGHT AND THURSDAY.  A GALE WARNING MAY BE NEEDED.

FRIDAY...WINDS DIMINISHING TO 25 KNOTS FRIDAY MORNING AND BELOW 25
KNOTS BY AFTERNOON.  SEAS LINGERING AT 5 TO 7 FEET ON THE EXPOSED
WATERS. A SMALL CRAFT ADVISORY MAY BE NEEDED.

&&

.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES WILL OCCUR TUESDAY THROUGH THURSDAY.

TUESDAY...HIGH TIDE AT BOSTON WILL BE 11.6 FT. WINDS WILL BE FROM
THE EAST...SO THERE WILL BE ONSHORE FLOW DURING THIS HIGH TIDE
ALLOWING FOR MINOR SPLASHOVER. IF WINDS INCREASE THEN COULD SEE
SOME POCKETS OF MINOR COASTAL FLOODING.

WEDNESDAY...WINDS SHIFT TO A MORE SOUTHEASTERLY FLOW DURING THE DAY
AND INCREASE QUICKLY AS AN APPROACHING SYSTEM BRINGS PRESSURE
FALLS OF 1 MB/HR. THE WEDNESDAY AFTERNOON HIGH TIDE IN BOSTON IS
11.7 FT AND STRONG SOUTHEASTERLY WINDS WILL BE JUST OFFSHORE.
RIGHT NOW BELIEVE MINOR COASTAL FLOODING IS POSSIBLE ALONG THE
EAST COAST.

WEDNESDAY EVENING...SOUTHERLY WINDS ARE EXPECTED AND ASTRONOMICAL
TIDES INCREASE ALONG THE SOUTH COAST. HIGH TIDE IN PROVIDENCE WILL
BE 5.2 FT. 925 MB LLJ STRENGTHENS TO 55-65 KTS WHICH COULD PUSH A
DECENT SURGE UP ALONG THE SOUTH COAST DURING THE TIME OF HIGH
TIDE. THINKING THAT MINOR COASTAL FLOODING COULD OCCUR BUT CANNOT
RULE OUT MODERATE ALONG THE SOUTH COAST...ESPECIALLY IF LLJ
CONTINUES TO STRENGTHEN.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 4 PM MONDAY TO 7 AM EST TUESDAY FOR
     ANZ250.
     SMALL CRAFT ADVISORY FROM 10 PM MONDAY TO 7 AM EST TUESDAY FOR
     ANZ251-255.
     SMALL CRAFT ADVISORY FROM 1 PM MONDAY TO 7 AM EST TUESDAY FOR
     ANZ254.

&&

$$
SYNOPSIS...WTB/RLG
NEAR TERM...RLG
SHORT TERM...RLG
LONG TERM...WTB
AVIATION...WTB/RLG
MARINE...WTB/RLG
TIDES/COASTAL FLOODING...




000
FXUS61 KBOX 212056
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
356 PM EST SUN DEC 21 2014

.SYNOPSIS...
SCATTERED SNOW/RAIN SHOWERS CONTINUE THROUGH MONDAY. WEAK LOW
PRESSURE WILL PASS SOUTH OF NEW ENGLAND BRINGING ANOTHER PERIOD OF
PRECIPITATION MONDAY NIGHT AND TUESDAY. A MUCH STRONGER STORM
PASSING WEST OF NEW ENGLAND WILL BRING HEAVY RAINFALL... GUSTY
WINDS AND COASTAL FLOODING CONCERNS TO THE REGION WEDNESDAY AND
WEDNESDAY NIGHT. DRY BUT VERY WINDY CONDITIONS FOLLOW FOR
CHRISTMAS DAY. HIGH PRESSURE BRINGS DRY WEATHER FRIDAY. ANOTHER
DEVELOPING SYSTEM MAY BRING RAIN AND SNOW NEXT SUNDAY.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
SHORTWAVE RIDGING BUILDS OVER SOUTHERN NEW ENGLAND OVERNIGHT. IN
ADDITION...HIGH PRESSURE IN QUEBEC BUILDS OVER THE REGION AS WELL.
THEREFORE...THERE WILL BE NO FOCUSING MECHANISM FOR PRECIP.
HOWEVER...ONSHORE FLOW AND DECENT MID LEVEL LAPSE RATES WILL ALLOW
FOR A FEW SCATTERED SNOW/RAIN SHOWERS ACROSS THE AREA OVERNIGHT.
EXPECT SNOW SHOWERS TO REMAIN ROUGHLY NORTH AND WEST OF A NEWPORT TO
TAUNTON TO SCITUATE LINE.  ANY ADDITIONAL SNOWFALL WILL AMOUNT TO A
DUSTING TO ABOUT AN INCH. TEMPERATURES WILL FALL INTO THE MID 20S
ACROSS THE NORTHWEST TO THE MID 30S ON THE CAPE AND ISLANDS.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
MONDAY...CLOUDY...DAMP...AND RAW CONDITIONS WILL CONTINUE THROUGH
THE DAY WITH CONTINUED ONSHORE FLOW AND SCATTERED SNOW/RAIN SHOWERS.

MONDAY NIGHT...WEAK LOW PRESSURE MOVING UP THE COAST TO JUST OFF THE
DELMARVA PENINSULA WILL PRODUCE WARM ADVECTION OVER SOUTHERN NEW
ENGLAND.  THIS IN TURN WILL LIKELY RESULT IN SOME PRECIPITATION
DEVELOPING OVERNIGHT.  HIGH PRESSURE MOVING INTO THE MARITIMES WILL
ALLOW FOR SOME COLD AIR DAMMING...PARTICULARLY INTO INTERIOR
SOUTHERN NEW ENGLAND.  THIS SCENARIO IS A GOOD SET UP FOR SOME
FREEZING RAIN ACROSS THE INTERIOR.  THE MAIN QUESTION IS HOW FAR
NORTH THE WARMER AIR GETS AS THIS WILL DETERMINE PTYPE.  FOR
NOW...WILL MAKE MENTION OF THE POTENTIAL FOR AN AREA OF FREEZING
RAIN IN THE HAZARDOUS WEATHER OUTLOOK. IF FREEZING RAIN LOOKS TO BE
MORE CERTAIN...WE WILL NEED TO ISSUE A WINTER WEATHER ADVISORY.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...

BIG PICTURE...

TUESDAY STARTS WITH UPPER RIDGES ON EACH COAST AND A DEEP UPPER
TROUGH/CLOSED LOW OVER THE PLAINS. BY WEDNESDAY THE CLOSED LOW
EJECTS NORTHEAST THROUGH LAKE SUPERIOR INTO CANADA. THIS SWEEPS THE
TROUGH AXIS EAST AND PASSES ACROSS NEW ENGLAND CHRISTMAS DAY.
ANOTHER SHORTWAVE MOVES ONSHORE IN THE PACIFIC NORTHWEST WEDNESDAY
AND PHASES WITH A SECOND DROPPING SOUTH FROM NORTHERN CANADA.  THIS
REESTABLISHES THE UPPER TROUGH OVER THE NORTHERN PLAINS/GREAT LAKES
SATURDAY.

CONTOUR HEIGHTS WILL BE ABOVE NORMAL MIDWEEK...TRENDING BELOW NORMAL
OVER THE WEEKEND AS THE SECOND UPPER TROUGH SHIFTS EAST. THIS POINTS
TO A COOLING TREND AFTER CHRISTMAS.

THE GFS AND ECMWF ARE SIMILAR IN HANDLING THE HOLIDAY STORM. THERE
ARE DIFFERENCES BETWEEN THE MODELS IN HANDLING THE SUNDAY SYSTEM. WE
USED A BLEND MOST OF THE LONG TERM PERIOD...BUT MANUALLY ADJUSTED
POPS FOR SUNDAY WITH LOW CONFIDENCE IN MODEL VALUES.

THE DAILIES...

TUESDAY... HIGH PRESSURE OVER THE MARITIMES WITH RIDGING DOWN THE
ATLANTIC COAST. COASTAL LOW PRESSURE WAVE DEVELOPS ALONG STALLED
WARM FRONT AND MOVES NORTH.  AS THE COASTAL LOW MOVES NORTH IT WILL
RUN UP AGAINST THE MARITIME HIGH. THIS WILL INCREASE THE LOW LEVEL
PRESSURE GRADIENT AND INCREASE THE LOW LEVEL SOUTHEAST WINDS.
RESULT...A SOUTHEAST LOW LEVEL JET RUNS OVER THE RIDGING ALONG THE
COASTAL PLAIN INDUCING LOW LEVEL LIFT. THE MOIST LAYER EXPANDS ABOVE
800 MB...NOT DEEP BUT DEEP ENOUGH FOR THE LIFT TO GENERATE LIGHT
PCPN. PTYPE WILL BE RAIN MOST PLACES...BUT THERE COULD BE SPOTS OF
LIGHT FREEZING RAIN IN NORTHWEST MASSACHUSETTS. WE WILL MAINTAIN
CHANCE POPS BUT INCREASE TO AROUND 50 PCT...THE HIGH END OF THE
CHANCE RANGE.

LOW LEVEL SOUTH JET MOVES UP THE COAST TUESDAY NIGHT REACHING THE
COOLER AIR OVER NEW ENGLAND AFTER MIDNIGHT AND BEFORE SUNRISE. THIS
WILL GENERATE ADDITIONAL LIFT AS WELL AS INCREASING AND DEEPENING
MOISTURE. THIS SUGGESTS INCREASING POPS OVERNIGHT.  TEMPERATURES
SHOULD REMAIN ABOVE FREEZING SO PTYPE SHOULD BE RAIN.

WEDNESDAY-THURSDAY... SOUTH 40-50 KNOT LOW LEVEL JET MOVES OVER NEW
ENGLAND WEDNESDAY GENERATING STRONG LIFT AND TRANSPORTING HIGH
VALUES OF PRECIPITABLE WATER INTO THAT LIFT. THE MOISTURE VALUES ARE
MORE THAN 3 STD DEVIATIONS ABOVE NORMAL FOR DECEMBER...AND ACTUALLY
NEAR THE MAXIMUM PREVIOUSLY OBSERVED VALUE. THIS SUGGESTS RAIN WITH
SOME HEAVY DOWNPOURS. COLD FRONT APPROACHES LATE WEDNESDAY NIGHT AND
CROSSES SOUTHERN NEW ENGLAND CHRISTMAS MORNING. THE FRONT WILL HAVE
DYNAMIC SUPPORT FROM A 140-150 KNOT UPPER JET. THE FOREWARD PROGRESS
OF THE FRONT WILL SLOW BECAUSE MOST OF THE MOTION IN THE UPPER JET
WILL BE PARALLEL TO THE FRONT. THIS WILL MEAN CONTINUED RAIN/HEAVY
RAIN THROUGH THE NIGHT INTO THURSDAY MORNING.

THE OBVIOUS CONCERN FOR THIS PERIOD WILL BE FLOODING FROM HEAVY
RAINFALL. RAIN AMOUNTS OF 2 TO 3 INCHES ARE EXPECTED. THIS SHOULD BE
SUFFICIENT FOR AT LEAST URBAN AND POOR DRAINAGE FLOODING. A FLOOD
WATCH MAY BE NEEDED.

A SECOND CONCERN WILL BE WIND. THE LOW LEVEL JET WEDNESDAY WILL BE
SOUTH 40-50 KNOTS...AND INCREASE TO 55-65 KNOTS WEDNESDAY NIGHT.
CONVENTIONAL MIXING WILL NOT BE DEEP...BUT HEAVY DOWNPOURS COULD
CREATE A MOIST ADIABATIC CHANNEL THAT BRINGS DOWN SOME STRONGER WIND
GUSTS. MODEL GRIDS ARE RATHER LIGHT ON WIND GUSTS...15 TO 30 KNOTS.
WE WILL MANUALLY ADJUST THESE VALUES UP TO 25-35 KNOTS OVER LAND AND
A LITTLE STRONGER OVER WATER.

A THIRD CONCERN WILL BE COASTAL FLOODING. MORE DETAILS ON THIS IN
THE TIDE/COASTAL FLOOD SECTION.

WINDS SHIFT TO WEST BEHIND THE FRONT ON CHRISTMAS DAY. THIS WILL
BRING DRIER AIR AND SO END THE RAINFALL. COLD ADVECTION WILL PROMOTE
MIXING TO NEAR 850 MB IN THE AFTERNOON AND TAP 25-35 KNOT WIND
GUSTS...POSSIBLY 40 KNOT GUSTS. A WIND ADVISORY MAY BE NEEDED FOR
THESE WEST WINDS THURSDAY.

FRIDAY THROUGH SUNDAY.... HIGH PRESSURE MOVES OVER THE REGION FRIDAY
BRINGING DRY WEATHER.  SHORTWAVE MOVING THROUGH THE GREAT LAKES
SWINGS A COLD FRONT THROUGH NEW ENGLAND SATURDAY. THE SURFACE
REFLECTION OF THE SHORTWAVE MOVES UP THE ST LAWRENCE VALLEY AND JET
SUPPPORT WILL MOSTLY BE NORTH OF THE BORDER...SO PCPN WILL BE
LIMITED.  QUESTION FOR SUNDAY WILL BE WHETHER A WAVE FORMS ON THE
DEPARTING COLD FRONT...IF SO IT MIGHT BRING PCPN TO NEW ENGLAND. THE
ECMWF THINKS SO BUT THE GFS DOES NOT. WE BROUGHT IN A CHANCE OF RAIN
AND SNOW SHOWERS.

&&

.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 /THROUGH MONDAY NIGHT/...

THROUGH TONIGHT...MODERATE CONFIDENCE. MAINLY MVFR/IFR CONDITIONS
THROUGH TONIGHT. EXCEPTION RIGHT NOW IS THE CAPE AND ISLANDS WHERE
VFR CONDITIONS ARE IN PLACE. BELIEVE CONDITIONS WILL DETERIORATE
LATER TONIGHT THERE. WIDESPREAD LIGHT SNOW SHOWERS ARE AFFECTING
ALL OF SOUTHERN NEW ENGLAND THIS AFTERNOON. EXPECT THIS ACTIVITY
TO BECOME MORE SCATTERED IN NATURE. RAIN SHOWERS ACROSS MOST OF
PLYMOUTH COUNTY AND ONTO THE CAPE/ISLANDS WITH SNOW SHOWERS NORTH
AND WEST.

MONDAY AND MONDAY NIGHT...MODERATE CONFIDENCE. MAINLY MVFR
CONDITIONS CONTINUE IN SCATTERED LIGHT SNOW SHOWERS. LIGHT FZRA
POSSIBLE LATE MONDAY NIGHT ACROSS NW MASSACHUSETTS.

KBOS TERMINAL...MODERATE CONFIDENCE.

KBDL TERMINAL...MODERATE CONFIDENCE.

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

TUESDAY...MVFR CIGS AND VSBYS IN LIGHT RAIN.  EAST SOUTHEAST
WINDS...WITH FREQUENT GUSTS TO 25 KNOTS ON THE CAPE AND ISLANDS.

LATE TUESDAY NIGHT-WEDNESDAY-THURSDAY... CONDITIONS LOWERING TO
IFR/LIFR IN RAIN/HEAVY RAIN. SOUTHEAST WINDS GUSTING 25 TO 35 KNOTS
WEDNESDAY AND SOUTH WINDS SIMILAR SPEEDS WEDNESDAY NIGHT...EXCEPT 30
TO 40 KNOTS CAPE COD AND ISLANDS. WINDS AT 2000 FEET MAY REACH 55 TO
65 KNOTS BY WEDNESDAY NIGHT CREATING LOW LEVEL WIND SHEAR. ISOLATED
THUNDERSTORMS WEDNESDAY AFTERNOON AND NIGHT. COLD FRONT SWINGS
THROUGH ON THURSDAY MORNING BRINGING A WIND SHIFT TO WEST WITH GUSTS
30-40 KNOTS.  CONDITIONS IMPROVE TO VFR AFTER THE WIND SHIFT.

FRIDAY...
VFR.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

HIGH PRESSURE ACROSS QUEBEC AND THE MARITIMES WILL RESULT IN
PERSISTENT NORTHEASTERLY TO EASTERLY WINDS ACROSS THE WATERS THROUGH
MONDAY.  THIS WILL RESULT IN BUILDING SEAS ON THE EASTERN WATERS
DESPITE WIND GUSTS UP TO 20 KNOTS.  SEAS BUILD TO AT LEAST 5 FEET ON
THE EASTERN WATERS BY MIDDAY MONDAY.  HAVE ISSUED A SMALL CRAFT
ADVISORY FOR THE EASTERN WATERS BEGINNING MIDDAY MONDAY AND
CONTINUING THROUGH TUESDAY MORNING.  WINDS INCREASE TO NEAR 25 KTS
ON THE SOUTHERN WATERS BY 12Z TUESDAY.

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

TUESDAY...EAST WIND GUSTING TO 25 KNOTS...BECOMING SOUTHEAST AT
NIGHT. SEAS 5 TO 7 FEET ON THE EXPOSED WATERS.  A SMALL CRAFT
ADVISORY WILL BE NEEDED.

WEDNESDAY-THURSDAY... SOUTH WINDS WITH FREQUENT GUSTS 35 TO 40 KNOTS
BY WEDNESDAY AFTERNOON AND CONTINUING THROUGH THE NIGHT. WINDS SHIFT
WEST THURSDAY MORNING WITH SIMILAR SPEEDS THROUGH THE AFTERNOON.
SEAS WILL BUILD TO 7 TO 12 FEET ON THE EXPOSED WATERS BY WEDNESDAY
NIGHT AND THURSDAY.  A GALE WARNING MAY BE NEEDED.

FRIDAY...WINDS DIMINISHING TO 25 KNOTS FRIDAY MORNING AND BELOW 25
KNOTS BY AFTERNOON.  SEAS LINGERING AT 5 TO 7 FEET ON THE EXPOSED
WATERS. A SMALL CRAFT ADVISORY MAY BE NEEDED.

&&

.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES WILL OCCUR TUESDAY THROUGH THURSDAY.

TUESDAY...HIGH TIDE AT BOSTON WILL BE 11.6 FT. WINDS WILL BE FROM
THE EAST...SO THERE WILL BE ONSHORE FLOW DURING THIS HIGH TIDE
ALLOWING FOR MINOR SPLASHOVER. IF WINDS INCREASE THEN COULD SEE
SOME POCKETS OF MINOR COASTAL FLOODING.

WEDNESDAY...WINDS SHIFT TO A MORE SOUTHEASTERLY FLOW DURING THE DAY
AND INCREASE QUICKLY AS AN APPROACHING SYSTEM BRINGS PRESSURE
FALLS OF 1 MB/HR. THE WEDNESDAY AFTERNOON HIGH TIDE IN BOSTON IS
11.7 FT AND STRONG SOUTHEASTERLY WINDS WILL BE JUST OFFSHORE.
RIGHT NOW BELIEVE MINOR COASTAL FLOODING IS POSSIBLE ALONG THE
EAST COAST.

WEDNESDAY EVENING...SOUTHERLY WINDS ARE EXPECTED AND ASTRONOMICAL
TIDES INCREASE ALONG THE SOUTH COAST. HIGH TIDE IN PROVIDENCE WILL
BE 5.2 FT. 925 MB LLJ STRENGTHENS TO 55-65 KTS WHICH COULD PUSH A
DECENT SURGE UP ALONG THE SOUTH COAST DURING THE TIME OF HIGH
TIDE. THINKING THAT MINOR COASTAL FLOODING COULD OCCUR BUT CANNOT
RULE OUT MODERATE ALONG THE SOUTH COAST...ESPECIALLY IF LLJ
CONTINUES TO STRENGTHEN.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 4 PM MONDAY TO 7 AM EST TUESDAY FOR
     ANZ250.
     SMALL CRAFT ADVISORY FROM 10 PM MONDAY TO 7 AM EST TUESDAY FOR
     ANZ251-255.
     SMALL CRAFT ADVISORY FROM 1 PM MONDAY TO 7 AM EST TUESDAY FOR
     ANZ254.

&&

$$
SYNOPSIS...WTB/RLG
NEAR TERM...RLG
SHORT TERM...RLG
LONG TERM...WTB
AVIATION...WTB/RLG
MARINE...WTB/RLG
TIDES/COASTAL FLOODING...





000
FXUS61 KBOX 212024
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
324 PM EST SUN DEC 21 2014

.SYNOPSIS...
SCATTERED SNOW/RAIN SHOWERS CONTINUE THROUGH THIS AFTERNOON. WEAK
LOW PRESSURE WILL PASS SOUTH OF NEW ENGLAND BRINGING ANOTHER
PERIOD OF PRECIPITATION MONDAY NIGHT AND TUESDAY. A MUCH STRONGER
STORM PASSING WEST OF NEW ENGLAND WILL BRING HEAVY RAINFALL...
GUSTY WINDS AND COASTAL FLOODING CONCERNS TO THE REGION WEDNESDAY
AND WEDNESDAY NIGHT. DRY BUT VERY WINDY CONDITIONS FOLLOW FOR
CHRISTMAS DAY.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
SHORTWAVE RIDGING BUILDS OVER SOUTHERN NEW ENGLAND OVERNIGHT. IN
ADDITION...HIGH PRESSURE IN QUEBEC BUILDS OVER THE REGION AS WELL.
THEREFORE...THERE WILL BE NO FOCUSING MECHANISM FOR PRECIP.
HOWEVER...ONSHORE FLOW AND DECENT MID LEVEL LAPSE RATES WILL ALLOW
FOR A FEW SCATTERED SNOW/RAIN SHOWERS ACROSS THE AREA OVERNIGHT.
EXPECT SNOW SHOWERS TO REMAIN ROUGHLY NORTH AND WEST OF A NEWPORT TO
TAUNTON TO SCITUATE LINE.  ANY ADDITIONAL SNOWFALL WILL AMOUNT TO A
DUSTING TO ABOUT AN INCH. TEMPERATURES WILL FALL INTO THE MID 20S
ACROSS THE NORTHWEST TO THE MID 30S ON THE CAPE AND ISLANDS.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
MONDAY...CLOUDY...DAMP...AND RAW CONDITIONS WILL CONTINUE THROUGH
THE DAY WITH CONTINUED ONSHORE FLOW AND SCATTERED SNOW/RAIN SHOWERS.

MONDAY NIGHT...WEAK LOW PRESSURE MOVING UP THE COAST TO JUST OFF THE
DELMARVA PENINSULA WILL PRODUCE WARM ADVECTION OVER SOUTHERN NEW
ENGLAND.  THIS IN TURN WILL LIKELY RESULT IN SOME PRECIPITATION
DEVELOPING OVERNIGHT.  HIGH PRESSURE MOVING INTO THE MARITIMES WILL
ALLOW FOR SOME COLD AIR DAMMING...PARTICULARLY INTO INTERIOR
SOUTHERN NEW ENGLAND.  THIS SCENARIO IS A GOOD SET UP FOR SOME
FREEZING RAIN ACROSS THE INTERIOR.  THE MAIN QUESTION IS HOW FAR
NORTH THE WARMER AIR GETS AS THIS WILL DETERMINE PTYPE.  FOR
NOW...WILL MAKE MENTION OF THE POTENTIAL FOR AN AREA OF FREEZING
RAIN IN THE HAZARDOUS WEATHER OUTLOOK. IF FREEZING RAIN LOOKS TO BE
MORE CERTAIN...WE WILL NEED TO ISSUE A WINTER WEATHER ADVISORY.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
HIGHLIGHTS...

* WEAK SHORTWAVE ON MON NIGHT/TUESDAY COULD BRING WINTRY
  MIX/FREEZING RAIN TO THE INTERIOR
* ANOMALOUS SYSTEM ACROSS THE GREAT LAKES WILL BRING HEAVY
  RAIN...GUSTY WINDS AND COASTAL FLOODING CONCERNS AROUND CHRISTMAS
  EVE
* BLUSTERY BUT AIRMASS WILL BE DRYING OUT ON CHRISTMAS DAY

OVERVIEW...

THE MODELS AND ENSEMBLES OFFER A REASONABLY SIMILAR AND PREDICTABLE
LARGER SCALE MID TO UPPER LEVEL PATTERN EVOLUTION FOR MUCH OF THE
UPCOMING WEEK. THIS ACTIVE FLOW REGIME DEVELOPS SEVERAL MID-UPPER
LEVEL TROUGH AND ASSOCIATED/UNSETTLING LEAD SURFACE LOW/FRONTAL
SYSTEMS AND PCPN SWATHS PROGRESS STEADILY ACROSS THE LOWER 48. THE
FIRST AMPLIFIED/DEEP LEAD SYSTEM WORKS ACROSS THE ERN/NERN US INTO
ERN CANADA CHRISTMAS EVE INTO CHRISTMAS ALLOWING FOR A MOIST/WARMED
AIRMASS IN ADVANCE OF FRONTAL APPROACH WITH HEAVIEST LEAD QPF
POTENTIAL OVER NEW ENGLAND. BIGGEST QUESTION IS THE EVOLUTION OF THE
SECONDARY LOW PRESSURE SYSTEM. 00Z GUIDANCE HAS BACKED OFF ON THE
STRENGTH OF THE LOW AND IS HAVING ISSUES ON HOW TO HANDLE ITS
EVOLUTION. THE EC AND GFS HAVE SLOWED DOWN THE SYSTEM SLIGHTLY WITH
THE EC HAVING MORE OF A NEGATIVE TROUGH VS THE GFS. BELIEVE THE
UKMET IS A GOOD COMPROMISE AT IS WAS THE FIRST DETERMINISTIC
GUIDANCE ON TAMPERING DOWN THE FIRST MAIN LOW...WHILE THE CMC IS OUT
TO LUNCH. REGARDLESS THIS IS A VERY ANOMALOUS SYSTEM THAT IS ABOUT 4
STANDARD DEVIATIONS AWAY.

A SECONDARY SYSTEM DEEPENS ACROSS THE FOUR CORNERS ON FRIDAY AND
WITH THE STUBBORN TROUGH OVER THE CENTRAL U.S...IT WILL PUSH A
SYSTEM TOWARDS SOUTHERN NEW ENGLAND BY SUNDAY. THIS SYSTEM MAY
SUPPORT A MODEST SWATH OF OVERRUNNING SNOW OVER SOUTHERN NEW
ENGLAND.

DETAILS...

TUESDAY...MODERATE CONFIDENCE.

A WEAK WAVE OF LOW PRESSURE DEVELOPS ALONG THE SOUTHEAST COAST
MONDAY...AND WILL BE ON A DEVELOPING WARM FRONTAL BOUNDARY. THIS LOW
REMAINS WEAK AS THE WARM FRONT MOVES SLOWLY NORTH MONDAY NIGHT INTO
TUESDAY. APPEARS THAT THERE IS DECENT WARM ADVECTION AHEAD OF THIS
WAVE. SEVERAL HI-RES GUIDANCE MODELS SHOW THAT THERE IS THE
POTENTIAL FOR COLD AIR DAMMING ACROSS THE INTERIOR INTO TUESDAY.
BIGGEST QUESTION WILL BE IS THERE ENOUGH MOISTURE FOR PRECIP DURING
THIS TIME FRAME. DUE TO A STRENGTHENING LLJ PROVIDING A GOOD SOURCE OF
LIFT ANTICIPATE PRECIP TO DEVELOP AND OVERSPREAD ACROSS SOUTHERN NEW
ENGLAND. IF THIS PLAYS OUT WITH COLD AIR DAMMING AND WARM AIR
ADVECTION...THEN WE COULD SEE FREEZING RAIN/DRIZZLE ACROSS THE I-91
CORRIDOR LATE MONDAY INTO TUESDAY MORNING. DURING THE DAY ON
TUESDAY...GOOD AMOUNT OF WARM AIR WILL PUSH SURFACE TEMPS ABOVE
FREEZING BY THE LATE MORNING ALLOWING FOR ANY PRECIP TO BE MORE OF
THE LIQUID VARIETY AHEAD OF THE CHRISTMAS EVE STORM. HOWEVER
GUIDANCE IS ALWAYS TOO FAST IN SCOURING TEMPS OUT ESP ACROSS THE CT
VALLEY SO WE WILL NEED TO MONITOR THIS CLOSELY...ESP DUE TO LIGHT
WINDS AND THE HIGH IN EASTERN CANADA. A WINTER WX ADVISORY MAY BE
NEEDED FOR THE LIGHT ICING POTENTIAL.

WE COULD ALSO SEE SOME MINOR COASTAL FLOODING CONCERNS ON TUESDAY. SEE
BELOW FOR MORE DETAILS.

WEDNESDAY INTO THURSDAY...HIGH CONFIDENCE IN SYSTEM LOW CONFIDENCE
ON DETAILS.

ANOMALOUS SYSTEM WILL STRENGTHEN OVER THE GREAT LAKES TUESDAY INTO
WEDNESDAY. A SECONDARY SHORTWAVE WILL ROUND THE DEEP TROUGH AND
DEVELOP A SECONDARY LOW PRESSURE ALONG THE COLD FRONT. THIS
SECONDARY LOW WILL STRENGTHEN AND PASS WEST OF SOUTHERN NEW ENGLAND.
THIS SYSTEM WILL CONTINUE TO DEEPEN AS IT MOVES TOWARDS EASTERN
CANADA SWINGING A COLD FRONT ACROSS THE NORTHEAST.

STRONG SOUTHERLY JET OUT AHEAD OF THE FRONT WITH A GULF MOISTURE
CONNECTION WILL IMPACT SOUTHERN NEW ENGLAND ON CHRISTMAS EVE. THIS
STRONG JET WILL YIELD FOR PCPN IN THE LIQUID VARIETY.  PW ANOMALIES
ARE BETWEEN +4 TO +5 STANDARD DEVIATIONS ABOVE NORMAL WHICH IS QUITE
ANOMALOUS FOR THIS TIME OF YEAR. IN FACT CURRENT PWATS ARE PROGGED
ABOVE 1.6 INCHES WITH MODEL QPF OVER 2 INCHES...AT THE VERY LEAST
COULD SEE URBAN AND POOR DRAINAGE FLOODING. LATEST EC EVEN SHOWS
OVER 2.5 INCHES OF QPF...AND WITH THE TROPICAL CONNECTION AND STRONG
SOUTHERLY FLOW COULD SEE HIGHER AMOUNTS DUE TO TOPOGRAPHY
ENHANCEMENTS. RAINFALL RECORDS MAY FALL IF EVERYTHING FALLS INTO
PLACE.

AHEAD OF THE FRONT...SOUTHERN NEW ENGLAND WILL WARM SECTOR WED INTO
THUR MORNING ALLOWING FOR TEMPERATURES TO BE WELL ABOVE AVERAGE. IN
FACT WE MAY BE CLOSE AT BREAKING RECORD HIGH TEMPS IF TEMPS WARM TO
60F OR ABOVE ON CHRISTMAS EVE. SINCE WE WILL BE IN THE WARM
SECTOR...AND SHOWALTERS CLOSE TO ZERO...ISOLATED THUNDER IS STILL
POSSIBLE.

STRONG LOW LEVEL WINDS WILL ALSO BE A CONCERN ESPECIALLY WEDNESDAY
NIGHT. THE ECMWF SHOWS EAST-SOUTHEAST WINDS 30-40 KNOTS ON WEDNESDAY
INCREASING TO 60-75 KNOTS BY WEDNESDAY NIGHT. STRONG DOWNPOURS MAY
OVERCOME THE LOW LEVEL INVERSION AND BRING STRONG GUSTS OF AT LEAST
30-40 KNOTS ESPECIALLY ALONG THE SOUTH COAST. A WIND ADVISORY MAY BE
NEEDED IN SOME AREAS.

CHRISTMAS DAY...MODERATE CONFIDENCE.

AS THE COLD FRONT PASSES THROUGH EARLY CHRISTMAS DAY...THE WEST
WINDS WILL HELP DRY THE AIRMASS ALLOWING FOR PARTLY SUNNY SKIES.
STRONG CAA ON THURSDAY WILL ALLOW DESCENT MIXING. WINDS IN THE SFC-
850 MB LAYER WILL BE 30-40 KNOTS AND POSSIBLY A LITTLE
HIGHER...WHICH WOULD REQUIRE A WIND ADVISORY FOR MUCH OF THE AREA.

FRIDAY-SUNDAY...LOWER CONFIDENCE

WEAK HIGH PRESSURE BUILDS OVER THE AREA FRIDAY INTO SATURDAY. THE
NEXT SHORTWAVE APPROACHES LATE SATURDAY INTO SUNDAY AND SHOULD BRING
INCREASING CLOUDS FROM WEST TO EAST ALONG WITH A CHANCE OF RAIN OR
SNOW SHOWERS MAINLY IN THE AFTERNOON AND AT NIGHT.

&&

.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /THROUGH MONDAY NIGHT/...

THROUGH TONIGHT...MODERATE CONFIDENCE. MAINLY MVFR/IFR CONDITIONS
THROUGH TONIGHT. EXCEPTION RIGHT NOW IS THE CAPE AND ISLANDS WHERE
VFR CONDITIONS ARE IN PLACE. BELIEVE CONDITIONS WILL DETERIORATE
LATER TONIGHT THERE. WIDESPREAD LIGHT SNOW SHOWERS ARE AFFECTING
ALL OF SOUTHERN NEW ENGLAND THIS AFTERNOON. EXPECT THIS ACTIVITY
TO BECOME MORE SCATTERED IN NATURE. RAIN SHOWERS ACROSS MOST OF
PLYMOUTH COUNTY AND ONTO THE CAPE/ISLANDS WITH SNOW SHOWERS NORTH
AND WEST.

MONDAY AND MONDAY NIGHT...MODERATE CONFIDENCE. MAINLY MVFR
CONDITIONS CONTINUE IN SCATTERED LIGHT SNOW SHOWERS. LIGHT FZRA
POSSIBLE LATE MONDAY NIGHT ACROSS NW MASSACHUSETTS.

KBOS TERMINAL...MODERATE CONFIDENCE.

KBDL TERMINAL...MODERATE CONFIDENCE.

OUTLOOK...MONDAY THROUGH THURSDAY...MODERATE CONFIDENCE.

MONDAY...MVFR CIGS CONTINUE IN RI/EASTERN MASS IN MARINE EAST FLOW.
VFR IN THE WEST.

TUESDAY...VFR WITH SCATTERED MVFR IN ANY RAIN/SNOW SHOWERS.

WEDNESDAY...CONDITIONS LOWERING TO IFR IN RAIN/HEAVY RAIN. ISOLATED
THUNDERSTORMS POSSIBLE ESPECIALLY WEDNESDAY NIGHT. EAST-SOUTHEAST
SURFACE WINDS MAY GUST TO 35-45 KNOTS. WINDS AT 2000 FEET AGL WILL
REACH 50-60 KNOTS WEDNESDAY AFTERNOON AND EARLY NIGHT CREATING LOW
LEVEL WIND SHEAR CONCERNS.

CHRISTMAS DAY...WEST WIND GUSTING 30-40 KNOTS. CONDITIONS IMPROVING
TO VFR AS THE WIND BRINGS IN COOLER DRIER AIR.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

HIGH PRESSURE ACROSS QUEBEC AND THE MARITIMES WILL RESULT IN
PERSISTENT NORTHEASTERLY TO EASTERLY WINDS ACROSS THE WATERS THROUGH
MONDAY.  THIS WILL RESULT IN BUILDING SEAS ON THE EASTERN WATERS
DESPITE WIND GUSTS UP TO 20 KNOTS.  SEAS BUILD TO AT LEAST 5 FEET ON
THE EASTERN WATERS BY MIDDAY MONDAY.  HAVE ISSUED A SMALL CRAFT
ADVISORY FOR THE EASTERN WATERS BEGINNING MIDDAY MONDAY AND
CONTINUING THROUGH TUESDAY MORNING.  WINDS INCREASE TO NEAR 25 KTS
ON THE SOUTHERN WATERS BY 12Z TUESDAY.

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

MONDAY...EAST TO NORTHEAST WINDS GUSTING AROUND 15 KNOTS OR LESS.
SEAS WILL HOLD AROUND 3-4 FEET...MAY INCREASE TO 5FT IN NORTHEAST
FLOW AS GUIDANCE MAY BE UNDERDONE.

TUESDAY... INCREASING EAST WINDS WITH FREQUENT GUSTS 25 TO 30 KNOTS.
SEAS WILL BUILD TO 5-6 FEET ON THE EXPOSED WATERS.  A SMALL CRAFT
ADVISORY MAY BE NEEDED.

WEDNESDAY...RAIN WILL BE HEAVY AT TIMES PRODUCING POOR VISIBILITY.
INCREASING SOUTHEAST WINDS 20-25 SUSTAINED AND 40 KNOT GUSTS.  WINDS
SHOULD SHIFT TO SOUTH WEDNESDAY NIGHT AND SOUTHWEST TOWARD THURSDAY
MORNING. RAIN WILL TAPER OFF WITH THE WIND SHIFT TO SOUTHWEST. SEAS
WILL CONTINUE TO BUILD WITH 7-11 FEET HEIGHTS ON THE EXPOSED WATERS.
A GALE WARNING WILL BE NEEDED...WITH A LOW PROB OF A FEW STORM FORCE
GUSTS ACROSS THE EASTERN OUTER WATERS.

CHRISTMAS DAY... WEST SOUTHWEST WINDS WILL CONTINUE TO GUST 35-40
KNOTS...SO A CONTINUED GALE WARNING MAY BE NEEDED. SEAS OF 7-15 FEET
ARE POSSIBLE ON THE EXPOSED WATERS...AND 5 FEET IS POSSIBLE ON SOME
OF THE NEARSHORE WATERS.

&&

.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES WILL OCCUR TUESDAY THROUGH THURSDAY.

TUESDAY...HIGH TIDE AT BOSTON WILL BE 11.6 FT. THERE WILL BE ONSHORE
FLOW DURING THIS HIGH TIDE ALLOWING FOR MINOR SPLASHOVER. IF WINDS
INCREASE THEN COULD SEE SOME POCKETS OF MINOR COASTAL FLOODING.

WEDNESDAY...WINDS SHIFT TO A MORE SOUTHEASTERLY FLOW DURING THE DAY
AND INCREASE QUICKLY AS AN APPROACHING SYSTEM BRINGS DECENT PRESSURE
FALLS. THE WEDNESDAY AFTERNOON HIGH TIDE IN BOSTON IS 11.7 FT AND
STRONG SOUTHEASTERLY WINDS WILL BE JUST OFFSHORE. RIGHT NOW BELIEVE
MINOR COASTAL FLOODING IS POSSIBLE ALONG THE EAST COAST.

WEDNESDAY EVENING...SOUTHERLY WINDS ARE EXPECTED AND ASTRONOMICAL
TIDES INCREASE ALONG THE SOUTH COAST. HIGH TIDE IN PROVIDENCE WILL
BE 5.2 FT. 925 MB LLJ STRENGTHENS TO 50-60 KTS WHICH COULD PUSH A
DECENT SURGE UP ALONG THE SOUTH COAST DURING THE TIME OF HIGH TIDE.
THINKING THAT MINOR COASTAL FLOODING COULD OCCUR BUT CANNOT RULE OUT
MODERATE ALONG THE SOUTH COAST...ESPECIALLY IF LLJ CONTINUES TO
STRENGTHEN.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...DUNTEN/RLG
NEAR TERM...RLG
SHORT TERM...RLG
LONG TERM...DUNTEN
AVIATION...DUNTEN/RLG
MARINE...DUNTEN/RLG
TIDES/COASTAL FLOODING...




000
FXUS61 KBOX 212024
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
324 PM EST SUN DEC 21 2014

.SYNOPSIS...
SCATTERED SNOW/RAIN SHOWERS CONTINUE THROUGH THIS AFTERNOON. WEAK
LOW PRESSURE WILL PASS SOUTH OF NEW ENGLAND BRINGING ANOTHER
PERIOD OF PRECIPITATION MONDAY NIGHT AND TUESDAY. A MUCH STRONGER
STORM PASSING WEST OF NEW ENGLAND WILL BRING HEAVY RAINFALL...
GUSTY WINDS AND COASTAL FLOODING CONCERNS TO THE REGION WEDNESDAY
AND WEDNESDAY NIGHT. DRY BUT VERY WINDY CONDITIONS FOLLOW FOR
CHRISTMAS DAY.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
SHORTWAVE RIDGING BUILDS OVER SOUTHERN NEW ENGLAND OVERNIGHT. IN
ADDITION...HIGH PRESSURE IN QUEBEC BUILDS OVER THE REGION AS WELL.
THEREFORE...THERE WILL BE NO FOCUSING MECHANISM FOR PRECIP.
HOWEVER...ONSHORE FLOW AND DECENT MID LEVEL LAPSE RATES WILL ALLOW
FOR A FEW SCATTERED SNOW/RAIN SHOWERS ACROSS THE AREA OVERNIGHT.
EXPECT SNOW SHOWERS TO REMAIN ROUGHLY NORTH AND WEST OF A NEWPORT TO
TAUNTON TO SCITUATE LINE.  ANY ADDITIONAL SNOWFALL WILL AMOUNT TO A
DUSTING TO ABOUT AN INCH. TEMPERATURES WILL FALL INTO THE MID 20S
ACROSS THE NORTHWEST TO THE MID 30S ON THE CAPE AND ISLANDS.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
MONDAY...CLOUDY...DAMP...AND RAW CONDITIONS WILL CONTINUE THROUGH
THE DAY WITH CONTINUED ONSHORE FLOW AND SCATTERED SNOW/RAIN SHOWERS.

MONDAY NIGHT...WEAK LOW PRESSURE MOVING UP THE COAST TO JUST OFF THE
DELMARVA PENINSULA WILL PRODUCE WARM ADVECTION OVER SOUTHERN NEW
ENGLAND.  THIS IN TURN WILL LIKELY RESULT IN SOME PRECIPITATION
DEVELOPING OVERNIGHT.  HIGH PRESSURE MOVING INTO THE MARITIMES WILL
ALLOW FOR SOME COLD AIR DAMMING...PARTICULARLY INTO INTERIOR
SOUTHERN NEW ENGLAND.  THIS SCENARIO IS A GOOD SET UP FOR SOME
FREEZING RAIN ACROSS THE INTERIOR.  THE MAIN QUESTION IS HOW FAR
NORTH THE WARMER AIR GETS AS THIS WILL DETERMINE PTYPE.  FOR
NOW...WILL MAKE MENTION OF THE POTENTIAL FOR AN AREA OF FREEZING
RAIN IN THE HAZARDOUS WEATHER OUTLOOK. IF FREEZING RAIN LOOKS TO BE
MORE CERTAIN...WE WILL NEED TO ISSUE A WINTER WEATHER ADVISORY.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
HIGHLIGHTS...

* WEAK SHORTWAVE ON MON NIGHT/TUESDAY COULD BRING WINTRY
  MIX/FREEZING RAIN TO THE INTERIOR
* ANOMALOUS SYSTEM ACROSS THE GREAT LAKES WILL BRING HEAVY
  RAIN...GUSTY WINDS AND COASTAL FLOODING CONCERNS AROUND CHRISTMAS
  EVE
* BLUSTERY BUT AIRMASS WILL BE DRYING OUT ON CHRISTMAS DAY

OVERVIEW...

THE MODELS AND ENSEMBLES OFFER A REASONABLY SIMILAR AND PREDICTABLE
LARGER SCALE MID TO UPPER LEVEL PATTERN EVOLUTION FOR MUCH OF THE
UPCOMING WEEK. THIS ACTIVE FLOW REGIME DEVELOPS SEVERAL MID-UPPER
LEVEL TROUGH AND ASSOCIATED/UNSETTLING LEAD SURFACE LOW/FRONTAL
SYSTEMS AND PCPN SWATHS PROGRESS STEADILY ACROSS THE LOWER 48. THE
FIRST AMPLIFIED/DEEP LEAD SYSTEM WORKS ACROSS THE ERN/NERN US INTO
ERN CANADA CHRISTMAS EVE INTO CHRISTMAS ALLOWING FOR A MOIST/WARMED
AIRMASS IN ADVANCE OF FRONTAL APPROACH WITH HEAVIEST LEAD QPF
POTENTIAL OVER NEW ENGLAND. BIGGEST QUESTION IS THE EVOLUTION OF THE
SECONDARY LOW PRESSURE SYSTEM. 00Z GUIDANCE HAS BACKED OFF ON THE
STRENGTH OF THE LOW AND IS HAVING ISSUES ON HOW TO HANDLE ITS
EVOLUTION. THE EC AND GFS HAVE SLOWED DOWN THE SYSTEM SLIGHTLY WITH
THE EC HAVING MORE OF A NEGATIVE TROUGH VS THE GFS. BELIEVE THE
UKMET IS A GOOD COMPROMISE AT IS WAS THE FIRST DETERMINISTIC
GUIDANCE ON TAMPERING DOWN THE FIRST MAIN LOW...WHILE THE CMC IS OUT
TO LUNCH. REGARDLESS THIS IS A VERY ANOMALOUS SYSTEM THAT IS ABOUT 4
STANDARD DEVIATIONS AWAY.

A SECONDARY SYSTEM DEEPENS ACROSS THE FOUR CORNERS ON FRIDAY AND
WITH THE STUBBORN TROUGH OVER THE CENTRAL U.S...IT WILL PUSH A
SYSTEM TOWARDS SOUTHERN NEW ENGLAND BY SUNDAY. THIS SYSTEM MAY
SUPPORT A MODEST SWATH OF OVERRUNNING SNOW OVER SOUTHERN NEW
ENGLAND.

DETAILS...

TUESDAY...MODERATE CONFIDENCE.

A WEAK WAVE OF LOW PRESSURE DEVELOPS ALONG THE SOUTHEAST COAST
MONDAY...AND WILL BE ON A DEVELOPING WARM FRONTAL BOUNDARY. THIS LOW
REMAINS WEAK AS THE WARM FRONT MOVES SLOWLY NORTH MONDAY NIGHT INTO
TUESDAY. APPEARS THAT THERE IS DECENT WARM ADVECTION AHEAD OF THIS
WAVE. SEVERAL HI-RES GUIDANCE MODELS SHOW THAT THERE IS THE
POTENTIAL FOR COLD AIR DAMMING ACROSS THE INTERIOR INTO TUESDAY.
BIGGEST QUESTION WILL BE IS THERE ENOUGH MOISTURE FOR PRECIP DURING
THIS TIME FRAME. DUE TO A STRENGTHENING LLJ PROVIDING A GOOD SOURCE OF
LIFT ANTICIPATE PRECIP TO DEVELOP AND OVERSPREAD ACROSS SOUTHERN NEW
ENGLAND. IF THIS PLAYS OUT WITH COLD AIR DAMMING AND WARM AIR
ADVECTION...THEN WE COULD SEE FREEZING RAIN/DRIZZLE ACROSS THE I-91
CORRIDOR LATE MONDAY INTO TUESDAY MORNING. DURING THE DAY ON
TUESDAY...GOOD AMOUNT OF WARM AIR WILL PUSH SURFACE TEMPS ABOVE
FREEZING BY THE LATE MORNING ALLOWING FOR ANY PRECIP TO BE MORE OF
THE LIQUID VARIETY AHEAD OF THE CHRISTMAS EVE STORM. HOWEVER
GUIDANCE IS ALWAYS TOO FAST IN SCOURING TEMPS OUT ESP ACROSS THE CT
VALLEY SO WE WILL NEED TO MONITOR THIS CLOSELY...ESP DUE TO LIGHT
WINDS AND THE HIGH IN EASTERN CANADA. A WINTER WX ADVISORY MAY BE
NEEDED FOR THE LIGHT ICING POTENTIAL.

WE COULD ALSO SEE SOME MINOR COASTAL FLOODING CONCERNS ON TUESDAY. SEE
BELOW FOR MORE DETAILS.

WEDNESDAY INTO THURSDAY...HIGH CONFIDENCE IN SYSTEM LOW CONFIDENCE
ON DETAILS.

ANOMALOUS SYSTEM WILL STRENGTHEN OVER THE GREAT LAKES TUESDAY INTO
WEDNESDAY. A SECONDARY SHORTWAVE WILL ROUND THE DEEP TROUGH AND
DEVELOP A SECONDARY LOW PRESSURE ALONG THE COLD FRONT. THIS
SECONDARY LOW WILL STRENGTHEN AND PASS WEST OF SOUTHERN NEW ENGLAND.
THIS SYSTEM WILL CONTINUE TO DEEPEN AS IT MOVES TOWARDS EASTERN
CANADA SWINGING A COLD FRONT ACROSS THE NORTHEAST.

STRONG SOUTHERLY JET OUT AHEAD OF THE FRONT WITH A GULF MOISTURE
CONNECTION WILL IMPACT SOUTHERN NEW ENGLAND ON CHRISTMAS EVE. THIS
STRONG JET WILL YIELD FOR PCPN IN THE LIQUID VARIETY.  PW ANOMALIES
ARE BETWEEN +4 TO +5 STANDARD DEVIATIONS ABOVE NORMAL WHICH IS QUITE
ANOMALOUS FOR THIS TIME OF YEAR. IN FACT CURRENT PWATS ARE PROGGED
ABOVE 1.6 INCHES WITH MODEL QPF OVER 2 INCHES...AT THE VERY LEAST
COULD SEE URBAN AND POOR DRAINAGE FLOODING. LATEST EC EVEN SHOWS
OVER 2.5 INCHES OF QPF...AND WITH THE TROPICAL CONNECTION AND STRONG
SOUTHERLY FLOW COULD SEE HIGHER AMOUNTS DUE TO TOPOGRAPHY
ENHANCEMENTS. RAINFALL RECORDS MAY FALL IF EVERYTHING FALLS INTO
PLACE.

AHEAD OF THE FRONT...SOUTHERN NEW ENGLAND WILL WARM SECTOR WED INTO
THUR MORNING ALLOWING FOR TEMPERATURES TO BE WELL ABOVE AVERAGE. IN
FACT WE MAY BE CLOSE AT BREAKING RECORD HIGH TEMPS IF TEMPS WARM TO
60F OR ABOVE ON CHRISTMAS EVE. SINCE WE WILL BE IN THE WARM
SECTOR...AND SHOWALTERS CLOSE TO ZERO...ISOLATED THUNDER IS STILL
POSSIBLE.

STRONG LOW LEVEL WINDS WILL ALSO BE A CONCERN ESPECIALLY WEDNESDAY
NIGHT. THE ECMWF SHOWS EAST-SOUTHEAST WINDS 30-40 KNOTS ON WEDNESDAY
INCREASING TO 60-75 KNOTS BY WEDNESDAY NIGHT. STRONG DOWNPOURS MAY
OVERCOME THE LOW LEVEL INVERSION AND BRING STRONG GUSTS OF AT LEAST
30-40 KNOTS ESPECIALLY ALONG THE SOUTH COAST. A WIND ADVISORY MAY BE
NEEDED IN SOME AREAS.

CHRISTMAS DAY...MODERATE CONFIDENCE.

AS THE COLD FRONT PASSES THROUGH EARLY CHRISTMAS DAY...THE WEST
WINDS WILL HELP DRY THE AIRMASS ALLOWING FOR PARTLY SUNNY SKIES.
STRONG CAA ON THURSDAY WILL ALLOW DESCENT MIXING. WINDS IN THE SFC-
850 MB LAYER WILL BE 30-40 KNOTS AND POSSIBLY A LITTLE
HIGHER...WHICH WOULD REQUIRE A WIND ADVISORY FOR MUCH OF THE AREA.

FRIDAY-SUNDAY...LOWER CONFIDENCE

WEAK HIGH PRESSURE BUILDS OVER THE AREA FRIDAY INTO SATURDAY. THE
NEXT SHORTWAVE APPROACHES LATE SATURDAY INTO SUNDAY AND SHOULD BRING
INCREASING CLOUDS FROM WEST TO EAST ALONG WITH A CHANCE OF RAIN OR
SNOW SHOWERS MAINLY IN THE AFTERNOON AND AT NIGHT.

&&

.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /THROUGH MONDAY NIGHT/...

THROUGH TONIGHT...MODERATE CONFIDENCE. MAINLY MVFR/IFR CONDITIONS
THROUGH TONIGHT. EXCEPTION RIGHT NOW IS THE CAPE AND ISLANDS WHERE
VFR CONDITIONS ARE IN PLACE. BELIEVE CONDITIONS WILL DETERIORATE
LATER TONIGHT THERE. WIDESPREAD LIGHT SNOW SHOWERS ARE AFFECTING
ALL OF SOUTHERN NEW ENGLAND THIS AFTERNOON. EXPECT THIS ACTIVITY
TO BECOME MORE SCATTERED IN NATURE. RAIN SHOWERS ACROSS MOST OF
PLYMOUTH COUNTY AND ONTO THE CAPE/ISLANDS WITH SNOW SHOWERS NORTH
AND WEST.

MONDAY AND MONDAY NIGHT...MODERATE CONFIDENCE. MAINLY MVFR
CONDITIONS CONTINUE IN SCATTERED LIGHT SNOW SHOWERS. LIGHT FZRA
POSSIBLE LATE MONDAY NIGHT ACROSS NW MASSACHUSETTS.

KBOS TERMINAL...MODERATE CONFIDENCE.

KBDL TERMINAL...MODERATE CONFIDENCE.

OUTLOOK...MONDAY THROUGH THURSDAY...MODERATE CONFIDENCE.

MONDAY...MVFR CIGS CONTINUE IN RI/EASTERN MASS IN MARINE EAST FLOW.
VFR IN THE WEST.

TUESDAY...VFR WITH SCATTERED MVFR IN ANY RAIN/SNOW SHOWERS.

WEDNESDAY...CONDITIONS LOWERING TO IFR IN RAIN/HEAVY RAIN. ISOLATED
THUNDERSTORMS POSSIBLE ESPECIALLY WEDNESDAY NIGHT. EAST-SOUTHEAST
SURFACE WINDS MAY GUST TO 35-45 KNOTS. WINDS AT 2000 FEET AGL WILL
REACH 50-60 KNOTS WEDNESDAY AFTERNOON AND EARLY NIGHT CREATING LOW
LEVEL WIND SHEAR CONCERNS.

CHRISTMAS DAY...WEST WIND GUSTING 30-40 KNOTS. CONDITIONS IMPROVING
TO VFR AS THE WIND BRINGS IN COOLER DRIER AIR.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

HIGH PRESSURE ACROSS QUEBEC AND THE MARITIMES WILL RESULT IN
PERSISTENT NORTHEASTERLY TO EASTERLY WINDS ACROSS THE WATERS THROUGH
MONDAY.  THIS WILL RESULT IN BUILDING SEAS ON THE EASTERN WATERS
DESPITE WIND GUSTS UP TO 20 KNOTS.  SEAS BUILD TO AT LEAST 5 FEET ON
THE EASTERN WATERS BY MIDDAY MONDAY.  HAVE ISSUED A SMALL CRAFT
ADVISORY FOR THE EASTERN WATERS BEGINNING MIDDAY MONDAY AND
CONTINUING THROUGH TUESDAY MORNING.  WINDS INCREASE TO NEAR 25 KTS
ON THE SOUTHERN WATERS BY 12Z TUESDAY.

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

MONDAY...EAST TO NORTHEAST WINDS GUSTING AROUND 15 KNOTS OR LESS.
SEAS WILL HOLD AROUND 3-4 FEET...MAY INCREASE TO 5FT IN NORTHEAST
FLOW AS GUIDANCE MAY BE UNDERDONE.

TUESDAY... INCREASING EAST WINDS WITH FREQUENT GUSTS 25 TO 30 KNOTS.
SEAS WILL BUILD TO 5-6 FEET ON THE EXPOSED WATERS.  A SMALL CRAFT
ADVISORY MAY BE NEEDED.

WEDNESDAY...RAIN WILL BE HEAVY AT TIMES PRODUCING POOR VISIBILITY.
INCREASING SOUTHEAST WINDS 20-25 SUSTAINED AND 40 KNOT GUSTS.  WINDS
SHOULD SHIFT TO SOUTH WEDNESDAY NIGHT AND SOUTHWEST TOWARD THURSDAY
MORNING. RAIN WILL TAPER OFF WITH THE WIND SHIFT TO SOUTHWEST. SEAS
WILL CONTINUE TO BUILD WITH 7-11 FEET HEIGHTS ON THE EXPOSED WATERS.
A GALE WARNING WILL BE NEEDED...WITH A LOW PROB OF A FEW STORM FORCE
GUSTS ACROSS THE EASTERN OUTER WATERS.

CHRISTMAS DAY... WEST SOUTHWEST WINDS WILL CONTINUE TO GUST 35-40
KNOTS...SO A CONTINUED GALE WARNING MAY BE NEEDED. SEAS OF 7-15 FEET
ARE POSSIBLE ON THE EXPOSED WATERS...AND 5 FEET IS POSSIBLE ON SOME
OF THE NEARSHORE WATERS.

&&

.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES WILL OCCUR TUESDAY THROUGH THURSDAY.

TUESDAY...HIGH TIDE AT BOSTON WILL BE 11.6 FT. THERE WILL BE ONSHORE
FLOW DURING THIS HIGH TIDE ALLOWING FOR MINOR SPLASHOVER. IF WINDS
INCREASE THEN COULD SEE SOME POCKETS OF MINOR COASTAL FLOODING.

WEDNESDAY...WINDS SHIFT TO A MORE SOUTHEASTERLY FLOW DURING THE DAY
AND INCREASE QUICKLY AS AN APPROACHING SYSTEM BRINGS DECENT PRESSURE
FALLS. THE WEDNESDAY AFTERNOON HIGH TIDE IN BOSTON IS 11.7 FT AND
STRONG SOUTHEASTERLY WINDS WILL BE JUST OFFSHORE. RIGHT NOW BELIEVE
MINOR COASTAL FLOODING IS POSSIBLE ALONG THE EAST COAST.

WEDNESDAY EVENING...SOUTHERLY WINDS ARE EXPECTED AND ASTRONOMICAL
TIDES INCREASE ALONG THE SOUTH COAST. HIGH TIDE IN PROVIDENCE WILL
BE 5.2 FT. 925 MB LLJ STRENGTHENS TO 50-60 KTS WHICH COULD PUSH A
DECENT SURGE UP ALONG THE SOUTH COAST DURING THE TIME OF HIGH TIDE.
THINKING THAT MINOR COASTAL FLOODING COULD OCCUR BUT CANNOT RULE OUT
MODERATE ALONG THE SOUTH COAST...ESPECIALLY IF LLJ CONTINUES TO
STRENGTHEN.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...DUNTEN/RLG
NEAR TERM...RLG
SHORT TERM...RLG
LONG TERM...DUNTEN
AVIATION...DUNTEN/RLG
MARINE...DUNTEN/RLG
TIDES/COASTAL FLOODING...





000
FXUS61 KBOX 211801
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
101 PM EST SUN DEC 21 2014

.SYNOPSIS...
SCATTERED SNOW/RAIN SHOWERS CONTINUE THROUGH THIS AFTERNOON. WEAK
LOW PRESSURE WILL PASS SOUTH OF NEW ENGLAND BRINGING ANOTHER
PERIOD OF PRECIPITATION MONDAY NIGHT AND TUESDAY. A MUCH STRONGER
STORM PASSING WEST OF NEW ENGLAND WILL BRING HEAVY RAINFALL...
GUSTY WINDS AND COASTAL FLOODING CONCERNS TO THE REGION WEDNESDAY
AND WEDNESDAY NIGHT. DRY BUT VERY WINDY CONDITIONS FOLLOW FOR
CHRISTMAS DAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
1 PM UPDATE...WIDESPREAD LIGHT SNOW SHOWERS CONTINUE ACROSS
SOUTHERN NEW ENGLAND. SNOW IS LIGHT AND WITH TEMPERATURES AT OR
JUST ABOVE FREEZING...SNOW IS NOT ACCUMULATING ON PAVEMENT MOST
LOCATIONS AND IN SOME PLACES...NOT EVEN ON THE GRASS. SHOWERS ARE
TAKING THE FORM OF RAIN ACROSS PORTIONS OF PLYMOUTH COUNTY AS WELL
AS THE CAPE AND ISLANDS.

THE SHORTWAVE IS MOVING INTO NORTHERN NEW ENGLAND NOW SO EXPECT
SHOWERS TO BECOME MORE SCATTERED IN NATURE. HOWEVER...THERE IS
QUITE A BIT OF LOW LEVEL MOISTURE AND ENOUGH LIFT THAT SHOWERS
WILL CONTINUE.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
TONIGHT...

A RATHER CLOUDY AND RAW NIGHT ACROSS SOUTHERN NEW ENGLAND.  WHILE
THERE IS NOT A SIGNIFICANT SHORTWAVE TO TRIGGER A LOT OF
PRECIPITATION...PLENTY OF LOW LEVEL MOISTURE/WEAK SHALLOW LIFT
REMAINS.  THIS MAY BE ENOUGH TO RESULT IN A FEW RAIN/SNOW SHOWER
FROM TIME TO TIME.  PTYPE...WOULD BE MAINLY SNOW SHOWERS EXCEPT TO
THE SOUTHEAST OF A NEWPORT...TO TAUNTON...TO JUST NORTH OF
MARSHFIELD LINE.  AGAIN...MUCH OF THE NIGHT WILL PROBABLY END UP
DRY...BUT JUST THE RISK FOR A FEW RAIN/SNOW SHOWERS.

&&

.LONG TERM /MONDAY THROUGH SUNDAY/...
HIGHLIGHTS...

* WEAK SHORTWAVE ON MON NIGHT/TUESDAY COULD BRING WINTRY
  MIX/FREEZING RAIN TO THE INTERIOR
* ANOMALOUS SYSTEM ACROSS THE GREAT LAKES WILL BRING HEAVY
  RAIN...GUSTY WINDS AND COASTAL FLOODING CONCERNS AROUND CHRISTMAS
  EVE
* BLUSTERY BUT AIRMASS WILL BE DRYING OUT ON CHRISTMAS DAY

OVERVIEW...

THE MODELS AND ENSEMBLES OFFER A REASONABLY SIMILAR AND PREDICTABLE
LARGER SCALE MID TO UPPER LEVEL PATTERN EVOLUTION FOR MUCH OF THE
UPCOMING WEEK. THIS ACTIVE FLOW REGIME DEVELOPS SEVERAL MID-UPPER
LEVEL TROUGH AND ASSOCIATED/UNSETTLING LEAD SURFACE LOW/FRONTAL
SYSTEMS AND PCPN SWATHS PROGRESS STEADILY ACROSS THE LOWER 48. THE
FIRST AMPLIFIED/DEEP LEAD SYSTEM WORKS ACROSS THE ERN/NERN US INTO
ERN CANADA CHRISTMAS EVE INTO CHRISTMAS ALLOWING FOR A MOIST/WARMED
AIRMASS IN ADVANCE OF FRONTAL APPROACH WITH HEAVIEST LEAD QPF
POTENTIAL OVER NEW ENGLAND. BIGGEST QUESTION IS THE EVOLUTION OF THE
SECONDARY LOW PRESSURE SYSTEM. 00Z GUIDANCE HAS BACKED OFF ON THE
STRENGTH OF THE LOW AND IS HAVING ISSUES ON HOW TO HANDLE ITS
EVOLUTION. THE EC AND GFS HAVE SLOWED DOWN THE SYSTEM SLIGHTLY WITH
THE EC HAVING MORE OF A NEGATIVE TROUGH VS THE GFS. BELIEVE THE
UKMET IS A GOOD COMPROMISE AT IS WAS THE FIRST DETERMINISTIC
GUIDANCE ON TAMPERING DOWN THE FIRST MAIN LOW...WHILE THE CMC IS OUT
TO LUNCH. REGARDLESS THIS IS A VERY ANOMALOUS SYSTEM THAT IS ABOUT 4
STANDARD DEVIATIONS AWAY.

A SECONDARY SYSTEM DEEPENS ACROSS THE FOUR CORNERS ON FRIDAY AND
WITH THE STUBBORN TROUGH OVER THE CENTRAL U.S...IT WILL PUSH A
SYSTEM TOWARDS SOUTHERN NEW ENGLAND BY SUNDAY. THIS SYSTEM MAY
SUPPORT A MODEST SWATH OF OVERRUNNING SNOW OVER SOUTHERN NEW
ENGLAND.

DETAILS...

MONDAY INTO TUESDAY...MODERATE CONFIDENCE.

A WEAK WAVE OF LOW PRESSURE DEVELOPS ALONG THE SOUTHEAST COAST
MONDAY...AND WILL BE ON A DEVELOPING WARM FRONTAL BOUNDARY. THIS LOW
REMAINS WEAK AS THE WARM FRONT MOVES SLOWLY NORTH MONDAY NIGHT INTO
TUESDAY. APPEARS THAT THERE IS DECENT WARM ADVECTION AHEAD OF THIS
WAVE. SEVERAL HI-RES GUIDANCE MODELS SHOW THAT THERE IS THE
POTENTIAL FOR COLD AIR DAMMING ACROSS THE INTERIOR INTO TUESDAY.
BIGGEST QUESTION WILL BE IS THERE ENOUGH MOISTURE FOR PRECIP DURING
THIS TIME FRAME. DUE TO A STRENGTHENING LLJ PROVIDING A GOOD SOURCE OF
LIFT ANTICIPATE PRECIP TO DEVELOP AND OVERSPREAD ACROSS SOUTHERN NEW
ENGLAND. IF THIS PLAYS OUT WITH COLD AIR DAMMING AND WARM AIR
ADVECTION...THEN WE COULD SEE FREEZING RAIN/DRIZZLE ACROSS THE I-91
CORRIDOR LATE MONDAY INTO TUESDAY MORNING. DURING THE DAY ON
TUESDAY...GOOD AMOUNT OF WARM AIR WILL PUSH SURFACE TEMPS ABOVE
FREEZING BY THE LATE MORNING ALLOWING FOR ANY PRECIP TO BE MORE OF
THE LIQUID VARIETY AHEAD OF THE CHRISTMAS EVE STORM. HOWEVER
GUIDANCE IS ALWAYS TOO FAST IN SCOURING TEMPS OUT ESP ACROSS THE CT
VALLEY SO WE WILL NEED TO MONITOR THIS CLOSELY...ESP DUE TO LIGHT
WINDS AND THE HIGH IN EASTERN CANADA. A WINTER WX ADVISORY MAY BE
NEEDED FOR THE LIGHT ICING POTENTIAL.

WE COULD ALSO SEE SOME MINOR COASTAL FLOODING CONCERNS ON TUESDAY. SEE
BELOW FOR MORE DETAILS.

WEDNESDAY INTO THURSDAY...HIGH CONFIDENCE IN SYSTEM LOW CONFIDENCE
ON DETAILS.

ANOMALOUS SYSTEM WILL STRENGTHEN OVER THE GREAT LAKES TUESDAY INTO
WEDNESDAY. A SECONDARY SHORTWAVE WILL ROUND THE DEEP TROUGH AND
DEVELOP A SECONDARY LOW PRESSURE ALONG THE COLD FRONT. THIS
SECONDARY LOW WILL STRENGTHEN AND PASS WEST OF SOUTHERN NEW ENGLAND.
THIS SYSTEM WILL CONTINUE TO DEEPEN AS IT MOVES TOWARDS EASTERN
CANADA SWINGING A COLD FRONT ACROSS THE NORTHEAST.

STRONG SOUTHERLY JET OUT AHEAD OF THE FRONT WITH A GULF MOISTURE
CONNECTION WILL IMPACT SOUTHERN NEW ENGLAND ON CHRISTMAS EVE. THIS
STRONG JET WILL YIELD FOR PCPN IN THE LIQUID VARIETY.  PW ANOMALIES
ARE BETWEEN +4 TO +5 STANDARD DEVIATIONS ABOVE NORMAL WHICH IS QUITE
ANOMALOUS FOR THIS TIME OF YEAR. IN FACT CURRENT PWATS ARE PROGGED
ABOVE 1.6 INCHES WITH MODEL QPF OVER 2 INCHES...AT THE VERY LEAST
COULD SEE URBAN AND POOR DRAINAGE FLOODING. LATEST EC EVEN SHOWS
OVER 2.5 INCHES OF QPF...AND WITH THE TROPICAL CONNECTION AND STRONG
SOUTHERLY FLOW COULD SEE HIGHER AMOUNTS DUE TO TOPOGRAPHY
ENHANCEMENTS. RAINFALL RECORDS MAY FALL IF EVERYTHING FALLS INTO
PLACE.

AHEAD OF THE FRONT...SOUTHERN NEW ENGLAND WILL WARM SECTOR WED INTO
THUR MORNING ALLOWING FOR TEMPERATURES TO BE WELL ABOVE AVERAGE. IN
FACT WE MAY BE CLOSE AT BREAKING RECORD HIGH TEMPS IF TEMPS WARM TO
60F OR ABOVE ON CHRISTMAS EVE. SINCE WE WILL BE IN THE WARM
SECTOR...AND SHOWALTERS CLOSE TO ZERO...ISOLATED THUNDER IS STILL
POSSIBLE.

STRONG LOW LEVEL WINDS WILL ALSO BE A CONCERN ESPECIALLY WEDNESDAY
NIGHT. THE ECMWF SHOWS EAST-SOUTHEAST WINDS 30-40 KNOTS ON WEDNESDAY
INCREASING TO 60-75 KNOTS BY WEDNESDAY NIGHT. STRONG DOWNPOURS MAY
OVERCOME THE LOW LEVEL INVERSION AND BRING STRONG GUSTS OF AT LEAST
30-40 KNOTS ESPECIALLY ALONG THE SOUTH COAST. A WIND ADVISORY MAY BE
NEEDED IN SOME AREAS.

CHRISTMAS DAY...MODERATE CONFIDENCE.

AS THE COLD FRONT PASSES THROUGH EARLY CHRISTMAS DAY...THE WEST
WINDS WILL HELP DRY THE AIRMASS ALLOWING FOR PARTLY SUNNY SKIES.
STRONG CAA ON THURSDAY WILL ALLOW DESCENT MIXING. WINDS IN THE SFC-
850 MB LAYER WILL BE 30-40 KNOTS AND POSSIBLY A LITTLE
HIGHER...WHICH WOULD REQUIRE A WIND ADVISORY FOR MUCH OF THE AREA.

FRIDAY-SUNDAY...LOWER CONFIDENCE

WEAK HIGH PRESSURE BUILDS OVER THE AREA FRIDAY INTO SATURDAY. THE
NEXT SHORTWAVE APPROACHES LATE SATURDAY INTO SUNDAY AND SHOULD BRING
INCREASING CLOUDS FROM WEST TO EAST ALONG WITH A CHANCE OF RAIN OR
SNOW SHOWERS MAINLY IN THE AFTERNOON AND AT NIGHT.

&&

.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/...

MODERATE CONFIDENCE. MAINLY MVFR/IFR CONDITIONS THROUGH TONIGHT.
EXCEPTION RIGHT NOW IS THE CAPE AND ISLANDS WHERE VFR CONDITIONS
ARE IN PLACE. BELIEVE CONDITIONS WILL DETERIORATE LATER TONIGHT
THERE. WIDESPREAD LIGHT SNOW SHOWERS ARE AFFECTING ALL OF SOUTHERN
NEW ENGLAND THIS AFTERNOON. EXPECT THIS ACTIVITY TO BECOME MORE
SCATTERED IN NATURE. RAIN SHOWERS ACROSS MOST OF PLYMOUTH COUNTY
AND ONTO THE CAPE/ISLANDS WITH SNOW SHOWERS NORTH AND WEST.

KBOS TERMINAL...MODERATE CONFIDENCE.

KBDL TERMINAL...MODERATE CONFIDENCE.

OUTLOOK...MONDAY THROUGH THURSDAY...MODERATE CONFIDENCE.

MONDAY...MVFR CIGS CONTINUE IN RI/EASTERN MASS IN MARINE EAST FLOW.
VFR IN THE WEST.

TUESDAY...VFR WITH SCATTERED MVFR IN ANY RAIN/SNOW SHOWERS.

WEDNESDAY...CONDITIONS LOWERING TO IFR IN RAIN/HEAVY RAIN. ISOLATED
THUNDERSTORMS POSSIBLE ESPECIALLY WEDNESDAY NIGHT. EAST-SOUTHEAST
SURFACE WINDS MAY GUST TO 35-45 KNOTS. WINDS AT 2000 FEET AGL WILL
REACH 50-60 KNOTS WEDNESDAY AFTERNOON AND EARLY NIGHT CREATING LOW
LEVEL WIND SHEAR CONCERNS.

CHRISTMAS DAY...WEST WIND GUSTING 30-40 KNOTS. CONDITIONS IMPROVING
TO VFR AS THE WIND BRINGS IN COOLER DRIER AIR.

&&

.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.

HIGH PRESSURE ACROSS QUEBEC WILL RESULT IN NORTHEAST WINDS ACROSS
THE WATERS THAT WILL GUST TO BETWEEN 15 AND 20 KNOTS.  THIS WILL
RESULT IN 2 TO 4 FOOT SEAS.  HOWEVER...NO HEADLINES PLANNED AS
CONDITIONS SHOULD REMAIN BELOW SMALL CRAFT ADVISORY THRESHOLDS.

OUTLOOK...MONDAY THROUGH THURSDAY...MODERATE CONFIDENCE

MONDAY...EAST TO NORTHEAST WINDS GUSTING AROUND 15 KNOTS OR LESS.
SEAS WILL HOLD AROUND 3-4 FEET...MAY INCREASE TO 5FT IN NORTHEAST
FLOW AS GUIDANCE MAY BE UNDERDONE.

TUESDAY... INCREASING EAST WINDS WITH FREQUENT GUSTS 25 TO 30 KNOTS.
SEAS WILL BUILD TO 5-6 FEET ON THE EXPOSED WATERS.  A SMALL CRAFT
ADVISORY MAY BE NEEDED.

WEDNESDAY...RAIN WILL BE HEAVY AT TIMES PRODUCING POOR VISIBILITY.
INCREASING SOUTHEAST WINDS 20-25 SUSTAINED AND 40 KNOT GUSTS.  WINDS
SHOULD SHIFT TO SOUTH WEDNESDAY NIGHT AND SOUTHWEST TOWARD THURSDAY
MORNING. RAIN WILL TAPER OFF WITH THE WIND SHIFT TO SOUTHWEST. SEAS
WILL CONTINUE TO BUILD WITH 7-11 FEET HEIGHTS ON THE EXPOSED WATERS.
A GALE WARNING WILL BE NEEDED...WITH A LOW PROB OF A FEW STORM FORCE
GUSTS ACROSS THE EASTERN OUTER WATERS.

CHRISTMAS DAY... WEST SOUTHWEST WINDS WILL CONTINUE TO GUST 35-40
KNOTS...SO A CONTINUED GALE WARNING MAY BE NEEDED. SEAS OF 7-15 FEET
ARE POSSIBLE ON THE EXPOSED WATERS...AND 5 FEET IS POSSIBLE ON SOME
OF THE NEARSHORE WATERS.

&&

.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES WILL OCCUR TUESDAY THROUGH THURSDAY. BREAKING
IT DOWN...ON TUESDAY HIGH TIDE AT BOSTON WILL BE 11.6 FT. THERE WILL
BE ONSHORE FLOW DURING THIS HIGH TIDE ALLOWING FOR MINOR SPLASHOVER.
IF WIND GUSTS INCREASE THEN COULD POSSIBLE SEE MINOR COASTAL
FLOODING.

ON WEDNESDAY...WINDS WILL SWITCH TO A MORE SOUTHEASTERLY FLOW DURING
THE DAY AND INCREASE QUICKLY FROM APPROACHING SYSTEM AND DECENT
PRESSURE FALLS. WEDNESDAY AFTERNOON HIGH TIDE IN BOSTON IS 11.7 FT
AND WITH ANY STRENGTH ON THE EASTERLY WIND FLOW WILL PUSH THE TIDE
OVER. RIGHT NOW BELIEVE MINOR COASTAL FLOODING IS POSSIBLE ALONG THE
EAST COASTLINE.

WEDNESDAY EVENING...THE WIND GOES IN A MORE SOUTHERLY DIRECTION AND
THE TIDE WILL BE INCREASE ACROSS THE SOUTH COAST. HIGH TIDE IN
PROVIDENCE WILL BE 5.2 FT. 925 MB LLJ STRENGTHENS TO 50-60 KTS WHICH
COULD PUSH A DECENT SURGE UP ALONG THE SOUTH COAST DURING THE TIME
OF HIGH TIDE. THINKING THAT MINOR COASTAL FLOODING COULD OCCUR BUT
CANNOT RULE OUT MODERATE ALONG THE SOUTH COAST...ESP IF LLJ
STRENGTHENS EVEN MORE.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...FRANK/DUNTEN
NEAR TERM...RLG
SHORT TERM...FRANK
LONG TERM...DUNTEN
AVIATION...DUNTEN/RLG
MARINE...FRANK/DUNTEN
TIDES/COASTAL FLOODING...





000
FXUS61 KBOX 211801
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
101 PM EST SUN DEC 21 2014

.SYNOPSIS...
SCATTERED SNOW/RAIN SHOWERS CONTINUE THROUGH THIS AFTERNOON. WEAK
LOW PRESSURE WILL PASS SOUTH OF NEW ENGLAND BRINGING ANOTHER
PERIOD OF PRECIPITATION MONDAY NIGHT AND TUESDAY. A MUCH STRONGER
STORM PASSING WEST OF NEW ENGLAND WILL BRING HEAVY RAINFALL...
GUSTY WINDS AND COASTAL FLOODING CONCERNS TO THE REGION WEDNESDAY
AND WEDNESDAY NIGHT. DRY BUT VERY WINDY CONDITIONS FOLLOW FOR
CHRISTMAS DAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
1 PM UPDATE...WIDESPREAD LIGHT SNOW SHOWERS CONTINUE ACROSS
SOUTHERN NEW ENGLAND. SNOW IS LIGHT AND WITH TEMPERATURES AT OR
JUST ABOVE FREEZING...SNOW IS NOT ACCUMULATING ON PAVEMENT MOST
LOCATIONS AND IN SOME PLACES...NOT EVEN ON THE GRASS. SHOWERS ARE
TAKING THE FORM OF RAIN ACROSS PORTIONS OF PLYMOUTH COUNTY AS WELL
AS THE CAPE AND ISLANDS.

THE SHORTWAVE IS MOVING INTO NORTHERN NEW ENGLAND NOW SO EXPECT
SHOWERS TO BECOME MORE SCATTERED IN NATURE. HOWEVER...THERE IS
QUITE A BIT OF LOW LEVEL MOISTURE AND ENOUGH LIFT THAT SHOWERS
WILL CONTINUE.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
TONIGHT...

A RATHER CLOUDY AND RAW NIGHT ACROSS SOUTHERN NEW ENGLAND.  WHILE
THERE IS NOT A SIGNIFICANT SHORTWAVE TO TRIGGER A LOT OF
PRECIPITATION...PLENTY OF LOW LEVEL MOISTURE/WEAK SHALLOW LIFT
REMAINS.  THIS MAY BE ENOUGH TO RESULT IN A FEW RAIN/SNOW SHOWER
FROM TIME TO TIME.  PTYPE...WOULD BE MAINLY SNOW SHOWERS EXCEPT TO
THE SOUTHEAST OF A NEWPORT...TO TAUNTON...TO JUST NORTH OF
MARSHFIELD LINE.  AGAIN...MUCH OF THE NIGHT WILL PROBABLY END UP
DRY...BUT JUST THE RISK FOR A FEW RAIN/SNOW SHOWERS.

&&

.LONG TERM /MONDAY THROUGH SUNDAY/...
HIGHLIGHTS...

* WEAK SHORTWAVE ON MON NIGHT/TUESDAY COULD BRING WINTRY
  MIX/FREEZING RAIN TO THE INTERIOR
* ANOMALOUS SYSTEM ACROSS THE GREAT LAKES WILL BRING HEAVY
  RAIN...GUSTY WINDS AND COASTAL FLOODING CONCERNS AROUND CHRISTMAS
  EVE
* BLUSTERY BUT AIRMASS WILL BE DRYING OUT ON CHRISTMAS DAY

OVERVIEW...

THE MODELS AND ENSEMBLES OFFER A REASONABLY SIMILAR AND PREDICTABLE
LARGER SCALE MID TO UPPER LEVEL PATTERN EVOLUTION FOR MUCH OF THE
UPCOMING WEEK. THIS ACTIVE FLOW REGIME DEVELOPS SEVERAL MID-UPPER
LEVEL TROUGH AND ASSOCIATED/UNSETTLING LEAD SURFACE LOW/FRONTAL
SYSTEMS AND PCPN SWATHS PROGRESS STEADILY ACROSS THE LOWER 48. THE
FIRST AMPLIFIED/DEEP LEAD SYSTEM WORKS ACROSS THE ERN/NERN US INTO
ERN CANADA CHRISTMAS EVE INTO CHRISTMAS ALLOWING FOR A MOIST/WARMED
AIRMASS IN ADVANCE OF FRONTAL APPROACH WITH HEAVIEST LEAD QPF
POTENTIAL OVER NEW ENGLAND. BIGGEST QUESTION IS THE EVOLUTION OF THE
SECONDARY LOW PRESSURE SYSTEM. 00Z GUIDANCE HAS BACKED OFF ON THE
STRENGTH OF THE LOW AND IS HAVING ISSUES ON HOW TO HANDLE ITS
EVOLUTION. THE EC AND GFS HAVE SLOWED DOWN THE SYSTEM SLIGHTLY WITH
THE EC HAVING MORE OF A NEGATIVE TROUGH VS THE GFS. BELIEVE THE
UKMET IS A GOOD COMPROMISE AT IS WAS THE FIRST DETERMINISTIC
GUIDANCE ON TAMPERING DOWN THE FIRST MAIN LOW...WHILE THE CMC IS OUT
TO LUNCH. REGARDLESS THIS IS A VERY ANOMALOUS SYSTEM THAT IS ABOUT 4
STANDARD DEVIATIONS AWAY.

A SECONDARY SYSTEM DEEPENS ACROSS THE FOUR CORNERS ON FRIDAY AND
WITH THE STUBBORN TROUGH OVER THE CENTRAL U.S...IT WILL PUSH A
SYSTEM TOWARDS SOUTHERN NEW ENGLAND BY SUNDAY. THIS SYSTEM MAY
SUPPORT A MODEST SWATH OF OVERRUNNING SNOW OVER SOUTHERN NEW
ENGLAND.

DETAILS...

MONDAY INTO TUESDAY...MODERATE CONFIDENCE.

A WEAK WAVE OF LOW PRESSURE DEVELOPS ALONG THE SOUTHEAST COAST
MONDAY...AND WILL BE ON A DEVELOPING WARM FRONTAL BOUNDARY. THIS LOW
REMAINS WEAK AS THE WARM FRONT MOVES SLOWLY NORTH MONDAY NIGHT INTO
TUESDAY. APPEARS THAT THERE IS DECENT WARM ADVECTION AHEAD OF THIS
WAVE. SEVERAL HI-RES GUIDANCE MODELS SHOW THAT THERE IS THE
POTENTIAL FOR COLD AIR DAMMING ACROSS THE INTERIOR INTO TUESDAY.
BIGGEST QUESTION WILL BE IS THERE ENOUGH MOISTURE FOR PRECIP DURING
THIS TIME FRAME. DUE TO A STRENGTHENING LLJ PROVIDING A GOOD SOURCE OF
LIFT ANTICIPATE PRECIP TO DEVELOP AND OVERSPREAD ACROSS SOUTHERN NEW
ENGLAND. IF THIS PLAYS OUT WITH COLD AIR DAMMING AND WARM AIR
ADVECTION...THEN WE COULD SEE FREEZING RAIN/DRIZZLE ACROSS THE I-91
CORRIDOR LATE MONDAY INTO TUESDAY MORNING. DURING THE DAY ON
TUESDAY...GOOD AMOUNT OF WARM AIR WILL PUSH SURFACE TEMPS ABOVE
FREEZING BY THE LATE MORNING ALLOWING FOR ANY PRECIP TO BE MORE OF
THE LIQUID VARIETY AHEAD OF THE CHRISTMAS EVE STORM. HOWEVER
GUIDANCE IS ALWAYS TOO FAST IN SCOURING TEMPS OUT ESP ACROSS THE CT
VALLEY SO WE WILL NEED TO MONITOR THIS CLOSELY...ESP DUE TO LIGHT
WINDS AND THE HIGH IN EASTERN CANADA. A WINTER WX ADVISORY MAY BE
NEEDED FOR THE LIGHT ICING POTENTIAL.

WE COULD ALSO SEE SOME MINOR COASTAL FLOODING CONCERNS ON TUESDAY. SEE
BELOW FOR MORE DETAILS.

WEDNESDAY INTO THURSDAY...HIGH CONFIDENCE IN SYSTEM LOW CONFIDENCE
ON DETAILS.

ANOMALOUS SYSTEM WILL STRENGTHEN OVER THE GREAT LAKES TUESDAY INTO
WEDNESDAY. A SECONDARY SHORTWAVE WILL ROUND THE DEEP TROUGH AND
DEVELOP A SECONDARY LOW PRESSURE ALONG THE COLD FRONT. THIS
SECONDARY LOW WILL STRENGTHEN AND PASS WEST OF SOUTHERN NEW ENGLAND.
THIS SYSTEM WILL CONTINUE TO DEEPEN AS IT MOVES TOWARDS EASTERN
CANADA SWINGING A COLD FRONT ACROSS THE NORTHEAST.

STRONG SOUTHERLY JET OUT AHEAD OF THE FRONT WITH A GULF MOISTURE
CONNECTION WILL IMPACT SOUTHERN NEW ENGLAND ON CHRISTMAS EVE. THIS
STRONG JET WILL YIELD FOR PCPN IN THE LIQUID VARIETY.  PW ANOMALIES
ARE BETWEEN +4 TO +5 STANDARD DEVIATIONS ABOVE NORMAL WHICH IS QUITE
ANOMALOUS FOR THIS TIME OF YEAR. IN FACT CURRENT PWATS ARE PROGGED
ABOVE 1.6 INCHES WITH MODEL QPF OVER 2 INCHES...AT THE VERY LEAST
COULD SEE URBAN AND POOR DRAINAGE FLOODING. LATEST EC EVEN SHOWS
OVER 2.5 INCHES OF QPF...AND WITH THE TROPICAL CONNECTION AND STRONG
SOUTHERLY FLOW COULD SEE HIGHER AMOUNTS DUE TO TOPOGRAPHY
ENHANCEMENTS. RAINFALL RECORDS MAY FALL IF EVERYTHING FALLS INTO
PLACE.

AHEAD OF THE FRONT...SOUTHERN NEW ENGLAND WILL WARM SECTOR WED INTO
THUR MORNING ALLOWING FOR TEMPERATURES TO BE WELL ABOVE AVERAGE. IN
FACT WE MAY BE CLOSE AT BREAKING RECORD HIGH TEMPS IF TEMPS WARM TO
60F OR ABOVE ON CHRISTMAS EVE. SINCE WE WILL BE IN THE WARM
SECTOR...AND SHOWALTERS CLOSE TO ZERO...ISOLATED THUNDER IS STILL
POSSIBLE.

STRONG LOW LEVEL WINDS WILL ALSO BE A CONCERN ESPECIALLY WEDNESDAY
NIGHT. THE ECMWF SHOWS EAST-SOUTHEAST WINDS 30-40 KNOTS ON WEDNESDAY
INCREASING TO 60-75 KNOTS BY WEDNESDAY NIGHT. STRONG DOWNPOURS MAY
OVERCOME THE LOW LEVEL INVERSION AND BRING STRONG GUSTS OF AT LEAST
30-40 KNOTS ESPECIALLY ALONG THE SOUTH COAST. A WIND ADVISORY MAY BE
NEEDED IN SOME AREAS.

CHRISTMAS DAY...MODERATE CONFIDENCE.

AS THE COLD FRONT PASSES THROUGH EARLY CHRISTMAS DAY...THE WEST
WINDS WILL HELP DRY THE AIRMASS ALLOWING FOR PARTLY SUNNY SKIES.
STRONG CAA ON THURSDAY WILL ALLOW DESCENT MIXING. WINDS IN THE SFC-
850 MB LAYER WILL BE 30-40 KNOTS AND POSSIBLY A LITTLE
HIGHER...WHICH WOULD REQUIRE A WIND ADVISORY FOR MUCH OF THE AREA.

FRIDAY-SUNDAY...LOWER CONFIDENCE

WEAK HIGH PRESSURE BUILDS OVER THE AREA FRIDAY INTO SATURDAY. THE
NEXT SHORTWAVE APPROACHES LATE SATURDAY INTO SUNDAY AND SHOULD BRING
INCREASING CLOUDS FROM WEST TO EAST ALONG WITH A CHANCE OF RAIN OR
SNOW SHOWERS MAINLY IN THE AFTERNOON AND AT NIGHT.

&&

.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/...

MODERATE CONFIDENCE. MAINLY MVFR/IFR CONDITIONS THROUGH TONIGHT.
EXCEPTION RIGHT NOW IS THE CAPE AND ISLANDS WHERE VFR CONDITIONS
ARE IN PLACE. BELIEVE CONDITIONS WILL DETERIORATE LATER TONIGHT
THERE. WIDESPREAD LIGHT SNOW SHOWERS ARE AFFECTING ALL OF SOUTHERN
NEW ENGLAND THIS AFTERNOON. EXPECT THIS ACTIVITY TO BECOME MORE
SCATTERED IN NATURE. RAIN SHOWERS ACROSS MOST OF PLYMOUTH COUNTY
AND ONTO THE CAPE/ISLANDS WITH SNOW SHOWERS NORTH AND WEST.

KBOS TERMINAL...MODERATE CONFIDENCE.

KBDL TERMINAL...MODERATE CONFIDENCE.

OUTLOOK...MONDAY THROUGH THURSDAY...MODERATE CONFIDENCE.

MONDAY...MVFR CIGS CONTINUE IN RI/EASTERN MASS IN MARINE EAST FLOW.
VFR IN THE WEST.

TUESDAY...VFR WITH SCATTERED MVFR IN ANY RAIN/SNOW SHOWERS.

WEDNESDAY...CONDITIONS LOWERING TO IFR IN RAIN/HEAVY RAIN. ISOLATED
THUNDERSTORMS POSSIBLE ESPECIALLY WEDNESDAY NIGHT. EAST-SOUTHEAST
SURFACE WINDS MAY GUST TO 35-45 KNOTS. WINDS AT 2000 FEET AGL WILL
REACH 50-60 KNOTS WEDNESDAY AFTERNOON AND EARLY NIGHT CREATING LOW
LEVEL WIND SHEAR CONCERNS.

CHRISTMAS DAY...WEST WIND GUSTING 30-40 KNOTS. CONDITIONS IMPROVING
TO VFR AS THE WIND BRINGS IN COOLER DRIER AIR.

&&

.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.

HIGH PRESSURE ACROSS QUEBEC WILL RESULT IN NORTHEAST WINDS ACROSS
THE WATERS THAT WILL GUST TO BETWEEN 15 AND 20 KNOTS.  THIS WILL
RESULT IN 2 TO 4 FOOT SEAS.  HOWEVER...NO HEADLINES PLANNED AS
CONDITIONS SHOULD REMAIN BELOW SMALL CRAFT ADVISORY THRESHOLDS.

OUTLOOK...MONDAY THROUGH THURSDAY...MODERATE CONFIDENCE

MONDAY...EAST TO NORTHEAST WINDS GUSTING AROUND 15 KNOTS OR LESS.
SEAS WILL HOLD AROUND 3-4 FEET...MAY INCREASE TO 5FT IN NORTHEAST
FLOW AS GUIDANCE MAY BE UNDERDONE.

TUESDAY... INCREASING EAST WINDS WITH FREQUENT GUSTS 25 TO 30 KNOTS.
SEAS WILL BUILD TO 5-6 FEET ON THE EXPOSED WATERS.  A SMALL CRAFT
ADVISORY MAY BE NEEDED.

WEDNESDAY...RAIN WILL BE HEAVY AT TIMES PRODUCING POOR VISIBILITY.
INCREASING SOUTHEAST WINDS 20-25 SUSTAINED AND 40 KNOT GUSTS.  WINDS
SHOULD SHIFT TO SOUTH WEDNESDAY NIGHT AND SOUTHWEST TOWARD THURSDAY
MORNING. RAIN WILL TAPER OFF WITH THE WIND SHIFT TO SOUTHWEST. SEAS
WILL CONTINUE TO BUILD WITH 7-11 FEET HEIGHTS ON THE EXPOSED WATERS.
A GALE WARNING WILL BE NEEDED...WITH A LOW PROB OF A FEW STORM FORCE
GUSTS ACROSS THE EASTERN OUTER WATERS.

CHRISTMAS DAY... WEST SOUTHWEST WINDS WILL CONTINUE TO GUST 35-40
KNOTS...SO A CONTINUED GALE WARNING MAY BE NEEDED. SEAS OF 7-15 FEET
ARE POSSIBLE ON THE EXPOSED WATERS...AND 5 FEET IS POSSIBLE ON SOME
OF THE NEARSHORE WATERS.

&&

.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES WILL OCCUR TUESDAY THROUGH THURSDAY. BREAKING
IT DOWN...ON TUESDAY HIGH TIDE AT BOSTON WILL BE 11.6 FT. THERE WILL
BE ONSHORE FLOW DURING THIS HIGH TIDE ALLOWING FOR MINOR SPLASHOVER.
IF WIND GUSTS INCREASE THEN COULD POSSIBLE SEE MINOR COASTAL
FLOODING.

ON WEDNESDAY...WINDS WILL SWITCH TO A MORE SOUTHEASTERLY FLOW DURING
THE DAY AND INCREASE QUICKLY FROM APPROACHING SYSTEM AND DECENT
PRESSURE FALLS. WEDNESDAY AFTERNOON HIGH TIDE IN BOSTON IS 11.7 FT
AND WITH ANY STRENGTH ON THE EASTERLY WIND FLOW WILL PUSH THE TIDE
OVER. RIGHT NOW BELIEVE MINOR COASTAL FLOODING IS POSSIBLE ALONG THE
EAST COASTLINE.

WEDNESDAY EVENING...THE WIND GOES IN A MORE SOUTHERLY DIRECTION AND
THE TIDE WILL BE INCREASE ACROSS THE SOUTH COAST. HIGH TIDE IN
PROVIDENCE WILL BE 5.2 FT. 925 MB LLJ STRENGTHENS TO 50-60 KTS WHICH
COULD PUSH A DECENT SURGE UP ALONG THE SOUTH COAST DURING THE TIME
OF HIGH TIDE. THINKING THAT MINOR COASTAL FLOODING COULD OCCUR BUT
CANNOT RULE OUT MODERATE ALONG THE SOUTH COAST...ESP IF LLJ
STRENGTHENS EVEN MORE.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...FRANK/DUNTEN
NEAR TERM...RLG
SHORT TERM...FRANK
LONG TERM...DUNTEN
AVIATION...DUNTEN/RLG
MARINE...FRANK/DUNTEN
TIDES/COASTAL FLOODING...




000
FXUS61 KBOX 211452
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
952 AM EST SUN DEC 21 2014

.SYNOPSIS...
SCATTERED SNOW/RAIN SHOWERS CONTINUE THROUGH THIS AFTERNOON. WEAK
LOW PRESSURE WILL PASS SOUTH OF NEW ENGLAND BRINGING ANOTHER
PERIOD OF PRECIPITATION MONDAY NIGHT AND TUESDAY. A MUCH STRONGER
STORM PASSING WEST OF NEW ENGLAND WILL BRING HEAVY RAINFALL...
GUSTY WINDS AND COASTAL FLOODING CONCERNS TO THE REGION WEDNESDAY
AND WEDNESDAY NIGHT. DRY BUT VERY WINDY CONDITIONS FOLLOW FOR
CHRISTMAS DAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
10 AM UPDATE...SCATTERED SNOW SHOWERS CONTINUE ACROSS SOUTHERN NEW
ENGLAND THIS MORNING. MOST OF THESE ARE TOO LIGHT EVEN TO SHOW UP
ON RADAR BUT THEY ARE BEING REPORTED IN GROUND TRUTH REPORTS FROM
SOCIAL MEDIA AND THE PUBLIC.

PREVIOUS DISCUSSION...

THE RAIN/SNOW LINE RUNS ROUGHLY FROM NEWPORT...TO TAUNTON AND
JUST NORTH OF MARSHFIELD. OVERALL...DO NOT EXPECT MUCH CHANGE IN
THE RAIN/SNOW LINE THIS MORNING BASED ON THERMAL PROFILES AND
POSITIONING OF THE COASTAL FRONT.

MAIN UNCERTAINTY IS JUST HOW MUCH SNOW OCCURS THIS MORNING WITH THE
SHORTWAVE MOVING ACROSS CT.  GIVEN THE TRACK OF THE SHORTWAVE...BEST
FORCING WILL BE LOCATED SOUTH OF THE MA TURNPIKE AND ESPECIALLY
ACROSS NORTHERN CT/RI.  WE WILL FORECAST 1 TO 2 INCHES OF SNOW
ACROSS THIS REGION...BUT A FEW ISOLATED 3 INCH AMOUNTS CAN NOT BE
RULED OUT. MEANWHILE...AREAS NORTH OF THE MA TURNPIKE WILL BE
REMOVED FROM THE BEST FORCING...BUT STILL SEE SOME SCATTERED
SHOWERS.  ACCUMS IN THIS AREA LIKELY TO BE A DUSTING TO LESS THAN AN
INCH.

ALSO...SOME OF THE PRECIPITATION CURRENTLY ACROSS SOUTHEAST MA IS
BEING ENHANCED FROM THE COASTAL FRONT.  A LOT OF THIS PRECIP WILL
BE IN THE FORM OF RAIN SHOWERS ACROSS PLYMOUTH AND EVEN INTO
PORTIONS OF BRISTOL COUNTY...POINTS SOUTH AND EAST.  HOWEVER...AT
LEAST THE SLIGHTLY HIGHER TERRAIN OF SOUTHEAST MA SHOULD SEE SNOW
SHOWERS.  WILL HAVE TO KEEP A CLOSE EYE ON IF COASTAL FRONT SHIFTS
SLIGHTLY THIS MORNING.  IT COULD MEAN THE DIFFERENCE BETWEEN AN AREA
GETTING MAINLY RAIN SHOWERS OR PERHAPS AN INCH OR SO OF SNOW.
OVERALL...DO NOT EXPECT THE COASTAL FRONT TO MOVE TOO MUCH THIS
MORNING...BUT JUST A FEW MILES CAN MAKE DIFFERENCE FOR A
PARTICULARLY NEIGHBORHOOD.

BULK OF PRECIPITATION WILL BE THIS MORNING WITH THE SHORTWAVE.
HOWEVER...ENOUGH LOW LEVEL MOISTURE/WEAK LIFT WILL REMAIN THIS
AFTERNOON FOR AT LEAST THIS RISK OF SCATTERED PRECIPITATION AND WILL
MAINTAIN SOME POPS.  HIGH TEMPS MAINLY IN THE 30S.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
TONIGHT...

A RATHER CLOUDY AND RAW NIGHT ACROSS SOUTHERN NEW ENGLAND.  WHILE
THERE IS NOT A SIGNIFICANT SHORTWAVE TO TRIGGER A LOT OF
PRECIPITATION...PLENTY OF LOW LEVEL MOISTURE/WEAK SHALLOW LIFT
REMAINS.  THIS MAY BE ENOUGH TO RESULT IN A FEW RAIN/SNOW SHOWER
FROM TIME TO TIME.  PTYPE...WOULD BE MAINLY SNOW SHOWERS EXCEPT TO
THE SOUTHEAST OF A NEWPORT...TO TAUNTON...TO JUST NORTH OF
MARSHFIELD LINE.  AGAIN...MUCH OF THE NIGHT WILL PROBABLY END UP
DRY...BUT JUST THE RISK FOR A FEW RAIN/SNOW SHOWERS.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
HIGHLIGHTS...

* WEAK SHORTWAVE ON MON NIGHT/TUESDAY COULD BRING WINTRY
  MIX/FREEZING RAIN TO THE INTERIOR
* ANOMALOUS SYSTEM ACROSS THE GREAT LAKES WILL BRING HEAVY
  RAIN...GUSTY WINDS AND COASTAL FLOODING CONCERNS AROUND CHRISTMAS
  EVE
* BLUSTERY BUT AIRMASS WILL BE DRYING OUT ON CHRISTMAS DAY

OVERVIEW...

THE MODELS AND ENSEMBLES OFFER A REASONABLY SIMILAR AND PREDICTABLE
LARGER SCALE MID TO UPPER LEVEL PATTERN EVOLUTION FOR MUCH OF THE
UPCOMING WEEK. THIS ACTIVE FLOW REGIME DEVELOPS SEVERAL MID-UPPER
LEVEL TROUGH AND ASSOCIATED/UNSETTLING LEAD SURFACE LOW/FRONTAL
SYSTEMS AND PCPN SWATHS PROGRESS STEADILY ACROSS THE LOWER 48. THE
FIRST AMPLIFIED/DEEP LEAD SYSTEM WORKS ACROSS THE ERN/NERN US INTO
ERN CANADA CHRISTMAS EVE INTO CHRISTMAS ALLOWING FOR A MOIST/WARMED
AIRMASS IN ADVANCE OF FRONTAL APPROACH WITH HEAVIEST LEAD QPF
POTENTIAL OVER NEW ENGLAND. BIGGEST QUESTION IS THE EVOLUTION OF THE
SECONDARY LOW PRESSURE SYSTEM. 00Z GUIDANCE HAS BACKED OFF ON THE
STRENGTH OF THE LOW AND IS HAVING ISSUES ON HOW TO HANDLE ITS
EVOLUTION. THE EC AND GFS HAVE SLOWED DOWN THE SYSTEM SLIGHTLY WITH
THE EC HAVING MORE OF A NEGATIVE TROUGH VS THE GFS. BELIEVE THE
UKMET IS A GOOD COMPROMISE AT IS WAS THE FIRST DETERMINISTIC
GUIDANCE ON TAMPERING DOWN THE FIRST MAIN LOW...WHILE THE CMC IS OUT
TO LUNCH. REGARDLESS THIS IS A VERY ANOMALOUS SYSTEM THAT IS ABOUT 4
STANDARD DEVIATIONS AWAY.

A SECONDARY SYSTEM DEEPENS ACROSS THE FOUR CORNERS ON FRIDAY AND
WITH THE STUBBORN TROUGH OVER THE CENTRAL U.S...IT WILL PUSH A
SYSTEM TOWARDS SOUTHERN NEW ENGLAND BY SUNDAY. THIS SYSTEM MAY
SUPPORT A MODEST SWATH OF OVERRUNNING SNOW OVER SOUTHERN NEW
ENGLAND.

DETAILS...

MONDAY INTO TUESDAY...MODERATE CONFIDENCE.

A WEAK WAVE OF LOW PRESSURE DEVELOPS ALONG THE SOUTHEAST COAST
MONDAY...AND WILL BE ON A DEVELOPING WARM FRONTAL BOUNDARY. THIS LOW
REMAINS WEAK AS THE WARM FRONT MOVES SLOWLY NORTH MONDAY NIGHT INTO
TUESDAY. APPEARS THAT THERE IS DECENT WARM ADVECTION AHEAD OF THIS
WAVE. SEVERAL HI-RES GUIDANCE MODELS SHOW THAT THERE IS THE
POTENTIAL FOR COLD AIR DAMMING ACROSS THE INTERIOR INTO TUESDAY.
BIGGEST QUESTION WILL BE IS THERE ENOUGH MOISTURE FOR PRECIP DURING
THIS TIME FRAME. DUE TO A STRENGTHENING LLJ PROVIDING A GOOD SOURCE OF
LIFT ANTICIPATE PRECIP TO DEVELOP AND OVERSPREAD ACROSS SOUTHERN NEW
ENGLAND. IF THIS PLAYS OUT WITH COLD AIR DAMMING AND WARM AIR
ADVECTION...THEN WE COULD SEE FREEZING RAIN/DRIZZLE ACROSS THE I-91
CORRIDOR LATE MONDAY INTO TUESDAY MORNING. DURING THE DAY ON
TUESDAY...GOOD AMOUNT OF WARM AIR WILL PUSH SURFACE TEMPS ABOVE
FREEZING BY THE LATE MORNING ALLOWING FOR ANY PRECIP TO BE MORE OF
THE LIQUID VARIETY AHEAD OF THE CHRISTMAS EVE STORM. HOWEVER
GUIDANCE IS ALWAYS TOO FAST IN SCOURING TEMPS OUT ESP ACROSS THE CT
VALLEY SO WE WILL NEED TO MONITOR THIS CLOSELY...ESP DUE TO LIGHT
WINDS AND THE HIGH IN EASTERN CANADA. A WINTER WX ADVISORY MAY BE
NEEDED FOR THE LIGHT ICING POTENTIAL.

WE COULD ALSO SEE SOME MINOR COASTAL FLOODING CONCERNS ON TUESDAY. SEE
BELOW FOR MORE DETAILS.

WEDNESDAY INTO THURSDAY...HIGH CONFIDENCE IN SYSTEM LOW CONFIDENCE
ON DETAILS.

ANOMALOUS SYSTEM WILL STRENGTHEN OVER THE GREAT LAKES TUESDAY INTO
WEDNESDAY. A SECONDARY SHORTWAVE WILL ROUND THE DEEP TROUGH AND
DEVELOP A SECONDARY LOW PRESSURE ALONG THE COLD FRONT. THIS
SECONDARY LOW WILL STRENGTHEN AND PASS WEST OF SOUTHERN NEW ENGLAND.
THIS SYSTEM WILL CONTINUE TO DEEPEN AS IT MOVES TOWARDS EASTERN
CANADA SWINGING A COLD FRONT ACROSS THE NORTHEAST.

STRONG SOUTHERLY JET OUT AHEAD OF THE FRONT WITH A GULF MOISTURE
CONNECTION WILL IMPACT SOUTHERN NEW ENGLAND ON CHRISTMAS EVE. THIS
STRONG JET WILL YIELD FOR PCPN IN THE LIQUID VARIETY.  PW ANOMALIES
ARE BETWEEN +4 TO +5 STANDARD DEVIATIONS ABOVE NORMAL WHICH IS QUITE
ANOMALOUS FOR THIS TIME OF YEAR. IN FACT CURRENT PWATS ARE PROGGED
ABOVE 1.6 INCHES WITH MODEL QPF OVER 2 INCHES...AT THE VERY LEAST
COULD SEE URBAN AND POOR DRAINAGE FLOODING. LATEST EC EVEN SHOWS
OVER 2.5 INCHES OF QPF...AND WITH THE TROPICAL CONNECTION AND STRONG
SOUTHERLY FLOW COULD SEE HIGHER AMOUNTS DUE TO TOPOGRAPHY
ENHANCEMENTS. RAINFALL RECORDS MAY FALL IF EVERYTHING FALLS INTO
PLACE.

AHEAD OF THE FRONT...SOUTHERN NEW ENGLAND WILL WARM SECTOR WED INTO
THUR MORNING ALLOWING FOR TEMPERATURES TO BE WELL ABOVE AVERAGE. IN
FACT WE MAY BE CLOSE AT BREAKING RECORD HIGH TEMPS IF TEMPS WARM TO
60F OR ABOVE ON CHRISTMAS EVE. SINCE WE WILL BE IN THE WARM
SECTOR...AND SHOWALTERS CLOSE TO ZERO...ISOLATED THUNDER IS STILL
POSSIBLE.

STRONG LOW LEVEL WINDS WILL ALSO BE A CONCERN ESPECIALLY WEDNESDAY
NIGHT. THE ECMWF SHOWS EAST-SOUTHEAST WINDS 30-40 KNOTS ON WEDNESDAY
INCREASING TO 60-75 KNOTS BY WEDNESDAY NIGHT. STRONG DOWNPOURS MAY
OVERCOME THE LOW LEVEL INVERSION AND BRING STRONG GUSTS OF AT LEAST
30-40 KNOTS ESPECIALLY ALONG THE SOUTH COAST. A WIND ADVISORY MAY BE
NEEDED IN SOME AREAS.

CHRISTMAS DAY...MODERATE CONFIDENCE.

AS THE COLD FRONT PASSES THROUGH EARLY CHRISTMAS DAY...THE WEST
WINDS WILL HELP DRY THE AIRMASS ALLOWING FOR PARTLY SUNNY SKIES.
STRONG CAA ON THURSDAY WILL ALLOW DESCENT MIXING. WINDS IN THE SFC-
850 MB LAYER WILL BE 30-40 KNOTS AND POSSIBLY A LITTLE
HIGHER...WHICH WOULD REQUIRE A WIND ADVISORY FOR MUCH OF THE AREA.

FRIDAY-SUNDAY...LOWER CONFIDENCE

WEAK HIGH PRESSURE BUILDS OVER THE AREA FRIDAY INTO SATURDAY. THE
NEXT SHORTWAVE APPROACHES LATE SATURDAY INTO SUNDAY AND SHOULD BRING
INCREASING CLOUDS FROM WEST TO EAST ALONG WITH A CHANCE OF RAIN OR
SNOW SHOWERS MAINLY IN THE AFTERNOON AND AT NIGHT.

&&

.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/...

TODAY AND TONIGHT...MODERATE CONFIDENCE.  MAINLY MVFR CONDITIONS
SOUTH OF THE MA TURNPIKE WITH BORDERLINE VFR TO MARGINAL MVFR CIGS
NORTH OF THE PIKE THROUGH TONIGHT.  AN AREA OF SNOW SHOWERS WILL
EXPAND MAINLY ACROSS AREAS SOUTH OF THE PIKE THIS MORNING...BUT A
FEW SNOW SHOWERS WILL STILL AFFECT NORTHERN MA.  VSBYS/CIGS MAY
BRIEFLY DROP TO IFR LEVELS IN NORTHERN CT/RI/SE MA.  PTYPE WILL BE
RAIN SHOWERS ACROSS MOST OF PLYMOUTH COUNTY AND ONTO THE
CAPE/ISLANDS WITH SNOW SHOWERS NORTH AND WEST.  BULK OF PRECIP THIS
MORNING...BUT A FEW LINGERING RAIN/SNOW SHOWERS STILL POSSIBLE THIS
AFTERNOON AND EVENING.

KBOS TERMINAL...MODERATE CONFIDENCE.  A FEW SNOW SHOWERS POSSIBLE
THIS MORNING BUT BULK OF ACTIVITY SHOULD BE SOUTH OF THE TERMINAL.

KBDL TERMINAL...MODERATE CONFIDENCE.  PERIOD OF SNOW SHOWERS THIS
MORNING MAY DROP AN INCH OR TWO OF SNOW.  MVFR CONDITIONS DOMINATE
TODAY....BUT A BRIEF PERIOD OF IFR CONDITIONS ARE POSSIBLE THIS
MORNING IN SNOW SHOWERS.

OUTLOOK...MONDAY THROUGH THURSDAY...MODERATE CONFIDENCE.

MONDAY...MVFR CIGS CONTINUE IN RI/EASTERN MASS IN MARINE EAST FLOW.
VFR IN THE WEST.

TUESDAY...VFR WITH SCATTERED MVFR IN ANY RAIN/SNOW SHOWERS.

WEDNESDAY...CONDITIONS LOWERING TO IFR IN RAIN/HEAVY RAIN. ISOLATED
THUNDERSTORMS POSSIBLE ESPECIALLY WEDNESDAY NIGHT. EAST-SOUTHEAST
SURFACE WINDS MAY GUST TO 35-45 KNOTS. WINDS AT 2000 FEET AGL WILL
REACH 50-60 KNOTS WEDNESDAY AFTERNOON AND EARLY NIGHT CREATING LOW
LEVEL WIND SHEAR CONCERNS.

CHRISTMAS DAY...WEST WIND GUSTING 30-40 KNOTS. CONDITIONS IMPROVING
TO VFR AS THE WIND BRINGS IN COOLER DRIER AIR.

&&

.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.

HIGH PRESSURE ACROSS QUEBEC WILL RESULT IN NORTHEAST WINDS ACROSS
THE WATERS THAT WILL GUST TO BETWEEN 15 AND 20 KNOTS.  THIS WILL
RESULT IN 2 TO 4 FOOT SEAS.  HOWEVER...NO HEADLINES PLANNED AS
CONDITIONS SHOULD REMAIN BELOW SMALL CRAFT ADVISORY THRESHOLDS.

OUTLOOK...MONDAY THROUGH THURSDAY...MODERATE CONFIDENCE

MONDAY...EAST TO NORTHEAST WINDS GUSTING AROUND 15 KNOTS OR LESS.
SEAS WILL HOLD AROUND 3-4 FEET...MAY INCREASE TO 5FT IN NORTHEAST
FLOW AS GUIDANCE MAY BE UNDERDONE.

TUESDAY... INCREASING EAST WINDS WITH FREQUENT GUSTS 25 TO 30 KNOTS.
SEAS WILL BUILD TO 5-6 FEET ON THE EXPOSED WATERS.  A SMALL CRAFT
ADVISORY MAY BE NEEDED.

WEDNESDAY...RAIN WILL BE HEAVY AT TIMES PRODUCING POOR VISIBILITY.
INCREASING SOUTHEAST WINDS 20-25 SUSTAINED AND 40 KNOT GUSTS.  WINDS
SHOULD SHIFT TO SOUTH WEDNESDAY NIGHT AND SOUTHWEST TOWARD THURSDAY
MORNING. RAIN WILL TAPER OFF WITH THE WIND SHIFT TO SOUTHWEST. SEAS
WILL CONTINUE TO BUILD WITH 7-11 FEET HEIGHTS ON THE EXPOSED WATERS.
A GALE WARNING WILL BE NEEDED...WITH A LOW PROB OF A FEW STORM FORCE
GUSTS ACROSS THE EASTERN OUTER WATERS.

CHRISTMAS DAY... WEST SOUTHWEST WINDS WILL CONTINUE TO GUST 35-40
KNOTS...SO A CONTINUED GALE WARNING MAY BE NEEDED. SEAS OF 7-15 FEET
ARE POSSIBLE ON THE EXPOSED WATERS...AND 5 FEET IS POSSIBLE ON SOME
OF THE NEARSHORE WATERS.

&&

.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES WILL OCCUR TUESDAY THROUGH THURSDAY. BREAKING
IT DOWN...ON TUESDAY HIGH TIDE AT BOSTON WILL BE 11.6 FT. THERE WILL
BE ONSHORE FLOW DURING THIS HIGH TIDE ALLOWING FOR MINOR SPLASHOVER.
IF WIND GUSTS INCREASE THEN COULD POSSIBLE SEE MINOR COASTAL
FLOODING.

ON WEDNESDAY...WINDS WILL SWITCH TO A MORE SOUTHEASTERLY FLOW DURING
THE DAY AND INCREASE QUICKLY FROM APPROACHING SYSTEM AND DECENT
PRESSURE FALLS. WEDNESDAY AFTERNOON HIGH TIDE IN BOSTON IS 11.7 FT
AND WITH ANY STRENGTH ON THE EASTERLY WIND FLOW WILL PUSH THE TIDE
OVER. RIGHT NOW BELIEVE MINOR COASTAL FLOODING IS POSSIBLE ALONG THE
EAST COASTLINE.

WEDNESDAY EVENING...THE WIND GOES IN A MORE SOUTHERLY DIRECTION AND
THE TIDE WILL BE INCREASE ACROSS THE SOUTH COAST. HIGH TIDE IN
PROVIDENCE WILL BE 5.2 FT. 925 MB LLJ STRENGTHENS TO 50-60 KTS WHICH
COULD PUSH A DECENT SURGE UP ALONG THE SOUTH COAST DURING THE TIME
OF HIGH TIDE. THINKING THAT MINOR COASTAL FLOODING COULD OCCUR BUT
CANNOT RULE OUT MODERATE ALONG THE SOUTH COAST...ESP IF LLJ
STRENGTHENS EVEN MORE.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...FRANK/DUNTEN
NEAR TERM...FRANK/DUNTEN/RLG
SHORT TERM...FRANK
LONG TERM...DUNTEN
AVIATION...FRANK/DUNTEN
MARINE...FRANK/DUNTEN
TIDES/COASTAL FLOODING...




000
FXUS61 KBOX 211452
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
952 AM EST SUN DEC 21 2014

.SYNOPSIS...
SCATTERED SNOW/RAIN SHOWERS CONTINUE THROUGH THIS AFTERNOON. WEAK
LOW PRESSURE WILL PASS SOUTH OF NEW ENGLAND BRINGING ANOTHER
PERIOD OF PRECIPITATION MONDAY NIGHT AND TUESDAY. A MUCH STRONGER
STORM PASSING WEST OF NEW ENGLAND WILL BRING HEAVY RAINFALL...
GUSTY WINDS AND COASTAL FLOODING CONCERNS TO THE REGION WEDNESDAY
AND WEDNESDAY NIGHT. DRY BUT VERY WINDY CONDITIONS FOLLOW FOR
CHRISTMAS DAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
10 AM UPDATE...SCATTERED SNOW SHOWERS CONTINUE ACROSS SOUTHERN NEW
ENGLAND THIS MORNING. MOST OF THESE ARE TOO LIGHT EVEN TO SHOW UP
ON RADAR BUT THEY ARE BEING REPORTED IN GROUND TRUTH REPORTS FROM
SOCIAL MEDIA AND THE PUBLIC.

PREVIOUS DISCUSSION...

THE RAIN/SNOW LINE RUNS ROUGHLY FROM NEWPORT...TO TAUNTON AND
JUST NORTH OF MARSHFIELD. OVERALL...DO NOT EXPECT MUCH CHANGE IN
THE RAIN/SNOW LINE THIS MORNING BASED ON THERMAL PROFILES AND
POSITIONING OF THE COASTAL FRONT.

MAIN UNCERTAINTY IS JUST HOW MUCH SNOW OCCURS THIS MORNING WITH THE
SHORTWAVE MOVING ACROSS CT.  GIVEN THE TRACK OF THE SHORTWAVE...BEST
FORCING WILL BE LOCATED SOUTH OF THE MA TURNPIKE AND ESPECIALLY
ACROSS NORTHERN CT/RI.  WE WILL FORECAST 1 TO 2 INCHES OF SNOW
ACROSS THIS REGION...BUT A FEW ISOLATED 3 INCH AMOUNTS CAN NOT BE
RULED OUT. MEANWHILE...AREAS NORTH OF THE MA TURNPIKE WILL BE
REMOVED FROM THE BEST FORCING...BUT STILL SEE SOME SCATTERED
SHOWERS.  ACCUMS IN THIS AREA LIKELY TO BE A DUSTING TO LESS THAN AN
INCH.

ALSO...SOME OF THE PRECIPITATION CURRENTLY ACROSS SOUTHEAST MA IS
BEING ENHANCED FROM THE COASTAL FRONT.  A LOT OF THIS PRECIP WILL
BE IN THE FORM OF RAIN SHOWERS ACROSS PLYMOUTH AND EVEN INTO
PORTIONS OF BRISTOL COUNTY...POINTS SOUTH AND EAST.  HOWEVER...AT
LEAST THE SLIGHTLY HIGHER TERRAIN OF SOUTHEAST MA SHOULD SEE SNOW
SHOWERS.  WILL HAVE TO KEEP A CLOSE EYE ON IF COASTAL FRONT SHIFTS
SLIGHTLY THIS MORNING.  IT COULD MEAN THE DIFFERENCE BETWEEN AN AREA
GETTING MAINLY RAIN SHOWERS OR PERHAPS AN INCH OR SO OF SNOW.
OVERALL...DO NOT EXPECT THE COASTAL FRONT TO MOVE TOO MUCH THIS
MORNING...BUT JUST A FEW MILES CAN MAKE DIFFERENCE FOR A
PARTICULARLY NEIGHBORHOOD.

BULK OF PRECIPITATION WILL BE THIS MORNING WITH THE SHORTWAVE.
HOWEVER...ENOUGH LOW LEVEL MOISTURE/WEAK LIFT WILL REMAIN THIS
AFTERNOON FOR AT LEAST THIS RISK OF SCATTERED PRECIPITATION AND WILL
MAINTAIN SOME POPS.  HIGH TEMPS MAINLY IN THE 30S.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
TONIGHT...

A RATHER CLOUDY AND RAW NIGHT ACROSS SOUTHERN NEW ENGLAND.  WHILE
THERE IS NOT A SIGNIFICANT SHORTWAVE TO TRIGGER A LOT OF
PRECIPITATION...PLENTY OF LOW LEVEL MOISTURE/WEAK SHALLOW LIFT
REMAINS.  THIS MAY BE ENOUGH TO RESULT IN A FEW RAIN/SNOW SHOWER
FROM TIME TO TIME.  PTYPE...WOULD BE MAINLY SNOW SHOWERS EXCEPT TO
THE SOUTHEAST OF A NEWPORT...TO TAUNTON...TO JUST NORTH OF
MARSHFIELD LINE.  AGAIN...MUCH OF THE NIGHT WILL PROBABLY END UP
DRY...BUT JUST THE RISK FOR A FEW RAIN/SNOW SHOWERS.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
HIGHLIGHTS...

* WEAK SHORTWAVE ON MON NIGHT/TUESDAY COULD BRING WINTRY
  MIX/FREEZING RAIN TO THE INTERIOR
* ANOMALOUS SYSTEM ACROSS THE GREAT LAKES WILL BRING HEAVY
  RAIN...GUSTY WINDS AND COASTAL FLOODING CONCERNS AROUND CHRISTMAS
  EVE
* BLUSTERY BUT AIRMASS WILL BE DRYING OUT ON CHRISTMAS DAY

OVERVIEW...

THE MODELS AND ENSEMBLES OFFER A REASONABLY SIMILAR AND PREDICTABLE
LARGER SCALE MID TO UPPER LEVEL PATTERN EVOLUTION FOR MUCH OF THE
UPCOMING WEEK. THIS ACTIVE FLOW REGIME DEVELOPS SEVERAL MID-UPPER
LEVEL TROUGH AND ASSOCIATED/UNSETTLING LEAD SURFACE LOW/FRONTAL
SYSTEMS AND PCPN SWATHS PROGRESS STEADILY ACROSS THE LOWER 48. THE
FIRST AMPLIFIED/DEEP LEAD SYSTEM WORKS ACROSS THE ERN/NERN US INTO
ERN CANADA CHRISTMAS EVE INTO CHRISTMAS ALLOWING FOR A MOIST/WARMED
AIRMASS IN ADVANCE OF FRONTAL APPROACH WITH HEAVIEST LEAD QPF
POTENTIAL OVER NEW ENGLAND. BIGGEST QUESTION IS THE EVOLUTION OF THE
SECONDARY LOW PRESSURE SYSTEM. 00Z GUIDANCE HAS BACKED OFF ON THE
STRENGTH OF THE LOW AND IS HAVING ISSUES ON HOW TO HANDLE ITS
EVOLUTION. THE EC AND GFS HAVE SLOWED DOWN THE SYSTEM SLIGHTLY WITH
THE EC HAVING MORE OF A NEGATIVE TROUGH VS THE GFS. BELIEVE THE
UKMET IS A GOOD COMPROMISE AT IS WAS THE FIRST DETERMINISTIC
GUIDANCE ON TAMPERING DOWN THE FIRST MAIN LOW...WHILE THE CMC IS OUT
TO LUNCH. REGARDLESS THIS IS A VERY ANOMALOUS SYSTEM THAT IS ABOUT 4
STANDARD DEVIATIONS AWAY.

A SECONDARY SYSTEM DEEPENS ACROSS THE FOUR CORNERS ON FRIDAY AND
WITH THE STUBBORN TROUGH OVER THE CENTRAL U.S...IT WILL PUSH A
SYSTEM TOWARDS SOUTHERN NEW ENGLAND BY SUNDAY. THIS SYSTEM MAY
SUPPORT A MODEST SWATH OF OVERRUNNING SNOW OVER SOUTHERN NEW
ENGLAND.

DETAILS...

MONDAY INTO TUESDAY...MODERATE CONFIDENCE.

A WEAK WAVE OF LOW PRESSURE DEVELOPS ALONG THE SOUTHEAST COAST
MONDAY...AND WILL BE ON A DEVELOPING WARM FRONTAL BOUNDARY. THIS LOW
REMAINS WEAK AS THE WARM FRONT MOVES SLOWLY NORTH MONDAY NIGHT INTO
TUESDAY. APPEARS THAT THERE IS DECENT WARM ADVECTION AHEAD OF THIS
WAVE. SEVERAL HI-RES GUIDANCE MODELS SHOW THAT THERE IS THE
POTENTIAL FOR COLD AIR DAMMING ACROSS THE INTERIOR INTO TUESDAY.
BIGGEST QUESTION WILL BE IS THERE ENOUGH MOISTURE FOR PRECIP DURING
THIS TIME FRAME. DUE TO A STRENGTHENING LLJ PROVIDING A GOOD SOURCE OF
LIFT ANTICIPATE PRECIP TO DEVELOP AND OVERSPREAD ACROSS SOUTHERN NEW
ENGLAND. IF THIS PLAYS OUT WITH COLD AIR DAMMING AND WARM AIR
ADVECTION...THEN WE COULD SEE FREEZING RAIN/DRIZZLE ACROSS THE I-91
CORRIDOR LATE MONDAY INTO TUESDAY MORNING. DURING THE DAY ON
TUESDAY...GOOD AMOUNT OF WARM AIR WILL PUSH SURFACE TEMPS ABOVE
FREEZING BY THE LATE MORNING ALLOWING FOR ANY PRECIP TO BE MORE OF
THE LIQUID VARIETY AHEAD OF THE CHRISTMAS EVE STORM. HOWEVER
GUIDANCE IS ALWAYS TOO FAST IN SCOURING TEMPS OUT ESP ACROSS THE CT
VALLEY SO WE WILL NEED TO MONITOR THIS CLOSELY...ESP DUE TO LIGHT
WINDS AND THE HIGH IN EASTERN CANADA. A WINTER WX ADVISORY MAY BE
NEEDED FOR THE LIGHT ICING POTENTIAL.

WE COULD ALSO SEE SOME MINOR COASTAL FLOODING CONCERNS ON TUESDAY. SEE
BELOW FOR MORE DETAILS.

WEDNESDAY INTO THURSDAY...HIGH CONFIDENCE IN SYSTEM LOW CONFIDENCE
ON DETAILS.

ANOMALOUS SYSTEM WILL STRENGTHEN OVER THE GREAT LAKES TUESDAY INTO
WEDNESDAY. A SECONDARY SHORTWAVE WILL ROUND THE DEEP TROUGH AND
DEVELOP A SECONDARY LOW PRESSURE ALONG THE COLD FRONT. THIS
SECONDARY LOW WILL STRENGTHEN AND PASS WEST OF SOUTHERN NEW ENGLAND.
THIS SYSTEM WILL CONTINUE TO DEEPEN AS IT MOVES TOWARDS EASTERN
CANADA SWINGING A COLD FRONT ACROSS THE NORTHEAST.

STRONG SOUTHERLY JET OUT AHEAD OF THE FRONT WITH A GULF MOISTURE
CONNECTION WILL IMPACT SOUTHERN NEW ENGLAND ON CHRISTMAS EVE. THIS
STRONG JET WILL YIELD FOR PCPN IN THE LIQUID VARIETY.  PW ANOMALIES
ARE BETWEEN +4 TO +5 STANDARD DEVIATIONS ABOVE NORMAL WHICH IS QUITE
ANOMALOUS FOR THIS TIME OF YEAR. IN FACT CURRENT PWATS ARE PROGGED
ABOVE 1.6 INCHES WITH MODEL QPF OVER 2 INCHES...AT THE VERY LEAST
COULD SEE URBAN AND POOR DRAINAGE FLOODING. LATEST EC EVEN SHOWS
OVER 2.5 INCHES OF QPF...AND WITH THE TROPICAL CONNECTION AND STRONG
SOUTHERLY FLOW COULD SEE HIGHER AMOUNTS DUE TO TOPOGRAPHY
ENHANCEMENTS. RAINFALL RECORDS MAY FALL IF EVERYTHING FALLS INTO
PLACE.

AHEAD OF THE FRONT...SOUTHERN NEW ENGLAND WILL WARM SECTOR WED INTO
THUR MORNING ALLOWING FOR TEMPERATURES TO BE WELL ABOVE AVERAGE. IN
FACT WE MAY BE CLOSE AT BREAKING RECORD HIGH TEMPS IF TEMPS WARM TO
60F OR ABOVE ON CHRISTMAS EVE. SINCE WE WILL BE IN THE WARM
SECTOR...AND SHOWALTERS CLOSE TO ZERO...ISOLATED THUNDER IS STILL
POSSIBLE.

STRONG LOW LEVEL WINDS WILL ALSO BE A CONCERN ESPECIALLY WEDNESDAY
NIGHT. THE ECMWF SHOWS EAST-SOUTHEAST WINDS 30-40 KNOTS ON WEDNESDAY
INCREASING TO 60-75 KNOTS BY WEDNESDAY NIGHT. STRONG DOWNPOURS MAY
OVERCOME THE LOW LEVEL INVERSION AND BRING STRONG GUSTS OF AT LEAST
30-40 KNOTS ESPECIALLY ALONG THE SOUTH COAST. A WIND ADVISORY MAY BE
NEEDED IN SOME AREAS.

CHRISTMAS DAY...MODERATE CONFIDENCE.

AS THE COLD FRONT PASSES THROUGH EARLY CHRISTMAS DAY...THE WEST
WINDS WILL HELP DRY THE AIRMASS ALLOWING FOR PARTLY SUNNY SKIES.
STRONG CAA ON THURSDAY WILL ALLOW DESCENT MIXING. WINDS IN THE SFC-
850 MB LAYER WILL BE 30-40 KNOTS AND POSSIBLY A LITTLE
HIGHER...WHICH WOULD REQUIRE A WIND ADVISORY FOR MUCH OF THE AREA.

FRIDAY-SUNDAY...LOWER CONFIDENCE

WEAK HIGH PRESSURE BUILDS OVER THE AREA FRIDAY INTO SATURDAY. THE
NEXT SHORTWAVE APPROACHES LATE SATURDAY INTO SUNDAY AND SHOULD BRING
INCREASING CLOUDS FROM WEST TO EAST ALONG WITH A CHANCE OF RAIN OR
SNOW SHOWERS MAINLY IN THE AFTERNOON AND AT NIGHT.

&&

.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/...

TODAY AND TONIGHT...MODERATE CONFIDENCE.  MAINLY MVFR CONDITIONS
SOUTH OF THE MA TURNPIKE WITH BORDERLINE VFR TO MARGINAL MVFR CIGS
NORTH OF THE PIKE THROUGH TONIGHT.  AN AREA OF SNOW SHOWERS WILL
EXPAND MAINLY ACROSS AREAS SOUTH OF THE PIKE THIS MORNING...BUT A
FEW SNOW SHOWERS WILL STILL AFFECT NORTHERN MA.  VSBYS/CIGS MAY
BRIEFLY DROP TO IFR LEVELS IN NORTHERN CT/RI/SE MA.  PTYPE WILL BE
RAIN SHOWERS ACROSS MOST OF PLYMOUTH COUNTY AND ONTO THE
CAPE/ISLANDS WITH SNOW SHOWERS NORTH AND WEST.  BULK OF PRECIP THIS
MORNING...BUT A FEW LINGERING RAIN/SNOW SHOWERS STILL POSSIBLE THIS
AFTERNOON AND EVENING.

KBOS TERMINAL...MODERATE CONFIDENCE.  A FEW SNOW SHOWERS POSSIBLE
THIS MORNING BUT BULK OF ACTIVITY SHOULD BE SOUTH OF THE TERMINAL.

KBDL TERMINAL...MODERATE CONFIDENCE.  PERIOD OF SNOW SHOWERS THIS
MORNING MAY DROP AN INCH OR TWO OF SNOW.  MVFR CONDITIONS DOMINATE
TODAY....BUT A BRIEF PERIOD OF IFR CONDITIONS ARE POSSIBLE THIS
MORNING IN SNOW SHOWERS.

OUTLOOK...MONDAY THROUGH THURSDAY...MODERATE CONFIDENCE.

MONDAY...MVFR CIGS CONTINUE IN RI/EASTERN MASS IN MARINE EAST FLOW.
VFR IN THE WEST.

TUESDAY...VFR WITH SCATTERED MVFR IN ANY RAIN/SNOW SHOWERS.

WEDNESDAY...CONDITIONS LOWERING TO IFR IN RAIN/HEAVY RAIN. ISOLATED
THUNDERSTORMS POSSIBLE ESPECIALLY WEDNESDAY NIGHT. EAST-SOUTHEAST
SURFACE WINDS MAY GUST TO 35-45 KNOTS. WINDS AT 2000 FEET AGL WILL
REACH 50-60 KNOTS WEDNESDAY AFTERNOON AND EARLY NIGHT CREATING LOW
LEVEL WIND SHEAR CONCERNS.

CHRISTMAS DAY...WEST WIND GUSTING 30-40 KNOTS. CONDITIONS IMPROVING
TO VFR AS THE WIND BRINGS IN COOLER DRIER AIR.

&&

.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.

HIGH PRESSURE ACROSS QUEBEC WILL RESULT IN NORTHEAST WINDS ACROSS
THE WATERS THAT WILL GUST TO BETWEEN 15 AND 20 KNOTS.  THIS WILL
RESULT IN 2 TO 4 FOOT SEAS.  HOWEVER...NO HEADLINES PLANNED AS
CONDITIONS SHOULD REMAIN BELOW SMALL CRAFT ADVISORY THRESHOLDS.

OUTLOOK...MONDAY THROUGH THURSDAY...MODERATE CONFIDENCE

MONDAY...EAST TO NORTHEAST WINDS GUSTING AROUND 15 KNOTS OR LESS.
SEAS WILL HOLD AROUND 3-4 FEET...MAY INCREASE TO 5FT IN NORTHEAST
FLOW AS GUIDANCE MAY BE UNDERDONE.

TUESDAY... INCREASING EAST WINDS WITH FREQUENT GUSTS 25 TO 30 KNOTS.
SEAS WILL BUILD TO 5-6 FEET ON THE EXPOSED WATERS.  A SMALL CRAFT
ADVISORY MAY BE NEEDED.

WEDNESDAY...RAIN WILL BE HEAVY AT TIMES PRODUCING POOR VISIBILITY.
INCREASING SOUTHEAST WINDS 20-25 SUSTAINED AND 40 KNOT GUSTS.  WINDS
SHOULD SHIFT TO SOUTH WEDNESDAY NIGHT AND SOUTHWEST TOWARD THURSDAY
MORNING. RAIN WILL TAPER OFF WITH THE WIND SHIFT TO SOUTHWEST. SEAS
WILL CONTINUE TO BUILD WITH 7-11 FEET HEIGHTS ON THE EXPOSED WATERS.
A GALE WARNING WILL BE NEEDED...WITH A LOW PROB OF A FEW STORM FORCE
GUSTS ACROSS THE EASTERN OUTER WATERS.

CHRISTMAS DAY... WEST SOUTHWEST WINDS WILL CONTINUE TO GUST 35-40
KNOTS...SO A CONTINUED GALE WARNING MAY BE NEEDED. SEAS OF 7-15 FEET
ARE POSSIBLE ON THE EXPOSED WATERS...AND 5 FEET IS POSSIBLE ON SOME
OF THE NEARSHORE WATERS.

&&

.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES WILL OCCUR TUESDAY THROUGH THURSDAY. BREAKING
IT DOWN...ON TUESDAY HIGH TIDE AT BOSTON WILL BE 11.6 FT. THERE WILL
BE ONSHORE FLOW DURING THIS HIGH TIDE ALLOWING FOR MINOR SPLASHOVER.
IF WIND GUSTS INCREASE THEN COULD POSSIBLE SEE MINOR COASTAL
FLOODING.

ON WEDNESDAY...WINDS WILL SWITCH TO A MORE SOUTHEASTERLY FLOW DURING
THE DAY AND INCREASE QUICKLY FROM APPROACHING SYSTEM AND DECENT
PRESSURE FALLS. WEDNESDAY AFTERNOON HIGH TIDE IN BOSTON IS 11.7 FT
AND WITH ANY STRENGTH ON THE EASTERLY WIND FLOW WILL PUSH THE TIDE
OVER. RIGHT NOW BELIEVE MINOR COASTAL FLOODING IS POSSIBLE ALONG THE
EAST COASTLINE.

WEDNESDAY EVENING...THE WIND GOES IN A MORE SOUTHERLY DIRECTION AND
THE TIDE WILL BE INCREASE ACROSS THE SOUTH COAST. HIGH TIDE IN
PROVIDENCE WILL BE 5.2 FT. 925 MB LLJ STRENGTHENS TO 50-60 KTS WHICH
COULD PUSH A DECENT SURGE UP ALONG THE SOUTH COAST DURING THE TIME
OF HIGH TIDE. THINKING THAT MINOR COASTAL FLOODING COULD OCCUR BUT
CANNOT RULE OUT MODERATE ALONG THE SOUTH COAST...ESP IF LLJ
STRENGTHENS EVEN MORE.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...FRANK/DUNTEN
NEAR TERM...FRANK/DUNTEN/RLG
SHORT TERM...FRANK
LONG TERM...DUNTEN
AVIATION...FRANK/DUNTEN
MARINE...FRANK/DUNTEN
TIDES/COASTAL FLOODING...





000
FXUS61 KBOX 211154
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
654 AM EST SUN DEC 21 2014

.SYNOPSIS...
AN AREA OF SNOW SHOWERS WILL AFFECT AREAS MAINLY SOUTH OF THE MA
TURNPIKE THIS MORNING...EXCEPT IT WILL BE MILD ENOUGH FOR RAIN
SHOWERS ACROSS THE FAR SOUTHEAST NEW ENGLAND COAST. WEAK LOW
PRESSURE WILL PASS SOUTH OF NEW ENGLAND BRINGING ANOTHER PERIOD OF
PRECIPITATION MONDAY NIGHT AND TUESDAY. A MUCH STRONGER STORM
PASSING WEST OF NEW ENGLAND WILL BRING HEAVY RAINFALL...GUSTY
WINDS AND COASTAL FLOODING CONCERNS TO THE REGION WEDNESDAY AND
WEDNESDAY NIGHT. DRY BUT VERY WINDY CONDITIONS FOLLOW FOR
CHRISTMAS DAY.

&&

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

700 PM UPDATE...

VERY LITTLE CHANGES TO THE FORECAST AS OVERALL TREND IS ON TRACK
FOR THIS MORNING. RADAR ECHOES LOOK A LITTLE DECEIVING AS SNOW HAS
SPREAD ACROSS A GOOD PORTION OF SOUTHERN NEW ENGLAND PER OBS.
ANTICIPATE MORE WIDE SPREAD BUT LIGHT SNOW OVER THE NEXT HOUR OR
TWO OUTSIDE OF THE COASTAL FRONT...WHICH IS DRAPED OVER GHG-TAN-
UUU.

PREVIOUS DISCUSSION...

APPROACHING SHORTWAVE HAS ALLOWED AN AREA LIGHT SNOW SHOWERS TO
EXPAND SOUTH OF THE MA TURNPIKE VERY EARLY THIS MORNING...BUT A FEW
SNOW SHOWERS DID EXTEND INTO NORTHERN MA.  RADAR IMAGERY ACTUALLY
OVER SHOOTING SOME OF THE ACTIVITY ACROSS NORTHERN CT...BASED ON
OBSERVATIONS.  THE RAIN/SNOW LINE RUNS ROUGHLY FROM NEWPORT...TO
TAUNTON AND JUST NORTH OF MARSHFIELD.  OVERALL...DO NOT EXPECT MUCH
CHANGE IN THE RAIN/SNOW LINE THIS MORNING BASED ON THERMAL PROFILES
AND POSITIONING OF THE COASTAL FRONT.

MAIN UNCERTAINTY IS JUST HOW MUCH SNOW OCCURS THIS MORNING WITH THE
SHORTWAVE MOVING ACROSS CT.  GIVEN THE TRACK OF THE SHORTWAVE...BEST
FORCING WILL BE LOCATED SOUTH OF THE MA TURNPIKE AND ESPECIALLY
ACROSS NORTHERN CT/RI.  WE WILL FORECAST 1 TO 2 INCHES OF SNOW
ACROSS THIS REGION...BUT A FEW ISOLATED 3 INCH AMOUNTS CAN NOT BE
RULED OUT. MEANWHILE...AREAS NORTH OF THE MA TURNPIKE WILL BE
REMOVED FROM THE BEST FORCING...BUT STILL SEE SOME SCATTERED
SHOWERS.  ACCUMS IN THIS AREA LIKELY TO BE A DUSTING TO LESS THAN AN
INCH.

ALSO...SOME OF THE PRECIPITATION CURRENTLY ACROSS SOUTHEAST MA IS
BEING ENHANCED FROM THE COASTAL FRONT.  A LOT OF THIS PRECIP WILL
BE IN THE FORM OF RAIN SHOWERS ACROSS PLYMOUTH AND EVEN INTO
PORTIONS OF BRISTOL COUNTY...POINTS SOUTH AND EAST.  HOWEVER...AT
LEAST THE SLIGHTLY HIGHER TERRAIN OF SOUTHEAST MA SHOULD SEE SNOW
SHOWERS.  WILL HAVE TO KEEP A CLOSE EYE ON IF COASTAL FRONT SHIFTS
SLIGHTLY THIS MORNING.  IT COULD MEAN THE DIFFERENCE BETWEEN AN AREA
GETTING MAINLY RAIN SHOWERS OR PERHAPS AN INCH OR SO OF SNOW.
OVERALL...DO NOT EXPECT THE COASTAL FRONT TO MOVE TOO MUCH THIS
MORNING...BUT JUST A FEW MILES CAN MAKE DIFFERENCE FOR A
PARTICULARLY NEIGHBORHOOD.

BULK OF PRECIPITATION WILL BE THIS MORNING WITH THE SHORTWAVE.
HOWEVER...ENOUGH LOW LEVEL MOISTURE/WEAK LIFT WILL REMAIN THIS
AFTERNOON FOR AT LEAST THIS RISK OF SCATTERED PRECIPITATION AND WILL
MAINTAIN SOME POPS.  HIGH TEMPS MAINLY IN THE 30S.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
TONIGHT...

A RATHER CLOUDY AND RAW NIGHT ACROSS SOUTHERN NEW ENGLAND.  WHILE
THERE IS NOT A SIGNIFICANT SHORTWAVE TO TRIGGER A LOT OF
PRECIPITATION...PLENTY OF LOW LEVEL MOISTURE/WEAK SHALLOW LIFT
REMAINS.  THIS MAY BE ENOUGH TO RESULT IN A FEW RAIN/SNOW SHOWER
FROM TIME TO TIME.  PTYPE...WOULD BE MAINLY SNOW SHOWERS EXCEPT TO
THE SOUTHEAST OF A NEWPORT...TO TAUNTON...TO JUST NORTH OF
MARSHFIELD LINE.  AGAIN...MUCH OF THE NIGHT WILL PROBABLY END UP
DRY...BUT JUST THE RISK FOR A FEW RAIN/SNOW SHOWERS.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
HIGHLIGHTS...

* WEAK SHORTWAVE ON MON NIGHT/TUESDAY COULD BRING WINTRY
  MIX/FREEZING RAIN TO THE INTERIOR
* ANOMALOUS SYSTEM ACROSS THE GREAT LAKES WILL BRING HEAVY
  RAIN...GUSTY WINDS AND COASTAL FLOODING CONCERNS AROUND CHRISTMAS
  EVE
* BLUSTERY BUT AIRMASS WILL BE DRYING OUT ON CHRISTMAS DAY

OVERVIEW...

THE MODELS AND ENSEMBLES OFFER A REASONABLY SIMILAR AND PREDICTABLE
LARGER SCALE MID TO UPPER LEVEL PATTERN EVOLUTION FOR MUCH OF THE
UPCOMING WEEK. THIS ACTIVE FLOW REGIME DEVELOPS SEVERAL MID-UPPER
LEVEL TROUGH AND ASSOCIATED/UNSETTLING LEAD SURFACE LOW/FRONTAL
SYSTEMS AND PCPN SWATHS PROGRESS STEADILY ACROSS THE LOWER 48. THE
FIRST AMPLIFIED/DEEP LEAD SYSTEM WORKS ACROSS THE ERN/NERN US INTO
ERN CANADA CHRISTMAS EVE INTO CHRISTMAS ALLOWING FOR A MOIST/WARMED
AIRMASS IN ADVANCE OF FRONTAL APPROACH WITH HEAVIEST LEAD QPF
POTENTIAL OVER NEW ENGLAND. BIGGEST QUESTION IS THE EVOLUTION OF THE
SECONDARY LOW PRESSURE SYSTEM. 00Z GUIDANCE HAS BACKED OFF ON THE
STRENGTH OF THE LOW AND IS HAVING ISSUES ON HOW TO HANDLE ITS
EVOLUTION. THE EC AND GFS HAVE SLOWED DOWN THE SYSTEM SLIGHTLY WITH
THE EC HAVING MORE OF A NEGATIVE TROUGH VS THE GFS. BELIEVE THE
UKMET IS A GOOD COMPROMISE AT IS WAS THE FIRST DETERMINISTIC
GUIDANCE ON TAMPERING DOWN THE FIRST MAIN LOW...WHILE THE CMC IS OUT
TO LUNCH. REGARDLESS THIS IS A VERY ANOMALOUS SYSTEM THAT IS ABOUT 4
STANDARD DEVIATIONS AWAY.

A SECONDARY SYSTEM DEEPENS ACROSS THE FOUR CORNERS ON FRIDAY AND
WITH THE STUBBORN TROUGH OVER THE CENTRAL U.S...IT WILL PUSH A
SYSTEM TOWARDS SOUTHERN NEW ENGLAND BY SUNDAY. THIS SYSTEM MAY
SUPPORT A MODEST SWATH OF OVERRUNNING SNOW OVER SOUTHERN NEW
ENGLAND.

DETAILS...

MONDAY INTO TUESDAY...MODERATE CONFIDENCE.

A WEAK WAVE OF LOW PRESSURE DEVELOPS ALONG THE SOUTHEAST COAST
MONDAY...AND WILL BE ON A DEVELOPING WARM FRONTAL BOUNDARY. THIS LOW
REMAINS WEAK AS THE WARM FRONT MOVES SLOWLY NORTH MONDAY NIGHT INTO
TUESDAY. APPEARS THAT THERE IS DECENT WARM ADVECTION AHEAD OF THIS
WAVE. SEVERAL HI-RES GUIDANCE MODELS SHOW THAT THERE IS THE
POTENTIAL FOR COLD AIR DAMMING ACROSS THE INTERIOR INTO TUESDAY.
BIGGEST QUESTION WILL BE IS THERE ENOUGH MOISTURE FOR PRECIP DURING
THIS TIME FRAME. DUE TO A STRENGTHENING LLJ PROVIDING A GOOD SOURCE OF
LIFT ANTICIPATE PRECIP TO DEVELOP AND OVERSPREAD ACROSS SOUTHERN NEW
ENGLAND. IF THIS PLAYS OUT WITH COLD AIR DAMMING AND WARM AIR
ADVECTION...THEN WE COULD SEE FREEZING RAIN/DRIZZLE ACROSS THE I-91
CORRIDOR LATE MONDAY INTO TUESDAY MORNING. DURING THE DAY ON
TUESDAY...GOOD AMOUNT OF WARM AIR WILL PUSH SURFACE TEMPS ABOVE
FREEZING BY THE LATE MORNING ALLOWING FOR ANY PRECIP TO BE MORE OF
THE LIQUID VARIETY AHEAD OF THE CHRISTMAS EVE STORM. HOWEVER
GUIDANCE IS ALWAYS TOO FAST IN SCOURING TEMPS OUT ESP ACROSS THE CT
VALLEY SO WE WILL NEED TO MONITOR THIS CLOSELY...ESP DUE TO LIGHT
WINDS AND THE HIGH IN EASTERN CANADA. A WINTER WX ADVISORY MAY BE
NEEDED FOR THE LIGHT ICING POTENTIAL.

WE COULD ALSO SEE SOME MINOR COASTAL FLOODING CONCERNS ON TUESDAY. SEE
BELOW FOR MORE DETAILS.

WEDNESDAY INTO THURSDAY...HIGH CONFIDENCE IN SYSTEM LOW CONFIDENCE
ON DETAILS.

ANOMALOUS SYSTEM WILL STRENGTHEN OVER THE GREAT LAKES TUESDAY INTO
WEDNESDAY. A SECONDARY SHORTWAVE WILL ROUND THE DEEP TROUGH AND
DEVELOP A SECONDARY LOW PRESSURE ALONG THE COLD FRONT. THIS
SECONDARY LOW WILL STRENGTHEN AND PASS WEST OF SOUTHERN NEW ENGLAND.
THIS SYSTEM WILL CONTINUE TO DEEPEN AS IT MOVES TOWARDS EASTERN
CANADA SWINGING A COLD FRONT ACROSS THE NORTHEAST.

STRONG SOUTHERLY JET OUT AHEAD OF THE FRONT WITH A GULF MOISTURE
CONNECTION WILL IMPACT SOUTHERN NEW ENGLAND ON CHRISTMAS EVE. THIS
STRONG JET WILL YIELD FOR PCPN IN THE LIQUID VARIETY.  PW ANOMALIES
ARE BETWEEN +4 TO +5 STANDARD DEVIATIONS ABOVE NORMAL WHICH IS QUITE
ANOMALOUS FOR THIS TIME OF YEAR. IN FACT CURRENT PWATS ARE PROGGED
ABOVE 1.6 INCHES WITH MODEL QPF OVER 2 INCHES...AT THE VERY LEAST
COULD SEE URBAN AND POOR DRAINAGE FLOODING. LATEST EC EVEN SHOWS
OVER 2.5 INCHES OF QPF...AND WITH THE TROPICAL CONNECTION AND STRONG
SOUTHERLY FLOW COULD SEE HIGHER AMOUNTS DUE TO TOPOGRAPHY
ENHANCEMENTS. RAINFALL RECORDS MAY FALL IF EVERYTHING FALLS INTO
PLACE.

AHEAD OF THE FRONT...SOUTHERN NEW ENGLAND WILL WARM SECTOR WED INTO
THUR MORNING ALLOWING FOR TEMPERATURES TO BE WELL ABOVE AVERAGE. IN
FACT WE MAY BE CLOSE AT BREAKING RECORD HIGH TEMPS IF TEMPS WARM TO
60F OR ABOVE ON CHRISTMAS EVE. SINCE WE WILL BE IN THE WARM
SECTOR...AND SHOWALTERS CLOSE TO ZERO...ISOLATED THUNDER IS STILL
POSSIBLE.

STRONG LOW LEVEL WINDS WILL ALSO BE A CONCERN ESPECIALLY WEDNESDAY
NIGHT. THE ECMWF SHOWS EAST-SOUTHEAST WINDS 30-40 KNOTS ON WEDNESDAY
INCREASING TO 60-75 KNOTS BY WEDNESDAY NIGHT. STRONG DOWNPOURS MAY
OVERCOME THE LOW LEVEL INVERSION AND BRING STRONG GUSTS OF AT LEAST
30-40 KNOTS ESPECIALLY ALONG THE SOUTH COAST. A WIND ADVISORY MAY BE
NEEDED IN SOME AREAS.

CHRISTMAS DAY...MODERATE CONFIDENCE.

AS THE COLD FRONT PASSES THROUGH EARLY CHRISTMAS DAY...THE WEST
WINDS WILL HELP DRY THE AIRMASS ALLOWING FOR PARTLY SUNNY SKIES.
STRONG CAA ON THURSDAY WILL ALLOW DESCENT MIXING. WINDS IN THE SFC-
850 MB LAYER WILL BE 30-40 KNOTS AND POSSIBLY A LITTLE
HIGHER...WHICH WOULD REQUIRE A WIND ADVISORY FOR MUCH OF THE AREA.

FRIDAY-SUNDAY...LOWER CONFIDENCE

WEAK HIGH PRESSURE BUILDS OVER THE AREA FRIDAY INTO SATURDAY. THE
NEXT SHORTWAVE APPROACHES LATE SATURDAY INTO SUNDAY AND SHOULD BRING
INCREASING CLOUDS FROM WEST TO EAST ALONG WITH A CHANCE OF RAIN OR
SNOW SHOWERS MAINLY IN THE AFTERNOON AND AT NIGHT.

&&

.AVIATION /12Z 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.  MAINLY MVFR CONDITIONS
SOUTH OF THE MA TURNPIKE WITH BORDERLINE VFR TO MARGINAL MVFR CIGS
NORTH OF THE PIKE THROUGH TONIGHT.  AN AREA OF SNOW SHOWERS WILL
EXPAND MAINLY ACROSS AREAS SOUTH OF THE PIKE THIS MORNING...BUT A
FEW SNOW SHOWERS WILL STILL AFFECT NORTHERN MA.  VSBYS/CIGS MAY
BRIEFLY DROP TO IFR LEVELS IN NORTHERN CT/RI/SE MA.  PTYPE WILL BE
RAIN SHOWERS ACROSS MOST OF PLYMOUTH COUNTY AND ONTO THE
CAPE/ISLANDS WITH SNOW SHOWERS NORTH AND WEST.  BULK OF PRECIP THIS
MORNING...BUT A FEW LINGERING RAIN/SNOW SHOWERS STILL POSSIBLE THIS
AFTERNOON AND EVENING.

KBOS TERMINAL...MODERATE CONFIDENCE.  A FEW SNOW SHOWERS POSSIBLE
THIS MORNING BUT BULK OF ACTIVITY SHOULD BE SOUTH OF THE TERMINAL.

KBDL TERMINAL...MODERATE CONFIDENCE.  PERIOD OF SNOW SHOWERS THIS
MORNING MAY DROP AN INCH OR TWO OF SNOW.  MVFR CONDITIONS DOMINATE
TODAY....BUT A BRIEF PERIOD OF IFR CONDITIONS ARE POSSIBLE THIS
MORNING IN SNOW SHOWERS.

OUTLOOK...MONDAY THROUGH THURSDAY...MODERATE CONFIDENCE.

MONDAY...MVFR CIGS CONTINUE IN RI/EASTERN MASS IN MARINE EAST FLOW.
VFR IN THE WEST.

TUESDAY...VFR WITH SCATTERED MVFR IN ANY RAIN/SNOW SHOWERS.

WEDNESDAY...CONDITIONS LOWERING TO IFR IN RAIN/HEAVY RAIN. ISOLATED
THUNDERSTORMS POSSIBLE ESPECIALLY WEDNESDAY NIGHT. EAST-SOUTHEAST
SURFACE WINDS MAY GUST TO 35-45 KNOTS. WINDS AT 2000 FEET AGL WILL
REACH 50-60 KNOTS WEDNESDAY AFTERNOON AND EARLY NIGHT CREATING LOW
LEVEL WIND SHEAR CONCERNS.

CHRISTMAS DAY...WEST WIND GUSTING 30-40 KNOTS. CONDITIONS IMPROVING
TO VFR AS THE WIND BRINGS IN COOLER DRIER AIR.

&&

.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.

HIGH PRESSURE ACROSS QUEBEC WILL RESULT IN NORTHEAST WINDS ACROSS
THE WATERS THAT WILL GUST TO BETWEEN 15 AND 20 KNOTS.  THIS WILL
RESULT IN 2 TO 4 FOOT SEAS.  HOWEVER...NO HEADLINES PLANNED AS
CONDITIONS SHOULD REMAIN BELOW SMALL CRAFT ADVISORY THRESHOLDS.

OUTLOOK...MONDAY THROUGH THURSDAY...MODERATE CONFIDENCE

MONDAY...EAST TO NORTHEAST WINDS GUSTING AROUND 15 KNOTS OR LESS.
SEAS WILL HOLD AROUND 3-4 FEET...MAY INCREASE TO 5FT IN NORTHEAST
FLOW AS GUIDANCE MAY BE UNDERDONE.

TUESDAY... INCREASING EAST WINDS WITH FREQUENT GUSTS 25 TO 30 KNOTS.
SEAS WILL BUILD TO 5-6 FEET ON THE EXPOSED WATERS.  A SMALL CRAFT
ADVISORY MAY BE NEEDED.

WEDNESDAY...RAIN WILL BE HEAVY AT TIMES PRODUCING POOR VISIBILITY.
INCREASING SOUTHEAST WINDS 20-25 SUSTAINED AND 40 KNOT GUSTS.  WINDS
SHOULD SHIFT TO SOUTH WEDNESDAY NIGHT AND SOUTHWEST TOWARD THURSDAY
MORNING. RAIN WILL TAPER OFF WITH THE WIND SHIFT TO SOUTHWEST. SEAS
WILL CONTINUE TO BUILD WITH 7-11 FEET HEIGHTS ON THE EXPOSED WATERS.
A GALE WARNING WILL BE NEEDED...WITH A LOW PROB OF A FEW STORM FORCE
GUSTS ACROSS THE EASTERN OUTER WATERS.

CHRISTMAS DAY... WEST SOUTHWEST WINDS WILL CONTINUE TO GUST 35-40
KNOTS...SO A CONTINUED GALE WARNING MAY BE NEEDED. SEAS OF 7-15 FEET
ARE POSSIBLE ON THE EXPOSED WATERS...AND 5 FEET IS POSSIBLE ON SOME
OF THE NEARSHORE WATERS.

&&

.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES WILL OCCUR TUESDAY THROUGH THURSDAY. BREAKING
IT DOWN...ON TUESDAY HIGH TIDE AT BOSTON WILL BE 11.6 FT. THERE WILL
BE ONSHORE FLOW DURING THIS HIGH TIDE ALLOWING FOR MINOR SPLASHOVER.
IF WIND GUSTS INCREASE THEN COULD POSSIBLE SEE MINOR COASTAL
FLOODING.

ON WEDNESDAY...WINDS WILL SWITCH TO A MORE SOUTHEASTERLY FLOW DURING
THE DAY AND INCREASE QUICKLY FROM APPROACHING SYSTEM AND DECENT
PRESSURE FALLS. WEDNESDAY AFTERNOON HIGH TIDE IN BOSTON IS 11.7 FT
AND WITH ANY STRENGTH ON THE EASTERLY WIND FLOW WILL PUSH THE TIDE
OVER. RIGHT NOW BELIEVE MINOR COASTAL FLOODING IS POSSIBLE ALONG THE
EAST COASTLINE.

WEDNESDAY EVENING...THE WIND GOES IN A MORE SOUTHERLY DIRECTION AND
THE TIDE WILL BE INCREASE ACROSS THE SOUTH COAST. HIGH TIDE IN
PROVIDENCE WILL BE 5.2 FT. 925 MB LLJ STRENGTHENS TO 50-60 KTS WHICH
COULD PUSH A DECENT SURGE UP ALONG THE SOUTH COAST DURING THE TIME
OF HIGH TIDE. THINKING THAT MINOR COASTAL FLOODING COULD OCCUR BUT
CANNOT RULE OUT MODERATE ALONG THE SOUTH COAST...ESP IF LLJ
STRENGTHENS EVEN MORE.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...FRANK/DUNTEN
NEAR TERM...FRANK/DUNTEN
SHORT TERM...FRANK
LONG TERM...DUNTEN
AVIATION...FRANK/DUNTEN
MARINE...FRANK/DUNTEN
TIDES/COASTAL FLOODING...STAFF





000
FXUS61 KBOX 211154
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
654 AM EST SUN DEC 21 2014

.SYNOPSIS...
AN AREA OF SNOW SHOWERS WILL AFFECT AREAS MAINLY SOUTH OF THE MA
TURNPIKE THIS MORNING...EXCEPT IT WILL BE MILD ENOUGH FOR RAIN
SHOWERS ACROSS THE FAR SOUTHEAST NEW ENGLAND COAST. WEAK LOW
PRESSURE WILL PASS SOUTH OF NEW ENGLAND BRINGING ANOTHER PERIOD OF
PRECIPITATION MONDAY NIGHT AND TUESDAY. A MUCH STRONGER STORM
PASSING WEST OF NEW ENGLAND WILL BRING HEAVY RAINFALL...GUSTY
WINDS AND COASTAL FLOODING CONCERNS TO THE REGION WEDNESDAY AND
WEDNESDAY NIGHT. DRY BUT VERY WINDY CONDITIONS FOLLOW FOR
CHRISTMAS DAY.

&&

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

700 PM UPDATE...

VERY LITTLE CHANGES TO THE FORECAST AS OVERALL TREND IS ON TRACK
FOR THIS MORNING. RADAR ECHOES LOOK A LITTLE DECEIVING AS SNOW HAS
SPREAD ACROSS A GOOD PORTION OF SOUTHERN NEW ENGLAND PER OBS.
ANTICIPATE MORE WIDE SPREAD BUT LIGHT SNOW OVER THE NEXT HOUR OR
TWO OUTSIDE OF THE COASTAL FRONT...WHICH IS DRAPED OVER GHG-TAN-
UUU.

PREVIOUS DISCUSSION...

APPROACHING SHORTWAVE HAS ALLOWED AN AREA LIGHT SNOW SHOWERS TO
EXPAND SOUTH OF THE MA TURNPIKE VERY EARLY THIS MORNING...BUT A FEW
SNOW SHOWERS DID EXTEND INTO NORTHERN MA.  RADAR IMAGERY ACTUALLY
OVER SHOOTING SOME OF THE ACTIVITY ACROSS NORTHERN CT...BASED ON
OBSERVATIONS.  THE RAIN/SNOW LINE RUNS ROUGHLY FROM NEWPORT...TO
TAUNTON AND JUST NORTH OF MARSHFIELD.  OVERALL...DO NOT EXPECT MUCH
CHANGE IN THE RAIN/SNOW LINE THIS MORNING BASED ON THERMAL PROFILES
AND POSITIONING OF THE COASTAL FRONT.

MAIN UNCERTAINTY IS JUST HOW MUCH SNOW OCCURS THIS MORNING WITH THE
SHORTWAVE MOVING ACROSS CT.  GIVEN THE TRACK OF THE SHORTWAVE...BEST
FORCING WILL BE LOCATED SOUTH OF THE MA TURNPIKE AND ESPECIALLY
ACROSS NORTHERN CT/RI.  WE WILL FORECAST 1 TO 2 INCHES OF SNOW
ACROSS THIS REGION...BUT A FEW ISOLATED 3 INCH AMOUNTS CAN NOT BE
RULED OUT. MEANWHILE...AREAS NORTH OF THE MA TURNPIKE WILL BE
REMOVED FROM THE BEST FORCING...BUT STILL SEE SOME SCATTERED
SHOWERS.  ACCUMS IN THIS AREA LIKELY TO BE A DUSTING TO LESS THAN AN
INCH.

ALSO...SOME OF THE PRECIPITATION CURRENTLY ACROSS SOUTHEAST MA IS
BEING ENHANCED FROM THE COASTAL FRONT.  A LOT OF THIS PRECIP WILL
BE IN THE FORM OF RAIN SHOWERS ACROSS PLYMOUTH AND EVEN INTO
PORTIONS OF BRISTOL COUNTY...POINTS SOUTH AND EAST.  HOWEVER...AT
LEAST THE SLIGHTLY HIGHER TERRAIN OF SOUTHEAST MA SHOULD SEE SNOW
SHOWERS.  WILL HAVE TO KEEP A CLOSE EYE ON IF COASTAL FRONT SHIFTS
SLIGHTLY THIS MORNING.  IT COULD MEAN THE DIFFERENCE BETWEEN AN AREA
GETTING MAINLY RAIN SHOWERS OR PERHAPS AN INCH OR SO OF SNOW.
OVERALL...DO NOT EXPECT THE COASTAL FRONT TO MOVE TOO MUCH THIS
MORNING...BUT JUST A FEW MILES CAN MAKE DIFFERENCE FOR A
PARTICULARLY NEIGHBORHOOD.

BULK OF PRECIPITATION WILL BE THIS MORNING WITH THE SHORTWAVE.
HOWEVER...ENOUGH LOW LEVEL MOISTURE/WEAK LIFT WILL REMAIN THIS
AFTERNOON FOR AT LEAST THIS RISK OF SCATTERED PRECIPITATION AND WILL
MAINTAIN SOME POPS.  HIGH TEMPS MAINLY IN THE 30S.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
TONIGHT...

A RATHER CLOUDY AND RAW NIGHT ACROSS SOUTHERN NEW ENGLAND.  WHILE
THERE IS NOT A SIGNIFICANT SHORTWAVE TO TRIGGER A LOT OF
PRECIPITATION...PLENTY OF LOW LEVEL MOISTURE/WEAK SHALLOW LIFT
REMAINS.  THIS MAY BE ENOUGH TO RESULT IN A FEW RAIN/SNOW SHOWER
FROM TIME TO TIME.  PTYPE...WOULD BE MAINLY SNOW SHOWERS EXCEPT TO
THE SOUTHEAST OF A NEWPORT...TO TAUNTON...TO JUST NORTH OF
MARSHFIELD LINE.  AGAIN...MUCH OF THE NIGHT WILL PROBABLY END UP
DRY...BUT JUST THE RISK FOR A FEW RAIN/SNOW SHOWERS.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
HIGHLIGHTS...

* WEAK SHORTWAVE ON MON NIGHT/TUESDAY COULD BRING WINTRY
  MIX/FREEZING RAIN TO THE INTERIOR
* ANOMALOUS SYSTEM ACROSS THE GREAT LAKES WILL BRING HEAVY
  RAIN...GUSTY WINDS AND COASTAL FLOODING CONCERNS AROUND CHRISTMAS
  EVE
* BLUSTERY BUT AIRMASS WILL BE DRYING OUT ON CHRISTMAS DAY

OVERVIEW...

THE MODELS AND ENSEMBLES OFFER A REASONABLY SIMILAR AND PREDICTABLE
LARGER SCALE MID TO UPPER LEVEL PATTERN EVOLUTION FOR MUCH OF THE
UPCOMING WEEK. THIS ACTIVE FLOW REGIME DEVELOPS SEVERAL MID-UPPER
LEVEL TROUGH AND ASSOCIATED/UNSETTLING LEAD SURFACE LOW/FRONTAL
SYSTEMS AND PCPN SWATHS PROGRESS STEADILY ACROSS THE LOWER 48. THE
FIRST AMPLIFIED/DEEP LEAD SYSTEM WORKS ACROSS THE ERN/NERN US INTO
ERN CANADA CHRISTMAS EVE INTO CHRISTMAS ALLOWING FOR A MOIST/WARMED
AIRMASS IN ADVANCE OF FRONTAL APPROACH WITH HEAVIEST LEAD QPF
POTENTIAL OVER NEW ENGLAND. BIGGEST QUESTION IS THE EVOLUTION OF THE
SECONDARY LOW PRESSURE SYSTEM. 00Z GUIDANCE HAS BACKED OFF ON THE
STRENGTH OF THE LOW AND IS HAVING ISSUES ON HOW TO HANDLE ITS
EVOLUTION. THE EC AND GFS HAVE SLOWED DOWN THE SYSTEM SLIGHTLY WITH
THE EC HAVING MORE OF A NEGATIVE TROUGH VS THE GFS. BELIEVE THE
UKMET IS A GOOD COMPROMISE AT IS WAS THE FIRST DETERMINISTIC
GUIDANCE ON TAMPERING DOWN THE FIRST MAIN LOW...WHILE THE CMC IS OUT
TO LUNCH. REGARDLESS THIS IS A VERY ANOMALOUS SYSTEM THAT IS ABOUT 4
STANDARD DEVIATIONS AWAY.

A SECONDARY SYSTEM DEEPENS ACROSS THE FOUR CORNERS ON FRIDAY AND
WITH THE STUBBORN TROUGH OVER THE CENTRAL U.S...IT WILL PUSH A
SYSTEM TOWARDS SOUTHERN NEW ENGLAND BY SUNDAY. THIS SYSTEM MAY
SUPPORT A MODEST SWATH OF OVERRUNNING SNOW OVER SOUTHERN NEW
ENGLAND.

DETAILS...

MONDAY INTO TUESDAY...MODERATE CONFIDENCE.

A WEAK WAVE OF LOW PRESSURE DEVELOPS ALONG THE SOUTHEAST COAST
MONDAY...AND WILL BE ON A DEVELOPING WARM FRONTAL BOUNDARY. THIS LOW
REMAINS WEAK AS THE WARM FRONT MOVES SLOWLY NORTH MONDAY NIGHT INTO
TUESDAY. APPEARS THAT THERE IS DECENT WARM ADVECTION AHEAD OF THIS
WAVE. SEVERAL HI-RES GUIDANCE MODELS SHOW THAT THERE IS THE
POTENTIAL FOR COLD AIR DAMMING ACROSS THE INTERIOR INTO TUESDAY.
BIGGEST QUESTION WILL BE IS THERE ENOUGH MOISTURE FOR PRECIP DURING
THIS TIME FRAME. DUE TO A STRENGTHENING LLJ PROVIDING A GOOD SOURCE OF
LIFT ANTICIPATE PRECIP TO DEVELOP AND OVERSPREAD ACROSS SOUTHERN NEW
ENGLAND. IF THIS PLAYS OUT WITH COLD AIR DAMMING AND WARM AIR
ADVECTION...THEN WE COULD SEE FREEZING RAIN/DRIZZLE ACROSS THE I-91
CORRIDOR LATE MONDAY INTO TUESDAY MORNING. DURING THE DAY ON
TUESDAY...GOOD AMOUNT OF WARM AIR WILL PUSH SURFACE TEMPS ABOVE
FREEZING BY THE LATE MORNING ALLOWING FOR ANY PRECIP TO BE MORE OF
THE LIQUID VARIETY AHEAD OF THE CHRISTMAS EVE STORM. HOWEVER
GUIDANCE IS ALWAYS TOO FAST IN SCOURING TEMPS OUT ESP ACROSS THE CT
VALLEY SO WE WILL NEED TO MONITOR THIS CLOSELY...ESP DUE TO LIGHT
WINDS AND THE HIGH IN EASTERN CANADA. A WINTER WX ADVISORY MAY BE
NEEDED FOR THE LIGHT ICING POTENTIAL.

WE COULD ALSO SEE SOME MINOR COASTAL FLOODING CONCERNS ON TUESDAY. SEE
BELOW FOR MORE DETAILS.

WEDNESDAY INTO THURSDAY...HIGH CONFIDENCE IN SYSTEM LOW CONFIDENCE
ON DETAILS.

ANOMALOUS SYSTEM WILL STRENGTHEN OVER THE GREAT LAKES TUESDAY INTO
WEDNESDAY. A SECONDARY SHORTWAVE WILL ROUND THE DEEP TROUGH AND
DEVELOP A SECONDARY LOW PRESSURE ALONG THE COLD FRONT. THIS
SECONDARY LOW WILL STRENGTHEN AND PASS WEST OF SOUTHERN NEW ENGLAND.
THIS SYSTEM WILL CONTINUE TO DEEPEN AS IT MOVES TOWARDS EASTERN
CANADA SWINGING A COLD FRONT ACROSS THE NORTHEAST.

STRONG SOUTHERLY JET OUT AHEAD OF THE FRONT WITH A GULF MOISTURE
CONNECTION WILL IMPACT SOUTHERN NEW ENGLAND ON CHRISTMAS EVE. THIS
STRONG JET WILL YIELD FOR PCPN IN THE LIQUID VARIETY.  PW ANOMALIES
ARE BETWEEN +4 TO +5 STANDARD DEVIATIONS ABOVE NORMAL WHICH IS QUITE
ANOMALOUS FOR THIS TIME OF YEAR. IN FACT CURRENT PWATS ARE PROGGED
ABOVE 1.6 INCHES WITH MODEL QPF OVER 2 INCHES...AT THE VERY LEAST
COULD SEE URBAN AND POOR DRAINAGE FLOODING. LATEST EC EVEN SHOWS
OVER 2.5 INCHES OF QPF...AND WITH THE TROPICAL CONNECTION AND STRONG
SOUTHERLY FLOW COULD SEE HIGHER AMOUNTS DUE TO TOPOGRAPHY
ENHANCEMENTS. RAINFALL RECORDS MAY FALL IF EVERYTHING FALLS INTO
PLACE.

AHEAD OF THE FRONT...SOUTHERN NEW ENGLAND WILL WARM SECTOR WED INTO
THUR MORNING ALLOWING FOR TEMPERATURES TO BE WELL ABOVE AVERAGE. IN
FACT WE MAY BE CLOSE AT BREAKING RECORD HIGH TEMPS IF TEMPS WARM TO
60F OR ABOVE ON CHRISTMAS EVE. SINCE WE WILL BE IN THE WARM
SECTOR...AND SHOWALTERS CLOSE TO ZERO...ISOLATED THUNDER IS STILL
POSSIBLE.

STRONG LOW LEVEL WINDS WILL ALSO BE A CONCERN ESPECIALLY WEDNESDAY
NIGHT. THE ECMWF SHOWS EAST-SOUTHEAST WINDS 30-40 KNOTS ON WEDNESDAY
INCREASING TO 60-75 KNOTS BY WEDNESDAY NIGHT. STRONG DOWNPOURS MAY
OVERCOME THE LOW LEVEL INVERSION AND BRING STRONG GUSTS OF AT LEAST
30-40 KNOTS ESPECIALLY ALONG THE SOUTH COAST. A WIND ADVISORY MAY BE
NEEDED IN SOME AREAS.

CHRISTMAS DAY...MODERATE CONFIDENCE.

AS THE COLD FRONT PASSES THROUGH EARLY CHRISTMAS DAY...THE WEST
WINDS WILL HELP DRY THE AIRMASS ALLOWING FOR PARTLY SUNNY SKIES.
STRONG CAA ON THURSDAY WILL ALLOW DESCENT MIXING. WINDS IN THE SFC-
850 MB LAYER WILL BE 30-40 KNOTS AND POSSIBLY A LITTLE
HIGHER...WHICH WOULD REQUIRE A WIND ADVISORY FOR MUCH OF THE AREA.

FRIDAY-SUNDAY...LOWER CONFIDENCE

WEAK HIGH PRESSURE BUILDS OVER THE AREA FRIDAY INTO SATURDAY. THE
NEXT SHORTWAVE APPROACHES LATE SATURDAY INTO SUNDAY AND SHOULD BRING
INCREASING CLOUDS FROM WEST TO EAST ALONG WITH A CHANCE OF RAIN OR
SNOW SHOWERS MAINLY IN THE AFTERNOON AND AT NIGHT.

&&

.AVIATION /12Z 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.  MAINLY MVFR CONDITIONS
SOUTH OF THE MA TURNPIKE WITH BORDERLINE VFR TO MARGINAL MVFR CIGS
NORTH OF THE PIKE THROUGH TONIGHT.  AN AREA OF SNOW SHOWERS WILL
EXPAND MAINLY ACROSS AREAS SOUTH OF THE PIKE THIS MORNING...BUT A
FEW SNOW SHOWERS WILL STILL AFFECT NORTHERN MA.  VSBYS/CIGS MAY
BRIEFLY DROP TO IFR LEVELS IN NORTHERN CT/RI/SE MA.  PTYPE WILL BE
RAIN SHOWERS ACROSS MOST OF PLYMOUTH COUNTY AND ONTO THE
CAPE/ISLANDS WITH SNOW SHOWERS NORTH AND WEST.  BULK OF PRECIP THIS
MORNING...BUT A FEW LINGERING RAIN/SNOW SHOWERS STILL POSSIBLE THIS
AFTERNOON AND EVENING.

KBOS TERMINAL...MODERATE CONFIDENCE.  A FEW SNOW SHOWERS POSSIBLE
THIS MORNING BUT BULK OF ACTIVITY SHOULD BE SOUTH OF THE TERMINAL.

KBDL TERMINAL...MODERATE CONFIDENCE.  PERIOD OF SNOW SHOWERS THIS
MORNING MAY DROP AN INCH OR TWO OF SNOW.  MVFR CONDITIONS DOMINATE
TODAY....BUT A BRIEF PERIOD OF IFR CONDITIONS ARE POSSIBLE THIS
MORNING IN SNOW SHOWERS.

OUTLOOK...MONDAY THROUGH THURSDAY...MODERATE CONFIDENCE.

MONDAY...MVFR CIGS CONTINUE IN RI/EASTERN MASS IN MARINE EAST FLOW.
VFR IN THE WEST.

TUESDAY...VFR WITH SCATTERED MVFR IN ANY RAIN/SNOW SHOWERS.

WEDNESDAY...CONDITIONS LOWERING TO IFR IN RAIN/HEAVY RAIN. ISOLATED
THUNDERSTORMS POSSIBLE ESPECIALLY WEDNESDAY NIGHT. EAST-SOUTHEAST
SURFACE WINDS MAY GUST TO 35-45 KNOTS. WINDS AT 2000 FEET AGL WILL
REACH 50-60 KNOTS WEDNESDAY AFTERNOON AND EARLY NIGHT CREATING LOW
LEVEL WIND SHEAR CONCERNS.

CHRISTMAS DAY...WEST WIND GUSTING 30-40 KNOTS. CONDITIONS IMPROVING
TO VFR AS THE WIND BRINGS IN COOLER DRIER AIR.

&&

.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.

HIGH PRESSURE ACROSS QUEBEC WILL RESULT IN NORTHEAST WINDS ACROSS
THE WATERS THAT WILL GUST TO BETWEEN 15 AND 20 KNOTS.  THIS WILL
RESULT IN 2 TO 4 FOOT SEAS.  HOWEVER...NO HEADLINES PLANNED AS
CONDITIONS SHOULD REMAIN BELOW SMALL CRAFT ADVISORY THRESHOLDS.

OUTLOOK...MONDAY THROUGH THURSDAY...MODERATE CONFIDENCE

MONDAY...EAST TO NORTHEAST WINDS GUSTING AROUND 15 KNOTS OR LESS.
SEAS WILL HOLD AROUND 3-4 FEET...MAY INCREASE TO 5FT IN NORTHEAST
FLOW AS GUIDANCE MAY BE UNDERDONE.

TUESDAY... INCREASING EAST WINDS WITH FREQUENT GUSTS 25 TO 30 KNOTS.
SEAS WILL BUILD TO 5-6 FEET ON THE EXPOSED WATERS.  A SMALL CRAFT
ADVISORY MAY BE NEEDED.

WEDNESDAY...RAIN WILL BE HEAVY AT TIMES PRODUCING POOR VISIBILITY.
INCREASING SOUTHEAST WINDS 20-25 SUSTAINED AND 40 KNOT GUSTS.  WINDS
SHOULD SHIFT TO SOUTH WEDNESDAY NIGHT AND SOUTHWEST TOWARD THURSDAY
MORNING. RAIN WILL TAPER OFF WITH THE WIND SHIFT TO SOUTHWEST. SEAS
WILL CONTINUE TO BUILD WITH 7-11 FEET HEIGHTS ON THE EXPOSED WATERS.
A GALE WARNING WILL BE NEEDED...WITH A LOW PROB OF A FEW STORM FORCE
GUSTS ACROSS THE EASTERN OUTER WATERS.

CHRISTMAS DAY... WEST SOUTHWEST WINDS WILL CONTINUE TO GUST 35-40
KNOTS...SO A CONTINUED GALE WARNING MAY BE NEEDED. SEAS OF 7-15 FEET
ARE POSSIBLE ON THE EXPOSED WATERS...AND 5 FEET IS POSSIBLE ON SOME
OF THE NEARSHORE WATERS.

&&

.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES WILL OCCUR TUESDAY THROUGH THURSDAY. BREAKING
IT DOWN...ON TUESDAY HIGH TIDE AT BOSTON WILL BE 11.6 FT. THERE WILL
BE ONSHORE FLOW DURING THIS HIGH TIDE ALLOWING FOR MINOR SPLASHOVER.
IF WIND GUSTS INCREASE THEN COULD POSSIBLE SEE MINOR COASTAL
FLOODING.

ON WEDNESDAY...WINDS WILL SWITCH TO A MORE SOUTHEASTERLY FLOW DURING
THE DAY AND INCREASE QUICKLY FROM APPROACHING SYSTEM AND DECENT
PRESSURE FALLS. WEDNESDAY AFTERNOON HIGH TIDE IN BOSTON IS 11.7 FT
AND WITH ANY STRENGTH ON THE EASTERLY WIND FLOW WILL PUSH THE TIDE
OVER. RIGHT NOW BELIEVE MINOR COASTAL FLOODING IS POSSIBLE ALONG THE
EAST COASTLINE.

WEDNESDAY EVENING...THE WIND GOES IN A MORE SOUTHERLY DIRECTION AND
THE TIDE WILL BE INCREASE ACROSS THE SOUTH COAST. HIGH TIDE IN
PROVIDENCE WILL BE 5.2 FT. 925 MB LLJ STRENGTHENS TO 50-60 KTS WHICH
COULD PUSH A DECENT SURGE UP ALONG THE SOUTH COAST DURING THE TIME
OF HIGH TIDE. THINKING THAT MINOR COASTAL FLOODING COULD OCCUR BUT
CANNOT RULE OUT MODERATE ALONG THE SOUTH COAST...ESP IF LLJ
STRENGTHENS EVEN MORE.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...FRANK/DUNTEN
NEAR TERM...FRANK/DUNTEN
SHORT TERM...FRANK
LONG TERM...DUNTEN
AVIATION...FRANK/DUNTEN
MARINE...FRANK/DUNTEN
TIDES/COASTAL FLOODING...STAFF





000
FXUS61 KBOX 211154
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
654 AM EST SUN DEC 21 2014

.SYNOPSIS...
AN AREA OF SNOW SHOWERS WILL AFFECT AREAS MAINLY SOUTH OF THE MA
TURNPIKE THIS MORNING...EXCEPT IT WILL BE MILD ENOUGH FOR RAIN
SHOWERS ACROSS THE FAR SOUTHEAST NEW ENGLAND COAST. WEAK LOW
PRESSURE WILL PASS SOUTH OF NEW ENGLAND BRINGING ANOTHER PERIOD OF
PRECIPITATION MONDAY NIGHT AND TUESDAY. A MUCH STRONGER STORM
PASSING WEST OF NEW ENGLAND WILL BRING HEAVY RAINFALL...GUSTY
WINDS AND COASTAL FLOODING CONCERNS TO THE REGION WEDNESDAY AND
WEDNESDAY NIGHT. DRY BUT VERY WINDY CONDITIONS FOLLOW FOR
CHRISTMAS DAY.

&&

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

700 PM UPDATE...

VERY LITTLE CHANGES TO THE FORECAST AS OVERALL TREND IS ON TRACK
FOR THIS MORNING. RADAR ECHOES LOOK A LITTLE DECEIVING AS SNOW HAS
SPREAD ACROSS A GOOD PORTION OF SOUTHERN NEW ENGLAND PER OBS.
ANTICIPATE MORE WIDE SPREAD BUT LIGHT SNOW OVER THE NEXT HOUR OR
TWO OUTSIDE OF THE COASTAL FRONT...WHICH IS DRAPED OVER GHG-TAN-
UUU.

PREVIOUS DISCUSSION...

APPROACHING SHORTWAVE HAS ALLOWED AN AREA LIGHT SNOW SHOWERS TO
EXPAND SOUTH OF THE MA TURNPIKE VERY EARLY THIS MORNING...BUT A FEW
SNOW SHOWERS DID EXTEND INTO NORTHERN MA.  RADAR IMAGERY ACTUALLY
OVER SHOOTING SOME OF THE ACTIVITY ACROSS NORTHERN CT...BASED ON
OBSERVATIONS.  THE RAIN/SNOW LINE RUNS ROUGHLY FROM NEWPORT...TO
TAUNTON AND JUST NORTH OF MARSHFIELD.  OVERALL...DO NOT EXPECT MUCH
CHANGE IN THE RAIN/SNOW LINE THIS MORNING BASED ON THERMAL PROFILES
AND POSITIONING OF THE COASTAL FRONT.

MAIN UNCERTAINTY IS JUST HOW MUCH SNOW OCCURS THIS MORNING WITH THE
SHORTWAVE MOVING ACROSS CT.  GIVEN THE TRACK OF THE SHORTWAVE...BEST
FORCING WILL BE LOCATED SOUTH OF THE MA TURNPIKE AND ESPECIALLY
ACROSS NORTHERN CT/RI.  WE WILL FORECAST 1 TO 2 INCHES OF SNOW
ACROSS THIS REGION...BUT A FEW ISOLATED 3 INCH AMOUNTS CAN NOT BE
RULED OUT. MEANWHILE...AREAS NORTH OF THE MA TURNPIKE WILL BE
REMOVED FROM THE BEST FORCING...BUT STILL SEE SOME SCATTERED
SHOWERS.  ACCUMS IN THIS AREA LIKELY TO BE A DUSTING TO LESS THAN AN
INCH.

ALSO...SOME OF THE PRECIPITATION CURRENTLY ACROSS SOUTHEAST MA IS
BEING ENHANCED FROM THE COASTAL FRONT.  A LOT OF THIS PRECIP WILL
BE IN THE FORM OF RAIN SHOWERS ACROSS PLYMOUTH AND EVEN INTO
PORTIONS OF BRISTOL COUNTY...POINTS SOUTH AND EAST.  HOWEVER...AT
LEAST THE SLIGHTLY HIGHER TERRAIN OF SOUTHEAST MA SHOULD SEE SNOW
SHOWERS.  WILL HAVE TO KEEP A CLOSE EYE ON IF COASTAL FRONT SHIFTS
SLIGHTLY THIS MORNING.  IT COULD MEAN THE DIFFERENCE BETWEEN AN AREA
GETTING MAINLY RAIN SHOWERS OR PERHAPS AN INCH OR SO OF SNOW.
OVERALL...DO NOT EXPECT THE COASTAL FRONT TO MOVE TOO MUCH THIS
MORNING...BUT JUST A FEW MILES CAN MAKE DIFFERENCE FOR A
PARTICULARLY NEIGHBORHOOD.

BULK OF PRECIPITATION WILL BE THIS MORNING WITH THE SHORTWAVE.
HOWEVER...ENOUGH LOW LEVEL MOISTURE/WEAK LIFT WILL REMAIN THIS
AFTERNOON FOR AT LEAST THIS RISK OF SCATTERED PRECIPITATION AND WILL
MAINTAIN SOME POPS.  HIGH TEMPS MAINLY IN THE 30S.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
TONIGHT...

A RATHER CLOUDY AND RAW NIGHT ACROSS SOUTHERN NEW ENGLAND.  WHILE
THERE IS NOT A SIGNIFICANT SHORTWAVE TO TRIGGER A LOT OF
PRECIPITATION...PLENTY OF LOW LEVEL MOISTURE/WEAK SHALLOW LIFT
REMAINS.  THIS MAY BE ENOUGH TO RESULT IN A FEW RAIN/SNOW SHOWER
FROM TIME TO TIME.  PTYPE...WOULD BE MAINLY SNOW SHOWERS EXCEPT TO
THE SOUTHEAST OF A NEWPORT...TO TAUNTON...TO JUST NORTH OF
MARSHFIELD LINE.  AGAIN...MUCH OF THE NIGHT WILL PROBABLY END UP
DRY...BUT JUST THE RISK FOR A FEW RAIN/SNOW SHOWERS.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
HIGHLIGHTS...

* WEAK SHORTWAVE ON MON NIGHT/TUESDAY COULD BRING WINTRY
  MIX/FREEZING RAIN TO THE INTERIOR
* ANOMALOUS SYSTEM ACROSS THE GREAT LAKES WILL BRING HEAVY
  RAIN...GUSTY WINDS AND COASTAL FLOODING CONCERNS AROUND CHRISTMAS
  EVE
* BLUSTERY BUT AIRMASS WILL BE DRYING OUT ON CHRISTMAS DAY

OVERVIEW...

THE MODELS AND ENSEMBLES OFFER A REASONABLY SIMILAR AND PREDICTABLE
LARGER SCALE MID TO UPPER LEVEL PATTERN EVOLUTION FOR MUCH OF THE
UPCOMING WEEK. THIS ACTIVE FLOW REGIME DEVELOPS SEVERAL MID-UPPER
LEVEL TROUGH AND ASSOCIATED/UNSETTLING LEAD SURFACE LOW/FRONTAL
SYSTEMS AND PCPN SWATHS PROGRESS STEADILY ACROSS THE LOWER 48. THE
FIRST AMPLIFIED/DEEP LEAD SYSTEM WORKS ACROSS THE ERN/NERN US INTO
ERN CANADA CHRISTMAS EVE INTO CHRISTMAS ALLOWING FOR A MOIST/WARMED
AIRMASS IN ADVANCE OF FRONTAL APPROACH WITH HEAVIEST LEAD QPF
POTENTIAL OVER NEW ENGLAND. BIGGEST QUESTION IS THE EVOLUTION OF THE
SECONDARY LOW PRESSURE SYSTEM. 00Z GUIDANCE HAS BACKED OFF ON THE
STRENGTH OF THE LOW AND IS HAVING ISSUES ON HOW TO HANDLE ITS
EVOLUTION. THE EC AND GFS HAVE SLOWED DOWN THE SYSTEM SLIGHTLY WITH
THE EC HAVING MORE OF A NEGATIVE TROUGH VS THE GFS. BELIEVE THE
UKMET IS A GOOD COMPROMISE AT IS WAS THE FIRST DETERMINISTIC
GUIDANCE ON TAMPERING DOWN THE FIRST MAIN LOW...WHILE THE CMC IS OUT
TO LUNCH. REGARDLESS THIS IS A VERY ANOMALOUS SYSTEM THAT IS ABOUT 4
STANDARD DEVIATIONS AWAY.

A SECONDARY SYSTEM DEEPENS ACROSS THE FOUR CORNERS ON FRIDAY AND
WITH THE STUBBORN TROUGH OVER THE CENTRAL U.S...IT WILL PUSH A
SYSTEM TOWARDS SOUTHERN NEW ENGLAND BY SUNDAY. THIS SYSTEM MAY
SUPPORT A MODEST SWATH OF OVERRUNNING SNOW OVER SOUTHERN NEW
ENGLAND.

DETAILS...

MONDAY INTO TUESDAY...MODERATE CONFIDENCE.

A WEAK WAVE OF LOW PRESSURE DEVELOPS ALONG THE SOUTHEAST COAST
MONDAY...AND WILL BE ON A DEVELOPING WARM FRONTAL BOUNDARY. THIS LOW
REMAINS WEAK AS THE WARM FRONT MOVES SLOWLY NORTH MONDAY NIGHT INTO
TUESDAY. APPEARS THAT THERE IS DECENT WARM ADVECTION AHEAD OF THIS
WAVE. SEVERAL HI-RES GUIDANCE MODELS SHOW THAT THERE IS THE
POTENTIAL FOR COLD AIR DAMMING ACROSS THE INTERIOR INTO TUESDAY.
BIGGEST QUESTION WILL BE IS THERE ENOUGH MOISTURE FOR PRECIP DURING
THIS TIME FRAME. DUE TO A STRENGTHENING LLJ PROVIDING A GOOD SOURCE OF
LIFT ANTICIPATE PRECIP TO DEVELOP AND OVERSPREAD ACROSS SOUTHERN NEW
ENGLAND. IF THIS PLAYS OUT WITH COLD AIR DAMMING AND WARM AIR
ADVECTION...THEN WE COULD SEE FREEZING RAIN/DRIZZLE ACROSS THE I-91
CORRIDOR LATE MONDAY INTO TUESDAY MORNING. DURING THE DAY ON
TUESDAY...GOOD AMOUNT OF WARM AIR WILL PUSH SURFACE TEMPS ABOVE
FREEZING BY THE LATE MORNING ALLOWING FOR ANY PRECIP TO BE MORE OF
THE LIQUID VARIETY AHEAD OF THE CHRISTMAS EVE STORM. HOWEVER
GUIDANCE IS ALWAYS TOO FAST IN SCOURING TEMPS OUT ESP ACROSS THE CT
VALLEY SO WE WILL NEED TO MONITOR THIS CLOSELY...ESP DUE TO LIGHT
WINDS AND THE HIGH IN EASTERN CANADA. A WINTER WX ADVISORY MAY BE
NEEDED FOR THE LIGHT ICING POTENTIAL.

WE COULD ALSO SEE SOME MINOR COASTAL FLOODING CONCERNS ON TUESDAY. SEE
BELOW FOR MORE DETAILS.

WEDNESDAY INTO THURSDAY...HIGH CONFIDENCE IN SYSTEM LOW CONFIDENCE
ON DETAILS.

ANOMALOUS SYSTEM WILL STRENGTHEN OVER THE GREAT LAKES TUESDAY INTO
WEDNESDAY. A SECONDARY SHORTWAVE WILL ROUND THE DEEP TROUGH AND
DEVELOP A SECONDARY LOW PRESSURE ALONG THE COLD FRONT. THIS
SECONDARY LOW WILL STRENGTHEN AND PASS WEST OF SOUTHERN NEW ENGLAND.
THIS SYSTEM WILL CONTINUE TO DEEPEN AS IT MOVES TOWARDS EASTERN
CANADA SWINGING A COLD FRONT ACROSS THE NORTHEAST.

STRONG SOUTHERLY JET OUT AHEAD OF THE FRONT WITH A GULF MOISTURE
CONNECTION WILL IMPACT SOUTHERN NEW ENGLAND ON CHRISTMAS EVE. THIS
STRONG JET WILL YIELD FOR PCPN IN THE LIQUID VARIETY.  PW ANOMALIES
ARE BETWEEN +4 TO +5 STANDARD DEVIATIONS ABOVE NORMAL WHICH IS QUITE
ANOMALOUS FOR THIS TIME OF YEAR. IN FACT CURRENT PWATS ARE PROGGED
ABOVE 1.6 INCHES WITH MODEL QPF OVER 2 INCHES...AT THE VERY LEAST
COULD SEE URBAN AND POOR DRAINAGE FLOODING. LATEST EC EVEN SHOWS
OVER 2.5 INCHES OF QPF...AND WITH THE TROPICAL CONNECTION AND STRONG
SOUTHERLY FLOW COULD SEE HIGHER AMOUNTS DUE TO TOPOGRAPHY
ENHANCEMENTS. RAINFALL RECORDS MAY FALL IF EVERYTHING FALLS INTO
PLACE.

AHEAD OF THE FRONT...SOUTHERN NEW ENGLAND WILL WARM SECTOR WED INTO
THUR MORNING ALLOWING FOR TEMPERATURES TO BE WELL ABOVE AVERAGE. IN
FACT WE MAY BE CLOSE AT BREAKING RECORD HIGH TEMPS IF TEMPS WARM TO
60F OR ABOVE ON CHRISTMAS EVE. SINCE WE WILL BE IN THE WARM
SECTOR...AND SHOWALTERS CLOSE TO ZERO...ISOLATED THUNDER IS STILL
POSSIBLE.

STRONG LOW LEVEL WINDS WILL ALSO BE A CONCERN ESPECIALLY WEDNESDAY
NIGHT. THE ECMWF SHOWS EAST-SOUTHEAST WINDS 30-40 KNOTS ON WEDNESDAY
INCREASING TO 60-75 KNOTS BY WEDNESDAY NIGHT. STRONG DOWNPOURS MAY
OVERCOME THE LOW LEVEL INVERSION AND BRING STRONG GUSTS OF AT LEAST
30-40 KNOTS ESPECIALLY ALONG THE SOUTH COAST. A WIND ADVISORY MAY BE
NEEDED IN SOME AREAS.

CHRISTMAS DAY...MODERATE CONFIDENCE.

AS THE COLD FRONT PASSES THROUGH EARLY CHRISTMAS DAY...THE WEST
WINDS WILL HELP DRY THE AIRMASS ALLOWING FOR PARTLY SUNNY SKIES.
STRONG CAA ON THURSDAY WILL ALLOW DESCENT MIXING. WINDS IN THE SFC-
850 MB LAYER WILL BE 30-40 KNOTS AND POSSIBLY A LITTLE
HIGHER...WHICH WOULD REQUIRE A WIND ADVISORY FOR MUCH OF THE AREA.

FRIDAY-SUNDAY...LOWER CONFIDENCE

WEAK HIGH PRESSURE BUILDS OVER THE AREA FRIDAY INTO SATURDAY. THE
NEXT SHORTWAVE APPROACHES LATE SATURDAY INTO SUNDAY AND SHOULD BRING
INCREASING CLOUDS FROM WEST TO EAST ALONG WITH A CHANCE OF RAIN OR
SNOW SHOWERS MAINLY IN THE AFTERNOON AND AT NIGHT.

&&

.AVIATION /12Z 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.  MAINLY MVFR CONDITIONS
SOUTH OF THE MA TURNPIKE WITH BORDERLINE VFR TO MARGINAL MVFR CIGS
NORTH OF THE PIKE THROUGH TONIGHT.  AN AREA OF SNOW SHOWERS WILL
EXPAND MAINLY ACROSS AREAS SOUTH OF THE PIKE THIS MORNING...BUT A
FEW SNOW SHOWERS WILL STILL AFFECT NORTHERN MA.  VSBYS/CIGS MAY
BRIEFLY DROP TO IFR LEVELS IN NORTHERN CT/RI/SE MA.  PTYPE WILL BE
RAIN SHOWERS ACROSS MOST OF PLYMOUTH COUNTY AND ONTO THE
CAPE/ISLANDS WITH SNOW SHOWERS NORTH AND WEST.  BULK OF PRECIP THIS
MORNING...BUT A FEW LINGERING RAIN/SNOW SHOWERS STILL POSSIBLE THIS
AFTERNOON AND EVENING.

KBOS TERMINAL...MODERATE CONFIDENCE.  A FEW SNOW SHOWERS POSSIBLE
THIS MORNING BUT BULK OF ACTIVITY SHOULD BE SOUTH OF THE TERMINAL.

KBDL TERMINAL...MODERATE CONFIDENCE.  PERIOD OF SNOW SHOWERS THIS
MORNING MAY DROP AN INCH OR TWO OF SNOW.  MVFR CONDITIONS DOMINATE
TODAY....BUT A BRIEF PERIOD OF IFR CONDITIONS ARE POSSIBLE THIS
MORNING IN SNOW SHOWERS.

OUTLOOK...MONDAY THROUGH THURSDAY...MODERATE CONFIDENCE.

MONDAY...MVFR CIGS CONTINUE IN RI/EASTERN MASS IN MARINE EAST FLOW.
VFR IN THE WEST.

TUESDAY...VFR WITH SCATTERED MVFR IN ANY RAIN/SNOW SHOWERS.

WEDNESDAY...CONDITIONS LOWERING TO IFR IN RAIN/HEAVY RAIN. ISOLATED
THUNDERSTORMS POSSIBLE ESPECIALLY WEDNESDAY NIGHT. EAST-SOUTHEAST
SURFACE WINDS MAY GUST TO 35-45 KNOTS. WINDS AT 2000 FEET AGL WILL
REACH 50-60 KNOTS WEDNESDAY AFTERNOON AND EARLY NIGHT CREATING LOW
LEVEL WIND SHEAR CONCERNS.

CHRISTMAS DAY...WEST WIND GUSTING 30-40 KNOTS. CONDITIONS IMPROVING
TO VFR AS THE WIND BRINGS IN COOLER DRIER AIR.

&&

.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.

HIGH PRESSURE ACROSS QUEBEC WILL RESULT IN NORTHEAST WINDS ACROSS
THE WATERS THAT WILL GUST TO BETWEEN 15 AND 20 KNOTS.  THIS WILL
RESULT IN 2 TO 4 FOOT SEAS.  HOWEVER...NO HEADLINES PLANNED AS
CONDITIONS SHOULD REMAIN BELOW SMALL CRAFT ADVISORY THRESHOLDS.

OUTLOOK...MONDAY THROUGH THURSDAY...MODERATE CONFIDENCE

MONDAY...EAST TO NORTHEAST WINDS GUSTING AROUND 15 KNOTS OR LESS.
SEAS WILL HOLD AROUND 3-4 FEET...MAY INCREASE TO 5FT IN NORTHEAST
FLOW AS GUIDANCE MAY BE UNDERDONE.

TUESDAY... INCREASING EAST WINDS WITH FREQUENT GUSTS 25 TO 30 KNOTS.
SEAS WILL BUILD TO 5-6 FEET ON THE EXPOSED WATERS.  A SMALL CRAFT
ADVISORY MAY BE NEEDED.

WEDNESDAY...RAIN WILL BE HEAVY AT TIMES PRODUCING POOR VISIBILITY.
INCREASING SOUTHEAST WINDS 20-25 SUSTAINED AND 40 KNOT GUSTS.  WINDS
SHOULD SHIFT TO SOUTH WEDNESDAY NIGHT AND SOUTHWEST TOWARD THURSDAY
MORNING. RAIN WILL TAPER OFF WITH THE WIND SHIFT TO SOUTHWEST. SEAS
WILL CONTINUE TO BUILD WITH 7-11 FEET HEIGHTS ON THE EXPOSED WATERS.
A GALE WARNING WILL BE NEEDED...WITH A LOW PROB OF A FEW STORM FORCE
GUSTS ACROSS THE EASTERN OUTER WATERS.

CHRISTMAS DAY... WEST SOUTHWEST WINDS WILL CONTINUE TO GUST 35-40
KNOTS...SO A CONTINUED GALE WARNING MAY BE NEEDED. SEAS OF 7-15 FEET
ARE POSSIBLE ON THE EXPOSED WATERS...AND 5 FEET IS POSSIBLE ON SOME
OF THE NEARSHORE WATERS.

&&

.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES WILL OCCUR TUESDAY THROUGH THURSDAY. BREAKING
IT DOWN...ON TUESDAY HIGH TIDE AT BOSTON WILL BE 11.6 FT. THERE WILL
BE ONSHORE FLOW DURING THIS HIGH TIDE ALLOWING FOR MINOR SPLASHOVER.
IF WIND GUSTS INCREASE THEN COULD POSSIBLE SEE MINOR COASTAL
FLOODING.

ON WEDNESDAY...WINDS WILL SWITCH TO A MORE SOUTHEASTERLY FLOW DURING
THE DAY AND INCREASE QUICKLY FROM APPROACHING SYSTEM AND DECENT
PRESSURE FALLS. WEDNESDAY AFTERNOON HIGH TIDE IN BOSTON IS 11.7 FT
AND WITH ANY STRENGTH ON THE EASTERLY WIND FLOW WILL PUSH THE TIDE
OVER. RIGHT NOW BELIEVE MINOR COASTAL FLOODING IS POSSIBLE ALONG THE
EAST COASTLINE.

WEDNESDAY EVENING...THE WIND GOES IN A MORE SOUTHERLY DIRECTION AND
THE TIDE WILL BE INCREASE ACROSS THE SOUTH COAST. HIGH TIDE IN
PROVIDENCE WILL BE 5.2 FT. 925 MB LLJ STRENGTHENS TO 50-60 KTS WHICH
COULD PUSH A DECENT SURGE UP ALONG THE SOUTH COAST DURING THE TIME
OF HIGH TIDE. THINKING THAT MINOR COASTAL FLOODING COULD OCCUR BUT
CANNOT RULE OUT MODERATE ALONG THE SOUTH COAST...ESP IF LLJ
STRENGTHENS EVEN MORE.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...FRANK/DUNTEN
NEAR TERM...FRANK/DUNTEN
SHORT TERM...FRANK
LONG TERM...DUNTEN
AVIATION...FRANK/DUNTEN
MARINE...FRANK/DUNTEN
TIDES/COASTAL FLOODING...STAFF




000
FXUS61 KBOX 211154
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
654 AM EST SUN DEC 21 2014

.SYNOPSIS...
AN AREA OF SNOW SHOWERS WILL AFFECT AREAS MAINLY SOUTH OF THE MA
TURNPIKE THIS MORNING...EXCEPT IT WILL BE MILD ENOUGH FOR RAIN
SHOWERS ACROSS THE FAR SOUTHEAST NEW ENGLAND COAST. WEAK LOW
PRESSURE WILL PASS SOUTH OF NEW ENGLAND BRINGING ANOTHER PERIOD OF
PRECIPITATION MONDAY NIGHT AND TUESDAY. A MUCH STRONGER STORM
PASSING WEST OF NEW ENGLAND WILL BRING HEAVY RAINFALL...GUSTY
WINDS AND COASTAL FLOODING CONCERNS TO THE REGION WEDNESDAY AND
WEDNESDAY NIGHT. DRY BUT VERY WINDY CONDITIONS FOLLOW FOR
CHRISTMAS DAY.

&&

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

700 PM UPDATE...

VERY LITTLE CHANGES TO THE FORECAST AS OVERALL TREND IS ON TRACK
FOR THIS MORNING. RADAR ECHOES LOOK A LITTLE DECEIVING AS SNOW HAS
SPREAD ACROSS A GOOD PORTION OF SOUTHERN NEW ENGLAND PER OBS.
ANTICIPATE MORE WIDE SPREAD BUT LIGHT SNOW OVER THE NEXT HOUR OR
TWO OUTSIDE OF THE COASTAL FRONT...WHICH IS DRAPED OVER GHG-TAN-
UUU.

PREVIOUS DISCUSSION...

APPROACHING SHORTWAVE HAS ALLOWED AN AREA LIGHT SNOW SHOWERS TO
EXPAND SOUTH OF THE MA TURNPIKE VERY EARLY THIS MORNING...BUT A FEW
SNOW SHOWERS DID EXTEND INTO NORTHERN MA.  RADAR IMAGERY ACTUALLY
OVER SHOOTING SOME OF THE ACTIVITY ACROSS NORTHERN CT...BASED ON
OBSERVATIONS.  THE RAIN/SNOW LINE RUNS ROUGHLY FROM NEWPORT...TO
TAUNTON AND JUST NORTH OF MARSHFIELD.  OVERALL...DO NOT EXPECT MUCH
CHANGE IN THE RAIN/SNOW LINE THIS MORNING BASED ON THERMAL PROFILES
AND POSITIONING OF THE COASTAL FRONT.

MAIN UNCERTAINTY IS JUST HOW MUCH SNOW OCCURS THIS MORNING WITH THE
SHORTWAVE MOVING ACROSS CT.  GIVEN THE TRACK OF THE SHORTWAVE...BEST
FORCING WILL BE LOCATED SOUTH OF THE MA TURNPIKE AND ESPECIALLY
ACROSS NORTHERN CT/RI.  WE WILL FORECAST 1 TO 2 INCHES OF SNOW
ACROSS THIS REGION...BUT A FEW ISOLATED 3 INCH AMOUNTS CAN NOT BE
RULED OUT. MEANWHILE...AREAS NORTH OF THE MA TURNPIKE WILL BE
REMOVED FROM THE BEST FORCING...BUT STILL SEE SOME SCATTERED
SHOWERS.  ACCUMS IN THIS AREA LIKELY TO BE A DUSTING TO LESS THAN AN
INCH.

ALSO...SOME OF THE PRECIPITATION CURRENTLY ACROSS SOUTHEAST MA IS
BEING ENHANCED FROM THE COASTAL FRONT.  A LOT OF THIS PRECIP WILL
BE IN THE FORM OF RAIN SHOWERS ACROSS PLYMOUTH AND EVEN INTO
PORTIONS OF BRISTOL COUNTY...POINTS SOUTH AND EAST.  HOWEVER...AT
LEAST THE SLIGHTLY HIGHER TERRAIN OF SOUTHEAST MA SHOULD SEE SNOW
SHOWERS.  WILL HAVE TO KEEP A CLOSE EYE ON IF COASTAL FRONT SHIFTS
SLIGHTLY THIS MORNING.  IT COULD MEAN THE DIFFERENCE BETWEEN AN AREA
GETTING MAINLY RAIN SHOWERS OR PERHAPS AN INCH OR SO OF SNOW.
OVERALL...DO NOT EXPECT THE COASTAL FRONT TO MOVE TOO MUCH THIS
MORNING...BUT JUST A FEW MILES CAN MAKE DIFFERENCE FOR A
PARTICULARLY NEIGHBORHOOD.

BULK OF PRECIPITATION WILL BE THIS MORNING WITH THE SHORTWAVE.
HOWEVER...ENOUGH LOW LEVEL MOISTURE/WEAK LIFT WILL REMAIN THIS
AFTERNOON FOR AT LEAST THIS RISK OF SCATTERED PRECIPITATION AND WILL
MAINTAIN SOME POPS.  HIGH TEMPS MAINLY IN THE 30S.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
TONIGHT...

A RATHER CLOUDY AND RAW NIGHT ACROSS SOUTHERN NEW ENGLAND.  WHILE
THERE IS NOT A SIGNIFICANT SHORTWAVE TO TRIGGER A LOT OF
PRECIPITATION...PLENTY OF LOW LEVEL MOISTURE/WEAK SHALLOW LIFT
REMAINS.  THIS MAY BE ENOUGH TO RESULT IN A FEW RAIN/SNOW SHOWER
FROM TIME TO TIME.  PTYPE...WOULD BE MAINLY SNOW SHOWERS EXCEPT TO
THE SOUTHEAST OF A NEWPORT...TO TAUNTON...TO JUST NORTH OF
MARSHFIELD LINE.  AGAIN...MUCH OF THE NIGHT WILL PROBABLY END UP
DRY...BUT JUST THE RISK FOR A FEW RAIN/SNOW SHOWERS.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
HIGHLIGHTS...

* WEAK SHORTWAVE ON MON NIGHT/TUESDAY COULD BRING WINTRY
  MIX/FREEZING RAIN TO THE INTERIOR
* ANOMALOUS SYSTEM ACROSS THE GREAT LAKES WILL BRING HEAVY
  RAIN...GUSTY WINDS AND COASTAL FLOODING CONCERNS AROUND CHRISTMAS
  EVE
* BLUSTERY BUT AIRMASS WILL BE DRYING OUT ON CHRISTMAS DAY

OVERVIEW...

THE MODELS AND ENSEMBLES OFFER A REASONABLY SIMILAR AND PREDICTABLE
LARGER SCALE MID TO UPPER LEVEL PATTERN EVOLUTION FOR MUCH OF THE
UPCOMING WEEK. THIS ACTIVE FLOW REGIME DEVELOPS SEVERAL MID-UPPER
LEVEL TROUGH AND ASSOCIATED/UNSETTLING LEAD SURFACE LOW/FRONTAL
SYSTEMS AND PCPN SWATHS PROGRESS STEADILY ACROSS THE LOWER 48. THE
FIRST AMPLIFIED/DEEP LEAD SYSTEM WORKS ACROSS THE ERN/NERN US INTO
ERN CANADA CHRISTMAS EVE INTO CHRISTMAS ALLOWING FOR A MOIST/WARMED
AIRMASS IN ADVANCE OF FRONTAL APPROACH WITH HEAVIEST LEAD QPF
POTENTIAL OVER NEW ENGLAND. BIGGEST QUESTION IS THE EVOLUTION OF THE
SECONDARY LOW PRESSURE SYSTEM. 00Z GUIDANCE HAS BACKED OFF ON THE
STRENGTH OF THE LOW AND IS HAVING ISSUES ON HOW TO HANDLE ITS
EVOLUTION. THE EC AND GFS HAVE SLOWED DOWN THE SYSTEM SLIGHTLY WITH
THE EC HAVING MORE OF A NEGATIVE TROUGH VS THE GFS. BELIEVE THE
UKMET IS A GOOD COMPROMISE AT IS WAS THE FIRST DETERMINISTIC
GUIDANCE ON TAMPERING DOWN THE FIRST MAIN LOW...WHILE THE CMC IS OUT
TO LUNCH. REGARDLESS THIS IS A VERY ANOMALOUS SYSTEM THAT IS ABOUT 4
STANDARD DEVIATIONS AWAY.

A SECONDARY SYSTEM DEEPENS ACROSS THE FOUR CORNERS ON FRIDAY AND
WITH THE STUBBORN TROUGH OVER THE CENTRAL U.S...IT WILL PUSH A
SYSTEM TOWARDS SOUTHERN NEW ENGLAND BY SUNDAY. THIS SYSTEM MAY
SUPPORT A MODEST SWATH OF OVERRUNNING SNOW OVER SOUTHERN NEW
ENGLAND.

DETAILS...

MONDAY INTO TUESDAY...MODERATE CONFIDENCE.

A WEAK WAVE OF LOW PRESSURE DEVELOPS ALONG THE SOUTHEAST COAST
MONDAY...AND WILL BE ON A DEVELOPING WARM FRONTAL BOUNDARY. THIS LOW
REMAINS WEAK AS THE WARM FRONT MOVES SLOWLY NORTH MONDAY NIGHT INTO
TUESDAY. APPEARS THAT THERE IS DECENT WARM ADVECTION AHEAD OF THIS
WAVE. SEVERAL HI-RES GUIDANCE MODELS SHOW THAT THERE IS THE
POTENTIAL FOR COLD AIR DAMMING ACROSS THE INTERIOR INTO TUESDAY.
BIGGEST QUESTION WILL BE IS THERE ENOUGH MOISTURE FOR PRECIP DURING
THIS TIME FRAME. DUE TO A STRENGTHENING LLJ PROVIDING A GOOD SOURCE OF
LIFT ANTICIPATE PRECIP TO DEVELOP AND OVERSPREAD ACROSS SOUTHERN NEW
ENGLAND. IF THIS PLAYS OUT WITH COLD AIR DAMMING AND WARM AIR
ADVECTION...THEN WE COULD SEE FREEZING RAIN/DRIZZLE ACROSS THE I-91
CORRIDOR LATE MONDAY INTO TUESDAY MORNING. DURING THE DAY ON
TUESDAY...GOOD AMOUNT OF WARM AIR WILL PUSH SURFACE TEMPS ABOVE
FREEZING BY THE LATE MORNING ALLOWING FOR ANY PRECIP TO BE MORE OF
THE LIQUID VARIETY AHEAD OF THE CHRISTMAS EVE STORM. HOWEVER
GUIDANCE IS ALWAYS TOO FAST IN SCOURING TEMPS OUT ESP ACROSS THE CT
VALLEY SO WE WILL NEED TO MONITOR THIS CLOSELY...ESP DUE TO LIGHT
WINDS AND THE HIGH IN EASTERN CANADA. A WINTER WX ADVISORY MAY BE
NEEDED FOR THE LIGHT ICING POTENTIAL.

WE COULD ALSO SEE SOME MINOR COASTAL FLOODING CONCERNS ON TUESDAY. SEE
BELOW FOR MORE DETAILS.

WEDNESDAY INTO THURSDAY...HIGH CONFIDENCE IN SYSTEM LOW CONFIDENCE
ON DETAILS.

ANOMALOUS SYSTEM WILL STRENGTHEN OVER THE GREAT LAKES TUESDAY INTO
WEDNESDAY. A SECONDARY SHORTWAVE WILL ROUND THE DEEP TROUGH AND
DEVELOP A SECONDARY LOW PRESSURE ALONG THE COLD FRONT. THIS
SECONDARY LOW WILL STRENGTHEN AND PASS WEST OF SOUTHERN NEW ENGLAND.
THIS SYSTEM WILL CONTINUE TO DEEPEN AS IT MOVES TOWARDS EASTERN
CANADA SWINGING A COLD FRONT ACROSS THE NORTHEAST.

STRONG SOUTHERLY JET OUT AHEAD OF THE FRONT WITH A GULF MOISTURE
CONNECTION WILL IMPACT SOUTHERN NEW ENGLAND ON CHRISTMAS EVE. THIS
STRONG JET WILL YIELD FOR PCPN IN THE LIQUID VARIETY.  PW ANOMALIES
ARE BETWEEN +4 TO +5 STANDARD DEVIATIONS ABOVE NORMAL WHICH IS QUITE
ANOMALOUS FOR THIS TIME OF YEAR. IN FACT CURRENT PWATS ARE PROGGED
ABOVE 1.6 INCHES WITH MODEL QPF OVER 2 INCHES...AT THE VERY LEAST
COULD SEE URBAN AND POOR DRAINAGE FLOODING. LATEST EC EVEN SHOWS
OVER 2.5 INCHES OF QPF...AND WITH THE TROPICAL CONNECTION AND STRONG
SOUTHERLY FLOW COULD SEE HIGHER AMOUNTS DUE TO TOPOGRAPHY
ENHANCEMENTS. RAINFALL RECORDS MAY FALL IF EVERYTHING FALLS INTO
PLACE.

AHEAD OF THE FRONT...SOUTHERN NEW ENGLAND WILL WARM SECTOR WED INTO
THUR MORNING ALLOWING FOR TEMPERATURES TO BE WELL ABOVE AVERAGE. IN
FACT WE MAY BE CLOSE AT BREAKING RECORD HIGH TEMPS IF TEMPS WARM TO
60F OR ABOVE ON CHRISTMAS EVE. SINCE WE WILL BE IN THE WARM
SECTOR...AND SHOWALTERS CLOSE TO ZERO...ISOLATED THUNDER IS STILL
POSSIBLE.

STRONG LOW LEVEL WINDS WILL ALSO BE A CONCERN ESPECIALLY WEDNESDAY
NIGHT. THE ECMWF SHOWS EAST-SOUTHEAST WINDS 30-40 KNOTS ON WEDNESDAY
INCREASING TO 60-75 KNOTS BY WEDNESDAY NIGHT. STRONG DOWNPOURS MAY
OVERCOME THE LOW LEVEL INVERSION AND BRING STRONG GUSTS OF AT LEAST
30-40 KNOTS ESPECIALLY ALONG THE SOUTH COAST. A WIND ADVISORY MAY BE
NEEDED IN SOME AREAS.

CHRISTMAS DAY...MODERATE CONFIDENCE.

AS THE COLD FRONT PASSES THROUGH EARLY CHRISTMAS DAY...THE WEST
WINDS WILL HELP DRY THE AIRMASS ALLOWING FOR PARTLY SUNNY SKIES.
STRONG CAA ON THURSDAY WILL ALLOW DESCENT MIXING. WINDS IN THE SFC-
850 MB LAYER WILL BE 30-40 KNOTS AND POSSIBLY A LITTLE
HIGHER...WHICH WOULD REQUIRE A WIND ADVISORY FOR MUCH OF THE AREA.

FRIDAY-SUNDAY...LOWER CONFIDENCE

WEAK HIGH PRESSURE BUILDS OVER THE AREA FRIDAY INTO SATURDAY. THE
NEXT SHORTWAVE APPROACHES LATE SATURDAY INTO SUNDAY AND SHOULD BRING
INCREASING CLOUDS FROM WEST TO EAST ALONG WITH A CHANCE OF RAIN OR
SNOW SHOWERS MAINLY IN THE AFTERNOON AND AT NIGHT.

&&

.AVIATION /12Z 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.  MAINLY MVFR CONDITIONS
SOUTH OF THE MA TURNPIKE WITH BORDERLINE VFR TO MARGINAL MVFR CIGS
NORTH OF THE PIKE THROUGH TONIGHT.  AN AREA OF SNOW SHOWERS WILL
EXPAND MAINLY ACROSS AREAS SOUTH OF THE PIKE THIS MORNING...BUT A
FEW SNOW SHOWERS WILL STILL AFFECT NORTHERN MA.  VSBYS/CIGS MAY
BRIEFLY DROP TO IFR LEVELS IN NORTHERN CT/RI/SE MA.  PTYPE WILL BE
RAIN SHOWERS ACROSS MOST OF PLYMOUTH COUNTY AND ONTO THE
CAPE/ISLANDS WITH SNOW SHOWERS NORTH AND WEST.  BULK OF PRECIP THIS
MORNING...BUT A FEW LINGERING RAIN/SNOW SHOWERS STILL POSSIBLE THIS
AFTERNOON AND EVENING.

KBOS TERMINAL...MODERATE CONFIDENCE.  A FEW SNOW SHOWERS POSSIBLE
THIS MORNING BUT BULK OF ACTIVITY SHOULD BE SOUTH OF THE TERMINAL.

KBDL TERMINAL...MODERATE CONFIDENCE.  PERIOD OF SNOW SHOWERS THIS
MORNING MAY DROP AN INCH OR TWO OF SNOW.  MVFR CONDITIONS DOMINATE
TODAY....BUT A BRIEF PERIOD OF IFR CONDITIONS ARE POSSIBLE THIS
MORNING IN SNOW SHOWERS.

OUTLOOK...MONDAY THROUGH THURSDAY...MODERATE CONFIDENCE.

MONDAY...MVFR CIGS CONTINUE IN RI/EASTERN MASS IN MARINE EAST FLOW.
VFR IN THE WEST.

TUESDAY...VFR WITH SCATTERED MVFR IN ANY RAIN/SNOW SHOWERS.

WEDNESDAY...CONDITIONS LOWERING TO IFR IN RAIN/HEAVY RAIN. ISOLATED
THUNDERSTORMS POSSIBLE ESPECIALLY WEDNESDAY NIGHT. EAST-SOUTHEAST
SURFACE WINDS MAY GUST TO 35-45 KNOTS. WINDS AT 2000 FEET AGL WILL
REACH 50-60 KNOTS WEDNESDAY AFTERNOON AND EARLY NIGHT CREATING LOW
LEVEL WIND SHEAR CONCERNS.

CHRISTMAS DAY...WEST WIND GUSTING 30-40 KNOTS. CONDITIONS IMPROVING
TO VFR AS THE WIND BRINGS IN COOLER DRIER AIR.

&&

.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.

HIGH PRESSURE ACROSS QUEBEC WILL RESULT IN NORTHEAST WINDS ACROSS
THE WATERS THAT WILL GUST TO BETWEEN 15 AND 20 KNOTS.  THIS WILL
RESULT IN 2 TO 4 FOOT SEAS.  HOWEVER...NO HEADLINES PLANNED AS
CONDITIONS SHOULD REMAIN BELOW SMALL CRAFT ADVISORY THRESHOLDS.

OUTLOOK...MONDAY THROUGH THURSDAY...MODERATE CONFIDENCE

MONDAY...EAST TO NORTHEAST WINDS GUSTING AROUND 15 KNOTS OR LESS.
SEAS WILL HOLD AROUND 3-4 FEET...MAY INCREASE TO 5FT IN NORTHEAST
FLOW AS GUIDANCE MAY BE UNDERDONE.

TUESDAY... INCREASING EAST WINDS WITH FREQUENT GUSTS 25 TO 30 KNOTS.
SEAS WILL BUILD TO 5-6 FEET ON THE EXPOSED WATERS.  A SMALL CRAFT
ADVISORY MAY BE NEEDED.

WEDNESDAY...RAIN WILL BE HEAVY AT TIMES PRODUCING POOR VISIBILITY.
INCREASING SOUTHEAST WINDS 20-25 SUSTAINED AND 40 KNOT GUSTS.  WINDS
SHOULD SHIFT TO SOUTH WEDNESDAY NIGHT AND SOUTHWEST TOWARD THURSDAY
MORNING. RAIN WILL TAPER OFF WITH THE WIND SHIFT TO SOUTHWEST. SEAS
WILL CONTINUE TO BUILD WITH 7-11 FEET HEIGHTS ON THE EXPOSED WATERS.
A GALE WARNING WILL BE NEEDED...WITH A LOW PROB OF A FEW STORM FORCE
GUSTS ACROSS THE EASTERN OUTER WATERS.

CHRISTMAS DAY... WEST SOUTHWEST WINDS WILL CONTINUE TO GUST 35-40
KNOTS...SO A CONTINUED GALE WARNING MAY BE NEEDED. SEAS OF 7-15 FEET
ARE POSSIBLE ON THE EXPOSED WATERS...AND 5 FEET IS POSSIBLE ON SOME
OF THE NEARSHORE WATERS.

&&

.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES WILL OCCUR TUESDAY THROUGH THURSDAY. BREAKING
IT DOWN...ON TUESDAY HIGH TIDE AT BOSTON WILL BE 11.6 FT. THERE WILL
BE ONSHORE FLOW DURING THIS HIGH TIDE ALLOWING FOR MINOR SPLASHOVER.
IF WIND GUSTS INCREASE THEN COULD POSSIBLE SEE MINOR COASTAL
FLOODING.

ON WEDNESDAY...WINDS WILL SWITCH TO A MORE SOUTHEASTERLY FLOW DURING
THE DAY AND INCREASE QUICKLY FROM APPROACHING SYSTEM AND DECENT
PRESSURE FALLS. WEDNESDAY AFTERNOON HIGH TIDE IN BOSTON IS 11.7 FT
AND WITH ANY STRENGTH ON THE EASTERLY WIND FLOW WILL PUSH THE TIDE
OVER. RIGHT NOW BELIEVE MINOR COASTAL FLOODING IS POSSIBLE ALONG THE
EAST COASTLINE.

WEDNESDAY EVENING...THE WIND GOES IN A MORE SOUTHERLY DIRECTION AND
THE TIDE WILL BE INCREASE ACROSS THE SOUTH COAST. HIGH TIDE IN
PROVIDENCE WILL BE 5.2 FT. 925 MB LLJ STRENGTHENS TO 50-60 KTS WHICH
COULD PUSH A DECENT SURGE UP ALONG THE SOUTH COAST DURING THE TIME
OF HIGH TIDE. THINKING THAT MINOR COASTAL FLOODING COULD OCCUR BUT
CANNOT RULE OUT MODERATE ALONG THE SOUTH COAST...ESP IF LLJ
STRENGTHENS EVEN MORE.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...FRANK/DUNTEN
NEAR TERM...FRANK/DUNTEN
SHORT TERM...FRANK
LONG TERM...DUNTEN
AVIATION...FRANK/DUNTEN
MARINE...FRANK/DUNTEN
TIDES/COASTAL FLOODING...STAFF




000
FXUS61 KBOX 210916
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
416 AM EST SUN DEC 21 2014

.SYNOPSIS...
AN AREA OF SNOW SHOWERS WILL AFFECT AREAS MAINLY SOUTH OF THE MA
TURNPIKE THIS MORNING...EXCEPT IT WILL BE MILD ENOUGH FOR RAIN
SHOWERS ACROSS THE FAR SOUTHEAST NEW ENGLAND COAST. WEAK LOW
PRESSURE WILL PASS SOUTH OF NEW ENGLAND BRINGING ANOTHER PERIOD OF
PRECIPITATION MONDAY NIGHT AND TUESDAY. A MUCH STRONGER STORM
PASSING WEST OF NEW ENGLAND WILL BRING HEAVY RAINFALL...GUSTY
WINDS AND COASTAL FLOODING CONCERNS TO THE REGION WEDNESDAY AND
WEDNESDAY NIGHT. DRY BUT VERY WINDY CONDITIONS FOLLOW FOR
CHRISTMAS DAY.

&&

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

4 AM UPDATE...

APPROACHING SHORTWAVE HAS ALLOWED AN AREA LIGHT SNOW SHOWERS TO
EXPAND SOUTH OF THE MA TURNPIKE VERY EARLY THIS MORNING...BUT A FEW
SNOW SHOWERS DID EXTEND INTO NORTHERN MA.  RADAR IMAGERY ACTUALLY
OVER SHOOTING SOME OF THE ACTIVITY ACROSS NORTHERN CT...BASED ON
OBSERVATIONS.  THE RAIN/SNOW LINE RUNS ROUGHLY FROM NEWPORT...TO
TAUNTON AND JUST NORTH OF MARSHFIELD.  OVERALL...DO NOT EXPECT MUCH
CHANGE IN THE RAIN/SNOW LINE THIS MORNING BASED ON THERMAL PROFILES
AND POSITIONING OF THE COASTAL FRONT.

MAIN UNCERTAINTY IS JUST HOW MUCH SNOW OCCURS THIS MORNING WITH THE
SHORTWAVE MOVING ACROSS CT.  GIVEN THE TRACK OF THE SHORTWAVE...BEST
FORCING WILL BE LOCATED SOUTH OF THE MA TURNPIKE AND ESPECIALLY
ACROSS NORTHERN CT/RI.  WE WILL FORECAST 1 TO 2 INCHES OF SNOW
ACROSS THIS REGION...BUT A FEW ISOLATED 3 INCH AMOUNTS CAN NOT BE
RULED OUT. MEANWHILE...AREAS NORTH OF THE MA TURNPIKE WILL BE
REMOVED FROM THE BEST FORCING...BUT STILL SEE SOME SCATTERED
SHOWERS.  ACCUMS IN THIS AREA LIKELY TO BE A DUSTING TO LESS THAN AN
INCH.

ALSO...SOME OF THE PRECIPITATION CURRENTLY ACROSS SOUTHEAST MA IS
BEING ENHANCED FROM THE COASTAL FRONT.  A LOT OF THIS PRECIP WILL
BE IN THE FORM OF RAIN SHOWERS ACROSS PLYMOUTH AND EVEN INTO
PORTIONS OF BRISTOL COUNTY...POINTS SOUTH AND EAST.  HOWEVER...AT
LEAST THE SLIGHTLY HIGHER TERRAIN OF SOUTHEAST MA SHOULD SEE SNOW
SHOWERS.  WILL HAVE TO KEEP A CLOSE EYE ON IF COASTAL FRONT SHIFTS
SLIGHTLY THIS MORNING.  IT COULD MEAN THE DIFFERENCE BETWEEN AN AREA
GETTING MAINLY RAIN SHOWERS OR PERHAPS AN INCH OR SO OF SNOW.
OVERALL...DO NOT EXPECT THE COASTAL FRONT TO MOVE TOO MUCH THIS
MORNING...BUT JUST A FEW MILES CAN MAKE DIFFERENCE FOR A
PARTICULARLY NEIGHBORHOOD.

BULK OF PRECIPITATION WILL BE THIS MORNING WITH THE SHORTWAVE.
HOWEVER...ENOUGH LOW LEVEL MOISTURE/WEAK LIFT WILL REMAIN THIS
AFTERNOON FOR AT LEAST THIS RISK OF SCATTERED PRECIPITATION AND WILL
MAINTAIN SOME POPS.  HIGH TEMPS MAINLY IN THE 30S.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...

TONIGHT...

A RATHER CLOUDY AND RAW NIGHT ACROSS SOUTHERN NEW ENGLAND.  WHILE
THERE IS NOT A SIGNIFICANT SHORTWAVE TO TRIGGER A LOT OF
PRECIPITATION...PLENTY OF LOW LEVEL MOISTURE/WEAK SHALLOW LIFT
REMAINS.  THIS MAY BE ENOUGH TO RESULT IN A FEW RAIN/SNOW SHOWER
FROM TIME TO TIME.  PTYPE...WOULD BE MAINLY SNOW SHOWERS EXCEPT TO
THE SOUTHEAST OF A NEWPORT...TO TAUNTON...TO JUST NORTH OF
MARSHFIELD LINE.  AGAIN...MUCH OF THE NIGHT WILL PROBABLY END UP
DRY...BUT JUST THE RISK FOR A FEW RAIN/SNOW SHOWERS.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...

HIGHLIGHTS...

* WEAK SHORTWAVE ON MON NIGHT/TUESDAY COULD BRING WINTRY
  MIX/FREEZING RAIN TO THE INTERIOR
* ANOMALOUS SYSTEM ACROSS THE GREAT LAKES WILL BRING HEAVY
  RAIN...GUSTY WINDS AND COASTAL FLOODING CONCERNS AROUND CHRISTMAS
  EVE
* BLUSTERY BUT AIRMASS WILL BE DRYING OUT ON CHRISTMAS DAY

OVERVIEW...

THE MODELS AND ENSEMBLES OFFER A REASONABLY SIMILAR AND PREDICTABLE
LARGER SCALE MID TO UPPER LEVEL PATTERN EVOLUTION FOR MUCH OF THE
UPCOMING WEEK. THIS ACTIVE FLOW REGIME DEVELOPS SEVERAL MID-UPPER
LEVEL TROUGH AND ASSOCIATED/UNSETTLING LEAD SURFACE LOW/FRONTAL
SYSTEMS AND PCPN SWATHS PROGRESS STEADILY ACROSS THE LOWER 48. THE
FIRST AMPLIFIED/DEEP LEAD SYSTEM WORKS ACROSS THE ERN/NERN US INTO
ERN CANADA CHRISTMAS EVE INTO CHRISTMAS ALLOWING FOR A MOIST/WARMED
AIRMASS IN ADVANCE OF FRONTAL APPROACH WITH HEAVIEST LEAD QPF
POTENTIAL OVER NEW ENGLAND. BIGGEST QUESTION IS THE EVOLUTION OF THE
SECONDARY LOW PRESSURE SYSTEM. 00Z GUIDANCE HAS BACKED OFF ON THE
STRENGTH OF THE LOW AND IS HAVING ISSUES ON HOW TO HANDLE ITS
EVOLUTION. THE EC AND GFS HAVE SLOWED DOWN THE SYSTEM SLIGHTLY WITH
THE EC HAVING MORE OF A NEGATIVE TROUGH VS THE GFS. BELIEVE THE
UKMET IS A GOOD COMPROMISE AT IS WAS THE FIRST DETERMINISTIC
GUIDANCE ON TAMPERING DOWN THE FIRST MAIN LOW...WHILE THE CMC IS OUT
TO LUNCH. REGARDLESS THIS IS A VERY ANOMALOUS SYSTEM THAT IS ABOUT 4
STANDARD DEVIATIONS AWAY.

A SECONDARY SYSTEM DEEPENS ACROSS THE FOUR CORNERS ON FRIDAY AND
WITH THE STUBBORN TROUGH OVER THE CENTRAL U.S...IT WILL PUSH A
SYSTEM TOWARDS SOUTHERN NEW ENGLAND BY SUNDAY. THIS SYSTEM MAY
SUPPORT A MODEST SWATH OF OVERRUNNING SNOW OVER SOUTHERN NEW
ENGLAND.

DETAILS...

MONDAY INTO TUESDAY...MODERATE CONFIDENCE.

A WEAK WAVE OF LOW PRESSURE DEVELOPS ALONG THE SOUTHEAST COAST
MONDAY...AND WILL BE ON A DEVELOPING WARM FRONTAL BOUNDARY. THIS LOW
REMAINS WEAK AS THE WARM FRONT MOVES SLOWLY NORTH MONDAY NIGHT INTO
TUESDAY. APPEARS THAT THERE IS DECENT WARM ADVECTION AHEAD OF THIS
WAVE. SEVERAL HI-RES GUIDANCE MODELS SHOW THAT THERE IS THE
POTENTIAL FOR COLD AIR DAMMING ACROSS THE INTERIOR INTO TUESDAY.
BIGGEST QUESTION WILL BE IS THERE ENOUGH MOISTURE FOR PRECIP DURING
THIS TIME FRAME. DUE TO A STRENGTHENING LLJ PROVIDING A GOOD SOURCE OF
LIFT ANTICIPATE PRECIP TO DEVELOP AND OVERSPREAD ACROSS SOUTHERN NEW
ENGLAND. IF THIS PLAYS OUT WITH COLD AIR DAMMING AND WARM AIR
ADVECTION...THEN WE COULD SEE FREEZING RAIN/DRIZZLE ACROSS THE I-91
CORRIDOR LATE MONDAY INTO TUESDAY MORNING. DURING THE DAY ON
TUESDAY...GOOD AMOUNT OF WARM AIR WILL PUSH SURFACE TEMPS ABOVE
FREEZING BY THE LATE MORNING ALLOWING FOR ANY PRECIP TO BE MORE OF
THE LIQUID VARIETY AHEAD OF THE CHRISTMAS EVE STORM. HOWEVER
GUIDANCE IS ALWAYS TOO FAST IN SCOURING TEMPS OUT ESP ACROSS THE CT
VALLEY SO WE WILL NEED TO MONITOR THIS CLOSELY...ESP DUE TO LIGHT
WINDS AND THE HIGH IN EASTERN CANADA. A WINTER WX ADVISORY MAY BE
NEEDED FOR THE LIGHT ICING POTENTIAL.

WE COULD ALSO SEE SOME MINOR COASTAL FLOODING CONCERNS ON TUESDAY. SEE
BELOW FOR MORE DETAILS.

WEDNESDAY INTO THURSDAY...HIGH CONFIDENCE IN SYSTEM LOW CONFIDENCE
ON DETAILS.

ANOMALOUS SYSTEM WILL STRENGTHEN OVER THE GREAT LAKES TUESDAY INTO
WEDNESDAY. A SECONDARY SHORTWAVE WILL ROUND THE DEEP TROUGH AND
DEVELOP A SECONDARY LOW PRESSURE ALONG THE COLD FRONT. THIS
SECONDARY LOW WILL STRENGTHEN AND PASS WEST OF SOUTHERN NEW ENGLAND.
THIS SYSTEM WILL CONTINUE TO DEEPEN AS IT MOVES TOWARDS EASTERN
CANADA SWINGING A COLD FRONT ACROSS THE NORTHEAST.

STRONG SOUTHERLY JET OUT AHEAD OF THE FRONT WITH A GULF MOISTURE
CONNECTION WILL IMPACT SOUTHERN NEW ENGLAND ON CHRISTMAS EVE. THIS
STRONG JET WILL YIELD FOR PCPN IN THE LIQUID VARIETY.  PW ANOMALIES
ARE BETWEEN +4 TO +5 STANDARD DEVIATIONS ABOVE NORMAL WHICH IS QUITE
ANOMALOUS FOR THIS TIME OF YEAR. IN FACT CURRENT PWATS ARE PROGGED
ABOVE 1.6 INCHES WITH MODEL QPF OVER 2 INCHES...AT THE VERY LEAST
COULD SEE URBAN AND POOR DRAINAGE FLOODING. LATEST EC EVEN SHOWS
OVER 2.5 INCHES OF QPF...AND WITH THE TROPICAL CONNECTION AND STRONG
SOUTHERLY FLOW COULD SEE HIGHER AMOUNTS DUE TO TOPOGRAPHY
ENHANCEMENTS. RAINFALL RECORDS MAY FALL IF EVERYTHING FALLS INTO
PLACE.

AHEAD OF THE FRONT...SOUTHERN NEW ENGLAND WILL WARM SECTOR WED INTO
THUR MORNING ALLOWING FOR TEMPERATURES TO BE WELL ABOVE AVERAGE. IN
FACT WE MAY BE CLOSE AT BREAKING RECORD HIGH TEMPS IF TEMPS WARM TO
60F OR ABOVE ON CHRISTMAS EVE. SINCE WE WILL BE IN THE WARM
SECTOR...AND SHOWALTERS CLOSE TO ZERO...ISOLATED THUNDER IS STILL
POSSIBLE.

STRONG LOW LEVEL WINDS WILL ALSO BE A CONCERN ESPECIALLY WEDNESDAY
NIGHT. THE ECMWF SHOWS EAST-SOUTHEAST WINDS 30-40 KNOTS ON WEDNESDAY
INCREASING TO 60-75 KNOTS BY WEDNESDAY NIGHT. STRONG DOWNPOURS MAY
OVERCOME THE LOW LEVEL INVERSION AND BRING STRONG GUSTS OF AT LEAST
30-40 KNOTS ESPECIALLY ALONG THE SOUTH COAST. A WIND ADVISORY MAY BE
NEEDED IN SOME AREAS.

CHRISTMAS DAY...MODERATE CONFIDENCE.

AS THE COLD FRONT PASSES THROUGH EARLY CHRISTMAS DAY...THE WEST
WINDS WILL HELP DRY THE AIRMASS ALLOWING FOR PARTLY SUNNY SKIES.
STRONG CAA ON THURSDAY WILL ALLOW DESCENT MIXING. WINDS IN THE SFC-
850 MB LAYER WILL BE 30-40 KNOTS AND POSSIBLY A LITTLE
HIGHER...WHICH WOULD REQUIRE A WIND ADVISORY FOR MUCH OF THE AREA.

FRIDAY-SUNDAY...LOWER CONFIDENCE

WEAK HIGH PRESSURE BUILDS OVER THE AREA FRIDAY INTO SATURDAY. THE
NEXT SHORTWAVE APPROACHES LATE SATURDAY INTO SUNDAY AND SHOULD BRING
INCREASING CLOUDS FROM WEST TO EAST ALONG WITH A CHANCE OF RAIN OR
SNOW SHOWERS MAINLY IN THE AFTERNOON AND AT NIGHT.

&&

.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.  MAINLY MVFR CONDITIONS
SOUTH OF THE MA TURNPIKE WITH BORDERLINE VFR TO MARGINAL MVFR CIGS
NORTH OF THE PIKE THROUGH TONIGHT.  AN AREA OF SNOW SHOWERS WILL
EXPAND MAINLY ACROSS AREAS SOUTH OF THE PIKE THIS MORNING...BUT A
FEW SNOW SHOWERS WILL STILL AFFECT NORTHERN MA.  VSBYS/CIGS MAY
BRIEFLY DROP TO IFR LEVELS IN NORTHERN CT/RI/SE MA.  PTYPE WILL BE
RAIN SHOWERS ACROSS MOST OF PLYMOUTH COUNTY AND ONTO THE
CAPE/ISLANDS WITH SNOW SHOWERS NORTH AND WEST.  BULK OF PRECIP THIS
MORNING...BUT A FEW LINGERING RAIN/SNOW SHOWERS STILL POSSIBLE THIS
AFTERNOON AND EVENING.

KBOS TERMINAL...MODERATE CONFIDENCE.  A FEW SNOW SHOWERS POSSIBLE
THIS MORNING BUT BULK OF ACTIVITY SHOULD BE SOUTH OF THE TERMINAL.

KBDL TERMINAL...MODERATE CONFIDENCE.  PERIOD OF SNOW SHOWERS THIS
MORNING MAY DROP AN INCH OR TWO OF SNOW.  MVFR CONDITIONS DOMINATE
TODAY....BUT A BRIEF PERIOD OF IFR CONDITIONS ARE POSSIBLE THIS
MORNING IN SNOW SHOWERS.

OUTLOOK...MONDAY THROUGH THURSDAY...MODERATE CONFIDENCE.

MONDAY...MVFR CIGS CONTINUE IN RI/EASTERN MASS IN MARINE EAST FLOW.
VFR IN THE WEST.

TUESDAY...VFR WITH SCATTERED MVFR IN ANY RAIN/SNOW SHOWERS.

WEDNESDAY...CONDITIONS LOWERING TO IFR IN RAIN/HEAVY RAIN. ISOLATED
THUNDERSTORMS POSSIBLE ESPECIALLY WEDNESDAY NIGHT. EAST-SOUTHEAST
SURFACE WINDS MAY GUST TO 35-45 KNOTS. WINDS AT 2000 FEET AGL WILL
REACH 50-60 KNOTS WEDNESDAY AFTERNOON AND EARLY NIGHT CREATING LOW
LEVEL WIND SHEAR CONCERNS.

CHRISTMAS DAY...WEST WIND GUSTING 30-40 KNOTS. CONDITIONS IMPROVING
TO VFR AS THE WIND BRINGS IN COOLER DRIER AIR.

&&

.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.

HIGH PRESSURE ACROSS QUEBEC WILL RESULT IN NORTHEAST WINDS ACROSS
THE WATERS THAT WILL GUST TO BETWEEN 15 AND 20 KNOTS.  THIS WILL
RESULT IN 2 TO 4 FOOT SEAS.  HOWEVER...NO HEADLINES PLANNED AS
CONDITIONS SHOULD REMAIN BELOW SMALL CRAFT ADVISORY THRESHOLDS.

OUTLOOK...MONDAY THROUGH THURSDAY...MODERATE CONFIDENCE

MONDAY...EAST TO NORTHEAST WINDS GUSTING AROUND 15 KNOTS OR LESS.
SEAS WILL HOLD AROUND 3-4 FEET...MAY INCREASE TO 5FT IN NORTHEAST
FLOW AS GUIDANCE MAY BE UNDERDONE.

TUESDAY... INCREASING EAST WINDS WITH FREQUENT GUSTS 25 TO 30 KNOTS.
SEAS WILL BUILD TO 5-6 FEET ON THE EXPOSED WATERS.  A SMALL CRAFT
ADVISORY MAY BE NEEDED.

WEDNESDAY...RAIN WILL BE HEAVY AT TIMES PRODUCING POOR VISIBILITY.
INCREASING SOUTHEAST WINDS 20-25 SUSTAINED AND 40 KNOT GUSTS.  WINDS
SHOULD SHIFT TO SOUTH WEDNESDAY NIGHT AND SOUTHWEST TOWARD THURSDAY
MORNING. RAIN WILL TAPER OFF WITH THE WIND SHIFT TO SOUTHWEST. SEAS
WILL CONTINUE TO BUILD WITH 7-11 FEET HEIGHTS ON THE EXPOSED WATERS.
A GALE WARNING WILL BE NEEDED...WITH A LOW PROB OF A FEW STORM FORCE
GUSTS ACROSS THE EASTERN OUTER WATERS.

CHRISTMAS DAY... WEST SOUTHWEST WINDS WILL CONTINUE TO GUST 35-40
KNOTS...SO A CONTINUED GALE WARNING MAY BE NEEDED. SEAS OF 7-15 FEET
ARE POSSIBLE ON THE EXPOSED WATERS...AND 5 FEET IS POSSIBLE ON SOME
OF THE NEARSHORE WATERS.

&&

.TIDES/COASTAL FLOODING...

HIGH ASTRONOMICAL TIDES WILL OCCUR TUESDAY THROUGH THURSDAY. BREAKING
IT DOWN...ON TUESDAY HIGH TIDE AT BOSTON WILL BE 11.6 FT. THERE WILL
BE ONSHORE FLOW DURING THIS HIGH TIDE ALLOWING FOR MINOR SPLASHOVER.
IF WIND GUSTS INCREASE THEN COULD POSSIBLE SEE MINOR COASTAL
FLOODING.

ON WEDNESDAY...WINDS WILL SWITCH TO A MORE SOUTHEASTERLY FLOW DURING
THE DAY AND INCREASE QUICKLY FROM APPROACHING SYSTEM AND DECENT
PRESSURE FALLS. WEDNESDAY AFTERNOON HIGH TIDE IN BOSTON IS 11.7 FT
AND WITH ANY STRENGTH ON THE EASTERLY WIND FLOW WILL PUSH THE TIDE
OVER. RIGHT NOW BELIEVE MINOR COASTAL FLOODING IS POSSIBLE ALONG THE
EAST COASTLINE.

WEDNESDAY EVENING...THE WIND GOES IN A MORE SOUTHERLY DIRECTION AND
THE TIDE WILL BE INCREASE ACROSS THE SOUTH COAST. HIGH TIDE IN
PROVIDENCE WILL BE 5.2 FT. 925 MB LLJ STRENGTHENS TO 50-60 KTS WHICH
COULD PUSH A DECENT SURGE UP ALONG THE SOUTH COAST DURING THE TIME
OF HIGH TIDE. THINKING THAT MINOR COASTAL FLOODING COULD OCCUR BUT
CANNOT RULE OUT MODERATE ALONG THE SOUTH COAST...ESP IF LLJ
STRENGTHENS EVEN MORE.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...FRANK/DUNTEN
NEAR TERM...FRANK
SHORT TERM...FRANK
LONG TERM...DUNTEN
AVIATION...FRANK/DUNTEN
MARINE...FRANK/DUNTEN
TIDES/COASTAL FLOODING...DUNTEN




000
FXUS61 KBOX 210916
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
416 AM EST SUN DEC 21 2014

.SYNOPSIS...
AN AREA OF SNOW SHOWERS WILL AFFECT AREAS MAINLY SOUTH OF THE MA
TURNPIKE THIS MORNING...EXCEPT IT WILL BE MILD ENOUGH FOR RAIN
SHOWERS ACROSS THE FAR SOUTHEAST NEW ENGLAND COAST. WEAK LOW
PRESSURE WILL PASS SOUTH OF NEW ENGLAND BRINGING ANOTHER PERIOD OF
PRECIPITATION MONDAY NIGHT AND TUESDAY. A MUCH STRONGER STORM
PASSING WEST OF NEW ENGLAND WILL BRING HEAVY RAINFALL...GUSTY
WINDS AND COASTAL FLOODING CONCERNS TO THE REGION WEDNESDAY AND
WEDNESDAY NIGHT. DRY BUT VERY WINDY CONDITIONS FOLLOW FOR
CHRISTMAS DAY.

&&

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

4 AM UPDATE...

APPROACHING SHORTWAVE HAS ALLOWED AN AREA LIGHT SNOW SHOWERS TO
EXPAND SOUTH OF THE MA TURNPIKE VERY EARLY THIS MORNING...BUT A FEW
SNOW SHOWERS DID EXTEND INTO NORTHERN MA.  RADAR IMAGERY ACTUALLY
OVER SHOOTING SOME OF THE ACTIVITY ACROSS NORTHERN CT...BASED ON
OBSERVATIONS.  THE RAIN/SNOW LINE RUNS ROUGHLY FROM NEWPORT...TO
TAUNTON AND JUST NORTH OF MARSHFIELD.  OVERALL...DO NOT EXPECT MUCH
CHANGE IN THE RAIN/SNOW LINE THIS MORNING BASED ON THERMAL PROFILES
AND POSITIONING OF THE COASTAL FRONT.

MAIN UNCERTAINTY IS JUST HOW MUCH SNOW OCCURS THIS MORNING WITH THE
SHORTWAVE MOVING ACROSS CT.  GIVEN THE TRACK OF THE SHORTWAVE...BEST
FORCING WILL BE LOCATED SOUTH OF THE MA TURNPIKE AND ESPECIALLY
ACROSS NORTHERN CT/RI.  WE WILL FORECAST 1 TO 2 INCHES OF SNOW
ACROSS THIS REGION...BUT A FEW ISOLATED 3 INCH AMOUNTS CAN NOT BE
RULED OUT. MEANWHILE...AREAS NORTH OF THE MA TURNPIKE WILL BE
REMOVED FROM THE BEST FORCING...BUT STILL SEE SOME SCATTERED
SHOWERS.  ACCUMS IN THIS AREA LIKELY TO BE A DUSTING TO LESS THAN AN
INCH.

ALSO...SOME OF THE PRECIPITATION CURRENTLY ACROSS SOUTHEAST MA IS
BEING ENHANCED FROM THE COASTAL FRONT.  A LOT OF THIS PRECIP WILL
BE IN THE FORM OF RAIN SHOWERS ACROSS PLYMOUTH AND EVEN INTO
PORTIONS OF BRISTOL COUNTY...POINTS SOUTH AND EAST.  HOWEVER...AT
LEAST THE SLIGHTLY HIGHER TERRAIN OF SOUTHEAST MA SHOULD SEE SNOW
SHOWERS.  WILL HAVE TO KEEP A CLOSE EYE ON IF COASTAL FRONT SHIFTS
SLIGHTLY THIS MORNING.  IT COULD MEAN THE DIFFERENCE BETWEEN AN AREA
GETTING MAINLY RAIN SHOWERS OR PERHAPS AN INCH OR SO OF SNOW.
OVERALL...DO NOT EXPECT THE COASTAL FRONT TO MOVE TOO MUCH THIS
MORNING...BUT JUST A FEW MILES CAN MAKE DIFFERENCE FOR A
PARTICULARLY NEIGHBORHOOD.

BULK OF PRECIPITATION WILL BE THIS MORNING WITH THE SHORTWAVE.
HOWEVER...ENOUGH LOW LEVEL MOISTURE/WEAK LIFT WILL REMAIN THIS
AFTERNOON FOR AT LEAST THIS RISK OF SCATTERED PRECIPITATION AND WILL
MAINTAIN SOME POPS.  HIGH TEMPS MAINLY IN THE 30S.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...

TONIGHT...

A RATHER CLOUDY AND RAW NIGHT ACROSS SOUTHERN NEW ENGLAND.  WHILE
THERE IS NOT A SIGNIFICANT SHORTWAVE TO TRIGGER A LOT OF
PRECIPITATION...PLENTY OF LOW LEVEL MOISTURE/WEAK SHALLOW LIFT
REMAINS.  THIS MAY BE ENOUGH TO RESULT IN A FEW RAIN/SNOW SHOWER
FROM TIME TO TIME.  PTYPE...WOULD BE MAINLY SNOW SHOWERS EXCEPT TO
THE SOUTHEAST OF A NEWPORT...TO TAUNTON...TO JUST NORTH OF
MARSHFIELD LINE.  AGAIN...MUCH OF THE NIGHT WILL PROBABLY END UP
DRY...BUT JUST THE RISK FOR A FEW RAIN/SNOW SHOWERS.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...

HIGHLIGHTS...

* WEAK SHORTWAVE ON MON NIGHT/TUESDAY COULD BRING WINTRY
  MIX/FREEZING RAIN TO THE INTERIOR
* ANOMALOUS SYSTEM ACROSS THE GREAT LAKES WILL BRING HEAVY
  RAIN...GUSTY WINDS AND COASTAL FLOODING CONCERNS AROUND CHRISTMAS
  EVE
* BLUSTERY BUT AIRMASS WILL BE DRYING OUT ON CHRISTMAS DAY

OVERVIEW...

THE MODELS AND ENSEMBLES OFFER A REASONABLY SIMILAR AND PREDICTABLE
LARGER SCALE MID TO UPPER LEVEL PATTERN EVOLUTION FOR MUCH OF THE
UPCOMING WEEK. THIS ACTIVE FLOW REGIME DEVELOPS SEVERAL MID-UPPER
LEVEL TROUGH AND ASSOCIATED/UNSETTLING LEAD SURFACE LOW/FRONTAL
SYSTEMS AND PCPN SWATHS PROGRESS STEADILY ACROSS THE LOWER 48. THE
FIRST AMPLIFIED/DEEP LEAD SYSTEM WORKS ACROSS THE ERN/NERN US INTO
ERN CANADA CHRISTMAS EVE INTO CHRISTMAS ALLOWING FOR A MOIST/WARMED
AIRMASS IN ADVANCE OF FRONTAL APPROACH WITH HEAVIEST LEAD QPF
POTENTIAL OVER NEW ENGLAND. BIGGEST QUESTION IS THE EVOLUTION OF THE
SECONDARY LOW PRESSURE SYSTEM. 00Z GUIDANCE HAS BACKED OFF ON THE
STRENGTH OF THE LOW AND IS HAVING ISSUES ON HOW TO HANDLE ITS
EVOLUTION. THE EC AND GFS HAVE SLOWED DOWN THE SYSTEM SLIGHTLY WITH
THE EC HAVING MORE OF A NEGATIVE TROUGH VS THE GFS. BELIEVE THE
UKMET IS A GOOD COMPROMISE AT IS WAS THE FIRST DETERMINISTIC
GUIDANCE ON TAMPERING DOWN THE FIRST MAIN LOW...WHILE THE CMC IS OUT
TO LUNCH. REGARDLESS THIS IS A VERY ANOMALOUS SYSTEM THAT IS ABOUT 4
STANDARD DEVIATIONS AWAY.

A SECONDARY SYSTEM DEEPENS ACROSS THE FOUR CORNERS ON FRIDAY AND
WITH THE STUBBORN TROUGH OVER THE CENTRAL U.S...IT WILL PUSH A
SYSTEM TOWARDS SOUTHERN NEW ENGLAND BY SUNDAY. THIS SYSTEM MAY
SUPPORT A MODEST SWATH OF OVERRUNNING SNOW OVER SOUTHERN NEW
ENGLAND.

DETAILS...

MONDAY INTO TUESDAY...MODERATE CONFIDENCE.

A WEAK WAVE OF LOW PRESSURE DEVELOPS ALONG THE SOUTHEAST COAST
MONDAY...AND WILL BE ON A DEVELOPING WARM FRONTAL BOUNDARY. THIS LOW
REMAINS WEAK AS THE WARM FRONT MOVES SLOWLY NORTH MONDAY NIGHT INTO
TUESDAY. APPEARS THAT THERE IS DECENT WARM ADVECTION AHEAD OF THIS
WAVE. SEVERAL HI-RES GUIDANCE MODELS SHOW THAT THERE IS THE
POTENTIAL FOR COLD AIR DAMMING ACROSS THE INTERIOR INTO TUESDAY.
BIGGEST QUESTION WILL BE IS THERE ENOUGH MOISTURE FOR PRECIP DURING
THIS TIME FRAME. DUE TO A STRENGTHENING LLJ PROVIDING A GOOD SOURCE OF
LIFT ANTICIPATE PRECIP TO DEVELOP AND OVERSPREAD ACROSS SOUTHERN NEW
ENGLAND. IF THIS PLAYS OUT WITH COLD AIR DAMMING AND WARM AIR
ADVECTION...THEN WE COULD SEE FREEZING RAIN/DRIZZLE ACROSS THE I-91
CORRIDOR LATE MONDAY INTO TUESDAY MORNING. DURING THE DAY ON
TUESDAY...GOOD AMOUNT OF WARM AIR WILL PUSH SURFACE TEMPS ABOVE
FREEZING BY THE LATE MORNING ALLOWING FOR ANY PRECIP TO BE MORE OF
THE LIQUID VARIETY AHEAD OF THE CHRISTMAS EVE STORM. HOWEVER
GUIDANCE IS ALWAYS TOO FAST IN SCOURING TEMPS OUT ESP ACROSS THE CT
VALLEY SO WE WILL NEED TO MONITOR THIS CLOSELY...ESP DUE TO LIGHT
WINDS AND THE HIGH IN EASTERN CANADA. A WINTER WX ADVISORY MAY BE
NEEDED FOR THE LIGHT ICING POTENTIAL.

WE COULD ALSO SEE SOME MINOR COASTAL FLOODING CONCERNS ON TUESDAY. SEE
BELOW FOR MORE DETAILS.

WEDNESDAY INTO THURSDAY...HIGH CONFIDENCE IN SYSTEM LOW CONFIDENCE
ON DETAILS.

ANOMALOUS SYSTEM WILL STRENGTHEN OVER THE GREAT LAKES TUESDAY INTO
WEDNESDAY. A SECONDARY SHORTWAVE WILL ROUND THE DEEP TROUGH AND
DEVELOP A SECONDARY LOW PRESSURE ALONG THE COLD FRONT. THIS
SECONDARY LOW WILL STRENGTHEN AND PASS WEST OF SOUTHERN NEW ENGLAND.
THIS SYSTEM WILL CONTINUE TO DEEPEN AS IT MOVES TOWARDS EASTERN
CANADA SWINGING A COLD FRONT ACROSS THE NORTHEAST.

STRONG SOUTHERLY JET OUT AHEAD OF THE FRONT WITH A GULF MOISTURE
CONNECTION WILL IMPACT SOUTHERN NEW ENGLAND ON CHRISTMAS EVE. THIS
STRONG JET WILL YIELD FOR PCPN IN THE LIQUID VARIETY.  PW ANOMALIES
ARE BETWEEN +4 TO +5 STANDARD DEVIATIONS ABOVE NORMAL WHICH IS QUITE
ANOMALOUS FOR THIS TIME OF YEAR. IN FACT CURRENT PWATS ARE PROGGED
ABOVE 1.6 INCHES WITH MODEL QPF OVER 2 INCHES...AT THE VERY LEAST
COULD SEE URBAN AND POOR DRAINAGE FLOODING. LATEST EC EVEN SHOWS
OVER 2.5 INCHES OF QPF...AND WITH THE TROPICAL CONNECTION AND STRONG
SOUTHERLY FLOW COULD SEE HIGHER AMOUNTS DUE TO TOPOGRAPHY
ENHANCEMENTS. RAINFALL RECORDS MAY FALL IF EVERYTHING FALLS INTO
PLACE.

AHEAD OF THE FRONT...SOUTHERN NEW ENGLAND WILL WARM SECTOR WED INTO
THUR MORNING ALLOWING FOR TEMPERATURES TO BE WELL ABOVE AVERAGE. IN
FACT WE MAY BE CLOSE AT BREAKING RECORD HIGH TEMPS IF TEMPS WARM TO
60F OR ABOVE ON CHRISTMAS EVE. SINCE WE WILL BE IN THE WARM
SECTOR...AND SHOWALTERS CLOSE TO ZERO...ISOLATED THUNDER IS STILL
POSSIBLE.

STRONG LOW LEVEL WINDS WILL ALSO BE A CONCERN ESPECIALLY WEDNESDAY
NIGHT. THE ECMWF SHOWS EAST-SOUTHEAST WINDS 30-40 KNOTS ON WEDNESDAY
INCREASING TO 60-75 KNOTS BY WEDNESDAY NIGHT. STRONG DOWNPOURS MAY
OVERCOME THE LOW LEVEL INVERSION AND BRING STRONG GUSTS OF AT LEAST
30-40 KNOTS ESPECIALLY ALONG THE SOUTH COAST. A WIND ADVISORY MAY BE
NEEDED IN SOME AREAS.

CHRISTMAS DAY...MODERATE CONFIDENCE.

AS THE COLD FRONT PASSES THROUGH EARLY CHRISTMAS DAY...THE WEST
WINDS WILL HELP DRY THE AIRMASS ALLOWING FOR PARTLY SUNNY SKIES.
STRONG CAA ON THURSDAY WILL ALLOW DESCENT MIXING. WINDS IN THE SFC-
850 MB LAYER WILL BE 30-40 KNOTS AND POSSIBLY A LITTLE
HIGHER...WHICH WOULD REQUIRE A WIND ADVISORY FOR MUCH OF THE AREA.

FRIDAY-SUNDAY...LOWER CONFIDENCE

WEAK HIGH PRESSURE BUILDS OVER THE AREA FRIDAY INTO SATURDAY. THE
NEXT SHORTWAVE APPROACHES LATE SATURDAY INTO SUNDAY AND SHOULD BRING
INCREASING CLOUDS FROM WEST TO EAST ALONG WITH A CHANCE OF RAIN OR
SNOW SHOWERS MAINLY IN THE AFTERNOON AND AT NIGHT.

&&

.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.  MAINLY MVFR CONDITIONS
SOUTH OF THE MA TURNPIKE WITH BORDERLINE VFR TO MARGINAL MVFR CIGS
NORTH OF THE PIKE THROUGH TONIGHT.  AN AREA OF SNOW SHOWERS WILL
EXPAND MAINLY ACROSS AREAS SOUTH OF THE PIKE THIS MORNING...BUT A
FEW SNOW SHOWERS WILL STILL AFFECT NORTHERN MA.  VSBYS/CIGS MAY
BRIEFLY DROP TO IFR LEVELS IN NORTHERN CT/RI/SE MA.  PTYPE WILL BE
RAIN SHOWERS ACROSS MOST OF PLYMOUTH COUNTY AND ONTO THE
CAPE/ISLANDS WITH SNOW SHOWERS NORTH AND WEST.  BULK OF PRECIP THIS
MORNING...BUT A FEW LINGERING RAIN/SNOW SHOWERS STILL POSSIBLE THIS
AFTERNOON AND EVENING.

KBOS TERMINAL...MODERATE CONFIDENCE.  A FEW SNOW SHOWERS POSSIBLE
THIS MORNING BUT BULK OF ACTIVITY SHOULD BE SOUTH OF THE TERMINAL.

KBDL TERMINAL...MODERATE CONFIDENCE.  PERIOD OF SNOW SHOWERS THIS
MORNING MAY DROP AN INCH OR TWO OF SNOW.  MVFR CONDITIONS DOMINATE
TODAY....BUT A BRIEF PERIOD OF IFR CONDITIONS ARE POSSIBLE THIS
MORNING IN SNOW SHOWERS.

OUTLOOK...MONDAY THROUGH THURSDAY...MODERATE CONFIDENCE.

MONDAY...MVFR CIGS CONTINUE IN RI/EASTERN MASS IN MARINE EAST FLOW.
VFR IN THE WEST.

TUESDAY...VFR WITH SCATTERED MVFR IN ANY RAIN/SNOW SHOWERS.

WEDNESDAY...CONDITIONS LOWERING TO IFR IN RAIN/HEAVY RAIN. ISOLATED
THUNDERSTORMS POSSIBLE ESPECIALLY WEDNESDAY NIGHT. EAST-SOUTHEAST
SURFACE WINDS MAY GUST TO 35-45 KNOTS. WINDS AT 2000 FEET AGL WILL
REACH 50-60 KNOTS WEDNESDAY AFTERNOON AND EARLY NIGHT CREATING LOW
LEVEL WIND SHEAR CONCERNS.

CHRISTMAS DAY...WEST WIND GUSTING 30-40 KNOTS. CONDITIONS IMPROVING
TO VFR AS THE WIND BRINGS IN COOLER DRIER AIR.

&&

.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.

HIGH PRESSURE ACROSS QUEBEC WILL RESULT IN NORTHEAST WINDS ACROSS
THE WATERS THAT WILL GUST TO BETWEEN 15 AND 20 KNOTS.  THIS WILL
RESULT IN 2 TO 4 FOOT SEAS.  HOWEVER...NO HEADLINES PLANNED AS
CONDITIONS SHOULD REMAIN BELOW SMALL CRAFT ADVISORY THRESHOLDS.

OUTLOOK...MONDAY THROUGH THURSDAY...MODERATE CONFIDENCE

MONDAY...EAST TO NORTHEAST WINDS GUSTING AROUND 15 KNOTS OR LESS.
SEAS WILL HOLD AROUND 3-4 FEET...MAY INCREASE TO 5FT IN NORTHEAST
FLOW AS GUIDANCE MAY BE UNDERDONE.

TUESDAY... INCREASING EAST WINDS WITH FREQUENT GUSTS 25 TO 30 KNOTS.
SEAS WILL BUILD TO 5-6 FEET ON THE EXPOSED WATERS.  A SMALL CRAFT
ADVISORY MAY BE NEEDED.

WEDNESDAY...RAIN WILL BE HEAVY AT TIMES PRODUCING POOR VISIBILITY.
INCREASING SOUTHEAST WINDS 20-25 SUSTAINED AND 40 KNOT GUSTS.  WINDS
SHOULD SHIFT TO SOUTH WEDNESDAY NIGHT AND SOUTHWEST TOWARD THURSDAY
MORNING. RAIN WILL TAPER OFF WITH THE WIND SHIFT TO SOUTHWEST. SEAS
WILL CONTINUE TO BUILD WITH 7-11 FEET HEIGHTS ON THE EXPOSED WATERS.
A GALE WARNING WILL BE NEEDED...WITH A LOW PROB OF A FEW STORM FORCE
GUSTS ACROSS THE EASTERN OUTER WATERS.

CHRISTMAS DAY... WEST SOUTHWEST WINDS WILL CONTINUE TO GUST 35-40
KNOTS...SO A CONTINUED GALE WARNING MAY BE NEEDED. SEAS OF 7-15 FEET
ARE POSSIBLE ON THE EXPOSED WATERS...AND 5 FEET IS POSSIBLE ON SOME
OF THE NEARSHORE WATERS.

&&

.TIDES/COASTAL FLOODING...

HIGH ASTRONOMICAL TIDES WILL OCCUR TUESDAY THROUGH THURSDAY. BREAKING
IT DOWN...ON TUESDAY HIGH TIDE AT BOSTON WILL BE 11.6 FT. THERE WILL
BE ONSHORE FLOW DURING THIS HIGH TIDE ALLOWING FOR MINOR SPLASHOVER.
IF WIND GUSTS INCREASE THEN COULD POSSIBLE SEE MINOR COASTAL
FLOODING.

ON WEDNESDAY...WINDS WILL SWITCH TO A MORE SOUTHEASTERLY FLOW DURING
THE DAY AND INCREASE QUICKLY FROM APPROACHING SYSTEM AND DECENT
PRESSURE FALLS. WEDNESDAY AFTERNOON HIGH TIDE IN BOSTON IS 11.7 FT
AND WITH ANY STRENGTH ON THE EASTERLY WIND FLOW WILL PUSH THE TIDE
OVER. RIGHT NOW BELIEVE MINOR COASTAL FLOODING IS POSSIBLE ALONG THE
EAST COASTLINE.

WEDNESDAY EVENING...THE WIND GOES IN A MORE SOUTHERLY DIRECTION AND
THE TIDE WILL BE INCREASE ACROSS THE SOUTH COAST. HIGH TIDE IN
PROVIDENCE WILL BE 5.2 FT. 925 MB LLJ STRENGTHENS TO 50-60 KTS WHICH
COULD PUSH A DECENT SURGE UP ALONG THE SOUTH COAST DURING THE TIME
OF HIGH TIDE. THINKING THAT MINOR COASTAL FLOODING COULD OCCUR BUT
CANNOT RULE OUT MODERATE ALONG THE SOUTH COAST...ESP IF LLJ
STRENGTHENS EVEN MORE.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...FRANK/DUNTEN
NEAR TERM...FRANK
SHORT TERM...FRANK
LONG TERM...DUNTEN
AVIATION...FRANK/DUNTEN
MARINE...FRANK/DUNTEN
TIDES/COASTAL FLOODING...DUNTEN





000
FXUS61 KBOX 210626
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
123 AM EST SUN DEC 21 2014

.SYNOPSIS...

SCATTERED SNOW/RAIN SHOWERS WILL AFFECT THE REGION THROUGH SUN.
WEAK LOW PRESSURE WILL PASS SOUTH OF NEW ENGLAND BRINGING ANOTHER
PERIOD OF PRECIPITATION MONDAY NIGHT AND TUESDAY. A MUCH STRONGER
STORM PASSING WEST OF NEW ENGLAND WILL BRING HEAVY
RAINFALL...GUSTY WINDS AND COASTAL FLOODING CONCERNS TO THE REGION
WEDNESDAY AND WEDNESDAY NIGHT. DRY BUT VERY WINDY CONDITIONS
FOLLOW FOR CHRISTMAS DAY.

&&

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

120 AM UPDATE...

LIGHT SNOW SHOWERS CONTINUE TO FALL ACROSS INTERIOR SOUTHEAST MA AND
INTO RI VERY EARLY THIS MORNING.  COASTAL FRONT RUNS ROUGHLY FROM
NEAR NEW BEDFORD...TO TAUNTON AND NORTH OF MARSHFIELD THIS MORNING.
PTYPE MAINLY SNOW NORTHWEST OF THIS LINE AND RAIN SOUTHEAST OF THIS
LOCATION.

MEANWHILE...ACROSS THE REST OF THE REGION IT WAS DRY EARLY THIS
MORNING OTHER THAN A FLURRIES.  HOWEVER...APPROACHING SHORTWAVE WILL
MOVE ACROSS CT LATER THIS MORNING.  THIS WILL RESULT IN ENOUGH
FORCING FOR SCATTERED SNOW SHOWERS TO OVERSPREAD NORTHERN CT AND
INTO MUCH OF SOUTHERN MA.  SNOW ACCUMULATIONS THIS MORNING SHOULD
RANGE FROM A COATING TO 2 INCHES ACROSS THE REGION.  WE DID ISSUE A
SPECIAL WEATHER STATEMENT TO HIGHLIGHT THE CONCERN FOR SLIPPERY
TRAVEL.  BULK OF THE ACTION WILL BE SOUTH OF THE PIKE...WHERE BETTER
FORCING RESIDES.  HOWEVER...STILL COULD SEE A FEW SNOW SHOWERS WITH
ACCUMS GENERALLY A DUSTING TO LESS THAN AN INCH ACROSS NORTHERN MA.

PTYPE SHOULD REMAIN WARM ENOUGH FOR RAIN SHOWERS ACROSS MUCH OF
PLYMOUTH COUNTY AND ONTO THE CAPE/ISLANDS THIS MORNING...WITH MAINLY
SNOW SHOWERS NORTH AND WEST.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM MONDAY/...
RAIN/SNOW SHOWERS WILL CONTINUE INTO THE MORNING HOURS...THEN TAPER
OFF AS INVERTED TROUGH PULLS AWAY FROM SOUTHERN NEW ENGLAND AND HIGH
PRESSURE STARTS TO BUILD IN.  MOST LIKELY AREAS FOR CONTINUING
SHOWERS WILL BE ALONG THE IMMEDIATE EAST COAST OF MASSACHUSETTS.

AS THE DAY GOES ON...EXPECT A SLOW DRYING TREND AS HIGH PRESSURE
BUILDS INTO THE REGION.  CLOUDS WILL STICK AROUND WITH TEMPS
GENERALLY IN THE 30S.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
BIG PICTURE... SHORTWAVE ENTERING THE PACIFIC NORTHWEST CROSSES THE
ROCKIES OVER THE WEEKEND DRIVEN BY A 160-KNOT JET.  THIS DIGS A
SUBSTANTIAL TROUGH OVER THE PLAINS MONDAY-TUESDAY WHILE PACIFIC HIGH
PRESSURE BUILDS ALONG THE PACIFIC COAST. THIS IN TURN WILL ALLOW AN
UPPER RIDGE TO BUILD ALONG THE ATLANTIC COAST AND SLOWLY SHIFT EAST
OF THE COAST.  THE JET ENERGY WORKS ITS WAY AROUND THE BASE OF THE
PLAINS TROUGH AND MOVES UP THE APPALACHANS MIDWEEK.  THIS SUPPORTS A
TRANSITION OF THE TROUGH TO NEGATIVE TILT AND SLOWER MOVEMENT...WITH
WARM MOIST AIR FOR THE ATLANTIC COAST. THE TROUGH AXIS SWINGS OVER
NEW ENGLAND CHRISTMAS DAY FOLLOWED BY A WEAK RIDGE. ANOTHER
SHORTWAVE MOVES ASHORE FROM THE PACIFIC MIDWEEK AND MOVES ACROSS THE
PLAINS BY THE END OF THE WEEK AND APPROACHES THE NORTHEAST USA
SATURDAY.

THERE IS SOME SPREAD IN DETAILS AMONG THE LONG RANGE MODELS...BUT
ALL SHOW A SIMILAR SCENARIO BOTH FOR THE MIDWEEK SYSTEM AND THE END
OF WEEK SYSTEM.  WE USED A BLEND OF GFS/ECMWF.

THE DAILIES...

SUNDAY NIGHT-MONDAY... HIGH PRESSURE REMAINS NORTH OF THE REGION
BRINGING A MOIST EAST FLOW ACROSS SOUTHERN NEW ENGLAND. UPPER
PATTERN SHOWS WEAK RIDGING AS THE PLAINS TROUGH DIGS...BUT SURFACE
FIELDS SUGGEST A LINGERING INVERTED TROUGH ALONG OR JUST OFFSHORE.
THIS SHOULD MAINTAIN CONSIDERABLE CLOUDS. COULD BE SOME DRIZZLE OR
FLURRIES NEAR THE EAST COAST BUT SUPPORTING LARGE SCALE ASCENT IS
LACKING SO PCPN SHOULD BE LIMITED.

MONDAY NIGHT-TUESDAY... LOW PRESSURE FORMS ALONG A STALLED WARM
FRONT OFF THE MID ATLANTIC COAST. AS THE LOW DEVELOPS...IT BRINGS
AN INCREASED PRESSURE GRADIENT AGAINST HIGH PRESSURE MOVING
THROUGH THE MARITIMES. THE RESULT WILL BE A STRENGTHENING LOW
LEVEL EAST- SOUTHEAST JET. THIS WILL INCREASE THE MOIST INFLOW
OVER SOUTHERN NEW ENGLAND. ALSO...AS THE JET CONVERGES ON THE
INVERTED SURFACE TROUGH IT WILL GENERATE INCREASED LOW LEVEL LIFT
AND INCREASE THE CHANCE OF PCPN. WE WILL HAVE CLOUDS AND CHANCE
POPS. TEMPS IN NORTHWEST MASS WILL BE COLD ENOUGH SO THAT THERE
MAY BE A MIX OF PCPN TYPES DURING THE MORNING.

TUESDAY NIGHT-WEDNESDAY... PLAINS UPPER TROUGH DIGS DEEPER AND MOVES
EAST...PUSHING THE UPPER RIDGE TO OUR EAST. ALSO...THE STRONG UPPER
SOUTHWEST JET MOVES UP OVER THE EASTERN USA. THIS SETUP WILL TAKE
THE PRIMARY SURFACE LOW UP THROUGH THE WESTERN GREAT LAKES.
SECONDARY LOWS FORMING ON THE SYSTEM COLD FRONT WILL MOVE OUT OF THE
GULF OF MEXICO TOWARD THE GREAT LAKES. A SOUTHWEST LOW LEVEL JET
WILL MOVE UP THE ATLANTIC COAST ON WEDNESDAY AND OVER THE TOP OF THE
EAST-SOUTHEAST FLOW AT THE SURFACE. THE RESULT WILL BE PLENTY OF LOW
LEVEL LIFT THE GENERATE PCPN.

PRECIPITABLE WATER VALUES ARE FORECAST TO EXCEED 1.5 INCHES...WHICH
IS 3 STD DEVIATIONS ABOVE NORMAL FOR DECEMBER.  THIS MEANS A LOT OF
WATER AVAILABLE AS PCPN. TEMPERATURE PROFILES WILL BE ABOVE FREEZING
SO PTYPE SHOULD BE RAIN. MODEL QPF SHOWS POTENTIAL RAINFALL OF OVER
2 INCHES. THIS WOULD SUGGEST POTENTIAL URBAN/POOR DRAINAGE FLOODING
ISSUES WEDNESDAY.

STRONG LOW LEVEL WINDS WILL ALSO BE A CONCERN ESPECIALLY WEDNESDAY
NIGHT. THE ECMWF SHOWS EAST-SOUTHEAST WINDS 30-35 KNOTS ALONG HE
EAST MASS COAST AT 1000 MB. THEN WEDNESDAY NIGHT WINDS AT 925 MB
INCREASE TO 60-75 KNOTS AND MOVE ACROSS COASTAL RI AND SOUTHEAST
MASS. STRONG DOWNPOURS MAY OVERCOME THE LOW LEVEL INVERSION AND
BRING STRONG GUSTS OF AT LEAST 30-40 KNOTS ESPECIALLY ALONG THE
SOUTH COAST. A WIND ADVISORY MAY BE NEEDED IN SOME AREAS.

MAINTAINED A LIMITED MENTION OF THUNDER...AS CONVECTIVE PARAMETERS
ARE MARGINAL...SI VALUES WILL BE JUST ABOVE ZERO AND K INDEX WILL BE
IN THE LOW 30S WEDNESDAY NIGHT.

UPPER LOW WILL SWING THE SURFACE COLD FRONT THROUGH SOUTHERN NEW
ENGLAND WEDNESDAY NIGHT. WINDS WILL THEN SHIFT TO WEST AND PCPN
SHOULD COME TO AN END AROUND THE TIME THAT SANTA ARRIVES.

CHRISTMAS DAY... WEST WINDS WILL BRING A DRYING OF THE AIRMASS
DURING THE DAY. SO THE TREND SHOULD BE TO AT LEAST PARTIAL CLEARING.
SUFFICIENT COLD ADVECTION AT ALL LEVELS THURSDAY WILL ALLOW SOME
MIXING.  WINDS IN THE SFC-850 MB LAYER WILL BE 30-40 KNOTS AND
POSSIBLY A LITTLE HIGHER...WHICH WOULD REQUIRE A WIND ADVISORY FOR
MUCH OF THE AREA.

FRIDAY-SATURDAY... WEAK HIGH PRESSURE BUILDS OVER THE AREA FRIDAY
AND BRING A SUNNY DAY. THE NEXT PACIFIC SHORTWAVE APPROACHES
SATURDAY AND SHOULD BRING INCREASING CLOUDS FROM WEST TO EAST ALONG
WITH A CHANCE OF RAIN OR SNOW SHOWERS MAINLY IN THE AFTERNOON AND AT
NIGHT.

&&

.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.  MAINLY MVFR CONDITIONS
SOUTH OF THE MA TURNPIKE WITH BORDERLINE VFR TO MARGINAL MVFR CIGS
NORTH OF THE PIKE THROUGH TONIGHT.  AN AREA OF SNOW SHOWERS WILL
EXPAND MAINLY ACROSS AREAS SOUTH OF THE PIKE THIS MORNING...BUT A
FEW SNOW SHOWERS ARE POSSIBLE IN THE NORTHERN MA.  VSBYS MAY BRIEFLY
DROP TO IFR LEVELS IN NORTHERN CT/RI/SE MA.  PTYPE WILL BE RAIN
SHOWERS ACROSS MOST OF PLYMOUTH COUNTY AND ONTO THE CAPE/ISLANDS WITH
SNOW SHOWERS NORTH AND WEST.  BULK OF PRECIP THIS MORNING...BUT A
FEW LINGERING RAIN/SNOW SHOWERS STILL POSSIBLE THIS AFTERNOON AND
EVENING.

KBOS TERMINAL...MODERATE CONFIDENCE.  A FEW SNOW SHOWERS POSSIBLE
BUT BULK OF ACTIVITY SHOULD BE SOUTH OF THE TERMINAL.

KBDL TERMINAL...MODERATE CONFIDENCE.  PERIOD OF SNOW SHOWERS THIS
MORNING MAY DROP A COATING TO PERHAPS UP TO AN INCH OR TWO OF SNOW.
MVFR CONDITIONS DOMINATE TODAY....BUT A BRIEF PERIOD OF IFR
CONDITIONS ARE POSSIBLE THIS MORNING.

OUTLOOK...MONDAY THROUGH THURSDAY...MODERATE CONFIDENCE

MONDAY...MVFR CIGS CONTINUE IN RI/EASTERN MASS IN MARINE EAST FLOW.
VFR IN THE WEST.

TUESDAY...VFR WITH SCATTERED MVFR IN ANY RAIN/SNOW SHOWERS.

WEDNESDAY...CONDITIONS LOWERING TO IFR IN RAIN/HEAVY RAIN. ISOLATED
THUNDERSTORMS POSSIBLE ESPECIALLY WEDNESDAY NIGHT. EAST-SOUTHEAST
SURFACE WINDS MAY GUST TO 35 KNOTS ALONG THE EAST MASSACHUSETTS
COAST. WINDS AT 2000 FEET AGL WILL REACH 50-60 KNOTS WEDNESDAY
AFTERNOON AND EARLY NIGHT CREATING LOW LEVEL WIND SHEAR CONCERNS.

CHRISTMAS DAY...WEST WIND GUSTING 30-40 KNOTS. CONDITIONS IMPROVING
TO VFR AS THE WIND BRINGS IN COOLER DRIER AIR.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

HIGH CONFIDENCE. HIGH PRESSURE ACROSS QUEBEC WILL RESULT IN
PERSISTENT NORTHEAST WINDS ACROSS THE WATERS THROUGH THE WEEKEND.
WIND GUSTS UP TO 20 KNOTS WITH SEAS BETWEEN 2 AND 4 FEET ARE
EXPECTED FOR MOST WATERS...SO NO HEADLINES PLANNED.

THERE IS A LOW PROBABILITY THAT A BRIEF SURGE OF NORTHEAST WIND
GUSTS NEAR 25 KNOTS WITH MARGINAL 5 FOOT SEAS COULD AFFECT OUR
NORTHERN WATERS LATE TONIGHT INTO SUN MORNING...BUT NOT CONFIDENT
ENOUGH TO ISSUE ANY HEADLINES AT THIS POINT.

OUTLOOK...SUNDAY NIGHT THROUGH THURSDAY...MODERATE CONFIDENCE

SUNDAY NIGHT-MONDAY...EAST TO NORTHEAST WINDS GUSTING AROUND 15
KNOTS OR LESS.  SEAS WILL HOLD AROUND 3-4 FEET.

TUESDAY... INCREASING EAST WINDS WITH FREQUENT GUSTS 25 TO 30 KNOTS.
SEAS WILL BUILD TO 5-6 FEET ON THE EXPOSED WATERS.  A SMALL CRAFT
ADVISORY MAY BE NEEDED.

WEDNESDAY...RAIN WILL BE HEAVY AT TIMES PRODUCING POOR VISIBILITY.
INCREASING SOUTHEAST WINDS 20-25 SUSTAINED AND 40 KNOT GUSTS.  WINDS
SHOULD SHIFT TO SOUTH WEDNESDAY NIGHT AND SOUTHWEST TOWARD THURSDAY
MORNING. RAIN WILL TAPER OFF WITH THE WIND SHIFT TO SOUTHWEST. SEAS
WILL CONTINUE TO BUILD WITH 5-10 FEET HEIGHTS ON THE EXPOSED WATERS.
A GALE WARNING MAY BE NEEDED.

CHRISTMAS DAY... WEST SOUTHWEST WINDS WILL CONTINUE TO GUST 35-40
KNOTS...SO A GALE WARNING MAY CONTINUE TO BE NEEDED. SEAS OF 10-15
FEET ARE POSSIBLE ON THE EXPOSED WATERS...AND 5 FEET IS POSSIBLE ON
SOME OF THE NEARSHORE WATERS.

&&

.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES WILL OCCUR
TUESDAY THROUGH THURSDAY. BREAKING IT DOWN...ON TUESDAY HIGH TIDE
AT BOSTON WILL BE 11.6 FT. THERE WILL BE EAST WINDS DURING THIS
HIGH TIDE ALLOWING FOR MINOR SPLASHOVER ALONG THE MASS COAST. IF
WIND GUSTS INCREASE THEN COULD POSSIBLE SEE MINOR COASTAL
FLOODING.

ON WEDNESDAY...WINDS WILL SWITCH TO A MORE SOUTHEASTERLY FLOW DURING
THE DAY AND INCREASE QUICKLY DUE TO THE APPROACHING SYSTEM.
WEDNESDAY AFTERNOON HIGH TIDE IN BOSTON IS 11.7 FT...AND AN
APPRECIABLE EAST OR SOUTHEAST WIND SHOULD PUSH LEVELS HIGHER THAN ON
TUESDAY.  THIS WOULD PROBABLY BE THE BEST CHANCE OF MINOR COASTAL
FLOODING ALONG THE EAST COAST.

THE WEDNESDAY EVENING HIGH TIDE WILL BE A LITTLE LOWER...BUT THE
WIND BECOMES SOUTH WITH 50-60 KNOTS AT 2000 FEET ABOVE THE SURFACE
AVAILABLE TO BE BROUGHT DOWN IN GUSTS. HIGH TIDE IN PROVIDENCE WILL
BE 5.2 FT. MINOR COASTAL FLOODING COULD OCCUR ALONG THE SOUTH
COASTS OF RI AND MASS...AND COULD BE CHANNELED IN NORTH-SOUTH AXIS
BAYS SUCH AS NARRAGANSETT BAY.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...WTB/RLG
NEAR TERM...FRANK
SHORT TERM...RLG
LONG TERM...WTB
AVIATION...FRANK/WTB
MARINE...WTB/RLG
TIDES/COASTAL FLOODING...STAFF




000
FXUS61 KBOX 210220
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
918 PM EST SAT DEC 20 2014

.SYNOPSIS...
SCATTERED SNOW/RAIN SHOWERS WILL AFFECT THE REGION THROUGH SUN.
WEAK LOW PRESSURE WILL PASS SOUTH OF NEW ENGLAND BRINGING ANOTHER
PERIOD OF PRECIPITATION MONDAY NIGHT AND TUESDAY. A MUCH STRONGER
STORM PASSING WEST OF NEW ENGLAND WILL BRING HEAVY
RAINFALL...GUSTY WINDS AND COASTAL FLOODING CONCERNS TO THE REGION
WEDNESDAY AND WEDNESDAY NIGHT. DRY BUT VERY WINDY CONDITIONS
FOLLOW FOR CHRISTMAS DAY.

&&

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

915 PM UPDATE...

A RATHER TRICKY FORECAST OVERNIGHT WITH INVERTED TROUGH/COASTAL
FRONT RESULTING IN SOME MESOSCALE PROCESSES.  MAIN BAND OF SNOW THAT
HAS DROPPED A NARROW BAND OF 1 TO 2 INCHES OF SNOW ACROSS PORTIONS
OF BOSTON/S SOUTH SHORE WAS GRADUALLY PRESSING SOUTHWEST THIS
EVENING.  THIS PARTLY IN RESPONSE TO A SUBTLE COASTAL FRONT THAT WAS
ALSO SHIFTING FURTHER WEST INTO PLYMOUTH AND EVEN FAR EASTERN
NORFOLK COUNTY.  MILDER AIR WAS ALSO CAUSING SOME OF THESE AREAS TO
MIX WITH OR CHANGE TO RAIN.

OVERALL...STILL THINK THAT A COATING TO AT MOST 2 INCHES WILL COVER
IT FOR MOST OF SOUTHERN NEW ENGLAND INTO SUNDAY.  WE DID OPT TO
SHIFT THE BEST RISK FOR THE 1 TO 2 INCHES A BIT FURTHER SOUTH AND
WEST BASED ON RADAR RETURNS AND LATEST GUIDANCE.  LOW RISK OF
ISOLATED 3 INCH AMOUNTS REMAINS POSSIBLE.

THE RAIN/SNOW LINE WILL LIKELY HANG OUT ACROSS FAR EASTERN
NORFOLK/PLYMOUTH AND PERHAPS FAR SOUTHEAST BRISTOL COUNTIES.  THE
MODELS MAY BE SLIGHTLY UNDER ESTIMATING THE WESTWARD PUSH OF THIS
LINE...SO SOMETHING TO WATCH BUT DO NOT THINK IT WILL GET MUCH
FURTHER WEST THAN THAT.

FINALLY...SCATTERED SNOW SHOWERS MAY ALSO DEVELOP INTO WESTERN
MA/NORTHERN CONNECTICUT OVERNIGHT INTO SUNDAY MORNING WITH A
APPROACHING SHORTWAVE.  MODEL GUIDANCE DIFFERS ON EXACTLY HOW THIS
WILL UNFOLD...BUT INCREASING EAST TO SOUTHEAST FLOW JUST OFF THE
GROUND SHOULD ALLOW FOR AT LEAST SOME ACTIVITY IN OUR WESTERN ZONES
BY DAYBREAK.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
RAIN/SNOW SHOWERS WILL CONTINUE INTO THE MORNING HOURS...THEN TAPER
OFF AS INVERTED TROUGH PULLS AWAY FROM SOUTHERN NEW ENGLAND AND HIGH
PRESSURE STARTS TO BUILD IN.  MOST LIKELY AREAS FOR CONTINUING
SHOWERS WILL BE ALONG THE IMMEDIATE EAST COAST OF MASSACHUSETTS.

AS THE DAY GOES ON...EXPECT A SLOW DRYING TREND AS HIGH PRESSURE
BUILDS INTO THE REGION.  CLOUDS WILL STICK AROUND WITH TEMPS
GENERALLY IN THE 30S.

&&

.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
BIG PICTURE... SHORTWAVE ENTERING THE PACIFIC NORTHWEST CROSSES THE
ROCKIES OVER THE WEEKEND DRIVEN BY A 160-KNOT JET.  THIS DIGS A
SUBSTANTIAL TROUGH OVER THE PLAINS MONDAY-TUESDAY WHILE PACIFIC HIGH
PRESSURE BUILDS ALONG THE PACIFIC COAST. THIS IN TURN WILL ALLOW AN
UPPER RIDGE TO BUILD ALONG THE ATLANTIC COAST AND SLOWLY SHIFT EAST
OF THE COAST.  THE JET ENERGY WORKS ITS WAY AROUND THE BASE OF THE
PLAINS TROUGH AND MOVES UP THE APPALACHANS MIDWEEK.  THIS SUPPORTS A
TRANSITION OF THE TROUGH TO NEGATIVE TILT AND SLOWER MOVEMENT...WITH
WARM MOIST AIR FOR THE ATLANTIC COAST. THE TROUGH AXIS SWINGS OVER
NEW ENGLAND CHRISTMAS DAY FOLLOWED BY A WEAK RIDGE. ANOTHER
SHORTWAVE MOVES ASHORE FROM THE PACIFIC MIDWEEK AND MOVES ACROSS THE
PLAINS BY THE END OF THE WEEK AND APPROACHES THE NORTHEAST USA
SATURDAY.

THERE IS SOME SPREAD IN DETAILS AMONG THE LONG RANGE MODELS...BUT
ALL SHOW A SIMILAR SCENARIO BOTH FOR THE MIDWEEK SYSTEM AND THE END
OF WEEK SYSTEM.  WE USED A BLEND OF GFS/ECMWF.

THE DAILIES...

SUNDAY NIGHT-MONDAY... HIGH PRESSURE REMAINS NORTH OF THE REGION
BRINGING A MOIST EAST FLOW ACROSS SOUTHERN NEW ENGLAND. UPPER
PATTERN SHOWS WEAK RIDGING AS THE PLAINS TROUGH DIGS...BUT SURFACE
FIELDS SUGGEST A LINGERING INVERTED TROUGH ALONG OR JUST OFFSHORE.
THIS SHOULD MAINTAIN CONSIDERABLE CLOUDS. COULD BE SOME DRIZZLE OR
FLURRIES NEAR THE EAST COAST BUT SUPPORTING LARGE SCALE ASCENT IS
LACKING SO PCPN SHOULD BE LIMITED.

MONDAY NIGHT-TUESDAY... LOW PRESSURE FORMS ALONG A STALLED WARM
FRONT OFF THE MID ATLANTIC COAST. AS THE LOW DEVELOPS...IT BRINGS
AN INCREASED PRESSURE GRADIENT AGAINST HIGH PRESSURE MOVING
THROUGH THE MARITIMES. THE RESULT WILL BE A STRENGTHENING LOW
LEVEL EAST- SOUTHEAST JET. THIS WILL INCREASE THE MOIST INFLOW
OVER SOUTHERN NEW ENGLAND. ALSO...AS THE JET CONVERGES ON THE
INVERTED SURFACE TROUGH IT WILL GENERATE INCREASED LOW LEVEL LIFT
AND INCREASE THE CHANCE OF PCPN. WE WILL HAVE CLOUDS AND CHANCE
POPS. TEMPS IN NORTHWEST MASS WILL BE COLD ENOUGH SO THAT THERE
MAY BE A MIX OF PCPN TYPES DURING THE MORNING.

TUESDAY NIGHT-WEDNESDAY... PLAINS UPPER TROUGH DIGS DEEPER AND MOVES
EAST...PUSHING THE UPPER RIDGE TO OUR EAST. ALSO...THE STRONG UPPER
SOUTHWEST JET MOVES UP OVER THE EASTERN USA. THIS SETUP WILL TAKE
THE PRIMARY SURFACE LOW UP THROUGH THE WESTERN GREAT LAKES.
SECONDARY LOWS FORMING ON THE SYSTEM COLD FRONT WILL MOVE OUT OF THE
GULF OF MEXICO TOWARD THE GREAT LAKES. A SOUTHWEST LOW LEVEL JET
WILL MOVE UP THE ATLANTIC COAST ON WEDNESDAY AND OVER THE TOP OF THE
EAST-SOUTHEAST FLOW AT THE SURFACE. THE RESULT WILL BE PLENTY OF LOW
LEVEL LIFT THE GENERATE PCPN.

PRECIPITABLE WATER VALUES ARE FORECAST TO EXCEED 1.5 INCHES...WHICH
IS 3 STD DEVIATIONS ABOVE NORMAL FOR DECEMBER.  THIS MEANS A LOT OF
WATER AVAILABLE AS PCPN. TEMPERATURE PROFILES WILL BE ABOVE FREEZING
SO PTYPE SHOULD BE RAIN. MODEL QPF SHOWS POTENTIAL RAINFALL OF OVER
2 INCHES. THIS WOULD SUGGEST POTENTIAL URBAN/POOR DRAINAGE FLOODING
ISSUES WEDNESDAY.

STRONG LOW LEVEL WINDS WILL ALSO BE A CONCERN ESPECIALLY WEDNESDAY
NIGHT. THE ECMWF SHOWS EAST-SOUTHEAST WINDS 30-35 KNOTS ALONG HE
EAST MASS COAST AT 1000 MB. THEN WEDNESDAY NIGHT WINDS AT 925 MB
INCREASE TO 60-75 KNOTS AND MOVE ACROSS COASTAL RI AND SOUTHEAST
MASS. STRONG DOWNPOURS MAY OVERCOME THE LOW LEVEL INVERSION AND
BRING STRONG GUSTS OF AT LEAST 30-40 KNOTS ESPECIALLY ALONG THE
SOUTH COAST. A WIND ADVISORY MAY BE NEEDED IN SOME AREAS.

MAINTAINED A LIMITED MENTION OF THUNDER...AS CONVECTIVE PARAMETERS
ARE MARGINAL...SI VALUES WILL BE JUST ABOVE ZERO AND K INDEX WILL BE
IN THE LOW 30S WEDNESDAY NIGHT.

UPPER LOW WILL SWING THE SURFACE COLD FRONT THROUGH SOUTHERN NEW
ENGLAND WEDNESDAY NIGHT. WINDS WILL THEN SHIFT TO WEST AND PCPN
SHOULD COME TO AN END AROUND THE TIME THAT SANTA ARRIVES.

CHRISTMAS DAY... WEST WINDS WILL BRING A DRYING OF THE AIRMASS
DURING THE DAY. SO THE TREND SHOULD BE TO AT LEAST PARTIAL CLEARING.
SUFFICIENT COLD ADVECTION AT ALL LEVELS THURSDAY WILL ALLOW SOME
MIXING.  WINDS IN THE SFC-850 MB LAYER WILL BE 30-40 KNOTS AND
POSSIBLY A LITTLE HIGHER...WHICH WOULD REQUIRE A WIND ADVISORY FOR
MUCH OF THE AREA.

FRIDAY-SATURDAY... WEAK HIGH PRESSURE BUILDS OVER THE AREA FRIDAY
AND BRING A SUNNY DAY. THE NEXT PACIFIC SHORTWAVE APPROACHES
SATURDAY AND SHOULD BRING INCREASING CLOUDS FROM WEST TO EAST ALONG
WITH A CHANCE OF RAIN OR SNOW SHOWERS MAINLY IN THE AFTERNOON AND AT
NIGHT.

&&

.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 SUNDAY/...

TONIGHT AND SUNDAY...MVFR CIGS/VSBYS IN RAIN/SNOW SHOWERS MOVING
WEST OFF THE OCEAN INTO SOUTHEASTERN MASS. THESE WILL SPREAD
FARTHER WEST INTO RI/CENTRAL MASS/NORTHEAST CT. LOCAL IFR
CIGS/VSBYS POSSIBLE WITH THE STRONGEST SHOWERS.

WINDS ARE ENE ALONG THE IMMEDIATE SOUTHEAST MASS COAST WITH NORTH
TO NORTHWEST WINDS ELSEWHERE. THIS WINDSHIFT MAY NUDGE FARTHER
WEST WITH THE SHOWERS EARLY TONIGHT.

MVFR CIGS MAY REACH THE CT VALLEY LATE TONIGHT BUT LOW CONFIDENCE
ABOUT ANY SIGNIFICANT REDUCTION IN VSBY THERE.

MVFR CIGS WILL LINGER MOST AREA ON SUNDAY. ANY CIGS THAT RISE
ABOVE MVFR SHOULD ONLY REACH AROUND 4000 FEET.

KBOS TERMINAL...MODERATE CONFIDENCE IN TAF. FLURRIES AND SNOW
SHOWERS THROUGH 06Z WITH POTENTIAL FOR WINDSHIFT TO 040 DURING
THIS TIME.

KBDL TERMINAL...MODERATE CONFIDENCE IN TAF.

OUTLOOK...SUNDAY NIGHT THROUGH THURSDAY...MODERATE CONFIDENCE

SUNDAY NIGHT-MONDAY...MVFR CIGS CONTINUE IN RI/EASTERN MASS IN
MARINE EAST FLOW. VFR IN THE WEST.

TUESDAY...VFR WITH SCATTERED MVFR IN ANY RAIN/SNOW SHOWERS.

WEDNESDAY...CONDITIONS LOWERING TO IFR IN RAIN/HEAVY RAIN. ISOLATED
THUNDERSTORMS POSSIBLE ESPECIALLY WEDNESDAY NIGHT. EAST-SOUTHEST
SURFACE WINDS MAY GUST TO 35 KNOTS ALONG THE EAST MASSACHUSETTS
COAST. WINDS AT 2000 FEET AGL WILL REACH 50-60 KNOTS WEDNESDAY
AFTERNOON AND EARLY NIGHT CREATING LOW LEVEL WIND SHEAR CONCERNS.

CHRISTMAS DAY...WEST WIND GUSTING 30-40 KNOTS. CONDITIONS IMPROVING
TO VFR AS THE WIND BRINGS IN COOLER DRIER AIR.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

HIGH CONFIDENCE. HIGH PRESSURE ACROSS QUEBEC WILL RESULT IN
PERSISTENT NORTHEAST WINDS ACROSS THE WATERS THROUGH THE WEEKEND.
WIND GUSTS UP TO 20 KNOTS WITH SEAS BETWEEN 2 AND 4 FEET ARE
EXPECTED FOR MOST WATERS...SO NO HEADLINES PLANNED.

THERE IS A LOW PROBABILITY THAT A BRIEF SURGE OF NORTHEAST WIND
GUSTS NEAR 25 KNOTS WITH MARGINAL 5 FOOT SEAS COULD AFFECT OUR
NORTHERN WATERS LATE TONIGHT INTO SUN MORNING...BUT NOT CONFIDENT
ENOUGH TO ISSUE ANY HEADLINES AT THIS POINT.

OUTLOOK...SUNDAY NIGHT THROUGH THURSDAY...MODERATE CONFIDENCE

SUNDAY NIGHT-MONDAY...EAST TO NORTHEAST WINDS GUSTING AROUND 15
KNOTS OR LESS.  SEAS WILL HOLD AROUND 3-4 FEET.

TUESDAY... INCREASING EAST WINDS WITH FREQUENT GUSTS 25 TO 30 KNOTS.
SEAS WILL BUILD TO 5-6 FEET ON THE EXPOSED WATERS.  A SMALL CRAFT
ADVISORY MAY BE NEEDED.

WEDNESDAY...RAIN WILL BE HEAVY AT TIMES PRODUCING POOR VISIBILITY.
INCREASING SOUTHEAST WINDS 20-25 SUSTAINED AND 40 KNOT GUSTS.  WINDS
SHOULD SHIFT TO SOUTH WEDNESDAY NIGHT AND SOUTHWEST TOWARD THURSDAY
MORNING. RAIN WILL TAPER OFF WITH THE WIND SHIFT TO SOUTHWEST. SEAS
WILL CONTINUE TO BUILD WITH 5-10 FEET HEIGHTS ON THE EXPOSED WATERS.
A GALE WARNING MAY BE NEEDED.

CHRISTMAS DAY... WEST SOUTHWEST WINDS WILL CONTINUE TO GUST 35-40
KNOTS...SO A GALE WARNING MAY CONTINUE TO BE NEEDED. SEAS OF 10-15
FEET ARE POSSIBLE ON THE EXPOSED WATERS...AND 5 FEET IS POSSIBLE ON
SOME OF THE NEARSHORE WATERS.

&&

.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES WILL OCCUR
TUESDAY THROUGH THURSDAY. BREAKING IT DOWN...ON TUESDAY HIGH TIDE
AT BOSTON WILL BE 11.6 FT. THERE WILL BE EAST WINDS DURING THIS
HIGH TIDE ALLOWING FOR MINOR SPLASHOVER ALONG THE MASS COAST. IF
WIND GUSTS INCREASE THEN COULD POSSIBLE SEE MINOR COASTAL
FLOODING.

ON WEDNESDAY...WINDS WILL SWITCH TO A MORE SOUTHEASTERLY FLOW DURING
THE DAY AND INCREASE QUICKLY DUE TO THE APPROACHING SYSTEM.
WEDNESDAY AFTERNOON HIGH TIDE IN BOSTON IS 11.7 FT...AND AN
APPRECIABLE EAST OR SOUTHEAST WIND SHOULD PUSH LEVELS HIGHER THAN ON
TUESDAY.  THIS WOULD PROBABLY BE THE BEST CHACNE OF MINOR COASTAL
FLOODING ALONG THE EAST COAST.

THE WEDNESDAY EVENING HIGH TIDE WILL BE A LITTLE LOWER...BUT THE
WIND BECOMES SOUTH WITH 50-60 KNOTS AT 2000 FEET ABOVE THE SURFACE
AVAILABLE TO BE BROUGHT DOWN IN GUSTS. HIGH TIDE IN PROVIDENCE WILL
BE 5.2 FT. MINOR COASTAL FLOODING COULD OCCUR ALONG THE SOUTH
COASTS OF RI AND MASS...AND COULD BE CHANNELED IN NORTH-SOUTH AXIS
BAYS SUCH AS NARRAGANSETT BAY.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.

&&

$$ SYNOPSIS...WTB/RLG
NEAR TERM...FRANK
SHORT TERM...RLG
LONG TERM...WTB
AVIATION...WTB/RLG
MARINE...WTB/RLG
TIDES/COASTAL FLOODING...STAFF




000
FXUS61 KBOX 202357
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
657 PM EST SAT DEC 20 2014

.SYNOPSIS...
SCATTERED SNOW/RAIN SHOWERS WILL AFFECT THE REGION THROUGH SUN.
WEAK LOW PRESSURE WILL PASS SOUTH OF NEW ENGLAND BRINGING ANOTHER
PERIOD OF PRECIPITATION MONDAY NIGHT AND TUESDAY. A MUCH STRONGER
STORM PASSING WEST OF NEW ENGLAND WILL BRING HEAVY
RAINFALL...GUSTY WINDS AND COASTAL FLOODING CONCERNS TO THE REGION
WEDNESDAY AND WEDNESDAY NIGHT. DRY BUT VERY WINDY CONDITIONS
FOLLOW FOR CHRISTMAS DAY.

&&

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

630 PM UPDATE...
COASTAL BOUNDARY ALONG EAST COASTAL MASS. WINDS ARE EAST-NORTHEAST
AT MARSHFIELD...HYANNIS AND PROVINCETOWN. WINDS ARE NORTH TO
NORTHWEST AT BOSTON...PLYMOUTH AIRPORT...OTIS ANG BASE. DEWPOINTS
ARE IN THE 30S EAST OF THE BOUNDARY AND 20S TO THE WEST. THE
CONVERGENCE ALONG THIS LINE AND MOIST INFLOW OFF THE OCEAN ARE
SERVING TO MAINTAIN RAIN/SNOW SHOWERS FROM SOUTH BOSTON TO THE
CAPE AND ISLANDS. THE WHOLE AREA IS MOVING WEST AND WILL MOVE
ACROSS THE REMAINDER OF SOUTHEAST MASS AND RI EARLY TONIGHT.

REPORT OF SNOW AT BEVERLY MASS EARLIER THIS EVENING. THERE WASN/T
MUCH TO SPEAK OF ON THE BOX RADAR...BUT TERMINAL DOPPLER A FEW
MILES FARTHER NORTH WAS ABLE TO SEE SOME LIGHT ECHOES AT THE TIME.
THESE HAVE SINCE DISSIPATED.

WE HAVE KEPT THE FORECAST MOSTLY INTACT FROM 4 PM. THE MOIST FLOW
WILL KEEP CLOUDS OVERHEAD. RAIN/SNOW SHOWERS SOUTH OF BOSTON WILL
SPREAD WEST OVERNIGHT. LINGERING CHANCE THAT ADDITIONAL SNOW
SHOWERS MOVE ASHORE THROUGH ESSEX COUNTY LATER IN THE NIGHT BUT
LOW CONFIDENCE ON THAT. ALSO LOW CONFIDENCE ON HOW MUCH REACHES
THE CT VALLEY.

PREVIOUS DISCUSSION...
AN INVERTED TROUGH WILL DEVELOP THIS EVENING IN RESPONSE TO A
SHORTWAVE MOVING ACROSS SOUTHERN NEW ENGLAND.  THIS WILL PROVIDE A
FOCUS FOR RAIN/SNOW SHOWERS ACROSS MUCH OF EASTERN MASSACHUSETTS
BEGINNING THIS AFTERNOON AND CONTINUING THROUGH TONIGHT.  WHILE SNOW
SHOWERS MAY REACH INTO WESTERN NEW ENGLAND TONIGHT...A COASTAL FRONT
WILL DEVELOP...AIDING IN FOCUSING SHOWERS ALONG THE EAST COAST OF
MASSACHUSETTS.

SNOW SHOWERS WILL BECOME MORE WIDESPREAD TONIGHT AS THE LOW LEVELS
MOISTEN UP A BIT MORE. LOOKS LIKE IT WILL LIKELY BE WARM ENOUGH
ACROSS THE CAPE AND SOUTHEASTERN PLYMOUTH COUNTY FOR SHOWERS TO BE
RAIN RATHER THAN SNOW.

OVERALL...EXPECTING 1-2 INCHES OF SNOW AT MOST ACROSS EASTERN
MASSACHUSETTS AND RHODE ISLAND.  THERE ARE SEVERAL POTENTIAL PLACES
WHERE LOCALIZED SLIGHTLY HIGHER AMOUNTS /POSSIBLY UP TO 2-4 INCHES/
ARE POSSIBLE.  LOOKING AT THE HIGH RES MODELS...EITHER ACROSS ESSEX
COUNTY AND CAPE ANN...EASTERN NORFOLK COUNTY INTO NORTHERN PLYMOUTH
COUNTY...OR BOTH. THEN THE HIGHER TERRAIN OF WORCESTER COUNTY AND
PROVIDENCE COUNTY MAY SEE SLIGHTLY HIGHER AMOUNTS GIVEN THE UPSLOPE
COMPONENT OF THE WINDS.

SOME OF THE HIGH RES MODELS HAVE A DECENT CLIP OF QPF INTO ESSEX
COUNTY...WHILE OTHERS HAVE NOTHING IN THE SAME AREA.  FOR NORFOLK
AND PLYMOUTH COUNTY...WE MAY SEE A BIT OF OCEAN ENHANCEMENT THAT
RAISES SNOW AMOUNTS IN THOSE AREAS.  DUE TO THE UNCERTAINTY AND THE
LOCALIZED NATURE OF THE POTENTIAL HIGHER AMOUNTS...AM OPTING NOT TO
ISSUE A WINTER WEATHER ADVISORY. INSTEAD...REISSUED THE SPECIAL
WEATHER STATEMENT FOR SNOW. ANYONE OUT AND ABOUT THIS EVENING IN
EASTERN MASSACHUSETTS WILL WANT TO USE CAUTION AS THERE MAY BE
SLIPPERY PATCHES.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
RAIN/SNOW SHOWERS WILL CONTINUE INTO THE MORNING HOURS...THEN TAPER
OFF AS INVERTED TROUGH PULLS AWAY FROM SOUTHERN NEW ENGLAND AND HIGH
PRESSURE STARTS TO BUILD IN.  MOST LIKELY AREAS FOR CONTINUING
SHOWERS WILL BE ALONG THE IMMEDIATE EAST COAST OF MASSACHUSETTS.

AS THE DAY GOES ON...EXPECT A SLOW DRYING TREND AS HIGH PRESSURE
BUILDS INTO THE REGION.  CLOUDS WILL STICK AROUND WITH TEMPS
GENERALLY IN THE 30S.

&&

.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
BIG PICTURE... SHORTWAVE ENTERING THE PACIFIC NORTHWEST CROSSES THE
ROCKIES OVER THE WEEKEND DRIVEN BY A 160-KNOT JET.  THIS DIGS A
SUBSTANTIAL TROUGH OVER THE PLAINS MONDAY-TUESDAY WHILE PACIFIC HIGH
PRESSURE BUILDS ALONG THE PACIFIC COAST. THIS IN TURN WILL ALLOW AN
UPPER RIDGE TO BUILD ALONG THE ATLANTIC COAST AND SLOWLY SHIFT EAST
OF THE COAST.  THE JET ENERGY WORKS ITS WAY AROUND THE BASE OF THE
PLAINS TROUGH AND MOVES UP THE APPALACHANS MIDWEEK.  THIS SUPPORTS A
TRANSITION OF THE TROUGH TO NEGATIVE TILT AND SLOWER MOVEMENT...WITH
WARM MOIST AIR FOR THE ATLANTIC COAST. THE TROUGH AXIS SWINGS OVER
NEW ENGLAND CHRISTMAS DAY FOLLOWED BY A WEAK RIDGE. ANOTHER
SHORTWAVE MOVES ASHORE FROM THE PACIFIC MIDWEEK AND MOVES ACROSS THE
PLAINS BY THE END OF THE WEEK AND APPROACHES THE NORTHEAST USA
SATURDAY.

THERE IS SOME SPREAD IN DETAILS AMONG THE LONG RANGE MODELS...BUT
ALL SHOW A SIMILAR SCENARIO BOTH FOR THE MIDWEEK SYSTEM AND THE END
OF WEEK SYSTEM.  WE USED A BLEND OF GFS/ECMWF.

THE DAILIES...

SUNDAY NIGHT-MONDAY... HIGH PRESSURE REMAINS NORTH OF THE REGION
BRINGING A MOIST EAST FLOW ACROSS SOUTHERN NEW ENGLAND. UPPER
PATTERN SHOWS WEAK RIDGING AS THE PLAINS TROUGH DIGS...BUT SURFACE
FIELDS SUGGEST A LINGERING INVERTED TROUGH ALONG OR JUST OFFSHORE.
THIS SHOULD MAINTAIN CONSIDERABLE CLOUDS. COULD BE SOME DRIZZLE OR
FLURRIES NEAR THE EAST COAST BUT SUPPORTING LARGE SCALE ASCENT IS
LACKING SO PCPN SHOULD BE LIMITED.

MONDAY NIGHT-TUESDAY... LOW PRESSURE FORMS ALONG A STALLED WARM
FRONT OFF THE MID ATLANTIC COAST. AS THE LOW DEVELOPS...IT BRINGS
AN INCREASED PRESSURE GRADIENT AGAINST HIGH PRESSURE MOVING
THROUGH THE MARITIMES. THE RESULT WILL BE A STRENGTHENING LOW
LEVEL EAST- SOUTHEAST JET. THIS WILL INCREASE THE MOIST INFLOW
OVER SOUTHERN NEW ENGLAND. ALSO...AS THE JET CONVERGES ON THE
INVERTED SURFACE TROUGH IT WILL GENERATE INCREASED LOW LEVEL LIFT
AND INCREASE THE CHANCE OF PCPN. WE WILL HAVE CLOUDS AND CHANCE
POPS. TEMPS IN NORTHWEST MASS WILL BE COLD ENOUGH SO THAT THERE
MAY BE A MIX OF PCPN TYPES DURING THE MORNING.

TUESDAY NIGHT-WEDNESDAY... PLAINS UPPER TROUGH DIGS DEEPER AND MOVES
EAST...PUSHING THE UPPER RIDGE TO OUR EAST. ALSO...THE STRONG UPPER
SOUTHWEST JET MOVES UP OVER THE EASTERN USA. THIS SETUP WILL TAKE
THE PRIMARY SURFACE LOW UP THROUGH THE WESTERN GREAT LAKES.
SECONDARY LOWS FORMING ON THE SYSTEM COLD FRONT WILL MOVE OUT OF THE
GULF OF MEXICO TOWARD THE GREAT LAKES. A SOUTHWEST LOW LEVEL JET
WILL MOVE UP THE ATLANTIC COAST ON WEDNESDAY AND OVER THE TOP OF THE
EAST-SOUTHEAST FLOW AT THE SURFACE. THE RESULT WILL BE PLENTY OF LOW
LEVEL LIFT THE GENERATE PCPN.

PRECIPITABLE WATER VALUES ARE FORECAST TO EXCEED 1.5 INCHES...WHICH
IS 3 STD DEVIATIONS ABOVE NORMAL FOR DECEMBER.  THIS MEANS A LOT OF
WATER AVAILABLE AS PCPN. TEMPERATURE PROFILES WILL BE ABOVE FREEZING
SO PTYPE SHOULD BE RAIN. MODEL QPF SHOWS POTENTIAL RAINFALL OF OVER
2 INCHES. THIS WOULD SUGGEST POTENTIAL URBAN/POOR DRAINAGE FLOODING
ISSUES WEDNESDAY.

STRONG LOW LEVEL WINDS WILL ALSO BE A CONCERN ESPECIALLY WEDNESDAY
NIGHT. THE ECMWF SHOWS EAST-SOUTHEAST WINDS 30-35 KNOTS ALONG HE
EAST MASS COAST AT 1000 MB. THEN WEDNESDAY NIGHT WINDS AT 925 MB
INCREASE TO 60-75 KNOTS AND MOVE ACROSS COASTAL RI AND SOUTHEAST
MASS. STRONG DOWNPOURS MAY OVERCOME THE LOW LEVEL INVERSION AND
BRING STRONG GUSTS OF AT LEAST 30-40 KNOTS ESPECIALLY ALONG THE
SOUTH COAST. A WIND ADVISORY MAY BE NEEDED IN SOME AREAS.

MAINTAINED A LIMITED MENTION OF THUNDER...AS CONVECTIVE PARAMETERS
ARE MARGINAL...SI VALUES WILL BE JUST ABOVE ZERO AND K INDEX WILL BE
IN THE LOW 30S WEDNESDAY NIGHT.

UPPER LOW WILL SWING THE SURFACE COLD FRONT THROUGH SOUTHERN NEW
ENGLAND WEDNESDAY NIGHT. WINDS WILL THEN SHIFT TO WEST AND PCPN
SHOULD COME TO AN END AROUND THE TIME THAT SANTA ARRIVES.

CHRISTMAS DAY... WEST WINDS WILL BRING A DRYING OF THE AIRMASS
DURING THE DAY. SO THE TREND SHOULD BE TO AT LEAST PARTIAL CLEARING.
SUFFICIENT COLD ADVECTION AT ALL LEVELS THURSDAY WILL ALLOW SOME
MIXING.  WINDS IN THE SFC-850 MB LAYER WILL BE 30-40 KNOTS AND
POSSIBLY A LITTLE HIGHER...WHICH WOULD REQUIRE A WIND ADVISORY FOR
MUCH OF THE AREA.

FRIDAY-SATURDAY... WEAK HIGH PRESSURE BUILDS OVER THE AREA FRIDAY
AND BRING A SUNNY DAY. THE NEXT PACIFIC SHORTWAVE APPROACHES
SATURDAY AND SHOULD BRING INCREASING CLOUDS FROM WEST TO EAST ALONG
WITH A CHANCE OF RAIN OR SNOW SHOWERS MAINLY IN THE AFTERNOON AND AT
NIGHT.

&&

.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 SUNDAY/...

TONIGHT AND SUNDAY...MVFR CIGS/VSBYS IN RAIN/SNOW SHOWERS MOVING
WEST OFF THE OCEAN INTO SOUTHEASTERN MASS. THESE WILL SPREAD
FARTHER WEST INTO RI/CENTRAL MASS/NORTHEAST CT. LOCAL IFR
CIGS/VSBYS POSSIBLE WITH THE STRONGEST SHOWERS.

WINDS ARE ENE ALONG THE IMMEDIATE SOUTHEAST MASS COAST WITH NORTH
TO NORTHWEST WINDS ELSEWHERE. THIS WINDSHIFT MAY NUDGE FARTHER
WEST WITH THE SHOWERS EARLY TONIGHT.

MVFR CIGS MAY REACH THE CT VALLEY LATE TONIGHT BUT LOW CONFIDENCE
ABOUT ANY SIGNIFICANT REDUCTION IN VSBY THERE.

MVFR CIGS WILL LINGER MOST AREA ON SUNDAY. ANY CIGS THAT RISE
ABOVE MVFR SHOULD ONLY REACH AROUND 4000 FEET.

KBOS TERMINAL...MODERATE CONFIDENCE IN TAF. FLURRIES AND SNOW
SHOWERS THROUGH 06Z WITH POTENTIAL FOR WINDSHIFT TO 040 DURING
THIS TIME.

KBDL TERMINAL...MODERATE CONFIDENCE IN TAF.

OUTLOOK...SUNDAY NIGHT THROUGH THURSDAY...MODERATE CONFIDENCE

SUNDAY NIGHT-MONDAY...MVFR CIGS CONTINUE IN RI/EASTERN MASS IN
MARINE EAST FLOW. VFR IN THE WEST.

TUESDAY...VFR WITH SCATTERED MVFR IN ANY RAIN/SNOW SHOWERS.

WEDNESDAY...CONDITIONS LOWERING TO IFR IN RAIN/HEAVY RAIN. ISOLATED
THUNDERSTORMS POSSIBLE ESPECIALLY WEDNESDAY NIGHT. EAST-SOUTHEST
SURFACE WINDS MAY GUST TO 35 KNOTS ALONG THE EAST MASSACHUSETTS
COAST. WINDS AT 2000 FEET AGL WILL REACH 50-60 KNOTS WEDNESDAY
AFTERNOON AND EARLY NIGHT CREATING LOW LEVEL WIND SHEAR CONCERNS.

CHRISTMAS DAY...WEST WIND GUSTING 30-40 KNOTS. CONDITIONS IMPROVING
TO VFR AS THE WIND BRINGS IN COOLER DRIER AIR.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

HIGH CONFIDENCE. HIGH PRESSURE ACROSS QUEBEC WILL RESULT IN
PERSISTENT NORTHEAST WINDS ACROSS THE WATERS THROUGH THE WEEKEND.
WIND GUSTS UP TO 20 KNOTS WITH SEAS BETWEEN 2 AND 4 FEET ARE
EXPECTED FOR MOST WATERS...SO NO HEADLINES PLANNED.

THERE IS A LOW PROBABILITY THAT A BRIEF SURGE OF NORTHEAST WIND
GUSTS NEAR 25 KNOTS WITH MARGINAL 5 FOOT SEAS COULD AFFECT OUR
NORTHERN WATERS LATE TONIGHT INTO SUN MORNING...BUT NOT CONFIDENT
ENOUGH TO ISSUE ANY HEADLINES AT THIS POINT.

OUTLOOK...SUNDAY NIGHT THROUGH THURSDAY...MODERATE CONFIDENCE

SUNDAY NIGHT-MONDAY...EAST TO NORTHEAST WINDS GUSTING AROUND 15
KNOTS OR LESS.  SEAS WILL HOLD AROUND 3-4 FEET.

TUESDAY... INCREASING EAST WINDS WITH FREQUENT GUSTS 25 TO 30 KNOTS.
SEAS WILL BUILD TO 5-6 FEET ON THE EXPOSED WATERS.  A SMALL CRAFT
ADVISORY MAY BE NEEDED.

WEDNESDAY...RAIN WILL BE HEAVY AT TIMES PRODUCING POOR VISIBILITY.
INCREASING SOUTHEAST WINDS 20-25 SUSTAINED AND 40 KNOT GUSTS.  WINDS
SHOULD SHIFT TO SOUTH WEDNESDAY NIGHT AND SOUTHWEST TOWARD THURSDAY
MORNING. RAIN WILL TAPER OFF WITH THE WIND SHIFT TO SOUTHWEST. SEAS
WILL CONTINUE TO BUILD WITH 5-10 FEET HEIGHTS ON THE EXPOSED WATERS.
A GALE WARNING MAY BE NEEDED.

CHRISTMAS DAY... WEST SOUTHWEST WINDS WILL CONTINUE TO GUST 35-40
KNOTS...SO A GALE WARNING MAY CONTINUE TO BE NEEDED. SEAS OF 10-15
FEET ARE POSSIBLE ON THE EXPOSED WATERS...AND 5 FEET IS POSSIBLE ON
SOME OF THE NEARSHORE WATERS.

&&

.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES WILL OCCUR
TUESDAY THROUGH THURSDAY. BREAKING IT DOWN...ON TUESDAY HIGH TIDE
AT BOSTON WILL BE 11.6 FT. THERE WILL BE EAST WINDS DURING THIS
HIGH TIDE ALLOWING FOR MINOR SPLASHOVER ALONG THE MASS COAST. IF
WIND GUSTS INCREASE THEN COULD POSSIBLE SEE MINOR COASTAL
FLOODING.

ON WEDNESDAY...WINDS WILL SWITCH TO A MORE SOUTHEASTERLY FLOW DURING
THE DAY AND INCREASE QUICKLY DUE TO THE APPROACHING SYSTEM.
WEDNESDAY AFTERNOON HIGH TIDE IN BOSTON IS 11.7 FT...AND AN
APPRECIABLE EAST OR SOUTHEAST WIND SHOULD PUSH LEVELS HIGHER THAN ON
TUESDAY.  THIS WOULD PROBABLY BE THE BEST CHACNE OF MINOR COASTAL
FLOODING ALONG THE EAST COAST.

THE WEDNESDAY EVENING HIGH TIDE WILL BE A LITTLE LOWER...BUT THE
WIND BECOMES SOUTH WITH 50-60 KNOTS AT 2000 FEET ABOVE THE SURFACE
AVAILABLE TO BE BROUGHT DOWN IN GUSTS. HIGH TIDE IN PROVIDENCE WILL
BE 5.2 FT. MINOR COASTAL FLOODING COULD OCCUR ALONG THE SOUTH
COASTS OF RI AND MASS...AND COULD BE CHANNELED IN NORTH-SOUTH AXIS
BAYS SUCH AS NARRAGANSETT BAY.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...WTB/RLG
NEAR TERM...WTB/RLG
SHORT TERM...RLG
LONG TERM...WTB
AVIATION...WTB/RLG
MARINE...WTB/RLG
TIDES/COASTAL FLOODING...




000
FXUS61 KBOX 202357
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
657 PM EST SAT DEC 20 2014

.SYNOPSIS...
SCATTERED SNOW/RAIN SHOWERS WILL AFFECT THE REGION THROUGH SUN.
WEAK LOW PRESSURE WILL PASS SOUTH OF NEW ENGLAND BRINGING ANOTHER
PERIOD OF PRECIPITATION MONDAY NIGHT AND TUESDAY. A MUCH STRONGER
STORM PASSING WEST OF NEW ENGLAND WILL BRING HEAVY
RAINFALL...GUSTY WINDS AND COASTAL FLOODING CONCERNS TO THE REGION
WEDNESDAY AND WEDNESDAY NIGHT. DRY BUT VERY WINDY CONDITIONS
FOLLOW FOR CHRISTMAS DAY.

&&

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

630 PM UPDATE...
COASTAL BOUNDARY ALONG EAST COASTAL MASS. WINDS ARE EAST-NORTHEAST
AT MARSHFIELD...HYANNIS AND PROVINCETOWN. WINDS ARE NORTH TO
NORTHWEST AT BOSTON...PLYMOUTH AIRPORT...OTIS ANG BASE. DEWPOINTS
ARE IN THE 30S EAST OF THE BOUNDARY AND 20S TO THE WEST. THE
CONVERGENCE ALONG THIS LINE AND MOIST INFLOW OFF THE OCEAN ARE
SERVING TO MAINTAIN RAIN/SNOW SHOWERS FROM SOUTH BOSTON TO THE
CAPE AND ISLANDS. THE WHOLE AREA IS MOVING WEST AND WILL MOVE
ACROSS THE REMAINDER OF SOUTHEAST MASS AND RI EARLY TONIGHT.

REPORT OF SNOW AT BEVERLY MASS EARLIER THIS EVENING. THERE WASN/T
MUCH TO SPEAK OF ON THE BOX RADAR...BUT TERMINAL DOPPLER A FEW
MILES FARTHER NORTH WAS ABLE TO SEE SOME LIGHT ECHOES AT THE TIME.
THESE HAVE SINCE DISSIPATED.

WE HAVE KEPT THE FORECAST MOSTLY INTACT FROM 4 PM. THE MOIST FLOW
WILL KEEP CLOUDS OVERHEAD. RAIN/SNOW SHOWERS SOUTH OF BOSTON WILL
SPREAD WEST OVERNIGHT. LINGERING CHANCE THAT ADDITIONAL SNOW
SHOWERS MOVE ASHORE THROUGH ESSEX COUNTY LATER IN THE NIGHT BUT
LOW CONFIDENCE ON THAT. ALSO LOW CONFIDENCE ON HOW MUCH REACHES
THE CT VALLEY.

PREVIOUS DISCUSSION...
AN INVERTED TROUGH WILL DEVELOP THIS EVENING IN RESPONSE TO A
SHORTWAVE MOVING ACROSS SOUTHERN NEW ENGLAND.  THIS WILL PROVIDE A
FOCUS FOR RAIN/SNOW SHOWERS ACROSS MUCH OF EASTERN MASSACHUSETTS
BEGINNING THIS AFTERNOON AND CONTINUING THROUGH TONIGHT.  WHILE SNOW
SHOWERS MAY REACH INTO WESTERN NEW ENGLAND TONIGHT...A COASTAL FRONT
WILL DEVELOP...AIDING IN FOCUSING SHOWERS ALONG THE EAST COAST OF
MASSACHUSETTS.

SNOW SHOWERS WILL BECOME MORE WIDESPREAD TONIGHT AS THE LOW LEVELS
MOISTEN UP A BIT MORE. LOOKS LIKE IT WILL LIKELY BE WARM ENOUGH
ACROSS THE CAPE AND SOUTHEASTERN PLYMOUTH COUNTY FOR SHOWERS TO BE
RAIN RATHER THAN SNOW.

OVERALL...EXPECTING 1-2 INCHES OF SNOW AT MOST ACROSS EASTERN
MASSACHUSETTS AND RHODE ISLAND.  THERE ARE SEVERAL POTENTIAL PLACES
WHERE LOCALIZED SLIGHTLY HIGHER AMOUNTS /POSSIBLY UP TO 2-4 INCHES/
ARE POSSIBLE.  LOOKING AT THE HIGH RES MODELS...EITHER ACROSS ESSEX
COUNTY AND CAPE ANN...EASTERN NORFOLK COUNTY INTO NORTHERN PLYMOUTH
COUNTY...OR BOTH. THEN THE HIGHER TERRAIN OF WORCESTER COUNTY AND
PROVIDENCE COUNTY MAY SEE SLIGHTLY HIGHER AMOUNTS GIVEN THE UPSLOPE
COMPONENT OF THE WINDS.

SOME OF THE HIGH RES MODELS HAVE A DECENT CLIP OF QPF INTO ESSEX
COUNTY...WHILE OTHERS HAVE NOTHING IN THE SAME AREA.  FOR NORFOLK
AND PLYMOUTH COUNTY...WE MAY SEE A BIT OF OCEAN ENHANCEMENT THAT
RAISES SNOW AMOUNTS IN THOSE AREAS.  DUE TO THE UNCERTAINTY AND THE
LOCALIZED NATURE OF THE POTENTIAL HIGHER AMOUNTS...AM OPTING NOT TO
ISSUE A WINTER WEATHER ADVISORY. INSTEAD...REISSUED THE SPECIAL
WEATHER STATEMENT FOR SNOW. ANYONE OUT AND ABOUT THIS EVENING IN
EASTERN MASSACHUSETTS WILL WANT TO USE CAUTION AS THERE MAY BE
SLIPPERY PATCHES.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
RAIN/SNOW SHOWERS WILL CONTINUE INTO THE MORNING HOURS...THEN TAPER
OFF AS INVERTED TROUGH PULLS AWAY FROM SOUTHERN NEW ENGLAND AND HIGH
PRESSURE STARTS TO BUILD IN.  MOST LIKELY AREAS FOR CONTINUING
SHOWERS WILL BE ALONG THE IMMEDIATE EAST COAST OF MASSACHUSETTS.

AS THE DAY GOES ON...EXPECT A SLOW DRYING TREND AS HIGH PRESSURE
BUILDS INTO THE REGION.  CLOUDS WILL STICK AROUND WITH TEMPS
GENERALLY IN THE 30S.

&&

.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
BIG PICTURE... SHORTWAVE ENTERING THE PACIFIC NORTHWEST CROSSES THE
ROCKIES OVER THE WEEKEND DRIVEN BY A 160-KNOT JET.  THIS DIGS A
SUBSTANTIAL TROUGH OVER THE PLAINS MONDAY-TUESDAY WHILE PACIFIC HIGH
PRESSURE BUILDS ALONG THE PACIFIC COAST. THIS IN TURN WILL ALLOW AN
UPPER RIDGE TO BUILD ALONG THE ATLANTIC COAST AND SLOWLY SHIFT EAST
OF THE COAST.  THE JET ENERGY WORKS ITS WAY AROUND THE BASE OF THE
PLAINS TROUGH AND MOVES UP THE APPALACHANS MIDWEEK.  THIS SUPPORTS A
TRANSITION OF THE TROUGH TO NEGATIVE TILT AND SLOWER MOVEMENT...WITH
WARM MOIST AIR FOR THE ATLANTIC COAST. THE TROUGH AXIS SWINGS OVER
NEW ENGLAND CHRISTMAS DAY FOLLOWED BY A WEAK RIDGE. ANOTHER
SHORTWAVE MOVES ASHORE FROM THE PACIFIC MIDWEEK AND MOVES ACROSS THE
PLAINS BY THE END OF THE WEEK AND APPROACHES THE NORTHEAST USA
SATURDAY.

THERE IS SOME SPREAD IN DETAILS AMONG THE LONG RANGE MODELS...BUT
ALL SHOW A SIMILAR SCENARIO BOTH FOR THE MIDWEEK SYSTEM AND THE END
OF WEEK SYSTEM.  WE USED A BLEND OF GFS/ECMWF.

THE DAILIES...

SUNDAY NIGHT-MONDAY... HIGH PRESSURE REMAINS NORTH OF THE REGION
BRINGING A MOIST EAST FLOW ACROSS SOUTHERN NEW ENGLAND. UPPER
PATTERN SHOWS WEAK RIDGING AS THE PLAINS TROUGH DIGS...BUT SURFACE
FIELDS SUGGEST A LINGERING INVERTED TROUGH ALONG OR JUST OFFSHORE.
THIS SHOULD MAINTAIN CONSIDERABLE CLOUDS. COULD BE SOME DRIZZLE OR
FLURRIES NEAR THE EAST COAST BUT SUPPORTING LARGE SCALE ASCENT IS
LACKING SO PCPN SHOULD BE LIMITED.

MONDAY NIGHT-TUESDAY... LOW PRESSURE FORMS ALONG A STALLED WARM
FRONT OFF THE MID ATLANTIC COAST. AS THE LOW DEVELOPS...IT BRINGS
AN INCREASED PRESSURE GRADIENT AGAINST HIGH PRESSURE MOVING
THROUGH THE MARITIMES. THE RESULT WILL BE A STRENGTHENING LOW
LEVEL EAST- SOUTHEAST JET. THIS WILL INCREASE THE MOIST INFLOW
OVER SOUTHERN NEW ENGLAND. ALSO...AS THE JET CONVERGES ON THE
INVERTED SURFACE TROUGH IT WILL GENERATE INCREASED LOW LEVEL LIFT
AND INCREASE THE CHANCE OF PCPN. WE WILL HAVE CLOUDS AND CHANCE
POPS. TEMPS IN NORTHWEST MASS WILL BE COLD ENOUGH SO THAT THERE
MAY BE A MIX OF PCPN TYPES DURING THE MORNING.

TUESDAY NIGHT-WEDNESDAY... PLAINS UPPER TROUGH DIGS DEEPER AND MOVES
EAST...PUSHING THE UPPER RIDGE TO OUR EAST. ALSO...THE STRONG UPPER
SOUTHWEST JET MOVES UP OVER THE EASTERN USA. THIS SETUP WILL TAKE
THE PRIMARY SURFACE LOW UP THROUGH THE WESTERN GREAT LAKES.
SECONDARY LOWS FORMING ON THE SYSTEM COLD FRONT WILL MOVE OUT OF THE
GULF OF MEXICO TOWARD THE GREAT LAKES. A SOUTHWEST LOW LEVEL JET
WILL MOVE UP THE ATLANTIC COAST ON WEDNESDAY AND OVER THE TOP OF THE
EAST-SOUTHEAST FLOW AT THE SURFACE. THE RESULT WILL BE PLENTY OF LOW
LEVEL LIFT THE GENERATE PCPN.

PRECIPITABLE WATER VALUES ARE FORECAST TO EXCEED 1.5 INCHES...WHICH
IS 3 STD DEVIATIONS ABOVE NORMAL FOR DECEMBER.  THIS MEANS A LOT OF
WATER AVAILABLE AS PCPN. TEMPERATURE PROFILES WILL BE ABOVE FREEZING
SO PTYPE SHOULD BE RAIN. MODEL QPF SHOWS POTENTIAL RAINFALL OF OVER
2 INCHES. THIS WOULD SUGGEST POTENTIAL URBAN/POOR DRAINAGE FLOODING
ISSUES WEDNESDAY.

STRONG LOW LEVEL WINDS WILL ALSO BE A CONCERN ESPECIALLY WEDNESDAY
NIGHT. THE ECMWF SHOWS EAST-SOUTHEAST WINDS 30-35 KNOTS ALONG HE
EAST MASS COAST AT 1000 MB. THEN WEDNESDAY NIGHT WINDS AT 925 MB
INCREASE TO 60-75 KNOTS AND MOVE ACROSS COASTAL RI AND SOUTHEAST
MASS. STRONG DOWNPOURS MAY OVERCOME THE LOW LEVEL INVERSION AND
BRING STRONG GUSTS OF AT LEAST 30-40 KNOTS ESPECIALLY ALONG THE
SOUTH COAST. A WIND ADVISORY MAY BE NEEDED IN SOME AREAS.

MAINTAINED A LIMITED MENTION OF THUNDER...AS CONVECTIVE PARAMETERS
ARE MARGINAL...SI VALUES WILL BE JUST ABOVE ZERO AND K INDEX WILL BE
IN THE LOW 30S WEDNESDAY NIGHT.

UPPER LOW WILL SWING THE SURFACE COLD FRONT THROUGH SOUTHERN NEW
ENGLAND WEDNESDAY NIGHT. WINDS WILL THEN SHIFT TO WEST AND PCPN
SHOULD COME TO AN END AROUND THE TIME THAT SANTA ARRIVES.

CHRISTMAS DAY... WEST WINDS WILL BRING A DRYING OF THE AIRMASS
DURING THE DAY. SO THE TREND SHOULD BE TO AT LEAST PARTIAL CLEARING.
SUFFICIENT COLD ADVECTION AT ALL LEVELS THURSDAY WILL ALLOW SOME
MIXING.  WINDS IN THE SFC-850 MB LAYER WILL BE 30-40 KNOTS AND
POSSIBLY A LITTLE HIGHER...WHICH WOULD REQUIRE A WIND ADVISORY FOR
MUCH OF THE AREA.

FRIDAY-SATURDAY... WEAK HIGH PRESSURE BUILDS OVER THE AREA FRIDAY
AND BRING A SUNNY DAY. THE NEXT PACIFIC SHORTWAVE APPROACHES
SATURDAY AND SHOULD BRING INCREASING CLOUDS FROM WEST TO EAST ALONG
WITH A CHANCE OF RAIN OR SNOW SHOWERS MAINLY IN THE AFTERNOON AND AT
NIGHT.

&&

.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 SUNDAY/...

TONIGHT AND SUNDAY...MVFR CIGS/VSBYS IN RAIN/SNOW SHOWERS MOVING
WEST OFF THE OCEAN INTO SOUTHEASTERN MASS. THESE WILL SPREAD
FARTHER WEST INTO RI/CENTRAL MASS/NORTHEAST CT. LOCAL IFR
CIGS/VSBYS POSSIBLE WITH THE STRONGEST SHOWERS.

WINDS ARE ENE ALONG THE IMMEDIATE SOUTHEAST MASS COAST WITH NORTH
TO NORTHWEST WINDS ELSEWHERE. THIS WINDSHIFT MAY NUDGE FARTHER
WEST WITH THE SHOWERS EARLY TONIGHT.

MVFR CIGS MAY REACH THE CT VALLEY LATE TONIGHT BUT LOW CONFIDENCE
ABOUT ANY SIGNIFICANT REDUCTION IN VSBY THERE.

MVFR CIGS WILL LINGER MOST AREA ON SUNDAY. ANY CIGS THAT RISE
ABOVE MVFR SHOULD ONLY REACH AROUND 4000 FEET.

KBOS TERMINAL...MODERATE CONFIDENCE IN TAF. FLURRIES AND SNOW
SHOWERS THROUGH 06Z WITH POTENTIAL FOR WINDSHIFT TO 040 DURING
THIS TIME.

KBDL TERMINAL...MODERATE CONFIDENCE IN TAF.

OUTLOOK...SUNDAY NIGHT THROUGH THURSDAY...MODERATE CONFIDENCE

SUNDAY NIGHT-MONDAY...MVFR CIGS CONTINUE IN RI/EASTERN MASS IN
MARINE EAST FLOW. VFR IN THE WEST.

TUESDAY...VFR WITH SCATTERED MVFR IN ANY RAIN/SNOW SHOWERS.

WEDNESDAY...CONDITIONS LOWERING TO IFR IN RAIN/HEAVY RAIN. ISOLATED
THUNDERSTORMS POSSIBLE ESPECIALLY WEDNESDAY NIGHT. EAST-SOUTHEST
SURFACE WINDS MAY GUST TO 35 KNOTS ALONG THE EAST MASSACHUSETTS
COAST. WINDS AT 2000 FEET AGL WILL REACH 50-60 KNOTS WEDNESDAY
AFTERNOON AND EARLY NIGHT CREATING LOW LEVEL WIND SHEAR CONCERNS.

CHRISTMAS DAY...WEST WIND GUSTING 30-40 KNOTS. CONDITIONS IMPROVING
TO VFR AS THE WIND BRINGS IN COOLER DRIER AIR.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

HIGH CONFIDENCE. HIGH PRESSURE ACROSS QUEBEC WILL RESULT IN
PERSISTENT NORTHEAST WINDS ACROSS THE WATERS THROUGH THE WEEKEND.
WIND GUSTS UP TO 20 KNOTS WITH SEAS BETWEEN 2 AND 4 FEET ARE
EXPECTED FOR MOST WATERS...SO NO HEADLINES PLANNED.

THERE IS A LOW PROBABILITY THAT A BRIEF SURGE OF NORTHEAST WIND
GUSTS NEAR 25 KNOTS WITH MARGINAL 5 FOOT SEAS COULD AFFECT OUR
NORTHERN WATERS LATE TONIGHT INTO SUN MORNING...BUT NOT CONFIDENT
ENOUGH TO ISSUE ANY HEADLINES AT THIS POINT.

OUTLOOK...SUNDAY NIGHT THROUGH THURSDAY...MODERATE CONFIDENCE

SUNDAY NIGHT-MONDAY...EAST TO NORTHEAST WINDS GUSTING AROUND 15
KNOTS OR LESS.  SEAS WILL HOLD AROUND 3-4 FEET.

TUESDAY... INCREASING EAST WINDS WITH FREQUENT GUSTS 25 TO 30 KNOTS.
SEAS WILL BUILD TO 5-6 FEET ON THE EXPOSED WATERS.  A SMALL CRAFT
ADVISORY MAY BE NEEDED.

WEDNESDAY...RAIN WILL BE HEAVY AT TIMES PRODUCING POOR VISIBILITY.
INCREASING SOUTHEAST WINDS 20-25 SUSTAINED AND 40 KNOT GUSTS.  WINDS
SHOULD SHIFT TO SOUTH WEDNESDAY NIGHT AND SOUTHWEST TOWARD THURSDAY
MORNING. RAIN WILL TAPER OFF WITH THE WIND SHIFT TO SOUTHWEST. SEAS
WILL CONTINUE TO BUILD WITH 5-10 FEET HEIGHTS ON THE EXPOSED WATERS.
A GALE WARNING MAY BE NEEDED.

CHRISTMAS DAY... WEST SOUTHWEST WINDS WILL CONTINUE TO GUST 35-40
KNOTS...SO A GALE WARNING MAY CONTINUE TO BE NEEDED. SEAS OF 10-15
FEET ARE POSSIBLE ON THE EXPOSED WATERS...AND 5 FEET IS POSSIBLE ON
SOME OF THE NEARSHORE WATERS.

&&

.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES WILL OCCUR
TUESDAY THROUGH THURSDAY. BREAKING IT DOWN...ON TUESDAY HIGH TIDE
AT BOSTON WILL BE 11.6 FT. THERE WILL BE EAST WINDS DURING THIS
HIGH TIDE ALLOWING FOR MINOR SPLASHOVER ALONG THE MASS COAST. IF
WIND GUSTS INCREASE THEN COULD POSSIBLE SEE MINOR COASTAL
FLOODING.

ON WEDNESDAY...WINDS WILL SWITCH TO A MORE SOUTHEASTERLY FLOW DURING
THE DAY AND INCREASE QUICKLY DUE TO THE APPROACHING SYSTEM.
WEDNESDAY AFTERNOON HIGH TIDE IN BOSTON IS 11.7 FT...AND AN
APPRECIABLE EAST OR SOUTHEAST WIND SHOULD PUSH LEVELS HIGHER THAN ON
TUESDAY.  THIS WOULD PROBABLY BE THE BEST CHACNE OF MINOR COASTAL
FLOODING ALONG THE EAST COAST.

THE WEDNESDAY EVENING HIGH TIDE WILL BE A LITTLE LOWER...BUT THE
WIND BECOMES SOUTH WITH 50-60 KNOTS AT 2000 FEET ABOVE THE SURFACE
AVAILABLE TO BE BROUGHT DOWN IN GUSTS. HIGH TIDE IN PROVIDENCE WILL
BE 5.2 FT. MINOR COASTAL FLOODING COULD OCCUR ALONG THE SOUTH
COASTS OF RI AND MASS...AND COULD BE CHANNELED IN NORTH-SOUTH AXIS
BAYS SUCH AS NARRAGANSETT BAY.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...WTB/RLG
NEAR TERM...WTB/RLG
SHORT TERM...RLG
LONG TERM...WTB
AVIATION...WTB/RLG
MARINE...WTB/RLG
TIDES/COASTAL FLOODING...





000
FXUS61 KBOX 202147
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
447 PM EST SAT DEC 20 2014

.SYNOPSIS...
SCATTERED SNOW/RAIN SHOWERS WILL GRADUALLY OVERSPREAD THE REGION
FROM EAST TO WEST THIS AFTERNOON THROUGH SUN. WEAK LOW PRESSURE
WILL PASS SOUTH OF NEW ENGLAND BRINGING ANOTHER PERIOD OF
PRECIPITATION MONDAY NIGHT AND TUESDAY. A MUCH STRONGER STORM
PASSING WEST OF NEW ENGLAND WILL BRING HEAVY RAINFALL...GUSTY
WINDS AND COASTAL FLOODING CONCERNS TO THE REGION WEDNESDAY
AND WEDNESDAY NIGHT. DRY BUT VERY WINDY CONDITIONS FOLLOW FOR
CHRISTMAS DAY.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AN INVERTED TROUGH WILL DEVELOP THIS EVENING IN RESPONSE TO A
SHORTWAVE MOVING ACROSS SOUTHERN NEW ENGLAND.  THIS WILL PROVIDE A
FOCUS FOR RAIN/SNOW SHOWERS ACROSS MUCH OF EASTERN MASSACHUSETTS
BEGINNING THIS AFTERNOON AND CONTINUING THROUGH TONIGHT.  WHILE SNOW
SHOWERS MAY REACH INTO WESTERN NEW ENGLAND TONIGHT...A COASTAL FRONT
WILL DEVELOP...AIDING IN FOCUSING SHOWERS ALONG THE EAST COAST OF
MASSACHUSETTS.

SNOW SHOWERS WILL BECOME MORE WIDESPREAD TONIGHT AS THE LOW LEVELS
MOISTEN UP A BIT MORE. LOOKS LIKE IT WILL LIKELY BE WARM ENOUGH
ACROSS THE CAPE AND SOUTHEASTERN PLYMOUTH COUNTY FOR SHOWERS TO BE
RAIN RATHER THAN SNOW.

OVERALL...EXPECTING 1-2 INCHES OF SNOW AT MOST ACROSS EASTERN
MASSACHUSETTS AND RHODE ISLAND.  THERE ARE SEVERAL POTENTIAL PLACES
WHERE LOCALIZED SLIGHTLY HIGHER AMOUNTS /POSSIBLY UP TO 2-4 INCHES/
ARE POSSIBLE.  LOOKING AT THE HIGH RES MODELS...EITHER ACROSS ESSEX
COUNTY AND CAPE ANN...EASTERN NORFOLK COUNTY INTO NORTHERN PLYMOUTH
COUNTY...OR BOTH. THEN THE HIGHER TERRAIN OF WORCESTER COUNTY AND
PROVIDENCE COUNTY MAY SEE SLIGHTLY HIGHER AMOUNTS GIVEN THE UPSLOPE
COMPONENT OF THE WINDS.

SOME OF THE HIGH RES MODELS HAVE A DECENT CLIP OF QPF INTO ESSEX
COUNTY...WHILE OTHERS HAVE NOTHING IN THE SAME AREA.  FOR NORFOLK
AND PLYMOUTH COUNTY...WE MAY SEE A BIT OF OCEAN ENHANCEMENT THAT
RAISES SNOW AMOUNTS IN THOSE AREAS.  DUE TO THE UNCERTAINTY AND THE
LOCALIZED NATURE OF THE POTENTIAL HIGHER AMOUNTS...AM OPTING NOT TO
ISSUE A WINTER WEATHER ADVISORY. INSTEAD...REISSUED THE SPECIAL
WEATHER STATEMENT FOR SNOW. ANYONE OUT AND ABOUT THIS EVENING IN
EASTERN MASSACHUSETTS WILL WANT TO USE CAUTION AS THERE MAY BE
SLIPPERY PATCHES.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
RAIN/SNOW SHOWERS WILL CONTINUE INTO THE MORNING HOURS...THEN TAPER
OFF AS INVERTED TROUGH PULLS AWAY FROM SOUTHERN NEW ENGLAND AND HIGH
PRESSURE STARTS TO BUILD IN.  MOST LIKELY AREAS FOR CONTINUING
SHOWERS WILL BE ALONG THE IMMEDIATE EAST COAST OF MASSACHUSETTS.

AS THE DAY GOES ON...EXPECT A SLOW DRYING TREND AS HIGH PRESSURE
BUILDS INTO THE REGION.  CLOUDS WILL STICK AROUND WITH TEMPS
GENERALLY IN THE 30S.

&&

.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...

BIG PICTURE... SHORTWAVE ENTERING THE PACIFIC NORTHWEST CROSSES THE
ROCKIES OVER THE WEEKEND DRIVEN BY A 160-KNOT JET.  THIS DIGS A
SUBSTANTIAL TROUGH OVER THE PLAINS MONDAY-TUESDAY WHILE PACIFIC HIGH
PRESSURE BUILDS ALONG THE PACIFIC COAST. THIS IN TURN WILL ALLOW AN
UPPER RIDGE TO BUILD ALONG THE ATLANTIC COAST AND SLOWLY SHIFT EAST
OF THE COAST.  THE JET ENERGY WORKS ITS WAY AROUND THE BASE OF THE
PLAINS TROUGH AND MOVES UP THE APPALACHANS MIDWEEK.  THIS SUPPORTS A
TRANSITION OF THE TROUGH TO NEGATIVE TILT AND SLOWER MOVEMENT...WITH
WARM MOIST AIR FOR THE ATLANTIC COAST. THE TROUGH AXIS SWINGS OVER
NEW ENGLAND CHRISTMAS DAY FOLLOWED BY A WEAK RIDGE. ANOTHER
SHORTWAVE MOVES ASHORE FROM THE PACIFIC MIDWEEK AND MOVES ACROSS THE
PLAINS BY THE END OF THE WEEK AND APPROACHES THE NORTHEAST USA
SATURDAY.

THERE IS SOME SPREAD IN DETAILS AMONG THE LONG RANGE MODELS...BUT
ALL SHOW A SIMILAR SCENARIO BOTH FOR THE MIDWEEK SYSTEM AND THE END
OF WEEK SYSTEM.  WE USED A BLEND OF GFS/ECMWF.

THE DAILIES...

SUNDAY NIGHT-MONDAY... HIGH PRESSURE REMAINS NORTH OF THE REGION
BRINGING A MOIST EAST FLOW ACROSS SOUTHERN NEW ENGLAND. UPPER
PATTERN SHOWS WEAK RIDGING AS THE PLAINS TROUGH DIGS...BUT SURFACE
FIELDS SUGGEST A LINGERING INVERTED TROUGH ALONG OR JUST OFFSHORE.
THIS SHOULD MAINTAIN CONSIDERABLE CLOUDS. COULD BE SOME DRIZZLE OR
FLURRIES NEAR THE EAST COAST BUT SUPPORTING LARGE SCALE ASCENT IS
LACKING SO PCPN SHOULD BE LIMITED.

MONDAY NIGHT-TUESDAY... LOW PRESSURE FORMS ALONG A STALLED WARM
FRONT OFF THE MID ATLANTIC COAST. AS THE LOW DEVELOPS...IT BRINGS
AN INCREASED PRESSURE GRADIENT AGAINST HIGH PRESSURE MOVING
THROUGH THE MARITIMES. THE RESULT WILL BE A STRENGTHENING LOW
LEVEL EAST- SOUTHEAST JET. THIS WILL INCREASE THE MOIST INFLOW
OVER SOUTHERN NEW ENGLAND. ALSO...AS THE JET CONVERGES ON THE
INVERTED SURFACE TROUGH IT WILL GENERATE INCREASED LOW LEVEL LIFT
AND INCREASE THE CHANCE OF PCPN. WE WILL HAVE CLOUDS AND CHANCE
POPS. TEMPS IN NORTHWEST MASS WILL BE COLD ENOUGH SO THAT THERE
MAY BE A MIX OF PCPN TYPES DURING THE MORNING.

TUESDAY NIGHT-WEDNESDAY... PLAINS UPPER TROUGH DIGS DEEPER AND MOVES
EAST...PUSHING THE UPPER RIDGE TO OUR EAST. ALSO...THE STRONG UPPER
SOUTHWEST JET MOVES UP OVER THE EASTERN USA. THIS SETUP WILL TAKE
THE PRIMARY SURFACE LOW UP THROUGH THE WESTERN GREAT LAKES.
SECONDARY LOWS FORMING ON THE SYSTEM COLD FRONT WILL MOVE OUT OF THE
GULF OF MEXICO TOWARD THE GREAT LAKES. A SOUTHWEST LOW LEVEL JET
WILL MOVE UP THE ATLANTIC COAST ON WEDNESDAY AND OVER THE TOP OF THE
EAST-SOUTHEAST FLOW AT THE SURFACE. THE RESULT WILL BE PLENTY OF LOW
LEVEL LIFT THE GENERATE PCPN.

PRECIPITABLE WATER VALUES ARE FORECAST TO EXCEED 1.5 INCHES...WHICH
IS 3 STD DEVIATIONS ABOVE NORMAL FOR DECEMBER.  THIS MEANS A LOT OF
WATER AVAILABLE AS PCPN. TEMPERATURE PROFILES WILL BE ABOVE FREEZING
SO PTYPE SHOULD BE RAIN. MODEL QPF SHOWS POTENTIAL RAINFALL OF OVER
2 INCHES. THIS WOULD SUGGEST POTENTIAL URBAN/POOR DRAINAGE FLOODING
ISSUES WEDNESDAY.

STRONG LOW LEVEL WINDS WILL ALSO BE A CONCERN ESPECIALLY WEDNESDAY
NIGHT. THE ECMWF SHOWS EAST-SOUTHEAST WINDS 30-35 KNOTS ALONG HE
EAST MASS COAST AT 1000 MB. THEN WEDNESDAY NIGHT WINDS AT 925 MB
INCREASE TO 60-75 KNOTS AND MOVE ACROSS COASTAL RI AND SOUTHEAST
MASS. STRONG DOWNPOURS MAY OVERCOME THE LOW LEVEL INVERSION AND
BRING STRONG GUSTS OF AT LEAST 30-40 KNOTS ESPECIALLY ALONG THE
SOUTH COAST. A WIND ADVISORY MAY BE NEEDED IN SOME AREAS.

MAINTAINED A LIMITED MENTION OF THUNDER...AS CONVECTIVE PARAMETERS
ARE MARGINAL...SI VALUES WILL BE JUST ABOVE ZERO AND K INDEX WILL BE
IN THE LOW 30S WEDNESDAY NIGHT.

UPPER LOW WILL SWING THE SURFACE COLD FRONT THROUGH SOUTHERN NEW
ENGLAND WEDNESDAY NIGHT. WINDS WILL THEN SHIFT TO WEST AND PCPN
SHOULD COME TO AN END AROUND THE TIME THAT SANTA ARRIVES.

CHRISTMAS DAY... WEST WINDS WILL BRING A DRYING OF THE AIRMASS
DURING THE DAY. SO THE TREND SHOULD BE TO AT LEAST PARTIAL CLEARING.
SUFFICIENT COLD ADVECTION AT ALL LEVELS THURSDAY WILL ALLOW SOME
MIXING.  WINDS IN THE SFC-850 MB LAYER WILL BE 30-40 KNOTS AND
POSSIBLY A LITTLE HIGHER...WHICH WOULD REQUIRE A WIND ADVISORY FOR
MUCH OF THE AREA.

FRIDAY-SATURDAY... WEAK HIGH PRESSURE BUILDS OVER THE AREA FRIDAY
AND BRING A SUNNY DAY. THE NEXT PACIFIC SHORTWAVE APPROACHES
SATURDAY AND SHOULD BRING INCREASING CLOUDS FROM WEST TO EAST ALONG
WITH A CHANCE OF RAIN OR SNOW SHOWERS MAINLY IN THE AFTERNOON AND AT
NIGHT.

&&

.AVIATION /22Z SATURDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /THROUGH SUNDAY/...

THROUGH 00Z...MODERATE CONFIDENCE. MVFR CIGS WILL CONTINUE TO
OVERSPREAD EASTERN NEW ENGLAND AND EVENTUALLY OVERSPREAD THE INTERIOR
THIS AFTERNOON. SCATTERED SHOWERS ACROSS PORTIONS OF EASTERN
MASSACHUSETTS THIS AFTERNOON. MAINLY SNOW SHOWERS TO THE NORTH AND
WEST OF CAPE COD CANAL...RAIN SHOWERS SOUTH AND EAST. LOCALIZED
IFR CONDITIONS POSSIBLE JUST INLAND FROM THE SOUTHEAST NEW ENGLAND
COAST...WHERE SNOW IS FALLING.

TONIGHT AND SUNDAY...MODERATE CONFIDENCE.  MVFR CONDITIONS DOMINATE
IN LOWER CLOUDS AND SCATTERED SHOWERS. LOCALIZED IFR CONDITIONS
POSSIBLE WITH THE BEST CHANCE IN SNOW SHOWERS. PRECIPITATION
AFFECTS MAINLY EASTERN NEW ENGLAND BUT STILL SOME SCATTERED
ACTIVITY ACROSS WESTERN NEW ENGLAND. MAINLY SNOW SHOWERS TO THE
NORTH AND WEST OF CAPE COD CANAL...RAIN SHOWERS SOUTH AND EAST.

KBOS TERMINAL...MODERATE CONFIDENCE IN TAF. FLURRIES AND SNOW
SHOWERS MAY AFFECT THE TERMINAL BY 21Z.

KBDL TERMINAL...MODERATE CONFIDENCE IN TAF.

OUTLOOK...SUNDAY NIGHT THROUGH THURSDAY...MODERATE CONFIDENCE

SUNDAY NIGHT-MONDAY...MVFR CIGS CONTINUE IN RI/EASTERN MASS IN
MARINE EAST FLOW. VFR IN THE WEST.

TUESDAY...VFR WITH SCATTERED MVFR IN ANY RAIN/SNOW SHOWERS.

WEDNESDAY...CONDITIONS LOWERING TO IFR IN RAIN/HEAVY RAIN. ISOLATED
THUNDERSTORMS POSSIBLE ESPECIALLY WEDNESDAY NIGHT. EAST-SOUTHEST
SURFACE WINDS MAY GUST TO 35 KNOTS ALONG THE EAST MASSACHUSETTS
COAST. WINDS AT 2000 FEET AGL WILL REACH 50-60 KNOTS WEDNESDAY
AFTERNOON AND EARLY NIGHT CREATING LOW LEVEL WIND SHEAR CONCERNS.

CHRISTMAS DAY...WEST WIND GUSTING 30-40 KNOTS. CONDITIONS IMPROVING
TO VFR AS THE WIND BRINGS IN COOLER DRIER AIR.
&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

HIGH CONFIDENCE. HIGH PRESSURE ACROSS QUEBEC WILL RESULT IN
PERSISTENT NORTHEAST WINDS ACROSS THE WATERS THROUGH THE WEEKEND.
WIND GUSTS UP TO 20 KNOTS WITH SEAS BETWEEN 2 AND 4 FEET ARE
EXPECTED FOR MOST WATERS...SO NO HEADLINES PLANNED.

THERE IS A LOW PROBABILITY THAT A BRIEF SURGE OF NORTHEAST WIND
GUSTS NEAR 25 KNOTS WITH MARGINAL 5 FOOT SEAS COULD AFFECT OUR
NORTHERN WATERS LATE TONIGHT INTO SUN MORNING...BUT NOT CONFIDENT
ENOUGH TO ISSUE ANY HEADLINES AT THIS POINT.

OUTLOOK...SUNDAY NIGHT THROUGH THURSDAY...MODERATE CONFIDENCE

SUNDAY NIGHT-MONDAY...EAST TO NORTHEAST WINDS GUSTING AROUND 15
KNOTS OR LESS.  SEAS WILL HOLD AROUND 3-4 FEET.

TUESDAY... INCREASING EAST WINDS WITH FREQUENT GUSTS 25 TO 30 KNOTS.
SEAS WILL BUILD TO 5-6 FEET ON THE EXPOSED WATERS.  A SMALL CRAFT
ADVISORY MAY BE NEEDED.

WEDNESDAY...RAIN WILL BE HEAVY AT TIMES PRODUCING POOR VISIBILITY.
INCREASING SOUTHEAST WINDS 20-25 SUSTAINED AND 40 KNOT GUSTS.  WINDS
SHOULD SHIFT TO SOUTH WEDNESDAY NIGHT AND SOUTHWEST TOWARD THURSDAY
MORNING. RAIN WILL TAPER OFF WITH THE WIND SHIFT TO SOUTHWEST. SEAS
WILL CONTINUE TO BUILD WITH 5-10 FEET HEIGHTS ON THE EXPOSED WATERS.
A GALE WARNING MAY BE NEEDED.

CHRISTMAS DAY... WEST SOUTHWEST WINDS WILL CONTINUE TO GUST 35-40
KNOTS...SO A GALE WARNING MAY CONTINUE TO BE NEEDED. SEAS OF 10-15
FEET ARE POSSIBLE ON THE EXPOSED WATERS...AND 5 FEET IS POSSIBLE ON
SOME OF THE NEARSHORE WATERS.

&&

.TIDES/COASTAL FLOODING... HIGH ASTRONOMICAL TIDES WILL OCCUR
TUESDAY THROUGH THURSDAY. BREAKING IT DOWN...ON TUESDAY HIGH TIDE
AT BOSTON WILL BE 11.6 FT. THERE WILL BE EAST WINDS DURING THIS
HIGH TIDE ALLOWING FOR MINOR SPLASHOVER ALONG THE MASS COAST. IF
WIND GUSTS INCREASE THEN COULD POSSIBLE SEE MINOR COASTAL
FLOODING.

ON WEDNESDAY...WINDS WILL SWITCH TO A MORE SOUTHEASTERLY FLOW DURING
THE DAY AND INCREASE QUICKLY DUE TO THE APPROACHING SYSTEM.
WEDNESDAY AFTERNOON HIGH TIDE IN BOSTON IS 11.7 FT...AND AN
APPRECIABLE EAST OR SOUTHEAST WIND SHOULD PUSH LEVELS HIGHER THAN ON
TUESDAY.  THIS WOULD PROBABLY BE THE BEST CHACNE OF MINOR COASTAL
FLOODING ALONG THE EAST COAST.

THE WEDNESDAY EVENING HIGH TIDE WILL BE A LITTLE LOWER...BUT THE
WIND BECOMES SOUTH WITH 50-60 KNOTS AT 2000 FEET ABOVE THE SURFACE
AVAILABLE TO BE BROUGHT DOWN IN GUSTS. HIGH TIDE IN PROVIDENCE WILL
BE 5.2 FT. MINOR COASTAL FLOODING COULD OCCUR ALONG THE SOUTH
COASTS OF RI AND MASS...AND COULD BE CHANNELED IN NORTH-SOUTH AXIS
BAYS SUCH AS NARRAGANSETT BAY.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...WTB/RLG
NEAR TERM...RLG
SHORT TERM...RLG
LONG TERM...WTB
AVIATION...WTB/RLG
MARINE...WTB/RLG
TIDES/COASTAL FLOODING...




000
FXUS61 KBOX 202147
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
447 PM EST SAT DEC 20 2014

.SYNOPSIS...
SCATTERED SNOW/RAIN SHOWERS WILL GRADUALLY OVERSPREAD THE REGION
FROM EAST TO WEST THIS AFTERNOON THROUGH SUN. WEAK LOW PRESSURE
WILL PASS SOUTH OF NEW ENGLAND BRINGING ANOTHER PERIOD OF
PRECIPITATION MONDAY NIGHT AND TUESDAY. A MUCH STRONGER STORM
PASSING WEST OF NEW ENGLAND WILL BRING HEAVY RAINFALL...GUSTY
WINDS AND COASTAL FLOODING CONCERNS TO THE REGION WEDNESDAY
AND WEDNESDAY NIGHT. DRY BUT VERY WINDY CONDITIONS FOLLOW FOR
CHRISTMAS DAY.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AN INVERTED TROUGH WILL DEVELOP THIS EVENING IN RESPONSE TO A
SHORTWAVE MOVING ACROSS SOUTHERN NEW ENGLAND.  THIS WILL PROVIDE A
FOCUS FOR RAIN/SNOW SHOWERS ACROSS MUCH OF EASTERN MASSACHUSETTS
BEGINNING THIS AFTERNOON AND CONTINUING THROUGH TONIGHT.  WHILE SNOW
SHOWERS MAY REACH INTO WESTERN NEW ENGLAND TONIGHT...A COASTAL FRONT
WILL DEVELOP...AIDING IN FOCUSING SHOWERS ALONG THE EAST COAST OF
MASSACHUSETTS.

SNOW SHOWERS WILL BECOME MORE WIDESPREAD TONIGHT AS THE LOW LEVELS
MOISTEN UP A BIT MORE. LOOKS LIKE IT WILL LIKELY BE WARM ENOUGH
ACROSS THE CAPE AND SOUTHEASTERN PLYMOUTH COUNTY FOR SHOWERS TO BE
RAIN RATHER THAN SNOW.

OVERALL...EXPECTING 1-2 INCHES OF SNOW AT MOST ACROSS EASTERN
MASSACHUSETTS AND RHODE ISLAND.  THERE ARE SEVERAL POTENTIAL PLACES
WHERE LOCALIZED SLIGHTLY HIGHER AMOUNTS /POSSIBLY UP TO 2-4 INCHES/
ARE POSSIBLE.  LOOKING AT THE HIGH RES MODELS...EITHER ACROSS ESSEX
COUNTY AND CAPE ANN...EASTERN NORFOLK COUNTY INTO NORTHERN PLYMOUTH
COUNTY...OR BOTH. THEN THE HIGHER TERRAIN OF WORCESTER COUNTY AND
PROVIDENCE COUNTY MAY SEE SLIGHTLY HIGHER AMOUNTS GIVEN THE UPSLOPE
COMPONENT OF THE WINDS.

SOME OF THE HIGH RES MODELS HAVE A DECENT CLIP OF QPF INTO ESSEX
COUNTY...WHILE OTHERS HAVE NOTHING IN THE SAME AREA.  FOR NORFOLK
AND PLYMOUTH COUNTY...WE MAY SEE A BIT OF OCEAN ENHANCEMENT THAT
RAISES SNOW AMOUNTS IN THOSE AREAS.  DUE TO THE UNCERTAINTY AND THE
LOCALIZED NATURE OF THE POTENTIAL HIGHER AMOUNTS...AM OPTING NOT TO
ISSUE A WINTER WEATHER ADVISORY. INSTEAD...REISSUED THE SPECIAL
WEATHER STATEMENT FOR SNOW. ANYONE OUT AND ABOUT THIS EVENING IN
EASTERN MASSACHUSETTS WILL WANT TO USE CAUTION AS THERE MAY BE
SLIPPERY PATCHES.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
RAIN/SNOW SHOWERS WILL CONTINUE INTO THE MORNING HOURS...THEN TAPER
OFF AS INVERTED TROUGH PULLS AWAY FROM SOUTHERN NEW ENGLAND AND HIGH
PRESSURE STARTS TO BUILD IN.  MOST LIKELY AREAS FOR CONTINUING
SHOWERS WILL BE ALONG THE IMMEDIATE EAST COAST OF MASSACHUSETTS.

AS THE DAY GOES ON...EXPECT A SLOW DRYING TREND AS HIGH PRESSURE
BUILDS INTO THE REGION.  CLOUDS WILL STICK AROUND WITH TEMPS
GENERALLY IN THE 30S.

&&

.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...

BIG PICTURE... SHORTWAVE ENTERING THE PACIFIC NORTHWEST CROSSES THE
ROCKIES OVER THE WEEKEND DRIVEN BY A 160-KNOT JET.  THIS DIGS A
SUBSTANTIAL TROUGH OVER THE PLAINS MONDAY-TUESDAY WHILE PACIFIC HIGH
PRESSURE BUILDS ALONG THE PACIFIC COAST. THIS IN TURN WILL ALLOW AN
UPPER RIDGE TO BUILD ALONG THE ATLANTIC COAST AND SLOWLY SHIFT EAST
OF THE COAST.  THE JET ENERGY WORKS ITS WAY AROUND THE BASE OF THE
PLAINS TROUGH AND MOVES UP THE APPALACHANS MIDWEEK.  THIS SUPPORTS A
TRANSITION OF THE TROUGH TO NEGATIVE TILT AND SLOWER MOVEMENT...WITH
WARM MOIST AIR FOR THE ATLANTIC COAST. THE TROUGH AXIS SWINGS OVER
NEW ENGLAND CHRISTMAS DAY FOLLOWED BY A WEAK RIDGE. ANOTHER
SHORTWAVE MOVES ASHORE FROM THE PACIFIC MIDWEEK AND MOVES ACROSS THE
PLAINS BY THE END OF THE WEEK AND APPROACHES THE NORTHEAST USA
SATURDAY.

THERE IS SOME SPREAD IN DETAILS AMONG THE LONG RANGE MODELS...BUT
ALL SHOW A SIMILAR SCENARIO BOTH FOR THE MIDWEEK SYSTEM AND THE END
OF WEEK SYSTEM.  WE USED A BLEND OF GFS/ECMWF.

THE DAILIES...

SUNDAY NIGHT-MONDAY... HIGH PRESSURE REMAINS NORTH OF THE REGION
BRINGING A MOIST EAST FLOW ACROSS SOUTHERN NEW ENGLAND. UPPER
PATTERN SHOWS WEAK RIDGING AS THE PLAINS TROUGH DIGS...BUT SURFACE
FIELDS SUGGEST A LINGERING INVERTED TROUGH ALONG OR JUST OFFSHORE.
THIS SHOULD MAINTAIN CONSIDERABLE CLOUDS. COULD BE SOME DRIZZLE OR
FLURRIES NEAR THE EAST COAST BUT SUPPORTING LARGE SCALE ASCENT IS
LACKING SO PCPN SHOULD BE LIMITED.

MONDAY NIGHT-TUESDAY... LOW PRESSURE FORMS ALONG A STALLED WARM
FRONT OFF THE MID ATLANTIC COAST. AS THE LOW DEVELOPS...IT BRINGS
AN INCREASED PRESSURE GRADIENT AGAINST HIGH PRESSURE MOVING
THROUGH THE MARITIMES. THE RESULT WILL BE A STRENGTHENING LOW
LEVEL EAST- SOUTHEAST JET. THIS WILL INCREASE THE MOIST INFLOW
OVER SOUTHERN NEW ENGLAND. ALSO...AS THE JET CONVERGES ON THE
INVERTED SURFACE TROUGH IT WILL GENERATE INCREASED LOW LEVEL LIFT
AND INCREASE THE CHANCE OF PCPN. WE WILL HAVE CLOUDS AND CHANCE
POPS. TEMPS IN NORTHWEST MASS WILL BE COLD ENOUGH SO THAT THERE
MAY BE A MIX OF PCPN TYPES DURING THE MORNING.

TUESDAY NIGHT-WEDNESDAY... PLAINS UPPER TROUGH DIGS DEEPER AND MOVES
EAST...PUSHING THE UPPER RIDGE TO OUR EAST. ALSO...THE STRONG UPPER
SOUTHWEST JET MOVES UP OVER THE EASTERN USA. THIS SETUP WILL TAKE
THE PRIMARY SURFACE LOW UP THROUGH THE WESTERN GREAT LAKES.
SECONDARY LOWS FORMING ON THE SYSTEM COLD FRONT WILL MOVE OUT OF THE
GULF OF MEXICO TOWARD THE GREAT LAKES. A SOUTHWEST LOW LEVEL JET
WILL MOVE UP THE ATLANTIC COAST ON WEDNESDAY AND OVER THE TOP OF THE
EAST-SOUTHEAST FLOW AT THE SURFACE. THE RESULT WILL BE PLENTY OF LOW
LEVEL LIFT THE GENERATE PCPN.

PRECIPITABLE WATER VALUES ARE FORECAST TO EXCEED 1.5 INCHES...WHICH
IS 3 STD DEVIATIONS ABOVE NORMAL FOR DECEMBER.  THIS MEANS A LOT OF
WATER AVAILABLE AS PCPN. TEMPERATURE PROFILES WILL BE ABOVE FREEZING
SO PTYPE SHOULD BE RAIN. MODEL QPF SHOWS POTENTIAL RAINFALL OF OVER
2 INCHES. THIS WOULD SUGGEST POTENTIAL URBAN/POOR DRAINAGE FLOODING
ISSUES WEDNESDAY.

STRONG LOW LEVEL WINDS WILL ALSO BE A CONCERN ESPECIALLY WEDNESDAY
NIGHT. THE ECMWF SHOWS EAST-SOUTHEAST WINDS 30-35 KNOTS ALONG HE
EAST MASS COAST AT 1000 MB. THEN WEDNESDAY NIGHT WINDS AT 925 MB
INCREASE TO 60-75 KNOTS AND MOVE ACROSS COASTAL RI AND SOUTHEAST
MASS. STRONG DOWNPOURS MAY OVERCOME THE LOW LEVEL INVERSION AND
BRING STRONG GUSTS OF AT LEAST 30-40 KNOTS ESPECIALLY ALONG THE
SOUTH COAST. A WIND ADVISORY MAY BE NEEDED IN SOME AREAS.

MAINTAINED A LIMITED MENTION OF THUNDER...AS CONVECTIVE PARAMETERS
ARE MARGINAL...SI VALUES WILL BE JUST ABOVE ZERO AND K INDEX WILL BE
IN THE LOW 30S WEDNESDAY NIGHT.

UPPER LOW WILL SWING THE SURFACE COLD FRONT THROUGH SOUTHERN NEW
ENGLAND WEDNESDAY NIGHT. WINDS WILL THEN SHIFT TO WEST AND PCPN
SHOULD COME TO AN END AROUND THE TIME THAT SANTA ARRIVES.

CHRISTMAS DAY... WEST WINDS WILL BRING A DRYING OF THE AIRMASS
DURING THE DAY. SO THE TREND SHOULD BE TO AT LEAST PARTIAL CLEARING.
SUFFICIENT COLD ADVECTION AT ALL LEVELS THURSDAY WILL ALLOW SOME
MIXING.  WINDS IN THE SFC-850 MB LAYER WILL BE 30-40 KNOTS AND
POSSIBLY A LITTLE HIGHER...WHICH WOULD REQUIRE A WIND ADVISORY FOR
MUCH OF THE AREA.

FRIDAY-SATURDAY... WEAK HIGH PRESSURE BUILDS OVER THE AREA FRIDAY
AND BRING A SUNNY DAY. THE NEXT PACIFIC SHORTWAVE APPROACHES
SATURDAY AND SHOULD BRING INCREASING CLOUDS FROM WEST TO EAST ALONG
WITH A CHANCE OF RAIN OR SNOW SHOWERS MAINLY IN THE AFTERNOON AND AT
NIGHT.

&&

.AVIATION /22Z SATURDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /THROUGH SUNDAY/...

THROUGH 00Z...MODERATE CONFIDENCE. MVFR CIGS WILL CONTINUE TO
OVERSPREAD EASTERN NEW ENGLAND AND EVENTUALLY OVERSPREAD THE INTERIOR
THIS AFTERNOON. SCATTERED SHOWERS ACROSS PORTIONS OF EASTERN
MASSACHUSETTS THIS AFTERNOON. MAINLY SNOW SHOWERS TO THE NORTH AND
WEST OF CAPE COD CANAL...RAIN SHOWERS SOUTH AND EAST. LOCALIZED
IFR CONDITIONS POSSIBLE JUST INLAND FROM THE SOUTHEAST NEW ENGLAND
COAST...WHERE SNOW IS FALLING.

TONIGHT AND SUNDAY...MODERATE CONFIDENCE.  MVFR CONDITIONS DOMINATE
IN LOWER CLOUDS AND SCATTERED SHOWERS. LOCALIZED IFR CONDITIONS
POSSIBLE WITH THE BEST CHANCE IN SNOW SHOWERS. PRECIPITATION
AFFECTS MAINLY EASTERN NEW ENGLAND BUT STILL SOME SCATTERED
ACTIVITY ACROSS WESTERN NEW ENGLAND. MAINLY SNOW SHOWERS TO THE
NORTH AND WEST OF CAPE COD CANAL...RAIN SHOWERS SOUTH AND EAST.

KBOS TERMINAL...MODERATE CONFIDENCE IN TAF. FLURRIES AND SNOW
SHOWERS MAY AFFECT THE TERMINAL BY 21Z.

KBDL TERMINAL...MODERATE CONFIDENCE IN TAF.

OUTLOOK...SUNDAY NIGHT THROUGH THURSDAY...MODERATE CONFIDENCE

SUNDAY NIGHT-MONDAY...MVFR CIGS CONTINUE IN RI/EASTERN MASS IN
MARINE EAST FLOW. VFR IN THE WEST.

TUESDAY...VFR WITH SCATTERED MVFR IN ANY RAIN/SNOW SHOWERS.

WEDNESDAY...CONDITIONS LOWERING TO IFR IN RAIN/HEAVY RAIN. ISOLATED
THUNDERSTORMS POSSIBLE ESPECIALLY WEDNESDAY NIGHT. EAST-SOUTHEST
SURFACE WINDS MAY GUST TO 35 KNOTS ALONG THE EAST MASSACHUSETTS
COAST. WINDS AT 2000 FEET AGL WILL REACH 50-60 KNOTS WEDNESDAY
AFTERNOON AND EARLY NIGHT CREATING LOW LEVEL WIND SHEAR CONCERNS.

CHRISTMAS DAY...WEST WIND GUSTING 30-40 KNOTS. CONDITIONS IMPROVING
TO VFR AS THE WIND BRINGS IN COOLER DRIER AIR.
&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

HIGH CONFIDENCE. HIGH PRESSURE ACROSS QUEBEC WILL RESULT IN
PERSISTENT NORTHEAST WINDS ACROSS THE WATERS THROUGH THE WEEKEND.
WIND GUSTS UP TO 20 KNOTS WITH SEAS BETWEEN 2 AND 4 FEET ARE
EXPECTED FOR MOST WATERS...SO NO HEADLINES PLANNED.

THERE IS A LOW PROBABILITY THAT A BRIEF SURGE OF NORTHEAST WIND
GUSTS NEAR 25 KNOTS WITH MARGINAL 5 FOOT SEAS COULD AFFECT OUR
NORTHERN WATERS LATE TONIGHT INTO SUN MORNING...BUT NOT CONFIDENT
ENOUGH TO ISSUE ANY HEADLINES AT THIS POINT.

OUTLOOK...SUNDAY NIGHT THROUGH THURSDAY...MODERATE CONFIDENCE

SUNDAY NIGHT-MONDAY...EAST TO NORTHEAST WINDS GUSTING AROUND 15
KNOTS OR LESS.  SEAS WILL HOLD AROUND 3-4 FEET.

TUESDAY... INCREASING EAST WINDS WITH FREQUENT GUSTS 25 TO 30 KNOTS.
SEAS WILL BUILD TO 5-6 FEET ON THE EXPOSED WATERS.  A SMALL CRAFT
ADVISORY MAY BE NEEDED.

WEDNESDAY...RAIN WILL BE HEAVY AT TIMES PRODUCING POOR VISIBILITY.
INCREASING SOUTHEAST WINDS 20-25 SUSTAINED AND 40 KNOT GUSTS.  WINDS
SHOULD SHIFT TO SOUTH WEDNESDAY NIGHT AND SOUTHWEST TOWARD THURSDAY
MORNING. RAIN WILL TAPER OFF WITH THE WIND SHIFT TO SOUTHWEST. SEAS
WILL CONTINUE TO BUILD WITH 5-10 FEET HEIGHTS ON THE EXPOSED WATERS.
A GALE WARNING MAY BE NEEDED.

CHRISTMAS DAY... WEST SOUTHWEST WINDS WILL CONTINUE TO GUST 35-40
KNOTS...SO A GALE WARNING MAY CONTINUE TO BE NEEDED. SEAS OF 10-15
FEET ARE POSSIBLE ON THE EXPOSED WATERS...AND 5 FEET IS POSSIBLE ON
SOME OF THE NEARSHORE WATERS.

&&

.TIDES/COASTAL FLOODING... HIGH ASTRONOMICAL TIDES WILL OCCUR
TUESDAY THROUGH THURSDAY. BREAKING IT DOWN...ON TUESDAY HIGH TIDE
AT BOSTON WILL BE 11.6 FT. THERE WILL BE EAST WINDS DURING THIS
HIGH TIDE ALLOWING FOR MINOR SPLASHOVER ALONG THE MASS COAST. IF
WIND GUSTS INCREASE THEN COULD POSSIBLE SEE MINOR COASTAL
FLOODING.

ON WEDNESDAY...WINDS WILL SWITCH TO A MORE SOUTHEASTERLY FLOW DURING
THE DAY AND INCREASE QUICKLY DUE TO THE APPROACHING SYSTEM.
WEDNESDAY AFTERNOON HIGH TIDE IN BOSTON IS 11.7 FT...AND AN
APPRECIABLE EAST OR SOUTHEAST WIND SHOULD PUSH LEVELS HIGHER THAN ON
TUESDAY.  THIS WOULD PROBABLY BE THE BEST CHACNE OF MINOR COASTAL
FLOODING ALONG THE EAST COAST.

THE WEDNESDAY EVENING HIGH TIDE WILL BE A LITTLE LOWER...BUT THE
WIND BECOMES SOUTH WITH 50-60 KNOTS AT 2000 FEET ABOVE THE SURFACE
AVAILABLE TO BE BROUGHT DOWN IN GUSTS. HIGH TIDE IN PROVIDENCE WILL
BE 5.2 FT. MINOR COASTAL FLOODING COULD OCCUR ALONG THE SOUTH
COASTS OF RI AND MASS...AND COULD BE CHANNELED IN NORTH-SOUTH AXIS
BAYS SUCH AS NARRAGANSETT BAY.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...WTB/RLG
NEAR TERM...RLG
SHORT TERM...RLG
LONG TERM...WTB
AVIATION...WTB/RLG
MARINE...WTB/RLG
TIDES/COASTAL FLOODING...





000
FXUS61 KBOX 202026
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
326 PM EST SAT DEC 20 2014

.SYNOPSIS...
SCATTERED SNOW/RAIN SHOWERS WILL GRADUALLY OVERSPREAD THE REGION
FROM EAST TO WEST THIS AFTERNOON THROUGH SUN. WEAK LOW PRESSURE
WILL PASS SOUTH OF NEW ENGLAND BRINGING ANOTHER PERIOD OF PRECIP
MON NIGHT AND TUE. A MUCH STRONGER STORM PASSING WEST OF NEW
ENGLAND WILL BRING HEAVY RAINFALL...GUSTY WINDS AND COASTAL
FLOODING CONCERNS TO THE REGION WED INTO WED EVENING. DRY BUT VERY
WINDY CONDITIONS FOLLOW FOR CHRISTMAS DAY INTO FRI.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AN INVERTED TROUGH WILL DEVELOP THIS EVENING IN RESPONSE TO A
SHORTWAVE MOVING ACROSS SOUTHERN NEW ENGLAND.  THIS WILL PROVIDE A
FOCUS FOR RAIN/SNOW SHOWERS ACROSS MUCH OF EASTERN MASSACHUSETTS
BEGINNING THIS AFTERNOON AND CONTINUING THROUGH TONIGHT.  WHILE SNOW
SHOWERS MAY REACH INTO WESTERN NEW ENGLAND TONIGHT...A COASTAL FRONT
WILL DEVELOP...AIDING IN FOCUSING SHOWERS ALONG THE EAST COAST OF
MASSACHUSETTS.

SNOW SHOWERS WILL BECOME MORE WIDESPREAD TONIGHT AS THE LOW LEVELS
MOISTEN UP A BIT MORE. LOOKS LIKE IT WILL LIKELY BE WARM ENOUGH
ACROSS THE CAPE AND SOUTHEASTERN PLYMOUTH COUNTY FOR SHOWERS TO BE
RAIN RATHER THAN SNOW.

OVERALL...EXPECTING 1-2 INCHES OF SNOW AT MOST ACROSS EASTERN
MASSACHUSETTS AND RHODE ISLAND.  THERE ARE SEVERAL POTENTIAL PLACES
WHERE LOCALIZED SLIGHTLY HIGHER AMOUNTS /POSSIBLY UP TO 2-4 INCHES/
ARE POSSIBLE.  LOOKING AT THE HIGH RES MODELS...EITHER ACROSS ESSEX
COUNTY AND CAPE ANN...EASTERN NORFOLK COUNTY INTO NORTHERN PLYMOUTH
COUNTY...OR BOTH. THEN THE HIGHER TERRAIN OF WORCESTER COUNTY AND
PROVIDENCE COUNTY MAY SEE SLIGHTLY HIGHER AMOUNTS GIVEN THE UPSLOPE
COMPONENT OF THE WINDS.

SOME OF THE HIGH RES MODELS HAVE A DECENT CLIP OF QPF INTO ESSEX
COUNTY...WHILE OTHERS HAVE NOTHING IN THE SAME AREA.  FOR NORFOLK
AND PLYMOUTH COUNTY...WE MAY SEE A BIT OF OCEAN ENHANCEMENT THAT
RAISES SNOW AMOUNTS IN THOSE AREAS.  DUE TO THE UNCERTAINTY AND THE
LOCALIZED NATURE OF THE POTENTIAL HIGHER AMOUNTS...AM OPTING NOT TO
ISSUE A WINTER WEATHER ADVISORY. INSTEAD...REISSUED THE SPECIAL
WEATHER STATEMENT FOR SNOW. ANYONE OUT AND ABOUT THIS EVENING IN
EASTERN MASSACHUSETTS WILL WANT TO USE CAUTION AS THERE MAY BE
SLIPPERY PATCHES.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
RAIN/SNOW SHOWERS WILL CONTINUE INTO THE MORNING HOURS...THEN TAPER
OFF AS INVERTED TROUGH PULLS AWAY FROM SOUTHERN NEW ENGLAND AND HIGH
PRESSURE STARTS TO BUILD IN.  MOST LIKELY AREAS FOR CONTINUING
SHOWERS WILL BE ALONG THE IMMEDIATE EAST COAST OF MASSACHUSETTS.

AS THE DAY GOES ON...EXPECT A SLOW DRYING TREND AS HIGH PRESSURE
BUILDS INTO THE REGION.  CLOUDS WILL STICK AROUND WITH TEMPS
GENERALLY IN THE 30S.

&&

.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
HIGHLIGHTS...

* INVERTED TROUGH WILL BRING RAIN/SNOW SHOWERS TO THE MASS EAST
  COASTLINE MONDAY INTO TUES MORNING.
* WEAK WAVE OF LOW PRESSURE MON NIGHT/TUESDAY COULD BRING WINTRY
  MIX TO INTERIOR
* ANOMALOUS SYSTEM ACROSS THE GREAT LAKES WILL BRING HEAVY
  RAIN...GUSTY WINDS AND COASTAL FLOODING CONCERNS AROUND CHRISTMAS
  EVE

OVERVIEW...

OVERALL 00Z GUIDANCE IS IN AGREEMENT SYNOPTICALLY WITH ISSUES ON
TIMING AND SMALLER SCALE FEATURES. IT REMAINS EVIDENT THAT AN
AMPLIFIED MID-UPPER LEVEL TROUGH AND PCPN FOCUSING LEAD SURFACE
LOW/FRONTAL SYSTEM WILL STEADILY PROGRESS TO THE EAST-CENTRAL U.S.
TUE AS EMBEDDED IMPULSES DIG TO THE LEE OF AN AMPLIFIED ERN
PACIFIC/WEST COAST RIDGE ALOFT. THE SUPPORTING AND INCREASINGLY
NEGATIVE-TILT TROUGH ALOFT WORKS OVER THE ERN US AND OUT THROUGH THE
NERN STATES INTO DAYS 4/5 WED/THU.  MODELS/ENSEMBLES HAVE BEEN
FAIRLY CONSISTENT ON THIS AMPLIFIED PATTERN AND THE MOST RECENT
GEFS/ECMWF ENSEMBLE GUIDANCE SHOW GOOD CORRELATION TO NEXT THURSDAY.

HIGH PRESSURE AND UPPER LEVEL RIDGE OVER THE REGION WILL BEGIN TO
EXIT BY MONDAY. AT THE SURFACE APPEARS ANOTHER INVERTED
TROUGH/ONSHORE FLOW WILL YIELD TO PRECIP ALONG THE MASS COASTLINE ON
MONDAY. ASIDE FROM THIS QUICK MESOSCALE EVENT THE MAIN FOCUS IS ON
THE LONGWAVE DIGGING TROUGH OVER THE CENTRAL CONUS WHICH WILL PUSH A
FEW SHORTWAVES THROUGH THE FLOW. FIRST ONE DEVELOPS A WEAK WAVE
MOVING TOWARDS THE REGION LATE MONDAY INTO TUESDAY. THERE IS STILL
SOME UNCERTAINTY WITH THE LOCATION/STRENGTH OF THIS SYSTEM BUT
APPEARS THAT THERE IS THE POSSIBILITY OF A SNOW/WINTRY MIX IN THE
INTERIOR. AS THIS SYSTEM DEPARTS AN ANOMALOUS LOW OVER THE GREAT
LAKES WILL DEVELOP A SECONDARY LOW JUST WEST OF SOUTHERN NEW ENGLAND
PER ENSEMBLE GUIDANCE. STILL A SOME SPREAD BUT IF THIS DOUBLE LOW
DOES DEVELOP THEN THE RAIN AND WIND ASPECT OF THE SYSTEM
INCREASES...DETAILS BELOW. STILL NEED TO WORK OUT MINOR DETAILS
WITH THIS PARTICULAR SYSTEM BUT WITH 3 TO 4 STANDARD DEVIATIONS
AWAY AND GENERAL MODEL AGREEMENT HAVE HIGH CONFIDENCE THIS SYSTEM
WILL IMPACT SOUTHERN NEW ENGLAND.

DETAILS...

SUNDAY NIGHT INTO TUESDAY...MODERATE CONFIDENCE.

HIGH PRESSURE AND UPPER LEVEL RIDGE WILL BEGIN TO MOVE OFFSHORE AS
DIGGING TROUGH BEGINS TO SET-UP OVER THE CENTRAL CONUS. APPEARS
ANOTHER MESOSCALE INVERTED TROUGH WILL SET UP ON MONDAY AND LAST
INTO EARLY TUESDAY MORNING. GUIDANCE SHOWS THAT RAIN/SNOW SHOWERS
WILL DEVELOP ALONG THE MASS EAST COASTLINE THANKS TO ONSHORE
EASTERLY FLOW. APPEARS THE COLUMN WILL SATURATE PER BUFKIT
SOUNDINGS AND SOUTHERLY FLOW ALOFT. BOTH THE NAM AND GFS SHOW QPF
MAKING IT ONSHORE DURING THIS TIME FRAME. HOWEVER THE EC IS
SLIGHTLY SLOWER AND KEEP THE BULK OF THE PRECIP JUST OFFSHORE. ADD
A CHANCE OF POPS DUE TO THE NAM/GFS MODEL CONTINUITY.

BY LATE MONDAY NIGHT INTO TUESDAY A SOUTHERN BRANCH STORM SYSTEM
FORMS ALONG THE SE COAST AND TAKES A TRACK OFF THE MID ATLANTIC
COAST. THIS SYSTEM GETS CAUGHT UP WITH THE OVERALL LARGE SCALE
AMPLIFICATION OF THE UPPER AIR PATTERN. THERE IS DECENT WARM
ADVECTION WITH COLD AIR DAMMING ACROSS THE INTERIOR. BIGGEST
QUESTION WILL BE IS THERE ENOUGH MOISTURE FOR PRECIP DURING THIS
TIME FRAME. IF PRECIP OVERRUNS THEN COULD SEE FREEZING RAIN/DRIZZLE
ACROSS THE INTERIOR LATE MONDAY INTO TUESDAY MORNING. DURING THE DAY
ON TUESDAY...GOOD AMOUNT OF WARM AIR WILL PUSH SURFACE TEMPS ABOVE
FREEZING ALLOWING FOR ANY PRECIP TO BE MORE OF THE LIQUID VARIETY
AHEAD OF THE CHRISTMAS EVE STORM. HOWEVER GUIDANCE IS ALWAYS TOO
FAST IN SCOURING TEMPS OUT ESP ACROSS THE CT VALLEY SO WE WILL NEED
TO MONITOR THIS CLOSELY...ESP DUE TO LIGHT WINDS AND THE HIGH IN
EASTERN CANADA.

WE COULD ALSO SEE SOME MINOR COASTAL FLOODING CONCERNS ON TUESDAY. SEE
BELOW FOR MORE DETAILS.

WEDNESDAY INTO THURSDAY...HIGH CONFIDENCE IN SYSTEM LOW CONFIDENCE
ON DETAILS.

STRONG ANOMALOUS SYSTEM WILL STRENGTHEN OVER THE GREAT
LAKES...DEVELOPING A POTENTIAL SECONDARY SURFACE LOW JUST WEST OF
SOUTHERN NEW ENGLAND. STILL A LOT OF DETAILS TO WORK OUT AS THIS
SYSTEM IS STILL 5 DAYS AWAY...HOWEVER ENSEMBLES CONTINUE TO SHOW
STRONG AGREEMENT SO HAVE INCREASING CONFIDENCE THAT A POTENT STORM
WILL OCCUR. LATEST 00Z GUIDANCE SHOWS THAT MOST PRECIP WILL BE
LIQUID WITH A DEEP SUBTROPICAL CONNECTION BACK ACROSS THE GULF OF
MEXICO...PW ANOMALIES FORECAST TO RISE BETWEEN +3 TO +4. CURRENT
PWATS ARE PROGGED ABOVE 1.6 INCHES SO HAVE CONTINUED THE CATEGORICAL
POPS. TEMPERATURES WILL BE WELL ABOVE AVERAGE...IN FACT WE MAY BE
CLOSE AT BREAKING RECORD HIGH TEMPS IF TEMPS WARM TO 60F OR ABOVE ON
CHRISTMAS EVE.  AS THE SYSTEM WRAPS UP INTO CANADA...COLD AIR
ADVECTION SHOULD CIRCULATE AROUND AND BEGIN A TRANSITION FROM
SOUTHWEST TO NORTHEAST IN TURNING P-TYPE TO SNOW. HOWEVER LATEST
GUIDANCE DOES SHOW A QUICK MOVING DRY SLOT SO SNOWFALL WILL STRUGGLE
DUE TO LACK OF MOISTURE.

THIS SYSTEM IS QUITE POTENT SO WE WILL NEED TO WATCH FOR POTENTIAL
HAZARDS. CURRENTLY THINK THAT WE COULD POSSIBLE URBAN FLOODING
ISSUES AS MODELS PROGGED WELL OVER 1.5 INCHES OF QPF. LATEST EC EVEN
SHOWS 2.5 INCHES OF QPF IS POSSIBLE. THE GEFS SHOW A MOISTURE FLUX
AT 850 MB BEING 4 TO 5 STANDARD DEVIATIONS AWAY...AND WITH THE
TROPICAL CONNECTION AND STRONG SOUTHERLY FLOW COULD SEE HIGHER
AMOUNTS DUE TO TOPOGRAPHY ENHANCEMENTS. RAIN FALL RECORDS MAY FALL
IF EVERYTHING FALLS INTO PLACE.

ALSO BELIEVE THAT WE MAY SEE SOME WIND ISSUES WITH THIS SYSTEM.
GUIDANCE RIGHT NOW IS SHOWING A 45 TO 55 KT JET AT 925 MB...HOWEVER
IT WILL BE HARD TO BREAK THE INVERSION WITH THE SOUTHERLY FLOW.
RIGHT NOW BELIEVE THAT WIND ADVISORIES MAY BE NEEDED BUT IF THIS
SYSTEM STRENGTHEN EVEN MORE SO A STRONGER JET IS POSSIBLE.

CONTINUED THE MENTIONED OF ISOLATED THUNDER IN THE FORECAST PER PREV
FORECASTER SUGGESTION. BELIEVE IT COULD BE POSSIBLE AS SOUTHERN NEW
ENGLAND WILL BE IN THE WARM SECTOR...WITH THE ANOMALOUS JET AND
SHOWALTERS CLOSE TO ZERO.

FRIDAY...LOW CONFIDENCE.

ONCE UPPER LEVEL LOW MOVES INTO SOUTHERN CANADA...EXPECT A RATHER
FAST UPPER W FLOW IN PLACE. MAY SEE LEFTOVER SNOW SHOWERS BUT TEMPS
WILL FALL BACK CLOSE TO SEASONAL NORMS.

&&

.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 SUNDAY/...

THROUGH 00Z...MODERATE CONFIDENCE. MVFR CIGS WILL CONTINUE TO
OVERSPREAD EASTERN NEW ENGLAND AND EVENTUALLY OVERSPREAD THE INTERIOR
THIS AFTERNOON. SCATTERED SHOWERS ACROSS PORTIONS OF EASTERN
MASSACHUSETTS THIS AFTERNOON. MAINLY SNOW SHOWERS TO THE NORTH AND
WEST OF CAPE COD CANAL...RAIN SHOWERS SOUTH AND EAST. LOCALIZED
IFR CONDITIONS POSSIBLE JUST INLAND FROM THE SOUTHEAST NEW ENGLAND
COAST...WHERE SNOW IS FALLING.

TONIGHT AND SUNDAY...MODERATE CONFIDENCE.  MVFR CONDITIONS DOMINATE
IN LOWER CLOUDS AND SCATTERED SHOWERS. LOCALIZED IFR CONDITIONS
POSSIBLE WITH THE BEST CHANCE IN SNOW SHOWERS. PRECIPITATION
AFFECTS MAINLY EASTERN NEW ENGLAND BUT STILL SOME SCATTERED
ACTIVITY ACROSS WESTERN NEW ENGLAND. MAINLY SNOW SHOWERS TO THE
NORTH AND WEST OF CAPE COD CANAL...RAIN SHOWERS SOUTH AND EAST.

KBOS TERMINAL...MODERATE CONFIDENCE IN TAF. FLURRIES AND SNOW
SHOWERS MAY AFFECT THE TERMINAL BY 21Z.

KBDL TERMINAL...MODERATE CONFIDENCE IN TAF.

OUTLOOK...SUNDAY NIGHT THROUGH WEDNESDAY...

MONDAY INTO TUESDAY...MODERATE CONFIDENCE. EXPECT MOSTLY
VFR...ISOLATED MVFR ALONG THE MASS EAST COASTLINE IN RAIN/SNOW
SHOWERS.

TUESDAY NIGHT INTO WEDNESDAY...MODERATE CONFIDENCE. CONDITIONS WILL
BE DETERIORATING AS HEAVY DOWNPOURS...ISO THUNDER AND GUSTY SOUTHERLY
WINDS MOVE INTO THE REGION BY WEDNESDAY. COULD SEE MVFR TO IFR
CONDITIONS IN CIGS AND VSBYS.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

HIGH CONFIDENCE. HIGH PRESSURE ACROSS QUEBEC WILL RESULT IN
PERSISTENT NORTHEAST WINDS ACROSS THE WATERS THROUGH THE WEEKEND.
WIND GUSTS UP TO 20 KNOTS WITH SEAS BETWEEN 2 AND 4 FEET ARE
EXPECTED FOR MOST WATERS...SO NO HEADLINES PLANNED.

THERE IS A LOW PROBABILITY THAT A BRIEF SURGE OF NORTHEAST WIND
GUSTS NEAR 25 KNOTS WITH MARGINAL 5 FOOT SEAS COULD AFFECT OUR
NORTHERN WATERS LATE TONIGHT INTO SUN MORNING...BUT NOT CONFIDENT
ENOUGH TO ISSUE ANY HEADLINES AT THIS POINT.

OUTLOOK...SUNDAY NIGHT INTO WEDNESDAY...MODERATE TO HIGH
CONFIDENCE.

SUNDAY INTO MONDAY. CONTINUOUS NORTHEAST FLOW WILL KEEP SEAS CHOPPY.
LINGERING NORTHEAST SWELL MAY BUMP SEAS ABOVE 5FT ESP ACROSS THE
NORTHEASTERN WATERS. SCA MAY BE NEEDED...BUT LOWER CONFIDENCE.

TUESDAY INTO WEDNESDAY...NE WINDS WILL INCREASE...GUSTING TO 30 KT
TUE THEN SHIFT TO SE GUSTING TO 30-35 KT WED...HIGHEST ON THE OUTER
WATERS. SEAS BUILD UP TO 7-11 FT BY WED. GALES WILL BE NEEDED.

&&

.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES WILL OCCUR TUESDAY THROUGH THURSDAY. BREAKING
IT DOWN...ON TUESDAY HIGH TIDE AT BOSTON WILL BE 11.6 FT. THERE WILL
BE ONSHORE FLOW DURING THIS HIGH TIDE ALLOWING FOR MINOR SPLASHOVER.
IF WIND GUSTS INCREASE THEN COULD POSSIBLE SEE MINOR COASTAL
FLOODING.

ON WEDNESDAY...WINDS WILL SWITCH TO A MORE SOUTHEASTERLY FLOW DURING
THE DAY AND INCREASE QUICKLY FROM APPROACHING SYSTEM AND DESCENT
PRESSURE FALLS. WEDNESDAY AFTERNOON HIGH TIDE IN BOSTON IS 11.7 FT
AND WITH ANY STRENGTH ON THE EASTERLY WIND FLOW WILL PUSH THE TIDE
OVER. RIGHT NOW BELIEVE MINOR COASTAL FLOODING IS POSSIBLE ALONG THE
EAST COASTLINE. HOWEVER WEDNESDAY EVENING...THE WIND GOES IN A MORE
SOUTHERLY DIRECTION AND HIGH TIDE IN PROVIDENCE WILL BE 5.2 FT. 925
MB LLJ STRENGTHENS TO 50-60 KTS WHICH COULD PUSH A DESCENT SURGE UP
ALONG THE SOUTH COAST DURING THE TIME OF HIGH TIDE. THINKING THAT
MINOR COASTAL FLOODING COULD OCCUR BUT CANNOT RULE OUT MODERATE
ALONG THE SOUTH COAST...ESP IF LLJ STRENGTHENS EVEN MORE.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...DUNTEN/RLG
NEAR TERM...RLG
SHORT TERM...RLG
LONG TERM...DUNTEN
AVIATION...DUNTEN/RLG
MARINE...DUNTEN/RLG
TIDES/COASTAL FLOODING...





000
FXUS61 KBOX 202026
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
326 PM EST SAT DEC 20 2014

.SYNOPSIS...
SCATTERED SNOW/RAIN SHOWERS WILL GRADUALLY OVERSPREAD THE REGION
FROM EAST TO WEST THIS AFTERNOON THROUGH SUN. WEAK LOW PRESSURE
WILL PASS SOUTH OF NEW ENGLAND BRINGING ANOTHER PERIOD OF PRECIP
MON NIGHT AND TUE. A MUCH STRONGER STORM PASSING WEST OF NEW
ENGLAND WILL BRING HEAVY RAINFALL...GUSTY WINDS AND COASTAL
FLOODING CONCERNS TO THE REGION WED INTO WED EVENING. DRY BUT VERY
WINDY CONDITIONS FOLLOW FOR CHRISTMAS DAY INTO FRI.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AN INVERTED TROUGH WILL DEVELOP THIS EVENING IN RESPONSE TO A
SHORTWAVE MOVING ACROSS SOUTHERN NEW ENGLAND.  THIS WILL PROVIDE A
FOCUS FOR RAIN/SNOW SHOWERS ACROSS MUCH OF EASTERN MASSACHUSETTS
BEGINNING THIS AFTERNOON AND CONTINUING THROUGH TONIGHT.  WHILE SNOW
SHOWERS MAY REACH INTO WESTERN NEW ENGLAND TONIGHT...A COASTAL FRONT
WILL DEVELOP...AIDING IN FOCUSING SHOWERS ALONG THE EAST COAST OF
MASSACHUSETTS.

SNOW SHOWERS WILL BECOME MORE WIDESPREAD TONIGHT AS THE LOW LEVELS
MOISTEN UP A BIT MORE. LOOKS LIKE IT WILL LIKELY BE WARM ENOUGH
ACROSS THE CAPE AND SOUTHEASTERN PLYMOUTH COUNTY FOR SHOWERS TO BE
RAIN RATHER THAN SNOW.

OVERALL...EXPECTING 1-2 INCHES OF SNOW AT MOST ACROSS EASTERN
MASSACHUSETTS AND RHODE ISLAND.  THERE ARE SEVERAL POTENTIAL PLACES
WHERE LOCALIZED SLIGHTLY HIGHER AMOUNTS /POSSIBLY UP TO 2-4 INCHES/
ARE POSSIBLE.  LOOKING AT THE HIGH RES MODELS...EITHER ACROSS ESSEX
COUNTY AND CAPE ANN...EASTERN NORFOLK COUNTY INTO NORTHERN PLYMOUTH
COUNTY...OR BOTH. THEN THE HIGHER TERRAIN OF WORCESTER COUNTY AND
PROVIDENCE COUNTY MAY SEE SLIGHTLY HIGHER AMOUNTS GIVEN THE UPSLOPE
COMPONENT OF THE WINDS.

SOME OF THE HIGH RES MODELS HAVE A DECENT CLIP OF QPF INTO ESSEX
COUNTY...WHILE OTHERS HAVE NOTHING IN THE SAME AREA.  FOR NORFOLK
AND PLYMOUTH COUNTY...WE MAY SEE A BIT OF OCEAN ENHANCEMENT THAT
RAISES SNOW AMOUNTS IN THOSE AREAS.  DUE TO THE UNCERTAINTY AND THE
LOCALIZED NATURE OF THE POTENTIAL HIGHER AMOUNTS...AM OPTING NOT TO
ISSUE A WINTER WEATHER ADVISORY. INSTEAD...REISSUED THE SPECIAL
WEATHER STATEMENT FOR SNOW. ANYONE OUT AND ABOUT THIS EVENING IN
EASTERN MASSACHUSETTS WILL WANT TO USE CAUTION AS THERE MAY BE
SLIPPERY PATCHES.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
RAIN/SNOW SHOWERS WILL CONTINUE INTO THE MORNING HOURS...THEN TAPER
OFF AS INVERTED TROUGH PULLS AWAY FROM SOUTHERN NEW ENGLAND AND HIGH
PRESSURE STARTS TO BUILD IN.  MOST LIKELY AREAS FOR CONTINUING
SHOWERS WILL BE ALONG THE IMMEDIATE EAST COAST OF MASSACHUSETTS.

AS THE DAY GOES ON...EXPECT A SLOW DRYING TREND AS HIGH PRESSURE
BUILDS INTO THE REGION.  CLOUDS WILL STICK AROUND WITH TEMPS
GENERALLY IN THE 30S.

&&

.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
HIGHLIGHTS...

* INVERTED TROUGH WILL BRING RAIN/SNOW SHOWERS TO THE MASS EAST
  COASTLINE MONDAY INTO TUES MORNING.
* WEAK WAVE OF LOW PRESSURE MON NIGHT/TUESDAY COULD BRING WINTRY
  MIX TO INTERIOR
* ANOMALOUS SYSTEM ACROSS THE GREAT LAKES WILL BRING HEAVY
  RAIN...GUSTY WINDS AND COASTAL FLOODING CONCERNS AROUND CHRISTMAS
  EVE

OVERVIEW...

OVERALL 00Z GUIDANCE IS IN AGREEMENT SYNOPTICALLY WITH ISSUES ON
TIMING AND SMALLER SCALE FEATURES. IT REMAINS EVIDENT THAT AN
AMPLIFIED MID-UPPER LEVEL TROUGH AND PCPN FOCUSING LEAD SURFACE
LOW/FRONTAL SYSTEM WILL STEADILY PROGRESS TO THE EAST-CENTRAL U.S.
TUE AS EMBEDDED IMPULSES DIG TO THE LEE OF AN AMPLIFIED ERN
PACIFIC/WEST COAST RIDGE ALOFT. THE SUPPORTING AND INCREASINGLY
NEGATIVE-TILT TROUGH ALOFT WORKS OVER THE ERN US AND OUT THROUGH THE
NERN STATES INTO DAYS 4/5 WED/THU.  MODELS/ENSEMBLES HAVE BEEN
FAIRLY CONSISTENT ON THIS AMPLIFIED PATTERN AND THE MOST RECENT
GEFS/ECMWF ENSEMBLE GUIDANCE SHOW GOOD CORRELATION TO NEXT THURSDAY.

HIGH PRESSURE AND UPPER LEVEL RIDGE OVER THE REGION WILL BEGIN TO
EXIT BY MONDAY. AT THE SURFACE APPEARS ANOTHER INVERTED
TROUGH/ONSHORE FLOW WILL YIELD TO PRECIP ALONG THE MASS COASTLINE ON
MONDAY. ASIDE FROM THIS QUICK MESOSCALE EVENT THE MAIN FOCUS IS ON
THE LONGWAVE DIGGING TROUGH OVER THE CENTRAL CONUS WHICH WILL PUSH A
FEW SHORTWAVES THROUGH THE FLOW. FIRST ONE DEVELOPS A WEAK WAVE
MOVING TOWARDS THE REGION LATE MONDAY INTO TUESDAY. THERE IS STILL
SOME UNCERTAINTY WITH THE LOCATION/STRENGTH OF THIS SYSTEM BUT
APPEARS THAT THERE IS THE POSSIBILITY OF A SNOW/WINTRY MIX IN THE
INTERIOR. AS THIS SYSTEM DEPARTS AN ANOMALOUS LOW OVER THE GREAT
LAKES WILL DEVELOP A SECONDARY LOW JUST WEST OF SOUTHERN NEW ENGLAND
PER ENSEMBLE GUIDANCE. STILL A SOME SPREAD BUT IF THIS DOUBLE LOW
DOES DEVELOP THEN THE RAIN AND WIND ASPECT OF THE SYSTEM
INCREASES...DETAILS BELOW. STILL NEED TO WORK OUT MINOR DETAILS
WITH THIS PARTICULAR SYSTEM BUT WITH 3 TO 4 STANDARD DEVIATIONS
AWAY AND GENERAL MODEL AGREEMENT HAVE HIGH CONFIDENCE THIS SYSTEM
WILL IMPACT SOUTHERN NEW ENGLAND.

DETAILS...

SUNDAY NIGHT INTO TUESDAY...MODERATE CONFIDENCE.

HIGH PRESSURE AND UPPER LEVEL RIDGE WILL BEGIN TO MOVE OFFSHORE AS
DIGGING TROUGH BEGINS TO SET-UP OVER THE CENTRAL CONUS. APPEARS
ANOTHER MESOSCALE INVERTED TROUGH WILL SET UP ON MONDAY AND LAST
INTO EARLY TUESDAY MORNING. GUIDANCE SHOWS THAT RAIN/SNOW SHOWERS
WILL DEVELOP ALONG THE MASS EAST COASTLINE THANKS TO ONSHORE
EASTERLY FLOW. APPEARS THE COLUMN WILL SATURATE PER BUFKIT
SOUNDINGS AND SOUTHERLY FLOW ALOFT. BOTH THE NAM AND GFS SHOW QPF
MAKING IT ONSHORE DURING THIS TIME FRAME. HOWEVER THE EC IS
SLIGHTLY SLOWER AND KEEP THE BULK OF THE PRECIP JUST OFFSHORE. ADD
A CHANCE OF POPS DUE TO THE NAM/GFS MODEL CONTINUITY.

BY LATE MONDAY NIGHT INTO TUESDAY A SOUTHERN BRANCH STORM SYSTEM
FORMS ALONG THE SE COAST AND TAKES A TRACK OFF THE MID ATLANTIC
COAST. THIS SYSTEM GETS CAUGHT UP WITH THE OVERALL LARGE SCALE
AMPLIFICATION OF THE UPPER AIR PATTERN. THERE IS DECENT WARM
ADVECTION WITH COLD AIR DAMMING ACROSS THE INTERIOR. BIGGEST
QUESTION WILL BE IS THERE ENOUGH MOISTURE FOR PRECIP DURING THIS
TIME FRAME. IF PRECIP OVERRUNS THEN COULD SEE FREEZING RAIN/DRIZZLE
ACROSS THE INTERIOR LATE MONDAY INTO TUESDAY MORNING. DURING THE DAY
ON TUESDAY...GOOD AMOUNT OF WARM AIR WILL PUSH SURFACE TEMPS ABOVE
FREEZING ALLOWING FOR ANY PRECIP TO BE MORE OF THE LIQUID VARIETY
AHEAD OF THE CHRISTMAS EVE STORM. HOWEVER GUIDANCE IS ALWAYS TOO
FAST IN SCOURING TEMPS OUT ESP ACROSS THE CT VALLEY SO WE WILL NEED
TO MONITOR THIS CLOSELY...ESP DUE TO LIGHT WINDS AND THE HIGH IN
EASTERN CANADA.

WE COULD ALSO SEE SOME MINOR COASTAL FLOODING CONCERNS ON TUESDAY. SEE
BELOW FOR MORE DETAILS.

WEDNESDAY INTO THURSDAY...HIGH CONFIDENCE IN SYSTEM LOW CONFIDENCE
ON DETAILS.

STRONG ANOMALOUS SYSTEM WILL STRENGTHEN OVER THE GREAT
LAKES...DEVELOPING A POTENTIAL SECONDARY SURFACE LOW JUST WEST OF
SOUTHERN NEW ENGLAND. STILL A LOT OF DETAILS TO WORK OUT AS THIS
SYSTEM IS STILL 5 DAYS AWAY...HOWEVER ENSEMBLES CONTINUE TO SHOW
STRONG AGREEMENT SO HAVE INCREASING CONFIDENCE THAT A POTENT STORM
WILL OCCUR. LATEST 00Z GUIDANCE SHOWS THAT MOST PRECIP WILL BE
LIQUID WITH A DEEP SUBTROPICAL CONNECTION BACK ACROSS THE GULF OF
MEXICO...PW ANOMALIES FORECAST TO RISE BETWEEN +3 TO +4. CURRENT
PWATS ARE PROGGED ABOVE 1.6 INCHES SO HAVE CONTINUED THE CATEGORICAL
POPS. TEMPERATURES WILL BE WELL ABOVE AVERAGE...IN FACT WE MAY BE
CLOSE AT BREAKING RECORD HIGH TEMPS IF TEMPS WARM TO 60F OR ABOVE ON
CHRISTMAS EVE.  AS THE SYSTEM WRAPS UP INTO CANADA...COLD AIR
ADVECTION SHOULD CIRCULATE AROUND AND BEGIN A TRANSITION FROM
SOUTHWEST TO NORTHEAST IN TURNING P-TYPE TO SNOW. HOWEVER LATEST
GUIDANCE DOES SHOW A QUICK MOVING DRY SLOT SO SNOWFALL WILL STRUGGLE
DUE TO LACK OF MOISTURE.

THIS SYSTEM IS QUITE POTENT SO WE WILL NEED TO WATCH FOR POTENTIAL
HAZARDS. CURRENTLY THINK THAT WE COULD POSSIBLE URBAN FLOODING
ISSUES AS MODELS PROGGED WELL OVER 1.5 INCHES OF QPF. LATEST EC EVEN
SHOWS 2.5 INCHES OF QPF IS POSSIBLE. THE GEFS SHOW A MOISTURE FLUX
AT 850 MB BEING 4 TO 5 STANDARD DEVIATIONS AWAY...AND WITH THE
TROPICAL CONNECTION AND STRONG SOUTHERLY FLOW COULD SEE HIGHER
AMOUNTS DUE TO TOPOGRAPHY ENHANCEMENTS. RAIN FALL RECORDS MAY FALL
IF EVERYTHING FALLS INTO PLACE.

ALSO BELIEVE THAT WE MAY SEE SOME WIND ISSUES WITH THIS SYSTEM.
GUIDANCE RIGHT NOW IS SHOWING A 45 TO 55 KT JET AT 925 MB...HOWEVER
IT WILL BE HARD TO BREAK THE INVERSION WITH THE SOUTHERLY FLOW.
RIGHT NOW BELIEVE THAT WIND ADVISORIES MAY BE NEEDED BUT IF THIS
SYSTEM STRENGTHEN EVEN MORE SO A STRONGER JET IS POSSIBLE.

CONTINUED THE MENTIONED OF ISOLATED THUNDER IN THE FORECAST PER PREV
FORECASTER SUGGESTION. BELIEVE IT COULD BE POSSIBLE AS SOUTHERN NEW
ENGLAND WILL BE IN THE WARM SECTOR...WITH THE ANOMALOUS JET AND
SHOWALTERS CLOSE TO ZERO.

FRIDAY...LOW CONFIDENCE.

ONCE UPPER LEVEL LOW MOVES INTO SOUTHERN CANADA...EXPECT A RATHER
FAST UPPER W FLOW IN PLACE. MAY SEE LEFTOVER SNOW SHOWERS BUT TEMPS
WILL FALL BACK CLOSE TO SEASONAL NORMS.

&&

.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 SUNDAY/...

THROUGH 00Z...MODERATE CONFIDENCE. MVFR CIGS WILL CONTINUE TO
OVERSPREAD EASTERN NEW ENGLAND AND EVENTUALLY OVERSPREAD THE INTERIOR
THIS AFTERNOON. SCATTERED SHOWERS ACROSS PORTIONS OF EASTERN
MASSACHUSETTS THIS AFTERNOON. MAINLY SNOW SHOWERS TO THE NORTH AND
WEST OF CAPE COD CANAL...RAIN SHOWERS SOUTH AND EAST. LOCALIZED
IFR CONDITIONS POSSIBLE JUST INLAND FROM THE SOUTHEAST NEW ENGLAND
COAST...WHERE SNOW IS FALLING.

TONIGHT AND SUNDAY...MODERATE CONFIDENCE.  MVFR CONDITIONS DOMINATE
IN LOWER CLOUDS AND SCATTERED SHOWERS. LOCALIZED IFR CONDITIONS
POSSIBLE WITH THE BEST CHANCE IN SNOW SHOWERS. PRECIPITATION
AFFECTS MAINLY EASTERN NEW ENGLAND BUT STILL SOME SCATTERED
ACTIVITY ACROSS WESTERN NEW ENGLAND. MAINLY SNOW SHOWERS TO THE
NORTH AND WEST OF CAPE COD CANAL...RAIN SHOWERS SOUTH AND EAST.

KBOS TERMINAL...MODERATE CONFIDENCE IN TAF. FLURRIES AND SNOW
SHOWERS MAY AFFECT THE TERMINAL BY 21Z.

KBDL TERMINAL...MODERATE CONFIDENCE IN TAF.

OUTLOOK...SUNDAY NIGHT THROUGH WEDNESDAY...

MONDAY INTO TUESDAY...MODERATE CONFIDENCE. EXPECT MOSTLY
VFR...ISOLATED MVFR ALONG THE MASS EAST COASTLINE IN RAIN/SNOW
SHOWERS.

TUESDAY NIGHT INTO WEDNESDAY...MODERATE CONFIDENCE. CONDITIONS WILL
BE DETERIORATING AS HEAVY DOWNPOURS...ISO THUNDER AND GUSTY SOUTHERLY
WINDS MOVE INTO THE REGION BY WEDNESDAY. COULD SEE MVFR TO IFR
CONDITIONS IN CIGS AND VSBYS.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

HIGH CONFIDENCE. HIGH PRESSURE ACROSS QUEBEC WILL RESULT IN
PERSISTENT NORTHEAST WINDS ACROSS THE WATERS THROUGH THE WEEKEND.
WIND GUSTS UP TO 20 KNOTS WITH SEAS BETWEEN 2 AND 4 FEET ARE
EXPECTED FOR MOST WATERS...SO NO HEADLINES PLANNED.

THERE IS A LOW PROBABILITY THAT A BRIEF SURGE OF NORTHEAST WIND
GUSTS NEAR 25 KNOTS WITH MARGINAL 5 FOOT SEAS COULD AFFECT OUR
NORTHERN WATERS LATE TONIGHT INTO SUN MORNING...BUT NOT CONFIDENT
ENOUGH TO ISSUE ANY HEADLINES AT THIS POINT.

OUTLOOK...SUNDAY NIGHT INTO WEDNESDAY...MODERATE TO HIGH
CONFIDENCE.

SUNDAY INTO MONDAY. CONTINUOUS NORTHEAST FLOW WILL KEEP SEAS CHOPPY.
LINGERING NORTHEAST SWELL MAY BUMP SEAS ABOVE 5FT ESP ACROSS THE
NORTHEASTERN WATERS. SCA MAY BE NEEDED...BUT LOWER CONFIDENCE.

TUESDAY INTO WEDNESDAY...NE WINDS WILL INCREASE...GUSTING TO 30 KT
TUE THEN SHIFT TO SE GUSTING TO 30-35 KT WED...HIGHEST ON THE OUTER
WATERS. SEAS BUILD UP TO 7-11 FT BY WED. GALES WILL BE NEEDED.

&&

.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES WILL OCCUR TUESDAY THROUGH THURSDAY. BREAKING
IT DOWN...ON TUESDAY HIGH TIDE AT BOSTON WILL BE 11.6 FT. THERE WILL
BE ONSHORE FLOW DURING THIS HIGH TIDE ALLOWING FOR MINOR SPLASHOVER.
IF WIND GUSTS INCREASE THEN COULD POSSIBLE SEE MINOR COASTAL
FLOODING.

ON WEDNESDAY...WINDS WILL SWITCH TO A MORE SOUTHEASTERLY FLOW DURING
THE DAY AND INCREASE QUICKLY FROM APPROACHING SYSTEM AND DESCENT
PRESSURE FALLS. WEDNESDAY AFTERNOON HIGH TIDE IN BOSTON IS 11.7 FT
AND WITH ANY STRENGTH ON THE EASTERLY WIND FLOW WILL PUSH THE TIDE
OVER. RIGHT NOW BELIEVE MINOR COASTAL FLOODING IS POSSIBLE ALONG THE
EAST COASTLINE. HOWEVER WEDNESDAY EVENING...THE WIND GOES IN A MORE
SOUTHERLY DIRECTION AND HIGH TIDE IN PROVIDENCE WILL BE 5.2 FT. 925
MB LLJ STRENGTHENS TO 50-60 KTS WHICH COULD PUSH A DESCENT SURGE UP
ALONG THE SOUTH COAST DURING THE TIME OF HIGH TIDE. THINKING THAT
MINOR COASTAL FLOODING COULD OCCUR BUT CANNOT RULE OUT MODERATE
ALONG THE SOUTH COAST...ESP IF LLJ STRENGTHENS EVEN MORE.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...DUNTEN/RLG
NEAR TERM...RLG
SHORT TERM...RLG
LONG TERM...DUNTEN
AVIATION...DUNTEN/RLG
MARINE...DUNTEN/RLG
TIDES/COASTAL FLOODING...




000
FXUS61 KBOX 201746
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
1246 PM EST SAT DEC 20 2014

.SYNOPSIS...
SCATTERED SNOW/RAIN SHOWERS WILL GRADUALLY OVERSPREAD THE REGION
FROM EAST TO WEST THIS AFTERNOON THROUGH SUN. WEAK LOW PRESSURE
WILL PASS SOUTH OF NEW ENGLAND BRINGING ANOTHER PERIOD OF PRECIP
MON NIGHT AND TUE. A MUCH STRONGER STORM PASSING WEST OF NEW
ENGLAND WILL BRING HEAVY RAINFALL...GUSTY WINDS AND COASTAL
FLOODING CONCERNS TO THE REGION WED INTO WED EVENING. DRY BUT VERY
WINDY CONDITIONS FOLLOW FOR CHRISTMAS DAY INTO FRI.

&&

.NEAR TERM /THROUGH TONIGHT/...
1245 PM UPDATE...SNOW SHOWERS CONTINUE TO AFFECT PORTIONS OF
EASTERN MASSACHUSETTS THIS AFTERNOON. THEY ARE STRUGGLING TO MOVE
WESTWARD OF CAPE ANN AND EASTERN NORFOLK COUNTY DUE TO MUCH DRIER
AIR. EVENTUALLY THE SHOWERS WILL OVERCOME THE DRIER AIR BUT EXPECT
THIS TO TAKE ANOTHER COUPLE OF HOURS...DEPENDING ON HOW QUICKLY
THE WINDS TURN TO THE NORTHEAST.

PREVIOUS DISCUSSION FOLLOWS...

INTERESTING MESOSCALE SETUP AS AN INVERTED TROUGH COMBINES WITH SOME
OCEAN ENHANCEMENT.  APPROACHING UPPER LEVEL SHORTWAVE WILL ALLOW FOR
EASTERLY FLOW JUST OFF THE GROUND.  THIS COMBINED WITH NORTHEAST
SURFACE WINDS WILL ALLOW LOW LEVEL OF THE ATMOSPHERE TO MOISTEN.
SOUNDINGS ACROSS EASTERN NEW ENGLAND BECOME SATURATED ALL THE WAY UP
TO THE -9C LAYER JUST ABOVE 850 MB.  THIS IS FAVORABLE FOR SOME
DECENT SNOW GROWTH...ITS JUST LOWER IN THE ATMOSPHERE THAN WE
TYPICALLY SEE WITH MORE SYNOPTIC SNOW EVENTS.  WHILE THIS IS NOT A
TRUE OCEAN EFFECT EVENT...DELTA T VALUES FROM THE MIXED LAYER TO THE
OCEAN ARE AROUND 15C.  THEREFORE...EXPECT SOME OCEAN ENHANCEMENT.

TIMING:

WHILE FLURRIES/LIGHT SNOW SHOWERS MAY OCCUR ACROSS FAR SOUTHEAST NEW
ENGLAND THIS MORNING.  THE MORE SUBSTANTIAL  PRECIPITATION SHOULD
OVERSPREAD PLYMOUTH COUNTY AS WELL AS THE CAPE AND ISLANDS THIS
AFTERNOON.  GIVEN EASTERLY FLOW JUST OFF THE GROUND...EXPECT SNOW
SHOWERS TO OVERSPREAD MOST OF EASTERN NEW ENGLAND THIS EVENING AS
LOW LEVELS MOISTEN.  IN FACT...SHOULD SEE AT LEAST SOME SCATTERED
SNOW SHOWERS AFFECT EVEN OUR FAR WESTERN ZONES.

PTYPE:

MAINLY SNOW FOR ALL BUT PORTIONS OF COASTAL PLYMOUTH COUNTY AND ONTO
THE CAPE/ISLANDS.  A SUBTLE COASTAL FRONT LOOKS TO SETUP ACROSS
SOUTHEAST COASTAL PLYMOUTH COUNTY.  PTYPE WILL BE SNOW TO THE
NORTHWEST OF THIS REGION...BUT ENOUGH MILD AIR SHOULD COME IN OFF
THE OCEAN FOR A CHANGE TO RAIN SHOWERS SOUTHEAST OF THIS REGION.
NOT EXPECTING THE POSITION OF THIS SUBTLE BOUNDARY TO CHANGE MUCH
THROUGH SUNDAY MORNING.

SNOW ACCUMULATIONS:

WE ARE GENERALLY LOOKING AT A COATING TO 2 INCHES OF SNOW ACROSS
MOST OF THE REGION.  THE MAIN FOCUS FOR 1 TO 2 INCHES WILL BE ACROSS
PORTIONS OF SOUTHEAST MA...AWAY FROM THE SOUTHEAST PLYMOUTH COUNTY
COAST.  ALSO...THE WORCESTER HILLS INTO NORTHWEST RHODE ISLAND MIGHT
BE ANOTHER AREA AS A RESULT OF THE SUBTLE UPSLOPE COMPONENT TO THE
WIND.  YOU CAN ACTUALLY SEE THAT IN SOME OF THE HIGH RESOLUTION
MODEL GUIDANCE.

THERE IS ONE AREA TO WATCH IN PARTICULAR...FROM NORTHWEST PLYMOUTH
COUNTY AND INTO NORFOLK COUNTY BASED ON MESOSCALE MODELS AND PATTERN
RECOGNITION.  WOULD NOT BE SURPRISED TO SEE VERY LOCALIZED 3 TO 4
INCH SNOW AMOUNTS...GIVEN SOME OCEAN ENHANCEMENT AND A LITTLE FOCUS
ON THE COASTAL FRONT.  WILL TRY TO HIGHLIGHT THIS AREA IN OUR
SNOWFALL AND PROBABILISTIC GRAPHICS.

&&

.SHORT TERM /SUNDAY/...
SCATTERED SNOW SHOWERS WILL CONTINUE DURING THE MORNING WITH
MOIST EASTERLY FLOW IN THE LOW LEVELS. AGAIN...PTYPE WILL BE SNOW
EXCEPT ACROSS SOUTHEAST PLYMOUTH COUNTY/CAPE AND ISLANDS WHERE
BOUNDARY LAYER WILL PROBABLY BE WARM ENOUGH FOR RAIN SHOWERS.
WHILE SOME LIGHT PRECIPITATION MAY LINGER INTO SUNDAY
AFTERNOON...EXPECT A DECREASE IN AREAL COVERAGE THROUGH THE
AFTERNOON AS LOW LEVEL LIFT WEAKENS. IT WILL REMAIN CLOUDY THOUGH
WITH TEMPS IN THE 30S.

&&

.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
HIGHLIGHTS...

* INVERTED TROUGH WILL BRING RAIN/SNOW SHOWERS TO THE MASS EAST
  COASTLINE MONDAY INTO TUES MORNING.
* WEAK WAVE OF LOW PRESSURE MON NIGHT/TUESDAY COULD BRING WINTRY
  MIX TO INTERIOR
* ANOMALOUS SYSTEM ACROSS THE GREAT LAKES WILL BRING HEAVY
  RAIN...GUSTY WINDS AND COASTAL FLOODING CONCERNS AROUND CHRISTMAS
  EVE

OVERVIEW...

OVERALL 00Z GUIDANCE IS IN AGREEMENT SYNOPTICALLY WITH ISSUES ON
TIMING AND SMALLER SCALE FEATURES. IT REMAINS EVIDENT THAT AN
AMPLIFIED MID-UPPER LEVEL TROUGH AND PCPN FOCUSING LEAD SURFACE
LOW/FRONTAL SYSTEM WILL STEADILY PROGRESS TO THE EAST-CENTRAL U.S.
TUE AS EMBEDDED IMPULSES DIG TO THE LEE OF AN AMPLIFIED ERN
PACIFIC/WEST COAST RIDGE ALOFT. THE SUPPORTING AND INCREASINGLY
NEGATIVE-TILT TROUGH ALOFT WORKS OVER THE ERN US AND OUT THROUGH THE
NERN STATES INTO DAYS 4/5 WED/THU.  MODELS/ENSEMBLES HAVE BEEN
FAIRLY CONSISTENT ON THIS AMPLIFIED PATTERN AND THE MOST RECENT
GEFS/ECMWF ENSEMBLE GUIDANCE SHOW GOOD CORRELATION TO NEXT THURSDAY.

HIGH PRESSURE AND UPPER LEVEL RIDGE OVER THE REGION WILL BEGIN TO
EXIT BY MONDAY. AT THE SURFACE APPEARS ANOTHER INVERTED
TROUGH/ONSHORE FLOW WILL YIELD TO PRECIP ALONG THE MASS COASTLINE ON
MONDAY. ASIDE FROM THIS QUICK MESOSCALE EVENT THE MAIN FOCUS IS ON
THE LONGWAVE DIGGING TROUGH OVER THE CENTRAL CONUS WHICH WILL PUSH A
FEW SHORTWAVES THROUGH THE FLOW. FIRST ONE DEVELOPS A WEAK WAVE
MOVING TOWARDS THE REGION LATE MONDAY INTO TUESDAY. THERE IS STILL
SOME UNCERTAINTY WITH THE LOCATION/STRENGTH OF THIS SYSTEM BUT
APPEARS THAT THERE IS THE POSSIBILITY OF A SNOW/WINTRY MIX IN THE
INTERIOR. AS THIS SYSTEM DEPARTS AN ANOMALOUS LOW OVER THE GREAT
LAKES WILL DEVELOP A SECONDARY LOW JUST WEST OF SOUTHERN NEW ENGLAND
PER ENSEMBLE GUIDANCE. STILL A SOME SPREAD BUT IF THIS DOUBLE LOW
DOES DEVELOP THEN THE RAIN AND WIND ASPECT OF THE SYSTEM
INCREASES...DETAILS BELOW. STILL NEED TO WORK OUT MINOR DETAILS
WITH THIS PARTICULAR SYSTEM BUT WITH 3 TO 4 STANDARD DEVIATIONS
AWAY AND GENERAL MODEL AGREEMENT HAVE HIGH CONFIDENCE THIS SYSTEM
WILL IMPACT SOUTHERN NEW ENGLAND.

DETAILS...

SUNDAY NIGHT INTO TUESDAY...MODERATE CONFIDENCE.

HIGH PRESSURE AND UPPER LEVEL RIDGE WILL BEGIN TO MOVE OFFSHORE AS
DIGGING TROUGH BEGINS TO SET-UP OVER THE CENTRAL CONUS. APPEARS
ANOTHER MESO-SCALE INVERTED TROUGH WILL SET UP ON MONDAY AND LAST
INTO EARLY TUESDAY MORNING. GUIDANCE SHOWS THAT RAIN/SNOW SHOWERS
WILL DEVELOP ALONG THE MASS EAST COASTLINE THANKS TO ONSHORE
EASTERLY FLOW. APPEARS THE COLUMN WILL SATURATE PER BUFKIT SOUNDINGS
AND SOUTHERLY FLOW ALOFT. BOTH THE NAM AND GFS SHOW QPF MAKING IT
ONSHORE DURING THIS TIME FRAME. HOWEVER THE EC IS SLIGHTLY SLOWER
AND KEEP THE BULK OF THE PRECIP JUST OFFSHORE. ADD A CHANCE OF POPS
DUE TO THE NAM/GFS MODEL CONTINUITY.

BY LATE MONDAY NIGHT INTO TUESDAY A SOUTHERN BRANCH STORM SYSTEM
FORMS ALONG THE SE COAST AND TAKES A TRACK OFF THE MID ATLANTIC
COAST. THIS SYSTEM GETS CAUGHT UP WITH THE OVERALL LARGE SCALE
AMPLIFICATION OF THE UPPER AIR PATTERN. THERE IS DECENT WARM
ADVECTION WITH COLD AIR DAMMING ACROSS THE INTERIOR. BIGGEST
QUESTION WILL BE IS THERE ENOUGH MOISTURE FOR PRECIP DURING THIS
TIME FRAME. IF PRECIP OVERRUNS THEN COULD SEE FREEZING RAIN/DRIZZLE
ACROSS THE INTERIOR LATE MONDAY INTO TUESDAY MORNING. DURING THE DAY
ON TUESDAY...GOOD AMOUNT OF WARM AIR WILL PUSH SURFACE TEMPS ABOVE
FREEZING ALLOWING FOR ANY PRECIP TO BE MORE OF THE LIQUID VARIETY
AHEAD OF THE CHRISTMAS EVE STORM. HOWEVER GUIDANCE IS ALWAYS TOO
FAST IN SCOURING TEMPS OUT ESP ACROSS THE CT VALLEY SO WE WILL NEED
TO MONITOR THIS CLOSELY...ESP DUE TO LIGHT WINDS AND THE HIGH IN
EASTERN CANADA.

WE COULD ALSO SEE SOME MINOR COASTAL FLOODING CONCERNS ON TUESDAY. SEE
BELOW FOR MORE DETAILS.

WEDNESDAY INTO THURSDAY...HIGH CONFIDENCE IN SYSTEM LOW CONFIDENCE
ON DETAILS.

STRONG ANOMALOUS SYSTEM WILL STRENGTHEN OVER THE GREAT
LAKES...DEVELOPING A POTENTIAL SECONDARY SURFACE LOW JUST WEST OF
SOUTHERN NEW ENGLAND. STILL A LOT OF DETAILS TO WORK OUT AS THIS
SYSTEM IS STILL 5 DAYS AWAY...HOWEVER ENSEMBLES CONTINUE TO SHOW
STRONG AGREEMENT SO HAVE INCREASING CONFIDENCE THAT A POTENT STORM
WILL OCCUR. LATEST 00Z GUIDANCE SHOWS THAT MOST PRECIP WILL BE
LIQUID WITH A DEEP SUBTROPICAL CONNECTION BACK ACROSS THE GULF OF
MEXICO...PW ANOMALIES FORECAST TO RISE BETWEEN +3 TO +4. CURRENT
PWATS ARE PROGGED ABOVE 1.6 INCHES SO HAVE CONTINUED THE CATEGORICAL
POPS. TEMPERATURES WILL BE WELL ABOVE AVERAGE...IN FACT WE MAY BE
CLOSE AT BREAKING RECORD HIGH TEMPS IF TEMPS WARM TO 60F OR ABOVE ON
CHRISTMAS EVE.  AS THE SYSTEM WRAPS UP INTO CANADA...COLD AIR
ADVECTION SHOULD CIRCULATE AROUND AND BEGIN A TRANSITION FROM
SOUTHWEST TO NORTHEAST IN TURNING P-TYPE TO SNOW. HOWEVER LATEST
GUIDANCE DOES SHOW A QUICK MOVING DRY SLOT SO SNOWFALL WILL STRUGGLE
DUE TO LACK OF MOISTURE.

THIS SYSTEM IS QUITE POTENT SO WE WILL NEED TO WATCH FOR POTENTIAL
HAZARDS. CURRENTLY THINK THAT WE COULD POSSIBLE URBAN FLOODING
ISSUES AS MODELS PROGGED WELL OVER 1.5 INCHES OF QPF. LATEST EC EVEN
SHOWS 2.5 INCHES OF QPF IS POSSIBLE. THE GEFS SHOW A MOISTURE FLUX
AT 850 MB BEING 4 TO 5 STANDARD DEVIATIONS AWAY...AND WITH THE
TROPICAL CONNECTION AND STRONG SOUTHERLY FLOW COULD SEE HIGHER
AMOUNTS DUE TO TOPOGRAPHY ENHANCEMENTS. RAIN FALL RECORDS MAY FALL
IF EVERYTHING FALLS INTO PLACE.

ALSO BELIEVE THAT WE MAY SEE SOME WIND ISSUES WITH THIS SYSTEM.
GUIDANCE RIGHT NOW IS SHOWING A 45 TO 55 KT JET AT 925 MB...HOWEVER
IT WILL BE HARD TO BREAK THE INVERSION WITH THE SOUTHERLY FLOW.
RIGHT NOW BELIEVE THAT WIND ADVISORIES MAY BE NEEDED BUT IF THIS
SYSTEM STRENGTHEN EVEN MORE SO A STRONGER JET IS POSSIBLE.

CONTINUED THE MENTIONED OF ISOLATED THUNDER IN THE FORECAST PER PREV
FORECASTER SUGGESTION. BELIEVE IT COULD BE POSSIBLE AS SOUTHERN NEW
ENGLAND WILL BE IN THE WARM SECTOR...WITH THE ANOMALOUS JET AND
SHOWALTERS CLOSE TO ZERO.

FRIDAY...LOW CONFIDENCE.

ONCE UPPER LEVEL LOW MOVES INTO SOUTHERN CANADA...EXPECT A RATHER
FAST UPPER W FLOW IN PLACE. MAY SEE LEFTOVER SNOW SHOWERS BUT TEMPS
WILL FALL BACK CLOSE TO SEASONAL NORMS.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /THROUGH SUNDAY/...

THROUGH 00Z...MODERATE CONFIDENCE. MVFR CIGS WILL CONTINUE TO
OVERSPREAD EASTERN NEW ENGLAND AND EVENTUALLY OVERSPREAD THE INTERIOR
THIS AFTERNOON. SCATTERED SHOWERS ACROSS PORTIONS OF EASTERN
MASSACHUSETTS THIS AFTERNOON. MAINLY SNOW SHOWERS TO THE NORTH AND
WEST OF CAPE COD CANAL...RAIN SHOWERS SOUTH AND EAST. LOCALIZED
IFR CONDITIONS POSSIBLE JUST INLAND FROM THE SOUTHEAST NEW ENGLAND
COAST...WHERE SNOW IS FALLING.

TONIGHT AND SUNDAY...MODERATE CONFIDENCE.  MVFR CONDITIONS DOMINATE
IN LOWER CLOUDS AND SCATTERED SHOWERS. LOCALIZED IFR CONDITIONS
POSSIBLE WITH THE BEST CHANCE IN SNOW SHOWERS. PRECIPITATION
AFFECTS MAINLY EASTERN NEW ENGLAND BUT STILL SOME SCATTERED
ACTIVITY ACROSS WESTERN NEW ENGLAND. MAINLY SNOW SHOWERS TO THE
NORTH AND WEST OF CAPE COD CANAL...RAIN SHOWERS SOUTH AND EAST.

KBOS TERMINAL...MODERATE CONFIDENCE IN TAF. FLURRIES AND SNOW
SHOWERS MAY AFFECT THE TERMINAL BY 21Z.

KBDL TERMINAL...MODERATE CONFIDENCE IN TAF.

OUTLOOK...SUNDAY NIGHT THROUGH WEDNESDAY...

MONDAY INTO TUESDAY...MODERATE CONFIDENCE. EXPECT MOSTLY
VFR...ISOLATED MVFR ALONG THE MASS EAST COASTLINE IN RAIN/SNOW
SHOWERS.

TUESDAY NIGHT INTO WEDNESDAY...MODERATE CONFIDENCE. CONDITIONS WILL
BE DETERIORATING AS HEAVY DOWNPOURS...ISO THUNDER AND GUSTY SOUTHERLY
WINDS MOVE INTO THE REGION BY WEDNESDAY. COULD SEE MVFR TO IFR
CONDITIONS IN CIGS AND VSBYS.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /TODAY THROUGH SUNDAY/...HIGH CONFIDENCE.

HIGH PRESSURE ACROSS QUEBEC WILL RESULT IN PERSISTENT NORTHEAST
WINDS ACROSS THE WATERS THROUGH THE WEEKEND.  WIND GUSTS UP TO 20
KNOTS WITH SEAS BETWEEN 2 AND 4 FEET ARE EXPECTED FOR MOST
WATERS...SO NO HEADLINES PLANNED. THERE IS A LOW PROBABILITY THAT A
BRIEF SURGE OF NORTHEAST WIND GUSTS NEAR 25 KNOTS WITH MARGINAL 5
FOOT SEAS COULD AFFECT OUR NORTHERN WATERS LATE TONIGHT INTO SUN
MORNING...BUT NOT CONFIDENT ENOUGH TO ISSUE ANY HEADLINES AT THIS
POINT.

OUTLOOK...SUNDAY NIGHT INTO WEDNESDAY...MODERATE TO HIGH
CONFIDENCE.

SUNDAY INTO MONDAY. CONTINUOUS NORTHEAST FLOW WILL KEEP SEAS CHOPPY.
LINGERING NORTHEAST SWELL MAY BUMP SEAS ABOVE 5FT ESP ACROSS THE
NORTHEASTERN WATERS. SCA MAY BE NEEDED...BUT LOWER CONFIDENCE.

TUESDAY INTO WEDNESDAY...NE WINDS WILL INCREASE...GUSTING TO 30 KT
TUE THEN SHIFT TO SE GUSTING TO 30-35 KT WED...HIGHEST ON THE OUTER
WATERS. SEAS BUILD UP TO 7-11 FT BY WED. GALES WILL BE NEEDED.

&&

.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES WILL OCCUR TUESDAY THROUGH THURSDAY. BREAKING
IT DOWN...ON TUESDAY HIGH TIDE AT BOSTON WILL BE 11.6 FT. THERE WILL
BE ONSHORE FLOW DURING THIS HIGH TIDE ALLOWING FOR MINOR SPLASHOVER.
IF WIND GUSTS INCREASE THEN COULD POSSIBLE SEE MINOR COASTAL
FLOODING.

ON WEDNESDAY...WINDS WILL SWITCH TO A MORE SOUTHEASTERLY FLOW DURING
THE DAY AND INCREASE QUICKLY FROM APPROACHING SYSTEM AND DESCENT
PRESSURE FALLS. WEDNESDAY AFTERNOON HIGH TIDE IN BOSTON IS 11.7 FT
AND WITH ANY STRENGTH ON THE EASTERLY WIND FLOW WILL PUSH THE TIDE
OVER. RIGHT NOW BELIEVE MINOR COASTAL FLOODING IS POSSIBLE ALONG THE
EAST COASTLINE. HOWEVER WEDNESDAY EVENING...THE WIND GOES IN A MORE
SOUTHERLY DIRECTION AND HIGH TIDE IN PROVIDENCE WILL BE 5.2 FT. 925
MB LLJ STRENGTHENS TO 50-60 KTS WHICH COULD PUSH A DESCENT SURGE UP
ALONG THE SOUTH COAST DURING THE TIME OF HIGH TIDE. THINKING THAT
MINOR COASTAL FLOODING COULD OCCUR BUT CANNOT RULE OUT MODERATE
ALONG THE SOUTH COAST...ESP IF LLJ STRENGTHENS EVEN MORE.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...DUNTEN/RLG
NEAR TERM...FRANK/RLG
SHORT TERM...FRANK
LONG TERM...DUNTEN
AVIATION...DUNTEN/RLG
MARINE...FRANK/DUNTEN
TIDES/COASTAL FLOODING...





000
FXUS61 KBOX 201746
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
1246 PM EST SAT DEC 20 2014

.SYNOPSIS...
SCATTERED SNOW/RAIN SHOWERS WILL GRADUALLY OVERSPREAD THE REGION
FROM EAST TO WEST THIS AFTERNOON THROUGH SUN. WEAK LOW PRESSURE
WILL PASS SOUTH OF NEW ENGLAND BRINGING ANOTHER PERIOD OF PRECIP
MON NIGHT AND TUE. A MUCH STRONGER STORM PASSING WEST OF NEW
ENGLAND WILL BRING HEAVY RAINFALL...GUSTY WINDS AND COASTAL
FLOODING CONCERNS TO THE REGION WED INTO WED EVENING. DRY BUT VERY
WINDY CONDITIONS FOLLOW FOR CHRISTMAS DAY INTO FRI.

&&

.NEAR TERM /THROUGH TONIGHT/...
1245 PM UPDATE...SNOW SHOWERS CONTINUE TO AFFECT PORTIONS OF
EASTERN MASSACHUSETTS THIS AFTERNOON. THEY ARE STRUGGLING TO MOVE
WESTWARD OF CAPE ANN AND EASTERN NORFOLK COUNTY DUE TO MUCH DRIER
AIR. EVENTUALLY THE SHOWERS WILL OVERCOME THE DRIER AIR BUT EXPECT
THIS TO TAKE ANOTHER COUPLE OF HOURS...DEPENDING ON HOW QUICKLY
THE WINDS TURN TO THE NORTHEAST.

PREVIOUS DISCUSSION FOLLOWS...

INTERESTING MESOSCALE SETUP AS AN INVERTED TROUGH COMBINES WITH SOME
OCEAN ENHANCEMENT.  APPROACHING UPPER LEVEL SHORTWAVE WILL ALLOW FOR
EASTERLY FLOW JUST OFF THE GROUND.  THIS COMBINED WITH NORTHEAST
SURFACE WINDS WILL ALLOW LOW LEVEL OF THE ATMOSPHERE TO MOISTEN.
SOUNDINGS ACROSS EASTERN NEW ENGLAND BECOME SATURATED ALL THE WAY UP
TO THE -9C LAYER JUST ABOVE 850 MB.  THIS IS FAVORABLE FOR SOME
DECENT SNOW GROWTH...ITS JUST LOWER IN THE ATMOSPHERE THAN WE
TYPICALLY SEE WITH MORE SYNOPTIC SNOW EVENTS.  WHILE THIS IS NOT A
TRUE OCEAN EFFECT EVENT...DELTA T VALUES FROM THE MIXED LAYER TO THE
OCEAN ARE AROUND 15C.  THEREFORE...EXPECT SOME OCEAN ENHANCEMENT.

TIMING:

WHILE FLURRIES/LIGHT SNOW SHOWERS MAY OCCUR ACROSS FAR SOUTHEAST NEW
ENGLAND THIS MORNING.  THE MORE SUBSTANTIAL  PRECIPITATION SHOULD
OVERSPREAD PLYMOUTH COUNTY AS WELL AS THE CAPE AND ISLANDS THIS
AFTERNOON.  GIVEN EASTERLY FLOW JUST OFF THE GROUND...EXPECT SNOW
SHOWERS TO OVERSPREAD MOST OF EASTERN NEW ENGLAND THIS EVENING AS
LOW LEVELS MOISTEN.  IN FACT...SHOULD SEE AT LEAST SOME SCATTERED
SNOW SHOWERS AFFECT EVEN OUR FAR WESTERN ZONES.

PTYPE:

MAINLY SNOW FOR ALL BUT PORTIONS OF COASTAL PLYMOUTH COUNTY AND ONTO
THE CAPE/ISLANDS.  A SUBTLE COASTAL FRONT LOOKS TO SETUP ACROSS
SOUTHEAST COASTAL PLYMOUTH COUNTY.  PTYPE WILL BE SNOW TO THE
NORTHWEST OF THIS REGION...BUT ENOUGH MILD AIR SHOULD COME IN OFF
THE OCEAN FOR A CHANGE TO RAIN SHOWERS SOUTHEAST OF THIS REGION.
NOT EXPECTING THE POSITION OF THIS SUBTLE BOUNDARY TO CHANGE MUCH
THROUGH SUNDAY MORNING.

SNOW ACCUMULATIONS:

WE ARE GENERALLY LOOKING AT A COATING TO 2 INCHES OF SNOW ACROSS
MOST OF THE REGION.  THE MAIN FOCUS FOR 1 TO 2 INCHES WILL BE ACROSS
PORTIONS OF SOUTHEAST MA...AWAY FROM THE SOUTHEAST PLYMOUTH COUNTY
COAST.  ALSO...THE WORCESTER HILLS INTO NORTHWEST RHODE ISLAND MIGHT
BE ANOTHER AREA AS A RESULT OF THE SUBTLE UPSLOPE COMPONENT TO THE
WIND.  YOU CAN ACTUALLY SEE THAT IN SOME OF THE HIGH RESOLUTION
MODEL GUIDANCE.

THERE IS ONE AREA TO WATCH IN PARTICULAR...FROM NORTHWEST PLYMOUTH
COUNTY AND INTO NORFOLK COUNTY BASED ON MESOSCALE MODELS AND PATTERN
RECOGNITION.  WOULD NOT BE SURPRISED TO SEE VERY LOCALIZED 3 TO 4
INCH SNOW AMOUNTS...GIVEN SOME OCEAN ENHANCEMENT AND A LITTLE FOCUS
ON THE COASTAL FRONT.  WILL TRY TO HIGHLIGHT THIS AREA IN OUR
SNOWFALL AND PROBABILISTIC GRAPHICS.

&&

.SHORT TERM /SUNDAY/...
SCATTERED SNOW SHOWERS WILL CONTINUE DURING THE MORNING WITH
MOIST EASTERLY FLOW IN THE LOW LEVELS. AGAIN...PTYPE WILL BE SNOW
EXCEPT ACROSS SOUTHEAST PLYMOUTH COUNTY/CAPE AND ISLANDS WHERE
BOUNDARY LAYER WILL PROBABLY BE WARM ENOUGH FOR RAIN SHOWERS.
WHILE SOME LIGHT PRECIPITATION MAY LINGER INTO SUNDAY
AFTERNOON...EXPECT A DECREASE IN AREAL COVERAGE THROUGH THE
AFTERNOON AS LOW LEVEL LIFT WEAKENS. IT WILL REMAIN CLOUDY THOUGH
WITH TEMPS IN THE 30S.

&&

.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
HIGHLIGHTS...

* INVERTED TROUGH WILL BRING RAIN/SNOW SHOWERS TO THE MASS EAST
  COASTLINE MONDAY INTO TUES MORNING.
* WEAK WAVE OF LOW PRESSURE MON NIGHT/TUESDAY COULD BRING WINTRY
  MIX TO INTERIOR
* ANOMALOUS SYSTEM ACROSS THE GREAT LAKES WILL BRING HEAVY
  RAIN...GUSTY WINDS AND COASTAL FLOODING CONCERNS AROUND CHRISTMAS
  EVE

OVERVIEW...

OVERALL 00Z GUIDANCE IS IN AGREEMENT SYNOPTICALLY WITH ISSUES ON
TIMING AND SMALLER SCALE FEATURES. IT REMAINS EVIDENT THAT AN
AMPLIFIED MID-UPPER LEVEL TROUGH AND PCPN FOCUSING LEAD SURFACE
LOW/FRONTAL SYSTEM WILL STEADILY PROGRESS TO THE EAST-CENTRAL U.S.
TUE AS EMBEDDED IMPULSES DIG TO THE LEE OF AN AMPLIFIED ERN
PACIFIC/WEST COAST RIDGE ALOFT. THE SUPPORTING AND INCREASINGLY
NEGATIVE-TILT TROUGH ALOFT WORKS OVER THE ERN US AND OUT THROUGH THE
NERN STATES INTO DAYS 4/5 WED/THU.  MODELS/ENSEMBLES HAVE BEEN
FAIRLY CONSISTENT ON THIS AMPLIFIED PATTERN AND THE MOST RECENT
GEFS/ECMWF ENSEMBLE GUIDANCE SHOW GOOD CORRELATION TO NEXT THURSDAY.

HIGH PRESSURE AND UPPER LEVEL RIDGE OVER THE REGION WILL BEGIN TO
EXIT BY MONDAY. AT THE SURFACE APPEARS ANOTHER INVERTED
TROUGH/ONSHORE FLOW WILL YIELD TO PRECIP ALONG THE MASS COASTLINE ON
MONDAY. ASIDE FROM THIS QUICK MESOSCALE EVENT THE MAIN FOCUS IS ON
THE LONGWAVE DIGGING TROUGH OVER THE CENTRAL CONUS WHICH WILL PUSH A
FEW SHORTWAVES THROUGH THE FLOW. FIRST ONE DEVELOPS A WEAK WAVE
MOVING TOWARDS THE REGION LATE MONDAY INTO TUESDAY. THERE IS STILL
SOME UNCERTAINTY WITH THE LOCATION/STRENGTH OF THIS SYSTEM BUT
APPEARS THAT THERE IS THE POSSIBILITY OF A SNOW/WINTRY MIX IN THE
INTERIOR. AS THIS SYSTEM DEPARTS AN ANOMALOUS LOW OVER THE GREAT
LAKES WILL DEVELOP A SECONDARY LOW JUST WEST OF SOUTHERN NEW ENGLAND
PER ENSEMBLE GUIDANCE. STILL A SOME SPREAD BUT IF THIS DOUBLE LOW
DOES DEVELOP THEN THE RAIN AND WIND ASPECT OF THE SYSTEM
INCREASES...DETAILS BELOW. STILL NEED TO WORK OUT MINOR DETAILS
WITH THIS PARTICULAR SYSTEM BUT WITH 3 TO 4 STANDARD DEVIATIONS
AWAY AND GENERAL MODEL AGREEMENT HAVE HIGH CONFIDENCE THIS SYSTEM
WILL IMPACT SOUTHERN NEW ENGLAND.

DETAILS...

SUNDAY NIGHT INTO TUESDAY...MODERATE CONFIDENCE.

HIGH PRESSURE AND UPPER LEVEL RIDGE WILL BEGIN TO MOVE OFFSHORE AS
DIGGING TROUGH BEGINS TO SET-UP OVER THE CENTRAL CONUS. APPEARS
ANOTHER MESO-SCALE INVERTED TROUGH WILL SET UP ON MONDAY AND LAST
INTO EARLY TUESDAY MORNING. GUIDANCE SHOWS THAT RAIN/SNOW SHOWERS
WILL DEVELOP ALONG THE MASS EAST COASTLINE THANKS TO ONSHORE
EASTERLY FLOW. APPEARS THE COLUMN WILL SATURATE PER BUFKIT SOUNDINGS
AND SOUTHERLY FLOW ALOFT. BOTH THE NAM AND GFS SHOW QPF MAKING IT
ONSHORE DURING THIS TIME FRAME. HOWEVER THE EC IS SLIGHTLY SLOWER
AND KEEP THE BULK OF THE PRECIP JUST OFFSHORE. ADD A CHANCE OF POPS
DUE TO THE NAM/GFS MODEL CONTINUITY.

BY LATE MONDAY NIGHT INTO TUESDAY A SOUTHERN BRANCH STORM SYSTEM
FORMS ALONG THE SE COAST AND TAKES A TRACK OFF THE MID ATLANTIC
COAST. THIS SYSTEM GETS CAUGHT UP WITH THE OVERALL LARGE SCALE
AMPLIFICATION OF THE UPPER AIR PATTERN. THERE IS DECENT WARM
ADVECTION WITH COLD AIR DAMMING ACROSS THE INTERIOR. BIGGEST
QUESTION WILL BE IS THERE ENOUGH MOISTURE FOR PRECIP DURING THIS
TIME FRAME. IF PRECIP OVERRUNS THEN COULD SEE FREEZING RAIN/DRIZZLE
ACROSS THE INTERIOR LATE MONDAY INTO TUESDAY MORNING. DURING THE DAY
ON TUESDAY...GOOD AMOUNT OF WARM AIR WILL PUSH SURFACE TEMPS ABOVE
FREEZING ALLOWING FOR ANY PRECIP TO BE MORE OF THE LIQUID VARIETY
AHEAD OF THE CHRISTMAS EVE STORM. HOWEVER GUIDANCE IS ALWAYS TOO
FAST IN SCOURING TEMPS OUT ESP ACROSS THE CT VALLEY SO WE WILL NEED
TO MONITOR THIS CLOSELY...ESP DUE TO LIGHT WINDS AND THE HIGH IN
EASTERN CANADA.

WE COULD ALSO SEE SOME MINOR COASTAL FLOODING CONCERNS ON TUESDAY. SEE
BELOW FOR MORE DETAILS.

WEDNESDAY INTO THURSDAY...HIGH CONFIDENCE IN SYSTEM LOW CONFIDENCE
ON DETAILS.

STRONG ANOMALOUS SYSTEM WILL STRENGTHEN OVER THE GREAT
LAKES...DEVELOPING A POTENTIAL SECONDARY SURFACE LOW JUST WEST OF
SOUTHERN NEW ENGLAND. STILL A LOT OF DETAILS TO WORK OUT AS THIS
SYSTEM IS STILL 5 DAYS AWAY...HOWEVER ENSEMBLES CONTINUE TO SHOW
STRONG AGREEMENT SO HAVE INCREASING CONFIDENCE THAT A POTENT STORM
WILL OCCUR. LATEST 00Z GUIDANCE SHOWS THAT MOST PRECIP WILL BE
LIQUID WITH A DEEP SUBTROPICAL CONNECTION BACK ACROSS THE GULF OF
MEXICO...PW ANOMALIES FORECAST TO RISE BETWEEN +3 TO +4. CURRENT
PWATS ARE PROGGED ABOVE 1.6 INCHES SO HAVE CONTINUED THE CATEGORICAL
POPS. TEMPERATURES WILL BE WELL ABOVE AVERAGE...IN FACT WE MAY BE
CLOSE AT BREAKING RECORD HIGH TEMPS IF TEMPS WARM TO 60F OR ABOVE ON
CHRISTMAS EVE.  AS THE SYSTEM WRAPS UP INTO CANADA...COLD AIR
ADVECTION SHOULD CIRCULATE AROUND AND BEGIN A TRANSITION FROM
SOUTHWEST TO NORTHEAST IN TURNING P-TYPE TO SNOW. HOWEVER LATEST
GUIDANCE DOES SHOW A QUICK MOVING DRY SLOT SO SNOWFALL WILL STRUGGLE
DUE TO LACK OF MOISTURE.

THIS SYSTEM IS QUITE POTENT SO WE WILL NEED TO WATCH FOR POTENTIAL
HAZARDS. CURRENTLY THINK THAT WE COULD POSSIBLE URBAN FLOODING
ISSUES AS MODELS PROGGED WELL OVER 1.5 INCHES OF QPF. LATEST EC EVEN
SHOWS 2.5 INCHES OF QPF IS POSSIBLE. THE GEFS SHOW A MOISTURE FLUX
AT 850 MB BEING 4 TO 5 STANDARD DEVIATIONS AWAY...AND WITH THE
TROPICAL CONNECTION AND STRONG SOUTHERLY FLOW COULD SEE HIGHER
AMOUNTS DUE TO TOPOGRAPHY ENHANCEMENTS. RAIN FALL RECORDS MAY FALL
IF EVERYTHING FALLS INTO PLACE.

ALSO BELIEVE THAT WE MAY SEE SOME WIND ISSUES WITH THIS SYSTEM.
GUIDANCE RIGHT NOW IS SHOWING A 45 TO 55 KT JET AT 925 MB...HOWEVER
IT WILL BE HARD TO BREAK THE INVERSION WITH THE SOUTHERLY FLOW.
RIGHT NOW BELIEVE THAT WIND ADVISORIES MAY BE NEEDED BUT IF THIS
SYSTEM STRENGTHEN EVEN MORE SO A STRONGER JET IS POSSIBLE.

CONTINUED THE MENTIONED OF ISOLATED THUNDER IN THE FORECAST PER PREV
FORECASTER SUGGESTION. BELIEVE IT COULD BE POSSIBLE AS SOUTHERN NEW
ENGLAND WILL BE IN THE WARM SECTOR...WITH THE ANOMALOUS JET AND
SHOWALTERS CLOSE TO ZERO.

FRIDAY...LOW CONFIDENCE.

ONCE UPPER LEVEL LOW MOVES INTO SOUTHERN CANADA...EXPECT A RATHER
FAST UPPER W FLOW IN PLACE. MAY SEE LEFTOVER SNOW SHOWERS BUT TEMPS
WILL FALL BACK CLOSE TO SEASONAL NORMS.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /THROUGH SUNDAY/...

THROUGH 00Z...MODERATE CONFIDENCE. MVFR CIGS WILL CONTINUE TO
OVERSPREAD EASTERN NEW ENGLAND AND EVENTUALLY OVERSPREAD THE INTERIOR
THIS AFTERNOON. SCATTERED SHOWERS ACROSS PORTIONS OF EASTERN
MASSACHUSETTS THIS AFTERNOON. MAINLY SNOW SHOWERS TO THE NORTH AND
WEST OF CAPE COD CANAL...RAIN SHOWERS SOUTH AND EAST. LOCALIZED
IFR CONDITIONS POSSIBLE JUST INLAND FROM THE SOUTHEAST NEW ENGLAND
COAST...WHERE SNOW IS FALLING.

TONIGHT AND SUNDAY...MODERATE CONFIDENCE.  MVFR CONDITIONS DOMINATE
IN LOWER CLOUDS AND SCATTERED SHOWERS. LOCALIZED IFR CONDITIONS
POSSIBLE WITH THE BEST CHANCE IN SNOW SHOWERS. PRECIPITATION
AFFECTS MAINLY EASTERN NEW ENGLAND BUT STILL SOME SCATTERED
ACTIVITY ACROSS WESTERN NEW ENGLAND. MAINLY SNOW SHOWERS TO THE
NORTH AND WEST OF CAPE COD CANAL...RAIN SHOWERS SOUTH AND EAST.

KBOS TERMINAL...MODERATE CONFIDENCE IN TAF. FLURRIES AND SNOW
SHOWERS MAY AFFECT THE TERMINAL BY 21Z.

KBDL TERMINAL...MODERATE CONFIDENCE IN TAF.

OUTLOOK...SUNDAY NIGHT THROUGH WEDNESDAY...

MONDAY INTO TUESDAY...MODERATE CONFIDENCE. EXPECT MOSTLY
VFR...ISOLATED MVFR ALONG THE MASS EAST COASTLINE IN RAIN/SNOW
SHOWERS.

TUESDAY NIGHT INTO WEDNESDAY...MODERATE CONFIDENCE. CONDITIONS WILL
BE DETERIORATING AS HEAVY DOWNPOURS...ISO THUNDER AND GUSTY SOUTHERLY
WINDS MOVE INTO THE REGION BY WEDNESDAY. COULD SEE MVFR TO IFR
CONDITIONS IN CIGS AND VSBYS.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /TODAY THROUGH SUNDAY/...HIGH CONFIDENCE.

HIGH PRESSURE ACROSS QUEBEC WILL RESULT IN PERSISTENT NORTHEAST
WINDS ACROSS THE WATERS THROUGH THE WEEKEND.  WIND GUSTS UP TO 20
KNOTS WITH SEAS BETWEEN 2 AND 4 FEET ARE EXPECTED FOR MOST
WATERS...SO NO HEADLINES PLANNED. THERE IS A LOW PROBABILITY THAT A
BRIEF SURGE OF NORTHEAST WIND GUSTS NEAR 25 KNOTS WITH MARGINAL 5
FOOT SEAS COULD AFFECT OUR NORTHERN WATERS LATE TONIGHT INTO SUN
MORNING...BUT NOT CONFIDENT ENOUGH TO ISSUE ANY HEADLINES AT THIS
POINT.

OUTLOOK...SUNDAY NIGHT INTO WEDNESDAY...MODERATE TO HIGH
CONFIDENCE.

SUNDAY INTO MONDAY. CONTINUOUS NORTHEAST FLOW WILL KEEP SEAS CHOPPY.
LINGERING NORTHEAST SWELL MAY BUMP SEAS ABOVE 5FT ESP ACROSS THE
NORTHEASTERN WATERS. SCA MAY BE NEEDED...BUT LOWER CONFIDENCE.

TUESDAY INTO WEDNESDAY...NE WINDS WILL INCREASE...GUSTING TO 30 KT
TUE THEN SHIFT TO SE GUSTING TO 30-35 KT WED...HIGHEST ON THE OUTER
WATERS. SEAS BUILD UP TO 7-11 FT BY WED. GALES WILL BE NEEDED.

&&

.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES WILL OCCUR TUESDAY THROUGH THURSDAY. BREAKING
IT DOWN...ON TUESDAY HIGH TIDE AT BOSTON WILL BE 11.6 FT. THERE WILL
BE ONSHORE FLOW DURING THIS HIGH TIDE ALLOWING FOR MINOR SPLASHOVER.
IF WIND GUSTS INCREASE THEN COULD POSSIBLE SEE MINOR COASTAL
FLOODING.

ON WEDNESDAY...WINDS WILL SWITCH TO A MORE SOUTHEASTERLY FLOW DURING
THE DAY AND INCREASE QUICKLY FROM APPROACHING SYSTEM AND DESCENT
PRESSURE FALLS. WEDNESDAY AFTERNOON HIGH TIDE IN BOSTON IS 11.7 FT
AND WITH ANY STRENGTH ON THE EASTERLY WIND FLOW WILL PUSH THE TIDE
OVER. RIGHT NOW BELIEVE MINOR COASTAL FLOODING IS POSSIBLE ALONG THE
EAST COASTLINE. HOWEVER WEDNESDAY EVENING...THE WIND GOES IN A MORE
SOUTHERLY DIRECTION AND HIGH TIDE IN PROVIDENCE WILL BE 5.2 FT. 925
MB LLJ STRENGTHENS TO 50-60 KTS WHICH COULD PUSH A DESCENT SURGE UP
ALONG THE SOUTH COAST DURING THE TIME OF HIGH TIDE. THINKING THAT
MINOR COASTAL FLOODING COULD OCCUR BUT CANNOT RULE OUT MODERATE
ALONG THE SOUTH COAST...ESP IF LLJ STRENGTHENS EVEN MORE.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...DUNTEN/RLG
NEAR TERM...FRANK/RLG
SHORT TERM...FRANK
LONG TERM...DUNTEN
AVIATION...DUNTEN/RLG
MARINE...FRANK/DUNTEN
TIDES/COASTAL FLOODING...




000
FXUS61 KBOX 201458
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
958 AM EST SAT DEC 20 2014

.SYNOPSIS...
SCATTERED SNOW/RAIN SHOWERS WILL GRADUALLY OVERSPREAD THE REGION
FROM EAST TO WEST LATER TODAY INTO SUN. WEAK LOW PRESSURE WILL
PASS SOUTH OF NEW ENGLAND BRINGING ANOTHER PERIOD OF PRECIP MON
NIGHT AND TUE. A MUCH STRONGER STORM PASSING WEST OF NEW ENGLAND
WILL BRING HEAVY RAINFALL...GUSTY WINDS AND COASTAL FLOODING
CONCERNS TO THE REGION WED INTO WED EVENING. DRY BUT VERY WINDY
CONDITIONS FOLLOW FOR CHRISTMAS DAY INTO FRI.

&&

.NEAR TERM /UNTIL NOON TODAY/...
10 AM UPDATE...MADE MINOR UPDATES MAINLY TO THE WINDS AND POPS.
UPDATED WINDS USING THE RAP FOR ITS HIGHER DETAIL WITH THE COASTAL
FRONT THIS AFTERNOON. SNOW SHOWERS HAVE MOVED ASHORE IN PLYMOUTH
COUNTY AS WELL AS PORTIONS OF THE CAPE AND THE EASTERN END OF CAPE
ANN. EXPECT THESE TO CONTINUE OFF AND ON THROUGH THE REMAINDER OF
THE MORNING.

SATELLITE IMAGERY SHOWS AN INTERESTING PATTERN. LOW CLOUDS MOVING
WESTWARD OFF THE OCEAN HAVE CREPT IN ALONG THE EAST COAST. THEN
ANOTHER AREA OF LOW CLOUDS HAVE MOVED NORTHWARD TOO ABOUT THE MASS
PIKE. NORTHWESTERN MASS SHOULD REMAIN MOSTLY SUNNY THROUGH THE
MORNING AND INTO THE AFTERNOON WHILE CLOUDS CONTINUE TO MOVE
WESTWARD ACROSS EASTERN MASSACHUSETTS.

&&

.SHORT TERM /NOON TODAY THROUGH 6 PM SUNDAY/...
THIS AFTERNOON AND TONIGHT...

INTERESTING MESOSCALE SETUP AS AN INVERTED TROUGH COMBINES WITH SOME
OCEAN ENHANCEMENT.  APPROACHING UPPER LEVEL SHORTWAVE WILL ALLOW FOR
EASTERLY FLOW JUST OFF THE GROUND.  THIS COMBINED WITH NORTHEAST
SURFACE WINDS WILL ALLOW LOW LEVEL OF THE ATMOSPHERE TO MOISTEN.
SOUNDINGS ACROSS EASTERN NEW ENGLAND BECOME SATURATED ALL THE WAY UP
TO THE -9C LAYER JUST ABOVE 850 MB.  THIS IS FAVORABLE FOR SOME
DECENT SNOW GROWTH...ITS JUST LOWER IN THE ATMOSPHERE THAN WE
TYPICALLY SEE WITH MORE SYNOPTIC SNOW EVENTS.  WHILE THIS IS NOT A
TRUE OCEAN EFFECT EVENT...DELTA T VALUES FROM THE MIXED LAYER TO THE
OCEAN ARE AROUND 15C.  THEREFORE...EXPECT SOME OCEAN ENHANCEMENT.

TIMING:

WHILE FLURRIES/LIGHT SNOW SHOWERS MAY OCCUR ACROSS FAR SOUTHEAST NEW
ENGLAND THIS MORNING.  THE MORE SUBSTANTIAL  PRECIPITATION SHOULD
OVERSPREAD PLYMOUTH COUNTY AS WELL AS THE CAPE AND ISLANDS THIS
AFTERNOON.  GIVEN EASTERLY FLOW JUST OFF THE GROUND...EXPECT SNOW
SHOWERS TO OVERSPREAD MOST OF EASTERN NEW ENGLAND THIS EVENING AS
LOW LEVELS MOISTEN.  IN FACT...SHOULD SEE AT LEAST SOME SCATTERED
SNOW SHOWERS AFFECT EVEN OUR FAR WESTERN ZONES.

PTYPE:

MAINLY SNOW FOR ALL BUT PORTIONS OF COASTAL PLYMOUTH COUNTY AND ONTO
THE CAPE/ISLANDS.  A SUBTLE COASTAL FRONT LOOKS TO SETUP ACROSS
SOUTHEAST COASTAL PLYMOUTH COUNTY.  PTYPE WILL BE SNOW TO THE
NORTHWEST OF THIS REGION...BUT ENOUGH MILD AIR SHOULD COME IN OFF
THE OCEAN FOR A CHANGE TO RAIN SHOWERS SOUTHEAST OF THIS REGION.
NOT EXPECTING THE POSITION OF THIS SUBTLE BOUNDARY TO CHANGE MUCH
THROUGH SUNDAY MORNING.

SNOW ACCUMULATIONS:

WE ARE GENERALLY LOOKING AT A COATING TO 2 INCHES OF SNOW ACROSS
MOST OF THE REGION.  THE MAIN FOCUS FOR 1 TO 2 INCHES WILL BE ACROSS
PORTIONS OF SOUTHEAST MA...AWAY FROM THE SOUTHEAST PLYMOUTH COUNTY
COAST.  ALSO...THE WORCESTER HILLS INTO NORTHWEST RHODE ISLAND MIGHT
BE ANOTHER AREA AS A RESULT OF THE SUBTLE UPSLOPE COMPONENT TO THE
WIND.  YOU CAN ACTUALLY SEE THAT IN SOME OF THE HIGH RESOLUTION
MODEL GUIDANCE.

THERE IS ONE AREA TO WATCH IN PARTICULAR...FROM NORTHWEST PLYMOUTH
COUNTY AND INTO NORFOLK COUNTY BASED ON MESOSCALE MODELS AND PATTERN
RECOGNITION.  WOULD NOT BE SURPRISED TO SEE VERY LOCALIZED 3 TO 4
INCH SNOW AMOUNTS...GIVEN SOME OCEAN ENHANCEMENT AND A LITTLE FOCUS
ON THE COASTAL FRONT.  WILL TRY TO HIGHLIGHT THIS AREA IN OUR
SNOWFALL AND PROBABILISTIC  GRAPHICS.

SUNDAY...

SCATTERED SNOW SHOWERS WILL CONTINUE DURING THE MORNING WITH MOIST
EASTERLY FLOW IN THE LOW LEVELS. AGAIN...PTYPE WILL BE SNOW EXCEPT
ACROSS SOUTHEAST PLYMOUTH COUNTY/CAPE AND ISLANDS WHERE BOUNDARY
LAYER WILL PROBABLY BE WARM ENOUGH FOR RAIN SHOWERS.  WHILE SOME
LIGHT PRECIPITATION MAY LINGER INTO SUNDAY AFTERNOON...EXPECT A
DECREASE IN AREAL COVERAGE THROUGH THE AFTERNOON AS LOW LEVEL LIFT
WEAKENS.  IT WILL REMAIN CLOUDY THOUGH WITH TEMPS IN THE 30S.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
HIGHLIGHTS...

* INVERTED TROUGH WILL BRING RAIN/SNOW SHOWERS TO THE MASS EAST
  COASTLINE MONDAY INTO TUES MORNING.
* WEAK WAVE OF LOW PRESSURE MON NIGHT/TUESDAY COULD BRING WINTRY
  MIX TO INTERIOR
* ANOMALOUS SYSTEM ACROSS THE GREAT LAKES WILL BRING HEAVY
  RAIN...GUSTY WINDS AND COASTAL FLOODING CONCERNS AROUND CHRISTMAS
  EVE

OVERVIEW...

OVERALL 00Z GUIDANCE IS IN AGREEMENT SYNOPTICALLY WITH ISSUES ON
TIMING AND SMALLER SCALE FEATURES. IT REMAINS EVIDENT THAT AN
AMPLIFIED MID-UPPER LEVEL TROUGH AND PCPN FOCUSING LEAD SURFACE
LOW/FRONTAL SYSTEM WILL STEADILY PROGRESS TO THE EAST-CENTRAL U.S.
TUE AS EMBEDDED IMPULSES DIG TO THE LEE OF AN AMPLIFIED ERN
PACIFIC/WEST COAST RIDGE ALOFT. THE SUPPORTING AND INCREASINGLY
NEGATIVE-TILT TROUGH ALOFT WORKS OVER THE ERN US AND OUT THROUGH THE
NERN STATES INTO DAYS 4/5 WED/THU.  MODELS/ENSEMBLES HAVE BEEN
FAIRLY CONSISTENT ON THIS AMPLIFIED PATTERN AND THE MOST RECENT
GEFS/ECMWF ENSEMBLE GUIDANCE SHOW GOOD CORRELATION TO NEXT THURSDAY.

HIGH PRESSURE AND UPPER LEVEL RIDGE OVER THE REGION WILL BEGIN TO
EXIT BY MONDAY. AT THE SURFACE APPEARS ANOTHER INVERTED
TROUGH/ONSHORE FLOW WILL YIELD TO PRECIP ALONG THE MASS COASTLINE ON
MONDAY. ASIDE FROM THIS QUICK MESOSCALE EVENT THE MAIN FOCUS IS ON
THE LONGWAVE DIGGING TROUGH OVER THE CENTRAL CONUS WHICH WILL PUSH A
FEW SHORTWAVES THROUGH THE FLOW. FIRST ONE DEVELOPS A WEAK WAVE
MOVING TOWARDS THE REGION LATE MONDAY INTO TUESDAY. THERE IS STILL
SOME UNCERTAINTY WITH THE LOCATION/STRENGTH OF THIS SYSTEM BUT
APPEARS THAT THERE IS THE POSSIBILITY OF A SNOW/WINTRY MIX IN THE
INTERIOR. AS THIS SYSTEM DEPARTS AN ANOMALOUS LOW OVER THE GREAT
LAKES WILL DEVELOP A SECONDARY LOW JUST WEST OF SOUTHERN NEW ENGLAND
     PER ENSEMBLE GUIDANCE. STILL A SOME SPREAD BUT IF THIS DOUBLE LOW
DOES DEVELOP THEN THE RAIN AND WIND ASPECT OF THE SYSTEM
INCREASES...DETAILS BELOW. STILL NEED TO WORK OUT MINOR DETAILS WITH
THIS PARTICULAR SYSTEM BUT WITH 3 TO 4 STANDARD DEVIATIONS AWAY AND
GENERAL MODEL AGREEMENT HAVE HIGH CONFIDENCE THIS SYSTEM WILL IMPACT
SOUTHERN NEW ENGLAND.

DETAILS...

SUNDAY NIGHT INTO TUESDAY...MODERATE CONFIDENCE.

HIGH PRESSURE AND UPPER LEVEL RIDGE WILL BEGIN TO MOVE OFFSHORE AS
DIGGING TROUGH BEGINS TO SET-UP OVER THE CENTRAL CONUS. APPEARS
ANOTHER MESO-SCALE INVERTED TROUGH WILL SET UP ON MONDAY AND LAST
INTO EARLY TUESDAY MORNING. GUIDANCE SHOWS THAT RAIN/SNOW SHOWERS
WILL DEVELOP ALONG THE MASS EAST COASTLINE THANKS TO ONSHORE
EASTERLY FLOW. APPEARS THE COLUMN WILL SATURATE PER BUFKIT SOUNDINGS
AND SOUTHERLY FLOW ALOFT. BOTH THE NAM AND GFS SHOW QPF MAKING IT
ONSHORE DURING THIS TIME FRAME. HOWEVER THE EC IS SLIGHTLY SLOWER
AND KEEP THE BULK OF THE PRECIP JUST OFFSHORE. ADD A CHANCE OF POPS
DUE TO THE NAM/GFS MODEL CONTINUITY.

BY LATE MONDAY NIGHT INTO TUESDAY A SOUTHERN BRANCH STORM SYSTEM
FORMS ALONG THE SE COAST AND TAKES A TRACK OFF THE MID ATLANTIC
COAST. THIS SYSTEM GETS CAUGHT UP WITH THE OVERALL LARGE SCALE
AMPLIFICATION OF THE UPPER AIR PATTERN. THERE IS DECENT WARM
ADVECTION WITH COLD AIR DAMMING ACROSS THE INTERIOR. BIGGEST
QUESTION WILL BE IS THERE ENOUGH MOISTURE FOR PRECIP DURING THIS
TIME FRAME. IF PRECIP OVERRUNS THEN COULD SEE FREEZING RAIN/DRIZZLE
ACROSS THE INTERIOR LATE MONDAY INTO TUESDAY MORNING. DURING THE DAY
ON TUESDAY...GOOD AMOUNT OF WARM AIR WILL PUSH SURFACE TEMPS ABOVE
FREEZING ALLOWING FOR ANY PRECIP TO BE MORE OF THE LIQUID VARIETY
AHEAD OF THE CHRISTMAS EVE STORM. HOWEVER GUIDANCE IS ALWAYS TOO
FAST IN SCOURING TEMPS OUT ESP ACROSS THE CT VALLEY SO WE WILL NEED
TO MONITOR THIS CLOSELY...ESP DUE TO LIGHT WINDS AND THE HIGH IN
EASTERN CANADA.

WE COULD ALSO SEE SOME MINOR COASTAL FLOODING CONCERNS ON TUESDAY. SEE
BELOW FOR MORE DETAILS.

WEDNESDAY INTO THURSDAY...HIGH CONFIDENCE IN SYSTEM LOW CONFIDENCE
ON DETAILS.

STRONG ANOMALOUS SYSTEM WILL STRENGTHEN OVER THE GREAT
LAKES...DEVELOPING A POTENTIAL SECONDARY SURFACE LOW JUST WEST OF
SOUTHERN NEW ENGLAND. STILL A LOT OF DETAILS TO WORK OUT AS THIS
SYSTEM IS STILL 5 DAYS AWAY...HOWEVER ENSEMBLES CONTINUE TO SHOW
STRONG AGREEMENT SO HAVE INCREASING CONFIDENCE THAT A POTENT STORM
WILL OCCUR. LATEST 00Z GUIDANCE SHOWS THAT MOST PRECIP WILL BE
LIQUID WITH A DEEP SUBTROPICAL CONNECTION BACK ACROSS THE GULF OF
MEXICO...PW ANOMALIES FORECAST TO RISE BETWEEN +3 TO +4. CURRENT
PWATS ARE PROGGED ABOVE 1.6 INCHES SO HAVE CONTINUED THE CATEGORICAL
POPS. TEMPERATURES WILL BE WELL ABOVE AVERAGE...IN FACT WE MAY BE
CLOSE AT BREAKING RECORD HIGH TEMPS IF TEMPS WARM TO 60F OR ABOVE ON
CHRISTMAS EVE.  AS THE SYSTEM WRAPS UP INTO CANADA...COLD AIR
ADVECTION SHOULD CIRCULATE AROUND AND BEGIN A TRANSITION FROM
SOUTHWEST TO NORTHEAST IN TURNING P-TYPE TO SNOW. HOWEVER LATEST
GUIDANCE DOES SHOW A QUICK MOVING DRY SLOT SO SNOWFALL WILL STRUGGLE
DUE TO LACK OF MOISTURE.

THIS SYSTEM IS QUITE POTENT SO WE WILL NEED TO WATCH FOR POTENTIAL
HAZARDS. CURRENTLY THINK THAT WE COULD POSSIBLE URBAN FLOODING
ISSUES AS MODELS PROGGED WELL OVER 1.5 INCHES OF QPF. LATEST EC EVEN
SHOWS 2.5 INCHES OF QPF IS POSSIBLE. THE GEFS SHOW A MOISTURE FLUX
AT 850 MB BEING 4 TO 5 STANDARD DEVIATIONS AWAY...AND WITH THE
TROPICAL CONNECTION AND STRONG SOUTHERLY FLOW COULD SEE HIGHER
AMOUNTS DUE TO TOPOGRAPHY ENHANCEMENTS. RAIN FALL RECORDS MAY FALL
IF EVERYTHING FALLS INTO PLACE.

ALSO BELIEVE THAT WE MAY SEE SOME WIND ISSUES WITH THIS SYSTEM.
GUIDANCE RIGHT NOW IS SHOWING A 45 TO 55 KT JET AT 925 MB...HOWEVER
IT WILL BE HARD TO BREAK THE INVERSION WITH THE SOUTHERLY FLOW.
RIGHT NOW BELIEVE THAT WIND ADVISORIES MAY BE NEEDED BUT IF THIS
SYSTEM STRENGTHEN EVEN MORE SO A STRONGER JET IS POSSIBLE.

CONTINUED THE MENTIONED OF ISOLATED THUNDER IN THE FORECAST PER PREV
FORECASTER SUGGESTION. BELIEVE IT COULD BE POSSIBLE AS SOUTHERN NEW
ENGLAND WILL BE IN THE WARM SECTOR...WITH THE ANOMALOUS JET AND
SHOWALTERS CLOSE TO ZERO.

FRIDAY...LOW CONFIDENCE.

ONCE UPPER LEVEL LOW MOVES INTO SOUTHERN CANADA...EXPECT A RATHER
FAST UPPER W FLOW IN PLACE. MAY SEE LEFTOVER SNOW SHOWERS BUT TEMPS
WILL FALL BACK CLOSE TO SEASONAL NORMS.

&&

.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 /THROUGH SUNDAY/...

700 AM UPDATE...

TODAY...MODERATE CONFIDENCE.  MVFR CIGS WILL CONTINUE TO OVERSPREAD
EASTERN NEW ENGLAND THIS MORNING AND EVENTUALLY INTO THE INTERIOR
THIS AFTERNOON.  SCATTERED PRECIPITATION WILL OVERSPREAD
SOUTHEAST MA/CAPE/ISLANDS THIS AFTERNOON.  PTYPE MAINLY SNOW SHOWERS
NORTHWEST OF THE SOUTHEAST PLYMOUTH COUNTY COAST AND RAIN SHOWERS
SOUTHEAST OF THAT REGION. LOCALIZED IFR CONDITIONS POSSIBLE JUST
INLAND FROM THE SOUTHEAST NEW ENGLAND COAST...WHERE PTYPE IS SNOW.

TONIGHT AND SUNDAY...MODERATE CONFIDENCE.  MVFR CONDITIONS DOMINATE
IN LOWER CLOUDS AND SCATTERED PRECIPITATION.  LOCALIZED IFR
CONDITIONS POSSIBLE WITH THE BEST CHANCE IN SNOW SHOWERS.
PRECIPITATION AFFECTS MAINLY EASTERN NEW ENGLAND BUT STILL SOME
SCATTERED ACTIVITY ACROSS WESTERN NEW ENGLAND. PTYPE MAINLY SNOW
SHOWERS NORTHWEST OF THE SOUTHEAST PLYMOUTH COUNTY COAST...WITH RAIN
SHOWERS SOUTHEAST OF THAT REGION.

KBOS TERMINAL...MODERATE CONFIDENCE IN TAF.  SNOW SHOWERS MAY ARRIVE
TOWARDS 00Z THIS EVENING.

KBDL TERMINAL...MODERATE CONFIDENCE IN TAF.

OUTLOOK...SUNDAY NIGHT THROUGH WEDNESDAY...

MONDAY INTO TUESDAY...MODERATE CONFIDENCE. EXPECT MOSTLY
VFR...ISOLATED MVFR ALONG THE MASS EAST COASTLINE IN RAIN/SNOW
SHOWERS.

TUESDAY NIGHT INTO WEDNESDAY...MODERATE CONFIDENCE. CONDITIONS WILL
BE DETERIORATING AS HEAVY DOWNPOURS...ISO THUNDER AND GUSTY SOUTHERLY
WINDS MOVE INTO THE REGION BY WEDNESDAY. COULD SEE MVFR TO IFR
CONDITIONS IN CIGS AND VSBYS.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /TODAY THROUGH SUNDAY/...HIGH CONFIDENCE.

HIGH PRESSURE ACROSS QUEBEC WILL RESULT IN PERSISTENT NORTHEAST
WINDS ACROSS THE WATERS THROUGH THE WEEKEND.  WIND GUSTS UP TO 20
KNOTS WITH SEAS BETWEEN 2 AND 4 FEET ARE EXPECTED FOR MOST
WATERS...SO NO HEADLINES PLANNED. THERE IS A LOW PROBABILITY THAT A
BRIEF SURGE OF NORTHEAST WIND GUSTS NEAR 25 KNOTS WITH MARGINAL 5
FOOT SEAS COULD AFFECT OUR NORTHERN WATERS LATE TONIGHT INTO SUN
MORNING...BUT NOT CONFIDENT ENOUGH TO ISSUE ANY HEADLINES AT THIS
POINT.

OUTLOOK...SUNDAY NIGHT INTO WEDNESDAY...MODERATE TO HIGH
CONFIDENCE.

SUNDAY INTO MONDAY. CONTINUOUS NORTHEAST FLOW WILL KEEP SEAS CHOPPY.
LINGERING NORTHEAST SWELL MAY BUMP SEAS ABOVE 5FT ESP ACROSS THE
NORTHEASTERN WATERS. SCA MAY BE NEEDED...BUT LOWER CONFIDENCE.

TUESDAY INTO WEDNESDAY...NE WINDS WILL INCREASE...GUSTING TO 30 KT
TUE THEN SHIFT TO SE GUSTING TO 30-35 KT WED...HIGHEST ON THE OUTER
WATERS. SEAS BUILD UP TO 7-11 FT BY WED. GALES WILL BE NEEDED.

&&

.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES WILL OCCUR TUESDAY THROUGH THURSDAY. BREAKING
IT DOWN...ON TUESDAY HIGH TIDE AT BOSTON WILL BE 11.6 FT. THERE WILL
BE ONSHORE FLOW DURING THIS HIGH TIDE ALLOWING FOR MINOR SPLASHOVER.
IF WIND GUSTS INCREASE THEN COULD POSSIBLE SEE MINOR COASTAL
FLOODING.

ON WEDNESDAY...WINDS WILL SWITCH TO A MORE SOUTHEASTERLY FLOW DURING
THE DAY AND INCREASE QUICKLY FROM APPROACHING SYSTEM AND DESCENT
PRESSURE FALLS. WEDNESDAY AFTERNOON HIGH TIDE IN BOSTON IS 11.7 FT
AND WITH ANY STRENGTH ON THE EASTERLY WIND FLOW WILL PUSH THE TIDE
OVER. RIGHT NOW BELIEVE MINOR COASTAL FLOODING IS POSSIBLE ALONG THE
EAST COASTLINE. HOWEVER WEDNESDAY EVENING...THE WIND GOES IN A MORE
SOUTHERLY DIRECTION AND HIGH TIDE IN PROVIDENCE WILL BE 5.2 FT. 925
MB LLJ STRENGTHENS TO 50-60 KTS WHICH COULD PUSH A DESCENT SURGE UP
ALONG THE SOUTH COAST DURING THE TIME OF HIGH TIDE. THINKING THAT
MINOR COASTAL FLOODING COULD OCCUR BUT CANNOT RULE OUT MODERATE
ALONG THE SOUTH COAST...ESP IF LLJ STRENGTHENS EVEN MORE.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...FRANK/DUNTEN
NEAR TERM...FRANK/DUNTEN/RLG
SHORT TERM...FRANK
LONG TERM...DUNTEN
AVIATION...FRANK/DUNTEN
MARINE...FRANK/DUNTEN
TIDES/COASTAL FLOODING...




000
FXUS61 KBOX 201458
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
958 AM EST SAT DEC 20 2014

.SYNOPSIS...
SCATTERED SNOW/RAIN SHOWERS WILL GRADUALLY OVERSPREAD THE REGION
FROM EAST TO WEST LATER TODAY INTO SUN. WEAK LOW PRESSURE WILL
PASS SOUTH OF NEW ENGLAND BRINGING ANOTHER PERIOD OF PRECIP MON
NIGHT AND TUE. A MUCH STRONGER STORM PASSING WEST OF NEW ENGLAND
WILL BRING HEAVY RAINFALL...GUSTY WINDS AND COASTAL FLOODING
CONCERNS TO THE REGION WED INTO WED EVENING. DRY BUT VERY WINDY
CONDITIONS FOLLOW FOR CHRISTMAS DAY INTO FRI.

&&

.NEAR TERM /UNTIL NOON TODAY/...
10 AM UPDATE...MADE MINOR UPDATES MAINLY TO THE WINDS AND POPS.
UPDATED WINDS USING THE RAP FOR ITS HIGHER DETAIL WITH THE COASTAL
FRONT THIS AFTERNOON. SNOW SHOWERS HAVE MOVED ASHORE IN PLYMOUTH
COUNTY AS WELL AS PORTIONS OF THE CAPE AND THE EASTERN END OF CAPE
ANN. EXPECT THESE TO CONTINUE OFF AND ON THROUGH THE REMAINDER OF
THE MORNING.

SATELLITE IMAGERY SHOWS AN INTERESTING PATTERN. LOW CLOUDS MOVING
WESTWARD OFF THE OCEAN HAVE CREPT IN ALONG THE EAST COAST. THEN
ANOTHER AREA OF LOW CLOUDS HAVE MOVED NORTHWARD TOO ABOUT THE MASS
PIKE. NORTHWESTERN MASS SHOULD REMAIN MOSTLY SUNNY THROUGH THE
MORNING AND INTO THE AFTERNOON WHILE CLOUDS CONTINUE TO MOVE
WESTWARD ACROSS EASTERN MASSACHUSETTS.

&&

.SHORT TERM /NOON TODAY THROUGH 6 PM SUNDAY/...
THIS AFTERNOON AND TONIGHT...

INTERESTING MESOSCALE SETUP AS AN INVERTED TROUGH COMBINES WITH SOME
OCEAN ENHANCEMENT.  APPROACHING UPPER LEVEL SHORTWAVE WILL ALLOW FOR
EASTERLY FLOW JUST OFF THE GROUND.  THIS COMBINED WITH NORTHEAST
SURFACE WINDS WILL ALLOW LOW LEVEL OF THE ATMOSPHERE TO MOISTEN.
SOUNDINGS ACROSS EASTERN NEW ENGLAND BECOME SATURATED ALL THE WAY UP
TO THE -9C LAYER JUST ABOVE 850 MB.  THIS IS FAVORABLE FOR SOME
DECENT SNOW GROWTH...ITS JUST LOWER IN THE ATMOSPHERE THAN WE
TYPICALLY SEE WITH MORE SYNOPTIC SNOW EVENTS.  WHILE THIS IS NOT A
TRUE OCEAN EFFECT EVENT...DELTA T VALUES FROM THE MIXED LAYER TO THE
OCEAN ARE AROUND 15C.  THEREFORE...EXPECT SOME OCEAN ENHANCEMENT.

TIMING:

WHILE FLURRIES/LIGHT SNOW SHOWERS MAY OCCUR ACROSS FAR SOUTHEAST NEW
ENGLAND THIS MORNING.  THE MORE SUBSTANTIAL  PRECIPITATION SHOULD
OVERSPREAD PLYMOUTH COUNTY AS WELL AS THE CAPE AND ISLANDS THIS
AFTERNOON.  GIVEN EASTERLY FLOW JUST OFF THE GROUND...EXPECT SNOW
SHOWERS TO OVERSPREAD MOST OF EASTERN NEW ENGLAND THIS EVENING AS
LOW LEVELS MOISTEN.  IN FACT...SHOULD SEE AT LEAST SOME SCATTERED
SNOW SHOWERS AFFECT EVEN OUR FAR WESTERN ZONES.

PTYPE:

MAINLY SNOW FOR ALL BUT PORTIONS OF COASTAL PLYMOUTH COUNTY AND ONTO
THE CAPE/ISLANDS.  A SUBTLE COASTAL FRONT LOOKS TO SETUP ACROSS
SOUTHEAST COASTAL PLYMOUTH COUNTY.  PTYPE WILL BE SNOW TO THE
NORTHWEST OF THIS REGION...BUT ENOUGH MILD AIR SHOULD COME IN OFF
THE OCEAN FOR A CHANGE TO RAIN SHOWERS SOUTHEAST OF THIS REGION.
NOT EXPECTING THE POSITION OF THIS SUBTLE BOUNDARY TO CHANGE MUCH
THROUGH SUNDAY MORNING.

SNOW ACCUMULATIONS:

WE ARE GENERALLY LOOKING AT A COATING TO 2 INCHES OF SNOW ACROSS
MOST OF THE REGION.  THE MAIN FOCUS FOR 1 TO 2 INCHES WILL BE ACROSS
PORTIONS OF SOUTHEAST MA...AWAY FROM THE SOUTHEAST PLYMOUTH COUNTY
COAST.  ALSO...THE WORCESTER HILLS INTO NORTHWEST RHODE ISLAND MIGHT
BE ANOTHER AREA AS A RESULT OF THE SUBTLE UPSLOPE COMPONENT TO THE
WIND.  YOU CAN ACTUALLY SEE THAT IN SOME OF THE HIGH RESOLUTION
MODEL GUIDANCE.

THERE IS ONE AREA TO WATCH IN PARTICULAR...FROM NORTHWEST PLYMOUTH
COUNTY AND INTO NORFOLK COUNTY BASED ON MESOSCALE MODELS AND PATTERN
RECOGNITION.  WOULD NOT BE SURPRISED TO SEE VERY LOCALIZED 3 TO 4
INCH SNOW AMOUNTS...GIVEN SOME OCEAN ENHANCEMENT AND A LITTLE FOCUS
ON THE COASTAL FRONT.  WILL TRY TO HIGHLIGHT THIS AREA IN OUR
SNOWFALL AND PROBABILISTIC  GRAPHICS.

SUNDAY...

SCATTERED SNOW SHOWERS WILL CONTINUE DURING THE MORNING WITH MOIST
EASTERLY FLOW IN THE LOW LEVELS. AGAIN...PTYPE WILL BE SNOW EXCEPT
ACROSS SOUTHEAST PLYMOUTH COUNTY/CAPE AND ISLANDS WHERE BOUNDARY
LAYER WILL PROBABLY BE WARM ENOUGH FOR RAIN SHOWERS.  WHILE SOME
LIGHT PRECIPITATION MAY LINGER INTO SUNDAY AFTERNOON...EXPECT A
DECREASE IN AREAL COVERAGE THROUGH THE AFTERNOON AS LOW LEVEL LIFT
WEAKENS.  IT WILL REMAIN CLOUDY THOUGH WITH TEMPS IN THE 30S.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
HIGHLIGHTS...

* INVERTED TROUGH WILL BRING RAIN/SNOW SHOWERS TO THE MASS EAST
  COASTLINE MONDAY INTO TUES MORNING.
* WEAK WAVE OF LOW PRESSURE MON NIGHT/TUESDAY COULD BRING WINTRY
  MIX TO INTERIOR
* ANOMALOUS SYSTEM ACROSS THE GREAT LAKES WILL BRING HEAVY
  RAIN...GUSTY WINDS AND COASTAL FLOODING CONCERNS AROUND CHRISTMAS
  EVE

OVERVIEW...

OVERALL 00Z GUIDANCE IS IN AGREEMENT SYNOPTICALLY WITH ISSUES ON
TIMING AND SMALLER SCALE FEATURES. IT REMAINS EVIDENT THAT AN
AMPLIFIED MID-UPPER LEVEL TROUGH AND PCPN FOCUSING LEAD SURFACE
LOW/FRONTAL SYSTEM WILL STEADILY PROGRESS TO THE EAST-CENTRAL U.S.
TUE AS EMBEDDED IMPULSES DIG TO THE LEE OF AN AMPLIFIED ERN
PACIFIC/WEST COAST RIDGE ALOFT. THE SUPPORTING AND INCREASINGLY
NEGATIVE-TILT TROUGH ALOFT WORKS OVER THE ERN US AND OUT THROUGH THE
NERN STATES INTO DAYS 4/5 WED/THU.  MODELS/ENSEMBLES HAVE BEEN
FAIRLY CONSISTENT ON THIS AMPLIFIED PATTERN AND THE MOST RECENT
GEFS/ECMWF ENSEMBLE GUIDANCE SHOW GOOD CORRELATION TO NEXT THURSDAY.

HIGH PRESSURE AND UPPER LEVEL RIDGE OVER THE REGION WILL BEGIN TO
EXIT BY MONDAY. AT THE SURFACE APPEARS ANOTHER INVERTED
TROUGH/ONSHORE FLOW WILL YIELD TO PRECIP ALONG THE MASS COASTLINE ON
MONDAY. ASIDE FROM THIS QUICK MESOSCALE EVENT THE MAIN FOCUS IS ON
THE LONGWAVE DIGGING TROUGH OVER THE CENTRAL CONUS WHICH WILL PUSH A
FEW SHORTWAVES THROUGH THE FLOW. FIRST ONE DEVELOPS A WEAK WAVE
MOVING TOWARDS THE REGION LATE MONDAY INTO TUESDAY. THERE IS STILL
SOME UNCERTAINTY WITH THE LOCATION/STRENGTH OF THIS SYSTEM BUT
APPEARS THAT THERE IS THE POSSIBILITY OF A SNOW/WINTRY MIX IN THE
INTERIOR. AS THIS SYSTEM DEPARTS AN ANOMALOUS LOW OVER THE GREAT
LAKES WILL DEVELOP A SECONDARY LOW JUST WEST OF SOUTHERN NEW ENGLAND
     PER ENSEMBLE GUIDANCE. STILL A SOME SPREAD BUT IF THIS DOUBLE LOW
DOES DEVELOP THEN THE RAIN AND WIND ASPECT OF THE SYSTEM
INCREASES...DETAILS BELOW. STILL NEED TO WORK OUT MINOR DETAILS WITH
THIS PARTICULAR SYSTEM BUT WITH 3 TO 4 STANDARD DEVIATIONS AWAY AND
GENERAL MODEL AGREEMENT HAVE HIGH CONFIDENCE THIS SYSTEM WILL IMPACT
SOUTHERN NEW ENGLAND.

DETAILS...

SUNDAY NIGHT INTO TUESDAY...MODERATE CONFIDENCE.

HIGH PRESSURE AND UPPER LEVEL RIDGE WILL BEGIN TO MOVE OFFSHORE AS
DIGGING TROUGH BEGINS TO SET-UP OVER THE CENTRAL CONUS. APPEARS
ANOTHER MESO-SCALE INVERTED TROUGH WILL SET UP ON MONDAY AND LAST
INTO EARLY TUESDAY MORNING. GUIDANCE SHOWS THAT RAIN/SNOW SHOWERS
WILL DEVELOP ALONG THE MASS EAST COASTLINE THANKS TO ONSHORE
EASTERLY FLOW. APPEARS THE COLUMN WILL SATURATE PER BUFKIT SOUNDINGS
AND SOUTHERLY FLOW ALOFT. BOTH THE NAM AND GFS SHOW QPF MAKING IT
ONSHORE DURING THIS TIME FRAME. HOWEVER THE EC IS SLIGHTLY SLOWER
AND KEEP THE BULK OF THE PRECIP JUST OFFSHORE. ADD A CHANCE OF POPS
DUE TO THE NAM/GFS MODEL CONTINUITY.

BY LATE MONDAY NIGHT INTO TUESDAY A SOUTHERN BRANCH STORM SYSTEM
FORMS ALONG THE SE COAST AND TAKES A TRACK OFF THE MID ATLANTIC
COAST. THIS SYSTEM GETS CAUGHT UP WITH THE OVERALL LARGE SCALE
AMPLIFICATION OF THE UPPER AIR PATTERN. THERE IS DECENT WARM
ADVECTION WITH COLD AIR DAMMING ACROSS THE INTERIOR. BIGGEST
QUESTION WILL BE IS THERE ENOUGH MOISTURE FOR PRECIP DURING THIS
TIME FRAME. IF PRECIP OVERRUNS THEN COULD SEE FREEZING RAIN/DRIZZLE
ACROSS THE INTERIOR LATE MONDAY INTO TUESDAY MORNING. DURING THE DAY
ON TUESDAY...GOOD AMOUNT OF WARM AIR WILL PUSH SURFACE TEMPS ABOVE
FREEZING ALLOWING FOR ANY PRECIP TO BE MORE OF THE LIQUID VARIETY
AHEAD OF THE CHRISTMAS EVE STORM. HOWEVER GUIDANCE IS ALWAYS TOO
FAST IN SCOURING TEMPS OUT ESP ACROSS THE CT VALLEY SO WE WILL NEED
TO MONITOR THIS CLOSELY...ESP DUE TO LIGHT WINDS AND THE HIGH IN
EASTERN CANADA.

WE COULD ALSO SEE SOME MINOR COASTAL FLOODING CONCERNS ON TUESDAY. SEE
BELOW FOR MORE DETAILS.

WEDNESDAY INTO THURSDAY...HIGH CONFIDENCE IN SYSTEM LOW CONFIDENCE
ON DETAILS.

STRONG ANOMALOUS SYSTEM WILL STRENGTHEN OVER THE GREAT
LAKES...DEVELOPING A POTENTIAL SECONDARY SURFACE LOW JUST WEST OF
SOUTHERN NEW ENGLAND. STILL A LOT OF DETAILS TO WORK OUT AS THIS
SYSTEM IS STILL 5 DAYS AWAY...HOWEVER ENSEMBLES CONTINUE TO SHOW
STRONG AGREEMENT SO HAVE INCREASING CONFIDENCE THAT A POTENT STORM
WILL OCCUR. LATEST 00Z GUIDANCE SHOWS THAT MOST PRECIP WILL BE
LIQUID WITH A DEEP SUBTROPICAL CONNECTION BACK ACROSS THE GULF OF
MEXICO...PW ANOMALIES FORECAST TO RISE BETWEEN +3 TO +4. CURRENT
PWATS ARE PROGGED ABOVE 1.6 INCHES SO HAVE CONTINUED THE CATEGORICAL
POPS. TEMPERATURES WILL BE WELL ABOVE AVERAGE...IN FACT WE MAY BE
CLOSE AT BREAKING RECORD HIGH TEMPS IF TEMPS WARM TO 60F OR ABOVE ON
CHRISTMAS EVE.  AS THE SYSTEM WRAPS UP INTO CANADA...COLD AIR
ADVECTION SHOULD CIRCULATE AROUND AND BEGIN A TRANSITION FROM
SOUTHWEST TO NORTHEAST IN TURNING P-TYPE TO SNOW. HOWEVER LATEST
GUIDANCE DOES SHOW A QUICK MOVING DRY SLOT SO SNOWFALL WILL STRUGGLE
DUE TO LACK OF MOISTURE.

THIS SYSTEM IS QUITE POTENT SO WE WILL NEED TO WATCH FOR POTENTIAL
HAZARDS. CURRENTLY THINK THAT WE COULD POSSIBLE URBAN FLOODING
ISSUES AS MODELS PROGGED WELL OVER 1.5 INCHES OF QPF. LATEST EC EVEN
SHOWS 2.5 INCHES OF QPF IS POSSIBLE. THE GEFS SHOW A MOISTURE FLUX
AT 850 MB BEING 4 TO 5 STANDARD DEVIATIONS AWAY...AND WITH THE
TROPICAL CONNECTION AND STRONG SOUTHERLY FLOW COULD SEE HIGHER
AMOUNTS DUE TO TOPOGRAPHY ENHANCEMENTS. RAIN FALL RECORDS MAY FALL
IF EVERYTHING FALLS INTO PLACE.

ALSO BELIEVE THAT WE MAY SEE SOME WIND ISSUES WITH THIS SYSTEM.
GUIDANCE RIGHT NOW IS SHOWING A 45 TO 55 KT JET AT 925 MB...HOWEVER
IT WILL BE HARD TO BREAK THE INVERSION WITH THE SOUTHERLY FLOW.
RIGHT NOW BELIEVE THAT WIND ADVISORIES MAY BE NEEDED BUT IF THIS
SYSTEM STRENGTHEN EVEN MORE SO A STRONGER JET IS POSSIBLE.

CONTINUED THE MENTIONED OF ISOLATED THUNDER IN THE FORECAST PER PREV
FORECASTER SUGGESTION. BELIEVE IT COULD BE POSSIBLE AS SOUTHERN NEW
ENGLAND WILL BE IN THE WARM SECTOR...WITH THE ANOMALOUS JET AND
SHOWALTERS CLOSE TO ZERO.

FRIDAY...LOW CONFIDENCE.

ONCE UPPER LEVEL LOW MOVES INTO SOUTHERN CANADA...EXPECT A RATHER
FAST UPPER W FLOW IN PLACE. MAY SEE LEFTOVER SNOW SHOWERS BUT TEMPS
WILL FALL BACK CLOSE TO SEASONAL NORMS.

&&

.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 /THROUGH SUNDAY/...

700 AM UPDATE...

TODAY...MODERATE CONFIDENCE.  MVFR CIGS WILL CONTINUE TO OVERSPREAD
EASTERN NEW ENGLAND THIS MORNING AND EVENTUALLY INTO THE INTERIOR
THIS AFTERNOON.  SCATTERED PRECIPITATION WILL OVERSPREAD
SOUTHEAST MA/CAPE/ISLANDS THIS AFTERNOON.  PTYPE MAINLY SNOW SHOWERS
NORTHWEST OF THE SOUTHEAST PLYMOUTH COUNTY COAST AND RAIN SHOWERS
SOUTHEAST OF THAT REGION. LOCALIZED IFR CONDITIONS POSSIBLE JUST
INLAND FROM THE SOUTHEAST NEW ENGLAND COAST...WHERE PTYPE IS SNOW.

TONIGHT AND SUNDAY...MODERATE CONFIDENCE.  MVFR CONDITIONS DOMINATE
IN LOWER CLOUDS AND SCATTERED PRECIPITATION.  LOCALIZED IFR
CONDITIONS POSSIBLE WITH THE BEST CHANCE IN SNOW SHOWERS.
PRECIPITATION AFFECTS MAINLY EASTERN NEW ENGLAND BUT STILL SOME
SCATTERED ACTIVITY ACROSS WESTERN NEW ENGLAND. PTYPE MAINLY SNOW
SHOWERS NORTHWEST OF THE SOUTHEAST PLYMOUTH COUNTY COAST...WITH RAIN
SHOWERS SOUTHEAST OF THAT REGION.

KBOS TERMINAL...MODERATE CONFIDENCE IN TAF.  SNOW SHOWERS MAY ARRIVE
TOWARDS 00Z THIS EVENING.

KBDL TERMINAL...MODERATE CONFIDENCE IN TAF.

OUTLOOK...SUNDAY NIGHT THROUGH WEDNESDAY...

MONDAY INTO TUESDAY...MODERATE CONFIDENCE. EXPECT MOSTLY
VFR...ISOLATED MVFR ALONG THE MASS EAST COASTLINE IN RAIN/SNOW
SHOWERS.

TUESDAY NIGHT INTO WEDNESDAY...MODERATE CONFIDENCE. CONDITIONS WILL
BE DETERIORATING AS HEAVY DOWNPOURS...ISO THUNDER AND GUSTY SOUTHERLY
WINDS MOVE INTO THE REGION BY WEDNESDAY. COULD SEE MVFR TO IFR
CONDITIONS IN CIGS AND VSBYS.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /TODAY THROUGH SUNDAY/...HIGH CONFIDENCE.

HIGH PRESSURE ACROSS QUEBEC WILL RESULT IN PERSISTENT NORTHEAST
WINDS ACROSS THE WATERS THROUGH THE WEEKEND.  WIND GUSTS UP TO 20
KNOTS WITH SEAS BETWEEN 2 AND 4 FEET ARE EXPECTED FOR MOST
WATERS...SO NO HEADLINES PLANNED. THERE IS A LOW PROBABILITY THAT A
BRIEF SURGE OF NORTHEAST WIND GUSTS NEAR 25 KNOTS WITH MARGINAL 5
FOOT SEAS COULD AFFECT OUR NORTHERN WATERS LATE TONIGHT INTO SUN
MORNING...BUT NOT CONFIDENT ENOUGH TO ISSUE ANY HEADLINES AT THIS
POINT.

OUTLOOK...SUNDAY NIGHT INTO WEDNESDAY...MODERATE TO HIGH
CONFIDENCE.

SUNDAY INTO MONDAY. CONTINUOUS NORTHEAST FLOW WILL KEEP SEAS CHOPPY.
LINGERING NORTHEAST SWELL MAY BUMP SEAS ABOVE 5FT ESP ACROSS THE
NORTHEASTERN WATERS. SCA MAY BE NEEDED...BUT LOWER CONFIDENCE.

TUESDAY INTO WEDNESDAY...NE WINDS WILL INCREASE...GUSTING TO 30 KT
TUE THEN SHIFT TO SE GUSTING TO 30-35 KT WED...HIGHEST ON THE OUTER
WATERS. SEAS BUILD UP TO 7-11 FT BY WED. GALES WILL BE NEEDED.

&&

.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES WILL OCCUR TUESDAY THROUGH THURSDAY. BREAKING
IT DOWN...ON TUESDAY HIGH TIDE AT BOSTON WILL BE 11.6 FT. THERE WILL
BE ONSHORE FLOW DURING THIS HIGH TIDE ALLOWING FOR MINOR SPLASHOVER.
IF WIND GUSTS INCREASE THEN COULD POSSIBLE SEE MINOR COASTAL
FLOODING.

ON WEDNESDAY...WINDS WILL SWITCH TO A MORE SOUTHEASTERLY FLOW DURING
THE DAY AND INCREASE QUICKLY FROM APPROACHING SYSTEM AND DESCENT
PRESSURE FALLS. WEDNESDAY AFTERNOON HIGH TIDE IN BOSTON IS 11.7 FT
AND WITH ANY STRENGTH ON THE EASTERLY WIND FLOW WILL PUSH THE TIDE
OVER. RIGHT NOW BELIEVE MINOR COASTAL FLOODING IS POSSIBLE ALONG THE
EAST COASTLINE. HOWEVER WEDNESDAY EVENING...THE WIND GOES IN A MORE
SOUTHERLY DIRECTION AND HIGH TIDE IN PROVIDENCE WILL BE 5.2 FT. 925
MB LLJ STRENGTHENS TO 50-60 KTS WHICH COULD PUSH A DESCENT SURGE UP
ALONG THE SOUTH COAST DURING THE TIME OF HIGH TIDE. THINKING THAT
MINOR COASTAL FLOODING COULD OCCUR BUT CANNOT RULE OUT MODERATE
ALONG THE SOUTH COAST...ESP IF LLJ STRENGTHENS EVEN MORE.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...FRANK/DUNTEN
NEAR TERM...FRANK/DUNTEN/RLG
SHORT TERM...FRANK
LONG TERM...DUNTEN
AVIATION...FRANK/DUNTEN
MARINE...FRANK/DUNTEN
TIDES/COASTAL FLOODING...





000
FXUS61 KBOX 201204
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
704 AM EST SAT DEC 20 2014

.SYNOPSIS...
SCATTERED SNOW SHOWERS WILL GRADUALLY OVERSPREAD THE REGION FROM
EAST TO WEST LATER TODAY INTO SUNDAY.  THE EXCEPTION WILL BE THE
IMMEDIATE SOUTHEAST NEW ENGLAND COAST...WHERE IT SHOULD BECOME MILD
ENOUGH FOR SCATTERED RAIN SHOWERS. WEAK LOW PRESSURE WILL PASS SOUTH
OF NEW ENGLAND...BRINGING ANOTHER PERIOD OF PRECIPITATION. A MUCH
STRONGER STORM PASSING WEST OF NEW ENGLAND WILL BRING HEAVY
RAINFALL...GUSTY WINDS AND COASTAL FLOODING CONCERNS TO THE REGION
WEDNESDAY INTO WEDNESDAY EVENING. DRY BUT VERY WINDY CONDITIONS
FOLLOW FOR CHRISTMAS DAY INTO FRIDAY.

&&

.NEAR TERM /UNTIL NOON TODAY/...

700 AM UPDATE...

TREND IN THE FORECAST REMAINS ON TRACK. NORTHEASTERLY FLOW ONSHORE
HAS LEAD TO A FEW FLURRIES ACROSS THE CAPE AND PLYMOUTH COUNTY.
SHOULD BE LOCALIZED TO THIS REGION AS THE FLOW OVER BOSTON AND
TAUNTON ARE NORTHWEST. OTHERWISE CLOUDS ARE SLOWLY STARTING TO
FILL.

PREVIOUS DISCUSSION...

AN APPROACHING SHORTWAVE HAS ALLOWED WINDS JUST OFF THE GROUND TO
BECOME EASTERLY.  THIS WAS ALLOWING LOW CLOUDS TO BACK INTO
SOUTHEAST MA/RI EARLY THIS MORNING.  EXPECT THIS TREND TO CONTINUE
WITH LOW CLOUDS CONTINUING TO GRADUALLY WORK FURTHER WEST...BUT M.
SUNNY SKIES SHOULD PREVAIL THIS MORNING IN NORTHWEST MA.
MEANWHILE...SOME OCEAN EFFECT FLURRIES/LIGHT SNOW SHOWERS MAY
DEVELOP ACROSS PLYMOUTH COUNTY AND ONTO THE CAPE/ISLANDS THIS
MORNING.

&&

.SHORT TERM /NOON TODAY THROUGH 6 PM SUNDAY/...
THIS AFTERNOON AND TONIGHT...

INTERESTING MESOSCALE SETUP AS AN INVERTED TROUGH COMBINES WITH SOME
OCEAN ENHANCEMENT.  APPROACHING UPPER LEVEL SHORTWAVE WILL ALLOW FOR
EASTERLY FLOW JUST OFF THE GROUND.  THIS COMBINED WITH NORTHEAST
SURFACE WINDS WILL ALLOW LOW LEVEL OF THE ATMOSPHERE TO MOISTEN.
SOUNDINGS ACROSS EASTERN NEW ENGLAND BECOME SATURATED ALL THE WAY UP
TO THE -9C LAYER JUST ABOVE 850 MB.  THIS IS FAVORABLE FOR SOME
DECENT SNOWGROWTH...ITS JUST LOWER IN THE ATMOSPHERE THAN WE
TYPICALLY SEE WITH MORE SYNOPTIC SNOW EVENTS.  WHILE THIS IS NOT A
TRUE OCEAN EFFECT EVENT...DELTA T VALUES FROM THE MIXED LAYER TO THE
OCEAN ARE AROUND 15C.  THEREFORE...EXPECT SOME OCEAN ENHANCEMENT.

TIMING:

WHILE FLURRIES/LIGHT SNOW SHOWERS MAY OCCUR ACROSS FAR SOUTHEAST NEW
ENGLAND THIS MORNING.  THE MORE SUBSTANTIAL  PRECIPITATION SHOULD
OVERSPREAD PLYMOUTH COUNTY AS WELL AS THE CAPE AND ISLANDS THIS
AFTERNOON.  GIVEN EASTERLY FLOW JUST OFF THE GROUND...EXPECT SNOW
SHOWERS TO OVERSPREAD MOST OF EASTERN NEW ENGLAND THIS EVENING AS
LOW LEVELS MOISTEN.  IN FACT...SHOULD SEE AT LEAST SOME SCATTERED
SNOW SHOWERS AFFECT EVEN OUR FAR WESTERN ZONES.

PTYPE:

MAINLY SNOW FOR ALL BUT PORTIONS OF COASTAL PLYMOUTH COUNTY AND ONTO
THE CAPE/ISLANDS.  A SUBTLE COASTAL FRONT LOOKS TO SETUP ACROSS
SOUTHEAST COASTAL PLYMOUTH COUNTY.  PTYPE WILL BE SNOW TO THE
NORTHWEST OF THIS REGION...BUT ENOUGH MILD AIR SHOULD COME IN OFF
THE OCEAN FOR A CHANGE TO RAIN SHOWERS SOUTHEAST OF THIS REGION.
NOT EXPECTING THE POSITION OF THIS SUBTLE BOUNDARY TO CHANGE MUCH
THROUGH SUNDAY MORNING.

SNOW ACCUMULATIONS:

WE ARE GENERALLY LOOKING AT A COATING TO 2 INCHES OF SNOW ACROSS
MOST OF THE REGION.  THE MAIN FOCUS FOR 1 TO 2 INCHES WILL BE ACROSS
PORTIONS OF SOUTHEAST MA...AWAY FROM THE SOUTHEAST PLYMOUTH COUNTY
COAST.  ALSO...THE WORCESTER HILLS INTO NORTHWEST RHODE ISLAND MIGHT
BE ANOTHER AREA AS A RESULT OF THE SUBTLE UPSLOPE COMPONENT TO THE
WIND.  YOU CAN ACTUALLY SEE THAT IN SOME OF THE HIGH RESOLUTION
MODEL GUIDANCE.

THERE IS ONE AREA TO WATCH IN PARTICULAR...FROM NORTHWEST PLYMOUTH
COUNTY AND INTO NORFOLK COUNTY BASED ON MESOSCALE MODELS AND PATTERN
RECOGNITION.  WOULD NOT BE SURPRISED TO SEE VERY LOCALIZED 3 TO 4
INCH SNOW AMOUNTS...GIVEN SOME OCEAN ENHANCEMENT AND A LITTLE FOCUS
ON THE COASTAL FRONT.  WILL TRY TO HIGHLIGHT THIS AREA IN OUR
SNOWFALL AND PROBABILISTIC  GRAPHICS.

SUNDAY...

SCATTERED SNOW SHOWERS WILL CONTINUE DURING THE MORNING WITH MOIST
EASTERLY FLOW IN THE LOW LEVELS. AGAIN...PTYPE WILL BE SNOW EXCEPT
ACROSS SOUTHEAST PLYMOUTH COUNTY/CAPE AND ISLANDS WHERE BOUNDARY
LAYER WILL PROBABLY BE WARM ENOUGH FOR RAIN SHOWERS.  WHILE SOME
LIGHT PRECIPITATION MAY LINGER INTO SUNDAY AFTERNOON...EXPECT A
DECREASE IN AREAL COVERAGE THROUGH THE AFTERNOON AS LOW LEVEL LIFT
WEAKENS.  IT WILL REMAIN CLOUDY THOUGH WITH TEMPS IN THE 30S.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
HIGHLIGHTS...

* INVERTED TROUGH WILL BRING RAIN/SNOW SHOWERS TO THE MASS EAST
  COASTLINE MONDAY INTO TUES MORNING.
* WEAK WAVE OF LOW PRESSURE MON NIGHT/TUESDAY COULD BRING WINTRY
  MIX TO INTERIOR
* ANOMALOUS SYSTEM ACROSS THE GREAT LAKES WILL BRING HEAVY
  RAIN...GUSTY WINDS AND COASTAL FLOODING CONCERNS AROUND CHRISTMAS
  EVE

OVERVIEW...

OVERALL 00Z GUIDANCE IS IN AGREEMENT SYNOPTICALLY WITH ISSUES ON
TIMING AND SMALLER SCALE FEATURES. IT REMAINS EVIDENT THAT AN
AMPLIFIED MID-UPPER LEVEL TROUGH AND PCPN FOCUSING LEAD SURFACE
LOW/FRONTAL SYSTEM WILL STEADILY PROGRESS TO THE EAST-CENTRAL U.S.
TUE AS EMBEDDED IMPULSES DIG TO THE LEE OF AN AMPLIFIED ERN
PACIFIC/WEST COAST RIDGE ALOFT. THE SUPPORTING AND INCREASINGLY
NEGATIVE-TILT TROUGH ALOFT WORKS OVER THE ERN US AND OUT THROUGH THE
NERN STATES INTO DAYS 4/5 WED/THU.  MODELS/ENSEMBLES HAVE BEEN
FAIRLY CONSISTENT ON THIS AMPLIFIED PATTERN AND THE MOST RECENT
GEFS/ECMWF ENSEMBLE GUIDANCE SHOW GOOD CORRELATION TO NEXT THURSDAY.

HIGH PRESSURE AND UPPER LEVEL RIDGE OVER THE REGION WILL BEGIN TO
EXIT BY MONDAY. AT THE SURFACE APPEARS ANOTHER INVERTED
TROUGH/ONSHORE FLOW WILL YIELD TO PRECIP ALONG THE MASS COASTLINE ON
MONDAY. ASIDE FROM THIS QUICK MESOSCALE EVENT THE MAIN FOCUS IS ON
THE LONGWAVE DIGGING TROUGH OVER THE CENTRAL CONUS WHICH WILL PUSH A
FEW SHORTWAVES THROUGH THE FLOW. FIRST ONE DEVELOPS A WEAK WAVE
MOVING TOWARDS THE REGION LATE MONDAY INTO TUESDAY. THERE IS STILL
SOME UNCERTAINTY WITH THE LOCATION/STRENGTH OF THIS SYSTEM BUT
APPEARS THAT THERE IS THE POSSIBILITY OF A SNOW/WINTRY MIX IN THE
INTERIOR. AS THIS SYSTEM DEPARTS AN ANOMALOUS LOW OVER THE GREAT
LAKES WILL DEVELOP A SECONDARY LOW JUST WEST OF SOUTHERN NEW ENGLAND
     PER ENSEMBLE GUIDANCE. STILL A SOME SPREAD BUT IF THIS DOUBLE LOW
DOES DEVELOP THEN THE RAIN AND WIND ASPECT OF THE SYSTEM
INCREASES...DETAILS BELOW. STILL NEED TO WORK OUT MINOR DETAILS WITH
THIS PARTICULAR SYSTEM BUT WITH 3 TO 4 STANDARD DEVIATIONS AWAY AND
GENERAL MODEL AGREEMENT HAVE HIGH CONFIDENCE THIS SYSTEM WILL IMPACT
SOUTHERN NEW ENGLAND.

DETAILS...

SUNDAY NIGHT INTO TUESDAY...MODERATE CONFIDENCE.

HIGH PRESSURE AND UPPER LEVEL RIDGE WILL BEGIN TO MOVE OFFSHORE AS
DIGGING TROUGH BEGINS TO SET-UP OVER THE CENTRAL CONUS. APPEARS
ANOTHER MESO-SCALE INVERTED TROUGH WILL SET UP ON MONDAY AND LAST
INTO EARLY TUESDAY MORNING. GUIDANCE SHOWS THAT RAIN/SNOW SHOWERS
WILL DEVELOP ALONG THE MASS EAST COASTLINE THANKS TO ONSHORE
EASTERLY FLOW. APPEARS THE COLUMN WILL SATURATE PER BUFKIT SOUNDINGS
AND SOUTHERLY FLOW ALOFT. BOTH THE NAM AND GFS SHOW QPF MAKING IT
ONSHORE DURING THIS TIME FRAME. HOWEVER THE EC IS SLIGHTLY SLOWER
AND KEEP THE BULK OF THE PRECIP JUST OFFSHORE. ADD A CHANCE OF POPS
DUE TO THE NAM/GFS MODEL CONTINUITY.

BY LATE MONDAY NIGHT INTO TUESDAY A SOUTHERN BRANCH STORM SYSTEM
FORMS ALONG THE SE COAST AND TAKES A TRACK OFF THE MID ATLANTIC
COAST. THIS SYSTEM GETS CAUGHT UP WITH THE OVERALL LARGE SCALE
AMPLIFICATION OF THE UPPER AIR PATTERN. THERE IS DECENT WARM
ADVECTION WITH COLD AIR DAMMING ACROSS THE INTERIOR. BIGGEST
QUESTION WILL BE IS THERE ENOUGH MOISTURE FOR PRECIP DURING THIS
TIME FRAME. IF PRECIP OVERRUNS THEN COULD SEE FREEZING RAIN/DRIZZLE
ACROSS THE INTERIOR LATE MONDAY INTO TUESDAY MORNING. DURING THE DAY
ON TUESDAY...GOOD AMOUNT OF WARM AIR WILL PUSH SURFACE TEMPS ABOVE
FREEZING ALLOWING FOR ANY PRECIP TO BE MORE OF THE LIQUID VARIETY
AHEAD OF THE CHRISTMAS EVE STORM. HOWEVER GUIDANCE IS ALWAYS TOO
FAST IN SCOURING TEMPS OUT ESP ACROSS THE CT VALLEY SO WE WILL NEED
TO MONITOR THIS CLOSELY...ESP DUE TO LIGHT WINDS AND THE HIGH IN
EASTERN CANADA.

WE COULD ALSO SEE SOME MINOR COASTAL FLOODING CONCERNS ON TUESDAY. SEE
BELOW FOR MORE DETAILS.

WEDNESDAY INTO THURSDAY...HIGH CONFIDENCE IN SYSTEM LOW CONFIDENCE
ON DETAILS.

STRONG ANOMALOUS SYSTEM WILL STRENGTHEN OVER THE GREAT
LAKES...DEVELOPING A POTENTIAL SECONDARY SURFACE LOW JUST WEST OF
SOUTHERN NEW ENGLAND. STILL A LOT OF DETAILS TO WORK OUT AS THIS
SYSTEM IS STILL 5 DAYS AWAY...HOWEVER ENSEMBLES CONTINUE TO SHOW
STRONG AGREEMENT SO HAVE INCREASING CONFIDENCE THAT A POTENT STORM
WILL OCCUR. LATEST 00Z GUIDANCE SHOWS THAT MOST PRECIP WILL BE
LIQUID WITH A DEEP SUBTROPICAL CONNECTION BACK ACROSS THE GULF OF
MEXICO...PW ANOMALIES FORECAST TO RISE BETWEEN +3 TO +4. CURRENT
PWATS ARE PROGGED ABOVE 1.6 INCHES SO HAVE CONTINUED THE CATEGORICAL
POPS. TEMPERATURES WILL BE WELL ABOVE AVERAGE...IN FACT WE MAY BE
CLOSE AT BREAKING RECORD HIGH TEMPS IF TEMPS WARM TO 60F OR ABOVE ON
CHRISTMAS EVE.  AS THE SYSTEM WRAPS UP INTO CANADA...COLD AIR
ADVECTION SHOULD CIRCULATE AROUND AND BEGIN A TRANSITION FROM
SOUTHWEST TO NORTHEAST IN TURNING P-TYPE TO SNOW. HOWEVER LATEST
GUIDANCE DOES SHOW A QUICK MOVING DRY SLOT SO SNOWFALL WILL STRUGGLE
DUE TO LACK OF MOISTURE.

THIS SYSTEM IS QUITE POTENT SO WE WILL NEED TO WATCH FOR POTENTIAL
HAZARDS. CURRENTLY THINK THAT WE COULD POSSIBLE URBAN FLOODING
ISSUES AS MODELS PROGGED WELL OVER 1.5 INCHES OF QPF. LATEST EC EVEN
SHOWS 2.5 INCHES OF QPF IS POSSIBLE. THE GEFS SHOW A MOISTURE FLUX
AT 850 MB BEING 4 TO 5 STANDARD DEVIATIONS AWAY...AND WITH THE
TROPICAL CONNECTION AND STRONG SOUTHERLY FLOW COULD SEE HIGHER
AMOUNTS DUE TO TOPOGRAPHY ENHANCEMENTS. RAIN FALL RECORDS MAY FALL
IF EVERYTHING FALLS INTO PLACE.

ALSO BELIEVE THAT WE MAY SEE SOME WIND ISSUES WITH THIS SYSTEM.
GUIDANCE RIGHT NOW IS SHOWING A 45 TO 55 KT JET AT 925 MB...HOWEVER
IT WILL BE HARD TO BREAK THE INVERSION WITH THE SOUTHERLY FLOW.
RIGHT NOW BELIEVE THAT WIND ADVISORIES MAY BE NEEDED BUT IF THIS
SYSTEM STRENGTHEN EVEN MORE SO A STRONGER JET IS POSSIBLE.

CONTINUED THE MENTIONED OF ISOLATED THUNDER IN THE FORECAST PER PREV
FORECASTER SUGGESTION. BELIEVE IT COULD BE POSSIBLE AS SOUTHERN NEW
ENGLAND WILL BE IN THE WARM SECTOR...WITH THE ANOMALOUS JET AND
SHOWALTERS CLOSE TO ZERO.

FRIDAY...LOW CONFIDENCE.

ONCE UPPER LEVEL LOW MOVES INTO SOUTHERN CANADA...EXPECT A RATHER
FAST UPPER W FLOW IN PLACE. MAY SEE LEFTOVER SNOW SHOWERS BUT TEMPS
WILL FALL BACK CLOSE TO SEASONAL NORMS.

&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /THROUGH SUNDAY/...

700 AM UPDATE...

TODAY...MODERATE CONFIDENCE.  MVFR CIGS WILL CONTINUE TO OVERSPREAD
EASTERN NEW ENGLAND THIS MORNING AND EVENTUALLY INTO THE INTERIOR
THIS AFTERNOON.  SCATTERED PRECIPITATION WILL OVERSPREAD
SOUTHEAST MA/CAPE/ISLANDS THIS AFTERNOON.  PTYPE MAINLY SNOW SHOWERS
NORTHWEST OF THE SOUTHEAST PLYMOUTH COUNTY COAST AND RAIN SHOWERS
SOUTHEAST OF THAT REGION. LOCALIZED IFR CONDITIONS POSSIBLE JUST
INLAND FROM THE SOUTHEAST NEW ENGLAND COAST...WHERE PTYPE IS SNOW.

TONIGHT AND SUNDAY...MODERATE CONFIDENCE.  MVFR CONDITIONS DOMINATE
IN LOWER CLOUDS AND SCATTERED PRECIPITATION.  LOCALIZED IFR
CONDITIONS POSSIBLE WITH THE BEST CHANCE IN SNOW SHOWERS.
PRECIPITATION AFFECTS MAINLY EASTERN NEW ENGLAND BUT STILL SOME
SCATTERED ACTIVITY ACROSS WESTERN NEW ENGLAND. PTYPE MAINLY SNOW
SHOWERS NORTHWEST OF THE SOUTHEAST PLYMOUTH COUNTY COAST...WITH RAIN
SHOWERS SOUTHEAST OF THAT REGION.

KBOS TERMINAL...MODERATE CONFIDENCE IN TAF.  SNOW SHOWERS MAY ARRIVE
TOWARDS 00Z THIS EVENING.

KBDL TERMINAL...MODERATE CONFIDENCE IN TAF.

OUTLOOK...SUNDAY NIGHT THROUGH WEDNESDAY...

MONDAY INTO TUESDAY...MODERATE CONFIDENCE. EXPECT MOSTLY
VFR...ISOLATED MVFR ALONG THE MASS EAST COASTLINE IN RAIN/SNOW
SHOWERS.

TUESDAY NIGHT INTO WEDNESDAY...MODERATE CONFIDENCE. CONDITIONS WILL
BE DETERIORATING AS HEAVY DOWNPOURS...ISO THUNDER AND GUSTY SOUTHERLY
WINDS MOVE INTO THE REGION BY WEDNESDAY. COULD SEE MVFR TO IFR
CONDITIONS IN CIGS AND VSBYS.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /TODAY THROUGH SUNDAY/...HIGH CONFIDENCE.

HIGH PRESSURE ACROSS QUEBEC WILL RESULT IN PERSISTENT NORTHEAST
WINDS ACROSS THE WATERS THROUGH THE WEEKEND.  WIND GUSTS UP TO 20
KNOTS WITH SEAS BETWEEN 2 AND 4 FEET ARE EXPECTED FOR MOST
WATERS...SO NO HEADLINES PLANNED. THERE IS A LOW PROBABILITY THAT A
BRIEF SURGE OF NORTHEAST WIND GUSTS NEAR 25 KNOTS WITH MARGINAL 5
FOOT SEAS COULD AFFECT OUR NORTHERN WATERS LATE TONIGHT INTO SUN
MORNING...BUT NOT CONFIDENT ENOUGH TO ISSUE ANY HEADLINES AT THIS
POINT.

OUTLOOK...SUNDAY NIGHT INTO WEDNESDAY...MODERATE TO HIGH
CONFIDENCE.

SUNDAY INTO MONDAY. CONTINUOUS NORTHEAST FLOW WILL KEEP SEAS CHOPPY.
LINGERING NORTHEAST SWELL MAY BUMP SEAS ABOVE 5FT ESP ACROSS THE
NORTHEASTERN WATERS. SCA MAY BE NEEDED...BUT LOWER CONFIDENCE.

TUESDAY INTO WEDNESDAY...NE WINDS WILL INCREASE...GUSTING TO 30 KT
TUE THEN SHIFT TO SE GUSTING TO 30-35 KT WED...HIGHEST ON THE OUTER
WATERS. SEAS BUILD UP TO 7-11 FT BY WED. GALES WILL BE NEEDED.

&&

.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES WILL OCCUR TUESDAY THROUGH THURSDAY. BREAKING
IT DOWN...ON TUESDAY HIGH TIDE AT BOSTON WILL BE 11.6 FT. THERE WILL
BE ONSHORE FLOW DURING THIS HIGH TIDE ALLOWING FOR MINOR SPLASHOVER.
IF WIND GUSTS INCREASE THEN COULD POSSIBLE SEE MINOR COASTAL
FLOODING.

ON WEDNESDAY...WINDS WILL SWITCH TO A MORE SOUTHEASTERLY FLOW DURING
THE DAY AND INCREASE QUICKLY FROM APPROACHING SYSTEM AND DESCENT
PRESSURE FALLS. WEDNESDAY AFTERNOON HIGH TIDE IN BOSTON IS 11.7 FT
AND WITH ANY STRENGTH ON THE EASTERLY WIND FLOW WILL PUSH THE TIDE
OVER. RIGHT NOW BELIEVE MINOR COASTAL FLOODING IS POSSIBLE ALONG THE
EAST COASTLINE. HOWEVER WEDNESDAY EVENING...THE WIND GOES IN A MORE
SOUTHERLY DIRECTION AND HIGH TIDE IN PROVIDENCE WILL BE 5.2 FT. 925
MB LLJ STRENGTHENS TO 50-60 KTS WHICH COULD PUSH A DESCENT SURGE UP
ALONG THE SOUTH COAST DURING THE TIME OF HIGH TIDE. THINKING THAT
MINOR COASTAL FLOODING COULD OCCUR BUT CANNOT RULE OUT MODERATE
ALONG THE SOUTH COAST...ESP IF LLJ STRENGTHENS EVEN MORE.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...FRANK/DUNTEN
NEAR TERM...FRANK/DUNTEN
SHORT TERM...FRANK
LONG TERM...DUNTEN
AVIATION...FRANK/DUNTEN
MARINE...FRANK/DUNTEN
TIDES/COASTAL FLOODING...




000
FXUS61 KBOX 201204
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
704 AM EST SAT DEC 20 2014

.SYNOPSIS...
SCATTERED SNOW SHOWERS WILL GRADUALLY OVERSPREAD THE REGION FROM
EAST TO WEST LATER TODAY INTO SUNDAY.  THE EXCEPTION WILL BE THE
IMMEDIATE SOUTHEAST NEW ENGLAND COAST...WHERE IT SHOULD BECOME MILD
ENOUGH FOR SCATTERED RAIN SHOWERS. WEAK LOW PRESSURE WILL PASS SOUTH
OF NEW ENGLAND...BRINGING ANOTHER PERIOD OF PRECIPITATION. A MUCH
STRONGER STORM PASSING WEST OF NEW ENGLAND WILL BRING HEAVY
RAINFALL...GUSTY WINDS AND COASTAL FLOODING CONCERNS TO THE REGION
WEDNESDAY INTO WEDNESDAY EVENING. DRY BUT VERY WINDY CONDITIONS
FOLLOW FOR CHRISTMAS DAY INTO FRIDAY.

&&

.NEAR TERM /UNTIL NOON TODAY/...

700 AM UPDATE...

TREND IN THE FORECAST REMAINS ON TRACK. NORTHEASTERLY FLOW ONSHORE
HAS LEAD TO A FEW FLURRIES ACROSS THE CAPE AND PLYMOUTH COUNTY.
SHOULD BE LOCALIZED TO THIS REGION AS THE FLOW OVER BOSTON AND
TAUNTON ARE NORTHWEST. OTHERWISE CLOUDS ARE SLOWLY STARTING TO
FILL.

PREVIOUS DISCUSSION...

AN APPROACHING SHORTWAVE HAS ALLOWED WINDS JUST OFF THE GROUND TO
BECOME EASTERLY.  THIS WAS ALLOWING LOW CLOUDS TO BACK INTO
SOUTHEAST MA/RI EARLY THIS MORNING.  EXPECT THIS TREND TO CONTINUE
WITH LOW CLOUDS CONTINUING TO GRADUALLY WORK FURTHER WEST...BUT M.
SUNNY SKIES SHOULD PREVAIL THIS MORNING IN NORTHWEST MA.
MEANWHILE...SOME OCEAN EFFECT FLURRIES/LIGHT SNOW SHOWERS MAY
DEVELOP ACROSS PLYMOUTH COUNTY AND ONTO THE CAPE/ISLANDS THIS
MORNING.

&&

.SHORT TERM /NOON TODAY THROUGH 6 PM SUNDAY/...
THIS AFTERNOON AND TONIGHT...

INTERESTING MESOSCALE SETUP AS AN INVERTED TROUGH COMBINES WITH SOME
OCEAN ENHANCEMENT.  APPROACHING UPPER LEVEL SHORTWAVE WILL ALLOW FOR
EASTERLY FLOW JUST OFF THE GROUND.  THIS COMBINED WITH NORTHEAST
SURFACE WINDS WILL ALLOW LOW LEVEL OF THE ATMOSPHERE TO MOISTEN.
SOUNDINGS ACROSS EASTERN NEW ENGLAND BECOME SATURATED ALL THE WAY UP
TO THE -9C LAYER JUST ABOVE 850 MB.  THIS IS FAVORABLE FOR SOME
DECENT SNOWGROWTH...ITS JUST LOWER IN THE ATMOSPHERE THAN WE
TYPICALLY SEE WITH MORE SYNOPTIC SNOW EVENTS.  WHILE THIS IS NOT A
TRUE OCEAN EFFECT EVENT...DELTA T VALUES FROM THE MIXED LAYER TO THE
OCEAN ARE AROUND 15C.  THEREFORE...EXPECT SOME OCEAN ENHANCEMENT.

TIMING:

WHILE FLURRIES/LIGHT SNOW SHOWERS MAY OCCUR ACROSS FAR SOUTHEAST NEW
ENGLAND THIS MORNING.  THE MORE SUBSTANTIAL  PRECIPITATION SHOULD
OVERSPREAD PLYMOUTH COUNTY AS WELL AS THE CAPE AND ISLANDS THIS
AFTERNOON.  GIVEN EASTERLY FLOW JUST OFF THE GROUND...EXPECT SNOW
SHOWERS TO OVERSPREAD MOST OF EASTERN NEW ENGLAND THIS EVENING AS
LOW LEVELS MOISTEN.  IN FACT...SHOULD SEE AT LEAST SOME SCATTERED
SNOW SHOWERS AFFECT EVEN OUR FAR WESTERN ZONES.

PTYPE:

MAINLY SNOW FOR ALL BUT PORTIONS OF COASTAL PLYMOUTH COUNTY AND ONTO
THE CAPE/ISLANDS.  A SUBTLE COASTAL FRONT LOOKS TO SETUP ACROSS
SOUTHEAST COASTAL PLYMOUTH COUNTY.  PTYPE WILL BE SNOW TO THE
NORTHWEST OF THIS REGION...BUT ENOUGH MILD AIR SHOULD COME IN OFF
THE OCEAN FOR A CHANGE TO RAIN SHOWERS SOUTHEAST OF THIS REGION.
NOT EXPECTING THE POSITION OF THIS SUBTLE BOUNDARY TO CHANGE MUCH
THROUGH SUNDAY MORNING.

SNOW ACCUMULATIONS:

WE ARE GENERALLY LOOKING AT A COATING TO 2 INCHES OF SNOW ACROSS
MOST OF THE REGION.  THE MAIN FOCUS FOR 1 TO 2 INCHES WILL BE ACROSS
PORTIONS OF SOUTHEAST MA...AWAY FROM THE SOUTHEAST PLYMOUTH COUNTY
COAST.  ALSO...THE WORCESTER HILLS INTO NORTHWEST RHODE ISLAND MIGHT
BE ANOTHER AREA AS A RESULT OF THE SUBTLE UPSLOPE COMPONENT TO THE
WIND.  YOU CAN ACTUALLY SEE THAT IN SOME OF THE HIGH RESOLUTION
MODEL GUIDANCE.

THERE IS ONE AREA TO WATCH IN PARTICULAR...FROM NORTHWEST PLYMOUTH
COUNTY AND INTO NORFOLK COUNTY BASED ON MESOSCALE MODELS AND PATTERN
RECOGNITION.  WOULD NOT BE SURPRISED TO SEE VERY LOCALIZED 3 TO 4
INCH SNOW AMOUNTS...GIVEN SOME OCEAN ENHANCEMENT AND A LITTLE FOCUS
ON THE COASTAL FRONT.  WILL TRY TO HIGHLIGHT THIS AREA IN OUR
SNOWFALL AND PROBABILISTIC  GRAPHICS.

SUNDAY...

SCATTERED SNOW SHOWERS WILL CONTINUE DURING THE MORNING WITH MOIST
EASTERLY FLOW IN THE LOW LEVELS. AGAIN...PTYPE WILL BE SNOW EXCEPT
ACROSS SOUTHEAST PLYMOUTH COUNTY/CAPE AND ISLANDS WHERE BOUNDARY
LAYER WILL PROBABLY BE WARM ENOUGH FOR RAIN SHOWERS.  WHILE SOME
LIGHT PRECIPITATION MAY LINGER INTO SUNDAY AFTERNOON...EXPECT A
DECREASE IN AREAL COVERAGE THROUGH THE AFTERNOON AS LOW LEVEL LIFT
WEAKENS.  IT WILL REMAIN CLOUDY THOUGH WITH TEMPS IN THE 30S.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
HIGHLIGHTS...

* INVERTED TROUGH WILL BRING RAIN/SNOW SHOWERS TO THE MASS EAST
  COASTLINE MONDAY INTO TUES MORNING.
* WEAK WAVE OF LOW PRESSURE MON NIGHT/TUESDAY COULD BRING WINTRY
  MIX TO INTERIOR
* ANOMALOUS SYSTEM ACROSS THE GREAT LAKES WILL BRING HEAVY
  RAIN...GUSTY WINDS AND COASTAL FLOODING CONCERNS AROUND CHRISTMAS
  EVE

OVERVIEW...

OVERALL 00Z GUIDANCE IS IN AGREEMENT SYNOPTICALLY WITH ISSUES ON
TIMING AND SMALLER SCALE FEATURES. IT REMAINS EVIDENT THAT AN
AMPLIFIED MID-UPPER LEVEL TROUGH AND PCPN FOCUSING LEAD SURFACE
LOW/FRONTAL SYSTEM WILL STEADILY PROGRESS TO THE EAST-CENTRAL U.S.
TUE AS EMBEDDED IMPULSES DIG TO THE LEE OF AN AMPLIFIED ERN
PACIFIC/WEST COAST RIDGE ALOFT. THE SUPPORTING AND INCREASINGLY
NEGATIVE-TILT TROUGH ALOFT WORKS OVER THE ERN US AND OUT THROUGH THE
NERN STATES INTO DAYS 4/5 WED/THU.  MODELS/ENSEMBLES HAVE BEEN
FAIRLY CONSISTENT ON THIS AMPLIFIED PATTERN AND THE MOST RECENT
GEFS/ECMWF ENSEMBLE GUIDANCE SHOW GOOD CORRELATION TO NEXT THURSDAY.

HIGH PRESSURE AND UPPER LEVEL RIDGE OVER THE REGION WILL BEGIN TO
EXIT BY MONDAY. AT THE SURFACE APPEARS ANOTHER INVERTED
TROUGH/ONSHORE FLOW WILL YIELD TO PRECIP ALONG THE MASS COASTLINE ON
MONDAY. ASIDE FROM THIS QUICK MESOSCALE EVENT THE MAIN FOCUS IS ON
THE LONGWAVE DIGGING TROUGH OVER THE CENTRAL CONUS WHICH WILL PUSH A
FEW SHORTWAVES THROUGH THE FLOW. FIRST ONE DEVELOPS A WEAK WAVE
MOVING TOWARDS THE REGION LATE MONDAY INTO TUESDAY. THERE IS STILL
SOME UNCERTAINTY WITH THE LOCATION/STRENGTH OF THIS SYSTEM BUT
APPEARS THAT THERE IS THE POSSIBILITY OF A SNOW/WINTRY MIX IN THE
INTERIOR. AS THIS SYSTEM DEPARTS AN ANOMALOUS LOW OVER THE GREAT
LAKES WILL DEVELOP A SECONDARY LOW JUST WEST OF SOUTHERN NEW ENGLAND
     PER ENSEMBLE GUIDANCE. STILL A SOME SPREAD BUT IF THIS DOUBLE LOW
DOES DEVELOP THEN THE RAIN AND WIND ASPECT OF THE SYSTEM
INCREASES...DETAILS BELOW. STILL NEED TO WORK OUT MINOR DETAILS WITH
THIS PARTICULAR SYSTEM BUT WITH 3 TO 4 STANDARD DEVIATIONS AWAY AND
GENERAL MODEL AGREEMENT HAVE HIGH CONFIDENCE THIS SYSTEM WILL IMPACT
SOUTHERN NEW ENGLAND.

DETAILS...

SUNDAY NIGHT INTO TUESDAY...MODERATE CONFIDENCE.

HIGH PRESSURE AND UPPER LEVEL RIDGE WILL BEGIN TO MOVE OFFSHORE AS
DIGGING TROUGH BEGINS TO SET-UP OVER THE CENTRAL CONUS. APPEARS
ANOTHER MESO-SCALE INVERTED TROUGH WILL SET UP ON MONDAY AND LAST
INTO EARLY TUESDAY MORNING. GUIDANCE SHOWS THAT RAIN/SNOW SHOWERS
WILL DEVELOP ALONG THE MASS EAST COASTLINE THANKS TO ONSHORE
EASTERLY FLOW. APPEARS THE COLUMN WILL SATURATE PER BUFKIT SOUNDINGS
AND SOUTHERLY FLOW ALOFT. BOTH THE NAM AND GFS SHOW QPF MAKING IT
ONSHORE DURING THIS TIME FRAME. HOWEVER THE EC IS SLIGHTLY SLOWER
AND KEEP THE BULK OF THE PRECIP JUST OFFSHORE. ADD A CHANCE OF POPS
DUE TO THE NAM/GFS MODEL CONTINUITY.

BY LATE MONDAY NIGHT INTO TUESDAY A SOUTHERN BRANCH STORM SYSTEM
FORMS ALONG THE SE COAST AND TAKES A TRACK OFF THE MID ATLANTIC
COAST. THIS SYSTEM GETS CAUGHT UP WITH THE OVERALL LARGE SCALE
AMPLIFICATION OF THE UPPER AIR PATTERN. THERE IS DECENT WARM
ADVECTION WITH COLD AIR DAMMING ACROSS THE INTERIOR. BIGGEST
QUESTION WILL BE IS THERE ENOUGH MOISTURE FOR PRECIP DURING THIS
TIME FRAME. IF PRECIP OVERRUNS THEN COULD SEE FREEZING RAIN/DRIZZLE
ACROSS THE INTERIOR LATE MONDAY INTO TUESDAY MORNING. DURING THE DAY
ON TUESDAY...GOOD AMOUNT OF WARM AIR WILL PUSH SURFACE TEMPS ABOVE
FREEZING ALLOWING FOR ANY PRECIP TO BE MORE OF THE LIQUID VARIETY
AHEAD OF THE CHRISTMAS EVE STORM. HOWEVER GUIDANCE IS ALWAYS TOO
FAST IN SCOURING TEMPS OUT ESP ACROSS THE CT VALLEY SO WE WILL NEED
TO MONITOR THIS CLOSELY...ESP DUE TO LIGHT WINDS AND THE HIGH IN
EASTERN CANADA.

WE COULD ALSO SEE SOME MINOR COASTAL FLOODING CONCERNS ON TUESDAY. SEE
BELOW FOR MORE DETAILS.

WEDNESDAY INTO THURSDAY...HIGH CONFIDENCE IN SYSTEM LOW CONFIDENCE
ON DETAILS.

STRONG ANOMALOUS SYSTEM WILL STRENGTHEN OVER THE GREAT
LAKES...DEVELOPING A POTENTIAL SECONDARY SURFACE LOW JUST WEST OF
SOUTHERN NEW ENGLAND. STILL A LOT OF DETAILS TO WORK OUT AS THIS
SYSTEM IS STILL 5 DAYS AWAY...HOWEVER ENSEMBLES CONTINUE TO SHOW
STRONG AGREEMENT SO HAVE INCREASING CONFIDENCE THAT A POTENT STORM
WILL OCCUR. LATEST 00Z GUIDANCE SHOWS THAT MOST PRECIP WILL BE
LIQUID WITH A DEEP SUBTROPICAL CONNECTION BACK ACROSS THE GULF OF
MEXICO...PW ANOMALIES FORECAST TO RISE BETWEEN +3 TO +4. CURRENT
PWATS ARE PROGGED ABOVE 1.6 INCHES SO HAVE CONTINUED THE CATEGORICAL
POPS. TEMPERATURES WILL BE WELL ABOVE AVERAGE...IN FACT WE MAY BE
CLOSE AT BREAKING RECORD HIGH TEMPS IF TEMPS WARM TO 60F OR ABOVE ON
CHRISTMAS EVE.  AS THE SYSTEM WRAPS UP INTO CANADA...COLD AIR
ADVECTION SHOULD CIRCULATE AROUND AND BEGIN A TRANSITION FROM
SOUTHWEST TO NORTHEAST IN TURNING P-TYPE TO SNOW. HOWEVER LATEST
GUIDANCE DOES SHOW A QUICK MOVING DRY SLOT SO SNOWFALL WILL STRUGGLE
DUE TO LACK OF MOISTURE.

THIS SYSTEM IS QUITE POTENT SO WE WILL NEED TO WATCH FOR POTENTIAL
HAZARDS. CURRENTLY THINK THAT WE COULD POSSIBLE URBAN FLOODING
ISSUES AS MODELS PROGGED WELL OVER 1.5 INCHES OF QPF. LATEST EC EVEN
SHOWS 2.5 INCHES OF QPF IS POSSIBLE. THE GEFS SHOW A MOISTURE FLUX
AT 850 MB BEING 4 TO 5 STANDARD DEVIATIONS AWAY...AND WITH THE
TROPICAL CONNECTION AND STRONG SOUTHERLY FLOW COULD SEE HIGHER
AMOUNTS DUE TO TOPOGRAPHY ENHANCEMENTS. RAIN FALL RECORDS MAY FALL
IF EVERYTHING FALLS INTO PLACE.

ALSO BELIEVE THAT WE MAY SEE SOME WIND ISSUES WITH THIS SYSTEM.
GUIDANCE RIGHT NOW IS SHOWING A 45 TO 55 KT JET AT 925 MB...HOWEVER
IT WILL BE HARD TO BREAK THE INVERSION WITH THE SOUTHERLY FLOW.
RIGHT NOW BELIEVE THAT WIND ADVISORIES MAY BE NEEDED BUT IF THIS
SYSTEM STRENGTHEN EVEN MORE SO A STRONGER JET IS POSSIBLE.

CONTINUED THE MENTIONED OF ISOLATED THUNDER IN THE FORECAST PER PREV
FORECASTER SUGGESTION. BELIEVE IT COULD BE POSSIBLE AS SOUTHERN NEW
ENGLAND WILL BE IN THE WARM SECTOR...WITH THE ANOMALOUS JET AND
SHOWALTERS CLOSE TO ZERO.

FRIDAY...LOW CONFIDENCE.

ONCE UPPER LEVEL LOW MOVES INTO SOUTHERN CANADA...EXPECT A RATHER
FAST UPPER W FLOW IN PLACE. MAY SEE LEFTOVER SNOW SHOWERS BUT TEMPS
WILL FALL BACK CLOSE TO SEASONAL NORMS.

&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /THROUGH SUNDAY/...

700 AM UPDATE...

TODAY...MODERATE CONFIDENCE.  MVFR CIGS WILL CONTINUE TO OVERSPREAD
EASTERN NEW ENGLAND THIS MORNING AND EVENTUALLY INTO THE INTERIOR
THIS AFTERNOON.  SCATTERED PRECIPITATION WILL OVERSPREAD
SOUTHEAST MA/CAPE/ISLANDS THIS AFTERNOON.  PTYPE MAINLY SNOW SHOWERS
NORTHWEST OF THE SOUTHEAST PLYMOUTH COUNTY COAST AND RAIN SHOWERS
SOUTHEAST OF THAT REGION. LOCALIZED IFR CONDITIONS POSSIBLE JUST
INLAND FROM THE SOUTHEAST NEW ENGLAND COAST...WHERE PTYPE IS SNOW.

TONIGHT AND SUNDAY...MODERATE CONFIDENCE.  MVFR CONDITIONS DOMINATE
IN LOWER CLOUDS AND SCATTERED PRECIPITATION.  LOCALIZED IFR
CONDITIONS POSSIBLE WITH THE BEST CHANCE IN SNOW SHOWERS.
PRECIPITATION AFFECTS MAINLY EASTERN NEW ENGLAND BUT STILL SOME
SCATTERED ACTIVITY ACROSS WESTERN NEW ENGLAND. PTYPE MAINLY SNOW
SHOWERS NORTHWEST OF THE SOUTHEAST PLYMOUTH COUNTY COAST...WITH RAIN
SHOWERS SOUTHEAST OF THAT REGION.

KBOS TERMINAL...MODERATE CONFIDENCE IN TAF.  SNOW SHOWERS MAY ARRIVE
TOWARDS 00Z THIS EVENING.

KBDL TERMINAL...MODERATE CONFIDENCE IN TAF.

OUTLOOK...SUNDAY NIGHT THROUGH WEDNESDAY...

MONDAY INTO TUESDAY...MODERATE CONFIDENCE. EXPECT MOSTLY
VFR...ISOLATED MVFR ALONG THE MASS EAST COASTLINE IN RAIN/SNOW
SHOWERS.

TUESDAY NIGHT INTO WEDNESDAY...MODERATE CONFIDENCE. CONDITIONS WILL
BE DETERIORATING AS HEAVY DOWNPOURS...ISO THUNDER AND GUSTY SOUTHERLY
WINDS MOVE INTO THE REGION BY WEDNESDAY. COULD SEE MVFR TO IFR
CONDITIONS IN CIGS AND VSBYS.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /TODAY THROUGH SUNDAY/...HIGH CONFIDENCE.

HIGH PRESSURE ACROSS QUEBEC WILL RESULT IN PERSISTENT NORTHEAST
WINDS ACROSS THE WATERS THROUGH THE WEEKEND.  WIND GUSTS UP TO 20
KNOTS WITH SEAS BETWEEN 2 AND 4 FEET ARE EXPECTED FOR MOST
WATERS...SO NO HEADLINES PLANNED. THERE IS A LOW PROBABILITY THAT A
BRIEF SURGE OF NORTHEAST WIND GUSTS NEAR 25 KNOTS WITH MARGINAL 5
FOOT SEAS COULD AFFECT OUR NORTHERN WATERS LATE TONIGHT INTO SUN
MORNING...BUT NOT CONFIDENT ENOUGH TO ISSUE ANY HEADLINES AT THIS
POINT.

OUTLOOK...SUNDAY NIGHT INTO WEDNESDAY...MODERATE TO HIGH
CONFIDENCE.

SUNDAY INTO MONDAY. CONTINUOUS NORTHEAST FLOW WILL KEEP SEAS CHOPPY.
LINGERING NORTHEAST SWELL MAY BUMP SEAS ABOVE 5FT ESP ACROSS THE
NORTHEASTERN WATERS. SCA MAY BE NEEDED...BUT LOWER CONFIDENCE.

TUESDAY INTO WEDNESDAY...NE WINDS WILL INCREASE...GUSTING TO 30 KT
TUE THEN SHIFT TO SE GUSTING TO 30-35 KT WED...HIGHEST ON THE OUTER
WATERS. SEAS BUILD UP TO 7-11 FT BY WED. GALES WILL BE NEEDED.

&&

.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES WILL OCCUR TUESDAY THROUGH THURSDAY. BREAKING
IT DOWN...ON TUESDAY HIGH TIDE AT BOSTON WILL BE 11.6 FT. THERE WILL
BE ONSHORE FLOW DURING THIS HIGH TIDE ALLOWING FOR MINOR SPLASHOVER.
IF WIND GUSTS INCREASE THEN COULD POSSIBLE SEE MINOR COASTAL
FLOODING.

ON WEDNESDAY...WINDS WILL SWITCH TO A MORE SOUTHEASTERLY FLOW DURING
THE DAY AND INCREASE QUICKLY FROM APPROACHING SYSTEM AND DESCENT
PRESSURE FALLS. WEDNESDAY AFTERNOON HIGH TIDE IN BOSTON IS 11.7 FT
AND WITH ANY STRENGTH ON THE EASTERLY WIND FLOW WILL PUSH THE TIDE
OVER. RIGHT NOW BELIEVE MINOR COASTAL FLOODING IS POSSIBLE ALONG THE
EAST COASTLINE. HOWEVER WEDNESDAY EVENING...THE WIND GOES IN A MORE
SOUTHERLY DIRECTION AND HIGH TIDE IN PROVIDENCE WILL BE 5.2 FT. 925
MB LLJ STRENGTHENS TO 50-60 KTS WHICH COULD PUSH A DESCENT SURGE UP
ALONG THE SOUTH COAST DURING THE TIME OF HIGH TIDE. THINKING THAT
MINOR COASTAL FLOODING COULD OCCUR BUT CANNOT RULE OUT MODERATE
ALONG THE SOUTH COAST...ESP IF LLJ STRENGTHENS EVEN MORE.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...FRANK/DUNTEN
NEAR TERM...FRANK/DUNTEN
SHORT TERM...FRANK
LONG TERM...DUNTEN
AVIATION...FRANK/DUNTEN
MARINE...FRANK/DUNTEN
TIDES/COASTAL FLOODING...





000
FXUS61 KBOX 201000
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
500 AM EST SAT DEC 20 2014

.SYNOPSIS...
SCATTERED SNOW SHOWERS WILL GRADUALLY OVERSPREAD THE REGION FROM
EAST TO WEST LATER TODAY INTO SUNDAY.  THE EXCEPTION WILL BE THE
IMMEDIATE SOUTHEAST NEW ENGLAND COAST...WHERE IT SHOULD BECOME MILD
ENOUGH FOR SCATTERED RAIN SHOWERS. WEAK LOW PRESSURE WILL PASS SOUTH
OF NEW ENGLAND...BRINGING ANOTHER PERIOD OF PRECIPITATION. A MUCH
STRONGER STORM PASSING WEST OF NEW ENGLAND WILL BRING HEAVY
RAINFALL...GUSTY WINDS AND COASTAL FLOODING CONCERNS TO THE REGION
WEDNESDAY INTO WEDNESDAY EVENING. DRY BUT VERY WINDY CONDITIONS
FOLLOW FOR CHRISTMAS DAY INTO FRIDAY.

&&

.NEAR TERM /UNTIL NOON TODAY/...

430 AM UPDATE...

AN APPROACHING SHORTWAVE HAS ALLOWED WINDS JUST OFF THE GROUND TO
BECOME EASTERLY.  THIS WAS ALLOWING LOW CLOUDS TO BACK INTO
SOUTHEAST MA/RI EARLY THIS MORNING.  EXPECT THIS TREND TO CONTINUE
WITH LOW CLOUDS CONTINUING TO GRADUALLY WORK FURTHER WEST...BUT M.
SUNNY SKIES SHOULD PREVAIL THIS MORNING IN NORTHWEST MA.
MEANWHILE...SOME OCEAN EFFECT FLURRIES/LIGHT SNOW SHOWERS MAY
DEVELOP ACROSS PLYMOUTH COUNTY AND ONTO THE CAPE/ISLANDS THIS
MORNING.

&&

.SHORT TERM /NOON TODAY THROUGH 6 PM SUNDAY/...
THIS AFTERNOON AND TONIGHT...

INTERESTING MESOSCALE SETUP AS AN INVERTED TROUGH COMBINES WITH SOME
OCEAN ENHANCEMENT.  APPROACHING UPPER LEVEL SHORTWAVE WILL ALLOW FOR
EASTERLY FLOW JUST OFF THE GROUND.  THIS COMBINED WITH NORTHEAST
SURFACE WINDS WILL ALLOW LOW LEVEL OF THE ATMOSPHERE TO MOISTEN.
SOUNDINGS ACROSS EASTERN NEW ENGLAND BECOME SATURATED ALL THE WAY UP
TO THE -9C LAYER JUST ABOVE 850 MB.  THIS IS FAVORABLE FOR SOME
DECENT SNOWGROWTH...ITS JUST LOWER IN THE ATMOSPHERE THAN WE
TYPICALLY SEE WITH MORE SYNOPTIC SNOW EVENTS.  WHILE THIS IS NOT A
TRUE OCEAN EFFECT EVENT...DELTA T VALUES FROM THE MIXED LAYER TO THE
OCEAN ARE AROUND 15C.  THEREFORE...EXPECT SOME OCEAN ENHANCEMENT.

TIMING:

WHILE FLURRIES/LIGHT SNOW SHOWERS MAY OCCUR ACROSS FAR SOUTHEAST NEW
ENGLAND THIS MORNING.  THE MORE SUBSTANTIAL  PRECIPITATION SHOULD
OVERSPREAD PLYMOUTH COUNTY AS WELL AS THE CAPE AND ISLANDS THIS
AFTERNOON.  GIVEN EASTERLY FLOW JUST OFF THE GROUND...EXPECT SNOW
SHOWERS TO OVERSPREAD MOST OF EASTERN NEW ENGLAND THIS EVENING AS
LOW LEVELS MOISTEN.  IN FACT...SHOULD SEE AT LEAST SOME SCATTERED
SNOW SHOWERS AFFECT EVEN OUR FAR WESTERN ZONES.

PTYPE:

MAINLY SNOW FOR ALL BUT PORTIONS OF COASTAL PLYMOUTH COUNTY AND ONTO
THE CAPE/ISLANDS.  A SUBTLE COASTAL FRONT LOOKS TO SETUP ACROSS
SOUTHEAST COASTAL PLYMOUTH COUNTY.  PTYPE WILL BE SNOW TO THE
NORTHWEST OF THIS REGION...BUT ENOUGH MILD AIR SHOULD COME IN OFF
THE OCEAN FOR A CHANGE TO RAIN SHOWERS SOUTHEAST OF THIS REGION.
NOT EXPECTING THE POSITION OF THIS SUBTLE BOUNDARY TO CHANGE MUCH
THROUGH SUNDAY MORNING.

SNOW ACCUMULATIONS:

WE ARE GENERALLY LOOKING AT A COATING TO 2 INCHES OF SNOW ACROSS
MOST OF THE REGION.  THE MAIN FOCUS FOR 1 TO 2 INCHES WILL BE ACROSS
PORTIONS OF SOUTHEAST MA...AWAY FROM THE SOUTHEAST PLYMOUTH COUNTY
COAST.  ALSO...THE WORCESTER HILLS INTO NORTHWEST RHODE ISLAND MIGHT
BE ANOTHER AREA AS A RESULT OF THE SUBTLE UPSLOPE COMPONENT TO THE
WIND.  YOU CAN ACTUALLY SEE THAT IN SOME OF THE HIGH RESOLUTION
MODEL GUIDANCE.

THERE IS ONE AREA TO WATCH IN PARTICULAR...FROM NORTHWEST PLYMOUTH
COUNTY AND INTO NORFOLK COUNTY BASED ON MESOSCALE MODELS AND PATTERN
RECOGNITION.  WOULD NOT BE SURPRISED TO SEE VERY LOCALIZED 3 TO 4
INCH SNOW AMOUNTS...GIVEN SOME OCEAN ENHANCEMENT AND A LITTLE FOCUS
ON THE COASTAL FRONT.  WILL TRY TO HIGHLIGHT THIS AREA IN OUR
SNOWFALL AND PROBABILISTIC  GRAPHICS.

SUNDAY...

SCATTERED SNOW SHOWERS WILL CONTINUE DURING THE MORNING WITH MOIST
EASTERLY FLOW IN THE LOW LEVELS. AGAIN...PTYPE WILL BE SNOW EXCEPT
ACROSS SOUTHEAST PLYMOUTH COUNTY/CAPE AND ISLANDS WHERE BOUNDARY
LAYER WILL PROBABLY BE WARM ENOUGH FOR RAIN SHOWERS.  WHILE SOME
LIGHT PRECIPITATION MAY LINGER INTO SUNDAY AFTERNOON...EXPECT A
DECREASE IN AREAL COVERAGE THROUGH THE AFTERNOON AS LOW LEVEL LIFT
WEAKENS.  IT WILL REMAIN CLOUDY THOUGH WITH TEMPS IN THE 30S.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...

HIGHLIGHTS...

* INVERTED TROUGH WILL BRING RAIN/SNOW SHOWERS TO THE MASS EAST
  COASTLINE MONDAY INTO TUES MORNING.
* WEAK WAVE OF LOW PRESSURE MON NIGHT/TUESDAY COULD BRING WINTRY
  MIX TO INTERIOR
* ANOMALOUS SYSTEM ACROSS THE GREAT LAKES WILL BRING HEAVY
  RAIN...GUSTY WINDS AND COASTAL FLOODING CONCERNS AROUND CHRISTMAS
  EVE

OVERVIEW...

OVERALL 00Z GUIDANCE IS IN AGREEMENT SYNOPTICALLY WITH ISSUES ON
TIMING AND SMALLER SCALE FEATURES. IT REMAINS EVIDENT THAT AN
AMPLIFIED MID-UPPER LEVEL TROUGH AND PCPN FOCUSING LEAD SURFACE
LOW/FRONTAL SYSTEM WILL STEADILY PROGRESS TO THE EAST-CENTRAL U.S.
TUE AS EMBEDDED IMPULSES DIG TO THE LEE OF AN AMPLIFIED ERN
PACIFIC/WEST COAST RIDGE ALOFT. THE SUPPORTING AND INCREASINGLY
NEGATIVE-TILT TROUGH ALOFT WORKS OVER THE ERN US AND OUT THROUGH THE
NERN STATES INTO DAYS 4/5 WED/THU.  MODELS/ENSEMBLES HAVE BEEN
FAIRLY CONSISTENT ON THIS AMPLIFIED PATTERN AND THE MOST RECENT
GEFS/ECMWF ENSEMBLE GUIDANCE SHOW GOOD CORRELATION TO NEXT THURSDAY.

HIGH PRESSURE AND UPPER LEVEL RIDGE OVER THE REGION WILL BEGIN TO
EXIT BY MONDAY. AT THE SURFACE APPEARS ANOTHER INVERTED
TROUGH/ONSHORE FLOW WILL YIELD TO PRECIP ALONG THE MASS COASTLINE ON
MONDAY. ASIDE FROM THIS QUICK MESOSCALE EVENT THE MAIN FOCUS IS ON
THE LONGWAVE DIGGING TROUGH OVER THE CENTRAL CONUS WHICH WILL PUSH A
FEW SHORTWAVES THROUGH THE FLOW. FIRST ONE DEVELOPS A WEAK WAVE
MOVING TOWARDS THE REGION LATE MONDAY INTO TUESDAY. THERE IS STILL
SOME UNCERTAINTY WITH THE LOCATION/STRENGTH OF THIS SYSTEM BUT
APPEARS THAT THERE IS THE POSSIBILITY OF A SNOW/WINTRY MIX IN THE
INTERIOR. AS THIS SYSTEM DEPARTS AN ANOMALOUS LOW OVER THE GREAT
LAKES WILL DEVELOP A SECONDARY LOW JUST WEST OF SOUTHERN NEW ENGLAND
...PER ENSEMBLE GUIDANCE. STILL A SOME SPREAD BUT IF THIS DOUBLE LOW
DOES DEVELOP THEN THE RAIN AND WIND ASPECT OF THE SYSTEM
INCREASES...DETAILS BELOW. STILL NEED TO WORK OUT MINOR DETAILS WITH
THIS PARTICULAR SYSTEM BUT WITH 3 TO 4 STANDARD DEVIATIONS AWAY AND
GENERAL MODEL AGREEMENT HAVE HIGH CONFIDENCE THIS SYSTEM WILL IMPACT
SOUTHERN NEW ENGLAND.

DETAILS...

SUNDAY NIGHT INTO TUESDAY...MODERATE CONFIDENCE.

HIGH PRESSURE AND UPPER LEVEL RIDGE WILL BEGIN TO MOVE OFFSHORE AS
DIGGING TROUGH BEGINS TO SET-UP OVER THE CENTRAL CONUS. APPEARS
ANOTHER MESO-SCALE INVERTED TROUGH WILL SET UP ON MONDAY AND LAST
INTO EARLY TUESDAY MORNING. GUIDANCE SHOWS THAT RAIN/SNOW SHOWERS
WILL DEVELOP ALONG THE MASS EAST COASTLINE THANKS TO ONSHORE
EASTERLY FLOW. APPEARS THE COLUMN WILL SATURATE PER BUFKIT SOUNDINGS
AND SOUTHERLY FLOW ALOFT. BOTH THE NAM AND GFS SHOW QPF MAKING IT
ONSHORE DURING THIS TIME FRAME. HOWEVER THE EC IS SLIGHTLY SLOWER
AND KEEP THE BULK OF THE PRECIP JUST OFFSHORE. ADD A CHANCE OF POPS
DUE TO THE NAM/GFS MODEL CONTINUITY.

BY LATE MONDAY NIGHT INTO TUESDAY A SOUTHERN BRANCH STORM SYSTEM
FORMS ALONG THE SE COAST AND TAKES A TRACK OFF THE MID ATLANTIC
COAST. THIS SYSTEM GETS CAUGHT UP WITH THE OVERALL LARGE SCALE
AMPLIFICATION OF THE UPPER AIR PATTERN. THERE IS DECENT WARM
ADVECTION WITH COLD AIR DAMMING ACROSS THE INTERIOR. BIGGEST
QUESTION WILL BE IS THERE ENOUGH MOISTURE FOR PRECIP DURING THIS
TIME FRAME. IF PRECIP OVERRUNS THEN COULD SEE FREEZING RAIN/DRIZZLE
ACROSS THE INTERIOR LATE MONDAY INTO TUESDAY MORNING. DURING THE DAY
ON TUESDAY...GOOD AMOUNT OF WARM AIR WILL PUSH SURFACE TEMPS ABOVE
FREEZING ALLOWING FOR ANY PRECIP TO BE MORE OF THE LIQUID VARIETY
AHEAD OF THE CHRISTMAS EVE STORM. HOWEVER GUIDANCE IS ALWAYS TOO
FAST IN SCOURING TEMPS OUT ESP ACROSS THE CT VALLEY SO WE WILL NEED
TO MONITOR THIS CLOSELY...ESP DUE TO LIGHT WINDS AND THE HIGH IN
EASTERN CANADA.

WE COULD ALSO SEE SOME MINOR COASTAL FLOODING CONCERNS ON TUESDAY. SEE
BELOW FOR MORE DETAILS.

WEDNESDAY INTO THURSDAY...HIGH CONFIDENCE IN SYSTEM LOW CONFIDENCE
ON DETAILS.

STRONG ANOMALOUS SYSTEM WILL STRENGTHEN OVER THE GREAT
LAKES...DEVELOPING A POTENTIAL SECONDARY SURFACE LOW JUST WEST OF
SOUTHERN NEW ENGLAND. STILL A LOT OF DETAILS TO WORK OUT AS THIS
SYSTEM IS STILL 5 DAYS AWAY...HOWEVER ENSEMBLES CONTINUE TO SHOW
STRONG AGREEMENT SO HAVE INCREASING CONFIDENCE THAT A POTENT STORM
WILL OCCUR. LATEST 00Z GUIDANCE SHOWS THAT MOST PRECIP WILL BE
LIQUID WITH A DEEP SUBTROPICAL CONNECTION BACK ACROSS THE GULF OF
MEXICO...PW ANOMALIES FORECAST TO RISE BETWEEN +3 TO +4. CURRENT
PWATS ARE PROGGED ABOVE 1.6 INCHES SO HAVE CONTINUED THE CATEGORICAL
POPS. TEMPERATURES WILL BE WELL ABOVE AVERAGE...IN FACT WE MAY BE
CLOSE AT BREAKING RECORD HIGH TEMPS IF TEMPS WARM TO 60F OR ABOVE ON
CHRISTMAS EVE.  AS THE SYSTEM WRAPS UP INTO CANADA...COLD AIR
ADVECTION SHOULD CIRCULATE AROUND AND BEGIN A TRANSITION FROM
SOUTHWEST TO NORTHEAST IN TURNING P-TYPE TO SNOW. HOWEVER LATEST
GUIDANCE DOES SHOW A QUICK MOVING DRY SLOT SO SNOWFALL WILL STRUGGLE
DUE TO LACK OF MOISTURE.

THIS SYSTEM IS QUITE POTENT SO WE WILL NEED TO WATCH FOR POTENTIAL
HAZARDS. CURRENTLY THINK THAT WE COULD POSSIBLE URBAN FLOODING
ISSUES AS MODELS PROGGED WELL OVER 1.5 INCHES OF QPF. LATEST EC EVEN
SHOWS 2.5 INCHES OF QPF IS POSSIBLE. THE GEFS SHOW A MOISTURE FLUX
AT 850 MB BEING 4 TO 5 STANDARD DEVIATIONS AWAY...AND WITH THE
TROPICAL CONNECTION AND STRONG SOUTHERLY FLOW COULD SEE HIGHER
AMOUNTS DUE TO TOPOGRAPHY ENHANCEMENTS. RAIN FALL RECORDS MAY FALL
IF EVERYTHING FALLS INTO PLACE.

ALSO BELIEVE THAT WE MAY SEE SOME WIND ISSUES WITH THIS SYSTEM.
GUIDANCE RIGHT NOW IS SHOWING A 45 TO 55 KT JET AT 925 MB...HOWEVER
IT WILL BE HARD TO BREAK THE INVERSION WITH THE SOUTHERLY FLOW.
RIGHT NOW BELIEVE THAT WIND ADVISORIES MAY BE NEEDED BUT IF THIS
SYSTEM STRENGTHEN EVEN MORE SO A STRONGER JET IS POSSIBLE.

CONTINUED THE MENTIONED OF ISOLATED THUNDER IN THE FORECAST PER PREV
FORECASTER SUGGESTION. BELIEVE IT COULD BE POSSIBLE AS SOUTHERN NEW
ENGLAND WILL BE IN THE WARM SECTOR...WITH THE ANOMALOUS JET AND
SHOWALTERS CLOSE TO ZERO.

FRIDAY...LOW CONFIDENCE.

ONCE UPPER LEVEL LOW MOVES INTO SOUTHERN CANADA...EXPECT A RATHER
FAST UPPER W FLOW IN PLACE. MAY SEE LEFTOVER SNOW SHOWERS BUT TEMPS
WILL FALL BACK CLOSE TO SEASONAL NORMS.

&&

.AVIATION /10Z SATURDAY THROUGH WEDNESDAY/...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /THROUGH SUNDAY/...

430 AM UPDATE...

TODAY...MODERATE CONFIDENCE.  MVFR CIGS WILL CONTINUE TO OVERSPREAD
EASTERN NEW ENGLAND THIS MORNING AND EVENTUALLY INTO THE INTERIOR
THIS AFTERNOON.  SCATTERED PRECIPITATION WILL OVERSPREAD
SOUTHEAST MA/CAPE/ISLANDS THIS AFTERNOON.  PTYPE MAINLY SNOW SHOWERS
NORTHWEST OF THE SOUTHEAST PLYMOUTH COUNTY COAST AND RAIN SHOWERS
SOUTHEAST OF THAT REGION. LOCALIZED IFR CONDITIONS POSSIBLE JUST
INLAND FROM THE SOUTHEAST NEW ENGLAND COAST...WHERE PTYPE IS SNOW.

TONIGHT AND SUNDAY...MODERATE CONFIDENCE.  MVFR CONDITIONS DOMINATE
IN LOWER CLOUDS AND SCATTERED PRECIPITATION.  LOCALIZED IFR
CONDITIONS POSSIBLE WITH THE BEST CHANCE IN SNOW SHOWERS.
PRECIPITATION AFFECTS MAINLY EASTERN NEW ENGLAND BUT STILL SOME
SCATTERED ACTIVITY ACROSS WESTERN NEW ENGLAND. PTYPE MAINLY SNOW
SHOWERS NORTHWEST OF THE SOUTHEAST PLYMOUTH COUNTY COAST...WITH RAIN
SHOWERS SOUTHEAST OF THAT REGION.

KBOS TERMINAL...MODERATE CONFIDENCE IN TAF.  SNOW SHOWERS MAY ARRIVE
TOWARDS 00Z THIS EVENING.

KBDL TERMINAL...MODERATE CONFIDENCE IN TAF.

OUTLOOK...SUNDAY NIGHT THROUGH WEDNESDAY...

MONDAY INTO TUESDAY...MODERATE CONFIDENCE. EXPECT MOSTLY
VFR...ISOLATED MVFR ALONG THE MASS EAST COASTLINE IN RAIN/SNOW
SHOWERS.

TUESDAY NIGHT INTO WEDNESDAY...MODERATE CONFIDENCE. CONDITIONS WILL
BE DETERIORATING AS HEAVY DOWNPOURS...ISO THUNDER AND GUSTY SOUTHERLY
WINDS MOVE INTO THE REGION BY WEDNESDAY. COULD SEE MVFR TO IFR
CONDITIONS IN CIGS AND VSBYS.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /TODAY THROUGH SUNDAY/...HIGH CONFIDENCE.

HIGH PRESSURE ACROSS QUEBEC WILL RESULT IN PERSISTENT NORTHEAST
WINDS ACROSS THE WATERS THROUGH THE WEEKEND.  WIND GUSTS UP TO 20
KNOTS WITH SEAS BETWEEN 2 AND 4 FEET ARE EXPECTED FOR MOST
WATERS...SO NO HEADLINES PLANNED. THERE IS A LOW PROBABILITY THAT A
BRIEF SURGE OF NORTHEAST WIND GUSTS NEAR 25 KNOTS WITH MARGINAL 5
FOOT SEAS COULD AFFECT OUR NORTHERN WATERS LATE TONIGHT INTO SUN
MORNING...BUT NOT CONFIDENT ENOUGH TO ISSUE ANY HEADLINES AT THIS
POINT.

OUTLOOK...SUNDAY NIGHT INTO WEDNESDAY...MODERATE TO HIGH
CONFIDENCE.

SUNDAY INTO MONDAY. CONTINUOUS NORTHEAST FLOW WILL KEEP SEAS CHOPPY.
LINGERING NORTHEAST SWELL MAY BUMP SEAS ABOVE 5FT ESP ACROSS THE
NORTHEASTERN WATERS. SCA MAY BE NEEDED...BUT LOWER CONFIDENCE.

TUESDAY INTO WEDNESDAY...NE WINDS WILL INCREASE...GUSTING TO 30 KT
TUE THEN SHIFT TO SE GUSTING TO 30-35 KT WED...HIGHEST ON THE OUTER
WATERS. SEAS BUILD UP TO 7-11 FT BY WED. GALES WILL BE NEEDED.

&&

.TIDES/COASTAL FLOODING...

HIGH ASTRONOMICAL TIDES WILL OCCUR TUESDAY THROUGH THURSDAY. BREAKING
IT DOWN...ON TUESDAY HIGH TIDE AT BOSTON WILL BE 11.6 FT. THERE WILL
BE ONSHORE FLOW DURING THIS HIGH TIDE ALLOWING FOR MINOR SPLASHOVER.
IF WIND GUSTS INCREASE THEN COULD POSSIBLE SEE MINOR COASTAL
FLOODING.

ON WEDNESDAY...WINDS WILL SWITCH TO A MORE SOUTHEASTERLY FLOW DURING
THE DAY AND INCREASE QUICKLY FROM APPROACHING SYSTEM AND DESCENT
PRESSURE FALLS. WEDNESDAY AFTERNOON HIGH TIDE IN BOSTON IS 11.7 FT
AND WITH ANY STRENGTH ON THE EASTERLY WIND FLOW WILL PUSH THE TIDE
OVER. RIGHT NOW BELIEVE MINOR COASTAL FLOODING IS POSSIBLE ALONG THE
EAST COASTLINE. HOWEVER WEDNESDAY EVENING...THE WIND GOES IN A MORE
SOUTHERLY DIRECTION AND HIGH TIDE IN PROVIDENCE WILL BE 5.2 FT. 925
MB LLJ STRENGTHENS TO 50-60 KTS WHICH COULD PUSH A DESCENT SURGE UP
ALONG THE SOUTH COAST DURING THE TIME OF HIGH TIDE. THINKING THAT
MINOR COASTAL FLOODING COULD OCCUR BUT CANNOT RULE OUT MODERATE
ALONG THE SOUTH COAST...ESP IF LLJ STRENGTHENS EVEN MORE.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...FRANK/DUNTEN
NEAR TERM...FRANK
SHORT TERM...FRANK
LONG TERM...DUNTEN
AVIATION...FRANK/DUNTEN
MARINE...FRANK/DUNTEN
TIDES/COASTAL FLOODING...DUNTEN





000
FXUS61 KBOX 201000
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
500 AM EST SAT DEC 20 2014

.SYNOPSIS...
SCATTERED SNOW SHOWERS WILL GRADUALLY OVERSPREAD THE REGION FROM
EAST TO WEST LATER TODAY INTO SUNDAY.  THE EXCEPTION WILL BE THE
IMMEDIATE SOUTHEAST NEW ENGLAND COAST...WHERE IT SHOULD BECOME MILD
ENOUGH FOR SCATTERED RAIN SHOWERS. WEAK LOW PRESSURE WILL PASS SOUTH
OF NEW ENGLAND...BRINGING ANOTHER PERIOD OF PRECIPITATION. A MUCH
STRONGER STORM PASSING WEST OF NEW ENGLAND WILL BRING HEAVY
RAINFALL...GUSTY WINDS AND COASTAL FLOODING CONCERNS TO THE REGION
WEDNESDAY INTO WEDNESDAY EVENING. DRY BUT VERY WINDY CONDITIONS
FOLLOW FOR CHRISTMAS DAY INTO FRIDAY.

&&

.NEAR TERM /UNTIL NOON TODAY/...

430 AM UPDATE...

AN APPROACHING SHORTWAVE HAS ALLOWED WINDS JUST OFF THE GROUND TO
BECOME EASTERLY.  THIS WAS ALLOWING LOW CLOUDS TO BACK INTO
SOUTHEAST MA/RI EARLY THIS MORNING.  EXPECT THIS TREND TO CONTINUE
WITH LOW CLOUDS CONTINUING TO GRADUALLY WORK FURTHER WEST...BUT M.
SUNNY SKIES SHOULD PREVAIL THIS MORNING IN NORTHWEST MA.
MEANWHILE...SOME OCEAN EFFECT FLURRIES/LIGHT SNOW SHOWERS MAY
DEVELOP ACROSS PLYMOUTH COUNTY AND ONTO THE CAPE/ISLANDS THIS
MORNING.

&&

.SHORT TERM /NOON TODAY THROUGH 6 PM SUNDAY/...
THIS AFTERNOON AND TONIGHT...

INTERESTING MESOSCALE SETUP AS AN INVERTED TROUGH COMBINES WITH SOME
OCEAN ENHANCEMENT.  APPROACHING UPPER LEVEL SHORTWAVE WILL ALLOW FOR
EASTERLY FLOW JUST OFF THE GROUND.  THIS COMBINED WITH NORTHEAST
SURFACE WINDS WILL ALLOW LOW LEVEL OF THE ATMOSPHERE TO MOISTEN.
SOUNDINGS ACROSS EASTERN NEW ENGLAND BECOME SATURATED ALL THE WAY UP
TO THE -9C LAYER JUST ABOVE 850 MB.  THIS IS FAVORABLE FOR SOME
DECENT SNOWGROWTH...ITS JUST LOWER IN THE ATMOSPHERE THAN WE
TYPICALLY SEE WITH MORE SYNOPTIC SNOW EVENTS.  WHILE THIS IS NOT A
TRUE OCEAN EFFECT EVENT...DELTA T VALUES FROM THE MIXED LAYER TO THE
OCEAN ARE AROUND 15C.  THEREFORE...EXPECT SOME OCEAN ENHANCEMENT.

TIMING:

WHILE FLURRIES/LIGHT SNOW SHOWERS MAY OCCUR ACROSS FAR SOUTHEAST NEW
ENGLAND THIS MORNING.  THE MORE SUBSTANTIAL  PRECIPITATION SHOULD
OVERSPREAD PLYMOUTH COUNTY AS WELL AS THE CAPE AND ISLANDS THIS
AFTERNOON.  GIVEN EASTERLY FLOW JUST OFF THE GROUND...EXPECT SNOW
SHOWERS TO OVERSPREAD MOST OF EASTERN NEW ENGLAND THIS EVENING AS
LOW LEVELS MOISTEN.  IN FACT...SHOULD SEE AT LEAST SOME SCATTERED
SNOW SHOWERS AFFECT EVEN OUR FAR WESTERN ZONES.

PTYPE:

MAINLY SNOW FOR ALL BUT PORTIONS OF COASTAL PLYMOUTH COUNTY AND ONTO
THE CAPE/ISLANDS.  A SUBTLE COASTAL FRONT LOOKS TO SETUP ACROSS
SOUTHEAST COASTAL PLYMOUTH COUNTY.  PTYPE WILL BE SNOW TO THE
NORTHWEST OF THIS REGION...BUT ENOUGH MILD AIR SHOULD COME IN OFF
THE OCEAN FOR A CHANGE TO RAIN SHOWERS SOUTHEAST OF THIS REGION.
NOT EXPECTING THE POSITION OF THIS SUBTLE BOUNDARY TO CHANGE MUCH
THROUGH SUNDAY MORNING.

SNOW ACCUMULATIONS:

WE ARE GENERALLY LOOKING AT A COATING TO 2 INCHES OF SNOW ACROSS
MOST OF THE REGION.  THE MAIN FOCUS FOR 1 TO 2 INCHES WILL BE ACROSS
PORTIONS OF SOUTHEAST MA...AWAY FROM THE SOUTHEAST PLYMOUTH COUNTY
COAST.  ALSO...THE WORCESTER HILLS INTO NORTHWEST RHODE ISLAND MIGHT
BE ANOTHER AREA AS A RESULT OF THE SUBTLE UPSLOPE COMPONENT TO THE
WIND.  YOU CAN ACTUALLY SEE THAT IN SOME OF THE HIGH RESOLUTION
MODEL GUIDANCE.

THERE IS ONE AREA TO WATCH IN PARTICULAR...FROM NORTHWEST PLYMOUTH
COUNTY AND INTO NORFOLK COUNTY BASED ON MESOSCALE MODELS AND PATTERN
RECOGNITION.  WOULD NOT BE SURPRISED TO SEE VERY LOCALIZED 3 TO 4
INCH SNOW AMOUNTS...GIVEN SOME OCEAN ENHANCEMENT AND A LITTLE FOCUS
ON THE COASTAL FRONT.  WILL TRY TO HIGHLIGHT THIS AREA IN OUR
SNOWFALL AND PROBABILISTIC  GRAPHICS.

SUNDAY...

SCATTERED SNOW SHOWERS WILL CONTINUE DURING THE MORNING WITH MOIST
EASTERLY FLOW IN THE LOW LEVELS. AGAIN...PTYPE WILL BE SNOW EXCEPT
ACROSS SOUTHEAST PLYMOUTH COUNTY/CAPE AND ISLANDS WHERE BOUNDARY
LAYER WILL PROBABLY BE WARM ENOUGH FOR RAIN SHOWERS.  WHILE SOME
LIGHT PRECIPITATION MAY LINGER INTO SUNDAY AFTERNOON...EXPECT A
DECREASE IN AREAL COVERAGE THROUGH THE AFTERNOON AS LOW LEVEL LIFT
WEAKENS.  IT WILL REMAIN CLOUDY THOUGH WITH TEMPS IN THE 30S.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...

HIGHLIGHTS...

* INVERTED TROUGH WILL BRING RAIN/SNOW SHOWERS TO THE MASS EAST
  COASTLINE MONDAY INTO TUES MORNING.
* WEAK WAVE OF LOW PRESSURE MON NIGHT/TUESDAY COULD BRING WINTRY
  MIX TO INTERIOR
* ANOMALOUS SYSTEM ACROSS THE GREAT LAKES WILL BRING HEAVY
  RAIN...GUSTY WINDS AND COASTAL FLOODING CONCERNS AROUND CHRISTMAS
  EVE

OVERVIEW...

OVERALL 00Z GUIDANCE IS IN AGREEMENT SYNOPTICALLY WITH ISSUES ON
TIMING AND SMALLER SCALE FEATURES. IT REMAINS EVIDENT THAT AN
AMPLIFIED MID-UPPER LEVEL TROUGH AND PCPN FOCUSING LEAD SURFACE
LOW/FRONTAL SYSTEM WILL STEADILY PROGRESS TO THE EAST-CENTRAL U.S.
TUE AS EMBEDDED IMPULSES DIG TO THE LEE OF AN AMPLIFIED ERN
PACIFIC/WEST COAST RIDGE ALOFT. THE SUPPORTING AND INCREASINGLY
NEGATIVE-TILT TROUGH ALOFT WORKS OVER THE ERN US AND OUT THROUGH THE
NERN STATES INTO DAYS 4/5 WED/THU.  MODELS/ENSEMBLES HAVE BEEN
FAIRLY CONSISTENT ON THIS AMPLIFIED PATTERN AND THE MOST RECENT
GEFS/ECMWF ENSEMBLE GUIDANCE SHOW GOOD CORRELATION TO NEXT THURSDAY.

HIGH PRESSURE AND UPPER LEVEL RIDGE OVER THE REGION WILL BEGIN TO
EXIT BY MONDAY. AT THE SURFACE APPEARS ANOTHER INVERTED
TROUGH/ONSHORE FLOW WILL YIELD TO PRECIP ALONG THE MASS COASTLINE ON
MONDAY. ASIDE FROM THIS QUICK MESOSCALE EVENT THE MAIN FOCUS IS ON
THE LONGWAVE DIGGING TROUGH OVER THE CENTRAL CONUS WHICH WILL PUSH A
FEW SHORTWAVES THROUGH THE FLOW. FIRST ONE DEVELOPS A WEAK WAVE
MOVING TOWARDS THE REGION LATE MONDAY INTO TUESDAY. THERE IS STILL
SOME UNCERTAINTY WITH THE LOCATION/STRENGTH OF THIS SYSTEM BUT
APPEARS THAT THERE IS THE POSSIBILITY OF A SNOW/WINTRY MIX IN THE
INTERIOR. AS THIS SYSTEM DEPARTS AN ANOMALOUS LOW OVER THE GREAT
LAKES WILL DEVELOP A SECONDARY LOW JUST WEST OF SOUTHERN NEW ENGLAND
...PER ENSEMBLE GUIDANCE. STILL A SOME SPREAD BUT IF THIS DOUBLE LOW
DOES DEVELOP THEN THE RAIN AND WIND ASPECT OF THE SYSTEM
INCREASES...DETAILS BELOW. STILL NEED TO WORK OUT MINOR DETAILS WITH
THIS PARTICULAR SYSTEM BUT WITH 3 TO 4 STANDARD DEVIATIONS AWAY AND
GENERAL MODEL AGREEMENT HAVE HIGH CONFIDENCE THIS SYSTEM WILL IMPACT
SOUTHERN NEW ENGLAND.

DETAILS...

SUNDAY NIGHT INTO TUESDAY...MODERATE CONFIDENCE.

HIGH PRESSURE AND UPPER LEVEL RIDGE WILL BEGIN TO MOVE OFFSHORE AS
DIGGING TROUGH BEGINS TO SET-UP OVER THE CENTRAL CONUS. APPEARS
ANOTHER MESO-SCALE INVERTED TROUGH WILL SET UP ON MONDAY AND LAST
INTO EARLY TUESDAY MORNING. GUIDANCE SHOWS THAT RAIN/SNOW SHOWERS
WILL DEVELOP ALONG THE MASS EAST COASTLINE THANKS TO ONSHORE
EASTERLY FLOW. APPEARS THE COLUMN WILL SATURATE PER BUFKIT SOUNDINGS
AND SOUTHERLY FLOW ALOFT. BOTH THE NAM AND GFS SHOW QPF MAKING IT
ONSHORE DURING THIS TIME FRAME. HOWEVER THE EC IS SLIGHTLY SLOWER
AND KEEP THE BULK OF THE PRECIP JUST OFFSHORE. ADD A CHANCE OF POPS
DUE TO THE NAM/GFS MODEL CONTINUITY.

BY LATE MONDAY NIGHT INTO TUESDAY A SOUTHERN BRANCH STORM SYSTEM
FORMS ALONG THE SE COAST AND TAKES A TRACK OFF THE MID ATLANTIC
COAST. THIS SYSTEM GETS CAUGHT UP WITH THE OVERALL LARGE SCALE
AMPLIFICATION OF THE UPPER AIR PATTERN. THERE IS DECENT WARM
ADVECTION WITH COLD AIR DAMMING ACROSS THE INTERIOR. BIGGEST
QUESTION WILL BE IS THERE ENOUGH MOISTURE FOR PRECIP DURING THIS
TIME FRAME. IF PRECIP OVERRUNS THEN COULD SEE FREEZING RAIN/DRIZZLE
ACROSS THE INTERIOR LATE MONDAY INTO TUESDAY MORNING. DURING THE DAY
ON TUESDAY...GOOD AMOUNT OF WARM AIR WILL PUSH SURFACE TEMPS ABOVE
FREEZING ALLOWING FOR ANY PRECIP TO BE MORE OF THE LIQUID VARIETY
AHEAD OF THE CHRISTMAS EVE STORM. HOWEVER GUIDANCE IS ALWAYS TOO
FAST IN SCOURING TEMPS OUT ESP ACROSS THE CT VALLEY SO WE WILL NEED
TO MONITOR THIS CLOSELY...ESP DUE TO LIGHT WINDS AND THE HIGH IN
EASTERN CANADA.

WE COULD ALSO SEE SOME MINOR COASTAL FLOODING CONCERNS ON TUESDAY. SEE
BELOW FOR MORE DETAILS.

WEDNESDAY INTO THURSDAY...HIGH CONFIDENCE IN SYSTEM LOW CONFIDENCE
ON DETAILS.

STRONG ANOMALOUS SYSTEM WILL STRENGTHEN OVER THE GREAT
LAKES...DEVELOPING A POTENTIAL SECONDARY SURFACE LOW JUST WEST OF
SOUTHERN NEW ENGLAND. STILL A LOT OF DETAILS TO WORK OUT AS THIS
SYSTEM IS STILL 5 DAYS AWAY...HOWEVER ENSEMBLES CONTINUE TO SHOW
STRONG AGREEMENT SO HAVE INCREASING CONFIDENCE THAT A POTENT STORM
WILL OCCUR. LATEST 00Z GUIDANCE SHOWS THAT MOST PRECIP WILL BE
LIQUID WITH A DEEP SUBTROPICAL CONNECTION BACK ACROSS THE GULF OF
MEXICO...PW ANOMALIES FORECAST TO RISE BETWEEN +3 TO +4. CURRENT
PWATS ARE PROGGED ABOVE 1.6 INCHES SO HAVE CONTINUED THE CATEGORICAL
POPS. TEMPERATURES WILL BE WELL ABOVE AVERAGE...IN FACT WE MAY BE
CLOSE AT BREAKING RECORD HIGH TEMPS IF TEMPS WARM TO 60F OR ABOVE ON
CHRISTMAS EVE.  AS THE SYSTEM WRAPS UP INTO CANADA...COLD AIR
ADVECTION SHOULD CIRCULATE AROUND AND BEGIN A TRANSITION FROM
SOUTHWEST TO NORTHEAST IN TURNING P-TYPE TO SNOW. HOWEVER LATEST
GUIDANCE DOES SHOW A QUICK MOVING DRY SLOT SO SNOWFALL WILL STRUGGLE
DUE TO LACK OF MOISTURE.

THIS SYSTEM IS QUITE POTENT SO WE WILL NEED TO WATCH FOR POTENTIAL
HAZARDS. CURRENTLY THINK THAT WE COULD POSSIBLE URBAN FLOODING
ISSUES AS MODELS PROGGED WELL OVER 1.5 INCHES OF QPF. LATEST EC EVEN
SHOWS 2.5 INCHES OF QPF IS POSSIBLE. THE GEFS SHOW A MOISTURE FLUX
AT 850 MB BEING 4 TO 5 STANDARD DEVIATIONS AWAY...AND WITH THE
TROPICAL CONNECTION AND STRONG SOUTHERLY FLOW COULD SEE HIGHER
AMOUNTS DUE TO TOPOGRAPHY ENHANCEMENTS. RAIN FALL RECORDS MAY FALL
IF EVERYTHING FALLS INTO PLACE.

ALSO BELIEVE THAT WE MAY SEE SOME WIND ISSUES WITH THIS SYSTEM.
GUIDANCE RIGHT NOW IS SHOWING A 45 TO 55 KT JET AT 925 MB...HOWEVER
IT WILL BE HARD TO BREAK THE INVERSION WITH THE SOUTHERLY FLOW.
RIGHT NOW BELIEVE THAT WIND ADVISORIES MAY BE NEEDED BUT IF THIS
SYSTEM STRENGTHEN EVEN MORE SO A STRONGER JET IS POSSIBLE.

CONTINUED THE MENTIONED OF ISOLATED THUNDER IN THE FORECAST PER PREV
FORECASTER SUGGESTION. BELIEVE IT COULD BE POSSIBLE AS SOUTHERN NEW
ENGLAND WILL BE IN THE WARM SECTOR...WITH THE ANOMALOUS JET AND
SHOWALTERS CLOSE TO ZERO.

FRIDAY...LOW CONFIDENCE.

ONCE UPPER LEVEL LOW MOVES INTO SOUTHERN CANADA...EXPECT A RATHER
FAST UPPER W FLOW IN PLACE. MAY SEE LEFTOVER SNOW SHOWERS BUT TEMPS
WILL FALL BACK CLOSE TO SEASONAL NORMS.

&&

.AVIATION /10Z SATURDAY THROUGH WEDNESDAY/...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /THROUGH SUNDAY/...

430 AM UPDATE...

TODAY...MODERATE CONFIDENCE.  MVFR CIGS WILL CONTINUE TO OVERSPREAD
EASTERN NEW ENGLAND THIS MORNING AND EVENTUALLY INTO THE INTERIOR
THIS AFTERNOON.  SCATTERED PRECIPITATION WILL OVERSPREAD
SOUTHEAST MA/CAPE/ISLANDS THIS AFTERNOON.  PTYPE MAINLY SNOW SHOWERS
NORTHWEST OF THE SOUTHEAST PLYMOUTH COUNTY COAST AND RAIN SHOWERS
SOUTHEAST OF THAT REGION. LOCALIZED IFR CONDITIONS POSSIBLE JUST
INLAND FROM THE SOUTHEAST NEW ENGLAND COAST...WHERE PTYPE IS SNOW.

TONIGHT AND SUNDAY...MODERATE CONFIDENCE.  MVFR CONDITIONS DOMINATE
IN LOWER CLOUDS AND SCATTERED PRECIPITATION.  LOCALIZED IFR
CONDITIONS POSSIBLE WITH THE BEST CHANCE IN SNOW SHOWERS.
PRECIPITATION AFFECTS MAINLY EASTERN NEW ENGLAND BUT STILL SOME
SCATTERED ACTIVITY ACROSS WESTERN NEW ENGLAND. PTYPE MAINLY SNOW
SHOWERS NORTHWEST OF THE SOUTHEAST PLYMOUTH COUNTY COAST...WITH RAIN
SHOWERS SOUTHEAST OF THAT REGION.

KBOS TERMINAL...MODERATE CONFIDENCE IN TAF.  SNOW SHOWERS MAY ARRIVE
TOWARDS 00Z THIS EVENING.

KBDL TERMINAL...MODERATE CONFIDENCE IN TAF.

OUTLOOK...SUNDAY NIGHT THROUGH WEDNESDAY...

MONDAY INTO TUESDAY...MODERATE CONFIDENCE. EXPECT MOSTLY
VFR...ISOLATED MVFR ALONG THE MASS EAST COASTLINE IN RAIN/SNOW
SHOWERS.

TUESDAY NIGHT INTO WEDNESDAY...MODERATE CONFIDENCE. CONDITIONS WILL
BE DETERIORATING AS HEAVY DOWNPOURS...ISO THUNDER AND GUSTY SOUTHERLY
WINDS MOVE INTO THE REGION BY WEDNESDAY. COULD SEE MVFR TO IFR
CONDITIONS IN CIGS AND VSBYS.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /TODAY THROUGH SUNDAY/...HIGH CONFIDENCE.

HIGH PRESSURE ACROSS QUEBEC WILL RESULT IN PERSISTENT NORTHEAST
WINDS ACROSS THE WATERS THROUGH THE WEEKEND.  WIND GUSTS UP TO 20
KNOTS WITH SEAS BETWEEN 2 AND 4 FEET ARE EXPECTED FOR MOST
WATERS...SO NO HEADLINES PLANNED. THERE IS A LOW PROBABILITY THAT A
BRIEF SURGE OF NORTHEAST WIND GUSTS NEAR 25 KNOTS WITH MARGINAL 5
FOOT SEAS COULD AFFECT OUR NORTHERN WATERS LATE TONIGHT INTO SUN
MORNING...BUT NOT CONFIDENT ENOUGH TO ISSUE ANY HEADLINES AT THIS
POINT.

OUTLOOK...SUNDAY NIGHT INTO WEDNESDAY...MODERATE TO HIGH
CONFIDENCE.

SUNDAY INTO MONDAY. CONTINUOUS NORTHEAST FLOW WILL KEEP SEAS CHOPPY.
LINGERING NORTHEAST SWELL MAY BUMP SEAS ABOVE 5FT ESP ACROSS THE
NORTHEASTERN WATERS. SCA MAY BE NEEDED...BUT LOWER CONFIDENCE.

TUESDAY INTO WEDNESDAY...NE WINDS WILL INCREASE...GUSTING TO 30 KT
TUE THEN SHIFT TO SE GUSTING TO 30-35 KT WED...HIGHEST ON THE OUTER
WATERS. SEAS BUILD UP TO 7-11 FT BY WED. GALES WILL BE NEEDED.

&&

.TIDES/COASTAL FLOODING...

HIGH ASTRONOMICAL TIDES WILL OCCUR TUESDAY THROUGH THURSDAY. BREAKING
IT DOWN...ON TUESDAY HIGH TIDE AT BOSTON WILL BE 11.6 FT. THERE WILL
BE ONSHORE FLOW DURING THIS HIGH TIDE ALLOWING FOR MINOR SPLASHOVER.
IF WIND GUSTS INCREASE THEN COULD POSSIBLE SEE MINOR COASTAL
FLOODING.

ON WEDNESDAY...WINDS WILL SWITCH TO A MORE SOUTHEASTERLY FLOW DURING
THE DAY AND INCREASE QUICKLY FROM APPROACHING SYSTEM AND DESCENT
PRESSURE FALLS. WEDNESDAY AFTERNOON HIGH TIDE IN BOSTON IS 11.7 FT
AND WITH ANY STRENGTH ON THE EASTERLY WIND FLOW WILL PUSH THE TIDE
OVER. RIGHT NOW BELIEVE MINOR COASTAL FLOODING IS POSSIBLE ALONG THE
EAST COASTLINE. HOWEVER WEDNESDAY EVENING...THE WIND GOES IN A MORE
SOUTHERLY DIRECTION AND HIGH TIDE IN PROVIDENCE WILL BE 5.2 FT. 925
MB LLJ STRENGTHENS TO 50-60 KTS WHICH COULD PUSH A DESCENT SURGE UP
ALONG THE SOUTH COAST DURING THE TIME OF HIGH TIDE. THINKING THAT
MINOR COASTAL FLOODING COULD OCCUR BUT CANNOT RULE OUT MODERATE
ALONG THE SOUTH COAST...ESP IF LLJ STRENGTHENS EVEN MORE.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...FRANK/DUNTEN
NEAR TERM...FRANK
SHORT TERM...FRANK
LONG TERM...DUNTEN
AVIATION...FRANK/DUNTEN
MARINE...FRANK/DUNTEN
TIDES/COASTAL FLOODING...DUNTEN




000
FXUS61 KBOX 200935
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
435 AM EST SAT DEC 20 2014

.SYNOPSIS...
SCATTERED SNOW SHOWERS WILL GRADUALLY OVERSPREAD THE REGION FROM
EAST TO WEST LATER TODAY INTO SUNDAY.  THE EXCEPTION WILL BE THE
IMMEDIATE SOUTHEAST NEW ENGLAND COAST...WHERE IT SHOULD BECOME MILD
ENOUGH FOR SCATTERED RAIN SHOWERS. WEAK LOW PRESSURE WILL PASS SOUTH
OF NEW ENGLAND...BRINGING ANOTHER PERIOD OF PRECIPITATION. A MUCH
STRONGER STORM PASSING WEST OF NEW ENGLAND WILL BRING HEAVY
RAINFALL...GUSTY WINDS AND COASTAL FLOODING CONCERNS TO THE REGION
WEDNESDAY INTO WEDNESDAY EVENING. DRY BUT VERY WINDY CONDITIONS
FOLLOW FOR CHRISTMAS DAY INTO FRIDAY.

&&

.NEAR TERM /UNTIL NOON TODAY/...

430 AM UPDATE...

AN APPROACHING SHORTWAVE HAS ALLOWED WINDS JUST OFF THE GROUND TO
BECOME EASTERLY.  THIS WAS ALLOWING LOW CLOUDS TO BACK INTO
SOUTHEAST MA/RI EARLY THIS MORNING.  EXPECT THIS TREND TO CONTINUE
WITH LOW CLOUDS CONTINUING TO GRADUALLY WORK FURTHER WEST...BUT M.
SUNNY SKIES SHOULD PREVAIL THIS MORNING IN NORTHWEST MA.
MEANWHILE...SOME OCEAN EFFECT FLURRIES/LIGHT SNOW SHOWERS MAY
DEVELOP ACROSS PLYMOUTH COUNTY AND ONTO THE CAPE/ISLANDS THIS
MORNING.

&&

.SHORT TERM /NOON TODAY THROUGH 6 PM SUNDAY/...
THIS AFTERNOON AND TONIGHT...

INTERESTING MESOSCALE SETUP AS AN INVERTED TROUGH COMBINES WITH SOME
OCEAN ENHANCEMENT.  APPROACHING UPPER LEVEL SHORTWAVE WILL ALLOW FOR
EASTERLY FLOW JUST OFF THE GROUND.  THIS COMBINED WITH NORTHEAST
SURFACE WINDS WILL ALLOW LOW LEVEL OF THE ATMOSPHERE TO MOISTEN.
SOUNDINGS ACROSS EASTERN NEW ENGLAND BECOME SATURATED ALL THE WAY UP
TO THE -9C LAYER JUST ABOVE 850 MB.  THIS IS FAVORABLE FOR SOME
DECENT SNOWGROWTH...ITS JUST LOWER IN THE ATMOSPHERE THAN WE
TYPICALLY SEE WITH MORE SYNOPTIC SNOW EVENTS.  WHILE THIS IS NOT A
TRUE OCEAN EFFECT EVENT...DELTA T VALUES FROM THE MIXED LAYER TO THE
OCEAN ARE AROUND 15C.  THEREFORE...EXPECT SOME OCEAN ENHANCEMENT.

TIMING:

WHILE FLURRIES/LIGHT SNOW SHOWERS MAY OCCUR ACROSS FAR SOUTHEAST NEW
ENGLAND THIS MORNING.  THE MORE SUBSTANTIAL  PRECIPITATION SHOULD
OVERSPREAD PLYMOUTH COUNTY AS WELL AS THE CAPE AND ISLANDS THIS
AFTERNOON.  GIVEN EASTERLY FLOW JUST OFF THE GROUND...EXPECT SNOW
SHOWERS TO OVERSPREAD MOST OF EASTERN NEW ENGLAND THIS EVENING AS
LOW LEVELS MOISTEN.  IN FACT...SHOULD SEE AT LEAST SOME SCATTERED
SNOW SHOWERS AFFECT EVEN OUR FAR WESTERN ZONES.

PTYPE:

MAINLY SNOW FOR ALL BUT PORTIONS OF COASTAL PLYMOUTH COUNTY AND ONTO
THE CAPE/ISLANDS.  A SUBTLE COASTAL FRONT LOOKS TO SETUP ACROSS
SOUTHEAST COASTAL PLYMOUTH COUNTY.  PTYPE WILL BE SNOW TO THE
NORTHWEST OF THIS REGION...BUT ENOUGH MILD AIR SHOULD COME IN OFF
THE OCEAN FOR A CHANGE TO RAIN SHOWERS SOUTHEAST OF THIS REGION.
NOT EXPECTING THE POSITION OF THIS SUBTLE BOUNDARY TO CHANGE MUCH
THROUGH SUNDAY MORNING.

SNOW ACCUMULATIONS:

WE ARE GENERALLY LOOKING AT A COATING TO 2 INCHES OF SNOW ACROSS
MOST OF THE REGION.  THE MAIN FOCUS FOR 1 TO 2 INCHES WILL BE ACROSS
PORTIONS OF SOUTHEAST MA...AWAY FROM THE SOUTHEAST PLYMOUTH COUNTY
COAST.  ALSO...THE WORCESTER HILLS INTO NORTHWEST RHODE ISLAND MIGHT
BE ANOTHER AREA AS A RESULT OF THE SUBTLE UPSLOPE COMPONENT TO THE
WIND.  YOU CAN ACTUALLY SEE THAT IN SOME OF THE HIGH RESOLUTION
MODEL GUIDANCE.

THERE IS ONE AREA TO WATCH IN PARTICULAR...JUST INLAND FROM
NORTHWEST PLYMOUTH COUNTY AND INTO NORFOLK COUNTY BASED ON MESOSCALE
MODELS AND PATTERN RECOGNITION.  WOULD NOT BE SURPRISED TO SEE VERY
LOCALIZED 3 TO 4 INCH SNOW AMOUNTS...GIVEN SOME OCEAN ENHANCEMENT
AND A LITTLE FOCUS ON THE COASTAL FRONT.  WILL TRY TO HIGHLIGHT THIS
AREA IN OUR SNOWFALL AND PROBABILISTIC  GRAPHICS.

SUNDAY...

SCATTERED SNOW SHOWERS WILL CONTINUE DURING THE MORNING WITH MOST
EASTERLY FLOW IN THE LOW LEVELS. AGAIN...PTYPE WILL BE SNOW EXCEPT
ACROSS SOUTHEAST PLYMOUTH COUNTY/CAPE AND ISLANDS WHERE BOUNDARY
LAYER WILL PROBABLY BE WARM ENOUGH FOR RAIN SHOWERS.  WHILE SOME
LIGHT PRECIPITATION MAY LINGER INTO SUNDAY AFTERNOON...EXPECT A
DECREASE IN AREAL COVERAGE THROUGH THE AFTERNOON AS LOW LEVEL LIFT
WEAKENS.  IT WILL REMAIN CLOUDY THOUGH WITH TEMPS IN THE 30S.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...

HIGHLIGHTS...

* INVERTED TROUGH WILL BRING RAIN/SNOW SHOWERS TO THE MASS EAST
  COASTLINE MONDAY INTO TUES MORNING.
* WEAK WAVE OF LOW PRESSURE MON NIGHT/TUESDAY COULD BRING WINTRY
  MIX TO INTERIOR
* ANOMALOUS SYSTEM ACROSS THE GREAT LAKES WILL BRING HEAVY
  RAIN...GUSTY WINDS AND COASTAL FLOODING CONCERNS AROUND CHRISTMAS
  EVE

OVERVIEW...

OVERALL 00Z GUIDANCE IS IN AGREEMENT SYNOPTICALLY WITH ISSUES ON
TIMING AND SMALLER SCALE FEATURES. IT REMAINS EVIDENT THAT AN
AMPLIFIED MID-UPPER LEVEL TROUGH AND PCPN FOCUSING LEAD SURFACE
LOW/FRONTAL SYSTEM WILL STEADILY PROGRESS TO THE EAST-CENTRAL U.S.
TUE AS EMBEDDED IMPULSES DIG TO THE LEE OF AN AMPLIFIED ERN
PACIFIC/WEST COAST RIDGE ALOFT. THE SUPPORTING AND INCREASINGLY
NEGATIVE-TILT TROUGH ALOFT WORKS OVER THE ERN US AND OUT THROUGH THE
NERN STATES INTO DAYS 4/5 WED/THU.  MODELS/ENSEMBLES HAVE BEEN
FAIRLY CONSISTENT ON THIS AMPLIFIED PATTERN AND THE MOST RECENT
GEFS/ECMWF ENSEMBLE GUIDANCE SHOW GOOD CORRELATION TO NEXT THURSDAY.

HIGH PRESSURE AND UPPER LEVEL RIDGE OVER THE REGION WILL BEGIN TO
EXIT BY MONDAY. AT THE SURFACE APPEARS ANOTHER INVERTED
TROUGH/ONSHORE FLOW WILL YIELD TO PRECIP ALONG THE MASS COASTLINE ON
MONDAY. ASIDE FROM THIS QUICK MESOSCALE EVENT THE MAIN FOCUS IS ON
THE LONGWAVE DIGGING TROUGH OVER THE CENTRAL CONUS WHICH WILL PUSH A
FEW SHORTWAVES THROUGH THE FLOW. FIRST ONE DEVELOPS A WEAK WAVE
MOVING TOWARDS THE REGION LATE MONDAY INTO TUESDAY. THERE IS STILL
SOME UNCERTAINTY WITH THE LOCATION/STRENGTH OF THIS SYSTEM BUT
APPEARS THAT THERE IS THE POSSIBILITY OF A SNOW/WINTRY MIX IN THE
INTERIOR. AS THIS SYSTEM DEPARTS AN ANOMALOUS LOW OVER THE GREAT
LAKES WILL DEVELOP A SECONDARY LOW JUST WEST OF SOUTHERN NEW ENGLAND
...PER ENSEMBLE GUIDANCE. STILL A SOME SPREAD BUT IF THIS DOUBLE LOW
DOES DEVELOP THEN THE RAIN AND WIND ASPECT OF THE SYSTEM
INCREASES...DETAILS BELOW. STILL NEED TO WORK OUT MINOR DETAILS WITH
THIS PARTICULAR SYSTEM BUT WITH 3 TO 4 STANDARD DEVIATIONS AWAY AND
GENERAL MODEL AGREEMENT HAVE HIGH CONFIDENCE THIS SYSTEM WILL IMPACT
SOUTHERN NEW ENGLAND.

DETAILS...

SUNDAY NIGHT INTO TUESDAY...MODERATE CONFIDENCE.

HIGH PRESSURE AND UPPER LEVEL RIDGE WILL BEGIN TO MOVE OFFSHORE AS
DIGGING TROUGH BEGINS TO SET-UP OVER THE CENTRAL CONUS. APPEARS
ANOTHER MESO-SCALE INVERTED TROUGH WILL SET UP ON MONDAY AND LAST
INTO EARLY TUESDAY MORNING. GUIDANCE SHOWS THAT RAIN/SNOW SHOWERS
WILL DEVELOP ALONG THE MASS EAST COASTLINE THANKS TO ONSHORE
EASTERLY FLOW. APPEARS THE COLUMN WILL SATURATE PER BUFKIT SOUNDINGS
AND SOUTHERLY FLOW ALOFT. BOTH THE NAM AND GFS SHOW QPF MAKING IT
ONSHORE DURING THIS TIME FRAME. HOWEVER THE EC IS SLIGHTLY SLOWER
AND KEEP THE BULK OF THE PRECIP JUST OFFSHORE. ADD A CHANCE OF POPS
DUE TO THE NAM/GFS MODEL CONTINUITY.

BY LATE MONDAY NIGHT INTO TUESDAY A SOUTHERN BRANCH STORM SYSTEM
FORMS ALONG THE SE COAST AND TAKES A TRACK OFF THE MID ATLANTIC
COAST. THIS SYSTEM GETS CAUGHT UP WITH THE OVERALL LARGE SCALE
AMPLIFICATION OF THE UPPER AIR PATTERN. THERE IS DECENT WARM
ADVECTION WITH COLD AIR DAMMING ACROSS THE INTERIOR. BIGGEST
QUESTION WILL BE IS THERE ENOUGH MOISTURE FOR PRECIP DURING THIS
TIME FRAME. IF PRECIP OVERRUNS THEN COULD SEE FREEZING RAIN/DRIZZLE
ACROSS THE INTERIOR LATE MONDAY INTO TUESDAY MORNING. DURING THE DAY
ON TUESDAY...GOOD AMOUNT OF WARM AIR WILL PUSH SURFACE TEMPS ABOVE
FREEZING ALLOWING FOR ANY PRECIP TO BE MORE OF THE LIQUID VARIETY
AHEAD OF THE CHRISTMAS EVE STORM. HOWEVER GUIDANCE IS ALWAYS TOO
FAST IN SCOURING TEMPS OUT ESP ACROSS THE CT VALLEY SO WE WILL NEED
TO MONITOR THIS CLOSELY...ESP DUE TO LIGHT WINDS AND THE HIGH IN
EASTERN CANADA.

WE COULD ALSO SEE SOME MINOR COASTAL FLOODING CONCERNS ON TUESDAY. SEE
BELOW FOR MORE DETAILS.

WEDNESDAY INTO THURSDAY...HIGH CONFIDENCE IN SYSTEM LOW CONFIDENCE
ON DETAILS.

STRONG ANOMALOUS SYSTEM WILL STRENGTHEN OVER THE GREAT
LAKES...DEVELOPING A POTENTIAL SECONDARY SURFACE LOW JUST WEST OF
SOUTHERN NEW ENGLAND. STILL A LOT OF DETAILS TO WORK OUT AS THIS
SYSTEM IS STILL 5 DAYS AWAY...HOWEVER ENSEMBLES CONTINUE TO SHOW
STRONG AGREEMENT SO HAVE INCREASING CONFIDENCE THAT A POTENT STORM
WILL OCCUR. LATEST 00Z GUIDANCE SHOWS THAT MOST PRECIP WILL BE
LIQUID WITH A DEEP SUBTROPICAL CONNECTION BACK ACROSS THE GULF OF
MEXICO...PW ANOMALIES FORECAST TO RISE BETWEEN +3 TO +4. CURRENT
PWATS ARE PROGGED ABOVE 1.6 INCHES SO HAVE CONTINUED THE CATEGORICAL
POPS. TEMPERATURES WILL BE WELL ABOVE AVERAGE...IN FACT WE MAY BE
CLOSE AT BREAKING RECORD HIGH TEMPS IF TEMPS WARM TO 60F OR ABOVE ON
CHRISTMAS EVE.  AS THE SYSTEM WRAPS UP INTO CANADA...COLD AIR
ADVECTION SHOULD CIRCULATE AROUND AND BEGIN A TRANSITION FROM
SOUTHWEST TO NORTHEAST IN TURNING P-TYPE TO SNOW. HOWEVER LATEST
GUIDANCE DOES SHOW A QUICK MOVING DRY SLOT SO SNOWFALL WILL STRUGGLE
DUE TO LACK OF MOISTURE.

THIS SYSTEM IS QUITE POTENT SO WE WILL NEED TO WATCH FOR POTENTIAL
HAZARDS. CURRENTLY THINK THAT WE COULD POSSIBLE URBAN FLOODING
ISSUES AS MODELS PROGGED WELL OVER 1.5 INCHES OF QPF. LATEST EC EVEN
SHOWS 2.5 INCHES OF QPF IS POSSIBLE. THE GEFS SHOW A MOISTURE FLUX
AT 850 MB BEING 4 TO 5 STANDARD DEVIATIONS AWAY...AND WITH THE
TROPICAL CONNECTION AND STRONG SOUTHERLY FLOW COULD SEE HIGHER
AMOUNTS DUE TO TOPOGRAPHY ENHANCEMENTS. RAIN FALL RECORDS MAY FALL
IF EVERYTHING FALLS INTO PLACE.

ALSO BELIEVE THAT WE MAY SEE SOME WIND ISSUES WITH THIS SYSTEM.
GUIDANCE RIGHT NOW IS SHOWING A 45 TO 55 KT JET AT 925 MB...HOWEVER
IT WILL BE HARD TO BREAK THE INVERSION WITH THE SOUTHERLY FLOW.
RIGHT NOW BELIEVE THAT WIND ADVISORIES MAY BE NEEDED BUT IF THIS
SYSTEM STRENGTHEN EVEN MORE SO A STRONGER JET IS POSSIBLE.

CONTINUED THE MENTIONED OF ISOLATED THUNDER IN THE FORECAST PER PREV
FORECASTER SUGGESTION. BELIEVE IT COULD BE POSSIBLE AS SOUTHERN NEW
ENGLAND WILL BE IN THE WARM SECTOR...WITH THE ANOMALOUS JET AND
SHOWALTERS CLOSE TO ZERO.

FRIDAY...LOW CONFIDENCE.

ONCE UPPER LEVEL LOW MOVES INTO SOUTHERN CANADA...EXPECT A RATHER
FAST UPPER W FLOW IN PLACE. MAY SEE LEFTOVER SNOW SHOWERS BUT TEMPS
WILL FALL BACK CLOSE TO SEASONAL NORMS.

&&

.AVIATION /10Z SATURDAY THROUGH WEDNESDAY/...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /THROUGH SUNDAY/...

430 AM UPDATE...

TODAY...MODERATE CONFIDENCE.  MVFR CIGS WILL CONTINUE TO OVERSPREAD
EASTERN NEW ENGLAND THIS MORNING AND EVENTUALLY INTO THE INTERIOR
THIS AFTERNOON.  SCATTERED PRECIPITATION WILL OVERSPREAD
SOUTHEAST MA/CAPE/ISLANDS THIS AFTERNOON.  PTYPE MAINLY SNOW SHOWERS
NORTHWEST OF THE SOUTHEAST PLYMOUTH COUNTY COAST AND RAIN SHOWERS
SOUTHEAST OF THAT REGION. LOCALIZED IFR CONDITIONS POSSIBLE JUST
INLAND FROM THE SOUTHEAST NEW ENGLAND COAST...WHERE PTYPE IS SNOW.

TONIGHT AND SUNDAY...MODERATE CONFIDENCE.  MVFR CONDITIONS DOMINATE
IN LOWER CLOUDS AND SCATTERED PRECIPITATION.  LOCALIZED IFR
CONDITIONS POSSIBLE WITH THE BEST CHANCE IN SNOW SHOWERS.
PRECIPITATION AFFECTS MAINLY EASTERN NEW ENGLAND BUT STILL SOME
SCATTERED ACTIVITY ACROSS WESTERN NEW ENGLAND. PTYPE MAINLY SNOW
SHOWERS NORTHWEST OF THE SOUTHEAST PLYMOUTH COUNTY COAST...WITH RAIN
SHOWERS SOUTHEAST OF THAT REGION.

KBOS TERMINAL...MODERATE CONFIDENCE IN TAF.  SNOW SHOWERS MAY ARRIVE
TOWARDS 00Z THIS EVENING.

KBDL TERMINAL...MODERATE CONFIDENCE IN TAF.

OUTLOOK...SUNDAY NIGHT THROUGH WEDNESDAY...

MONDAY INTO TUESDAY...MODERATE CONFIDENCE. EXPECT MOSTLY
VFR...ISOLATED MVFR ALONG THE MASS EAST COASTLINE IN RAIN/SNOW
SHOWERS.

TUESDAY NIGHT INTO WEDNESDAY...MODERATE CONFIDENCE. CONDITIONS WILL
BE DETERIORATING AS HEAVY DOWNPOURS...ISO THUNDER AND GUSTY SOUTHERLY
WINDS MOVE INTO THE REGION BY WEDNESDAY. COULD SEE MVFR TO IFR
CONDITIONS IN CIGS AND VSBYS.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /TODAY THROUGH SUNDAY/...HIGH CONFIDENCE.

HIGH PRESSURE ACROSS QUEBEC WILL RESULT IN PERSISTENT NORTHEAST
WINDS ACROSS THE WATERS THROUGH THE WEEKEND.  WIND GUSTS UP TO 20
KNOTS WITH SEAS BETWEEN 2 AND 4 FEET ARE EXPECTED FOR MOST
WATERS...SO NO HEADLINES PLANNED. THERE IS A LOW PROBABILITY THAT A
BRIEF SURGE OF NORTHEAST WIND GUSTS NEAR 25 KNOTS WITH MARGINAL 5
FOOT SEAS COULD AFFECT OUR NORTHERN WATERS LATE TONIGHT INTO SUN
MORNING...BUT NOT CONFIDENT ENOUGH TO ISSUE ANY HEADLINES AT THIS
POINT.

OUTLOOK...SUNDAY NIGHT INTO WEDNESDAY...MODERATE TO HIGH
CONFIDENCE.

SUNDAY INTO MONDAY. CONTINUOUS NORTHEAST FLOW WILL KEEP SEAS CHOPPY.
LINGERING NORTHEAST SWELL MAY BUMP SEAS ABOVE 5FT ESP ACROSS THE
NORTHEASTERN WATERS. SCA MAY BE NEEDED...BUT LOWER CONFIDENCE.

TUESDAY INTO WEDNESDAY...NE WINDS WILL INCREASE...GUSTING TO 30 KT
TUE THEN SHIFT TO SE GUSTING TO 30-35 KT WED...HIGHEST ON THE OUTER
WATERS. SEAS BUILD UP TO 7-11 FT BY WED. GALES WILL BE NEEDED.

&&

.TIDES/COASTAL FLOODING...

HIGH ASTRONOMICAL TIDES WILL OCCUR TUESDAY THROUGH THURSDAY. BREAKING
IT DOWN...ON TUESDAY HIGH TIDE AT BOSTON WILL BE 11.6 FT. THERE WILL
BE ONSHORE FLOW DURING THIS HIGH TIDE ALLOWING FOR MINOR SPLASHOVER.
IF WIND GUSTS INCREASE THEN COULD POSSIBLE SEE MINOR COASTAL
FLOODING.

ON WEDNESDAY...WINDS WILL SWITCH TO A MORE SOUTHEASTERLY FLOW DURING
THE DAY AND INCREASE QUICKLY FROM APPROACHING SYSTEM AND DESCENT
PRESSURE FALLS. WEDNESDAY AFTERNOON HIGH TIDE IN BOSTON IS 11.7 FT
AND WITH ANY STRENGTH ON THE EASTERLY WIND FLOW WILL PUSH THE TIDE
OVER. RIGHT NOW BELIEVE MINOR COASTAL FLOODING IS POSSIBLE ALONG THE
EAST COASTLINE. HOWEVER WEDNESDAY EVENING...THE WIND GOES IN A MORE
SOUTHERLY DIRECTION AND HIGH TIDE IN PROVIDENCE WILL BE 5.2 FT. 925
MB LLJ STRENGTHENS TO 50-60 KTS WHICH COULD PUSH A DESCENT SURGE UP
ALONG THE SOUTH COAST DURING THE TIME OF HIGH TIDE. THINKING THAT
MINOR COASTAL FLOODING COULD OCCUR BUT CANNOT RULE OUT MODERATE
ALONG THE SOUTH COAST...ESP IF LLJ STRENGTHENS EVEN MORE.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...FRANK/DUNTEN
NEAR TERM...FRANK
SHORT TERM...FRANK
LONG TERM...DUNTEN
AVIATION...FRANK/DUNTEN
MARINE...FRANK/DUNTEN
TIDES/COASTAL FLOODING...DUNTEN





000
FXUS61 KBOX 200935
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
435 AM EST SAT DEC 20 2014

.SYNOPSIS...
SCATTERED SNOW SHOWERS WILL GRADUALLY OVERSPREAD THE REGION FROM
EAST TO WEST LATER TODAY INTO SUNDAY.  THE EXCEPTION WILL BE THE
IMMEDIATE SOUTHEAST NEW ENGLAND COAST...WHERE IT SHOULD BECOME MILD
ENOUGH FOR SCATTERED RAIN SHOWERS. WEAK LOW PRESSURE WILL PASS SOUTH
OF NEW ENGLAND...BRINGING ANOTHER PERIOD OF PRECIPITATION. A MUCH
STRONGER STORM PASSING WEST OF NEW ENGLAND WILL BRING HEAVY
RAINFALL...GUSTY WINDS AND COASTAL FLOODING CONCERNS TO THE REGION
WEDNESDAY INTO WEDNESDAY EVENING. DRY BUT VERY WINDY CONDITIONS
FOLLOW FOR CHRISTMAS DAY INTO FRIDAY.

&&

.NEAR TERM /UNTIL NOON TODAY/...

430 AM UPDATE...

AN APPROACHING SHORTWAVE HAS ALLOWED WINDS JUST OFF THE GROUND TO
BECOME EASTERLY.  THIS WAS ALLOWING LOW CLOUDS TO BACK INTO
SOUTHEAST MA/RI EARLY THIS MORNING.  EXPECT THIS TREND TO CONTINUE
WITH LOW CLOUDS CONTINUING TO GRADUALLY WORK FURTHER WEST...BUT M.
SUNNY SKIES SHOULD PREVAIL THIS MORNING IN NORTHWEST MA.
MEANWHILE...SOME OCEAN EFFECT FLURRIES/LIGHT SNOW SHOWERS MAY
DEVELOP ACROSS PLYMOUTH COUNTY AND ONTO THE CAPE/ISLANDS THIS
MORNING.

&&

.SHORT TERM /NOON TODAY THROUGH 6 PM SUNDAY/...
THIS AFTERNOON AND TONIGHT...

INTERESTING MESOSCALE SETUP AS AN INVERTED TROUGH COMBINES WITH SOME
OCEAN ENHANCEMENT.  APPROACHING UPPER LEVEL SHORTWAVE WILL ALLOW FOR
EASTERLY FLOW JUST OFF THE GROUND.  THIS COMBINED WITH NORTHEAST
SURFACE WINDS WILL ALLOW LOW LEVEL OF THE ATMOSPHERE TO MOISTEN.
SOUNDINGS ACROSS EASTERN NEW ENGLAND BECOME SATURATED ALL THE WAY UP
TO THE -9C LAYER JUST ABOVE 850 MB.  THIS IS FAVORABLE FOR SOME
DECENT SNOWGROWTH...ITS JUST LOWER IN THE ATMOSPHERE THAN WE
TYPICALLY SEE WITH MORE SYNOPTIC SNOW EVENTS.  WHILE THIS IS NOT A
TRUE OCEAN EFFECT EVENT...DELTA T VALUES FROM THE MIXED LAYER TO THE
OCEAN ARE AROUND 15C.  THEREFORE...EXPECT SOME OCEAN ENHANCEMENT.

TIMING:

WHILE FLURRIES/LIGHT SNOW SHOWERS MAY OCCUR ACROSS FAR SOUTHEAST NEW
ENGLAND THIS MORNING.  THE MORE SUBSTANTIAL  PRECIPITATION SHOULD
OVERSPREAD PLYMOUTH COUNTY AS WELL AS THE CAPE AND ISLANDS THIS
AFTERNOON.  GIVEN EASTERLY FLOW JUST OFF THE GROUND...EXPECT SNOW
SHOWERS TO OVERSPREAD MOST OF EASTERN NEW ENGLAND THIS EVENING AS
LOW LEVELS MOISTEN.  IN FACT...SHOULD SEE AT LEAST SOME SCATTERED
SNOW SHOWERS AFFECT EVEN OUR FAR WESTERN ZONES.

PTYPE:

MAINLY SNOW FOR ALL BUT PORTIONS OF COASTAL PLYMOUTH COUNTY AND ONTO
THE CAPE/ISLANDS.  A SUBTLE COASTAL FRONT LOOKS TO SETUP ACROSS
SOUTHEAST COASTAL PLYMOUTH COUNTY.  PTYPE WILL BE SNOW TO THE
NORTHWEST OF THIS REGION...BUT ENOUGH MILD AIR SHOULD COME IN OFF
THE OCEAN FOR A CHANGE TO RAIN SHOWERS SOUTHEAST OF THIS REGION.
NOT EXPECTING THE POSITION OF THIS SUBTLE BOUNDARY TO CHANGE MUCH
THROUGH SUNDAY MORNING.

SNOW ACCUMULATIONS:

WE ARE GENERALLY LOOKING AT A COATING TO 2 INCHES OF SNOW ACROSS
MOST OF THE REGION.  THE MAIN FOCUS FOR 1 TO 2 INCHES WILL BE ACROSS
PORTIONS OF SOUTHEAST MA...AWAY FROM THE SOUTHEAST PLYMOUTH COUNTY
COAST.  ALSO...THE WORCESTER HILLS INTO NORTHWEST RHODE ISLAND MIGHT
BE ANOTHER AREA AS A RESULT OF THE SUBTLE UPSLOPE COMPONENT TO THE
WIND.  YOU CAN ACTUALLY SEE THAT IN SOME OF THE HIGH RESOLUTION
MODEL GUIDANCE.

THERE IS ONE AREA TO WATCH IN PARTICULAR...JUST INLAND FROM
NORTHWEST PLYMOUTH COUNTY AND INTO NORFOLK COUNTY BASED ON MESOSCALE
MODELS AND PATTERN RECOGNITION.  WOULD NOT BE SURPRISED TO SEE VERY
LOCALIZED 3 TO 4 INCH SNOW AMOUNTS...GIVEN SOME OCEAN ENHANCEMENT
AND A LITTLE FOCUS ON THE COASTAL FRONT.  WILL TRY TO HIGHLIGHT THIS
AREA IN OUR SNOWFALL AND PROBABILISTIC  GRAPHICS.

SUNDAY...

SCATTERED SNOW SHOWERS WILL CONTINUE DURING THE MORNING WITH MOST
EASTERLY FLOW IN THE LOW LEVELS. AGAIN...PTYPE WILL BE SNOW EXCEPT
ACROSS SOUTHEAST PLYMOUTH COUNTY/CAPE AND ISLANDS WHERE BOUNDARY
LAYER WILL PROBABLY BE WARM ENOUGH FOR RAIN SHOWERS.  WHILE SOME
LIGHT PRECIPITATION MAY LINGER INTO SUNDAY AFTERNOON...EXPECT A
DECREASE IN AREAL COVERAGE THROUGH THE AFTERNOON AS LOW LEVEL LIFT
WEAKENS.  IT WILL REMAIN CLOUDY THOUGH WITH TEMPS IN THE 30S.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...

HIGHLIGHTS...

* INVERTED TROUGH WILL BRING RAIN/SNOW SHOWERS TO THE MASS EAST
  COASTLINE MONDAY INTO TUES MORNING.
* WEAK WAVE OF LOW PRESSURE MON NIGHT/TUESDAY COULD BRING WINTRY
  MIX TO INTERIOR
* ANOMALOUS SYSTEM ACROSS THE GREAT LAKES WILL BRING HEAVY
  RAIN...GUSTY WINDS AND COASTAL FLOODING CONCERNS AROUND CHRISTMAS
  EVE

OVERVIEW...

OVERALL 00Z GUIDANCE IS IN AGREEMENT SYNOPTICALLY WITH ISSUES ON
TIMING AND SMALLER SCALE FEATURES. IT REMAINS EVIDENT THAT AN
AMPLIFIED MID-UPPER LEVEL TROUGH AND PCPN FOCUSING LEAD SURFACE
LOW/FRONTAL SYSTEM WILL STEADILY PROGRESS TO THE EAST-CENTRAL U.S.
TUE AS EMBEDDED IMPULSES DIG TO THE LEE OF AN AMPLIFIED ERN
PACIFIC/WEST COAST RIDGE ALOFT. THE SUPPORTING AND INCREASINGLY
NEGATIVE-TILT TROUGH ALOFT WORKS OVER THE ERN US AND OUT THROUGH THE
NERN STATES INTO DAYS 4/5 WED/THU.  MODELS/ENSEMBLES HAVE BEEN
FAIRLY CONSISTENT ON THIS AMPLIFIED PATTERN AND THE MOST RECENT
GEFS/ECMWF ENSEMBLE GUIDANCE SHOW GOOD CORRELATION TO NEXT THURSDAY.

HIGH PRESSURE AND UPPER LEVEL RIDGE OVER THE REGION WILL BEGIN TO
EXIT BY MONDAY. AT THE SURFACE APPEARS ANOTHER INVERTED
TROUGH/ONSHORE FLOW WILL YIELD TO PRECIP ALONG THE MASS COASTLINE ON
MONDAY. ASIDE FROM THIS QUICK MESOSCALE EVENT THE MAIN FOCUS IS ON
THE LONGWAVE DIGGING TROUGH OVER THE CENTRAL CONUS WHICH WILL PUSH A
FEW SHORTWAVES THROUGH THE FLOW. FIRST ONE DEVELOPS A WEAK WAVE
MOVING TOWARDS THE REGION LATE MONDAY INTO TUESDAY. THERE IS STILL
SOME UNCERTAINTY WITH THE LOCATION/STRENGTH OF THIS SYSTEM BUT
APPEARS THAT THERE IS THE POSSIBILITY OF A SNOW/WINTRY MIX IN THE
INTERIOR. AS THIS SYSTEM DEPARTS AN ANOMALOUS LOW OVER THE GREAT
LAKES WILL DEVELOP A SECONDARY LOW JUST WEST OF SOUTHERN NEW ENGLAND
...PER ENSEMBLE GUIDANCE. STILL A SOME SPREAD BUT IF THIS DOUBLE LOW
DOES DEVELOP THEN THE RAIN AND WIND ASPECT OF THE SYSTEM
INCREASES...DETAILS BELOW. STILL NEED TO WORK OUT MINOR DETAILS WITH
THIS PARTICULAR SYSTEM BUT WITH 3 TO 4 STANDARD DEVIATIONS AWAY AND
GENERAL MODEL AGREEMENT HAVE HIGH CONFIDENCE THIS SYSTEM WILL IMPACT
SOUTHERN NEW ENGLAND.

DETAILS...

SUNDAY NIGHT INTO TUESDAY...MODERATE CONFIDENCE.

HIGH PRESSURE AND UPPER LEVEL RIDGE WILL BEGIN TO MOVE OFFSHORE AS
DIGGING TROUGH BEGINS TO SET-UP OVER THE CENTRAL CONUS. APPEARS
ANOTHER MESO-SCALE INVERTED TROUGH WILL SET UP ON MONDAY AND LAST
INTO EARLY TUESDAY MORNING. GUIDANCE SHOWS THAT RAIN/SNOW SHOWERS
WILL DEVELOP ALONG THE MASS EAST COASTLINE THANKS TO ONSHORE
EASTERLY FLOW. APPEARS THE COLUMN WILL SATURATE PER BUFKIT SOUNDINGS
AND SOUTHERLY FLOW ALOFT. BOTH THE NAM AND GFS SHOW QPF MAKING IT
ONSHORE DURING THIS TIME FRAME. HOWEVER THE EC IS SLIGHTLY SLOWER
AND KEEP THE BULK OF THE PRECIP JUST OFFSHORE. ADD A CHANCE OF POPS
DUE TO THE NAM/GFS MODEL CONTINUITY.

BY LATE MONDAY NIGHT INTO TUESDAY A SOUTHERN BRANCH STORM SYSTEM
FORMS ALONG THE SE COAST AND TAKES A TRACK OFF THE MID ATLANTIC
COAST. THIS SYSTEM GETS CAUGHT UP WITH THE OVERALL LARGE SCALE
AMPLIFICATION OF THE UPPER AIR PATTERN. THERE IS DECENT WARM
ADVECTION WITH COLD AIR DAMMING ACROSS THE INTERIOR. BIGGEST
QUESTION WILL BE IS THERE ENOUGH MOISTURE FOR PRECIP DURING THIS
TIME FRAME. IF PRECIP OVERRUNS THEN COULD SEE FREEZING RAIN/DRIZZLE
ACROSS THE INTERIOR LATE MONDAY INTO TUESDAY MORNING. DURING THE DAY
ON TUESDAY...GOOD AMOUNT OF WARM AIR WILL PUSH SURFACE TEMPS ABOVE
FREEZING ALLOWING FOR ANY PRECIP TO BE MORE OF THE LIQUID VARIETY
AHEAD OF THE CHRISTMAS EVE STORM. HOWEVER GUIDANCE IS ALWAYS TOO
FAST IN SCOURING TEMPS OUT ESP ACROSS THE CT VALLEY SO WE WILL NEED
TO MONITOR THIS CLOSELY...ESP DUE TO LIGHT WINDS AND THE HIGH IN
EASTERN CANADA.

WE COULD ALSO SEE SOME MINOR COASTAL FLOODING CONCERNS ON TUESDAY. SEE
BELOW FOR MORE DETAILS.

WEDNESDAY INTO THURSDAY...HIGH CONFIDENCE IN SYSTEM LOW CONFIDENCE
ON DETAILS.

STRONG ANOMALOUS SYSTEM WILL STRENGTHEN OVER THE GREAT
LAKES...DEVELOPING A POTENTIAL SECONDARY SURFACE LOW JUST WEST OF
SOUTHERN NEW ENGLAND. STILL A LOT OF DETAILS TO WORK OUT AS THIS
SYSTEM IS STILL 5 DAYS AWAY...HOWEVER ENSEMBLES CONTINUE TO SHOW
STRONG AGREEMENT SO HAVE INCREASING CONFIDENCE THAT A POTENT STORM
WILL OCCUR. LATEST 00Z GUIDANCE SHOWS THAT MOST PRECIP WILL BE
LIQUID WITH A DEEP SUBTROPICAL CONNECTION BACK ACROSS THE GULF OF
MEXICO...PW ANOMALIES FORECAST TO RISE BETWEEN +3 TO +4. CURRENT
PWATS ARE PROGGED ABOVE 1.6 INCHES SO HAVE CONTINUED THE CATEGORICAL
POPS. TEMPERATURES WILL BE WELL ABOVE AVERAGE...IN FACT WE MAY BE
CLOSE AT BREAKING RECORD HIGH TEMPS IF TEMPS WARM TO 60F OR ABOVE ON
CHRISTMAS EVE.  AS THE SYSTEM WRAPS UP INTO CANADA...COLD AIR
ADVECTION SHOULD CIRCULATE AROUND AND BEGIN A TRANSITION FROM
SOUTHWEST TO NORTHEAST IN TURNING P-TYPE TO SNOW. HOWEVER LATEST
GUIDANCE DOES SHOW A QUICK MOVING DRY SLOT SO SNOWFALL WILL STRUGGLE
DUE TO LACK OF MOISTURE.

THIS SYSTEM IS QUITE POTENT SO WE WILL NEED TO WATCH FOR POTENTIAL
HAZARDS. CURRENTLY THINK THAT WE COULD POSSIBLE URBAN FLOODING
ISSUES AS MODELS PROGGED WELL OVER 1.5 INCHES OF QPF. LATEST EC EVEN
SHOWS 2.5 INCHES OF QPF IS POSSIBLE. THE GEFS SHOW A MOISTURE FLUX
AT 850 MB BEING 4 TO 5 STANDARD DEVIATIONS AWAY...AND WITH THE
TROPICAL CONNECTION AND STRONG SOUTHERLY FLOW COULD SEE HIGHER
AMOUNTS DUE TO TOPOGRAPHY ENHANCEMENTS. RAIN FALL RECORDS MAY FALL
IF EVERYTHING FALLS INTO PLACE.

ALSO BELIEVE THAT WE MAY SEE SOME WIND ISSUES WITH THIS SYSTEM.
GUIDANCE RIGHT NOW IS SHOWING A 45 TO 55 KT JET AT 925 MB...HOWEVER
IT WILL BE HARD TO BREAK THE INVERSION WITH THE SOUTHERLY FLOW.
RIGHT NOW BELIEVE THAT WIND ADVISORIES MAY BE NEEDED BUT IF THIS
SYSTEM STRENGTHEN EVEN MORE SO A STRONGER JET IS POSSIBLE.

CONTINUED THE MENTIONED OF ISOLATED THUNDER IN THE FORECAST PER PREV
FORECASTER SUGGESTION. BELIEVE IT COULD BE POSSIBLE AS SOUTHERN NEW
ENGLAND WILL BE IN THE WARM SECTOR...WITH THE ANOMALOUS JET AND
SHOWALTERS CLOSE TO ZERO.

FRIDAY...LOW CONFIDENCE.

ONCE UPPER LEVEL LOW MOVES INTO SOUTHERN CANADA...EXPECT A RATHER
FAST UPPER W FLOW IN PLACE. MAY SEE LEFTOVER SNOW SHOWERS BUT TEMPS
WILL FALL BACK CLOSE TO SEASONAL NORMS.

&&

.AVIATION /10Z SATURDAY THROUGH WEDNESDAY/...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /THROUGH SUNDAY/...

430 AM UPDATE...

TODAY...MODERATE CONFIDENCE.  MVFR CIGS WILL CONTINUE TO OVERSPREAD
EASTERN NEW ENGLAND THIS MORNING AND EVENTUALLY INTO THE INTERIOR
THIS AFTERNOON.  SCATTERED PRECIPITATION WILL OVERSPREAD
SOUTHEAST MA/CAPE/ISLANDS THIS AFTERNOON.  PTYPE MAINLY SNOW SHOWERS
NORTHWEST OF THE SOUTHEAST PLYMOUTH COUNTY COAST AND RAIN SHOWERS
SOUTHEAST OF THAT REGION. LOCALIZED IFR CONDITIONS POSSIBLE JUST
INLAND FROM THE SOUTHEAST NEW ENGLAND COAST...WHERE PTYPE IS SNOW.

TONIGHT AND SUNDAY...MODERATE CONFIDENCE.  MVFR CONDITIONS DOMINATE
IN LOWER CLOUDS AND SCATTERED PRECIPITATION.  LOCALIZED IFR
CONDITIONS POSSIBLE WITH THE BEST CHANCE IN SNOW SHOWERS.
PRECIPITATION AFFECTS MAINLY EASTERN NEW ENGLAND BUT STILL SOME
SCATTERED ACTIVITY ACROSS WESTERN NEW ENGLAND. PTYPE MAINLY SNOW
SHOWERS NORTHWEST OF THE SOUTHEAST PLYMOUTH COUNTY COAST...WITH RAIN
SHOWERS SOUTHEAST OF THAT REGION.

KBOS TERMINAL...MODERATE CONFIDENCE IN TAF.  SNOW SHOWERS MAY ARRIVE
TOWARDS 00Z THIS EVENING.

KBDL TERMINAL...MODERATE CONFIDENCE IN TAF.

OUTLOOK...SUNDAY NIGHT THROUGH WEDNESDAY...

MONDAY INTO TUESDAY...MODERATE CONFIDENCE. EXPECT MOSTLY
VFR...ISOLATED MVFR ALONG THE MASS EAST COASTLINE IN RAIN/SNOW
SHOWERS.

TUESDAY NIGHT INTO WEDNESDAY...MODERATE CONFIDENCE. CONDITIONS WILL
BE DETERIORATING AS HEAVY DOWNPOURS...ISO THUNDER AND GUSTY SOUTHERLY
WINDS MOVE INTO THE REGION BY WEDNESDAY. COULD SEE MVFR TO IFR
CONDITIONS IN CIGS AND VSBYS.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /TODAY THROUGH SUNDAY/...HIGH CONFIDENCE.

HIGH PRESSURE ACROSS QUEBEC WILL RESULT IN PERSISTENT NORTHEAST
WINDS ACROSS THE WATERS THROUGH THE WEEKEND.  WIND GUSTS UP TO 20
KNOTS WITH SEAS BETWEEN 2 AND 4 FEET ARE EXPECTED FOR MOST
WATERS...SO NO HEADLINES PLANNED. THERE IS A LOW PROBABILITY THAT A
BRIEF SURGE OF NORTHEAST WIND GUSTS NEAR 25 KNOTS WITH MARGINAL 5
FOOT SEAS COULD AFFECT OUR NORTHERN WATERS LATE TONIGHT INTO SUN
MORNING...BUT NOT CONFIDENT ENOUGH TO ISSUE ANY HEADLINES AT THIS
POINT.

OUTLOOK...SUNDAY NIGHT INTO WEDNESDAY...MODERATE TO HIGH
CONFIDENCE.

SUNDAY INTO MONDAY. CONTINUOUS NORTHEAST FLOW WILL KEEP SEAS CHOPPY.
LINGERING NORTHEAST SWELL MAY BUMP SEAS ABOVE 5FT ESP ACROSS THE
NORTHEASTERN WATERS. SCA MAY BE NEEDED...BUT LOWER CONFIDENCE.

TUESDAY INTO WEDNESDAY...NE WINDS WILL INCREASE...GUSTING TO 30 KT
TUE THEN SHIFT TO SE GUSTING TO 30-35 KT WED...HIGHEST ON THE OUTER
WATERS. SEAS BUILD UP TO 7-11 FT BY WED. GALES WILL BE NEEDED.

&&

.TIDES/COASTAL FLOODING...

HIGH ASTRONOMICAL TIDES WILL OCCUR TUESDAY THROUGH THURSDAY. BREAKING
IT DOWN...ON TUESDAY HIGH TIDE AT BOSTON WILL BE 11.6 FT. THERE WILL
BE ONSHORE FLOW DURING THIS HIGH TIDE ALLOWING FOR MINOR SPLASHOVER.
IF WIND GUSTS INCREASE THEN COULD POSSIBLE SEE MINOR COASTAL
FLOODING.

ON WEDNESDAY...WINDS WILL SWITCH TO A MORE SOUTHEASTERLY FLOW DURING
THE DAY AND INCREASE QUICKLY FROM APPROACHING SYSTEM AND DESCENT
PRESSURE FALLS. WEDNESDAY AFTERNOON HIGH TIDE IN BOSTON IS 11.7 FT
AND WITH ANY STRENGTH ON THE EASTERLY WIND FLOW WILL PUSH THE TIDE
OVER. RIGHT NOW BELIEVE MINOR COASTAL FLOODING IS POSSIBLE ALONG THE
EAST COASTLINE. HOWEVER WEDNESDAY EVENING...THE WIND GOES IN A MORE
SOUTHERLY DIRECTION AND HIGH TIDE IN PROVIDENCE WILL BE 5.2 FT. 925
MB LLJ STRENGTHENS TO 50-60 KTS WHICH COULD PUSH A DESCENT SURGE UP
ALONG THE SOUTH COAST DURING THE TIME OF HIGH TIDE. THINKING THAT
MINOR COASTAL FLOODING COULD OCCUR BUT CANNOT RULE OUT MODERATE
ALONG THE SOUTH COAST...ESP IF LLJ STRENGTHENS EVEN MORE.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...FRANK/DUNTEN
NEAR TERM...FRANK
SHORT TERM...FRANK
LONG TERM...DUNTEN
AVIATION...FRANK/DUNTEN
MARINE...FRANK/DUNTEN
TIDES/COASTAL FLOODING...DUNTEN




000
FXUS61 KBOX 200608
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
107 AM EST SAT DEC 20 2014

.SYNOPSIS...
A WEAK DISTURBANCE AND ONSHORE FLOW WILL RESULT IN A PERIOD OF
LIGHT SNOW/RAIN SHOWERS MAINLY ACROSS EASTERN NEW ENGLAND THIS
WEEKEND INTO EARLY NEXT WEEK. LOW PRESSURE WILL PASS SOUTH OF NEW
ENGLAND...BRINGING ANOTHER PERIOD OF PRECIPITATION. A MUCH
STRONGER STORM PASSING WEST OF NEW ENGLAND WILL BRING HEAVY
RAINFALL...GUSTY WINDS AND COASTAL FLOODING CONCERNS TO THE
REGION WEDNESDAY INTO WEDNESDAY EVENING. DRY BUT VERY WINDY
CONDITIONS FOLLOW FOR CHRISTMAS DAY INTO FRIDAY.

&&

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

105 AM UPDATE...

LOW CLOUDS BEGINNING TO BACK IN OFF THE OCEAN VERY EARLY THIS
MORNING.  THIS IN RESPONSE TO AN APPROACHING SHORTWAVE RESULTING IN
WINDS AT 925 MB BECOMING EAST.  SHOULD SEE LOW CLOUDS CONTINUE TO
EXPAND ACROSS EASTERN NEW ENGLAND THROUGH DAYBREAK...WHILE THE
INTERIOR HAS CLEAR TO PARTLY CLOUDY SKIES.  TEMPS WILL REMAIN IN THE
20S THROUGH DAYBREAK...EXCEPT LOWER TO MIDDLE 30S ACROSS PORTIONS OF
THE CAPE/ACK WITH AN ONSHORE COMPONENT TO THE WIND.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SUNDAY/...
HIGH PRES BUILDS ACROSS N MAINE AND THE MARITIMES WITH LOW LEVEL
FLOW VEERING TO THE E WHILE SFC WINDS MOSTLY NE. THIS WILL RESULT
IN LOW CLOUDS EXPANDING WEST ACROSS SNE DURING SAT AS LOW LEVEL
MOISTURE INCREASES. NOT REALLY LOOKING AT A PURE OCEAN EFFECT
SITUATION AS INSTABILITY IS MARGINAL. HOWEVER...HI-RES GUIDANCE
PICKING UP ON A DEVELOPING COASTAL FRONT ACROSS CAPE COD VICINITY
WITH E WINDS TO THE E OF THE BOUNDARY AND N/NE WINDS TO THE WEST.
LOW LEVEL FORCING COMBINED WITH DEEPENING MOISTURE AS MID LEVEL
SHORTWAVE MOVES IN FROM THE WEST WILL RESULT IN RAIN/SNOW SHOWERS
EXPANDING WEST FROM CAPE COD INTO EASTERN HALF NEW ENG. WHILE SOME
LIGHT PRECIP IS POSSIBLE IN THE MORNING...ESPECIALLY CAPE
COD...BULK OF PRECIP OCCURS LATER SAT INTO SAT NIGHT ASSOCD WITH
DEEPER MOISTURE AND LOW LEVEL LIFT FROM THE COASTAL FRONT/INVERTED
TROF.

PTYPE/SNOW ACCUM...
LOOKING AT MOSTLY RAIN FOR CAPE/ISLANDS AND POSSIBLY INTO SE
COASTAL PLYMOUTH COUNTY WHERE E WINDS WILL SUFFICIENTLY WARM THE
BOUNDARY LAYER KEEPING TEMPS IN THE MID/UPPER 30S. HOWEVER...JUST
INLAND AND NORTH FROM THE IMMEDIATE SE COAST AND WEST OF THE
COASTAL FRONT WHERE WINDS ARE FORECAST TO BE MORE
NORTHERLY...EXPECT MOSTLY SNOW ALTHOUGH THERE COULD BE A MIX AT
THE START. FREEZING DRIZZLE IS NOT LIKELY AS THE COLUMN MOISTENS
LATE SAT INTO SAT NIGHT WITH TEMPS -10C IN THE MOIST LAYER WHICH
IS COLD ENOUGH FOR ICE CRYSTAL PRODUCTION.

NAM IS PICKING UP ON SOME ENHANCEMENT IN N PLYMOUTH COUNTY INTO
NORFOLK COUNTY WITH QPF UP TO A THIRD OF AN INCH. THIS LIKELY
ASSOCD WITH A 20-25 KT E/NE LOW LEVEL JET THAT THE NAM IS
FORECASTING. HOWEVER...THIS MIGHT BE OVERDONE AS HI-RES WRF QPF
IS LESS AND OTHER MODELS ARE WEAKER WITH THE LOW LEVEL NE FLOW.
DONT WANT TO COMPLETELY IGNORE THE NAM AS IT SOMETIMES CAN PICK
UP ON HEAVIER MESOSCALE PRECIP IN THESE SITUATIONS SO USED A
BLEND OF NAM/GFS QPF TO TEMPER NAM OUTPUT. MAINLY LOOKING AT A
COATING TO AN INCH FOR EASTERN NEW ENG...HIGHEST AMOUNTS ACROSS E
MA AWAY FROM THE IMMEDIATE COAST. LOCALIZED AMOUNTS UP TO 2 INCHES
POSSIBLE...ESPECIALLY JUST SW OF BOSTON.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
HIGHLIGHTS...

* SCT SNOW/RAIN SHOWERS LINGER ON SUNDAY WITH SLIGHTLY BELOW
  NORMAL TEMPS
* WEAK LOW PRES WILL PASS SOUTH OF NEW ENGLAND MONDAY NIGHT AND
  TUESDAY BRINGING LIGHT PRECIPITATION...AS WELL AS A WINTRY MIX
  TO THE INTERIOR
* STRENGTHENING LOW PRES WILL WRAP UP AROUND ANOMALOUS VORTEX
  ACROSS THE GREAT LAKES...BRINGING HEAVY RAIN...GUSTY WINDS AND
  COASTAL CONCERNS TO THE REGION LATE WEDNESDAY INTO CHRISTMAS EVE

OVERVIEW AND MODEL PREFERENCES...

MEDIUM RANGE MODEL SUITE CONTINUES TO SIGNAL DEVELOPMENT OF
AMPLIFIED UPPER LEVEL PATTERN ACROSS NORTH AMERICA THROUGH THIS
FORECAST PERIOD. AN H5 CUTOFF VORTEX WILL DOMINATE ACROSS THE GREAT
LAKES AND ITS EXTENDING LONG WAVE TROUGH WRAPPING AROUND TO THE
EASTERN SEABOARD AS IT BECOMES NEGATIVELY TILTED. WITH OVERALL SW
FLOW IN PLACE...WILL SEE WEAK SYSTEMS WORK TOWARD THE REGION EARLY
IN THE PERIOD. A STRONGER LOW WILL DEVELOP NEAR OR JUST OFF THE SE
U.S. COAST AROUND EARLY WED AND PASS W OF THE REGION WED NIGHT...
BRINGING GUSTY WINDS...HEAVY RAINFALL WITH A FEW THUNDERSTORMS
POSSIBLE AS WELL AS POSSIBLE COASTAL CONCERNS.

WHILE THERE ARE STILL SOME TIMING AND TRACK VARIANCES WITH THE MID
WEEK SYSTEM...MODELS AND ENSEMBLES REMAIN IN GOOD AGREEMENT WITH THE
DEVELOPMENT OF THIS AMPLIFIED PATTERN...AS WELL AS THE UPPER
LEVEL VORTEX ACROSS THE GREAT LAKES AND SURFACE SYSTEM THAT WILL
MORE THAN LIKELY AFFECT THE REGION DURING THE WEDNESDAY-WEDNESDAY
NIGHT TIMEFRAME.

USED A BLEND OF AVAILABLE GUIDANCE AS WELL AS GFS/EC ENSEMBLE MEANS
FOR THIS FORECAST WHICH SHOWED GOOD CONTINUITY TO THE PREVIOUS
FORECAST.

DETAILS...

SUNDAY AND MONDAY...MODERATE TO HIGH CONFIDENCE.

LEFTOVER MOISTURE WILL LINGER SUNDAY MORNING WITH LIGHT RAIN
AND/OR SNOW SHOWERS MAINLY ACROSS E MA/RI THOUGH COULD SEE SOME
ISOLD ACTIVITY FURTHER INLAND AS COASTAL FRONT WEAKENS. RIDGING
WILL NOSE DOWN THE COAST FROM HIGH PRES OVER NORTHERN NEW ENGLAND
AND QUEBEC SUN NIGHT INTO MONDAY...BRINGING A BRIEF DRY PERIOD
THOUGH CLOUDS WILL LINGER WITH A CONTINUED ONSHORE WIND
FLOW...ALBEIT WEAK. EXPECT TEMPS TO RUN NEAR OR SLIGHTLY BELOW
NORMAL...THOUGH WILL BE A BIT MILDER ALONG THE S COAST DURING MON.

BY LATE MONDAY...MAY START TO SEE SOME PRECIP WORK INTO THE LOWER
CT VALLEY AS A WEAK LOW MOVES OFF THE MID ATLC COAST.

MONDAY NIGHT-TUESDAY...MODERATE CONFIDENCE.

WEAK COASTAL LOW WILL PASS OFF THE SOUTH COAST...BUT WILL BRING
ENOUGH MOISTURE AND LIFT FOR PRECIP TO MOVE IN FROM S-N. TEMPS
WILL STILL BE CHILLY THOUGH...ESPECIALLY INLAND THERE THE COLDER
AIR WILL BE TRAPPED... SO WILL SEE SOME MIXED PRECIP /SLEET AND/OR
FREEZING RAIN/. EVEN THOUGH QPF WILL BE LIGHT...COULD BE ENOUGH TO
CAUSE SOME LIGHT GLAZING PROBLEMS LATE MON NIGHT INTO TUE MORNING.
STILL SOME TIMING ISSUES AS WELL AS QUESTIONS WITH THERMAL
PROFILES...BUT MAY NEED WINTER WX HEADLINES DURING THIS TIMEFRAME.
SOMETHING TO MONITOR CLOSELY.

BY TUE AFTERNOON...TEMPS SHOULD RECOVER WITH GRADUALLY INCREASING
E-SE WINDS...SO WILL SEE ALL RAIN BY THEN. HIGHS ON TUE WILL
RANGE FROM THE UPPER 30S ACROSS THE HIGHER INLAND TERRAIN TO THE
MID AND UPPER 40S ALONG THE COAST.

ONE OTHER ISSUE THAT MAY NEED ATTENTION WILL BE THE LONG EASTERLY
FETCH AND INCREASING ASTRONOMICAL TIDES ON TUESDAY. BOSTON
HARBOR/S HIGH TIDE OCCURS AT 1142 AM AT 11.6 FEET. SURFACE WINDS
LOOK TO REMAIN AT 15 KT OR LESS BUT...WITH THE MAINLY EASTERLY
WIND DIRECTION OVER SEVERAL DAYS...MAY SEE SOME GROUND SWELLS WORK
IN WHICH COULD CAUSE SOME POSSIBLE SPLASHOVER DURING THE MIDDAY
TIDE.

WEDNESDAY AND THURSDAY...HIGH CONFIDENCE IN SYSTEM DEVELOPMENT AND
EFFECTS...LOW TO MODERATE CONFIDENCE ON TIMING DETAILS.

WILL SEE STRONG SURFACE SYSTEM AND ITS ASSOCIATED H5 CUTOFF
VORTEX WILL BE INTENSIFYING DURING THIS TIMEFRAME...WHILE LONG
WAVE TROUGHING WILL BECOME NEGATIVELY TILTED AROUND THE MID ATLC
OR SE U.S. COAST. A SECONDARY LOW...WITH ENERGY AND TROPICAL
MOISTURE WORKING IN FROM THE GULF OF MEXICO...WILL INTENSIFY
DURING WED AS IT WRAPS AROUND THE LARGER UPPER LEVEL CIRCULATION.
LOOKS LIKE THIS LOW WILL PASS W OF THE REGION...BUT WILL BE IN THE
AREA OF BEST MOISTURE CONVERGENCE AND TRANSPORT UP THE EASTERN
SEABOARD. THE 12Z GFS IS BULLISH IN BRINGING SLUG OF HEAVY QPF
ACROSS THE REGION. BOTH THE 12Z EC AND GGEM ALSO SIGNAL THIS
INFLUX THOUGH NOT QUITE AS HIGH ON THE PRECIP AMTS.

STILL NOTING PWATS AT 1.4 TO 1.5 INCHES...RUNNING 2-3SD ABOVE
SEASONAL NORMALS AT ABOUT THE TIME OF THE HEAVIEST PRECIP LATE
WED INTO WED EVENING. ON TOP OF THIS...SOME GOOD INSTABILITY MOVES
ACROSS WITH K INDICES IN THE LOWER-MID 30S AND TOTAL TOTALS IN THE
LOWER 50S. WOULD NOT BE SURPRISED TO SEE SOME ISOLD THUNDER SO
MENTIONED IN THE FORECAST MAINLY DURING WED NIGHT...ALONG WITH
HEAVY RAINFALL FROM THE CONVECTION. LOW LEVEL JET ON ORDER OF
40-55 KT AT H85 AND 50-60 KT AT H925...SO COULD ALSO SEE GUSTY
WINDS ESPECIALLY WITH ANY STORMS. OH...ONE MORE THING...THERE
WILL BE A BRIEF BURST OF MILDER AIR THAT WORKS IN WITH THIS
SYSTEM. EXPECT TEMPS TO RISE TO THE MID 40S WELL INLAND TO THE
MID 50S AT THE COAST...BUT WILL NOT TOP OFF UNTIL CLOSE TO
MIDNIGHT WED NIGHT...WHICH WILL HELP SUPPORT THE INSTABILITY.

MODELS CONTINUE TO SIGNAL FAST MOVEMENT OF THE SURFACE SYSTEM
LATE WED NIGHT...WITH DRY SLOT WORKING ACROSS THE REGION AFTER
MIDNIGHT WITH DRY CONDITIONS BY DAWN ON CHRISTMAS MORNING. WINDS
WILL QUICKLY SHIFT AROUND TO W-SW AND WILL BECOME VERY GUSTY WITH
THE LOW LEVEL JET IN PLACE AND COLDER AIR WRAPPING IN.

MAY HAVE SOME COASTAL FLOODING ISSUES WITH HIGHEST ASTRONOMICAL
TIDES OF THE MONTH OCCUR ON WED AND THU...UP TO 11.7 FT AND 11.5
FT RESPECTIVELY FOR BOSTON. ANY EASTERLY COMPONENT WILL PUSH THE
TIDE ABOVE FLOOD...SO COASTAL FLOODING IS POSSIBLE AS WELL AS
BEACH EROSION ON THE WED TIDE ALONG E FACING BEACHES. THE SOUTH
COASTLINE WILL ALSO HAVE TO BE WATCH CLOSELY ON THU AS WINDS SHIFT
TO W- SW...THOUGH E COASTAL AREAS COULD SEE PROBLEMS WITH
CONTINUED E SWELLS. AS MENTIONED ABOVE...STRONG SOUTHERLY JET
DEVELOPS WED INTO THU AND...WITH ASTRONOMICAL HIGH TIDES...COULD
ALSO SEE MINOR TO MODERATE COASTAL FLOODING. ANOTHER ISSUE IS THE
POTENTIAL PRESSURE FALLS IF THIS SYSTEM STRENGTHENS EVEN
MORE...IT COULD ADD ANOTHER FOOT ONTO THE SURGE.

FRIDAY...LOW CONFIDENCE.

ONCE UPPER LOW AND SURFACE SYSTEM MOVES INTO SOUTHERN CANADA...
EXPECT A RATHER FAST UPPER W FLOW IN PLACE. MAY SEE SOME LEFTOVER
SNOW SHOWERS ACROSS THE E SLOPES OF THE BERKSHIRES. GUSTY W-SW
WINDS CONTINUE AS TEMPS FALL BACK TO MORE SEASONABLE LEVELS.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...

FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /THROUGH SUNDAY/...

105 AM UPDATE...

TODAY...MODERATE CONFIDENCE.  MVFR CIGS WILL CONTINUE TO OVERSPREAD
EASTERN NEW ENGLAND THIS MORNING AND EVENTUALLY INTO THE INTERIOR
THIS AFTERNOON.  SCATTERED PRECIPITATION WILL OVERSPREAD
SOUTHEAST MA/CAPE/ISLANDS THIS AFTERNOON.  PTYPE MAINLY SNOW SHOWERS
NORTHWEST OF THE SOUTHEAST PLYMOUTH COUNTY COAST AND RAIN SHOWERS
SOUTHEAST OF THAT REGION. LOCALIZED IFR CONDITIONS POSSIBLE JUST
INLAND FROM THE SOUTHEAST NEW ENGLAND COAST...WHERE PTYPE IS SNOW.

TONIGHT AND SUNDAY...MODERATE CONFIDENCE.  MVFR CONDITIONS DOMINATE
IN LOWER CLOUDS AND SCATTERED PRECIPITATION.  LOCALIZED IFR
CONDITIONS POSSIBLE WITH THE BEST CHANCE IN SNOW SHOWERS.
PRECIPITATION AFFECTS MAINLY EASTERN NEW ENGLAND BUT STILL SOME
SCATTERED ACTIVITY ACROSS WESTERN NEW ENGLAND. PTYPE MAINLY SNOW
SHOWERS NORTHWEST OF THE SOUTHEAST PLYMOUTH COUNTY COAST AND RAIN
SHOWERS SOUTHEAST OF THAT REGION.

KBOS TERMINAL...MODERATE CONFIDENCE IN TAF.  SNOW SHOWERS MAY ARRIVE
TOWARDS 00Z THIS EVENING.

KBDL TERMINAL...MODERATE CONFIDENCE IN TAF.

OUTLOOK...SUNDAY NIGHT THROUGH WEDNESDAY...

MONDAY...MODERATE CONFIDENCE. MAINLY VFR.

MONDAY NIGHT-TUESDAY...MODERATE CONFIDENCE. DEVELOPING RAIN OR
MIXED PRECIP FROM S-N MON NIGHT WITH MVFR CONDITIONS. MAY SEE
-FZRA/-PL ACROSS CENTRAL AND WESTERN AREAS AROUND OR AFTER
MIDNIGHT INTO TUE MORNING THEN SHOULD CHANGE TO RAIN AS TEMPS
RISE. E-SE WINDS GUSTING TO 20-25 KT ALONG S COAST TUE.

TUESDAY NIGHT-WEDNESDAY...MODERATE CONFIDENCE. MVFR-IFR
CONDITIONS IN RAIN...HEAVY AT TIMES DURING WED. ISOLD THUNDER
POSSIBLE WED AFTERNOON/EVENING. E WINDS SHIFTING TO SE-S LATE TUE
NIGHT/WED WITH GUSTS UP TO 25-30 KT...HIGHEST ACROSS CAPE COD AND
THE ISLANDS.

&&

.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.

HIGH PRESSURE BUILDING EAST TO MAINE AND THE MARITIMES WILL KEEP
WINDS/SEAS BELOW SCA THRESHOLDS THROUGH SATURDAY NIGHT...WITH WIND
SPEEDS LESS THAN 20 KT. NORTHERLY WINDS TONIGHT BECOMING NE
SAT/SAT NIGHT. GUSTS UP TO 20 KT POSSIBLE SAT NIGHT ACROSS NE MA
COASTAL WATERS.

OUTLOOK...SUNDAY THROUGH WEDNESDAY...MODERATE TO HIGH CONFIDENCE.

SUNDAY THROUGH MONDAY NIGHT...WINDS AND SEAS BELOW SMALL CRAFT
CRITERIA. E WINDS GUSTING UP TO 20 KT MON NIGHT.

TUESDAY-WEDNESDAY...E WINDS INCREASE...GUSTING TO 30 KT TUE THEN
SHIFT TO SE GUSTING TO 30-35 KT WED...HIGHEST ON THE OUTER
WATERS. SEAS BUILD UP TO 7-11 FT BY WED. GALES ON THE OUTER WATERS
LIKELY.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...KJC/EVT
NEAR TERM...FRANK
SHORT TERM...KJC
LONG TERM...EVT
AVIATION...FRANK/EVT
MARINE...KJC/EVT





000
FXUS61 KBOX 200608
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
107 AM EST SAT DEC 20 2014

.SYNOPSIS...
A WEAK DISTURBANCE AND ONSHORE FLOW WILL RESULT IN A PERIOD OF
LIGHT SNOW/RAIN SHOWERS MAINLY ACROSS EASTERN NEW ENGLAND THIS
WEEKEND INTO EARLY NEXT WEEK. LOW PRESSURE WILL PASS SOUTH OF NEW
ENGLAND...BRINGING ANOTHER PERIOD OF PRECIPITATION. A MUCH
STRONGER STORM PASSING WEST OF NEW ENGLAND WILL BRING HEAVY
RAINFALL...GUSTY WINDS AND COASTAL FLOODING CONCERNS TO THE
REGION WEDNESDAY INTO WEDNESDAY EVENING. DRY BUT VERY WINDY
CONDITIONS FOLLOW FOR CHRISTMAS DAY INTO FRIDAY.

&&

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

105 AM UPDATE...

LOW CLOUDS BEGINNING TO BACK IN OFF THE OCEAN VERY EARLY THIS
MORNING.  THIS IN RESPONSE TO AN APPROACHING SHORTWAVE RESULTING IN
WINDS AT 925 MB BECOMING EAST.  SHOULD SEE LOW CLOUDS CONTINUE TO
EXPAND ACROSS EASTERN NEW ENGLAND THROUGH DAYBREAK...WHILE THE
INTERIOR HAS CLEAR TO PARTLY CLOUDY SKIES.  TEMPS WILL REMAIN IN THE
20S THROUGH DAYBREAK...EXCEPT LOWER TO MIDDLE 30S ACROSS PORTIONS OF
THE CAPE/ACK WITH AN ONSHORE COMPONENT TO THE WIND.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SUNDAY/...
HIGH PRES BUILDS ACROSS N MAINE AND THE MARITIMES WITH LOW LEVEL
FLOW VEERING TO THE E WHILE SFC WINDS MOSTLY NE. THIS WILL RESULT
IN LOW CLOUDS EXPANDING WEST ACROSS SNE DURING SAT AS LOW LEVEL
MOISTURE INCREASES. NOT REALLY LOOKING AT A PURE OCEAN EFFECT
SITUATION AS INSTABILITY IS MARGINAL. HOWEVER...HI-RES GUIDANCE
PICKING UP ON A DEVELOPING COASTAL FRONT ACROSS CAPE COD VICINITY
WITH E WINDS TO THE E OF THE BOUNDARY AND N/NE WINDS TO THE WEST.
LOW LEVEL FORCING COMBINED WITH DEEPENING MOISTURE AS MID LEVEL
SHORTWAVE MOVES IN FROM THE WEST WILL RESULT IN RAIN/SNOW SHOWERS
EXPANDING WEST FROM CAPE COD INTO EASTERN HALF NEW ENG. WHILE SOME
LIGHT PRECIP IS POSSIBLE IN THE MORNING...ESPECIALLY CAPE
COD...BULK OF PRECIP OCCURS LATER SAT INTO SAT NIGHT ASSOCD WITH
DEEPER MOISTURE AND LOW LEVEL LIFT FROM THE COASTAL FRONT/INVERTED
TROF.

PTYPE/SNOW ACCUM...
LOOKING AT MOSTLY RAIN FOR CAPE/ISLANDS AND POSSIBLY INTO SE
COASTAL PLYMOUTH COUNTY WHERE E WINDS WILL SUFFICIENTLY WARM THE
BOUNDARY LAYER KEEPING TEMPS IN THE MID/UPPER 30S. HOWEVER...JUST
INLAND AND NORTH FROM THE IMMEDIATE SE COAST AND WEST OF THE
COASTAL FRONT WHERE WINDS ARE FORECAST TO BE MORE
NORTHERLY...EXPECT MOSTLY SNOW ALTHOUGH THERE COULD BE A MIX AT
THE START. FREEZING DRIZZLE IS NOT LIKELY AS THE COLUMN MOISTENS
LATE SAT INTO SAT NIGHT WITH TEMPS -10C IN THE MOIST LAYER WHICH
IS COLD ENOUGH FOR ICE CRYSTAL PRODUCTION.

NAM IS PICKING UP ON SOME ENHANCEMENT IN N PLYMOUTH COUNTY INTO
NORFOLK COUNTY WITH QPF UP TO A THIRD OF AN INCH. THIS LIKELY
ASSOCD WITH A 20-25 KT E/NE LOW LEVEL JET THAT THE NAM IS
FORECASTING. HOWEVER...THIS MIGHT BE OVERDONE AS HI-RES WRF QPF
IS LESS AND OTHER MODELS ARE WEAKER WITH THE LOW LEVEL NE FLOW.
DONT WANT TO COMPLETELY IGNORE THE NAM AS IT SOMETIMES CAN PICK
UP ON HEAVIER MESOSCALE PRECIP IN THESE SITUATIONS SO USED A
BLEND OF NAM/GFS QPF TO TEMPER NAM OUTPUT. MAINLY LOOKING AT A
COATING TO AN INCH FOR EASTERN NEW ENG...HIGHEST AMOUNTS ACROSS E
MA AWAY FROM THE IMMEDIATE COAST. LOCALIZED AMOUNTS UP TO 2 INCHES
POSSIBLE...ESPECIALLY JUST SW OF BOSTON.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
HIGHLIGHTS...

* SCT SNOW/RAIN SHOWERS LINGER ON SUNDAY WITH SLIGHTLY BELOW
  NORMAL TEMPS
* WEAK LOW PRES WILL PASS SOUTH OF NEW ENGLAND MONDAY NIGHT AND
  TUESDAY BRINGING LIGHT PRECIPITATION...AS WELL AS A WINTRY MIX
  TO THE INTERIOR
* STRENGTHENING LOW PRES WILL WRAP UP AROUND ANOMALOUS VORTEX
  ACROSS THE GREAT LAKES...BRINGING HEAVY RAIN...GUSTY WINDS AND
  COASTAL CONCERNS TO THE REGION LATE WEDNESDAY INTO CHRISTMAS EVE

OVERVIEW AND MODEL PREFERENCES...

MEDIUM RANGE MODEL SUITE CONTINUES TO SIGNAL DEVELOPMENT OF
AMPLIFIED UPPER LEVEL PATTERN ACROSS NORTH AMERICA THROUGH THIS
FORECAST PERIOD. AN H5 CUTOFF VORTEX WILL DOMINATE ACROSS THE GREAT
LAKES AND ITS EXTENDING LONG WAVE TROUGH WRAPPING AROUND TO THE
EASTERN SEABOARD AS IT BECOMES NEGATIVELY TILTED. WITH OVERALL SW
FLOW IN PLACE...WILL SEE WEAK SYSTEMS WORK TOWARD THE REGION EARLY
IN THE PERIOD. A STRONGER LOW WILL DEVELOP NEAR OR JUST OFF THE SE
U.S. COAST AROUND EARLY WED AND PASS W OF THE REGION WED NIGHT...
BRINGING GUSTY WINDS...HEAVY RAINFALL WITH A FEW THUNDERSTORMS
POSSIBLE AS WELL AS POSSIBLE COASTAL CONCERNS.

WHILE THERE ARE STILL SOME TIMING AND TRACK VARIANCES WITH THE MID
WEEK SYSTEM...MODELS AND ENSEMBLES REMAIN IN GOOD AGREEMENT WITH THE
DEVELOPMENT OF THIS AMPLIFIED PATTERN...AS WELL AS THE UPPER
LEVEL VORTEX ACROSS THE GREAT LAKES AND SURFACE SYSTEM THAT WILL
MORE THAN LIKELY AFFECT THE REGION DURING THE WEDNESDAY-WEDNESDAY
NIGHT TIMEFRAME.

USED A BLEND OF AVAILABLE GUIDANCE AS WELL AS GFS/EC ENSEMBLE MEANS
FOR THIS FORECAST WHICH SHOWED GOOD CONTINUITY TO THE PREVIOUS
FORECAST.

DETAILS...

SUNDAY AND MONDAY...MODERATE TO HIGH CONFIDENCE.

LEFTOVER MOISTURE WILL LINGER SUNDAY MORNING WITH LIGHT RAIN
AND/OR SNOW SHOWERS MAINLY ACROSS E MA/RI THOUGH COULD SEE SOME
ISOLD ACTIVITY FURTHER INLAND AS COASTAL FRONT WEAKENS. RIDGING
WILL NOSE DOWN THE COAST FROM HIGH PRES OVER NORTHERN NEW ENGLAND
AND QUEBEC SUN NIGHT INTO MONDAY...BRINGING A BRIEF DRY PERIOD
THOUGH CLOUDS WILL LINGER WITH A CONTINUED ONSHORE WIND
FLOW...ALBEIT WEAK. EXPECT TEMPS TO RUN NEAR OR SLIGHTLY BELOW
NORMAL...THOUGH WILL BE A BIT MILDER ALONG THE S COAST DURING MON.

BY LATE MONDAY...MAY START TO SEE SOME PRECIP WORK INTO THE LOWER
CT VALLEY AS A WEAK LOW MOVES OFF THE MID ATLC COAST.

MONDAY NIGHT-TUESDAY...MODERATE CONFIDENCE.

WEAK COASTAL LOW WILL PASS OFF THE SOUTH COAST...BUT WILL BRING
ENOUGH MOISTURE AND LIFT FOR PRECIP TO MOVE IN FROM S-N. TEMPS
WILL STILL BE CHILLY THOUGH...ESPECIALLY INLAND THERE THE COLDER
AIR WILL BE TRAPPED... SO WILL SEE SOME MIXED PRECIP /SLEET AND/OR
FREEZING RAIN/. EVEN THOUGH QPF WILL BE LIGHT...COULD BE ENOUGH TO
CAUSE SOME LIGHT GLAZING PROBLEMS LATE MON NIGHT INTO TUE MORNING.
STILL SOME TIMING ISSUES AS WELL AS QUESTIONS WITH THERMAL
PROFILES...BUT MAY NEED WINTER WX HEADLINES DURING THIS TIMEFRAME.
SOMETHING TO MONITOR CLOSELY.

BY TUE AFTERNOON...TEMPS SHOULD RECOVER WITH GRADUALLY INCREASING
E-SE WINDS...SO WILL SEE ALL RAIN BY THEN. HIGHS ON TUE WILL
RANGE FROM THE UPPER 30S ACROSS THE HIGHER INLAND TERRAIN TO THE
MID AND UPPER 40S ALONG THE COAST.

ONE OTHER ISSUE THAT MAY NEED ATTENTION WILL BE THE LONG EASTERLY
FETCH AND INCREASING ASTRONOMICAL TIDES ON TUESDAY. BOSTON
HARBOR/S HIGH TIDE OCCURS AT 1142 AM AT 11.6 FEET. SURFACE WINDS
LOOK TO REMAIN AT 15 KT OR LESS BUT...WITH THE MAINLY EASTERLY
WIND DIRECTION OVER SEVERAL DAYS...MAY SEE SOME GROUND SWELLS WORK
IN WHICH COULD CAUSE SOME POSSIBLE SPLASHOVER DURING THE MIDDAY
TIDE.

WEDNESDAY AND THURSDAY...HIGH CONFIDENCE IN SYSTEM DEVELOPMENT AND
EFFECTS...LOW TO MODERATE CONFIDENCE ON TIMING DETAILS.

WILL SEE STRONG SURFACE SYSTEM AND ITS ASSOCIATED H5 CUTOFF
VORTEX WILL BE INTENSIFYING DURING THIS TIMEFRAME...WHILE LONG
WAVE TROUGHING WILL BECOME NEGATIVELY TILTED AROUND THE MID ATLC
OR SE U.S. COAST. A SECONDARY LOW...WITH ENERGY AND TROPICAL
MOISTURE WORKING IN FROM THE GULF OF MEXICO...WILL INTENSIFY
DURING WED AS IT WRAPS AROUND THE LARGER UPPER LEVEL CIRCULATION.
LOOKS LIKE THIS LOW WILL PASS W OF THE REGION...BUT WILL BE IN THE
AREA OF BEST MOISTURE CONVERGENCE AND TRANSPORT UP THE EASTERN
SEABOARD. THE 12Z GFS IS BULLISH IN BRINGING SLUG OF HEAVY QPF
ACROSS THE REGION. BOTH THE 12Z EC AND GGEM ALSO SIGNAL THIS
INFLUX THOUGH NOT QUITE AS HIGH ON THE PRECIP AMTS.

STILL NOTING PWATS AT 1.4 TO 1.5 INCHES...RUNNING 2-3SD ABOVE
SEASONAL NORMALS AT ABOUT THE TIME OF THE HEAVIEST PRECIP LATE
WED INTO WED EVENING. ON TOP OF THIS...SOME GOOD INSTABILITY MOVES
ACROSS WITH K INDICES IN THE LOWER-MID 30S AND TOTAL TOTALS IN THE
LOWER 50S. WOULD NOT BE SURPRISED TO SEE SOME ISOLD THUNDER SO
MENTIONED IN THE FORECAST MAINLY DURING WED NIGHT...ALONG WITH
HEAVY RAINFALL FROM THE CONVECTION. LOW LEVEL JET ON ORDER OF
40-55 KT AT H85 AND 50-60 KT AT H925...SO COULD ALSO SEE GUSTY
WINDS ESPECIALLY WITH ANY STORMS. OH...ONE MORE THING...THERE
WILL BE A BRIEF BURST OF MILDER AIR THAT WORKS IN WITH THIS
SYSTEM. EXPECT TEMPS TO RISE TO THE MID 40S WELL INLAND TO THE
MID 50S AT THE COAST...BUT WILL NOT TOP OFF UNTIL CLOSE TO
MIDNIGHT WED NIGHT...WHICH WILL HELP SUPPORT THE INSTABILITY.

MODELS CONTINUE TO SIGNAL FAST MOVEMENT OF THE SURFACE SYSTEM
LATE WED NIGHT...WITH DRY SLOT WORKING ACROSS THE REGION AFTER
MIDNIGHT WITH DRY CONDITIONS BY DAWN ON CHRISTMAS MORNING. WINDS
WILL QUICKLY SHIFT AROUND TO W-SW AND WILL BECOME VERY GUSTY WITH
THE LOW LEVEL JET IN PLACE AND COLDER AIR WRAPPING IN.

MAY HAVE SOME COASTAL FLOODING ISSUES WITH HIGHEST ASTRONOMICAL
TIDES OF THE MONTH OCCUR ON WED AND THU...UP TO 11.7 FT AND 11.5
FT RESPECTIVELY FOR BOSTON. ANY EASTERLY COMPONENT WILL PUSH THE
TIDE ABOVE FLOOD...SO COASTAL FLOODING IS POSSIBLE AS WELL AS
BEACH EROSION ON THE WED TIDE ALONG E FACING BEACHES. THE SOUTH
COASTLINE WILL ALSO HAVE TO BE WATCH CLOSELY ON THU AS WINDS SHIFT
TO W- SW...THOUGH E COASTAL AREAS COULD SEE PROBLEMS WITH
CONTINUED E SWELLS. AS MENTIONED ABOVE...STRONG SOUTHERLY JET
DEVELOPS WED INTO THU AND...WITH ASTRONOMICAL HIGH TIDES...COULD
ALSO SEE MINOR TO MODERATE COASTAL FLOODING. ANOTHER ISSUE IS THE
POTENTIAL PRESSURE FALLS IF THIS SYSTEM STRENGTHENS EVEN
MORE...IT COULD ADD ANOTHER FOOT ONTO THE SURGE.

FRIDAY...LOW CONFIDENCE.

ONCE UPPER LOW AND SURFACE SYSTEM MOVES INTO SOUTHERN CANADA...
EXPECT A RATHER FAST UPPER W FLOW IN PLACE. MAY SEE SOME LEFTOVER
SNOW SHOWERS ACROSS THE E SLOPES OF THE BERKSHIRES. GUSTY W-SW
WINDS CONTINUE AS TEMPS FALL BACK TO MORE SEASONABLE LEVELS.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...

FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /THROUGH SUNDAY/...

105 AM UPDATE...

TODAY...MODERATE CONFIDENCE.  MVFR CIGS WILL CONTINUE TO OVERSPREAD
EASTERN NEW ENGLAND THIS MORNING AND EVENTUALLY INTO THE INTERIOR
THIS AFTERNOON.  SCATTERED PRECIPITATION WILL OVERSPREAD
SOUTHEAST MA/CAPE/ISLANDS THIS AFTERNOON.  PTYPE MAINLY SNOW SHOWERS
NORTHWEST OF THE SOUTHEAST PLYMOUTH COUNTY COAST AND RAIN SHOWERS
SOUTHEAST OF THAT REGION. LOCALIZED IFR CONDITIONS POSSIBLE JUST
INLAND FROM THE SOUTHEAST NEW ENGLAND COAST...WHERE PTYPE IS SNOW.

TONIGHT AND SUNDAY...MODERATE CONFIDENCE.  MVFR CONDITIONS DOMINATE
IN LOWER CLOUDS AND SCATTERED PRECIPITATION.  LOCALIZED IFR
CONDITIONS POSSIBLE WITH THE BEST CHANCE IN SNOW SHOWERS.
PRECIPITATION AFFECTS MAINLY EASTERN NEW ENGLAND BUT STILL SOME
SCATTERED ACTIVITY ACROSS WESTERN NEW ENGLAND. PTYPE MAINLY SNOW
SHOWERS NORTHWEST OF THE SOUTHEAST PLYMOUTH COUNTY COAST AND RAIN
SHOWERS SOUTHEAST OF THAT REGION.

KBOS TERMINAL...MODERATE CONFIDENCE IN TAF.  SNOW SHOWERS MAY ARRIVE
TOWARDS 00Z THIS EVENING.

KBDL TERMINAL...MODERATE CONFIDENCE IN TAF.

OUTLOOK...SUNDAY NIGHT THROUGH WEDNESDAY...

MONDAY...MODERATE CONFIDENCE. MAINLY VFR.

MONDAY NIGHT-TUESDAY...MODERATE CONFIDENCE. DEVELOPING RAIN OR
MIXED PRECIP FROM S-N MON NIGHT WITH MVFR CONDITIONS. MAY SEE
-FZRA/-PL ACROSS CENTRAL AND WESTERN AREAS AROUND OR AFTER
MIDNIGHT INTO TUE MORNING THEN SHOULD CHANGE TO RAIN AS TEMPS
RISE. E-SE WINDS GUSTING TO 20-25 KT ALONG S COAST TUE.

TUESDAY NIGHT-WEDNESDAY...MODERATE CONFIDENCE. MVFR-IFR
CONDITIONS IN RAIN...HEAVY AT TIMES DURING WED. ISOLD THUNDER
POSSIBLE WED AFTERNOON/EVENING. E WINDS SHIFTING TO SE-S LATE TUE
NIGHT/WED WITH GUSTS UP TO 25-30 KT...HIGHEST ACROSS CAPE COD AND
THE ISLANDS.

&&

.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.

HIGH PRESSURE BUILDING EAST TO MAINE AND THE MARITIMES WILL KEEP
WINDS/SEAS BELOW SCA THRESHOLDS THROUGH SATURDAY NIGHT...WITH WIND
SPEEDS LESS THAN 20 KT. NORTHERLY WINDS TONIGHT BECOMING NE
SAT/SAT NIGHT. GUSTS UP TO 20 KT POSSIBLE SAT NIGHT ACROSS NE MA
COASTAL WATERS.

OUTLOOK...SUNDAY THROUGH WEDNESDAY...MODERATE TO HIGH CONFIDENCE.

SUNDAY THROUGH MONDAY NIGHT...WINDS AND SEAS BELOW SMALL CRAFT
CRITERIA. E WINDS GUSTING UP TO 20 KT MON NIGHT.

TUESDAY-WEDNESDAY...E WINDS INCREASE...GUSTING TO 30 KT TUE THEN
SHIFT TO SE GUSTING TO 30-35 KT WED...HIGHEST ON THE OUTER
WATERS. SEAS BUILD UP TO 7-11 FT BY WED. GALES ON THE OUTER WATERS
LIKELY.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...KJC/EVT
NEAR TERM...FRANK
SHORT TERM...KJC
LONG TERM...EVT
AVIATION...FRANK/EVT
MARINE...KJC/EVT




000
FXUS61 KBOX 200247
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
947 PM EST FRI DEC 19 2014

.SYNOPSIS...

A WEAK DISTURBANCE AND ONSHORE FLOW WILL RESULT IN A PERIOD OF
LIGHT SNOW/RAIN SHOWERS MAINLY ACROSS EASTERN NEW ENGLAND THIS
WEEKEND INTO EARLY NEXT WEEK. LOW PRESSURE WILL PASS SOUTH OF NEW
ENGLAND...BRINGING ANOTHER PERIOD OF PRECIPITATION. A MUCH
STRONGER STORM PASSING WEST OF NEW ENGLAND WILL BRING HEAVY
RAINFALL...GUSTY WINDS AND COASTAL FLOODING CONCERNS TO THE
REGION WEDNESDAY INTO WEDNESDAY EVENING. DRY BUT VERY WINDY
CONDITIONS FOLLOW FOR CHRISTMAS DAY INTO FRIDAY.

&&

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

945 PM UPDATE...

SKIES HAVE TEMPORARILY BECOME MOSTLY CLEAR TO PARTLY CLOUDY
ACROSS MUCH OF THE REGION...AS DRIER AIR HAS WORKED IN FROM THE
NORTHEAST.  THE EXCEPTION WAS DOWN ALONG THE SOUTH
COAST/CAPE/ISLANDS AND PORTIONS OF THE CT RIVER
VALLEY...WHERE SKIES WERE STILL MOSTLY CLOUDY.

AN APPROACHING SHORTWAVE WILL BEGIN TO TURN 925 MB WINDS TO A LIGHT
EASTERLY DIRECTION OVERNIGHT.  THIS WILL ALLOW FOR LOW CLOUDS TO
BACK IN OFF THE OCEAN ACROSS EASTERN NEW ENGLAND BY DAYBREAK...WHILE
THE INTERIOR REMAINS PARTLY CLOUDY.

LOW TEMPS BY DAYBREAK WILL MAINLY BE IN THE 20S.  THE EXCEPTION WILL
BE THE OUTER-CAPE/ACK WHERE TEMPS WILL BE HELD IN THE LOWER TO
MIDDLE 30S GIVEN CLOUDS AND ONSHORE FLOW.  A FEW FLURRIES OR VERY
LIGHT SNOW SHOWERS MAY DEVELOP NEAR 12Z SATURDAY ACROSS
CAPE/ISLANDS...BUT BULK OF ACTIVITY WILL HOLD OFF UNTIL LATER SAT
AND SAT NIGHT.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
HIGH PRES BUILDS ACROSS N MAINE AND THE MARITIMES WITH LOW LEVEL
FLOW VEERING TO THE E WHILE SFC WINDS MOSTLY NE. THIS WILL RESULT
IN LOW CLOUDS EXPANDING WEST ACROSS SNE DURING SAT AS LOW LEVEL
MOISTURE INCREASES. NOT REALLY LOOKING AT A PURE OCEAN EFFECT
SITUATION AS INSTABILITY IS MARGINAL. HOWEVER...HI-RES GUIDANCE
PICKING UP ON A DEVELOPING COASTAL FRONT ACROSS CAPE COD VICINITY
WITH E WINDS TO THE E OF THE BOUNDARY AND N/NE WINDS TO THE WEST.
LOW LEVEL FORCING COMBINED WITH DEEPENING MOISTURE AS MID LEVEL
SHORTWAVE MOVES IN FROM THE WEST WILL RESULT IN RAIN/SNOW SHOWERS
EXPANDING WEST FROM CAPE COD INTO EASTERN HALF NEW ENG. WHILE SOME
LIGHT PRECIP IS POSSIBLE IN THE MORNING...ESPECIALLY CAPE
COD...BULK OF PRECIP OCCURS LATER SAT INTO SAT NIGHT ASSOCD WITH
DEEPER MOISTURE AND LOW LEVEL LIFT FROM THE COASTAL FRONT/INVERTED
TROF.

PTYPE/SNOW ACCUM...
LOOKING AT MOSTLY RAIN FOR CAPE/ISLANDS AND POSSIBLY INTO SE
COASTAL PLYMOUTH COUNTY WHERE E WINDS WILL SUFFICIENTLY WARM THE
BOUNDARY LAYER KEEPING TEMPS IN THE MID/UPPER 30S. HOWEVER...JUST
INLAND AND NORTH FROM THE IMMEDIATE SE COAST AND WEST OF THE
COASTAL FRONT WHERE WINDS ARE FORECAST TO BE MORE
NORTHERLY...EXPECT MOSTLY SNOW ALTHOUGH THERE COULD BE A MIX AT
THE START. FREEZING DRIZZLE IS NOT LIKELY AS THE COLUMN MOISTENS
LATE SAT INTO SAT NIGHT WITH TEMPS -10C IN THE MOIST LAYER WHICH
IS COLD ENOUGH FOR ICE CRYSTAL PRODUCTION.

NAM IS PICKING UP ON SOME ENHANCEMENT IN N PLYMOUTH COUNTY INTO
NORFOLK COUNTY WITH QPF UP TO A THIRD OF AN INCH. THIS LIKELY
ASSOCD WITH A 20-25 KT E/NE LOW LEVEL JET THAT THE NAM IS
FORECASTING. HOWEVER...THIS MIGHT BE OVERDONE AS HI-RES WRF QPF
IS LESS AND OTHER MODELS ARE WEAKER WITH THE LOW LEVEL NE FLOW.
DONT WANT TO COMPLETELY IGNORE THE NAM AS IT SOMETIMES CAN PICK
UP ON HEAVIER MESOSCALE PRECIP IN THESE SITUATIONS SO USED A
BLEND OF NAM/GFS QPF TO TEMPER NAM OUTPUT. MAINLY LOOKING AT A
COATING TO AN INCH FOR EASTERN NEW ENG...HIGHEST AMOUNTS ACROSS E
MA AWAY FROM THE IMMEDIATE COAST. LOCALIZED AMOUNTS UP TO 2 INCHES
POSSIBLE...ESPECIALLY JUST SW OF BOSTON.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
HIGHLIGHTS...

* SCT SNOW/RAIN SHOWERS LINGER ON SUNDAY WITH SLIGHTLY BELOW
  NORMAL TEMPS
* WEAK LOW PRES WILL PASS SOUTH OF NEW ENGLAND MONDAY NIGHT AND
  TUESDAY BRINGING LIGHT PRECIPITATION...AS WELL AS A WINTRY MIX
  TO THE INTERIOR
* STRENGTHENING LOW PRES WILL WRAP UP AROUND ANOMALOUS VORTEX
  ACROSS THE GREAT LAKES...BRINGING HEAVY RAIN...GUSTY WINDS AND
  COASTAL CONCERNS TO THE REGION LATE WEDNESDAY INTO CHRISTMAS EVE

OVERVIEW AND MODEL PREFERENCES...

MEDIUM RANGE MODEL SUITE CONTINUES TO SIGNAL DEVELOPMENT OF
AMPLIFIED UPPER LEVEL PATTERN ACROSS NORTH AMERICA THROUGH THIS
FORECAST PERIOD. AN H5 CUTOFF VORTEX WILL DOMINATE ACROSS THE GREAT
LAKES AND ITS EXTENDING LONG WAVE TROUGH WRAPPING AROUND TO THE
EASTERN SEABOARD AS IT BECOMES NEGATIVELY TILTED. WITH OVERALL SW
FLOW IN PLACE...WILL SEE WEAK SYSTEMS WORK TOWARD THE REGION EARLY
IN THE PERIOD. A STRONGER LOW WILL DEVELOP NEAR OR JUST OFF THE SE
U.S. COAST AROUND EARLY WED AND PASS W OF THE REGION WED NIGHT...
BRINGING GUSTY WINDS...HEAVY RAINFALL WITH A FEW THUNDERSTORMS
POSSIBLE AS WELL AS POSSIBLE COASTAL CONCERNS.

WHILE THERE ARE STILL SOME TIMING AND TRACK VARIANCES WITH THE MID
WEEK SYSTEM...MODELS AND ENSEMBLES REMAIN IN GOOD AGREEMENT WITH THE
DEVELOPMENT OF THIS AMPLIFIED PATTERN...AS WELL AS THE UPPER
LEVEL VORTEX ACROSS THE GREAT LAKES AND SURFACE SYSTEM THAT WILL
MORE THAN LIKELY AFFECT THE REGION DURING THE WEDNESDAY-WEDNESDAY
NIGHT TIMEFRAME.

USED A BLEND OF AVAILABLE GUIDANCE AS WELL AS GFS/EC ENSEMBLE MEANS
FOR THIS FORECAST WHICH SHOWED GOOD CONTINUITY TO THE PREVIOUS
FORECAST.

DETAILS...

SUNDAY AND MONDAY...MODERATE TO HIGH CONFIDENCE.

LEFTOVER MOISTURE WILL LINGER SUNDAY MORNING WITH LIGHT RAIN
AND/OR SNOW SHOWERS MAINLY ACROSS E MA/RI THOUGH COULD SEE SOME
ISOLD ACTIVITY FURTHER INLAND AS COASTAL FRONT WEAKENS. RIDGING
WILL NOSE DOWN THE COAST FROM HIGH PRES OVER NORTHERN NEW ENGLAND
AND QUEBEC SUN NIGHT INTO MONDAY...BRINGING A BRIEF DRY PERIOD
THOUGH CLOUDS WILL LINGER WITH A CONTINUED ONSHORE WIND
FLOW...ALBEIT WEAK. EXPECT TEMPS TO RUN NEAR OR SLIGHTLY BELOW
NORMAL...THOUGH WILL BE A BIT MILDER ALONG THE S COAST DURING MON.

BY LATE MONDAY...MAY START TO SEE SOME PRECIP WORK INTO THE LOWER
CT VALLEY AS A WEAK LOW MOVES OFF THE MID ATLC COAST.

MONDAY NIGHT-TUESDAY...MODERATE CONFIDENCE.

WEAK COASTAL LOW WILL PASS OFF THE SOUTH COAST...BUT WILL BRING
ENOUGH MOISTURE AND LIFT FOR PRECIP TO MOVE IN FROM S-N. TEMPS
WILL STILL BE CHILLY THOUGH...ESPECIALLY INLAND THERE THE COLDER
AIR WILL BE TRAPPED... SO WILL SEE SOME MIXED PRECIP /SLEET AND/OR
FREEZING RAIN/. EVEN THOUGH QPF WILL BE LIGHT...COULD BE ENOUGH TO
CAUSE SOME LIGHT GLAZING PROBLEMS LATE MON NIGHT INTO TUE MORNING.
STILL SOME TIMING ISSUES AS WELL AS QUESTIONS WITH THERMAL
PROFILES...BUT MAY NEED WINTER WX HEADLINES DURING THIS TIMEFRAME.
SOMETHING TO MONITOR CLOSELY.

BY TUE AFTERNOON...TEMPS SHOULD RECOVER WITH GRADUALLY INCREASING
E-SE WINDS...SO WILL SEE ALL RAIN BY THEN. HIGHS ON TUE WILL
RANGE FROM THE UPPER 30S ACROSS THE HIGHER INLAND TERRAIN TO THE
MID AND UPPER 40S ALONG THE COAST.

ONE OTHER ISSUE THAT MAY NEED ATTENTION WILL BE THE LONG EASTERLY
FETCH AND INCREASING ASTRONOMICAL TIDES ON TUESDAY. BOSTON
HARBOR/S HIGH TIDE OCCURS AT 1142 AM AT 11.6 FEET. SURFACE WINDS
LOOK TO REMAIN AT 15 KT OR LESS BUT...WITH THE MAINLY EASTERLY
WIND DIRECTION OVER SEVERAL DAYS...MAY SEE SOME GROUND SWELLS WORK
IN WHICH COULD CAUSE SOME POSSIBLE SPLASHOVER DURING THE MIDDAY
TIDE.

WEDNESDAY AND THURSDAY...HIGH CONFIDENCE IN SYSTEM DEVELOPMENT AND
EFFECTS...LOW TO MODERATE CONFIDENCE ON TIMING DETAILS.

WILL SEE STRONG SURFACE SYSTEM AND ITS ASSOCIATED H5 CUTOFF
VORTEX WILL BE INTENSIFYING DURING THIS TIMEFRAME...WHILE LONG
WAVE TROUGHING WILL BECOME NEGATIVELY TILTED AROUND THE MID ATLC
OR SE U.S. COAST. A SECONDARY LOW...WITH ENERGY AND TROPICAL
MOISTURE WORKING IN FROM THE GULF OF MEXICO...WILL INTENSIFY
DURING WED AS IT WRAPS AROUND THE LARGER UPPER LEVEL CIRCULATION.
LOOKS LIKE THIS LOW WILL PASS W OF THE REGION...BUT WILL BE IN THE
AREA OF BEST MOISTURE CONVERGENCE AND TRANSPORT UP THE EASTERN
SEABOARD. THE 12Z GFS IS BULLISH IN BRINGING SLUG OF HEAVY QPF
ACROSS THE REGION. BOTH THE 12Z EC AND GGEM ALSO SIGNAL THIS
INFLUX THOUGH NOT QUITE AS HIGH ON THE PRECIP AMTS.

STILL NOTING PWATS AT 1.4 TO 1.5 INCHES...RUNNING 2-3SD ABOVE
SEASONAL NORMALS AT ABOUT THE TIME OF THE HEAVIEST PRECIP LATE
WED INTO WED EVENING. ON TOP OF THIS...SOME GOOD INSTABILITY MOVES
ACROSS WITH K INDICES IN THE LOWER-MID 30S AND TOTAL TOTALS IN THE
LOWER 50S. WOULD NOT BE SURPRISED TO SEE SOME ISOLD THUNDER SO
MENTIONED IN THE FORECAST MAINLY DURING WED NIGHT...ALONG WITH
HEAVY RAINFALL FROM THE CONVECTION. LOW LEVEL JET ON ORDER OF
40-55 KT AT H85 AND 50-60 KT AT H925...SO COULD ALSO SEE GUSTY
WINDS ESPECIALLY WITH ANY STORMS. OH...ONE MORE THING...THERE
WILL BE A BRIEF BURST OF MILDER AIR THAT WORKS IN WITH THIS
SYSTEM. EXPECT TEMPS TO RISE TO THE MID 40S WELL INLAND TO THE
MID 50S AT THE COAST...BUT WILL NOT TOP OFF UNTIL CLOSE TO
MIDNIGHT WED NIGHT...WHICH WILL HELP SUPPORT THE INSTABILITY.

MODELS CONTINUE TO SIGNAL FAST MOVEMENT OF THE SURFACE SYSTEM
LATE WED NIGHT...WITH DRY SLOT WORKING ACROSS THE REGION AFTER
MIDNIGHT WITH DRY CONDITIONS BY DAWN ON CHRISTMAS MORNING. WINDS
WILL QUICKLY SHIFT AROUND TO W-SW AND WILL BECOME VERY GUSTY WITH
THE LOW LEVEL JET IN PLACE AND COLDER AIR WRAPPING IN.

MAY HAVE SOME COASTAL FLOODING ISSUES WITH HIGHEST ASTRONOMICAL
TIDES OF THE MONTH OCCUR ON WED AND THU...UP TO 11.7 FT AND 11.5
FT RESPECTIVELY FOR BOSTON. ANY EASTERLY COMPONENT WILL PUSH THE
TIDE ABOVE FLOOD...SO COASTAL FLOODING IS POSSIBLE AS WELL AS
BEACH EROSION ON THE WED TIDE ALONG E FACING BEACHES. THE SOUTH
COASTLINE WILL ALSO HAVE TO BE WATCH CLOSELY ON THU AS WINDS SHIFT
TO W- SW...THOUGH E COASTAL AREAS COULD SEE PROBLEMS WITH
CONTINUED E SWELLS. AS MENTIONED ABOVE...STRONG SOUTHERLY JET
DEVELOPS WED INTO THU AND...WITH ASTRONOMICAL HIGH TIDES...COULD
ALSO SEE MINOR TO MODERATE COASTAL FLOODING. ANOTHER ISSUE IS THE
POTENTIAL PRESSURE FALLS IF THIS SYSTEM STRENGTHENS EVEN
MORE...IT COULD ADD ANOTHER FOOT ONTO THE SURGE.

FRIDAY...LOW CONFIDENCE.

ONCE UPPER LOW AND SURFACE SYSTEM MOVES INTO SOUTHERN CANADA...
EXPECT A RATHER FAST UPPER W FLOW IN PLACE. MAY SEE SOME LEFTOVER
SNOW SHOWERS ACROSS THE E SLOPES OF THE BERKSHIRES. GUSTY W-SW
WINDS CONTINUE AS TEMPS FALL BACK TO MORE SEASONABLE LEVELS.

&&

.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /THROUGH SATURDAY NIGHT/...

TONIGHT...MODERATE CONFIDENCE. CLEARING SKIES AND VFR CONDITIONS
WILL PUSH INTO CENTRAL AND WESTERN AREAS THROUGH MIDNIGHT AS LOW
LEVEL DRY AIR MOVES ACROSS THE REGION. HOWEVER...LOW CLOUDS AND
MVFR CIGS OVER THE OUTER CAPE WILL GRADUALLY BACK IN ACROSS E
COASTAL MA OVERNIGHT.

SATURDAY...MODERATE CONFIDENCE. MVFR CIGS ACROSS SE NEW ENG WILL
EXPAND WEST ACROSS THE REST OF THE COASTAL PLAIN THEN INTO THE
INTERIOR DURING THE AFTERNOON. CT VALLEY SHOULD REMAIN VFR.
SCATTERED RAIN SHOWERS WILL DEVELOP OVER CAPE COD WITH SNOW
SHOWERS INTO E MA BY LATE AFTERNOON.

SATURDAY NIGHT...MODERATE CONFIDENCE. WIDESPREAD MVFR CIGS WITH
POCKETS OF IFR E MA COAST. PERIODS OF LIGHT RAIN OVER CAPE COD
WITH LIGHT SNOW FURTHER INLAND ACROSS E MA. MINOR ACCUM POSSIBLE
ACROSS E MA JUST INLAND FROM THE IMMEDIATE COAST.

KBOS TERMINAL...MODERATE CONFIDENCE IN TAF. VFR TONIGHT...THEN
MVFR CIGS DEVELOP SAT MORNING.

KBDL TERMINAL...MODERATE CONFIDENCE IN TAF.

OUTLOOK...SUNDAY THROUGH WEDNESDAY...

SUNDAY...HIGH CONFIDENCE. MAINLY VFR ACROSS CENTRAL AND WESTERN
AREAS. E MA/RI...MAY SEE LOCAL MVFR CONDITIONS IN RAIN/SNOW
SHOWERS INTO THE AFTERNOON...THEN SLOW IMPROVEMENT FROM W-E.

MONDAY...MODERATE CONFIDENCE. MAINLY VFR.

MONDAY NIGHT-TUESDAY...MODERATE CONFIDENCE. DEVELOPING RAIN OR
MIXED PRECIP FROM S-N MON NIGHT WITH MVFR CONDITIONS. MAY SEE
-FZRA/-PL ACROSS CENTRAL AND WESTERN AREAS AROUND OR AFTER
MIDNIGHT INTO TUE MORNING THEN SHOULD CHANGE TO RAIN AS TEMPS
RISE. E-SE WINDS GUSTING TO 20-25 KT ALONG S COAST TUE.

TUESDAY NIGHT-WEDNESDAY...MODERATE CONFIDENCE. MVFR-IFR
CONDITIONS IN RAIN...HEAVY AT TIMES DURING WED. ISOLD THUNDER
POSSIBLE WED AFTERNOON/EVENING. E WINDS SHIFTING TO SE-S LATE TUE
NIGHT/WED WITH GUSTS UP TO 25-30 KT...HIGHEST ACROSS CAPE COD AND
THE ISLANDS.

&&

.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.

HIGH PRESSURE BUILDING EAST TO MAINE AND THE MARITIMES WILL KEEP
WINDS/SEAS BELOW SCA THRESHOLDS THROUGH SATURDAY NIGHT...WITH WIND
SPEEDS LESS THAN 20 KT. NORTHERLY WINDS TONIGHT BECOMING NE
SAT/SAT NIGHT. GUSTS UP TO 20 KT POSSIBLE SAT NIGHT ACROSS NE MA
COASTAL WATERS.

OUTLOOK...SUNDAY THROUGH WEDNESDAY...MODERATE TO HIGH CONFIDENCE.

SUNDAY THROUGH MONDAY NIGHT...WINDS AND SEAS BELOW SMALL CRAFT
CRITERIA. E WINDS GUSTING UP TO 20 KT MON NIGHT.

TUESDAY-WEDNESDAY...E WINDS INCREASE...GUSTING TO 30 KT TUE THEN
SHIFT TO SE GUSTING TO 30-35 KT WED...HIGHEST ON THE OUTER
WATERS. SEAS BUILD UP TO 7-11 FT BY WED. GALES ON THE OUTER WATERS
LIKELY.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...KJC/EVT
NEAR TERM...FRANK
SHORT TERM...KJC
LONG TERM...EVT
AVIATION...KJC/EVT
MARINE...KJC/EVT




000
FXUS61 KBOX 200247
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
947 PM EST FRI DEC 19 2014

.SYNOPSIS...

A WEAK DISTURBANCE AND ONSHORE FLOW WILL RESULT IN A PERIOD OF
LIGHT SNOW/RAIN SHOWERS MAINLY ACROSS EASTERN NEW ENGLAND THIS
WEEKEND INTO EARLY NEXT WEEK. LOW PRESSURE WILL PASS SOUTH OF NEW
ENGLAND...BRINGING ANOTHER PERIOD OF PRECIPITATION. A MUCH
STRONGER STORM PASSING WEST OF NEW ENGLAND WILL BRING HEAVY
RAINFALL...GUSTY WINDS AND COASTAL FLOODING CONCERNS TO THE
REGION WEDNESDAY INTO WEDNESDAY EVENING. DRY BUT VERY WINDY
CONDITIONS FOLLOW FOR CHRISTMAS DAY INTO FRIDAY.

&&

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

945 PM UPDATE...

SKIES HAVE TEMPORARILY BECOME MOSTLY CLEAR TO PARTLY CLOUDY
ACROSS MUCH OF THE REGION...AS DRIER AIR HAS WORKED IN FROM THE
NORTHEAST.  THE EXCEPTION WAS DOWN ALONG THE SOUTH
COAST/CAPE/ISLANDS AND PORTIONS OF THE CT RIVER
VALLEY...WHERE SKIES WERE STILL MOSTLY CLOUDY.

AN APPROACHING SHORTWAVE WILL BEGIN TO TURN 925 MB WINDS TO A LIGHT
EASTERLY DIRECTION OVERNIGHT.  THIS WILL ALLOW FOR LOW CLOUDS TO
BACK IN OFF THE OCEAN ACROSS EASTERN NEW ENGLAND BY DAYBREAK...WHILE
THE INTERIOR REMAINS PARTLY CLOUDY.

LOW TEMPS BY DAYBREAK WILL MAINLY BE IN THE 20S.  THE EXCEPTION WILL
BE THE OUTER-CAPE/ACK WHERE TEMPS WILL BE HELD IN THE LOWER TO
MIDDLE 30S GIVEN CLOUDS AND ONSHORE FLOW.  A FEW FLURRIES OR VERY
LIGHT SNOW SHOWERS MAY DEVELOP NEAR 12Z SATURDAY ACROSS
CAPE/ISLANDS...BUT BULK OF ACTIVITY WILL HOLD OFF UNTIL LATER SAT
AND SAT NIGHT.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
HIGH PRES BUILDS ACROSS N MAINE AND THE MARITIMES WITH LOW LEVEL
FLOW VEERING TO THE E WHILE SFC WINDS MOSTLY NE. THIS WILL RESULT
IN LOW CLOUDS EXPANDING WEST ACROSS SNE DURING SAT AS LOW LEVEL
MOISTURE INCREASES. NOT REALLY LOOKING AT A PURE OCEAN EFFECT
SITUATION AS INSTABILITY IS MARGINAL. HOWEVER...HI-RES GUIDANCE
PICKING UP ON A DEVELOPING COASTAL FRONT ACROSS CAPE COD VICINITY
WITH E WINDS TO THE E OF THE BOUNDARY AND N/NE WINDS TO THE WEST.
LOW LEVEL FORCING COMBINED WITH DEEPENING MOISTURE AS MID LEVEL
SHORTWAVE MOVES IN FROM THE WEST WILL RESULT IN RAIN/SNOW SHOWERS
EXPANDING WEST FROM CAPE COD INTO EASTERN HALF NEW ENG. WHILE SOME
LIGHT PRECIP IS POSSIBLE IN THE MORNING...ESPECIALLY CAPE
COD...BULK OF PRECIP OCCURS LATER SAT INTO SAT NIGHT ASSOCD WITH
DEEPER MOISTURE AND LOW LEVEL LIFT FROM THE COASTAL FRONT/INVERTED
TROF.

PTYPE/SNOW ACCUM...
LOOKING AT MOSTLY RAIN FOR CAPE/ISLANDS AND POSSIBLY INTO SE
COASTAL PLYMOUTH COUNTY WHERE E WINDS WILL SUFFICIENTLY WARM THE
BOUNDARY LAYER KEEPING TEMPS IN THE MID/UPPER 30S. HOWEVER...JUST
INLAND AND NORTH FROM THE IMMEDIATE SE COAST AND WEST OF THE
COASTAL FRONT WHERE WINDS ARE FORECAST TO BE MORE
NORTHERLY...EXPECT MOSTLY SNOW ALTHOUGH THERE COULD BE A MIX AT
THE START. FREEZING DRIZZLE IS NOT LIKELY AS THE COLUMN MOISTENS
LATE SAT INTO SAT NIGHT WITH TEMPS -10C IN THE MOIST LAYER WHICH
IS COLD ENOUGH FOR ICE CRYSTAL PRODUCTION.

NAM IS PICKING UP ON SOME ENHANCEMENT IN N PLYMOUTH COUNTY INTO
NORFOLK COUNTY WITH QPF UP TO A THIRD OF AN INCH. THIS LIKELY
ASSOCD WITH A 20-25 KT E/NE LOW LEVEL JET THAT THE NAM IS
FORECASTING. HOWEVER...THIS MIGHT BE OVERDONE AS HI-RES WRF QPF
IS LESS AND OTHER MODELS ARE WEAKER WITH THE LOW LEVEL NE FLOW.
DONT WANT TO COMPLETELY IGNORE THE NAM AS IT SOMETIMES CAN PICK
UP ON HEAVIER MESOSCALE PRECIP IN THESE SITUATIONS SO USED A
BLEND OF NAM/GFS QPF TO TEMPER NAM OUTPUT. MAINLY LOOKING AT A
COATING TO AN INCH FOR EASTERN NEW ENG...HIGHEST AMOUNTS ACROSS E
MA AWAY FROM THE IMMEDIATE COAST. LOCALIZED AMOUNTS UP TO 2 INCHES
POSSIBLE...ESPECIALLY JUST SW OF BOSTON.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
HIGHLIGHTS...

* SCT SNOW/RAIN SHOWERS LINGER ON SUNDAY WITH SLIGHTLY BELOW
  NORMAL TEMPS
* WEAK LOW PRES WILL PASS SOUTH OF NEW ENGLAND MONDAY NIGHT AND
  TUESDAY BRINGING LIGHT PRECIPITATION...AS WELL AS A WINTRY MIX
  TO THE INTERIOR
* STRENGTHENING LOW PRES WILL WRAP UP AROUND ANOMALOUS VORTEX
  ACROSS THE GREAT LAKES...BRINGING HEAVY RAIN...GUSTY WINDS AND
  COASTAL CONCERNS TO THE REGION LATE WEDNESDAY INTO CHRISTMAS EVE

OVERVIEW AND MODEL PREFERENCES...

MEDIUM RANGE MODEL SUITE CONTINUES TO SIGNAL DEVELOPMENT OF
AMPLIFIED UPPER LEVEL PATTERN ACROSS NORTH AMERICA THROUGH THIS
FORECAST PERIOD. AN H5 CUTOFF VORTEX WILL DOMINATE ACROSS THE GREAT
LAKES AND ITS EXTENDING LONG WAVE TROUGH WRAPPING AROUND TO THE
EASTERN SEABOARD AS IT BECOMES NEGATIVELY TILTED. WITH OVERALL SW
FLOW IN PLACE...WILL SEE WEAK SYSTEMS WORK TOWARD THE REGION EARLY
IN THE PERIOD. A STRONGER LOW WILL DEVELOP NEAR OR JUST OFF THE SE
U.S. COAST AROUND EARLY WED AND PASS W OF THE REGION WED NIGHT...
BRINGING GUSTY WINDS...HEAVY RAINFALL WITH A FEW THUNDERSTORMS
POSSIBLE AS WELL AS POSSIBLE COASTAL CONCERNS.

WHILE THERE ARE STILL SOME TIMING AND TRACK VARIANCES WITH THE MID
WEEK SYSTEM...MODELS AND ENSEMBLES REMAIN IN GOOD AGREEMENT WITH THE
DEVELOPMENT OF THIS AMPLIFIED PATTERN...AS WELL AS THE UPPER
LEVEL VORTEX ACROSS THE GREAT LAKES AND SURFACE SYSTEM THAT WILL
MORE THAN LIKELY AFFECT THE REGION DURING THE WEDNESDAY-WEDNESDAY
NIGHT TIMEFRAME.

USED A BLEND OF AVAILABLE GUIDANCE AS WELL AS GFS/EC ENSEMBLE MEANS
FOR THIS FORECAST WHICH SHOWED GOOD CONTINUITY TO THE PREVIOUS
FORECAST.

DETAILS...

SUNDAY AND MONDAY...MODERATE TO HIGH CONFIDENCE.

LEFTOVER MOISTURE WILL LINGER SUNDAY MORNING WITH LIGHT RAIN
AND/OR SNOW SHOWERS MAINLY ACROSS E MA/RI THOUGH COULD SEE SOME
ISOLD ACTIVITY FURTHER INLAND AS COASTAL FRONT WEAKENS. RIDGING
WILL NOSE DOWN THE COAST FROM HIGH PRES OVER NORTHERN NEW ENGLAND
AND QUEBEC SUN NIGHT INTO MONDAY...BRINGING A BRIEF DRY PERIOD
THOUGH CLOUDS WILL LINGER WITH A CONTINUED ONSHORE WIND
FLOW...ALBEIT WEAK. EXPECT TEMPS TO RUN NEAR OR SLIGHTLY BELOW
NORMAL...THOUGH WILL BE A BIT MILDER ALONG THE S COAST DURING MON.

BY LATE MONDAY...MAY START TO SEE SOME PRECIP WORK INTO THE LOWER
CT VALLEY AS A WEAK LOW MOVES OFF THE MID ATLC COAST.

MONDAY NIGHT-TUESDAY...MODERATE CONFIDENCE.

WEAK COASTAL LOW WILL PASS OFF THE SOUTH COAST...BUT WILL BRING
ENOUGH MOISTURE AND LIFT FOR PRECIP TO MOVE IN FROM S-N. TEMPS
WILL STILL BE CHILLY THOUGH...ESPECIALLY INLAND THERE THE COLDER
AIR WILL BE TRAPPED... SO WILL SEE SOME MIXED PRECIP /SLEET AND/OR
FREEZING RAIN/. EVEN THOUGH QPF WILL BE LIGHT...COULD BE ENOUGH TO
CAUSE SOME LIGHT GLAZING PROBLEMS LATE MON NIGHT INTO TUE MORNING.
STILL SOME TIMING ISSUES AS WELL AS QUESTIONS WITH THERMAL
PROFILES...BUT MAY NEED WINTER WX HEADLINES DURING THIS TIMEFRAME.
SOMETHING TO MONITOR CLOSELY.

BY TUE AFTERNOON...TEMPS SHOULD RECOVER WITH GRADUALLY INCREASING
E-SE WINDS...SO WILL SEE ALL RAIN BY THEN. HIGHS ON TUE WILL
RANGE FROM THE UPPER 30S ACROSS THE HIGHER INLAND TERRAIN TO THE
MID AND UPPER 40S ALONG THE COAST.

ONE OTHER ISSUE THAT MAY NEED ATTENTION WILL BE THE LONG EASTERLY
FETCH AND INCREASING ASTRONOMICAL TIDES ON TUESDAY. BOSTON
HARBOR/S HIGH TIDE OCCURS AT 1142 AM AT 11.6 FEET. SURFACE WINDS
LOOK TO REMAIN AT 15 KT OR LESS BUT...WITH THE MAINLY EASTERLY
WIND DIRECTION OVER SEVERAL DAYS...MAY SEE SOME GROUND SWELLS WORK
IN WHICH COULD CAUSE SOME POSSIBLE SPLASHOVER DURING THE MIDDAY
TIDE.

WEDNESDAY AND THURSDAY...HIGH CONFIDENCE IN SYSTEM DEVELOPMENT AND
EFFECTS...LOW TO MODERATE CONFIDENCE ON TIMING DETAILS.

WILL SEE STRONG SURFACE SYSTEM AND ITS ASSOCIATED H5 CUTOFF
VORTEX WILL BE INTENSIFYING DURING THIS TIMEFRAME...WHILE LONG
WAVE TROUGHING WILL BECOME NEGATIVELY TILTED AROUND THE MID ATLC
OR SE U.S. COAST. A SECONDARY LOW...WITH ENERGY AND TROPICAL
MOISTURE WORKING IN FROM THE GULF OF MEXICO...WILL INTENSIFY
DURING WED AS IT WRAPS AROUND THE LARGER UPPER LEVEL CIRCULATION.
LOOKS LIKE THIS LOW WILL PASS W OF THE REGION...BUT WILL BE IN THE
AREA OF BEST MOISTURE CONVERGENCE AND TRANSPORT UP THE EASTERN
SEABOARD. THE 12Z GFS IS BULLISH IN BRINGING SLUG OF HEAVY QPF
ACROSS THE REGION. BOTH THE 12Z EC AND GGEM ALSO SIGNAL THIS
INFLUX THOUGH NOT QUITE AS HIGH ON THE PRECIP AMTS.

STILL NOTING PWATS AT 1.4 TO 1.5 INCHES...RUNNING 2-3SD ABOVE
SEASONAL NORMALS AT ABOUT THE TIME OF THE HEAVIEST PRECIP LATE
WED INTO WED EVENING. ON TOP OF THIS...SOME GOOD INSTABILITY MOVES
ACROSS WITH K INDICES IN THE LOWER-MID 30S AND TOTAL TOTALS IN THE
LOWER 50S. WOULD NOT BE SURPRISED TO SEE SOME ISOLD THUNDER SO
MENTIONED IN THE FORECAST MAINLY DURING WED NIGHT...ALONG WITH
HEAVY RAINFALL FROM THE CONVECTION. LOW LEVEL JET ON ORDER OF
40-55 KT AT H85 AND 50-60 KT AT H925...SO COULD ALSO SEE GUSTY
WINDS ESPECIALLY WITH ANY STORMS. OH...ONE MORE THING...THERE
WILL BE A BRIEF BURST OF MILDER AIR THAT WORKS IN WITH THIS
SYSTEM. EXPECT TEMPS TO RISE TO THE MID 40S WELL INLAND TO THE
MID 50S AT THE COAST...BUT WILL NOT TOP OFF UNTIL CLOSE TO
MIDNIGHT WED NIGHT...WHICH WILL HELP SUPPORT THE INSTABILITY.

MODELS CONTINUE TO SIGNAL FAST MOVEMENT OF THE SURFACE SYSTEM
LATE WED NIGHT...WITH DRY SLOT WORKING ACROSS THE REGION AFTER
MIDNIGHT WITH DRY CONDITIONS BY DAWN ON CHRISTMAS MORNING. WINDS
WILL QUICKLY SHIFT AROUND TO W-SW AND WILL BECOME VERY GUSTY WITH
THE LOW LEVEL JET IN PLACE AND COLDER AIR WRAPPING IN.

MAY HAVE SOME COASTAL FLOODING ISSUES WITH HIGHEST ASTRONOMICAL
TIDES OF THE MONTH OCCUR ON WED AND THU...UP TO 11.7 FT AND 11.5
FT RESPECTIVELY FOR BOSTON. ANY EASTERLY COMPONENT WILL PUSH THE
TIDE ABOVE FLOOD...SO COASTAL FLOODING IS POSSIBLE AS WELL AS
BEACH EROSION ON THE WED TIDE ALONG E FACING BEACHES. THE SOUTH
COASTLINE WILL ALSO HAVE TO BE WATCH CLOSELY ON THU AS WINDS SHIFT
TO W- SW...THOUGH E COASTAL AREAS COULD SEE PROBLEMS WITH
CONTINUED E SWELLS. AS MENTIONED ABOVE...STRONG SOUTHERLY JET
DEVELOPS WED INTO THU AND...WITH ASTRONOMICAL HIGH TIDES...COULD
ALSO SEE MINOR TO MODERATE COASTAL FLOODING. ANOTHER ISSUE IS THE
POTENTIAL PRESSURE FALLS IF THIS SYSTEM STRENGTHENS EVEN
MORE...IT COULD ADD ANOTHER FOOT ONTO THE SURGE.

FRIDAY...LOW CONFIDENCE.

ONCE UPPER LOW AND SURFACE SYSTEM MOVES INTO SOUTHERN CANADA...
EXPECT A RATHER FAST UPPER W FLOW IN PLACE. MAY SEE SOME LEFTOVER
SNOW SHOWERS ACROSS THE E SLOPES OF THE BERKSHIRES. GUSTY W-SW
WINDS CONTINUE AS TEMPS FALL BACK TO MORE SEASONABLE LEVELS.

&&

.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /THROUGH SATURDAY NIGHT/...

TONIGHT...MODERATE CONFIDENCE. CLEARING SKIES AND VFR CONDITIONS
WILL PUSH INTO CENTRAL AND WESTERN AREAS THROUGH MIDNIGHT AS LOW
LEVEL DRY AIR MOVES ACROSS THE REGION. HOWEVER...LOW CLOUDS AND
MVFR CIGS OVER THE OUTER CAPE WILL GRADUALLY BACK IN ACROSS E
COASTAL MA OVERNIGHT.

SATURDAY...MODERATE CONFIDENCE. MVFR CIGS ACROSS SE NEW ENG WILL
EXPAND WEST ACROSS THE REST OF THE COASTAL PLAIN THEN INTO THE
INTERIOR DURING THE AFTERNOON. CT VALLEY SHOULD REMAIN VFR.
SCATTERED RAIN SHOWERS WILL DEVELOP OVER CAPE COD WITH SNOW
SHOWERS INTO E MA BY LATE AFTERNOON.

SATURDAY NIGHT...MODERATE CONFIDENCE. WIDESPREAD MVFR CIGS WITH
POCKETS OF IFR E MA COAST. PERIODS OF LIGHT RAIN OVER CAPE COD
WITH LIGHT SNOW FURTHER INLAND ACROSS E MA. MINOR ACCUM POSSIBLE
ACROSS E MA JUST INLAND FROM THE IMMEDIATE COAST.

KBOS TERMINAL...MODERATE CONFIDENCE IN TAF. VFR TONIGHT...THEN
MVFR CIGS DEVELOP SAT MORNING.

KBDL TERMINAL...MODERATE CONFIDENCE IN TAF.

OUTLOOK...SUNDAY THROUGH WEDNESDAY...

SUNDAY...HIGH CONFIDENCE. MAINLY VFR ACROSS CENTRAL AND WESTERN
AREAS. E MA/RI...MAY SEE LOCAL MVFR CONDITIONS IN RAIN/SNOW
SHOWERS INTO THE AFTERNOON...THEN SLOW IMPROVEMENT FROM W-E.

MONDAY...MODERATE CONFIDENCE. MAINLY VFR.

MONDAY NIGHT-TUESDAY...MODERATE CONFIDENCE. DEVELOPING RAIN OR
MIXED PRECIP FROM S-N MON NIGHT WITH MVFR CONDITIONS. MAY SEE
-FZRA/-PL ACROSS CENTRAL AND WESTERN AREAS AROUND OR AFTER
MIDNIGHT INTO TUE MORNING THEN SHOULD CHANGE TO RAIN AS TEMPS
RISE. E-SE WINDS GUSTING TO 20-25 KT ALONG S COAST TUE.

TUESDAY NIGHT-WEDNESDAY...MODERATE CONFIDENCE. MVFR-IFR
CONDITIONS IN RAIN...HEAVY AT TIMES DURING WED. ISOLD THUNDER
POSSIBLE WED AFTERNOON/EVENING. E WINDS SHIFTING TO SE-S LATE TUE
NIGHT/WED WITH GUSTS UP TO 25-30 KT...HIGHEST ACROSS CAPE COD AND
THE ISLANDS.

&&

.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.

HIGH PRESSURE BUILDING EAST TO MAINE AND THE MARITIMES WILL KEEP
WINDS/SEAS BELOW SCA THRESHOLDS THROUGH SATURDAY NIGHT...WITH WIND
SPEEDS LESS THAN 20 KT. NORTHERLY WINDS TONIGHT BECOMING NE
SAT/SAT NIGHT. GUSTS UP TO 20 KT POSSIBLE SAT NIGHT ACROSS NE MA
COASTAL WATERS.

OUTLOOK...SUNDAY THROUGH WEDNESDAY...MODERATE TO HIGH CONFIDENCE.

SUNDAY THROUGH MONDAY NIGHT...WINDS AND SEAS BELOW SMALL CRAFT
CRITERIA. E WINDS GUSTING UP TO 20 KT MON NIGHT.

TUESDAY-WEDNESDAY...E WINDS INCREASE...GUSTING TO 30 KT TUE THEN
SHIFT TO SE GUSTING TO 30-35 KT WED...HIGHEST ON THE OUTER
WATERS. SEAS BUILD UP TO 7-11 FT BY WED. GALES ON THE OUTER WATERS
LIKELY.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...KJC/EVT
NEAR TERM...FRANK
SHORT TERM...KJC
LONG TERM...EVT
AVIATION...KJC/EVT
MARINE...KJC/EVT





000
FXUS61 KBOX 200017
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
717 PM EST FRI DEC 19 2014

.SYNOPSIS...
A WEAK DISTURBANCE AND ONSHORE FLOW WILL RESULT IN A PERIOD OF
LIGHT SNOW/RAIN SHOWERS MAINLY ACROSS EASTERN NEW ENGLAND THIS
WEEKEND INTO EARLY NEXT WEEK. LOW PRESSURE WILL PASS SOUTH OF NEW
ENGLAND...BRINGING ANOTHER PERIOD OF PRECIPITATION. A MUCH
STRONGER STORM PASSING WEST OF NEW ENGLAND WILL BRING HEAVY
RAINFALL...GUSTY WINDS AND COASTAL FLOODING CONCERNS TO THE
REGION WEDNESDAY INTO WEDNESDAY EVENING. DRY BUT VERY WINDY
CONDITIONS FOLLOW FOR CHRISTMAS DAY INTO FRIDAY.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
705 PM UPDATE...
DRIER AIR CONTINUES TO WORK DOWN THE E COAST OUT OF W ME/NH AT
00Z...BRINGING CLEARING SKIES TO MOST OF E MA. ALSO NOTING BREAKS
IN THE CLOUDS FURTHER S AND W AS SEEN ON LATEST IR SATELLITE
IMAGERY. THIS IS MATCHING UP WELL WITH THE PREVIOUS FORECAST.
UPDATED CLOUD COVER TO BRING CONDITIONS CURRENT.

TEMPS RUNNING A LITTLE BIT WARMER THAN PREVIOUS FORECAST AT 00Z SO
UPDATED TO BRING CURRENT. HOWEVER...FEEL TEMPS WILL FALL TO
FORECASTED LEVELS OVERNIGHT WITH DIMINISHING WINDS AND CLEARING
SKIES ACROSS THE REMAINDER OF THE REGION. HOWEVER...CLOUDS WILL
BEGIN TO APPROACH THE E COAST OFF THE OCEAN AFTER MIDNIGHT AS
LIGHT WINDS SHIFT TO N-NE.

PREVIOUS DISCUSSION...
NAM IS HANDLING LOW LEVEL DRY AIR AND CLEARING SKIES FAIRLY WELL.
HOWEVER...LOW LEVEL MOISTURE WILL REMAIN LOCKED IN ACROSS CAPE COD
AND BACK IN ACROSS SE MA OVERNIGHT. IT LOOKS MOSTLY DRY THROUGH
THE NIGHT. MIN TEMPS MOSTLY IN THE 20S...WITH LOWER 30S OUTER
CAPE/ACK. TEMPS COULD DROP INTO THE TEENS N AND W MA IF THERE IS
SUFFICIENT CLEARING.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
HIGH PRES BUILDS ACROSS N MAINE AND THE MARITIMES WITH LOW LEVEL
FLOW VEERING TO THE E WHILE SFC WINDS MOSTLY NE. THIS WILL RESULT
IN LOW CLOUDS EXPANDING WEST ACROSS SNE DURING SAT AS LOW LEVEL
MOISTURE INCREASES. NOT REALLY LOOKING AT A PURE OCEAN EFFECT
SITUATION AS INSTABILITY IS MARGINAL. HOWEVER...HI-RES GUIDANCE
PICKING UP ON A DEVELOPING COASTAL FRONT ACROSS CAPE COD VICINITY
WITH E WINDS TO THE E OF THE BOUNDARY AND N/NE WINDS TO THE WEST.
LOW LEVEL FORCING COMBINED WITH DEEPENING MOISTURE AS MID LEVEL
SHORTWAVE MOVES IN FROM THE WEST WILL RESULT IN RAIN/SNOW SHOWERS
EXPANDING WEST FROM CAPE COD INTO EASTERN HALF NEW ENG. WHILE SOME
LIGHT PRECIP IS POSSIBLE IN THE MORNING...ESPECIALLY CAPE
COD...BULK OF PRECIP OCCURS LATER SAT INTO SAT NIGHT ASSOCD WITH
DEEPER MOISTURE AND LOW LEVEL LIFT FROM THE COASTAL FRONT/INVERTED
TROF.

PTYPE/SNOW ACCUM...
LOOKING AT MOSTLY RAIN FOR CAPE/ISLANDS AND POSSIBLY INTO SE
COASTAL PLYMOUTH COUNTY WHERE E WINDS WILL SUFFICIENTLY WARM THE
BOUNDARY LAYER KEEPING TEMPS IN THE MID/UPPER 30S. HOWEVER...JUST
INLAND AND NORTH FROM THE IMMEDIATE SE COAST AND WEST OF THE
COASTAL FRONT WHERE WINDS ARE FORECAST TO BE MORE
NORTHERLY...EXPECT MOSTLY SNOW ALTHOUGH THERE COULD BE A MIX AT
THE START. FREEZING DRIZZLE IS NOT LIKELY AS THE COLUMN MOISTENS
LATE SAT INTO SAT NIGHT WITH TEMPS -10C IN THE MOIST LAYER WHICH
IS COLD ENOUGH FOR ICE CRYSTAL PRODUCTION.

NAM IS PICKING UP ON SOME ENHANCEMENT IN N PLYMOUTH COUNTY INTO
NORFOLK COUNTY WITH QPF UP TO A THIRD OF AN INCH. THIS LIKELY
ASSOCD WITH A 20-25 KT E/NE LOW LEVEL JET THAT THE NAM IS
FORECASTING. HOWEVER...THIS MIGHT BE OVERDONE AS HI-RES WRF QPF
IS LESS AND OTHER MODELS ARE WEAKER WITH THE LOW LEVEL NE FLOW.
DONT WANT TO COMPLETELY IGNORE THE NAM AS IT SOMETIMES CAN PICK
UP ON HEAVIER MESOSCALE PRECIP IN THESE SITUATIONS SO USED A
BLEND OF NAM/GFS QPF TO TEMPER NAM OUTPUT. MAINLY LOOKING AT A
COATING TO AN INCH FOR EASTERN NEW ENG...HIGHEST AMOUNTS ACROSS E
MA AWAY FROM THE IMMEDIATE COAST. LOCALIZED AMOUNTS UP TO 2 INCHES
POSSIBLE...ESPECIALLY JUST SW OF BOSTON.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
HIGHLIGHTS...

* SCT SNOW/RAIN SHOWERS LINGER ON SUNDAY WITH SLIGHTLY BELOW
  NORMAL TEMPS
* WEAK LOW PRES WILL PASS SOUTH OF NEW ENGLAND MONDAY NIGHT AND
  TUESDAY BRINGING LIGHT PRECIPITATION...AS WELL AS A WINTRY MIX
  TO THE INTERIOR
* STRENGTHENING LOW PRES WILL WRAP UP AROUND ANOMALOUS VORTEX
  ACROSS THE GREAT LAKES...BRINGING HEAVY RAIN...GUSTY WINDS AND
  COASTAL CONCERNS TO THE REGION LATE WEDNESDAY INTO CHRISTMAS EVE

OVERVIEW AND MODEL PREFERENCES...

MEDIUM RANGE MODEL SUITE CONTINUES TO SIGNAL DEVELOPMENT OF
AMPLIFIED UPPER LEVEL PATTERN ACROSS NORTH AMERICA THROUGH THIS
FORECAST PERIOD. AN H5 CUTOFF VORTEX WILL DOMINATE ACROSS THE GREAT
LAKES AND ITS EXTENDING LONG WAVE TROUGH WRAPPING AROUND TO THE
EASTERN SEABOARD AS IT BECOMES NEGATIVELY TILTED. WITH OVERALL SW
FLOW IN PLACE...WILL SEE WEAK SYSTEMS WORK TOWARD THE REGION EARLY
IN THE PERIOD. A STRONGER LOW WILL DEVELOP NEAR OR JUST OFF THE SE
U.S. COAST AROUND EARLY WED AND PASS W OF THE REGION WED NIGHT...
BRINGING GUSTY WINDS...HEAVY RAINFALL WITH A FEW THUNDERSTORMS
POSSIBLE AS WELL AS POSSIBLE COASTAL CONCERNS.

WHILE THERE ARE STILL SOME TIMING AND TRACK VARIANCES WITH THE MID
WEEK SYSTEM...MODELS AND ENSEMBLES REMAIN IN GOOD AGREEMENT WITH THE
DEVELOPMENT OF THIS AMPLIFIED PATTERN...AS WELL AS THE UPPER
LEVEL VORTEX ACROSS THE GREAT LAKES AND SURFACE SYSTEM THAT WILL
MORE THAN LIKELY AFFECT THE REGION DURING THE WEDNESDAY-WEDNESDAY
NIGHT TIMEFRAME.

USED A BLEND OF AVAILABLE GUIDANCE AS WELL AS GFS/EC ENSEMBLE MEANS
FOR THIS FORECAST WHICH SHOWED GOOD CONTINUITY TO THE PREVIOUS
FORECAST.

DETAILS...

SUNDAY AND MONDAY...MODERATE TO HIGH CONFIDENCE.

LEFTOVER MOISTURE WILL LINGER SUNDAY MORNING WITH LIGHT RAIN
AND/OR SNOW SHOWERS MAINLY ACROSS E MA/RI THOUGH COULD SEE SOME
ISOLD ACTIVITY FURTHER INLAND AS COASTAL FRONT WEAKENS. RIDGING
WILL NOSE DOWN THE COAST FROM HIGH PRES OVER NORTHERN NEW ENGLAND
AND QUEBEC SUN NIGHT INTO MONDAY...BRINGING A BRIEF DRY PERIOD
THOUGH CLOUDS WILL LINGER WITH A CONTINUED ONSHORE WIND
FLOW...ALBEIT WEAK. EXPECT TEMPS TO RUN NEAR OR SLIGHTLY BELOW
NORMAL...THOUGH WILL BE A BIT MILDER ALONG THE S COAST DURING MON.

BY LATE MONDAY...MAY START TO SEE SOME PRECIP WORK INTO THE LOWER
CT VALLEY AS A WEAK LOW MOVES OFF THE MID ATLC COAST.

MONDAY NIGHT-TUESDAY...MODERATE CONFIDENCE.

WEAK COASTAL LOW WILL PASS OFF THE SOUTH COAST...BUT WILL BRING
ENOUGH MOISTURE AND LIFT FOR PRECIP TO MOVE IN FROM S-N. TEMPS
WILL STILL BE CHILLY THOUGH...ESPECIALLY INLAND THERE THE COLDER
AIR WILL BE TRAPPED... SO WILL SEE SOME MIXED PRECIP /SLEET AND/OR
FREEZING RAIN/. EVEN THOUGH QPF WILL BE LIGHT...COULD BE ENOUGH TO
CAUSE SOME LIGHT GLAZING PROBLEMS LATE MON NIGHT INTO TUE MORNING.
STILL SOME TIMING ISSUES AS WELL AS QUESTIONS WITH THERMAL
PROFILES...BUT MAY NEED WINTER WX HEADLINES DURING THIS TIMEFRAME.
SOMETHING TO MONITOR CLOSELY.

BY TUE AFTERNOON...TEMPS SHOULD RECOVER WITH GRADUALLY INCREASING
E-SE WINDS...SO WILL SEE ALL RAIN BY THEN. HIGHS ON TUE WILL
RANGE FROM THE UPPER 30S ACROSS THE HIGHER INLAND TERRAIN TO THE
MID AND UPPER 40S ALONG THE COAST.

ONE OTHER ISSUE THAT MAY NEED ATTENTION WILL BE THE LONG EASTERLY
FETCH AND INCREASING ASTRONOMICAL TIDES ON TUESDAY. BOSTON
HARBOR/S HIGH TIDE OCCURS AT 1142 AM AT 11.6 FEET. SURFACE WINDS
LOOK TO REMAIN AT 15 KT OR LESS BUT...WITH THE MAINLY EASTERLY
WIND DIRECTION OVER SEVERAL DAYS...MAY SEE SOME GROUND SWELLS WORK
IN WHICH COULD CAUSE SOME POSSIBLE SPLASHOVER DURING THE MIDDAY
TIDE.

WEDNESDAY AND THURSDAY...HIGH CONFIDENCE IN SYSTEM DEVELOPMENT AND
EFFECTS...LOW TO MODERATE CONFIDENCE ON TIMING DETAILS.

WILL SEE STRONG SURFACE SYSTEM AND ITS ASSOCIATED H5 CUTOFF
VORTEX WILL BE INTENSIFYING DURING THIS TIMEFRAME...WHILE LONG
WAVE TROUGHING WILL BECOME NEGATIVELY TILTED AROUND THE MID ATLC
OR SE U.S. COAST. A SECONDARY LOW...WITH ENERGY AND TROPICAL
MOISTURE WORKING IN FROM THE GULF OF MEXICO...WILL INTENSIFY
DURING WED AS IT WRAPS AROUND THE LARGER UPPER LEVEL CIRCULATION.
LOOKS LIKE THIS LOW WILL PASS W OF THE REGION...BUT WILL BE IN THE
AREA OF BEST MOISTURE CONVERGENCE AND TRANSPORT UP THE EASTERN
SEABOARD. THE 12Z GFS IS BULLISH IN BRINGING SLUG OF HEAVY QPF
ACROSS THE REGION. BOTH THE 12Z EC AND GGEM ALSO SIGNAL THIS
INFLUX THOUGH NOT QUITE AS HIGH ON THE PRECIP AMTS.

STILL NOTING PWATS AT 1.4 TO 1.5 INCHES...RUNNING 2-3SD ABOVE
SEASONAL NORMALS AT ABOUT THE TIME OF THE HEAVIEST PRECIP LATE
WED INTO WED EVENING. ON TOP OF THIS...SOME GOOD INSTABILITY MOVES
ACROSS WITH K INDICES IN THE LOWER-MID 30S AND TOTAL TOTALS IN THE
LOWER 50S. WOULD NOT BE SURPRISED TO SEE SOME ISOLD THUNDER SO
MENTIONED IN THE FORECAST MAINLY DURING WED NIGHT...ALONG WITH
HEAVY RAINFALL FROM THE CONVECTION. LOW LEVEL JET ON ORDER OF
40-55 KT AT H85 AND 50-60 KT AT H925...SO COULD ALSO SEE GUSTY
WINDS ESPECIALLY WITH ANY STORMS. OH...ONE MORE THING...THERE
WILL BE A BRIEF BURST OF MILDER AIR THAT WORKS IN WITH THIS
SYSTEM. EXPECT TEMPS TO RISE TO THE MID 40S WELL INLAND TO THE
MID 50S AT THE COAST...BUT WILL NOT TOP OFF UNTIL CLOSE TO
MIDNIGHT WED NIGHT...WHICH WILL HELP SUPPORT THE INSTABILITY.

MODELS CONTINUE TO SIGNAL FAST MOVEMENT OF THE SURFACE SYSTEM
LATE WED NIGHT...WITH DRY SLOT WORKING ACROSS THE REGION AFTER
MIDNIGHT WITH DRY CONDITIONS BY DAWN ON CHRISTMAS MORNING. WINDS
WILL QUICKLY SHIFT AROUND TO W-SW AND WILL BECOME VERY GUSTY WITH
THE LOW LEVEL JET IN PLACE AND COLDER AIR WRAPPING IN.

MAY HAVE SOME COASTAL FLOODING ISSUES WITH HIGHEST ASTRONOMICAL
TIDES OF THE MONTH OCCUR ON WED AND THU...UP TO 11.7 FT AND 11.5
FT RESPECTIVELY FOR BOSTON. ANY EASTERLY COMPONENT WILL PUSH THE
TIDE ABOVE FLOOD...SO COASTAL FLOODING IS POSSIBLE AS WELL AS
BEACH EROSION ON THE WED TIDE ALONG E FACING BEACHES. THE SOUTH
COASTLINE WILL ALSO HAVE TO BE WATCH CLOSELY ON THU AS WINDS SHIFT
TO W- SW...THOUGH E COASTAL AREAS COULD SEE PROBLEMS WITH
CONTINUED E SWELLS. AS MENTIONED ABOVE...STRONG SOUTHERLY JET
DEVELOPS WED INTO THU AND...WITH ASTRONOMICAL HIGH TIDES...COULD
ALSO SEE MINOR TO MODERATE COASTAL FLOODING. ANOTHER ISSUE IS THE
POTENTIAL PRESSURE FALLS IF THIS SYSTEM STRENGTHENS EVEN
MORE...IT COULD ADD ANOTHER FOOT ONTO THE SURGE.

FRIDAY...LOW CONFIDENCE.

ONCE UPPER LOW AND SURFACE SYSTEM MOVES INTO SOUTHERN CANADA...
EXPECT A RATHER FAST UPPER W FLOW IN PLACE. MAY SEE SOME LEFTOVER
SNOW SHOWERS ACROSS THE E SLOPES OF THE BERKSHIRES. GUSTY W-SW
WINDS CONTINUE AS TEMPS FALL BACK TO MORE SEASONABLE LEVELS.

&&

.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /THROUGH SATURDAY NIGHT/...

TONIGHT...MODERATE CONFIDENCE. CLEARING SKIES AND VFR CONDITIONS
WILL PUSH INTO CENTRAL AND WESTERN AREAS THROUGH MIDNIGHT AS LOW
LEVEL DRY AIR MOVES ACROSS THE REGION. HOWEVER...LOW CLOUDS AND
MVFR CIGS OVER THE OUTER CAPE WILL GRADUALLY BACK IN ACROSS E
COASTAL MA OVERNIGHT.

SATURDAY...MODERATE CONFIDENCE. MVFR CIGS ACROSS SE NEW ENG WILL
EXPAND WEST ACROSS THE REST OF THE COASTAL PLAIN THEN INTO THE
INTERIOR DURING THE AFTERNOON. CT VALLEY SHOULD REMAIN VFR.
SCATTERED RAIN SHOWERS WILL DEVELOP OVER CAPE COD WITH SNOW
SHOWERS INTO E MA BY LATE AFTERNOON.

SATURDAY NIGHT...MODERATE CONFIDENCE. WIDESPREAD MVFR CIGS WITH
POCKETS OF IFR E MA COAST. PERIODS OF LIGHT RAIN OVER CAPE COD
WITH LIGHT SNOW FURTHER INLAND ACROSS E MA. MINOR ACCUM POSSIBLE
ACROSS E MA JUST INLAND FROM THE IMMEDIATE COAST.

KBOS TERMINAL...MODERATE CONFIDENCE IN TAF. VFR TONIGHT...THEN
MVFR CIGS DEVELOP SAT MORNING.

KBDL TERMINAL...MODERATE CONFIDENCE IN TAF.

OUTLOOK...SUNDAY THROUGH WEDNESDAY...

SUNDAY...HIGH CONFIDENCE. MAINLY VFR ACROSS CENTRAL AND WESTERN
AREAS. E MA/RI...MAY SEE LOCAL MVFR CONDITIONS IN RAIN/SNOW
SHOWERS INTO THE AFTERNOON...THEN SLOW IMPROVEMENT FROM W-E.

MONDAY...MODERATE CONFIDENCE. MAINLY VFR.

MONDAY NIGHT-TUESDAY...MODERATE CONFIDENCE. DEVELOPING RAIN OR
MIXED PRECIP FROM S-N MON NIGHT WITH MVFR CONDITIONS. MAY SEE
-FZRA/-PL ACROSS CENTRAL AND WESTERN AREAS AROUND OR AFTER
MIDNIGHT INTO TUE MORNING THEN SHOULD CHANGE TO RAIN AS TEMPS
RISE. E-SE WINDS GUSTING TO 20-25 KT ALONG S COAST TUE.

TUESDAY NIGHT-WEDNESDAY...MODERATE CONFIDENCE. MVFR-IFR
CONDITIONS IN RAIN...HEAVY AT TIMES DURING WED. ISOLD THUNDER
POSSIBLE WED AFTERNOON/EVENING. E WINDS SHIFTING TO SE-S LATE TUE
NIGHT/WED WITH GUSTS UP TO 25-30 KT...HIGHEST ACROSS CAPE COD AND
THE ISLANDS.

&&

.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.

HIGH PRESSURE BUILDING EAST TO MAINE AND THE MARITIMES WILL KEEP
WINDS/SEAS BELOW SCA THRESHOLDS THROUGH SATURDAY NIGHT...WITH WIND
SPEEDS LESS THAN 20 KT. NORTHERLY WINDS TONIGHT BECOMING NE
SAT/SAT NIGHT. GUSTS UP TO 20 KT POSSIBLE SAT NIGHT ACROSS NE MA
COASTAL WATERS.

OUTLOOK...SUNDAY THROUGH WEDNESDAY...MODERATE TO HIGH CONFIDENCE.

SUNDAY THROUGH MONDAY NIGHT...WINDS AND SEAS BELOW SMALL CRAFT
CRITERIA. E WINDS GUSTING UP TO 20 KT MON NIGHT.

TUESDAY-WEDNESDAY...E WINDS INCREASE...GUSTING TO 30 KT TUE THEN
SHIFT TO SE GUSTING TO 30-35 KT WED...HIGHEST ON THE OUTER
WATERS. SEAS BUILD UP TO 7-11 FT BY WED. GALES ON THE OUTER WATERS
LIKELY.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...KJC/EVT
NEAR TERM...KJC/EVT
SHORT TERM...KJC
LONG TERM...EVT
AVIATION...KJC/EVT
MARINE...KJC/EVT




000
FXUS61 KBOX 200017
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
717 PM EST FRI DEC 19 2014

.SYNOPSIS...
A WEAK DISTURBANCE AND ONSHORE FLOW WILL RESULT IN A PERIOD OF
LIGHT SNOW/RAIN SHOWERS MAINLY ACROSS EASTERN NEW ENGLAND THIS
WEEKEND INTO EARLY NEXT WEEK. LOW PRESSURE WILL PASS SOUTH OF NEW
ENGLAND...BRINGING ANOTHER PERIOD OF PRECIPITATION. A MUCH
STRONGER STORM PASSING WEST OF NEW ENGLAND WILL BRING HEAVY
RAINFALL...GUSTY WINDS AND COASTAL FLOODING CONCERNS TO THE
REGION WEDNESDAY INTO WEDNESDAY EVENING. DRY BUT VERY WINDY
CONDITIONS FOLLOW FOR CHRISTMAS DAY INTO FRIDAY.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
705 PM UPDATE...
DRIER AIR CONTINUES TO WORK DOWN THE E COAST OUT OF W ME/NH AT
00Z...BRINGING CLEARING SKIES TO MOST OF E MA. ALSO NOTING BREAKS
IN THE CLOUDS FURTHER S AND W AS SEEN ON LATEST IR SATELLITE
IMAGERY. THIS IS MATCHING UP WELL WITH THE PREVIOUS FORECAST.
UPDATED CLOUD COVER TO BRING CONDITIONS CURRENT.

TEMPS RUNNING A LITTLE BIT WARMER THAN PREVIOUS FORECAST AT 00Z SO
UPDATED TO BRING CURRENT. HOWEVER...FEEL TEMPS WILL FALL TO
FORECASTED LEVELS OVERNIGHT WITH DIMINISHING WINDS AND CLEARING
SKIES ACROSS THE REMAINDER OF THE REGION. HOWEVER...CLOUDS WILL
BEGIN TO APPROACH THE E COAST OFF THE OCEAN AFTER MIDNIGHT AS
LIGHT WINDS SHIFT TO N-NE.

PREVIOUS DISCUSSION...
NAM IS HANDLING LOW LEVEL DRY AIR AND CLEARING SKIES FAIRLY WELL.
HOWEVER...LOW LEVEL MOISTURE WILL REMAIN LOCKED IN ACROSS CAPE COD
AND BACK IN ACROSS SE MA OVERNIGHT. IT LOOKS MOSTLY DRY THROUGH
THE NIGHT. MIN TEMPS MOSTLY IN THE 20S...WITH LOWER 30S OUTER
CAPE/ACK. TEMPS COULD DROP INTO THE TEENS N AND W MA IF THERE IS
SUFFICIENT CLEARING.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
HIGH PRES BUILDS ACROSS N MAINE AND THE MARITIMES WITH LOW LEVEL
FLOW VEERING TO THE E WHILE SFC WINDS MOSTLY NE. THIS WILL RESULT
IN LOW CLOUDS EXPANDING WEST ACROSS SNE DURING SAT AS LOW LEVEL
MOISTURE INCREASES. NOT REALLY LOOKING AT A PURE OCEAN EFFECT
SITUATION AS INSTABILITY IS MARGINAL. HOWEVER...HI-RES GUIDANCE
PICKING UP ON A DEVELOPING COASTAL FRONT ACROSS CAPE COD VICINITY
WITH E WINDS TO THE E OF THE BOUNDARY AND N/NE WINDS TO THE WEST.
LOW LEVEL FORCING COMBINED WITH DEEPENING MOISTURE AS MID LEVEL
SHORTWAVE MOVES IN FROM THE WEST WILL RESULT IN RAIN/SNOW SHOWERS
EXPANDING WEST FROM CAPE COD INTO EASTERN HALF NEW ENG. WHILE SOME
LIGHT PRECIP IS POSSIBLE IN THE MORNING...ESPECIALLY CAPE
COD...BULK OF PRECIP OCCURS LATER SAT INTO SAT NIGHT ASSOCD WITH
DEEPER MOISTURE AND LOW LEVEL LIFT FROM THE COASTAL FRONT/INVERTED
TROF.

PTYPE/SNOW ACCUM...
LOOKING AT MOSTLY RAIN FOR CAPE/ISLANDS AND POSSIBLY INTO SE
COASTAL PLYMOUTH COUNTY WHERE E WINDS WILL SUFFICIENTLY WARM THE
BOUNDARY LAYER KEEPING TEMPS IN THE MID/UPPER 30S. HOWEVER...JUST
INLAND AND NORTH FROM THE IMMEDIATE SE COAST AND WEST OF THE
COASTAL FRONT WHERE WINDS ARE FORECAST TO BE MORE
NORTHERLY...EXPECT MOSTLY SNOW ALTHOUGH THERE COULD BE A MIX AT
THE START. FREEZING DRIZZLE IS NOT LIKELY AS THE COLUMN MOISTENS
LATE SAT INTO SAT NIGHT WITH TEMPS -10C IN THE MOIST LAYER WHICH
IS COLD ENOUGH FOR ICE CRYSTAL PRODUCTION.

NAM IS PICKING UP ON SOME ENHANCEMENT IN N PLYMOUTH COUNTY INTO
NORFOLK COUNTY WITH QPF UP TO A THIRD OF AN INCH. THIS LIKELY
ASSOCD WITH A 20-25 KT E/NE LOW LEVEL JET THAT THE NAM IS
FORECASTING. HOWEVER...THIS MIGHT BE OVERDONE AS HI-RES WRF QPF
IS LESS AND OTHER MODELS ARE WEAKER WITH THE LOW LEVEL NE FLOW.
DONT WANT TO COMPLETELY IGNORE THE NAM AS IT SOMETIMES CAN PICK
UP ON HEAVIER MESOSCALE PRECIP IN THESE SITUATIONS SO USED A
BLEND OF NAM/GFS QPF TO TEMPER NAM OUTPUT. MAINLY LOOKING AT A
COATING TO AN INCH FOR EASTERN NEW ENG...HIGHEST AMOUNTS ACROSS E
MA AWAY FROM THE IMMEDIATE COAST. LOCALIZED AMOUNTS UP TO 2 INCHES
POSSIBLE...ESPECIALLY JUST SW OF BOSTON.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
HIGHLIGHTS...

* SCT SNOW/RAIN SHOWERS LINGER ON SUNDAY WITH SLIGHTLY BELOW
  NORMAL TEMPS
* WEAK LOW PRES WILL PASS SOUTH OF NEW ENGLAND MONDAY NIGHT AND
  TUESDAY BRINGING LIGHT PRECIPITATION...AS WELL AS A WINTRY MIX
  TO THE INTERIOR
* STRENGTHENING LOW PRES WILL WRAP UP AROUND ANOMALOUS VORTEX
  ACROSS THE GREAT LAKES...BRINGING HEAVY RAIN...GUSTY WINDS AND
  COASTAL CONCERNS TO THE REGION LATE WEDNESDAY INTO CHRISTMAS EVE

OVERVIEW AND MODEL PREFERENCES...

MEDIUM RANGE MODEL SUITE CONTINUES TO SIGNAL DEVELOPMENT OF
AMPLIFIED UPPER LEVEL PATTERN ACROSS NORTH AMERICA THROUGH THIS
FORECAST PERIOD. AN H5 CUTOFF VORTEX WILL DOMINATE ACROSS THE GREAT
LAKES AND ITS EXTENDING LONG WAVE TROUGH WRAPPING AROUND TO THE
EASTERN SEABOARD AS IT BECOMES NEGATIVELY TILTED. WITH OVERALL SW
FLOW IN PLACE...WILL SEE WEAK SYSTEMS WORK TOWARD THE REGION EARLY
IN THE PERIOD. A STRONGER LOW WILL DEVELOP NEAR OR JUST OFF THE SE
U.S. COAST AROUND EARLY WED AND PASS W OF THE REGION WED NIGHT...
BRINGING GUSTY WINDS...HEAVY RAINFALL WITH A FEW THUNDERSTORMS
POSSIBLE AS WELL AS POSSIBLE COASTAL CONCERNS.

WHILE THERE ARE STILL SOME TIMING AND TRACK VARIANCES WITH THE MID
WEEK SYSTEM...MODELS AND ENSEMBLES REMAIN IN GOOD AGREEMENT WITH THE
DEVELOPMENT OF THIS AMPLIFIED PATTERN...AS WELL AS THE UPPER
LEVEL VORTEX ACROSS THE GREAT LAKES AND SURFACE SYSTEM THAT WILL
MORE THAN LIKELY AFFECT THE REGION DURING THE WEDNESDAY-WEDNESDAY
NIGHT TIMEFRAME.

USED A BLEND OF AVAILABLE GUIDANCE AS WELL AS GFS/EC ENSEMBLE MEANS
FOR THIS FORECAST WHICH SHOWED GOOD CONTINUITY TO THE PREVIOUS
FORECAST.

DETAILS...

SUNDAY AND MONDAY...MODERATE TO HIGH CONFIDENCE.

LEFTOVER MOISTURE WILL LINGER SUNDAY MORNING WITH LIGHT RAIN
AND/OR SNOW SHOWERS MAINLY ACROSS E MA/RI THOUGH COULD SEE SOME
ISOLD ACTIVITY FURTHER INLAND AS COASTAL FRONT WEAKENS. RIDGING
WILL NOSE DOWN THE COAST FROM HIGH PRES OVER NORTHERN NEW ENGLAND
AND QUEBEC SUN NIGHT INTO MONDAY...BRINGING A BRIEF DRY PERIOD
THOUGH CLOUDS WILL LINGER WITH A CONTINUED ONSHORE WIND
FLOW...ALBEIT WEAK. EXPECT TEMPS TO RUN NEAR OR SLIGHTLY BELOW
NORMAL...THOUGH WILL BE A BIT MILDER ALONG THE S COAST DURING MON.

BY LATE MONDAY...MAY START TO SEE SOME PRECIP WORK INTO THE LOWER
CT VALLEY AS A WEAK LOW MOVES OFF THE MID ATLC COAST.

MONDAY NIGHT-TUESDAY...MODERATE CONFIDENCE.

WEAK COASTAL LOW WILL PASS OFF THE SOUTH COAST...BUT WILL BRING
ENOUGH MOISTURE AND LIFT FOR PRECIP TO MOVE IN FROM S-N. TEMPS
WILL STILL BE CHILLY THOUGH...ESPECIALLY INLAND THERE THE COLDER
AIR WILL BE TRAPPED... SO WILL SEE SOME MIXED PRECIP /SLEET AND/OR
FREEZING RAIN/. EVEN THOUGH QPF WILL BE LIGHT...COULD BE ENOUGH TO
CAUSE SOME LIGHT GLAZING PROBLEMS LATE MON NIGHT INTO TUE MORNING.
STILL SOME TIMING ISSUES AS WELL AS QUESTIONS WITH THERMAL
PROFILES...BUT MAY NEED WINTER WX HEADLINES DURING THIS TIMEFRAME.
SOMETHING TO MONITOR CLOSELY.

BY TUE AFTERNOON...TEMPS SHOULD RECOVER WITH GRADUALLY INCREASING
E-SE WINDS...SO WILL SEE ALL RAIN BY THEN. HIGHS ON TUE WILL
RANGE FROM THE UPPER 30S ACROSS THE HIGHER INLAND TERRAIN TO THE
MID AND UPPER 40S ALONG THE COAST.

ONE OTHER ISSUE THAT MAY NEED ATTENTION WILL BE THE LONG EASTERLY
FETCH AND INCREASING ASTRONOMICAL TIDES ON TUESDAY. BOSTON
HARBOR/S HIGH TIDE OCCURS AT 1142 AM AT 11.6 FEET. SURFACE WINDS
LOOK TO REMAIN AT 15 KT OR LESS BUT...WITH THE MAINLY EASTERLY
WIND DIRECTION OVER SEVERAL DAYS...MAY SEE SOME GROUND SWELLS WORK
IN WHICH COULD CAUSE SOME POSSIBLE SPLASHOVER DURING THE MIDDAY
TIDE.

WEDNESDAY AND THURSDAY...HIGH CONFIDENCE IN SYSTEM DEVELOPMENT AND
EFFECTS...LOW TO MODERATE CONFIDENCE ON TIMING DETAILS.

WILL SEE STRONG SURFACE SYSTEM AND ITS ASSOCIATED H5 CUTOFF
VORTEX WILL BE INTENSIFYING DURING THIS TIMEFRAME...WHILE LONG
WAVE TROUGHING WILL BECOME NEGATIVELY TILTED AROUND THE MID ATLC
OR SE U.S. COAST. A SECONDARY LOW...WITH ENERGY AND TROPICAL
MOISTURE WORKING IN FROM THE GULF OF MEXICO...WILL INTENSIFY
DURING WED AS IT WRAPS AROUND THE LARGER UPPER LEVEL CIRCULATION.
LOOKS LIKE THIS LOW WILL PASS W OF THE REGION...BUT WILL BE IN THE
AREA OF BEST MOISTURE CONVERGENCE AND TRANSPORT UP THE EASTERN
SEABOARD. THE 12Z GFS IS BULLISH IN BRINGING SLUG OF HEAVY QPF
ACROSS THE REGION. BOTH THE 12Z EC AND GGEM ALSO SIGNAL THIS
INFLUX THOUGH NOT QUITE AS HIGH ON THE PRECIP AMTS.

STILL NOTING PWATS AT 1.4 TO 1.5 INCHES...RUNNING 2-3SD ABOVE
SEASONAL NORMALS AT ABOUT THE TIME OF THE HEAVIEST PRECIP LATE
WED INTO WED EVENING. ON TOP OF THIS...SOME GOOD INSTABILITY MOVES
ACROSS WITH K INDICES IN THE LOWER-MID 30S AND TOTAL TOTALS IN THE
LOWER 50S. WOULD NOT BE SURPRISED TO SEE SOME ISOLD THUNDER SO
MENTIONED IN THE FORECAST MAINLY DURING WED NIGHT...ALONG WITH
HEAVY RAINFALL FROM THE CONVECTION. LOW LEVEL JET ON ORDER OF
40-55 KT AT H85 AND 50-60 KT AT H925...SO COULD ALSO SEE GUSTY
WINDS ESPECIALLY WITH ANY STORMS. OH...ONE MORE THING...THERE
WILL BE A BRIEF BURST OF MILDER AIR THAT WORKS IN WITH THIS
SYSTEM. EXPECT TEMPS TO RISE TO THE MID 40S WELL INLAND TO THE
MID 50S AT THE COAST...BUT WILL NOT TOP OFF UNTIL CLOSE TO
MIDNIGHT WED NIGHT...WHICH WILL HELP SUPPORT THE INSTABILITY.

MODELS CONTINUE TO SIGNAL FAST MOVEMENT OF THE SURFACE SYSTEM
LATE WED NIGHT...WITH DRY SLOT WORKING ACROSS THE REGION AFTER
MIDNIGHT WITH DRY CONDITIONS BY DAWN ON CHRISTMAS MORNING. WINDS
WILL QUICKLY SHIFT AROUND TO W-SW AND WILL BECOME VERY GUSTY WITH
THE LOW LEVEL JET IN PLACE AND COLDER AIR WRAPPING IN.

MAY HAVE SOME COASTAL FLOODING ISSUES WITH HIGHEST ASTRONOMICAL
TIDES OF THE MONTH OCCUR ON WED AND THU...UP TO 11.7 FT AND 11.5
FT RESPECTIVELY FOR BOSTON. ANY EASTERLY COMPONENT WILL PUSH THE
TIDE ABOVE FLOOD...SO COASTAL FLOODING IS POSSIBLE AS WELL AS
BEACH EROSION ON THE WED TIDE ALONG E FACING BEACHES. THE SOUTH
COASTLINE WILL ALSO HAVE TO BE WATCH CLOSELY ON THU AS WINDS SHIFT
TO W- SW...THOUGH E COASTAL AREAS COULD SEE PROBLEMS WITH
CONTINUED E SWELLS. AS MENTIONED ABOVE...STRONG SOUTHERLY JET
DEVELOPS WED INTO THU AND...WITH ASTRONOMICAL HIGH TIDES...COULD
ALSO SEE MINOR TO MODERATE COASTAL FLOODING. ANOTHER ISSUE IS THE
POTENTIAL PRESSURE FALLS IF THIS SYSTEM STRENGTHENS EVEN
MORE...IT COULD ADD ANOTHER FOOT ONTO THE SURGE.

FRIDAY...LOW CONFIDENCE.

ONCE UPPER LOW AND SURFACE SYSTEM MOVES INTO SOUTHERN CANADA...
EXPECT A RATHER FAST UPPER W FLOW IN PLACE. MAY SEE SOME LEFTOVER
SNOW SHOWERS ACROSS THE E SLOPES OF THE BERKSHIRES. GUSTY W-SW
WINDS CONTINUE AS TEMPS FALL BACK TO MORE SEASONABLE LEVELS.

&&

.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /THROUGH SATURDAY NIGHT/...

TONIGHT...MODERATE CONFIDENCE. CLEARING SKIES AND VFR CONDITIONS
WILL PUSH INTO CENTRAL AND WESTERN AREAS THROUGH MIDNIGHT AS LOW
LEVEL DRY AIR MOVES ACROSS THE REGION. HOWEVER...LOW CLOUDS AND
MVFR CIGS OVER THE OUTER CAPE WILL GRADUALLY BACK IN ACROSS E
COASTAL MA OVERNIGHT.

SATURDAY...MODERATE CONFIDENCE. MVFR CIGS ACROSS SE NEW ENG WILL
EXPAND WEST ACROSS THE REST OF THE COASTAL PLAIN THEN INTO THE
INTERIOR DURING THE AFTERNOON. CT VALLEY SHOULD REMAIN VFR.
SCATTERED RAIN SHOWERS WILL DEVELOP OVER CAPE COD WITH SNOW
SHOWERS INTO E MA BY LATE AFTERNOON.

SATURDAY NIGHT...MODERATE CONFIDENCE. WIDESPREAD MVFR CIGS WITH
POCKETS OF IFR E MA COAST. PERIODS OF LIGHT RAIN OVER CAPE COD
WITH LIGHT SNOW FURTHER INLAND ACROSS E MA. MINOR ACCUM POSSIBLE
ACROSS E MA JUST INLAND FROM THE IMMEDIATE COAST.

KBOS TERMINAL...MODERATE CONFIDENCE IN TAF. VFR TONIGHT...THEN
MVFR CIGS DEVELOP SAT MORNING.

KBDL TERMINAL...MODERATE CONFIDENCE IN TAF.

OUTLOOK...SUNDAY THROUGH WEDNESDAY...

SUNDAY...HIGH CONFIDENCE. MAINLY VFR ACROSS CENTRAL AND WESTERN
AREAS. E MA/RI...MAY SEE LOCAL MVFR CONDITIONS IN RAIN/SNOW
SHOWERS INTO THE AFTERNOON...THEN SLOW IMPROVEMENT FROM W-E.

MONDAY...MODERATE CONFIDENCE. MAINLY VFR.

MONDAY NIGHT-TUESDAY...MODERATE CONFIDENCE. DEVELOPING RAIN OR
MIXED PRECIP FROM S-N MON NIGHT WITH MVFR CONDITIONS. MAY SEE
-FZRA/-PL ACROSS CENTRAL AND WESTERN AREAS AROUND OR AFTER
MIDNIGHT INTO TUE MORNING THEN SHOULD CHANGE TO RAIN AS TEMPS
RISE. E-SE WINDS GUSTING TO 20-25 KT ALONG S COAST TUE.

TUESDAY NIGHT-WEDNESDAY...MODERATE CONFIDENCE. MVFR-IFR
CONDITIONS IN RAIN...HEAVY AT TIMES DURING WED. ISOLD THUNDER
POSSIBLE WED AFTERNOON/EVENING. E WINDS SHIFTING TO SE-S LATE TUE
NIGHT/WED WITH GUSTS UP TO 25-30 KT...HIGHEST ACROSS CAPE COD AND
THE ISLANDS.

&&

.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.

HIGH PRESSURE BUILDING EAST TO MAINE AND THE MARITIMES WILL KEEP
WINDS/SEAS BELOW SCA THRESHOLDS THROUGH SATURDAY NIGHT...WITH WIND
SPEEDS LESS THAN 20 KT. NORTHERLY WINDS TONIGHT BECOMING NE
SAT/SAT NIGHT. GUSTS UP TO 20 KT POSSIBLE SAT NIGHT ACROSS NE MA
COASTAL WATERS.

OUTLOOK...SUNDAY THROUGH WEDNESDAY...MODERATE TO HIGH CONFIDENCE.

SUNDAY THROUGH MONDAY NIGHT...WINDS AND SEAS BELOW SMALL CRAFT
CRITERIA. E WINDS GUSTING UP TO 20 KT MON NIGHT.

TUESDAY-WEDNESDAY...E WINDS INCREASE...GUSTING TO 30 KT TUE THEN
SHIFT TO SE GUSTING TO 30-35 KT WED...HIGHEST ON THE OUTER
WATERS. SEAS BUILD UP TO 7-11 FT BY WED. GALES ON THE OUTER WATERS
LIKELY.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...KJC/EVT
NEAR TERM...KJC/EVT
SHORT TERM...KJC
LONG TERM...EVT
AVIATION...KJC/EVT
MARINE...KJC/EVT





000
FXUS61 KBOX 192226
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
526 PM EST FRI DEC 19 2014

.SYNOPSIS...
A WEAK DISTURBANCE AND ONSHORE FLOW WILL RESULT IN A PERIOD OF
LIGHT SNOW/RAIN SHOWERS MAINLY ACROSS EASTERN NEW ENGLAND THIS
WEEKEND INTO EARLY NEXT WEEK. LOW PRESSURE WILL PASS SOUTH OF NEW
ENGLAND...BRINGING ANOTHER PERIOD OF PRECIPITATION. A MUCH
STRONGER STORM PASSING WEST OF NEW ENGLAND WILL BRING HEAVY
RAINFALL...GUSTY WINDS AND COASTAL FLOODING CONCERNS TO THE
REGION WEDNESDAY INTO WEDNESDAY EVENING. DRY BUT VERY WINDY
CONDITIONS FOLLOW FOR CHRISTMAS DAY INTO FRIDAY.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
PARTIAL CLEARING PUSHING SOUTH ACROSS NE MA THIS AFTERNOON AS LOW
LEVEL DRIER AIR MOVES IN FROM THE N. NAM IS HANDLING THIS LOW
LEVEL DRY AIR FAIRLY WELL AND SHOWS DRIER AIR OVERSPREADING MUCH
OF CENTRAL AND WESTERN ZONES TONIGHT WHICH SHOULD LEAD TO SOME
CLEARING. HOWEVER...LOW LEVEL MOISTURE WILL REMAIN LOCKED IN
ACROSS CAPE COD AND BACK IN ACROSS SE MA OVERNIGHT. IT LOOKS
MOSTLY DRY THROUGH THE NIGHT. MIN TEMPS MOSTLY IN THE 20S...WITH
LOWER 30S OUTER CAPE/ACK. TEMPS COULD DROP INTO THE TEENS N AND W
MA IF THERE IS SUFFICIENT CLEARING.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
HIGH PRES BUILDS ACROSS N MAINE AND THE MARITIMES WITH LOW LEVEL
FLOW VEERING TO THE E WHILE SFC WINDS MOSTLY NE. THIS WILL RESULT
IN LOW CLOUDS EXPANDING WEST ACROSS SNE DURING SAT AS LOW LEVEL
MOISTURE INCREASES. NOT REALLY LOOKING AT A PURE OCEAN EFFECT
SITUATION AS INSTABILITY IS MARGINAL. HOWEVER...HI-RES GUIDANCE
PICKING UP ON A DEVELOPING COASTAL FRONT ACROSS CAPE COD VICINITY
WITH E WINDS TO THE E OF THE BOUNDARY AND N/NE WINDS TO THE WEST.
LOW LEVEL FORCING COMBINED WITH DEEPENING MOISTURE AS MID LEVEL
SHORTWAVE MOVES IN FROM THE WEST WILL RESULT IN RAIN/SNOW SHOWERS
EXPANDING WEST FROM CAPE COD INTO EASTERN HALF NEW ENG. WHILE SOME
LIGHT PRECIP IS POSSIBLE IN THE MORNING...ESPECIALLY CAPE
COD...BULK OF PRECIP OCCURS LATER SAT INTO SAT NIGHT ASSOCD WITH
DEEPER MOISTURE AND LOW LEVEL LIFT FROM THE COASTAL FRONT/INVERTED
TROF.

PTYPE/SNOW ACCUM...
LOOKING AT MOSTLY RAIN FOR CAPE/ISLANDS AND POSSIBLY INTO SE
COASTAL PLYMOUTH COUNTY WHERE E WINDS WILL SUFFICIENTLY WARM THE
BOUNDARY LAYER KEEPING TEMPS IN THE MID/UPPER 30S. HOWEVER...JUST
INLAND AND NORTH FROM THE IMMEDIATE SE COAST AND WEST OF THE
COASTAL FRONT WHERE WINDS ARE FORECAST TO BE MORE
NORTHERLY...EXPECT MOSTLY SNOW ALTHOUGH THERE COULD BE A MIX AT
THE START. FREEZING DRIZZLE IS NOT LIKELY AS THE COLUMN MOISTENS
LATE SAT INTO SAT NIGHT WITH TEMPS -10C IN THE MOIST LAYER WHICH
IS COLD ENOUGH FOR ICE CRYSTAL PRODUCTION.

NAM IS PICKING UP ON SOME ENHANCEMENT IN N PLYMOUTH COUNTY INTO
NORFOLK COUNTY WITH QPF UP TO A THIRD OF AN INCH. THIS LIKELY
ASSOCD WITH A 20-25 KT E/NE LOW LEVEL JET THAT THE NAM IS
FORECASTING. HOWEVER...THIS MIGHT BE OVERDONE AS HI-RES WRF QPF
IS LESS AND OTHER MODELS ARE WEAKER WITH THE LOW LEVEL NE FLOW.
DONT WANT TO COMPLETELY IGNORE THE NAM AS IT SOMETIMES CAN PICK
UP ON HEAVIER MESOSCALE PRECIP IN THESE SITUATIONS SO USED A
BLEND OF NAM/GFS QPF TO TEMPER NAM OUTPUT. MAINLY LOOKING AT A
COATING TO AN INCH FOR EASTERN NEW ENG...HIGHEST AMOUNTS ACROSS E
MA AWAY FROM THE IMMEDIATE COAST. LOCALIZED AMOUNTS UP TO 2 INCHES
POSSIBLE...ESPECIALLY JUST SW OF BOSTON.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
HIGHLIGHTS...

* SCT SNOW/RAIN SHOWERS LINGER ON SUNDAY WITH SLIGHTLY BELOW
  NORMAL TEMPS
* WEAK LOW PRES WILL PASS SOUTH OF NEW ENGLAND MONDAY NIGHT AND
  TUESDAY BRINGING LIGHT PRECIPITATION...AS WELL AS A WINTRY MIX
  TO THE INTERIOR
* STRENGTHENING LOW PRES WILL WRAP UP AROUND ANOMALOUS VORTEX
  ACROSS THE GREAT LAKES...BRINGING HEAVY RAIN...GUSTY WINDS AND
  COASTAL CONCERNS TO THE REGION LATE WEDNESDAY INTO CHRISTMAS EVE

OVERVIEW AND MODEL PREFERENCES...

MEDIUM RANGE MODEL SUITE CONTINUES TO SIGNAL DEVELOPMENT OF
AMPLIFIED UPPER LEVEL PATTERN ACROSS NORTH AMERICA THROUGH THIS
FORECAST PERIOD. AN H5 CUTOFF VORTEX WILL DOMINATE ACROSS THE GREAT
LAKES AND ITS EXTENDING LONG WAVE TROUGH WRAPPING AROUND TO THE
EASTERN SEABOARD AS IT BECOMES NEGATIVELY TILTED. WITH OVERALL SW
FLOW IN PLACE...WILL SEE WEAK SYSTEMS WORK TOWARD THE REGION EARLY
IN THE PERIOD. A STRONGER LOW WILL DEVELOP NEAR OR JUST OFF THE SE
U.S. COAST AROUND EARLY WED AND PASS W OF THE REGION WED NIGHT...
BRINGING GUSTY WINDS...HEAVY RAINFALL WITH A FEW THUNDERSTORMS
POSSIBLE AS WELL AS POSSIBLE COASTAL CONCERNS.

WHILE THERE ARE STILL SOME TIMING AND TRACK VARIANCES WITH THE MID
WEEK SYSTEM...MODELS AND ENSEMBLES REMAIN IN GOOD AGREEMENT WITH THE
DEVELOPMENT OF THIS AMPLIFIED PATTERN...AS WELL AS THE UPPER
LEVEL VORTEX ACROSS THE GREAT LAKES AND SURFACE SYSTEM THAT WILL
MORE THAN LIKELY AFFECT THE REGION DURING THE WEDNESDAY-WEDNESDAY
NIGHT TIMEFRAME.

USED A BLEND OF AVAILABLE GUIDANCE AS WELL AS GFS/EC ENSEMBLE MEANS
FOR THIS FORECAST WHICH SHOWED GOOD CONTINUITY TO THE PREVIOUS
FORECAST.

DETAILS...

SUNDAY AND MONDAY...MODERATE TO HIGH CONFIDENCE.

LEFTOVER MOISTURE WILL LINGER SUNDAY MORNING WITH LIGHT RAIN
AND/OR SNOW SHOWERS MAINLY ACROSS E MA/RI THOUGH COULD SEE SOME
ISOLD ACTIVITY FURTHER INLAND AS COASTAL FRONT WEAKENS. RIDGING
WILL NOSE DOWN THE COAST FROM HIGH PRES OVER NORTHERN NEW ENGLAND
AND QUEBEC SUN NIGHT INTO MONDAY...BRINGING A BRIEF DRY PERIOD
THOUGH CLOUDS WILL LINGER WITH A CONTINUED ONSHORE WIND
FLOW...ALBEIT WEAK. EXPECT TEMPS TO RUN NEAR OR SLIGHTLY BELOW
NORMAL...THOUGH WILL BE A BIT MILDER ALONG THE S COAST DURING MON.

BY LATE MONDAY...MAY START TO SEE SOME PRECIP WORK INTO THE LOWER
CT VALLEY AS A WEAK LOW MOVES OFF THE MID ATLC COAST.

MONDAY NIGHT-TUESDAY...MODERATE CONFIDENCE.

WEAK COASTAL LOW WILL PASS OFF THE SOUTH COAST...BUT WILL BRING
ENOUGH MOISTURE AND LIFT FOR PRECIP TO MOVE IN FROM S-N. TEMPS
WILL STILL BE CHILLY THOUGH...ESPECIALLY INLAND THERE THE COLDER
AIR WILL BE TRAPPED... SO WILL SEE SOME MIXED PRECIP /SLEET AND/OR
FREEZING RAIN/. EVEN THOUGH QPF WILL BE LIGHT...COULD BE ENOUGH TO
CAUSE SOME LIGHT GLAZING PROBLEMS LATE MON NIGHT INTO TUE MORNING.
STILL SOME TIMING ISSUES AS WELL AS QUESTIONS WITH THERMAL
PROFILES...BUT MAY NEED WINTER WX HEADLINES DURING THIS TIMEFRAME.
SOMETHING TO MONITOR CLOSELY.

BY TUE AFTERNOON...TEMPS SHOULD RECOVER WITH GRADUALLY INCREASING
E-SE WINDS...SO WILL SEE ALL RAIN BY THEN. HIGHS ON TUE WILL
RANGE FROM THE UPPER 30S ACROSS THE HIGHER INLAND TERRAIN TO THE
MID AND UPPER 40S ALONG THE COAST.

ONE OTHER ISSUE THAT MAY NEED ATTENTION WILL BE THE LONG EASTERLY
FETCH AND INCREASING ASTRONOMICAL TIDES ON TUESDAY. BOSTON
HARBOR/S HIGH TIDE OCCURS AT 1142 AM AT 11.6 FEET. SURFACE WINDS
LOOK TO REMAIN AT 15 KT OR LESS BUT...WITH THE MAINLY EASTERLY
WIND DIRECTION OVER SEVERAL DAYS...MAY SEE SOME GROUND SWELLS WORK
IN WHICH COULD CAUSE SOME POSSIBLE SPLASHOVER DURING THE MIDDAY
TIDE.

WEDNESDAY AND THURSDAY...HIGH CONFIDENCE IN SYSTEM DEVELOPMENT AND
EFFECTS...LOW TO MODERATE CONFIDENCE ON TIMING DETAILS.

WILL SEE STRONG SURFACE SYSTEM AND ITS ASSOCIATED H5 CUTOFF
VORTEX WILL BE INTENSIFYING DURING THIS TIMEFRAME...WHILE LONG
WAVE TROUGHING WILL BECOME NEGATIVELY TILTED AROUND THE MID ATLC
OR SE U.S. COAST. A SECONDARY LOW...WITH ENERGY AND TROPICAL
MOISTURE WORKING IN FROM THE GULF OF MEXICO...WILL INTENSIFY
DURING WED AS IT WRAPS AROUND THE LARGER UPPER LEVEL CIRCULATION.
LOOKS LIKE THIS LOW WILL PASS W OF THE REGION...BUT WILL BE IN THE
AREA OF BEST MOISTURE CONVERGENCE AND TRANSPORT UP THE EASTERN
SEABOARD. THE 12Z GFS IS BULLISH IN BRINGING SLUG OF HEAVY QPF
ACROSS THE REGION. BOTH THE 12Z EC AND GGEM ALSO SIGNAL THIS
INFLUX THOUGH NOT QUITE AS HIGH ON THE PRECIP AMTS.

STILL NOTING PWATS AT 1.4 TO 1.5 INCHES...RUNNING 2-3SD ABOVE
SEASONAL NORMALS AT ABOUT THE TIME OF THE HEAVIEST PRECIP LATE
WED INTO WED EVENING. ON TOP OF THIS...SOME GOOD INSTABILITY MOVES
ACROSS WITH K INDICES IN THE LOWER-MID 30S AND TOTAL TOTALS IN THE
LOWER 50S. WOULD NOT BE SURPRISED TO SEE SOME ISOLD THUNDER SO
MENTIONED IN THE FORECAST MAINLY DURING WED NIGHT...ALONG WITH
HEAVY RAINFALL FROM THE CONVECTION. LOW LEVEL JET ON ORDER OF
40-55 KT AT H85 AND 50-60 KT AT H925...SO COULD ALSO SEE GUSTY
WINDS ESPECIALLY WITH ANY STORMS. OH...ONE MORE THING...THERE
WILL BE A BRIEF BURST OF MILDER AIR THAT WORKS IN WITH THIS
SYSTEM. EXPECT TEMPS TO RISE TO THE MID 40S WELL INLAND TO THE
MID 50S AT THE COAST...BUT WILL NOT TOP OFF UNTIL CLOSE TO
MIDNIGHT WED NIGHT...WHICH WILL HELP SUPPORT THE INSTABILITY.

MODELS CONTINUE TO SIGNAL FAST MOVEMENT OF THE SURFACE SYSTEM
LATE WED NIGHT...WITH DRY SLOT WORKING ACROSS THE REGION AFTER
MIDNIGHT WITH DRY CONDITIONS BY DAWN ON CHRISTMAS MORNING. WINDS
WILL QUICKLY SHIFT AROUND TO W-SW AND WILL BECOME VERY GUSTY WITH
THE LOW LEVEL JET IN PLACE AND COLDER AIR WRAPPING IN.

MAY HAVE SOME COASTAL FLOODING ISSUES WITH HIGHEST ASTRONOMICAL
TIDES OF THE MONTH OCCUR ON WED AND THU...UP TO 11.7 FT AND 11.5
FT RESPECTIVELY FOR BOSTON. ANY EASTERLY COMPONENT WILL PUSH THE
TIDE ABOVE FLOOD...SO COASTAL FLOODING IS POSSIBLE AS WELL AS
BEACH EROSION ON THE WED TIDE ALONG E FACING BEACHES. THE SOUTH
COASTLINE WILL ALSO HAVE TO BE WATCH CLOSELY ON THU AS WINDS SHIFT
TO W- SW...THOUGH E COASTAL AREAS COULD SEE PROBLEMS WITH
CONTINUED E SWELLS. AS MENTIONED ABOVE...STRONG SOUTHERLY JET
DEVELOPS WED INTO THU AND...WITH ASTRONOMICAL HIGH TIDES...COULD
ALSO SEE MINOR TO MODERATE COASTAL FLOODING. ANOTHER ISSUE IS THE
POTENTIAL PRESSURE FALLS IF THIS SYSTEM STRENGTHENS EVEN
MORE...IT COULD ADD ANOTHER FOOT ONTO THE SURGE.

FRIDAY...LOW CONFIDENCE.

ONCE UPPER LOW AND SURFACE SYSTEM MOVES INTO SOUTHERN CANADA...
EXPECT A RATHER FAST UPPER W FLOW IN PLACE. MAY SEE SOME LEFTOVER
SNOW SHOWERS ACROSS THE E SLOPES OF THE BERKSHIRES. GUSTY W-SW
WINDS CONTINUE AS TEMPS FALL BACK TO MORE SEASONABLE LEVELS.


&&

.AVIATION /00Z 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 SATURDAY/...

THROUGH 00Z...LOW VFR AND MVFR CIGS WILL PERSIST...BUT BECOMING
VFR ALONG THE E MA COAST AS CLEARING MOVES IN FROM THE N.

TONIGHT...MODERATE CONFIDENCE. EXPECT PARTIAL CLEARING AND
BECOMING VFR DURING THE NIGHT AS LOW LEVEL DRY AIR MOVES SOUTH
ACROSS THE REGION. HOWEVER...LOW CLOUDS AND MVFR CIGS OVER THE
OUTER CAPE WILL GRADUALLY BACK IN ACROSS SE MA OVERNIGHT.

SATURDAY...MODERATE CONFIDENCE. MVFR CIGS ACROSS SE NEW ENG WILL
EXPAND WEST ACROSS THE REST OF THE COASTAL PLAIN THEN INTO THE
INTERIOR DURING THE AFTERNOON. CT VALLEY SHOULD REMAIN VFR.
SCATTERED RAIN SHOWERS WILL DEVELOP OVER CAPE COD WITH SNOW
SHOWERS INTO E MA BY LATE AFTERNOON.

SATURDAY NIGHT...MODERATE CONFIDENCE. WIDESPREAD MVFR CIGS WITH
POCKETS OF IFR E MA COAST. PERIODS OF LIGHT RAIN OVER CAPE COD
WITH LIGHT SNOW FURTHER INLAND ACROSS E MA. MINOR ACCUM POSSIBLE
ACROSS E MA JUST INLAND FROM THE IMMEDIATE COAST.

KBOS TERMINAL...MODERATE CONFIDENCE IN TAF. EXPECT VFR
TONIGHT...BEFORE MVFR CIGS DEVELOP SAT MORNING.

KBDL TERMINAL...MODERATE CONFIDENCE IN TAF.

OUTLOOK...SUNDAY THROUGH WEDNESDAY...

SUNDAY...HIGH CONFIDENCE. MAINLY VFR ACROSS CENTRAL AND WESTERN
AREAS. E MA/RI...MAY SEE LOCAL MVFR CONDITIONS IN RAIN/SNOW
SHOWERS INTO THE AFTERNOON...THEN SLOW IMPROVEMENT FROM W-E.

MONDAY...MODERATE CONFIDENCE. MAINLY VFR.

MONDAY NIGHT-TUESDAY...MODERATE CONFIDENCE. DEVELOPING RAIN OR
MIXED PRECIP FROM S-N MON NIGHT WITH MVFR CONDITIONS. MAY SEE
-FZRA/-PL ACROSS CENTRAL AND WESTERN AREAS AROUND OR AFTER
MIDNIGHT INTO TUE MORNING THEN SHOULD CHANGE TO RAIN AS TEMPS
RISE. E-SE WINDS GUSTING TO 20-25 KT ALONG S COAST TUE.

TUESDAY NIGHT-WEDNESDAY...MODERATE CONFIDENCE. MVFR-IFR
CONDITIONS IN RAIN...HEAVY AT TIMES DURING WED. ISOLD THUNDER
POSSIBLE WED AFTERNOON/EVENING. E WINDS SHIFTING TO SE-S LATE TUE
NIGHT/WED WITH GUSTS UP TO 25-30 KT...HIGHEST ACROSS CAPE COD AND
THE ISLANDS.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /TODAY THROUGH SATURDAY NIGHT/...HIGH CONFIDENCE.

HIGH PRESSURE BUILDING EAST N MAINE AND THE MARITIMES WILL KEEP
WINDS/SEAS BELOW SCA THRESHOLDS THROUGH SATURDAY NIGHT...WITH
WIND SPEEDS LESS THAN 20 KT. NORTHERLY WINDS TONIGHT BECOMING NE
SAT/SAT NIGHT. GUSTS UP TO 20 KT POSSIBLE SAT NIGHT ACROSS NE MA
COASTAL WATERS.

OUTLOOK...SUNDAY THROUGH WEDNESDAY...MODERATE TO HIGH CONFIDENCE.

SUNDAY THROUGH MONDAY NIGHT...WINDS AND SEAS BELOW SMALL CRAFT
CRITERIA. E WINDS GUSTING UP TO 20 KT MON NIGHT.

TUESDAY-WEDNESDAY...E WINDS INCREASE...GUSTING TO 30 KT TUE THEN
SHIFT TO SE GUSTING TO 30-35 KT WED HIGHEST ON THE OUTER WATERS.
SEAS BUILD UP TO 7-11 FT BY WED. GALES ON THE OUTER WATERS
LIKELY.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...KJC/EVT
NEAR TERM...KJC
SHORT TERM...KJC
LONG TERM...EVT
AVIATION...KJC/EVT
MARINE...KJC/EVT





000
FXUS61 KBOX 192030
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
330 PM EST FRI DEC 19 2014

.SYNOPSIS...
A WEAK DISTURBANCE AND ONSHORE FLOW WILL RESULT IN A PERIOD OF
LIGHT SNOW/RAIN SHOWERS MAINLY ACROSS EASTERN NEW ENGLAND THIS
WEEKEND. LOW PRESSURE WILL PASS NEAR THE REGION ON
TUESDAY...BRINGING A PERIOD OF PRECIPITATION. A MUCH STRONGER
STORM IS LIKELY TO BRING HEAVY RAIN...WIND AND COASTAL FLOODING
CONCERNS TO SOUTHERN NEW ENGLAND WEDNESDAY INTO WEDNESDAY EVENING.
DRY BUT VERY WINDY CONDITIONS FOLLOW FOR CHRISTMAS DAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
PARTIAL CLEARING PUSHING SOUTH ACROSS NE MA THIS AFTERNOON AS LOW
LEVEL DRIER AIR MOVES IN FROM THE N. NAM IS HANDLING THIS LOW
LEVEL DRY AIR FAIRLY WELL AND SHOWS DRIER AIR OVERSPREADING MUCH
OF CENTRAL AND WESTERN ZONES TONIGHT WHICH SHOULD LEAD TO SOME
CLEARING. HOWEVER...LOW LEVEL MOISTURE WILL REMAIN LOCKED IN
ACROSS CAPE COD AND BACK IN ACROSS SE MA OVERNIGHT. IT LOOKS
MOSTLY DRY THROUGH THE NIGHT. MIN TEMPS MOSTLY IN THE 20S...WITH
LOWER 30S OUTER CAPE/ACK. TEMPS COULD DROP INTO THE TEENS N AND W
MA IF THERE IS SUFFICIENT CLEARING.

&&

.SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/...

HIGH PRES BUILDS ACROSS N MAINE AND THE MARITIMES WITH LOW LEVEL
FLOW VEERING TO THE E WHILE SFC WINDS MOSTLY NE. THIS WILL RESULT
IN LOW CLOUDS EXPANDING WEST ACROSS SNE DURING SAT AS LOW LEVEL
MOISTURE INCREASES. NOT REALLY LOOKING AT A PURE OCEAN EFFECT
SITUATION AS INSTABILITY IS MARGINAL. HOWEVER...HI-RES GUIDANCE
PICKING UP ON A DEVELOPING COASTAL FRONT ACROSS CAPE COD VICINITY
WITH E WINDS TO THE E OF THE BOUNDARY AND N/NE WINDS TO THE WEST.
LOW LEVEL FORCING COMBINED WITH DEEPENING MOISTURE AS MID LEVEL
SHORTWAVE MOVES IN FROM THE WEST WILL RESULT IN RAIN/SNOW SHOWERS
EXPANDING WEST FROM CAPE COD INTO EASTERN HALF NEW ENG. WHILE SOME
LIGHT PRECIP IS POSSIBLE IN THE MORNING...ESPECIALLY CAPE
COD...BULK OF PRECIP OCCURS LATER SAT INTO SAT NIGHT ASSOCD WITH
DEEPER MOISTURE AND LOW LEVEL LIFT FROM THE COASTAL FRONT/INVERTED
TROF.

PTYPE/SNOW ACCUM...
LOOKING AT MOSTLY RAIN FOR CAPE/ISLANDS AND POSSIBLY INTO SE
COASTAL PLYMOUTH COUNTY WHERE E WINDS WILL SUFFICIENTLY WARM THE
BOUNDARY LAYER KEEPING TEMPS IN THE MID/UPPER 30S. HOWEVER...JUST
INLAND AND NORTH FROM THE IMMEDIATE SE COAST AND WEST OF THE
COASTAL FRONT WHERE WINDS ARE FORECAST TO BE MORE
NORTHERLY...EXPECT MOSTLY SNOW ALTHOUGH THERE COULD BE A MIX AT
THE START. FREEZING DRIZZLE IS NOT LIKELY AS THE COLUMN MOISTENS
LATE SAT INTO SAT NIGHT WITH TEMPS -10C IN THE MOIST LAYER WHICH
IS COLD ENOUGH FOR ICE CRYSTAL PRODUCTION.

NAM IS PICKING UP ON SOME ENHANCEMENT IN N PLYMOUTH COUNTY INTO
NORFOLK COUNTY WITH QPF UP TO A THIRD OF AN INCH. THIS LIKELY
ASSOCD WITH A 20-25 KT E/NE LOW LEVEL JET THAT THE NAM IS
FORECASTING. HOWEVER...THIS MIGHT BE OVERDONE AS HI-RES WRF QPF
IS LESS AND OTHER MODELS ARE WEAKER WITH THE LOW LEVEL NE FLOW.
DONT WANT TO COMPLETELY IGNORE THE NAM AS IT SOMETIMES CAN PICK
UP ON HEAVIER MESOSCALE PRECIP IN THESE SITUATIONS SO USED A
BLEND OF NAM/GFS QPF TO TEMPER NAM OUTPUT. MAINLY LOOKING AT A
COATING TO AN INCH FOR EASTERN NEW ENG...HIGHEST AMOUNTS ACROSS E
MA AWAY FROM THE IMMEDIATE COAST. LOCALIZED AMOUNTS UP TO 2 INCHES
POSSIBLE...ESPECIALLY JUST SW OF BOSTON.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
HIGHLIGHTS...

* SCT SNOW/RAIN SHOWERS SUNDAY WITH AVG TEMPS
* WEAK WAVE OF LOW PRESSURE MON NIGHT/TUESDAY COULD BRING WINTRY
  MIX TO INTERIOR
* ANOMALOUS SYSTEM ACROSS THE GREAT LAKES WILL BRING HEAVY
  RAIN...GUSTY WINDS AND COASTAL CONCERNS AROUND CHRISTMAS EVE

OVERVIEW...

OVERALL 00Z GUIDANCE IS IN AGREEMENT SYNOPTICALLY WITH ISSUES ON
TIMING AND SMALLER SCALE FEATURES. AN AMPLIFIED MID-UPPER LEVEL
TROUGH AND PCPN FOCUSING LEAD SURFACE LOW/FRONTAL SYSTEM DEVELOPS
OVER THE CENTRAL US BY EARLY NEXT WEEK. THE SUPPORTING AND
INCREASINGLY NEG-TILT TROUGH ALOFT WORKS OVER THE ERN US AND OUT
THROUGH THE NERN STATES INTO DAYS 5/6 WED/THU.  MODELS/ENSEMBLES
HAVE BEEN FAIRLY CONSISTENT IN RECENT RUNS ON THIS AMPLIFIED PATTERN
AND THE MOST RECENT GEFS/ECMWF ENSEMBLE GUIDANCE SHOW GOOD
CORRELATION TO NEXT THURSDAY.

DURING THIS SYNOPTIC TRANSITION...HIGH PRESSURE AND UPPER LEVEL
RIDGE WILL BE OVER THE NORTHEAST SATURDAY NIGHT BEFORE DEPARTING
LATE SUNDAY. LONGWAVE DIGGING TROUGH OVER THE CENTRAL CONUS WILL
PUSH A FEW SHORTWAVES THROUGH THE FLOW. FIRST ONE DEVELOPS A WEAK
COASTAL LOW MOVING TOWARDS THE REGION LATE MONDAY INTO TUESDAY.
THERE IS STILL SOME UNCERTAINTY WITH THE LOCATION OF THIS SYSTEM
BUT APPEARS THAT THERE WILL BE SNOW/WINTRY MIX IN THE INTERIOR. AS
THIS SYSTEM DEPARTS APPEARS AN ANOMALOUS LOW OVER THE GREAT LAKES
WILL DEVELOP A SECONDARY LOW /DOUBLE BARREL LOW/ CLOSER TO NEW
ENGLAND...PER ENSEMBLE GUIDANCE. STILL A GOOD AMOUNT OF SPREAD BUT
IF THIS DOUBLE LOW DOES DEVELOP THEN THE RAIN AND WIND ASPECT OF THE
SYSTEM INCREASES...DETAILS BELOW. STILL SOME UNCERTAINTY WITH THIS
PARTICULAR SYSTEM BUT WITH 2 TO 3 SD AWAY AND GENERAL MODEL
AGREEMENT HAVE HIGHER CONFIDENCE THIS SYSTEM WILL IMPACT SOUTHERN
NEW ENGLAND.

DETAILS...

MONDAY INTO TUESDAY...MODERATE CONFIDENCE.

WEAK COASTAL LOW PRESSURE SYSTEM WILL DEVELOP AND MOVE CLOSE TO THE
SOUTHERN NEW ENGLAND COASTLINE. THERE IS STILL DESCENT MODEL SPREAD
ON THE EXACT LOW TRACK BUT APPEARS THAT IT DOES WEAKEN AS IT
APPROACHES FROM THE MID-ATLANTIC. REGARDLESS THERE COULD ALLOW FOR
SHALLOW COLD AIR FROM THE DEPARTING TO HIGH TO STAY TRAP AND WITH
WARM AIR ALOFT MOVING INTO THE REGION...COULD SEE SNOW OR WINTRY
PRECIP ESP ACROSS THE HIGHER TERRAIN LATE MONDAY INTO TUESDAY
MORNING. BECAUSE OF THE MODEL SPREAD STILL HAVE DETAILS TO WORK OUT
BUT SOMETHING TO WATCH CLOSELY.

TEMPERATURES WILL SLOWLY BEGIN TO WARM ON TUESDAY AS SOUTHERLY FLOW
BECOMES DOMINATE OUT AHEAD OF STRONGER SYSTEM TO THE EAST. EASTERLY
FLOW WILL CONTINUE TO DOMINATE AT THE SURFACE WITH A EASTERLY LLJ
STRENGTHEN ABOUT 20-30KTS. TUESDAYS HIGH TIDE AT BOSTON WILL BE 11.6
DURING THE LATE MORNING...AND WITH PERSISTENT EASTERLY WINDS
ANTICIPATE AT LEAST MINOR COASTAL FLOODING. IF THIS SURFACE LOW
STRENGTHENS AND THE EASTERLY FLOW INCREASES THEN THE MASS EAST
COASTLINE WILL HAVE TO BE WATCHED CLOSELY DURING THE TUESDAY HIGH
TIDE.

WEDNESDAY INTO THURSDAY...HIGH CONFIDENCE IN SYSTEM LOW CONFIDENCE
ON DETAILS.

STRONG ANOMALOUS SYSTEM WILL STRENGTHEN OVER THE GREAT
LAKES...DEVELOPING A POTENTIAL SECONDARY SURFACE LOW JUST WEST OF
SOUTHERN NEW ENGLAND. STILL A LOT OF DETAILS TO WORK OUT AS THIS
SYSTEM IS STILL 5+ DAYS AWAY...HOWEVER ENSEMBLES SHOW THAT THIS
SYSTEM IS AROUND 2 TO 3 STANDARD DEVIATIONS ALLOWING FOR INCREASING
CONFIDENCE THAT A POTENT STORM WILL OCCUR. LATEST 00Z GUIDANCE SHOWS
THAT MOST PRECIP WILL BE LIQUID WITH A DEEP SUBTROPICAL CONNECTION
BACK ACROSS MEXICO... PW ANOMALIES FORECAST TO RISE TO BETWEEN +1 TO
+3 /OR HIGHER/...AND TEMPERATURES WELL ABOVE AVERAGE. IN FACT WE MAY
BE CLOSE AT BREAKING RECORD HIGH TEMPS IF TEMPS WARM TO 60F OR ABOVE
ON CHRISTMAS EVE.  AS THE SYSTEM WRAPS UP INTO CANADA...COLD AIR
ADVECTION SHOULD CIRCULATE AROUND AND BEGIN A TRANSITION FROM
SOUTHWEST TO NORTHEAST IN TURNING P-TYPE TO SNOW. HOWEVER LATEST
GUIDANCE DOES SHOW A QUICK MOVING DRY SLOT SO SNOWFALL WILL STRUGGLE
DUE TO LACK OF MOISTURE.

THIS SYSTEM IS QUITE POTENT SO WE WILL NEED TO WATCH FOR POTENTIAL
HAZARDS. CURRENTLY THINK THAT WE COULD SEE POSSIBLE URBAN FLOODING
ISSUES AS WELL AS WIND ISSUES. GUIDANCE RIGHT NOW IS SHOWING A 45 TO
55 KT JET AT 925 MB WHICH MAY WARRANT WIND ADVISORIES BUT THIS
SYSTEM COULD STRENGTHEN EVEN MORE SO A STRONGER JET IS POSSIBLE.

LASTLY COASTAL FLOODING ISSUES WILL NEED TO BE ADDRESS AS HIGH TIDE
ON WED AND THUS ARE 11.7 AND 11.5 RESPECTIVELY FOR BOSTON. ANY
EASTERLY COMPONENT WILL PUSH THE TIDE ABOVE FLOOD SO COASTAL
FLOODING IS POSSIBLE AS WELL AS BEACH EROSION. THE SOUTH COASTLINE
WILL ALSO HAVE TO BE WATCH CLOSELY. A VERY STRONG SOUTHERLY JET
WILL DEVELOP WED INTO THURSDAY AND WITH ASTRONOMICAL HIGH TIDE
COULD ALSO SEE MINOR TO MODERATE COASTAL FLOODING. ANOTHER ISSUE
IS THE POTENTIAL PRESSURE FALLS IF THIS SYSTEM STRENGTHENS EVEN
MORE...IT COULD ADD ANOTHER FOOT ONTO THE SURGE.

FRIDAY...LOW CONFIDENCE.

ONCE UPPER LOW MOVES INTO SOUTHERN CANADA...EXPECT A RATHER FAST
UPPER W FLOW IN PLACE. MAY SEE LEFTOVER SNOW SHOWERS BUT TEMPS WILL
FALL BACK CLOSE TO SEASONAL NORMS.

&&

.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /TODAY THROUGH SATURDAY/...

THROUGH 00Z...LOW VFR AND MVFR CIGS WILL PERSIST...BUT BECOMING
VFR ALONG THE E MA COAST AS CLEARING MOVES IN FROM THE N.

TONIGHT...MODERATE CONFIDENCE. EXPECT PARTIAL CLEARING AND
BECOMING VFR DURING THE NIGHT AS LOW LEVEL DRY AIR MOVES SOUTH
ACROSS THE REGION. HOWEVER...LOW CLOUDS AND MVFR CIGS OVER THE
OUTER CAPE WILL GRADUALLY BACK IN ACROSS SE MA OVERNIGHT.

SATURDAY...MODERATE CONFIDENCE. MVFR CIGS ACROSS SE NEW ENG WILL
EXPAND WEST ACROSS THE REST OF THE COASTAL PLAIN THEN INTO THE
INTERIOR DURING THE AFTERNOON. CT VALLEY SHOULD REMAIN VFR.
SCATTERED RAIN SHOWERS WILL DEVELOP OVER CAPE COD WITH SNOW
SHOWERS INTO E MA BY LATE AFTERNOON.

SATURDAY NIGHT...MODERATE CONFIDENCE. WIDESPREAD MVFR CIGS WITH
POCKETS OF IFR E MA COAST. PERIODS OF LIGHT RAIN OVER CAPE COD
WITH LIGHT SNOW FURTHER INLAND ACROSS E MA. MINOR ACCUM POSSIBLE
ACROSS E MA JUST INLAND FROM THE IMMEDIATE COAST.

KBOS TERMINAL...MODERATE CONFIDENCE IN TAF. EXPECT VFR
TONIGHT...BEFORE MVFR CIGS DEVELOP SAT MORNING.

KBDL TERMINAL...MODERATE CONFIDENCE IN TAF.

OUTLOOK...SUNDAY THROUGH TUESDAY...

SUNDAY...HIGH CONFIDENCE. MAINLY VFR ACROSS CENTRAL AND WESTERN
AREAS. E OF ORH MAY SEE MVFR CONDITIONS IN SNOW SHOWERS.

MONDAY-TUESDAY...MODERATE CONFIDENCE. MAINLY VFR. MAY SEE LOCAL
MVFR IN WIDELY SCT RAIN/SNOW SHOWERS MON NIGHT/TUE.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /TODAY THROUGH SATURDAY NIGHT/...HIGH CONFIDENCE.

HIGH PRESSURE BUILDING EAST N MAINE AND THE MARITIMES WILL KEEP
WINDS/SEAS BELOW SCA THRESHOLDS THROUGH SATURDAY NIGHT...WITH
WIND SPEEDS LESS THAN 20 KT. NORTHERLY WINDS TONIGHT BECOMING NE
SAT/SAT NIGHT. GUSTS UP TO 20 KT POSSIBLE SAT NIGHT ACROSS NE MA
COASTAL WATERS.

OUTLOOK...SUNDAY THROUGH TUESDAY...MODERATE TO HIGH CONFIDENCE.

SUNDAY THROUGH MONDAY...WINDS AND SEAS BELOW SMALL CRAFT
CRITERIA.

MONDAY NIGHT AND TUESDAY...EXPECT E-NE WINDS GUSTING UP TO 25 KT
WITH SEAS BUILDING UP TO 5-7 FT...HIGHEST ON THE EASTERN OUTER
WATERS FROM COASTAL LOW.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...KJC
NEAR TERM...KJC
SHORT TERM...KJC
LONG TERM...DUNTEN
AVIATION...KJC/DUNTEN
MARINE...KJC/DUNTEN





000
FXUS61 KBOX 192030
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
330 PM EST FRI DEC 19 2014

.SYNOPSIS...
A WEAK DISTURBANCE AND ONSHORE FLOW WILL RESULT IN A PERIOD OF
LIGHT SNOW/RAIN SHOWERS MAINLY ACROSS EASTERN NEW ENGLAND THIS
WEEKEND. LOW PRESSURE WILL PASS NEAR THE REGION ON
TUESDAY...BRINGING A PERIOD OF PRECIPITATION. A MUCH STRONGER
STORM IS LIKELY TO BRING HEAVY RAIN...WIND AND COASTAL FLOODING
CONCERNS TO SOUTHERN NEW ENGLAND WEDNESDAY INTO WEDNESDAY EVENING.
DRY BUT VERY WINDY CONDITIONS FOLLOW FOR CHRISTMAS DAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
PARTIAL CLEARING PUSHING SOUTH ACROSS NE MA THIS AFTERNOON AS LOW
LEVEL DRIER AIR MOVES IN FROM THE N. NAM IS HANDLING THIS LOW
LEVEL DRY AIR FAIRLY WELL AND SHOWS DRIER AIR OVERSPREADING MUCH
OF CENTRAL AND WESTERN ZONES TONIGHT WHICH SHOULD LEAD TO SOME
CLEARING. HOWEVER...LOW LEVEL MOISTURE WILL REMAIN LOCKED IN
ACROSS CAPE COD AND BACK IN ACROSS SE MA OVERNIGHT. IT LOOKS
MOSTLY DRY THROUGH THE NIGHT. MIN TEMPS MOSTLY IN THE 20S...WITH
LOWER 30S OUTER CAPE/ACK. TEMPS COULD DROP INTO THE TEENS N AND W
MA IF THERE IS SUFFICIENT CLEARING.

&&

.SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/...

HIGH PRES BUILDS ACROSS N MAINE AND THE MARITIMES WITH LOW LEVEL
FLOW VEERING TO THE E WHILE SFC WINDS MOSTLY NE. THIS WILL RESULT
IN LOW CLOUDS EXPANDING WEST ACROSS SNE DURING SAT AS LOW LEVEL
MOISTURE INCREASES. NOT REALLY LOOKING AT A PURE OCEAN EFFECT
SITUATION AS INSTABILITY IS MARGINAL. HOWEVER...HI-RES GUIDANCE
PICKING UP ON A DEVELOPING COASTAL FRONT ACROSS CAPE COD VICINITY
WITH E WINDS TO THE E OF THE BOUNDARY AND N/NE WINDS TO THE WEST.
LOW LEVEL FORCING COMBINED WITH DEEPENING MOISTURE AS MID LEVEL
SHORTWAVE MOVES IN FROM THE WEST WILL RESULT IN RAIN/SNOW SHOWERS
EXPANDING WEST FROM CAPE COD INTO EASTERN HALF NEW ENG. WHILE SOME
LIGHT PRECIP IS POSSIBLE IN THE MORNING...ESPECIALLY CAPE
COD...BULK OF PRECIP OCCURS LATER SAT INTO SAT NIGHT ASSOCD WITH
DEEPER MOISTURE AND LOW LEVEL LIFT FROM THE COASTAL FRONT/INVERTED
TROF.

PTYPE/SNOW ACCUM...
LOOKING AT MOSTLY RAIN FOR CAPE/ISLANDS AND POSSIBLY INTO SE
COASTAL PLYMOUTH COUNTY WHERE E WINDS WILL SUFFICIENTLY WARM THE
BOUNDARY LAYER KEEPING TEMPS IN THE MID/UPPER 30S. HOWEVER...JUST
INLAND AND NORTH FROM THE IMMEDIATE SE COAST AND WEST OF THE
COASTAL FRONT WHERE WINDS ARE FORECAST TO BE MORE
NORTHERLY...EXPECT MOSTLY SNOW ALTHOUGH THERE COULD BE A MIX AT
THE START. FREEZING DRIZZLE IS NOT LIKELY AS THE COLUMN MOISTENS
LATE SAT INTO SAT NIGHT WITH TEMPS -10C IN THE MOIST LAYER WHICH
IS COLD ENOUGH FOR ICE CRYSTAL PRODUCTION.

NAM IS PICKING UP ON SOME ENHANCEMENT IN N PLYMOUTH COUNTY INTO
NORFOLK COUNTY WITH QPF UP TO A THIRD OF AN INCH. THIS LIKELY
ASSOCD WITH A 20-25 KT E/NE LOW LEVEL JET THAT THE NAM IS
FORECASTING. HOWEVER...THIS MIGHT BE OVERDONE AS HI-RES WRF QPF
IS LESS AND OTHER MODELS ARE WEAKER WITH THE LOW LEVEL NE FLOW.
DONT WANT TO COMPLETELY IGNORE THE NAM AS IT SOMETIMES CAN PICK
UP ON HEAVIER MESOSCALE PRECIP IN THESE SITUATIONS SO USED A
BLEND OF NAM/GFS QPF TO TEMPER NAM OUTPUT. MAINLY LOOKING AT A
COATING TO AN INCH FOR EASTERN NEW ENG...HIGHEST AMOUNTS ACROSS E
MA AWAY FROM THE IMMEDIATE COAST. LOCALIZED AMOUNTS UP TO 2 INCHES
POSSIBLE...ESPECIALLY JUST SW OF BOSTON.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
HIGHLIGHTS...

* SCT SNOW/RAIN SHOWERS SUNDAY WITH AVG TEMPS
* WEAK WAVE OF LOW PRESSURE MON NIGHT/TUESDAY COULD BRING WINTRY
  MIX TO INTERIOR
* ANOMALOUS SYSTEM ACROSS THE GREAT LAKES WILL BRING HEAVY
  RAIN...GUSTY WINDS AND COASTAL CONCERNS AROUND CHRISTMAS EVE

OVERVIEW...

OVERALL 00Z GUIDANCE IS IN AGREEMENT SYNOPTICALLY WITH ISSUES ON
TIMING AND SMALLER SCALE FEATURES. AN AMPLIFIED MID-UPPER LEVEL
TROUGH AND PCPN FOCUSING LEAD SURFACE LOW/FRONTAL SYSTEM DEVELOPS
OVER THE CENTRAL US BY EARLY NEXT WEEK. THE SUPPORTING AND
INCREASINGLY NEG-TILT TROUGH ALOFT WORKS OVER THE ERN US AND OUT
THROUGH THE NERN STATES INTO DAYS 5/6 WED/THU.  MODELS/ENSEMBLES
HAVE BEEN FAIRLY CONSISTENT IN RECENT RUNS ON THIS AMPLIFIED PATTERN
AND THE MOST RECENT GEFS/ECMWF ENSEMBLE GUIDANCE SHOW GOOD
CORRELATION TO NEXT THURSDAY.

DURING THIS SYNOPTIC TRANSITION...HIGH PRESSURE AND UPPER LEVEL
RIDGE WILL BE OVER THE NORTHEAST SATURDAY NIGHT BEFORE DEPARTING
LATE SUNDAY. LONGWAVE DIGGING TROUGH OVER THE CENTRAL CONUS WILL
PUSH A FEW SHORTWAVES THROUGH THE FLOW. FIRST ONE DEVELOPS A WEAK
COASTAL LOW MOVING TOWARDS THE REGION LATE MONDAY INTO TUESDAY.
THERE IS STILL SOME UNCERTAINTY WITH THE LOCATION OF THIS SYSTEM
BUT APPEARS THAT THERE WILL BE SNOW/WINTRY MIX IN THE INTERIOR. AS
THIS SYSTEM DEPARTS APPEARS AN ANOMALOUS LOW OVER THE GREAT LAKES
WILL DEVELOP A SECONDARY LOW /DOUBLE BARREL LOW/ CLOSER TO NEW
ENGLAND...PER ENSEMBLE GUIDANCE. STILL A GOOD AMOUNT OF SPREAD BUT
IF THIS DOUBLE LOW DOES DEVELOP THEN THE RAIN AND WIND ASPECT OF THE
SYSTEM INCREASES...DETAILS BELOW. STILL SOME UNCERTAINTY WITH THIS
PARTICULAR SYSTEM BUT WITH 2 TO 3 SD AWAY AND GENERAL MODEL
AGREEMENT HAVE HIGHER CONFIDENCE THIS SYSTEM WILL IMPACT SOUTHERN
NEW ENGLAND.

DETAILS...

MONDAY INTO TUESDAY...MODERATE CONFIDENCE.

WEAK COASTAL LOW PRESSURE SYSTEM WILL DEVELOP AND MOVE CLOSE TO THE
SOUTHERN NEW ENGLAND COASTLINE. THERE IS STILL DESCENT MODEL SPREAD
ON THE EXACT LOW TRACK BUT APPEARS THAT IT DOES WEAKEN AS IT
APPROACHES FROM THE MID-ATLANTIC. REGARDLESS THERE COULD ALLOW FOR
SHALLOW COLD AIR FROM THE DEPARTING TO HIGH TO STAY TRAP AND WITH
WARM AIR ALOFT MOVING INTO THE REGION...COULD SEE SNOW OR WINTRY
PRECIP ESP ACROSS THE HIGHER TERRAIN LATE MONDAY INTO TUESDAY
MORNING. BECAUSE OF THE MODEL SPREAD STILL HAVE DETAILS TO WORK OUT
BUT SOMETHING TO WATCH CLOSELY.

TEMPERATURES WILL SLOWLY BEGIN TO WARM ON TUESDAY AS SOUTHERLY FLOW
BECOMES DOMINATE OUT AHEAD OF STRONGER SYSTEM TO THE EAST. EASTERLY
FLOW WILL CONTINUE TO DOMINATE AT THE SURFACE WITH A EASTERLY LLJ
STRENGTHEN ABOUT 20-30KTS. TUESDAYS HIGH TIDE AT BOSTON WILL BE 11.6
DURING THE LATE MORNING...AND WITH PERSISTENT EASTERLY WINDS
ANTICIPATE AT LEAST MINOR COASTAL FLOODING. IF THIS SURFACE LOW
STRENGTHENS AND THE EASTERLY FLOW INCREASES THEN THE MASS EAST
COASTLINE WILL HAVE TO BE WATCHED CLOSELY DURING THE TUESDAY HIGH
TIDE.

WEDNESDAY INTO THURSDAY...HIGH CONFIDENCE IN SYSTEM LOW CONFIDENCE
ON DETAILS.

STRONG ANOMALOUS SYSTEM WILL STRENGTHEN OVER THE GREAT
LAKES...DEVELOPING A POTENTIAL SECONDARY SURFACE LOW JUST WEST OF
SOUTHERN NEW ENGLAND. STILL A LOT OF DETAILS TO WORK OUT AS THIS
SYSTEM IS STILL 5+ DAYS AWAY...HOWEVER ENSEMBLES SHOW THAT THIS
SYSTEM IS AROUND 2 TO 3 STANDARD DEVIATIONS ALLOWING FOR INCREASING
CONFIDENCE THAT A POTENT STORM WILL OCCUR. LATEST 00Z GUIDANCE SHOWS
THAT MOST PRECIP WILL BE LIQUID WITH A DEEP SUBTROPICAL CONNECTION
BACK ACROSS MEXICO... PW ANOMALIES FORECAST TO RISE TO BETWEEN +1 TO
+3 /OR HIGHER/...AND TEMPERATURES WELL ABOVE AVERAGE. IN FACT WE MAY
BE CLOSE AT BREAKING RECORD HIGH TEMPS IF TEMPS WARM TO 60F OR ABOVE
ON CHRISTMAS EVE.  AS THE SYSTEM WRAPS UP INTO CANADA...COLD AIR
ADVECTION SHOULD CIRCULATE AROUND AND BEGIN A TRANSITION FROM
SOUTHWEST TO NORTHEAST IN TURNING P-TYPE TO SNOW. HOWEVER LATEST
GUIDANCE DOES SHOW A QUICK MOVING DRY SLOT SO SNOWFALL WILL STRUGGLE
DUE TO LACK OF MOISTURE.

THIS SYSTEM IS QUITE POTENT SO WE WILL NEED TO WATCH FOR POTENTIAL
HAZARDS. CURRENTLY THINK THAT WE COULD SEE POSSIBLE URBAN FLOODING
ISSUES AS WELL AS WIND ISSUES. GUIDANCE RIGHT NOW IS SHOWING A 45 TO
55 KT JET AT 925 MB WHICH MAY WARRANT WIND ADVISORIES BUT THIS
SYSTEM COULD STRENGTHEN EVEN MORE SO A STRONGER JET IS POSSIBLE.

LASTLY COASTAL FLOODING ISSUES WILL NEED TO BE ADDRESS AS HIGH TIDE
ON WED AND THUS ARE 11.7 AND 11.5 RESPECTIVELY FOR BOSTON. ANY
EASTERLY COMPONENT WILL PUSH THE TIDE ABOVE FLOOD SO COASTAL
FLOODING IS POSSIBLE AS WELL AS BEACH EROSION. THE SOUTH COASTLINE
WILL ALSO HAVE TO BE WATCH CLOSELY. A VERY STRONG SOUTHERLY JET
WILL DEVELOP WED INTO THURSDAY AND WITH ASTRONOMICAL HIGH TIDE
COULD ALSO SEE MINOR TO MODERATE COASTAL FLOODING. ANOTHER ISSUE
IS THE POTENTIAL PRESSURE FALLS IF THIS SYSTEM STRENGTHENS EVEN
MORE...IT COULD ADD ANOTHER FOOT ONTO THE SURGE.

FRIDAY...LOW CONFIDENCE.

ONCE UPPER LOW MOVES INTO SOUTHERN CANADA...EXPECT A RATHER FAST
UPPER W FLOW IN PLACE. MAY SEE LEFTOVER SNOW SHOWERS BUT TEMPS WILL
FALL BACK CLOSE TO SEASONAL NORMS.

&&

.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /TODAY THROUGH SATURDAY/...

THROUGH 00Z...LOW VFR AND MVFR CIGS WILL PERSIST...BUT BECOMING
VFR ALONG THE E MA COAST AS CLEARING MOVES IN FROM THE N.

TONIGHT...MODERATE CONFIDENCE. EXPECT PARTIAL CLEARING AND
BECOMING VFR DURING THE NIGHT AS LOW LEVEL DRY AIR MOVES SOUTH
ACROSS THE REGION. HOWEVER...LOW CLOUDS AND MVFR CIGS OVER THE
OUTER CAPE WILL GRADUALLY BACK IN ACROSS SE MA OVERNIGHT.

SATURDAY...MODERATE CONFIDENCE. MVFR CIGS ACROSS SE NEW ENG WILL
EXPAND WEST ACROSS THE REST OF THE COASTAL PLAIN THEN INTO THE
INTERIOR DURING THE AFTERNOON. CT VALLEY SHOULD REMAIN VFR.
SCATTERED RAIN SHOWERS WILL DEVELOP OVER CAPE COD WITH SNOW
SHOWERS INTO E MA BY LATE AFTERNOON.

SATURDAY NIGHT...MODERATE CONFIDENCE. WIDESPREAD MVFR CIGS WITH
POCKETS OF IFR E MA COAST. PERIODS OF LIGHT RAIN OVER CAPE COD
WITH LIGHT SNOW FURTHER INLAND ACROSS E MA. MINOR ACCUM POSSIBLE
ACROSS E MA JUST INLAND FROM THE IMMEDIATE COAST.

KBOS TERMINAL...MODERATE CONFIDENCE IN TAF. EXPECT VFR
TONIGHT...BEFORE MVFR CIGS DEVELOP SAT MORNING.

KBDL TERMINAL...MODERATE CONFIDENCE IN TAF.

OUTLOOK...SUNDAY THROUGH TUESDAY...

SUNDAY...HIGH CONFIDENCE. MAINLY VFR ACROSS CENTRAL AND WESTERN
AREAS. E OF ORH MAY SEE MVFR CONDITIONS IN SNOW SHOWERS.

MONDAY-TUESDAY...MODERATE CONFIDENCE. MAINLY VFR. MAY SEE LOCAL
MVFR IN WIDELY SCT RAIN/SNOW SHOWERS MON NIGHT/TUE.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /TODAY THROUGH SATURDAY NIGHT/...HIGH CONFIDENCE.

HIGH PRESSURE BUILDING EAST N MAINE AND THE MARITIMES WILL KEEP
WINDS/SEAS BELOW SCA THRESHOLDS THROUGH SATURDAY NIGHT...WITH
WIND SPEEDS LESS THAN 20 KT. NORTHERLY WINDS TONIGHT BECOMING NE
SAT/SAT NIGHT. GUSTS UP TO 20 KT POSSIBLE SAT NIGHT ACROSS NE MA
COASTAL WATERS.

OUTLOOK...SUNDAY THROUGH TUESDAY...MODERATE TO HIGH CONFIDENCE.

SUNDAY THROUGH MONDAY...WINDS AND SEAS BELOW SMALL CRAFT
CRITERIA.

MONDAY NIGHT AND TUESDAY...EXPECT E-NE WINDS GUSTING UP TO 25 KT
WITH SEAS BUILDING UP TO 5-7 FT...HIGHEST ON THE EASTERN OUTER
WATERS FROM COASTAL LOW.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...KJC
NEAR TERM...KJC
SHORT TERM...KJC
LONG TERM...DUNTEN
AVIATION...KJC/DUNTEN
MARINE...KJC/DUNTEN




000
FXUS61 KBOX 191755
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
1255 PM EST FRI DEC 19 2014

.SYNOPSIS...
HIGH PRESSURE MOVING INTO EASTERN CANADA WILL RESULT IN DRY BUT
CHILLY WEATHER TODAY.  A WEAK DISTURBANCE AND ONSHORE FLOW WILL
RESULT IN A PERIOD OF SOME LIGHT RAIN/SNOW SHOWERS MAINLY ACROSS
EASTERN NEW THIS WEEKEND. LOW PRESSURE WILL PASS NEAR THE REGION
ON TUESDAY...BRINGING A PERIOD OF PRECIPITATION. A MUCH STRONGER
STORM IS LIKELY TO BRING HEAVY RAIN...WIND AND COASTAL FLOODING
CONCERNS TO SOUTHERN NEW ENGLAND WEDNESDAY INTO WEDNESDAY
EVENING. DRY BUT VERY WINDY CONDITIONS FOLLOW FOR CHRISTMAS DAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
1250 PM UPDATE...
CLEARING TO THE N SLOWLY MOVING SOUTH INTO ESSEX COUNTY AND
EXPECT SOME SUNSHINE THIS AFTERNOON ACROSS NE MA. ELSEWHERE...
CLOUDS WILL REMAIN TRAPPED BELOW THE INVERSION. FORECAST ON
TRACK.

PREVIOUS DISCUSSION...
12Z SOUNDINGS SHOW A SHALLOW LAYER OF LOW LEVEL MOISTURE TRAPPED
BELOW A STRONG SUBSIDENCE INVERSION. NAM SOUNDINGS SHOW THIS
MOISTURE REMAINING IN PLACE SO THESE LOW CLOUDS WILL LIKELY HANG
TOUGH MOST OF THE DAY RESULTING IN MOSTLY CLOUDY SKIES.
HOWEVER...NOTING A LARGE CLEAR AREA ACROSS SW MAINE AND EASTERN
NH. NAM IS INDICATING A LOW LEVEL DRY SLOT EXPANDING SOUTH INTO E
MA LATER THIS AFTERNOON SO BEST CHANCE FOR PTSUNNY SKIES WILL BE
ACROSS NE MA. ADJUSTED SKY GRIDS TO REFLECT MORE CLOUDS AND
POTENTIAL FOR SOME SUNSHINE ACROSS NE MA.

NO CHANGES TO TEMPS. CLOUD COVER WILL LIMIT TEMP RISE WITH MOST
LOCATIONS REMAINING IN THE MID/UPPER 30S...BUT CLOSER TO 30 ACROSS
THE HIGH TERRAIN IN WESTERN AND N MA.

&&

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

HIGH PRESSURE ACROSS EASTERN CANADA GRADUALLY SLIDES EAST.  THIS
WILL ALLOW SURFACE WINDS TO TURN TO A MORE NORTHERLY DIRECTION.  IN
RESPONSE...OCEAN EFFECT CLOUDS WILL MOVE ONTO EASTERN NEW ENGLAND
COAST. DELTA T VALUES FROM THE OCEAN TO THE MIXED LAYER IS AROUND
13C...SO MAY SEE SOME LIGHT SNOW SHOWERS/FLURRIES DEVELOP ACROSS THE
CAPE/ISLANDS AND PLYMOUTH COUNTY BY DAYBREAK SAT.  LOW TEMPS WILL
MAINLY BE IN THE 20S...BUT LOWER TO MIDDLE 30S ON THE IMMEDIATE
SOUTHEAST NEW ENGLAND COAST.

SATURDAY...

INTERESTING SETUP.  WEAK INVERTED TROUGH DEVELOPS ACROSS THE REGION.
NORTHEAST SURFACE WINDS COMBINED WITH WINDS JUST OFF THE DECK
TURNING EAST SOUTHEAST WILL MOISTEN UP THE ATMOSPHERE ACROSS THE
SOUTHEAST NEW ENGLAND COAST.  850 TEMPS AROUND -6C SHOULD BE COLD
ENOUGH FOR ICE NUCLEATION...ESPECIALLY GIVEN EASTERLY FLOW BRINGING
SALT PARTICLES IN OFF THE OCEAN.  THEREFORE...NOT TOO CONCERNED
ABOUT FREEZING DRIZZLE AT THIS TIME BUT THINK WILL BE DEALING WITH
SNOW SHOWERS.

LIGHT SNOW SHOWERS SHOULD AFFECT FAR SOUTHEAST MA...ESPECIALLY
PLYMOUTH COUNTY WHERE PATTERN RECOGNITION WARRANTS LIKELY POPS.  AS
THE AFTERNOON WEARS ON WE MAY SEE THESE LIGHT SNOW SHOWERS DEVELOP
ACROSS CAPE ANN AND PERHAPS EVEN FURTHER INTO EASTERN MA BY EARLY
EVENING.  ENOUGH MILD AIR SHOULD COME IN OFF THE OCEAN TO RESULT IN
PTYPE CHANGING TO LIGHT RAIN SHOWERS ACROSS PORTIONS OF THE
CAPE/ISLANDS AND PERHAPS ONTO PORTIONS OF THE IMMEDIATE SOUTHEAST
PLYMOUTH COUNTY COAST.

AS FOR SNOW ACCUMULATIONS...MAINLY JUST LOOKING AT A COATING TO LESS
THAN 1 INCH ACROSS SOUTHEAST NEW ENGLAND THROUGH EARLY SATURDAY
EVENING.  HOWEVER...LOW RISK FOR VERY LOCALIZED 1 TO 2 INCH SNOW
AMOUNTS ACROSS PORTIONS OF PLYMOUTH COUNTY IF THE BOUNDARY LAYER
REMAINS COLD ENOUGH FOR SNOW.

&&

.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
HIGHLIGHTS...

* SCT SNOW/RAIN SHOWERS SUNDAY WITH AVG TEMPS
* WEAK WAVE OF LOW PRESSURE MON NIGHT/TUESDAY COULD BRING WINTRY
  MIX TO INTERIOR
* ANOMALOUS SYSTEM ACROSS THE GREAT LAKES WILL BRING HEAVY
  RAIN...GUSTY WINDS AND COASTAL CONCERNS AROUND CHRISTMAS EVE

OVERVIEW...

OVERALL 00Z GUIDANCE IS IN AGREEMENT SYNOPTICALLY WITH ISSUES ON
TIMING AND SMALLER SCALE FEATURES. AN AMPLIFIED MID-UPPER LEVEL
TROUGH AND PCPN FOCUSING LEAD SURFACE LOW/FRONTAL SYSTEM DEVELOPS
OVER THE CENTRAL US BY EARLY NEXT WEEK. THE SUPPORTING AND
INCREASINGLY NEG-TILT TROUGH ALOFT WORKS OVER THE ERN US AND OUT
THROUGH THE NERN STATES INTO DAYS 5/6 WED/THU.  MODELS/ENSEMBLES
HAVE BEEN FAIRLY CONSISTENT IN RECENT RUNS ON THIS AMPLIFIED PATTERN
AND THE MOST RECENT GEFS/ECMWF ENSEMBLE GUIDANCE SHOW GOOD
CORRELATION TO NEXT THURSDAY.

DURING THIS SYNOPTIC TRANSITION...HIGH PRESSURE AND UPPER LEVEL
RIDGE WILL BE OVER THE NORTHEAST SATURDAY NIGHT BEFORE DEPARTING
LATE SUNDAY. LONGWAVE DIGGING TROUGH OVER THE CENTRAL CONUS WILL
PUSH A FEW SHORTWAVES THROUGH THE FLOW. FIRST ONE DEVELOPS A WEAK
COASTAL LOW MOVING TOWARDS THE REGION LATE MONDAY INTO TUESDAY.
THERE IS STILL SOME UNCERTAINTY WITH THE LOCATION OF THIS SYSTEM
BUT APPEARS THAT THERE WILL BE SNOW/WINTRY MIX IN THE INTERIOR. AS
THIS SYSTEM DEPARTS APPEARS AN ANOMALOUS LOW OVER THE GREAT LAKES
WILL DEVELOP A SECONDARY LOW /DOUBLE BARREL LOW/ CLOSER TO NEW
ENGLAND...PER ENSEMBLE GUIDANCE. STILL A GOOD AMOUNT OF SPREAD BUT
IF THIS DOUBLE LOW DOES DEVELOP THEN THE RAIN AND WIND ASPECT OF THE
SYSTEM INCREASES...DETAILS BELOW. STILL SOME UNCERTAINTY WITH THIS
PARTICULAR SYSTEM BUT WITH 2 TO 3 SD AWAY AND GENERAL MODEL
AGREEMENT HAVE HIGHER CONFIDENCE THIS SYSTEM WILL IMPACT SOUTHERN
NEW ENGLAND.

DETAILS...

SATURDAY NIGHT INTO SUNDAY...HIGH CONFIDENCE.

WEAK WAVE WILL MOVE THROUGH THE FLOW ON SATURDAY NIGHT AND WITH HIGH
PRESSURE SHIFTING EASTWARD EXPECT ONSHORE EASTERLY FLOW. GUIDANCE
CONTINUES TO SHOW QPF MOVING ONSHORE AND WITH MOISTURE AND THE LIFT
COULD SEE SNOW SHOWERS MOVING INLAND SATURDAY NIGHT INTO SUNDAY.
BIGGEST QUESTION IS WILL THE MOISTURE SATURATE ENOUGH TO -6C. IF NOT
THEN THE POTENTIAL FOR FREEZING DRIZZLE IS POSSIBLE. BELIEVE THAT
WITH A SOUTHERLY FLOW AT 850MB AND EASTERLY FLOW AT THE SURFACE WILL
ALLOW FOR THE PROFILE TO SATURATE. USUALLY YOU WOULD WANT SATURATION
UP TO -8C BUT BECAUSE OF SALT NUCLEI THE SNOW GROWTH REGION BEGINS
AT -5C OR -6C. APPEARS THAT THERE IS ENOUGH MOISTURE SO A QUICK HALF
INCH TO AN INCH IS POSSIBLE PER SOUNDINGS EAST OF THE WORCESTER
HILLS. HOWEVER BECAUSE IT IS A MORE ENE FLOW...PLYMOUTH COUNTY MAY
SEE 1 TO 2 INCHES IF THEY REMAIN COLD ENOUGH FOR SNOW...ESP DURING
THE DAY ON SUNDAY.

SNOW MAY OVERSPREAD ACROSS THE WEST DURING THE DAY IF THERE IS
ENOUGH MOISTURE. HOWEVER RIDGE BEGINS TO BUILD INTO THE REGION LATE
SUNDAY INTO SUNDAY NIGHT SO THE POTENTIAL FOR SNOW SHOWERS WILL BE
LIMITED DUE TO PRESSURE RISE.

MONDAY INTO TUESDAY...MODERATE CONFIDENCE.

WEAK COASTAL LOW PRESSURE SYSTEM WILL DEVELOP AND MOVE CLOSE TO THE
SOUTHERN NEW ENGLAND COASTLINE. THERE IS STILL DESCENT MODEL SPREAD
ON THE EXACT LOW TRACK BUT APPEARS THAT IT DOES WEAKEN AS IT
APPROACHES FROM THE MID-ATLANTIC. REGARDLESS THERE COULD ALLOW FOR
SHALLOW COLD AIR FROM THE DEPARTING TO HIGH TO STAY TRAP AND WITH
WARM AIR ALOFT MOVING INTO THE REGION...COULD SEE SNOW OR WINTRY
PRECIP ESP ACROSS THE HIGHER TERRAIN LATE MONDAY INTO TUESDAY
MORNING. BECAUSE OF THE MODEL SPREAD STILL HAVE DETAILS TO WORK OUT
BUT SOMETHING TO WATCH CLOSELY.

TEMPERATURES WILL SLOWLY BEGIN TO WARM ON TUESDAY AS SOUTHERLY FLOW
BECOMES DOMINATE OUT AHEAD OF STRONGER SYSTEM TO THE EAST. EASTERLY
FLOW WILL CONTINUE TO DOMINATE AT THE SURFACE WITH A EASTERLY LLJ
STRENGTHEN ABOUT 20-30KTS. TUESDAYS HIGH TIDE AT BOSTON WILL BE 11.6
DURING THE LATE MORNING...AND WITH PERSISTENT EASTERLY WINDS
ANTICIPATE AT LEAST MINOR COASTAL FLOODING. IF THIS SURFACE LOW
STRENGTHENS AND THE EASTERLY FLOW INCREASES THEN THE MASS EAST
COASTLINE WILL HAVE TO BE WATCHED CLOSELY DURING THE TUESDAY HIGH
TIDE.

WEDNESDAY INTO THURSDAY...HIGH CONFIDENCE IN SYSTEM LOW CONFIDENCE
ON DETAILS.

STRONG ANOMALOUS SYSTEM WILL STRENGTHEN OVER THE GREAT
LAKES...DEVELOPING A POTENTIAL SECONDARY SURFACE LOW JUST WEST OF
SOUTHERN NEW ENGLAND. STILL A LOT OF DETAILS TO WORK OUT AS THIS
SYSTEM IS STILL 5+ DAYS AWAY...HOWEVER ENSEMBLES SHOW THAT THIS
SYSTEM IS AROUND 2 TO 3 STANDARD DEVIATIONS ALLOWING FOR INCREASING
CONFIDENCE THAT A POTENT STORM WILL OCCUR. LATEST 00Z GUIDANCE SHOWS
THAT MOST PRECIP WILL BE LIQUID WITH A DEEP SUBTROPICAL CONNECTION
BACK ACROSS MEXICO... PW ANOMALIES FORECAST TO RISE TO BETWEEN +1 TO
+3 /OR HIGHER/...AND TEMPERATURES WELL ABOVE AVERAGE. IN FACT WE MAY
BE CLOSE AT BREAKING RECORD HIGH TEMPS IF TEMPS WARM TO 60F OR ABOVE
ON CHRISTMAS EVE.  AS THE SYSTEM WRAPS UP INTO CANADA...COLD AIR
ADVECTION SHOULD CIRCULATE AROUND AND BEGIN A TRANSITION FROM
SOUTHWEST TO NORTHEAST IN TURNING P-TYPE TO SNOW. HOWEVER LATEST
GUIDANCE DOES SHOW A QUICK MOVING DRY SLOT SO SNOWFALL WILL STRUGGLE
DUE TO LACK OF MOISTURE.

THIS SYSTEM IS QUITE POTENT SO WE WILL NEED TO WATCH FOR POTENTIAL
HAZARDS. CURRENTLY THINK THAT WE COULD SEE POSSIBLE URBAN FLOODING
ISSUES AS WELL AS WIND ISSUES. GUIDANCE RIGHT NOW IS SHOWING A 45 TO
55 KT JET AT 925 MB WHICH MAY WARRANT WIND ADVISORIES BUT THIS
SYSTEM COULD STRENGTHEN EVEN MORE SO A STRONGER JET IS POSSIBLE.

LASTLY COASTAL FLOODING ISSUES WILL NEED TO BE ADDRESS AS HIGH TIDE
ON WED AND THUS ARE 11.7 AND 11.5 RESPECTIVELY FOR BOSTON. ANY
EASTERLY COMPONENT WILL PUSH THE TIDE ABOVE FLOOD SO COASTAL
FLOODING IS POSSIBLE AS WELL AS BEACH EROSION. THE SOUTH COASTLINE
WILL ALSO HAVE TO BE WATCH CLOSELY. A VERY STRONG SOUTHERLY JET
WILL DEVELOP WED INTO THURSDAY AND WITH ASTRONOMICAL HIGH TIDE
COULD ALSO SEE MINOR TO MODERATE COASTAL FLOODING. ANOTHER ISSUE
IS THE POTENTIAL PRESSURE FALLS IF THIS SYSTEM STRENGTHENS EVEN
MORE...IT COULD ADD ANOTHER FOOT ONTO THE SURGE.

FRIDAY...LOW CONFIDENCE.

ONCE UPPER LOW MOVES INTO SOUTHERN CANADA...EXPECT A RATHER FAST
UPPER W FLOW IN PLACE. MAY SEE LEFTOVER SNOW SHOWERS BUT TEMPS WILL
FALL BACK CLOSE TO SEASONAL NORMS.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /TODAY THROUGH SATURDAY/...

THROUGH 00Z...LOW VFR AND MVFR CIGS WILL PERSIST...BUT BECOMING
VFR ALONG THE E MA COAST AS CLEARING MOVES IN FROM THE N.

TONIGHT...MODERATE CONFIDENCE. EXPECT PARTIAL CLEARING AND
BECOMING VFR DURING THE NIGHT AS LOW LEVEL DRY AIR MOVES SOUTH
ACROSS THE REGION. HOWEVER...LOW CLOUDS AND MVFR CIGS OVER THE
OUTER CAPE WILL GRADUALLY BACK IN ACROSS SE MA OVERNIGHT.

SATURDAY...MODERATE CONFIDENCE. MVFR CIGS ACROSS SE NEW ENG WILL
EXPAND WEST ACROSS THE REST OF THE COASTAL PLAIN THEN INTO THE
INTERIOR DURING THE AFTERNOON. CT VALLEY SHOULD REMAIN VFR.
SCATTERED RAIN SHOWERS WILL DEVELOP OVER CAPE COD WITH SNOW
SHOWERS INTO E MA BY LATE AFTERNOON.

SATURDAY NIGHT...MODERATE CONFIDENCE. WIDESPREAD MVFR CIGS WITH
POCKETS OF IFR E MA COAST. PERIODS OF LIGHT RAIN OVER CAPE COD
WITH LIGHT SNOW FURTHER INLAND ACROSS E MA. MINOR ACCUM POSSIBLE
ACROSS E MA JUST INLAND FROM THE IMMEDIATE COAST.

KBOS TERMINAL...MODERATE CONFIDENCE IN TAF. EXPECT VFR
TONIGHT...BEFORE MVFR CIGS DEVELOP SAT MORNING.

KBDL TERMINAL...MODERATE CONFIDENCE IN TAF.

OUTLOOK...SUNDAY THROUGH TUESDAY...

SUNDAY...HIGH CONFIDENCE. MAINLY VFR ACROSS CENTRAL AND WESTERN
AREAS. E OF ORH MAY SEE MVFR CONDITIONS IN SNOW SHOWERS.

MONDAY-TUESDAY...MODERATE CONFIDENCE. MAINLY VFR. MAY SEE LOCAL
MVFR IN WIDELY SCT RAIN/SNOW SHOWERS MON NIGHT/TUE.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /TODAY THROUGH SATURDAY/...HIGH CONFIDENCE.

HIGH PRESSURE BUILDING EAST INTO QUEBEC AND NORTHERN NEW ENGLAND
WILL KEEP WINDS/SEAS BELOW SCA THRESHOLDS THROUGH SATURDAY.
NORTHWEST WINDS TODAY WILL TURN NORTHEAST BY SATURDAY WITH GUSTS
BETWEEN 15 AND 20 KNOTS POSSIBLE AT TIMES.

OUTLOOK...SATURDAY THROUGH TUESDAY...MODERATE TO HIGH CONFIDENCE.

SATURDAY THROUGH MONDAY...WINDS AND SEAS BELOW SMALL CRAFT
CRITERIA.

MONDAY NIGHT AND TUESDAY...EXPECT E-NE WINDS GUSTING UP TO 25 KT
WITH SEAS BUILDING UP TO 5-7 FT...HIGHEST ON THE EASTERN OUTER
WATERS FROM COASTAL LOW.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...FRANK/DUNTEN
NEAR TERM...KJC
SHORT TERM...FRANK
LONG TERM...DUNTEN
AVIATION...KJC/DUNTEN
MARINE...FRANK/DUNTEN




000
FXUS61 KBOX 191755
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
1255 PM EST FRI DEC 19 2014

.SYNOPSIS...
HIGH PRESSURE MOVING INTO EASTERN CANADA WILL RESULT IN DRY BUT
CHILLY WEATHER TODAY.  A WEAK DISTURBANCE AND ONSHORE FLOW WILL
RESULT IN A PERIOD OF SOME LIGHT RAIN/SNOW SHOWERS MAINLY ACROSS
EASTERN NEW THIS WEEKEND. LOW PRESSURE WILL PASS NEAR THE REGION
ON TUESDAY...BRINGING A PERIOD OF PRECIPITATION. A MUCH STRONGER
STORM IS LIKELY TO BRING HEAVY RAIN...WIND AND COASTAL FLOODING
CONCERNS TO SOUTHERN NEW ENGLAND WEDNESDAY INTO WEDNESDAY
EVENING. DRY BUT VERY WINDY CONDITIONS FOLLOW FOR CHRISTMAS DAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
1250 PM UPDATE...
CLEARING TO THE N SLOWLY MOVING SOUTH INTO ESSEX COUNTY AND
EXPECT SOME SUNSHINE THIS AFTERNOON ACROSS NE MA. ELSEWHERE...
CLOUDS WILL REMAIN TRAPPED BELOW THE INVERSION. FORECAST ON
TRACK.

PREVIOUS DISCUSSION...
12Z SOUNDINGS SHOW A SHALLOW LAYER OF LOW LEVEL MOISTURE TRAPPED
BELOW A STRONG SUBSIDENCE INVERSION. NAM SOUNDINGS SHOW THIS
MOISTURE REMAINING IN PLACE SO THESE LOW CLOUDS WILL LIKELY HANG
TOUGH MOST OF THE DAY RESULTING IN MOSTLY CLOUDY SKIES.
HOWEVER...NOTING A LARGE CLEAR AREA ACROSS SW MAINE AND EASTERN
NH. NAM IS INDICATING A LOW LEVEL DRY SLOT EXPANDING SOUTH INTO E
MA LATER THIS AFTERNOON SO BEST CHANCE FOR PTSUNNY SKIES WILL BE
ACROSS NE MA. ADJUSTED SKY GRIDS TO REFLECT MORE CLOUDS AND
POTENTIAL FOR SOME SUNSHINE ACROSS NE MA.

NO CHANGES TO TEMPS. CLOUD COVER WILL LIMIT TEMP RISE WITH MOST
LOCATIONS REMAINING IN THE MID/UPPER 30S...BUT CLOSER TO 30 ACROSS
THE HIGH TERRAIN IN WESTERN AND N MA.

&&

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

HIGH PRESSURE ACROSS EASTERN CANADA GRADUALLY SLIDES EAST.  THIS
WILL ALLOW SURFACE WINDS TO TURN TO A MORE NORTHERLY DIRECTION.  IN
RESPONSE...OCEAN EFFECT CLOUDS WILL MOVE ONTO EASTERN NEW ENGLAND
COAST. DELTA T VALUES FROM THE OCEAN TO THE MIXED LAYER IS AROUND
13C...SO MAY SEE SOME LIGHT SNOW SHOWERS/FLURRIES DEVELOP ACROSS THE
CAPE/ISLANDS AND PLYMOUTH COUNTY BY DAYBREAK SAT.  LOW TEMPS WILL
MAINLY BE IN THE 20S...BUT LOWER TO MIDDLE 30S ON THE IMMEDIATE
SOUTHEAST NEW ENGLAND COAST.

SATURDAY...

INTERESTING SETUP.  WEAK INVERTED TROUGH DEVELOPS ACROSS THE REGION.
NORTHEAST SURFACE WINDS COMBINED WITH WINDS JUST OFF THE DECK
TURNING EAST SOUTHEAST WILL MOISTEN UP THE ATMOSPHERE ACROSS THE
SOUTHEAST NEW ENGLAND COAST.  850 TEMPS AROUND -6C SHOULD BE COLD
ENOUGH FOR ICE NUCLEATION...ESPECIALLY GIVEN EASTERLY FLOW BRINGING
SALT PARTICLES IN OFF THE OCEAN.  THEREFORE...NOT TOO CONCERNED
ABOUT FREEZING DRIZZLE AT THIS TIME BUT THINK WILL BE DEALING WITH
SNOW SHOWERS.

LIGHT SNOW SHOWERS SHOULD AFFECT FAR SOUTHEAST MA...ESPECIALLY
PLYMOUTH COUNTY WHERE PATTERN RECOGNITION WARRANTS LIKELY POPS.  AS
THE AFTERNOON WEARS ON WE MAY SEE THESE LIGHT SNOW SHOWERS DEVELOP
ACROSS CAPE ANN AND PERHAPS EVEN FURTHER INTO EASTERN MA BY EARLY
EVENING.  ENOUGH MILD AIR SHOULD COME IN OFF THE OCEAN TO RESULT IN
PTYPE CHANGING TO LIGHT RAIN SHOWERS ACROSS PORTIONS OF THE
CAPE/ISLANDS AND PERHAPS ONTO PORTIONS OF THE IMMEDIATE SOUTHEAST
PLYMOUTH COUNTY COAST.

AS FOR SNOW ACCUMULATIONS...MAINLY JUST LOOKING AT A COATING TO LESS
THAN 1 INCH ACROSS SOUTHEAST NEW ENGLAND THROUGH EARLY SATURDAY
EVENING.  HOWEVER...LOW RISK FOR VERY LOCALIZED 1 TO 2 INCH SNOW
AMOUNTS ACROSS PORTIONS OF PLYMOUTH COUNTY IF THE BOUNDARY LAYER
REMAINS COLD ENOUGH FOR SNOW.

&&

.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
HIGHLIGHTS...

* SCT SNOW/RAIN SHOWERS SUNDAY WITH AVG TEMPS
* WEAK WAVE OF LOW PRESSURE MON NIGHT/TUESDAY COULD BRING WINTRY
  MIX TO INTERIOR
* ANOMALOUS SYSTEM ACROSS THE GREAT LAKES WILL BRING HEAVY
  RAIN...GUSTY WINDS AND COASTAL CONCERNS AROUND CHRISTMAS EVE

OVERVIEW...

OVERALL 00Z GUIDANCE IS IN AGREEMENT SYNOPTICALLY WITH ISSUES ON
TIMING AND SMALLER SCALE FEATURES. AN AMPLIFIED MID-UPPER LEVEL
TROUGH AND PCPN FOCUSING LEAD SURFACE LOW/FRONTAL SYSTEM DEVELOPS
OVER THE CENTRAL US BY EARLY NEXT WEEK. THE SUPPORTING AND
INCREASINGLY NEG-TILT TROUGH ALOFT WORKS OVER THE ERN US AND OUT
THROUGH THE NERN STATES INTO DAYS 5/6 WED/THU.  MODELS/ENSEMBLES
HAVE BEEN FAIRLY CONSISTENT IN RECENT RUNS ON THIS AMPLIFIED PATTERN
AND THE MOST RECENT GEFS/ECMWF ENSEMBLE GUIDANCE SHOW GOOD
CORRELATION TO NEXT THURSDAY.

DURING THIS SYNOPTIC TRANSITION...HIGH PRESSURE AND UPPER LEVEL
RIDGE WILL BE OVER THE NORTHEAST SATURDAY NIGHT BEFORE DEPARTING
LATE SUNDAY. LONGWAVE DIGGING TROUGH OVER THE CENTRAL CONUS WILL
PUSH A FEW SHORTWAVES THROUGH THE FLOW. FIRST ONE DEVELOPS A WEAK
COASTAL LOW MOVING TOWARDS THE REGION LATE MONDAY INTO TUESDAY.
THERE IS STILL SOME UNCERTAINTY WITH THE LOCATION OF THIS SYSTEM
BUT APPEARS THAT THERE WILL BE SNOW/WINTRY MIX IN THE INTERIOR. AS
THIS SYSTEM DEPARTS APPEARS AN ANOMALOUS LOW OVER THE GREAT LAKES
WILL DEVELOP A SECONDARY LOW /DOUBLE BARREL LOW/ CLOSER TO NEW
ENGLAND...PER ENSEMBLE GUIDANCE. STILL A GOOD AMOUNT OF SPREAD BUT
IF THIS DOUBLE LOW DOES DEVELOP THEN THE RAIN AND WIND ASPECT OF THE
SYSTEM INCREASES...DETAILS BELOW. STILL SOME UNCERTAINTY WITH THIS
PARTICULAR SYSTEM BUT WITH 2 TO 3 SD AWAY AND GENERAL MODEL
AGREEMENT HAVE HIGHER CONFIDENCE THIS SYSTEM WILL IMPACT SOUTHERN
NEW ENGLAND.

DETAILS...

SATURDAY NIGHT INTO SUNDAY...HIGH CONFIDENCE.

WEAK WAVE WILL MOVE THROUGH THE FLOW ON SATURDAY NIGHT AND WITH HIGH
PRESSURE SHIFTING EASTWARD EXPECT ONSHORE EASTERLY FLOW. GUIDANCE
CONTINUES TO SHOW QPF MOVING ONSHORE AND WITH MOISTURE AND THE LIFT
COULD SEE SNOW SHOWERS MOVING INLAND SATURDAY NIGHT INTO SUNDAY.
BIGGEST QUESTION IS WILL THE MOISTURE SATURATE ENOUGH TO -6C. IF NOT
THEN THE POTENTIAL FOR FREEZING DRIZZLE IS POSSIBLE. BELIEVE THAT
WITH A SOUTHERLY FLOW AT 850MB AND EASTERLY FLOW AT THE SURFACE WILL
ALLOW FOR THE PROFILE TO SATURATE. USUALLY YOU WOULD WANT SATURATION
UP TO -8C BUT BECAUSE OF SALT NUCLEI THE SNOW GROWTH REGION BEGINS
AT -5C OR -6C. APPEARS THAT THERE IS ENOUGH MOISTURE SO A QUICK HALF
INCH TO AN INCH IS POSSIBLE PER SOUNDINGS EAST OF THE WORCESTER
HILLS. HOWEVER BECAUSE IT IS A MORE ENE FLOW...PLYMOUTH COUNTY MAY
SEE 1 TO 2 INCHES IF THEY REMAIN COLD ENOUGH FOR SNOW...ESP DURING
THE DAY ON SUNDAY.

SNOW MAY OVERSPREAD ACROSS THE WEST DURING THE DAY IF THERE IS
ENOUGH MOISTURE. HOWEVER RIDGE BEGINS TO BUILD INTO THE REGION LATE
SUNDAY INTO SUNDAY NIGHT SO THE POTENTIAL FOR SNOW SHOWERS WILL BE
LIMITED DUE TO PRESSURE RISE.

MONDAY INTO TUESDAY...MODERATE CONFIDENCE.

WEAK COASTAL LOW PRESSURE SYSTEM WILL DEVELOP AND MOVE CLOSE TO THE
SOUTHERN NEW ENGLAND COASTLINE. THERE IS STILL DESCENT MODEL SPREAD
ON THE EXACT LOW TRACK BUT APPEARS THAT IT DOES WEAKEN AS IT
APPROACHES FROM THE MID-ATLANTIC. REGARDLESS THERE COULD ALLOW FOR
SHALLOW COLD AIR FROM THE DEPARTING TO HIGH TO STAY TRAP AND WITH
WARM AIR ALOFT MOVING INTO THE REGION...COULD SEE SNOW OR WINTRY
PRECIP ESP ACROSS THE HIGHER TERRAIN LATE MONDAY INTO TUESDAY
MORNING. BECAUSE OF THE MODEL SPREAD STILL HAVE DETAILS TO WORK OUT
BUT SOMETHING TO WATCH CLOSELY.

TEMPERATURES WILL SLOWLY BEGIN TO WARM ON TUESDAY AS SOUTHERLY FLOW
BECOMES DOMINATE OUT AHEAD OF STRONGER SYSTEM TO THE EAST. EASTERLY
FLOW WILL CONTINUE TO DOMINATE AT THE SURFACE WITH A EASTERLY LLJ
STRENGTHEN ABOUT 20-30KTS. TUESDAYS HIGH TIDE AT BOSTON WILL BE 11.6
DURING THE LATE MORNING...AND WITH PERSISTENT EASTERLY WINDS
ANTICIPATE AT LEAST MINOR COASTAL FLOODING. IF THIS SURFACE LOW
STRENGTHENS AND THE EASTERLY FLOW INCREASES THEN THE MASS EAST
COASTLINE WILL HAVE TO BE WATCHED CLOSELY DURING THE TUESDAY HIGH
TIDE.

WEDNESDAY INTO THURSDAY...HIGH CONFIDENCE IN SYSTEM LOW CONFIDENCE
ON DETAILS.

STRONG ANOMALOUS SYSTEM WILL STRENGTHEN OVER THE GREAT
LAKES...DEVELOPING A POTENTIAL SECONDARY SURFACE LOW JUST WEST OF
SOUTHERN NEW ENGLAND. STILL A LOT OF DETAILS TO WORK OUT AS THIS
SYSTEM IS STILL 5+ DAYS AWAY...HOWEVER ENSEMBLES SHOW THAT THIS
SYSTEM IS AROUND 2 TO 3 STANDARD DEVIATIONS ALLOWING FOR INCREASING
CONFIDENCE THAT A POTENT STORM WILL OCCUR. LATEST 00Z GUIDANCE SHOWS
THAT MOST PRECIP WILL BE LIQUID WITH A DEEP SUBTROPICAL CONNECTION
BACK ACROSS MEXICO... PW ANOMALIES FORECAST TO RISE TO BETWEEN +1 TO
+3 /OR HIGHER/...AND TEMPERATURES WELL ABOVE AVERAGE. IN FACT WE MAY
BE CLOSE AT BREAKING RECORD HIGH TEMPS IF TEMPS WARM TO 60F OR ABOVE
ON CHRISTMAS EVE.  AS THE SYSTEM WRAPS UP INTO CANADA...COLD AIR
ADVECTION SHOULD CIRCULATE AROUND AND BEGIN A TRANSITION FROM
SOUTHWEST TO NORTHEAST IN TURNING P-TYPE TO SNOW. HOWEVER LATEST
GUIDANCE DOES SHOW A QUICK MOVING DRY SLOT SO SNOWFALL WILL STRUGGLE
DUE TO LACK OF MOISTURE.

THIS SYSTEM IS QUITE POTENT SO WE WILL NEED TO WATCH FOR POTENTIAL
HAZARDS. CURRENTLY THINK THAT WE COULD SEE POSSIBLE URBAN FLOODING
ISSUES AS WELL AS WIND ISSUES. GUIDANCE RIGHT NOW IS SHOWING A 45 TO
55 KT JET AT 925 MB WHICH MAY WARRANT WIND ADVISORIES BUT THIS
SYSTEM COULD STRENGTHEN EVEN MORE SO A STRONGER JET IS POSSIBLE.

LASTLY COASTAL FLOODING ISSUES WILL NEED TO BE ADDRESS AS HIGH TIDE
ON WED AND THUS ARE 11.7 AND 11.5 RESPECTIVELY FOR BOSTON. ANY
EASTERLY COMPONENT WILL PUSH THE TIDE ABOVE FLOOD SO COASTAL
FLOODING IS POSSIBLE AS WELL AS BEACH EROSION. THE SOUTH COASTLINE
WILL ALSO HAVE TO BE WATCH CLOSELY. A VERY STRONG SOUTHERLY JET
WILL DEVELOP WED INTO THURSDAY AND WITH ASTRONOMICAL HIGH TIDE
COULD ALSO SEE MINOR TO MODERATE COASTAL FLOODING. ANOTHER ISSUE
IS THE POTENTIAL PRESSURE FALLS IF THIS SYSTEM STRENGTHENS EVEN
MORE...IT COULD ADD ANOTHER FOOT ONTO THE SURGE.

FRIDAY...LOW CONFIDENCE.

ONCE UPPER LOW MOVES INTO SOUTHERN CANADA...EXPECT A RATHER FAST
UPPER W FLOW IN PLACE. MAY SEE LEFTOVER SNOW SHOWERS BUT TEMPS WILL
FALL BACK CLOSE TO SEASONAL NORMS.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /TODAY THROUGH SATURDAY/...

THROUGH 00Z...LOW VFR AND MVFR CIGS WILL PERSIST...BUT BECOMING
VFR ALONG THE E MA COAST AS CLEARING MOVES IN FROM THE N.

TONIGHT...MODERATE CONFIDENCE. EXPECT PARTIAL CLEARING AND
BECOMING VFR DURING THE NIGHT AS LOW LEVEL DRY AIR MOVES SOUTH
ACROSS THE REGION. HOWEVER...LOW CLOUDS AND MVFR CIGS OVER THE
OUTER CAPE WILL GRADUALLY BACK IN ACROSS SE MA OVERNIGHT.

SATURDAY...MODERATE CONFIDENCE. MVFR CIGS ACROSS SE NEW ENG WILL
EXPAND WEST ACROSS THE REST OF THE COASTAL PLAIN THEN INTO THE
INTERIOR DURING THE AFTERNOON. CT VALLEY SHOULD REMAIN VFR.
SCATTERED RAIN SHOWERS WILL DEVELOP OVER CAPE COD WITH SNOW
SHOWERS INTO E MA BY LATE AFTERNOON.

SATURDAY NIGHT...MODERATE CONFIDENCE. WIDESPREAD MVFR CIGS WITH
POCKETS OF IFR E MA COAST. PERIODS OF LIGHT RAIN OVER CAPE COD
WITH LIGHT SNOW FURTHER INLAND ACROSS E MA. MINOR ACCUM POSSIBLE
ACROSS E MA JUST INLAND FROM THE IMMEDIATE COAST.

KBOS TERMINAL...MODERATE CONFIDENCE IN TAF. EXPECT VFR
TONIGHT...BEFORE MVFR CIGS DEVELOP SAT MORNING.

KBDL TERMINAL...MODERATE CONFIDENCE IN TAF.

OUTLOOK...SUNDAY THROUGH TUESDAY...

SUNDAY...HIGH CONFIDENCE. MAINLY VFR ACROSS CENTRAL AND WESTERN
AREAS. E OF ORH MAY SEE MVFR CONDITIONS IN SNOW SHOWERS.

MONDAY-TUESDAY...MODERATE CONFIDENCE. MAINLY VFR. MAY SEE LOCAL
MVFR IN WIDELY SCT RAIN/SNOW SHOWERS MON NIGHT/TUE.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /TODAY THROUGH SATURDAY/...HIGH CONFIDENCE.

HIGH PRESSURE BUILDING EAST INTO QUEBEC AND NORTHERN NEW ENGLAND
WILL KEEP WINDS/SEAS BELOW SCA THRESHOLDS THROUGH SATURDAY.
NORTHWEST WINDS TODAY WILL TURN NORTHEAST BY SATURDAY WITH GUSTS
BETWEEN 15 AND 20 KNOTS POSSIBLE AT TIMES.

OUTLOOK...SATURDAY THROUGH TUESDAY...MODERATE TO HIGH CONFIDENCE.

SATURDAY THROUGH MONDAY...WINDS AND SEAS BELOW SMALL CRAFT
CRITERIA.

MONDAY NIGHT AND TUESDAY...EXPECT E-NE WINDS GUSTING UP TO 25 KT
WITH SEAS BUILDING UP TO 5-7 FT...HIGHEST ON THE EASTERN OUTER
WATERS FROM COASTAL LOW.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...FRANK/DUNTEN
NEAR TERM...KJC
SHORT TERM...FRANK
LONG TERM...DUNTEN
AVIATION...KJC/DUNTEN
MARINE...FRANK/DUNTEN





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