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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 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 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 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 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 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




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




000
FXUS61 KBOX 191515
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
1015 AM 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/...
10 AM UPDATE...
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 /15Z FRIDAY THROUGH TUESDAY/...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /TODAY THROUGH SATURDAY/...

10 AM UPDATE...

REST OF TODAY...LOW VFR AND MVFR CIGS WILL PERSIST THROUGH THE
AFTERNOON.

TONIGHT...MODERATE CONFIDENCE. CIGS SHOULD GENERALLY BE VFR BUT
BRIEF PERIODS OF MARGINAL MVFR CIGS WILL BE POSSIBLE.
OTHERWISE...MVFR OCEAN EFFECT CIGS SHOULD DEVELOP TONIGHT ACROSS
THE SOUTHEAST NEW ENGLAND COAST AS SURFACE WINDS TURN MORE
NORTHERLY.

SATURDAY...MODERATE CONFIDENCE.  MVFR CIGS OVERSPREAD THE REST OF
COASTAL PLAIN AND EVENTUALLY EVEN INTO PORTIONS OF THE INTERIOR BY
LATE AFTERNOON.  SCATTERED OCEAN EFFECT LIGHT RAIN/SNOW SHOWERS WILL
OVERSPREAD THE SOUTHEAST NEW ENGLAND COAST WITH NORTHEAST SURFACE
WINDS.

KBOS TERMINAL...MODERATE TO HIGH CONFIDENCE.

KBDL TERMINAL...MODERATE TO HIGH CONFIDENCE.

OUTLOOK...SATURDAY NIGHT THROUGH TUESDAY...

SATURDAY NIGHT INTO 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/FRANK
SHORT TERM...FRANK
LONG TERM...DUNTEN
AVIATION...KJC/FRANK/DUNTEN
MARINE...FRANK/DUNTEN




000
FXUS61 KBOX 191515
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
1015 AM 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/...
10 AM UPDATE...
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 /15Z FRIDAY THROUGH TUESDAY/...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /TODAY THROUGH SATURDAY/...

10 AM UPDATE...

REST OF TODAY...LOW VFR AND MVFR CIGS WILL PERSIST THROUGH THE
AFTERNOON.

TONIGHT...MODERATE CONFIDENCE. CIGS SHOULD GENERALLY BE VFR BUT
BRIEF PERIODS OF MARGINAL MVFR CIGS WILL BE POSSIBLE.
OTHERWISE...MVFR OCEAN EFFECT CIGS SHOULD DEVELOP TONIGHT ACROSS
THE SOUTHEAST NEW ENGLAND COAST AS SURFACE WINDS TURN MORE
NORTHERLY.

SATURDAY...MODERATE CONFIDENCE.  MVFR CIGS OVERSPREAD THE REST OF
COASTAL PLAIN AND EVENTUALLY EVEN INTO PORTIONS OF THE INTERIOR BY
LATE AFTERNOON.  SCATTERED OCEAN EFFECT LIGHT RAIN/SNOW SHOWERS WILL
OVERSPREAD THE SOUTHEAST NEW ENGLAND COAST WITH NORTHEAST SURFACE
WINDS.

KBOS TERMINAL...MODERATE TO HIGH CONFIDENCE.

KBDL TERMINAL...MODERATE TO HIGH CONFIDENCE.

OUTLOOK...SATURDAY NIGHT THROUGH TUESDAY...

SATURDAY NIGHT INTO 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/FRANK
SHORT TERM...FRANK
LONG TERM...DUNTEN
AVIATION...KJC/FRANK/DUNTEN
MARINE...FRANK/DUNTEN



000
FXUS61 KBOX 191142
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
642 AM 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/...

A FEW MINOR UPDATES TO THE FORECAST TO ACCOUNT FOR CURRENT
CONDITIONS. CLOUDS CONTINUE TO BE PESKY WITH SOME BREAKS ACROSS
THE MASS EAST COASTLINE. BELIEVE THAT BREAKS WILL OCCUR LATE THIS
MORNING BUT THEN WILL FILL IN BY THE AFTERNOON FROM THE NORTHWEST
FLOW.


PREVIOUS DISCUSSION...

CONSIDERABLE LOW CLOUDINESS STILL COVERED SOUTHERN NEW ENGLAND VERY
EARLY THIS MORNING.  THIS A RESULT OF LOW LEVEL MOISTURE TRAPPED
BENEATH THE INVERSION.  OTHER THAN THE NAM MODEL...MOST OTHER
GUIDANCE DOES NOT HAVE A GOOD GRASP ON THESE CLOUDS.

THE MAIN QUESTION IS DO THESE CLOUDS HANG TOUGH TODAY UNDERNEATH THE
INVERSION OR BREAK UP?  SOMETIMES CLOUDS CAN BE VERY STUBBORN TO
DISSIPATE IN THESE PARTICULAR SITUATIONS.  GIVEN THE
UNCERTAINTY...WILL SHOW AN ABUNDANCE OF CLOUDS TODAY BUT ALSO THE
OPPORTUNITY FOR PEEKS OF SUNSHINE.  MODEL CROSS SECTIONS SHOW THE
BEST CHANCE FOR SOME PEEKS OF SUN WILL BE ACROSS EASTERN NEW
ENGLAND.  LATER SHIFTS WILL HAVE TO MONITOR SKY CONDITIONS CLOSELY
AND MAKE ANY ADJUSTMENTS AS NEEDED.

AS FOR TEMPS TODAY...HIGH PRESSURE BUILDING INTO EASTERN CANADA WILL
ALLOW SOME SHALLOW COLD AIR TO OOZE SOUTH.  THIS SHOULD HOLD HIGH
TEMPS IN THE 30S...BUT WITH MUCH LESS WIND THAN YESTERDAY NOT BAD
FOR MID DECEMBER STANDARDS.

&&

.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 PERSISENT 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 COMPONET 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 /12Z FRIDAY THROUGH TUESDAY/...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /TODAY THROUGH SATURDAY/...

TODAY AND TONIGHT...MODERATE CONFIDENCE.  A SCATTERED TO
BROKEN DECK OF CLOUDS WILL PROBABLY REMAIN IN PLACE TODAY.  CIGS
SHOULD GENERALLY BE VFR BUT BRIEF PERIODS OF MARGINAL MVFR CIGS WILL
BE POSSIBLE.  OTHERWISE...MVFR OCEAN EFFECT CIGS SHOULD DEVELOP
TONIGHT ACROSS THE SOUTHEAST NEW ENGLAND COAST AS SURFACE WINDS TURN
MORE NORTHERLY.

SATURDAY...MODERATE CONFIDENCE.  MVFR CIGS OVERSPREAD THE REST OF
COASTAL PLAIN AND EVENTUALLY EVEN INTO PORTIONS OF THE INTERIOR BY
LATE AFTERNOON.  SCATTERED OCEAN EFFECT LIGHT RAIN/SNOW SHOWERS WILL
OVERSPREAD THE SOUTHEAST NEW ENGLAND COAST WITH NORTHEAST SURFACE
WINDS.

KBOS TERMINAL...MODERATE TO HIGH CONFIDENCE.

KBDL TERMINAL...MODERATE TO HIGH CONFIDENCE.

OUTLOOK...SATURDAY NIGHT THROUGH TUESDAY...

SATURDAY NIGHT INTO 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...FRANK/DUNTEN
SHORT TERM...FRANK
LONG TERM...DUNTEN
AVIATION...FRANK/DUNTEN
MARINE...FRANK/DUNTEN



000
FXUS61 KBOX 190945
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
445 AM 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/...

4 AM UPDATE...

CONSIDERABLE LOW CLOUDINESS STILL COVERED SOUTHERN NEW ENGLAND VERY
EARLY THIS MORNING.  THIS A RESULT OF LOW LEVEL MOISTURE TRAPPED
BENEATH THE INVERSION.  OTHER THAN THE NAM MODEL...MOST OTHER
GUIDANCE DOES NOT HAVE A GOOD GRASP ON THESE CLOUDS.

THE MAIN QUESTION IS DO THESE CLOUDS HANG TOUGH TODAY UNDERNEATH THE
INVERSION OR BREAK UP?  SOMETIMES CLOUDS CAN BE VERY STUBBORN TO
DISSIPATE IN THESE PARTICULAR SITUATIONS.  GIVEN THE
UNCERTAINTY...WILL SHOW AN ABUNDANCE OF CLOUDS TODAY BUT ALSO THE
OPPORTUNITY FOR PEEKS OF SUNSHINE.  MODEL CROSS SECTIONS SHOW THE
BEST CHANCE FOR SOME PEEKS OF SUN WILL BE ACROSS EASTERN NEW
ENGLAND.  LATER SHIFTS WILL HAVE TO MONITOR SKY CONDITIONS CLOSELY
AND MAKE ANY ADJUSTMENTS AS NEEDED.

AS FOR TEMPS TODAY...HIGH PRESSURE BUILDING INTO EASTERN CANADA WILL
ALLOW SOME SHALLOW COLD AIR TO OOZE SOUTH.  THIS SHOULD HOLD HIGH
TEMPS IN THE 30S...BUT WITH MUCH LESS WIND THAN YESTERDAY NOT BAD
FOR MID DECEMBER STANDARDS.


&&

.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 PERSISENT 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 COMPONET 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 /10Z FRIDAY THROUGH TUESDAY/...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /TODAY THROUGH SATURDAY/...

TODAY AND TONIGHT...MODERATE CONFIDENCE.  A SCATTERED TO
BROKEN DECK OF CLOUDS WILL PROBABLY REMAIN IN PLACE TODAY.  CIGS
SHOULD GENERALLY BE VFR BUT BRIEF PERIODS OF MARGINAL MVFR CIGS WILL
BE POSSIBLE.  OTHERWISE...MVFR OCEAN EFFECT CIGS SHOULD DEVELOP
TONIGHT ACROSS THE SOUTHEAST NEW ENGLAND COAST AS SURFACE WINDS TURN
MORE NORTHERLY.

SATURDAY...MODERATE CONFIDENCE.  MVFR CIGS OVERSPREAD THE REST OF
COASTAL PLAIN AND EVENTUALLY EVEN INTO PORTIONS OF THE INTERIOR BY
LATE AFTERNOON.  SCATTERED OCEAN EFFECT LIGHT RAIN/SNOW SHOWERS WILL
OVERSPREAD THE SOUTHEAST NEW ENGLAND COAST WITH NORTHEAST SURFACE
WINDS.

KBOS TERMINAL...MODERATE TO HIGH CONFIDENCE.

KBDL TERMINAL...MODERATE TO HIGH CONFIDENCE.

OUTLOOK...SATURDAY NIGHT THROUGH TUESDAY...

SATURDAY NIGHT INTO 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...FRANK
SHORT TERM...FRANK
LONG TERM...DUNTEN
AVIATION...FRANK/DUNTEN
MARINE...FRANK/DUNTEN




000
FXUS61 KBOX 190945
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
445 AM 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/...

4 AM UPDATE...

CONSIDERABLE LOW CLOUDINESS STILL COVERED SOUTHERN NEW ENGLAND VERY
EARLY THIS MORNING.  THIS A RESULT OF LOW LEVEL MOISTURE TRAPPED
BENEATH THE INVERSION.  OTHER THAN THE NAM MODEL...MOST OTHER
GUIDANCE DOES NOT HAVE A GOOD GRASP ON THESE CLOUDS.

THE MAIN QUESTION IS DO THESE CLOUDS HANG TOUGH TODAY UNDERNEATH THE
INVERSION OR BREAK UP?  SOMETIMES CLOUDS CAN BE VERY STUBBORN TO
DISSIPATE IN THESE PARTICULAR SITUATIONS.  GIVEN THE
UNCERTAINTY...WILL SHOW AN ABUNDANCE OF CLOUDS TODAY BUT ALSO THE
OPPORTUNITY FOR PEEKS OF SUNSHINE.  MODEL CROSS SECTIONS SHOW THE
BEST CHANCE FOR SOME PEEKS OF SUN WILL BE ACROSS EASTERN NEW
ENGLAND.  LATER SHIFTS WILL HAVE TO MONITOR SKY CONDITIONS CLOSELY
AND MAKE ANY ADJUSTMENTS AS NEEDED.

AS FOR TEMPS TODAY...HIGH PRESSURE BUILDING INTO EASTERN CANADA WILL
ALLOW SOME SHALLOW COLD AIR TO OOZE SOUTH.  THIS SHOULD HOLD HIGH
TEMPS IN THE 30S...BUT WITH MUCH LESS WIND THAN YESTERDAY NOT BAD
FOR MID DECEMBER STANDARDS.


&&

.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 PERSISENT 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 COMPONET 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 /10Z FRIDAY THROUGH TUESDAY/...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /TODAY THROUGH SATURDAY/...

TODAY AND TONIGHT...MODERATE CONFIDENCE.  A SCATTERED TO
BROKEN DECK OF CLOUDS WILL PROBABLY REMAIN IN PLACE TODAY.  CIGS
SHOULD GENERALLY BE VFR BUT BRIEF PERIODS OF MARGINAL MVFR CIGS WILL
BE POSSIBLE.  OTHERWISE...MVFR OCEAN EFFECT CIGS SHOULD DEVELOP
TONIGHT ACROSS THE SOUTHEAST NEW ENGLAND COAST AS SURFACE WINDS TURN
MORE NORTHERLY.

SATURDAY...MODERATE CONFIDENCE.  MVFR CIGS OVERSPREAD THE REST OF
COASTAL PLAIN AND EVENTUALLY EVEN INTO PORTIONS OF THE INTERIOR BY
LATE AFTERNOON.  SCATTERED OCEAN EFFECT LIGHT RAIN/SNOW SHOWERS WILL
OVERSPREAD THE SOUTHEAST NEW ENGLAND COAST WITH NORTHEAST SURFACE
WINDS.

KBOS TERMINAL...MODERATE TO HIGH CONFIDENCE.

KBDL TERMINAL...MODERATE TO HIGH CONFIDENCE.

OUTLOOK...SATURDAY NIGHT THROUGH TUESDAY...

SATURDAY NIGHT INTO 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...FRANK
SHORT TERM...FRANK
LONG TERM...DUNTEN
AVIATION...FRANK/DUNTEN
MARINE...FRANK/DUNTEN




000
FXUS61 KBOX 190928
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
428 AM 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/...

4 AM UPDATE...

CONSIDERABLE LOW CLOUDINESS STILL COVERED SOUTHERN NEW ENGLAND VERY
EARLY THIS MORNING.  THIS A RESULT OF LOW LEVEL MOISTURE TRAPPED
BENEATH THE INVERSION.  OTHER THAN THE NAM MODEL...MOST OTHER
GUIDANCE DOES NOT HAVE A GOOD GRASP ON THESE CLOUDS.

THE MAIN QUESTION IS DO THESE CLOUDS HANG TOUGH TODAY UNDERNEATH THE
INVERSION OR BREAK UP?  SOMETIMES CLOUDS CAN BE VERY STUBBORN TO
DISSIPATE IN THESE PARTICULAR SITUATIONS.  GIVEN THE
UNCERTAINTY...WILL SHOW AN ABUNDANCE OF CLOUDS TODAY BUT ALSO THE
OPPORTUNITY FOR PEEKS OF SUNSHINE.  MODEL CROSS SECTIONS SHOW THE
BEST CHANCE FOR SOME PEEKS OF SUN WILL BE ACROSS EASTERN NEW
ENGLAND.  LATER SHIFTS WILL HAVE TO MONITOR SKY CONDITIONS CLOSELY
AND MAKE ANY ADJUSTMENTS AS NEEDED.

AS FOR TEMPS TODAY...HIGH PRESSURE BUILDING INTO EASTERN CANADA WILL
ALLOW SOME SHALLOW COLD AIR TO OOZE SOUTH.  THIS SHOULD HOLD HIGH
TEMPS IN THE 30S...BUT WITH MUCH LESS WIND THAN YESTERDAY NOT BAD
FOR MID DECEMBER STANDARDS.


&&

.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 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 PERSISENT 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 COMPONET 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 /10Z FRIDAY THROUGH TUESDAY/...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /TODAY THROUGH SATURDAY/...

TODAY AND TONIGHT...LOW TO MODERATE CONFIDENCE.  A SCATTERED TO
BROKEN DECK OF CLOUDS WILL PROBABLY REMAIN IN PLACE TODAY.  CIGS
SHOULD GENERALLY BE VFR BUT BRIEF PERIODS OF MARGINAL MVFR CIGS WILL
BE POSSIBLE.  OTHERWISE...MVFR OCEAN EFFECT CIGS SHOULD DEVELOP
TONIGHT ACROSS THE SOUTHEAST NEW ENGLAND COAST AS SURFACE WINDS TURN
MORE NORTHERLY.

SATURDAY...MODERATE CONFIDENCE.  MVFR CIGS OVERSPREAD THE REST OF
COASTAL PLAIN AND EVENTUALLY EVEN INTO PORTIONS OF THE INTERIOR BY
LATE AFTERNOON.  SCATTERED OCEAN EFFECT LIGHT RAIN/SNOW SHOWERS WILL
OVERSPREAD THE SOUTHEAST NEW ENGLAND COAST WITH NORTHEAST SURFACE
WINDS.

KBOS TERMINAL...MODERATE TO HIGH CONFIDENCE.

KBDL TERMINAL...MODERATE TO HIGH CONFIDENCE.

OUTLOOK...SATURDAY NIGHT THROUGH TUESDAY...

SATURDAY NIGHT INTO 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...FRANK
SHORT TERM...FRANK
LONG TERM...DUNTEN
AVIATION...FRANK/DUNTEN
MARINE...FRANK/DUNTEN




000
FXUS61 KBOX 190928
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
428 AM 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/...

4 AM UPDATE...

CONSIDERABLE LOW CLOUDINESS STILL COVERED SOUTHERN NEW ENGLAND VERY
EARLY THIS MORNING.  THIS A RESULT OF LOW LEVEL MOISTURE TRAPPED
BENEATH THE INVERSION.  OTHER THAN THE NAM MODEL...MOST OTHER
GUIDANCE DOES NOT HAVE A GOOD GRASP ON THESE CLOUDS.

THE MAIN QUESTION IS DO THESE CLOUDS HANG TOUGH TODAY UNDERNEATH THE
INVERSION OR BREAK UP?  SOMETIMES CLOUDS CAN BE VERY STUBBORN TO
DISSIPATE IN THESE PARTICULAR SITUATIONS.  GIVEN THE
UNCERTAINTY...WILL SHOW AN ABUNDANCE OF CLOUDS TODAY BUT ALSO THE
OPPORTUNITY FOR PEEKS OF SUNSHINE.  MODEL CROSS SECTIONS SHOW THE
BEST CHANCE FOR SOME PEEKS OF SUN WILL BE ACROSS EASTERN NEW
ENGLAND.  LATER SHIFTS WILL HAVE TO MONITOR SKY CONDITIONS CLOSELY
AND MAKE ANY ADJUSTMENTS AS NEEDED.

AS FOR TEMPS TODAY...HIGH PRESSURE BUILDING INTO EASTERN CANADA WILL
ALLOW SOME SHALLOW COLD AIR TO OOZE SOUTH.  THIS SHOULD HOLD HIGH
TEMPS IN THE 30S...BUT WITH MUCH LESS WIND THAN YESTERDAY NOT BAD
FOR MID DECEMBER STANDARDS.


&&

.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 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 PERSISENT 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 COMPONET 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 /10Z FRIDAY THROUGH TUESDAY/...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /TODAY THROUGH SATURDAY/...

TODAY AND TONIGHT...LOW TO MODERATE CONFIDENCE.  A SCATTERED TO
BROKEN DECK OF CLOUDS WILL PROBABLY REMAIN IN PLACE TODAY.  CIGS
SHOULD GENERALLY BE VFR BUT BRIEF PERIODS OF MARGINAL MVFR CIGS WILL
BE POSSIBLE.  OTHERWISE...MVFR OCEAN EFFECT CIGS SHOULD DEVELOP
TONIGHT ACROSS THE SOUTHEAST NEW ENGLAND COAST AS SURFACE WINDS TURN
MORE NORTHERLY.

SATURDAY...MODERATE CONFIDENCE.  MVFR CIGS OVERSPREAD THE REST OF
COASTAL PLAIN AND EVENTUALLY EVEN INTO PORTIONS OF THE INTERIOR BY
LATE AFTERNOON.  SCATTERED OCEAN EFFECT LIGHT RAIN/SNOW SHOWERS WILL
OVERSPREAD THE SOUTHEAST NEW ENGLAND COAST WITH NORTHEAST SURFACE
WINDS.

KBOS TERMINAL...MODERATE TO HIGH CONFIDENCE.

KBDL TERMINAL...MODERATE TO HIGH CONFIDENCE.

OUTLOOK...SATURDAY NIGHT THROUGH TUESDAY...

SATURDAY NIGHT INTO 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...FRANK
SHORT TERM...FRANK
LONG TERM...DUNTEN
AVIATION...FRANK/DUNTEN
MARINE...FRANK/DUNTEN



000
FXUS61 KBOX 190613
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
113 AM EST FRI DEC 19 2014

.SYNOPSIS...

DRY AND SEASONABLE CONDITIONS WILL PREVAIL FRIDAY. AN UPPER LEVEL
DISTURBANCE AND MOIST NORTHEAST FLOW WILL BRING SOME LIGHT
PRECIPITATION SATURDAY INTO SUNDAY. LOW PRESSURE WILL LIKELY PASS
WELL SOUTH OF THE REGION TUESDAY...BUT STILL COULD BRING A PERIOD
OF LIGHT PRECIPITATION. A MUCH STRONGER STORM IS LIKELY TO BRING
HEAVY RAIN AND WIND TO SOUTHERN NEW ENGLAND WEDNESDAY INTO
WEDNESDAY EVENING. DRY BUT VERY WINDY CONDITIONS FOLLOW FOR
CHRISTMAS DAY.

&&

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

110 AM UPDATE...

AN ABUNDANCE OF LOW CLOUDS REMAIN IN PLACE ACROSS MOST OF THE REGION
VERY EARLY THIS MORNING...TRAPPED BELOW THE SHALLOW INVERSION.
LITTLE CHANGE EXPECTED THROUGH DAYBREAK.  LOW TEMPS SHOULD BOTTOM
OUT IN THE 20S TO THE LOWER 30S.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SATURDAY/...
FRIDAY...
HIGH PRES BUILDS ACROSS THE GRT LAKES WITH NW FLOW ACROSS NEW
ENG. TRICKY CLOUD FORECAST AS NAM INDICATING LOW LEVEL MOISTURE
TRAPPED BELOW INVERSION WITH WIDESPREAD LOW CLOUDS...WHILE GFS AND
ECMWF ARE DRIER IN THE LOW LEVELS. GIVEN LOW LEVEL FLOW IS STILL
NW...WE WILL LEAN MORE OPTIMISTIC THAN NAM WITH A MIX OF CLOUDS
AND SUN EXPECTED. TEMPS WILL LIKELY BE 3-5 DEGREES COLDER THAN
TODAY GIVEN COOLING AT 925 MB...WITH MAX TEMPS RANGING FROM NEAR
30 HIGHER TERRAIN IN NORTHERN AND WESTERN MA TO UPPER 30S IN THE
COASTAL PLAIN.

FRIDAY NIGHT...
MID LEVEL SHORTWAVE MOVES INTO W NEW ENG TOWARD DAYBREAK...BUT
FORCING IS WEAK THROUGH MOST OF THE NIGHT AND MOISTURE IS LIMITED
SO EXPECTING A MAINLY DRY NIGHT. HOWEVER...AS HIGH PRES BUILDS
EASTWARD ACROSS QUEBEC LOW LEVEL WINDS BECOME NE AND MODELS
INDICATE INCREASING LOW MOISTURE BACKING IN ACROSS SE NEW ENG
OVERNIGHT. DELTA T FROM SST TO THE TOP OF THE MIXED LAYER IS
AROUND 13C WHICH IS MARGINAL FOR OCEAN EFFECT AND OCEAN INDUCED
CAPES ARE NOT IMPRESSIVE...BUT LOW LEVEL LAPSE RATES ARE
INCREASING. MODELS DO SHOW SOME LIGHT QPF DEVELOPING SO THERE MAY
BE A FEW SNOW SHOWERS DEVELOPING OVER CAPE COD AND ACK OVERNIGHT
AND WE HAVE SOME LOW CHC POPS.

&&

.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
HIGHLIGHTS...

* SCT LIGHT SNOW/RAIN SHOWERS SAT INTO SUN...WITH A PERIOD OF
  DRIZZLE/FREEZING DRIZZLE POSSIBLE SAT NIGHT INTO SUN MORNING
* WEAK WAVE OF LOW PRESSURE WILL PASS WELL OFFSHORE TUE BUT COULD
  STILL SEE LIGHT PRECIP
* ANOMALOUSLY STRONG STORM SYSTEM WILL BRING HEAVY RAIN...GUSTY
  WINDS AND COASTAL CONCERNS AROUND CHRISTMAS EVE

OVERVIEW AND MODEL PREFERENCES...
MEDIUM RANGE MODELS CONTINUE IN PRETTY GOOD AGREEMENT ON LARGE
SCALE AND UPPER LEVEL FEATURES THROUGH MOST OF THE FORECAST
PERIOD.

MODELS AND ENSEMBLES CONTINUE TO SIGNAL WEAK SHORT WAVES THAT
TRANSLATE ACROSS THE REGION EARLY IN THIS PERIOD...WITH A RATHER
POTENT BUT FAST MOVING ONE FOR SAT NIGHT/SUN TIMEFRAME WHICH IS
AIDED WITH LOW LEVEL ONSHORE MOISTURE...WITH A SECOND WEAK LOW FOR
LATE MON INTO TUE BRINGING ANOTHER PERIOD OF LIGHT PRECIP.

STILL QUITE A FEW PLACEMENT AND TIMING ISSUES WITH THE EVOLUTION
OF AN ANOMALOUSLY DEEP H5 CUTOFF LOW DEVELOPING ACROSS THE WESTERN
GREAT LAKES AROUND THE MON-TUE TIMEFRAME...THEN ROTATES NE
SOMEWHERE ACROSS S CENTRAL CANADA ON CHRISTMAS DAY. BIG
IMPLICATIONS WITH THE ASSOCIATED LONG WAVE TROUGH. GUIDANCE
CONTINUES TO INDICATE THE TROUGH BECOMING NEGATIVELY TILTED ACROSS
THE MID ATLC OR SE U.S. LATE IN THIS PERIOD. SECONDARY/ TRIPLE
POINT LOW FORMS ON SURFACE FRONT OVER THE EASTERN GULF AROUND
TUESDAY...THEN WORKS UP ACROSS EASTERN PORTIONS OF THE SE AND MID
ATLC STATES. QUESTION IS IF THIS LOW APPROACHES WESTERN PORTIONS
OF NEW ENGLAND WED NIGHT.

STILL SEE THE SIGNALS FOR A FAST MOVING STORM WITH MULTIPLE
IMPACTS POSSIBLE...INCLUDING PERIOD OF HEAVY RAINFALL AND STRONG
WIND GUSTS...FIRST FROM THE SOUTH THEN SHIFTING TO THE WEST. COULD
EVEN SEE SOME COASTAL IMPACTS DURING THE HIGH TIDE CYCLE DURING
WED. TIMING REMAINS AN ISSUE...AS ONE WOULD EXPECT THIS FAR OUT.
MODEL GUIDANCE STILL DOING A RATHER GOOD JOB HANDLING GENERAL
FEATURES OF THIS SYSTEM AT THIS POINT.

USED A BLEND OF THE AVAILABLE GUIDANCE ALONG WITH WPC GUIDANCE.

DETAILS...

SATURDAY INTO SUNDAY...HIGH CONFIDENCE.
HIGH PRES AT THE SURFACE AND ALOFT MOVES ACROSS QUEBEC INTO THE
MARITIMES DURING THIS WEEKEND...THEN TENDS TO SLOW ITS EASTWARD
PROGRESS WITH BLOCKING OVER THE WESTERN ATLC. RATHER POTENT SHORT
WAVE UNDERNEATH THE UPPER SYSTEM MOVES ACROSS THE REGION...AIDED
BY A LOW LEVEL E-NE WIND IN PLACE. A LOT OF LOW LEVEL MOISTURE IN
PLACE AS SEEN ON BUFKIT MODEL SOUNDINGS...SO WILL SEE SOME LIGHT
RAIN/SNOW SHOWERS DEVELOP FROM E-W DURING SATURDAY. EXPECTING
LITTLE IF ANY SNOW ACCUMULATIONS DURING SAT.

HOWEVER...AS TEMPS FALL BACK SAT NIGHT...ALONG WITH THE DEEP LOW
LEVEL MOISTURE FEED...WILL ALSO SEE AREAS OF DRIZZLE DEVELOP. BIG
PROBLEM WILL BE JUST AWAY FROM THE COAST WHERE TEMPS FALL BELOW
FREEZING WHICH MAY MEAN FREEZING DRIZZLE. DOES NOT TAKE MUCH TO
GET GLAZING ESPECIALLY ON UNTREATED SURFACES. WILL NEED TO MONITOR
THIS CLOSELY FOR POSSIBLE WINTER WEATHER HEADLINES ACROSS INTERIOR
E MA INTO RI...POSSIBLY EVEN FURTHER W. WITH THE LIGHT
SNOW...MIGHT SEE UP TO 1/2 INCH ACCUMULATIONS SAT NIGHT INTO SUN
MORNING.

ON SUNDAY...DRIZZLE WILL TAPER OFF DURING THE MORNING...THOUGH
LEFTOVER RAIN/SNOW SHOWERS WILL LINGER THOUGH TEND TO TAPER OFF
DURING THE AFTERNOON.

MONDAY INTO TUESDAY...MODERATE CONFIDENCE.
ANOTHER COASTAL LOW LOOKS TO DEVELOP OFF THE SE U.S. COAST
AND...AS UPPER LEVEL TROUGH BEGINS TO DIG ACROSS THE CENTRAL
U.S...WILL SHIFT TO THE E-NE UNDERNEATH THE UPPER RIDGE. THE
MARITIMES SURFACE HIGH REMAINS PRETTY MUCH IN PLACE...WHICH WILL
HELP SHIFT THE MAIN EFFECTS OF THIS LOW WELL OFFSHORE /SE OF THE
40N/70W BENCHMARK/. HOWEVER...MODELS CONTINUE TO SIGNAL LIGHT
PRECIP REACHING THE COAST MAINLY MON NIGHT INTO TUE. EXPECT MAINLY
MIXED RAIN/SNOW SHOWERS WITH SPOTTY BRIEF PERIODS OF FREEZING
PRECIP AROUND DAYBREAK TUE ACROSS N CT/N RI INTO S CENTRAL MA.
EXPECT HIGH TEMPS ON TUE TO RUN ABOUT 5 DEGS ABOVE SEASONAL NORMS
AS WINDS BEGIN TO SHIFT MORE S- SE...THOUGH SOME TIMING ISSUES IN
PLACE FOR WIND SHIFT AMONGST OP MODELS.

ONCE THE LOW EXITS LATE TUE...WILL ALREADY START TO SEE MOISTURE
FEED UP THE COAST FROM THE DEVELOPING GULF LOW...SO NOT MUCH OF A
BREAK IN THE PRECIP BETWEEN SYSTEMS.

TUESDAY/S LATE MORNING HIGH TIDE WILL RUN UP TO 11.6 FT IN BOSTON
AND...WITH ANY EASTERLY WIND FLOW...THIS MAY CAUSE MINOR COASTAL
FLOODING. WILL MONITOR THIS ASPECT.

WEDNESDAY AND CHRISTMAS DAY...HIGH CONFIDENCE IN SYSTEM...LOW
CONFIDENCE ON DETAILS.

SECONDARY LOW FROM THE PARENT OVER THE NORTHERN GREAT LAKES
DEEPENS AS IT SHIFTS N. MODELS TRY TO PUSH THIS SYSTEM CLOSE TO OR
JUST INTO WESTERN NEW ENGLAND LATE WED/WED NIGHT...THOUGH STILL
TIMING ISSUES IN PLACE. AT THIS POINT...WILL SEE HEAVIEST SLUG OF
PRECIP MOVING ACROSS LATE WED INTO WED EVENING. GOOD TROPICAL
CONNECTION CONTINUES WITH PWATS FROM 1.25 TO 1.4 INCHES...RUNNING
ABOUT +2SD TO +3SD ABOVE NORMAL FOR LATE DECEMBER. GOOD SHOT OF
MILD AIR WORKS IN ON SE-S WINDS. MODELS CONTINUE TO SIGNAL H925
AND H85 FROM 50-65 KT...AND AT LEAST SOME WILL MIX DOWN ESPECIALLY
IF THE LOW PRES PASSES CLOSER /WITH RAPIDLY FALLING PRESSURE/.
HAVE HIGHS ON WED UP TO THE LOWER 50S ACROSS EASTERN AND SOUTHERN
AREAS...BUT COULD BE EVEN HIGHER WITH STRONG ONSHORE WINDS.

CURRENT TIMING SUGGESTS THE DRY SLOT SHOULD WORK INTO THE REGION
LATE WED NIGHT INTO CHRISTMAS MORNING...SO PRECIP SHOULD END. WILL
STILL SEE GUSTY WINDS...THOUGH QUICKLY SHIFTING TO W-SW AND
GUSTING UP TO 25-30 KT...HIGHEST ALONG THE S COAST.

MAY NEED HEADLINES WITH THIS SYSTEM...WITH POSSIBLE URBAN/POOR
DRAINAGE FLOODING IN HEAVY RAINFALL WED/WED NIGHT...STRONG WINDS
BOTH WED AND THU...AND MAYBE EVEN FOR COASTAL CONCERNS. NOTING
ASTRO HIGH TIDES CONTINUE /11.7 AND 11.5 FT AT BOSTON
RESPECTIVELY/... THOUGH TIMING OF WIND SHIFT MAY COME INTO PLAY
FOR CHRISTMAS EVE INTO CHRISTMAS MORNING.

FRIDAY...LOW CONFIDENCE MAINLY FOR TIMING.
ONCE UPPER LOW MOVES INTO SOUTHERN CANADA...EXPECT A RATHER FAST
UPPER W FLOW IN PLACE. MAY SEE LEFTOVER SNOW SHOWERS ACROSS THE E
SLOPES OF THE BERKSHIRES INTO THE MONADNOCKS. TEMPS WILL FALL BACK
CLOSE TO SEASONAL NORMS. ANOTHER LOW MIGHT MOVE INTO W NY STATE
FRI NIGHT.

&&

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

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

SHORT TERM /TODAY THROUGH SATURDAY/...

TODAY AND TONIGHT...LOW TO MODERATE CONFIDENCE.  A BROKEN DECK OF
CLOUDS WILL PROBABLY REMAIN IN PLACE TODAY.  OVERALL...OUR
CONFIDENCE IN SKY COVER IS BELOW NORMAL BUT CEILINGS SHOULD VARY
BETWEEN LOW END VFR TO MVFR THROUGH THE AFTERNOON.  PERHAPS SOME OF
THE CLOUDS SCATTER OUT THIS EVENING...BUT AGAIN THAT IS UNCERTAIN.
OCEAN EFFECT CLOUDINESS WILL DEVELOP ACROSS THE CAPE/ACK AS WINDS
TURN TO A MORE NORTHERLY DIRECTION.

SATURDAY...MODERATE CONFIDENCE.  MVFR CIGS OVERSPREAD THE COASTAL
PLAIN AND EVENTUALLY EVEN INTO PORTIONS OF THE INTERIOR BY LATE
AFTERNOON.  SCATTERED OCEAN EFFECT LIGHT RAIN/SNOW SHOWERS WILL
OVERSPREAD THE SOUTHEAST NEW ENGLAND COAST WITH NORTHEAST SURFACE
WINDS.

OUTLOOK...SATURDAY NIGHT THROUGH TUESDAY...

SATURDAY NIGHT INTO SUNDAY...HIGH CONFIDENCE. MAINLY VFR ACROSS
CENTRAL AND WESTERN AREAS. E MA INTO RI...AREAS MVFR CIGS/VSBYS IN
ANY RAIN/SNOW SHOWERS...AREAS OF DRIZZLE SAT NIGHT INTO SUN MORNING.

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 FRIDAY NIGHT/...HIGH CONFIDENCE.

110 AM UPDATE...

OVERNIGHT...NW WINDS CONTINUE TO GRADUALLY DIMINISH AS PRESSURE
GRADIENT WEAKENS.  LET SCA HEADLINES EXPIRE FOR SOUNDS AND
BAYS...BUT THEY CONTINUE INTO THE MORNING FOR LEFT OVER SEAS.

FRIDAY...NW WINDS WILL BE BELOW SCA THRESHOLDS...BUT HAZARDOUS
SEAS WILL CONTINUE THROUGH THE MORNING OVER THE OUTER EASTERN
WATERS...BEFORE SUBSIDING BELOW SCA. WILL LIKELY NEED TO EXTEND
THE SCA FOR SEAS INTO FRI MORNING.

FRIDAY NIGHT...N/NW WINDS AND SEAS BELOW SCA.

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.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR
     ANZ250-254>256.

&&

$$
SYNOPSIS...KJC/EVT
NEAR TERM...FRANK
SHORT TERM...KJC
LONG TERM...EVT
AVIATION...FRANK/EVT
MARINE...FRANK/KJC/EVT



000
FXUS61 KBOX 190613
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
113 AM EST FRI DEC 19 2014

.SYNOPSIS...

DRY AND SEASONABLE CONDITIONS WILL PREVAIL FRIDAY. AN UPPER LEVEL
DISTURBANCE AND MOIST NORTHEAST FLOW WILL BRING SOME LIGHT
PRECIPITATION SATURDAY INTO SUNDAY. LOW PRESSURE WILL LIKELY PASS
WELL SOUTH OF THE REGION TUESDAY...BUT STILL COULD BRING A PERIOD
OF LIGHT PRECIPITATION. A MUCH STRONGER STORM IS LIKELY TO BRING
HEAVY RAIN AND WIND TO SOUTHERN NEW ENGLAND WEDNESDAY INTO
WEDNESDAY EVENING. DRY BUT VERY WINDY CONDITIONS FOLLOW FOR
CHRISTMAS DAY.

&&

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

110 AM UPDATE...

AN ABUNDANCE OF LOW CLOUDS REMAIN IN PLACE ACROSS MOST OF THE REGION
VERY EARLY THIS MORNING...TRAPPED BELOW THE SHALLOW INVERSION.
LITTLE CHANGE EXPECTED THROUGH DAYBREAK.  LOW TEMPS SHOULD BOTTOM
OUT IN THE 20S TO THE LOWER 30S.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SATURDAY/...
FRIDAY...
HIGH PRES BUILDS ACROSS THE GRT LAKES WITH NW FLOW ACROSS NEW
ENG. TRICKY CLOUD FORECAST AS NAM INDICATING LOW LEVEL MOISTURE
TRAPPED BELOW INVERSION WITH WIDESPREAD LOW CLOUDS...WHILE GFS AND
ECMWF ARE DRIER IN THE LOW LEVELS. GIVEN LOW LEVEL FLOW IS STILL
NW...WE WILL LEAN MORE OPTIMISTIC THAN NAM WITH A MIX OF CLOUDS
AND SUN EXPECTED. TEMPS WILL LIKELY BE 3-5 DEGREES COLDER THAN
TODAY GIVEN COOLING AT 925 MB...WITH MAX TEMPS RANGING FROM NEAR
30 HIGHER TERRAIN IN NORTHERN AND WESTERN MA TO UPPER 30S IN THE
COASTAL PLAIN.

FRIDAY NIGHT...
MID LEVEL SHORTWAVE MOVES INTO W NEW ENG TOWARD DAYBREAK...BUT
FORCING IS WEAK THROUGH MOST OF THE NIGHT AND MOISTURE IS LIMITED
SO EXPECTING A MAINLY DRY NIGHT. HOWEVER...AS HIGH PRES BUILDS
EASTWARD ACROSS QUEBEC LOW LEVEL WINDS BECOME NE AND MODELS
INDICATE INCREASING LOW MOISTURE BACKING IN ACROSS SE NEW ENG
OVERNIGHT. DELTA T FROM SST TO THE TOP OF THE MIXED LAYER IS
AROUND 13C WHICH IS MARGINAL FOR OCEAN EFFECT AND OCEAN INDUCED
CAPES ARE NOT IMPRESSIVE...BUT LOW LEVEL LAPSE RATES ARE
INCREASING. MODELS DO SHOW SOME LIGHT QPF DEVELOPING SO THERE MAY
BE A FEW SNOW SHOWERS DEVELOPING OVER CAPE COD AND ACK OVERNIGHT
AND WE HAVE SOME LOW CHC POPS.

&&

.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
HIGHLIGHTS...

* SCT LIGHT SNOW/RAIN SHOWERS SAT INTO SUN...WITH A PERIOD OF
  DRIZZLE/FREEZING DRIZZLE POSSIBLE SAT NIGHT INTO SUN MORNING
* WEAK WAVE OF LOW PRESSURE WILL PASS WELL OFFSHORE TUE BUT COULD
  STILL SEE LIGHT PRECIP
* ANOMALOUSLY STRONG STORM SYSTEM WILL BRING HEAVY RAIN...GUSTY
  WINDS AND COASTAL CONCERNS AROUND CHRISTMAS EVE

OVERVIEW AND MODEL PREFERENCES...
MEDIUM RANGE MODELS CONTINUE IN PRETTY GOOD AGREEMENT ON LARGE
SCALE AND UPPER LEVEL FEATURES THROUGH MOST OF THE FORECAST
PERIOD.

MODELS AND ENSEMBLES CONTINUE TO SIGNAL WEAK SHORT WAVES THAT
TRANSLATE ACROSS THE REGION EARLY IN THIS PERIOD...WITH A RATHER
POTENT BUT FAST MOVING ONE FOR SAT NIGHT/SUN TIMEFRAME WHICH IS
AIDED WITH LOW LEVEL ONSHORE MOISTURE...WITH A SECOND WEAK LOW FOR
LATE MON INTO TUE BRINGING ANOTHER PERIOD OF LIGHT PRECIP.

STILL QUITE A FEW PLACEMENT AND TIMING ISSUES WITH THE EVOLUTION
OF AN ANOMALOUSLY DEEP H5 CUTOFF LOW DEVELOPING ACROSS THE WESTERN
GREAT LAKES AROUND THE MON-TUE TIMEFRAME...THEN ROTATES NE
SOMEWHERE ACROSS S CENTRAL CANADA ON CHRISTMAS DAY. BIG
IMPLICATIONS WITH THE ASSOCIATED LONG WAVE TROUGH. GUIDANCE
CONTINUES TO INDICATE THE TROUGH BECOMING NEGATIVELY TILTED ACROSS
THE MID ATLC OR SE U.S. LATE IN THIS PERIOD. SECONDARY/ TRIPLE
POINT LOW FORMS ON SURFACE FRONT OVER THE EASTERN GULF AROUND
TUESDAY...THEN WORKS UP ACROSS EASTERN PORTIONS OF THE SE AND MID
ATLC STATES. QUESTION IS IF THIS LOW APPROACHES WESTERN PORTIONS
OF NEW ENGLAND WED NIGHT.

STILL SEE THE SIGNALS FOR A FAST MOVING STORM WITH MULTIPLE
IMPACTS POSSIBLE...INCLUDING PERIOD OF HEAVY RAINFALL AND STRONG
WIND GUSTS...FIRST FROM THE SOUTH THEN SHIFTING TO THE WEST. COULD
EVEN SEE SOME COASTAL IMPACTS DURING THE HIGH TIDE CYCLE DURING
WED. TIMING REMAINS AN ISSUE...AS ONE WOULD EXPECT THIS FAR OUT.
MODEL GUIDANCE STILL DOING A RATHER GOOD JOB HANDLING GENERAL
FEATURES OF THIS SYSTEM AT THIS POINT.

USED A BLEND OF THE AVAILABLE GUIDANCE ALONG WITH WPC GUIDANCE.

DETAILS...

SATURDAY INTO SUNDAY...HIGH CONFIDENCE.
HIGH PRES AT THE SURFACE AND ALOFT MOVES ACROSS QUEBEC INTO THE
MARITIMES DURING THIS WEEKEND...THEN TENDS TO SLOW ITS EASTWARD
PROGRESS WITH BLOCKING OVER THE WESTERN ATLC. RATHER POTENT SHORT
WAVE UNDERNEATH THE UPPER SYSTEM MOVES ACROSS THE REGION...AIDED
BY A LOW LEVEL E-NE WIND IN PLACE. A LOT OF LOW LEVEL MOISTURE IN
PLACE AS SEEN ON BUFKIT MODEL SOUNDINGS...SO WILL SEE SOME LIGHT
RAIN/SNOW SHOWERS DEVELOP FROM E-W DURING SATURDAY. EXPECTING
LITTLE IF ANY SNOW ACCUMULATIONS DURING SAT.

HOWEVER...AS TEMPS FALL BACK SAT NIGHT...ALONG WITH THE DEEP LOW
LEVEL MOISTURE FEED...WILL ALSO SEE AREAS OF DRIZZLE DEVELOP. BIG
PROBLEM WILL BE JUST AWAY FROM THE COAST WHERE TEMPS FALL BELOW
FREEZING WHICH MAY MEAN FREEZING DRIZZLE. DOES NOT TAKE MUCH TO
GET GLAZING ESPECIALLY ON UNTREATED SURFACES. WILL NEED TO MONITOR
THIS CLOSELY FOR POSSIBLE WINTER WEATHER HEADLINES ACROSS INTERIOR
E MA INTO RI...POSSIBLY EVEN FURTHER W. WITH THE LIGHT
SNOW...MIGHT SEE UP TO 1/2 INCH ACCUMULATIONS SAT NIGHT INTO SUN
MORNING.

ON SUNDAY...DRIZZLE WILL TAPER OFF DURING THE MORNING...THOUGH
LEFTOVER RAIN/SNOW SHOWERS WILL LINGER THOUGH TEND TO TAPER OFF
DURING THE AFTERNOON.

MONDAY INTO TUESDAY...MODERATE CONFIDENCE.
ANOTHER COASTAL LOW LOOKS TO DEVELOP OFF THE SE U.S. COAST
AND...AS UPPER LEVEL TROUGH BEGINS TO DIG ACROSS THE CENTRAL
U.S...WILL SHIFT TO THE E-NE UNDERNEATH THE UPPER RIDGE. THE
MARITIMES SURFACE HIGH REMAINS PRETTY MUCH IN PLACE...WHICH WILL
HELP SHIFT THE MAIN EFFECTS OF THIS LOW WELL OFFSHORE /SE OF THE
40N/70W BENCHMARK/. HOWEVER...MODELS CONTINUE TO SIGNAL LIGHT
PRECIP REACHING THE COAST MAINLY MON NIGHT INTO TUE. EXPECT MAINLY
MIXED RAIN/SNOW SHOWERS WITH SPOTTY BRIEF PERIODS OF FREEZING
PRECIP AROUND DAYBREAK TUE ACROSS N CT/N RI INTO S CENTRAL MA.
EXPECT HIGH TEMPS ON TUE TO RUN ABOUT 5 DEGS ABOVE SEASONAL NORMS
AS WINDS BEGIN TO SHIFT MORE S- SE...THOUGH SOME TIMING ISSUES IN
PLACE FOR WIND SHIFT AMONGST OP MODELS.

ONCE THE LOW EXITS LATE TUE...WILL ALREADY START TO SEE MOISTURE
FEED UP THE COAST FROM THE DEVELOPING GULF LOW...SO NOT MUCH OF A
BREAK IN THE PRECIP BETWEEN SYSTEMS.

TUESDAY/S LATE MORNING HIGH TIDE WILL RUN UP TO 11.6 FT IN BOSTON
AND...WITH ANY EASTERLY WIND FLOW...THIS MAY CAUSE MINOR COASTAL
FLOODING. WILL MONITOR THIS ASPECT.

WEDNESDAY AND CHRISTMAS DAY...HIGH CONFIDENCE IN SYSTEM...LOW
CONFIDENCE ON DETAILS.

SECONDARY LOW FROM THE PARENT OVER THE NORTHERN GREAT LAKES
DEEPENS AS IT SHIFTS N. MODELS TRY TO PUSH THIS SYSTEM CLOSE TO OR
JUST INTO WESTERN NEW ENGLAND LATE WED/WED NIGHT...THOUGH STILL
TIMING ISSUES IN PLACE. AT THIS POINT...WILL SEE HEAVIEST SLUG OF
PRECIP MOVING ACROSS LATE WED INTO WED EVENING. GOOD TROPICAL
CONNECTION CONTINUES WITH PWATS FROM 1.25 TO 1.4 INCHES...RUNNING
ABOUT +2SD TO +3SD ABOVE NORMAL FOR LATE DECEMBER. GOOD SHOT OF
MILD AIR WORKS IN ON SE-S WINDS. MODELS CONTINUE TO SIGNAL H925
AND H85 FROM 50-65 KT...AND AT LEAST SOME WILL MIX DOWN ESPECIALLY
IF THE LOW PRES PASSES CLOSER /WITH RAPIDLY FALLING PRESSURE/.
HAVE HIGHS ON WED UP TO THE LOWER 50S ACROSS EASTERN AND SOUTHERN
AREAS...BUT COULD BE EVEN HIGHER WITH STRONG ONSHORE WINDS.

CURRENT TIMING SUGGESTS THE DRY SLOT SHOULD WORK INTO THE REGION
LATE WED NIGHT INTO CHRISTMAS MORNING...SO PRECIP SHOULD END. WILL
STILL SEE GUSTY WINDS...THOUGH QUICKLY SHIFTING TO W-SW AND
GUSTING UP TO 25-30 KT...HIGHEST ALONG THE S COAST.

MAY NEED HEADLINES WITH THIS SYSTEM...WITH POSSIBLE URBAN/POOR
DRAINAGE FLOODING IN HEAVY RAINFALL WED/WED NIGHT...STRONG WINDS
BOTH WED AND THU...AND MAYBE EVEN FOR COASTAL CONCERNS. NOTING
ASTRO HIGH TIDES CONTINUE /11.7 AND 11.5 FT AT BOSTON
RESPECTIVELY/... THOUGH TIMING OF WIND SHIFT MAY COME INTO PLAY
FOR CHRISTMAS EVE INTO CHRISTMAS MORNING.

FRIDAY...LOW CONFIDENCE MAINLY FOR TIMING.
ONCE UPPER LOW MOVES INTO SOUTHERN CANADA...EXPECT A RATHER FAST
UPPER W FLOW IN PLACE. MAY SEE LEFTOVER SNOW SHOWERS ACROSS THE E
SLOPES OF THE BERKSHIRES INTO THE MONADNOCKS. TEMPS WILL FALL BACK
CLOSE TO SEASONAL NORMS. ANOTHER LOW MIGHT MOVE INTO W NY STATE
FRI NIGHT.

&&

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

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

SHORT TERM /TODAY THROUGH SATURDAY/...

TODAY AND TONIGHT...LOW TO MODERATE CONFIDENCE.  A BROKEN DECK OF
CLOUDS WILL PROBABLY REMAIN IN PLACE TODAY.  OVERALL...OUR
CONFIDENCE IN SKY COVER IS BELOW NORMAL BUT CEILINGS SHOULD VARY
BETWEEN LOW END VFR TO MVFR THROUGH THE AFTERNOON.  PERHAPS SOME OF
THE CLOUDS SCATTER OUT THIS EVENING...BUT AGAIN THAT IS UNCERTAIN.
OCEAN EFFECT CLOUDINESS WILL DEVELOP ACROSS THE CAPE/ACK AS WINDS
TURN TO A MORE NORTHERLY DIRECTION.

SATURDAY...MODERATE CONFIDENCE.  MVFR CIGS OVERSPREAD THE COASTAL
PLAIN AND EVENTUALLY EVEN INTO PORTIONS OF THE INTERIOR BY LATE
AFTERNOON.  SCATTERED OCEAN EFFECT LIGHT RAIN/SNOW SHOWERS WILL
OVERSPREAD THE SOUTHEAST NEW ENGLAND COAST WITH NORTHEAST SURFACE
WINDS.

OUTLOOK...SATURDAY NIGHT THROUGH TUESDAY...

SATURDAY NIGHT INTO SUNDAY...HIGH CONFIDENCE. MAINLY VFR ACROSS
CENTRAL AND WESTERN AREAS. E MA INTO RI...AREAS MVFR CIGS/VSBYS IN
ANY RAIN/SNOW SHOWERS...AREAS OF DRIZZLE SAT NIGHT INTO SUN MORNING.

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 FRIDAY NIGHT/...HIGH CONFIDENCE.

110 AM UPDATE...

OVERNIGHT...NW WINDS CONTINUE TO GRADUALLY DIMINISH AS PRESSURE
GRADIENT WEAKENS.  LET SCA HEADLINES EXPIRE FOR SOUNDS AND
BAYS...BUT THEY CONTINUE INTO THE MORNING FOR LEFT OVER SEAS.

FRIDAY...NW WINDS WILL BE BELOW SCA THRESHOLDS...BUT HAZARDOUS
SEAS WILL CONTINUE THROUGH THE MORNING OVER THE OUTER EASTERN
WATERS...BEFORE SUBSIDING BELOW SCA. WILL LIKELY NEED TO EXTEND
THE SCA FOR SEAS INTO FRI MORNING.

FRIDAY NIGHT...N/NW WINDS AND SEAS BELOW SCA.

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.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR
     ANZ250-254>256.

&&

$$
SYNOPSIS...KJC/EVT
NEAR TERM...FRANK
SHORT TERM...KJC
LONG TERM...EVT
AVIATION...FRANK/EVT
MARINE...FRANK/KJC/EVT




000
FXUS61 KBOX 190225
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
914 PM EST THU DEC 18 2014

.SYNOPSIS...
DRY AND SEASONABLE CONDITIONS WILL PREVAIL FRIDAY. AN UPPER LEVEL
DISTURBANCE AND MOIST NORTHEAST FLOW WILL BRING SOME LIGHT
PRECIPITATION SATURDAY INTO SUNDAY. LOW PRESSURE WILL LIKELY PASS
WELL SOUTH OF THE REGION TUESDAY...BUT STILL COULD BRING A PERIOD
OF LIGHT PRECIPITATION. A MUCH STRONGER STORM IS LIKELY TO BRING
HEAVY RAIN AND WIND TO SOUTHERN NEW ENGLAND WEDNESDAY INTO
WEDNESDAY EVENING. DRY BUT VERY WINDY CONDITIONS FOLLOW FOR
CHRISTMAS DAY.

&&

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

925 PM UPDATE...

CYCLONIC FLOW AROUND LOW PRESSURE ACROSS THE CANADIAN MARITIMES
WILL RESULT IN AN ABUNDANCE OF LOW CLOUDS ACROSS SOUTHERN NEW
ENGLAND OVERNIGHT.  WHILE THERE WILL BE BREAKS IN THE OVERCAST AT
TIMES...EXPECT CLOUDS TO DOMINATE.  PRESSURE GRADIENT WILL CONTINUE
TO GRADUALLY WEAKEN AS LOW LIFTS FURTHER NORTHEAST...BUT NOT ENOUGH
FOR WINDS TO DECOUPLE.  THEREFORE...AGREE WITH PREVIOUS FORECAST
THAT LOW TEMPS WILL BE ABOVE GUIDANCE NUMBERS.  BY DAYBREAK
FRI...LOW TEMPS SHOULD BOTTOM OUT IN THE 20S TO THE LOWER 30S.


&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
FRIDAY...
HIGH PRES BUILDS ACROSS THE GRT LAKES WITH NW FLOW ACROSS NEW
ENG. TRICKY CLOUD FORECAST AS NAM INDICATING LOW LEVEL MOISTURE
TRAPPED BELOW INVERSION WITH WIDESPREAD LOW CLOUDS...WHILE GFS AND
ECMWF ARE DRIER IN THE LOW LEVELS. GIVEN LOW LEVEL FLOW IS STILL
NW...WE WILL LEAN MORE OPTIMISTIC THAN NAM WITH A MIX OF CLOUDS
AND SUN EXPECTED. TEMPS WILL LIKELY BE 3-5 DEGREES COLDER THAN
TODAY GIVEN COOLING AT 925 MB...WITH MAX TEMPS RANGING FROM NEAR
30 HIGHER TERRAIN IN NORTHERN AND WESTERN MA TO UPPER 30S IN THE
COASTAL PLAIN.

FRIDAY NIGHT...
MID LEVEL SHORTWAVE MOVES INTO W NEW ENG TOWARD DAYBREAK...BUT
FORCING IS WEAK THROUGH MOST OF THE NIGHT AND MOISTURE IS LIMITED
SO EXPECTING A MAINLY DRY NIGHT. HOWEVER...AS HIGH PRES BUILDS
EASTWARD ACROSS QUEBEC LOW LEVEL WINDS BECOME NE AND MODELS
INDICATE INCREASING LOW MOISTURE BACKING IN ACROSS SE NEW ENG
OVERNIGHT. DELTA T FROM SST TO THE TOP OF THE MIXED LAYER IS
AROUND 13C WHICH IS MARGINAL FOR OCEAN EFFECT AND OCEAN INDUCED
CAPES ARE NOT IMPRESSIVE...BUT LOW LEVEL LAPSE RATES ARE
INCREASING. MODELS DO SHOW SOME LIGHT QPF DEVELOPING SO THERE MAY
BE A FEW SNOW SHOWERS DEVELOPING OVER CAPE COD AND ACK OVERNIGHT
AND WE HAVE SOME LOW CHC POPS.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
HIGHLIGHTS...

* SCT LIGHT SNOW/RAIN SHOWERS SAT INTO SUN...WITH A PERIOD OF
  DRIZZLE/FREEZING DRIZZLE POSSIBLE SAT NIGHT INTO SUN MORNING
* WEAK WAVE OF LOW PRESSURE WILL PASS WELL OFFSHORE TUE BUT COULD
  STILL SEE LIGHT PRECIP
* ANOMALOUSLY STRONG STORM SYSTEM WILL BRING HEAVY RAIN...GUSTY
  WINDS AND COASTAL CONCERNS AROUND CHRISTMAS EVE

OVERVIEW AND MODEL PREFERENCES...
MEDIUM RANGE MODELS CONTINUE IN PRETTY GOOD AGREEMENT ON LARGE
SCALE AND UPPER LEVEL FEATURES THROUGH MOST OF THE FORECAST
PERIOD.

MODELS AND ENSEMBLES CONTINUE TO SIGNAL WEAK SHORT WAVES THAT
TRANSLATE ACROSS THE REGION EARLY IN THIS PERIOD...WITH A RATHER
POTENT BUT FAST MOVING ONE FOR SAT NIGHT/SUN TIMEFRAME WHICH IS
AIDED WITH LOW LEVEL ONSHORE MOISTURE...WITH A SECOND WEAK LOW FOR
LATE MON INTO TUE BRINGING ANOTHER PERIOD OF LIGHT PRECIP.

STILL QUITE A FEW PLACEMENT AND TIMING ISSUES WITH THE EVOLUTION
OF AN ANOMALOUSLY DEEP H5 CUTOFF LOW DEVELOPING ACROSS THE WESTERN
GREAT LAKES AROUND THE MON-TUE TIMEFRAME...THEN ROTATES NE
SOMEWHERE ACROSS S CENTRAL CANADA ON CHRISTMAS DAY. BIG
IMPLICATIONS WITH THE ASSOCIATED LONG WAVE TROUGH. GUIDANCE
CONTINUES TO INDICATE THE TROUGH BECOMING NEGATIVELY TILTED ACROSS
THE MID ATLC OR SE U.S. LATE IN THIS PERIOD. SECONDARY/ TRIPLE
POINT LOW FORMS ON SURFACE FRONT OVER THE EASTERN GULF AROUND
TUESDAY...THEN WORKS UP ACROSS EASTERN PORTIONS OF THE SE AND MID
ATLC STATES. QUESTION IS IF THIS LOW APPROACHES WESTERN PORTIONS
OF NEW ENGLAND WED NIGHT.

STILL SEE THE SIGNALS FOR A FAST MOVING STORM WITH MULTIPLE
IMPACTS POSSIBLE...INCLUDING PERIOD OF HEAVY RAINFALL AND STRONG
WIND GUSTS...FIRST FROM THE SOUTH THEN SHIFTING TO THE WEST. COULD
EVEN SEE SOME COASTAL IMPACTS DURING THE HIGH TIDE CYCLE DURING
WED. TIMING REMAINS AN ISSUE...AS ONE WOULD EXPECT THIS FAR OUT.
MODEL GUIDANCE STILL DOING A RATHER GOOD JOB HANDLING GENERAL
FEATURES OF THIS SYSTEM AT THIS POINT.

USED A BLEND OF THE AVAILABLE GUIDANCE ALONG WITH WPC GUIDANCE.

DETAILS...

SATURDAY INTO SUNDAY...HIGH CONFIDENCE.
HIGH PRES AT THE SURFACE AND ALOFT MOVES ACROSS QUEBEC INTO THE
MARITIMES DURING THIS WEEKEND...THEN TENDS TO SLOW ITS EASTWARD
PROGRESS WITH BLOCKING OVER THE WESTERN ATLC. RATHER POTENT SHORT
WAVE UNDERNEATH THE UPPER SYSTEM MOVES ACROSS THE REGION...AIDED
BY A LOW LEVEL E-NE WIND IN PLACE. A LOT OF LOW LEVEL MOISTURE IN
PLACE AS SEEN ON BUFKIT MODEL SOUNDINGS...SO WILL SEE SOME LIGHT
RAIN/SNOW SHOWERS DEVELOP FROM E-W DURING SATURDAY. EXPECTING
LITTLE IF ANY SNOW ACCUMULATIONS DURING SAT.

HOWEVER...AS TEMPS FALL BACK SAT NIGHT...ALONG WITH THE DEEP LOW
LEVEL MOISTURE FEED...WILL ALSO SEE AREAS OF DRIZZLE DEVELOP. BIG
PROBLEM WILL BE JUST AWAY FROM THE COAST WHERE TEMPS FALL BELOW
FREEZING WHICH MAY MEAN FREEZING DRIZZLE. DOES NOT TAKE MUCH TO
GET GLAZING ESPECIALLY ON UNTREATED SURFACES. WILL NEED TO MONITOR
THIS CLOSELY FOR POSSIBLE WINTER WEATHER HEADLINES ACROSS INTERIOR
E MA INTO RI...POSSIBLY EVEN FURTHER W. WITH THE LIGHT
SNOW...MIGHT SEE UP TO 1/2 INCH ACCUMULATIONS SAT NIGHT INTO SUN
MORNING.

ON SUNDAY...DRIZZLE WILL TAPER OFF DURING THE MORNING...THOUGH
LEFTOVER RAIN/SNOW SHOWERS WILL LINGER THOUGH TEND TO TAPER OFF
DURING THE AFTERNOON.

MONDAY INTO TUESDAY...MODERATE CONFIDENCE.
ANOTHER COASTAL LOW LOOKS TO DEVELOP OFF THE SE U.S. COAST
AND...AS UPPER LEVEL TROUGH BEGINS TO DIG ACROSS THE CENTRAL
U.S...WILL SHIFT TO THE E-NE UNDERNEATH THE UPPER RIDGE. THE
MARITIMES SURFACE HIGH REMAINS PRETTY MUCH IN PLACE...WHICH WILL
HELP SHIFT THE MAIN EFFECTS OF THIS LOW WELL OFFSHORE /SE OF THE
40N/70W BENCHMARK/. HOWEVER...MODELS CONTINUE TO SIGNAL LIGHT
PRECIP REACHING THE COAST MAINLY MON NIGHT INTO TUE. EXPECT MAINLY
MIXED RAIN/SNOW SHOWERS WITH SPOTTY BRIEF PERIODS OF FREEZING
PRECIP AROUND DAYBREAK TUE ACROSS N CT/N RI INTO S CENTRAL MA.
EXPECT HIGH TEMPS ON TUE TO RUN ABOUT 5 DEGS ABOVE SEASONAL NORMS
AS WINDS BEGIN TO SHIFT MORE S- SE...THOUGH SOME TIMING ISSUES IN
PLACE FOR WIND SHIFT AMONGST OP MODELS.

ONCE THE LOW EXITS LATE TUE...WILL ALREADY START TO SEE MOISTURE
FEED UP THE COAST FROM THE DEVELOPING GULF LOW...SO NOT MUCH OF A
BREAK IN THE PRECIP BETWEEN SYSTEMS.

TUESDAY/S LATE MORNING HIGH TIDE WILL RUN UP TO 11.6 FT IN BOSTON
AND...WITH ANY EASTERLY WIND FLOW...THIS MAY CAUSE MINOR COASTAL
FLOODING. WILL MONITOR THIS ASPECT.

WEDNESDAY AND CHRISTMAS DAY...HIGH CONFIDENCE IN SYSTEM...LOW
CONFIDENCE ON DETAILS.

SECONDARY LOW FROM THE PARENT OVER THE NORTHERN GREAT LAKES
DEEPENS AS IT SHIFTS N. MODELS TRY TO PUSH THIS SYSTEM CLOSE TO OR
JUST INTO WESTERN NEW ENGLAND LATE WED/WED NIGHT...THOUGH STILL
TIMING ISSUES IN PLACE. AT THIS POINT...WILL SEE HEAVIEST SLUG OF
PRECIP MOVING ACROSS LATE WED INTO WED EVENING. GOOD TROPICAL
CONNECTION CONTINUES WITH PWATS FROM 1.25 TO 1.4 INCHES...RUNNING
ABOUT +2SD TO +3SD ABOVE NORMAL FOR LATE DECEMBER. GOOD SHOT OF
MILD AIR WORKS IN ON SE-S WINDS. MODELS CONTINUE TO SIGNAL H925
AND H85 FROM 50-65 KT...AND AT LEAST SOME WILL MIX DOWN ESPECIALLY
IF THE LOW PRES PASSES CLOSER /WITH RAPIDLY FALLING PRESSURE/.
HAVE HIGHS ON WED UP TO THE LOWER 50S ACROSS EASTERN AND SOUTHERN
AREAS...BUT COULD BE EVEN HIGHER WITH STRONG ONSHORE WINDS.

CURRENT TIMING SUGGESTS THE DRY SLOT SHOULD WORK INTO THE REGION
LATE WED NIGHT INTO CHRISTMAS MORNING...SO PRECIP SHOULD END. WILL
STILL SEE GUSTY WINDS...THOUGH QUICKLY SHIFTING TO W-SW AND
GUSTING UP TO 25-30 KT...HIGHEST ALONG THE S COAST.

MAY NEED HEADLINES WITH THIS SYSTEM...WITH POSSIBLE URBAN/POOR
DRAINAGE FLOODING IN HEAVY RAINFALL WED/WED NIGHT...STRONG WINDS
BOTH WED AND THU...AND MAYBE EVEN FOR COASTAL CONCERNS. NOTING
ASTRO HIGH TIDES CONTINUE /11.7 AND 11.5 FT AT BOSTON
RESPECTIVELY/... THOUGH TIMING OF WIND SHIFT MAY COME INTO PLAY
FOR CHRISTMAS EVE INTO CHRISTMAS MORNING.

FRIDAY...LOW CONFIDENCE MAINLY FOR TIMING.
ONCE UPPER LOW MOVES INTO SOUTHERN CANADA...EXPECT A RATHER FAST
UPPER W FLOW IN PLACE. MAY SEE LEFTOVER SNOW SHOWERS ACROSS THE E
SLOPES OF THE BERKSHIRES INTO THE MONADNOCKS. TEMPS WILL FALL BACK
CLOSE TO SEASONAL NORMS. ANOTHER LOW MIGHT MOVE INTO W NY STATE
FRI NIGHT.

&&

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

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

SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...

925 PM UPDATE...

OVERNIGHT...MODERATE CONFIDENCE.  A BROKEN DECK OF CLOUDS BETWEEN 2
AND 4 THOUSAND FEET ACROSS MOST OF THE REGION WILL PERSIST.
THEREFORE...EXPECT CONDITIONS TO VARY BETWEEN LOW END VFR AND MVFR.
THE LOWER CIGS WILL TEND TO BE FOUND ACROSS THE INTERIOR.

FRIDAY...LOW CONFIDENCE DUE TO UNCERTAINTY WITH EXTENT OF ANY MVFR
CIGS. WE HAVE MAINLY VFR IN THE TAFS WITH POCKETS OF MVFR...BUT
IT IS POSSIBLE MVFR CIGS COULD BE MORE EXPANSIVE IF LOW LEVEL
MOISTURE BECOMES TRAPPED BELOW THE INVERSION. LATER FORECASTS
WILL NEED TO REEVALUATE THIS.

FRIDAY NIGHT...MODERATE CONFIDENCE. MAINLY VFR...BUT MVFR CIGS
FROM THE OCEAN EXPANDING WEST ACROSS E MA. LOW PROB FOR SOME OCEAN
EFFECT SNOW SHOWERS OVER CAPE COD AND ACK AFTER MIDNIGHT.

KBOS TERMINAL...MODERATE CONFIDENCE. BROKEN DECK OF CLOUDS BETWEEN
2500 AND 4000 FEET INTO EARLY FRI MORNING.

KBDL TERMINAL...MODERATE CONFIDENCE. BROKEN DECK OF CLOUDS BETWEEN
2500 AND 4000 FEET INTO EARLY FRI MORNING

OUTLOOK...SATURDAY THROUGH TUESDAY...

SATURDAY INTO SUNDAY...HIGH CONFIDENCE. MAINLY VFR ACROSS CENTRAL
AND WESTERN AREAS. E MA INTO RI...AREAS MVFR CIGS/VSBYS IN ANY
RAIN/SNOW SHOWERS...AREAS OF DRIZZLE SAT NIGHT INTO SUN MORNING.

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 FRIDAY NIGHT/...HIGH CONFIDENCE.

925 PM UPDATE...

OVERNIGHT...W/NW GUSTS AROUND 25 KNOTS WILL CONTINUE TO GRADUALLY
DIMINISH OVERNIGHT. SCA HEADLINES WILL EXPIRE FOR THE NEAR SHORE
OPEN WATERS TOWARD DAYBREAK...BUT REMAIN ACROSS THE OUTER-WATERS
INTO FRIDAY MORNING FOR LEFT OVER SEAS.

FRIDAY...NW WINDS WILL BE BELOW SCA THRESHOLDS...BUT HAZARDOUS
SEAS WILL CONTINUE THROUGH THE MORNING OVER THE OUTER EASTERN
WATERS...BEFORE SUBSIDING BELOW SCA. WILL LIKELY NEED TO EXTEND
THE SCA FOR SEAS INTO FRI MORNING.

FRIDAY NIGHT...N/NW WINDS AND SEAS BELOW SCA.

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.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 AM EST FRIDAY FOR ANZ231-232-235-
     237-251.
     SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ250-254>256.

&&

$$
SYNOPSIS...KJC/EVT
NEAR TERM...FRANK
SHORT TERM...KJC
LONG TERM...EVT
AVIATION...FRANK/KJC/EVT
MARINE...FRANK/KJC/EVT



000
FXUS61 KBOX 190225
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
914 PM EST THU DEC 18 2014

.SYNOPSIS...
DRY AND SEASONABLE CONDITIONS WILL PREVAIL FRIDAY. AN UPPER LEVEL
DISTURBANCE AND MOIST NORTHEAST FLOW WILL BRING SOME LIGHT
PRECIPITATION SATURDAY INTO SUNDAY. LOW PRESSURE WILL LIKELY PASS
WELL SOUTH OF THE REGION TUESDAY...BUT STILL COULD BRING A PERIOD
OF LIGHT PRECIPITATION. A MUCH STRONGER STORM IS LIKELY TO BRING
HEAVY RAIN AND WIND TO SOUTHERN NEW ENGLAND WEDNESDAY INTO
WEDNESDAY EVENING. DRY BUT VERY WINDY CONDITIONS FOLLOW FOR
CHRISTMAS DAY.

&&

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

925 PM UPDATE...

CYCLONIC FLOW AROUND LOW PRESSURE ACROSS THE CANADIAN MARITIMES
WILL RESULT IN AN ABUNDANCE OF LOW CLOUDS ACROSS SOUTHERN NEW
ENGLAND OVERNIGHT.  WHILE THERE WILL BE BREAKS IN THE OVERCAST AT
TIMES...EXPECT CLOUDS TO DOMINATE.  PRESSURE GRADIENT WILL CONTINUE
TO GRADUALLY WEAKEN AS LOW LIFTS FURTHER NORTHEAST...BUT NOT ENOUGH
FOR WINDS TO DECOUPLE.  THEREFORE...AGREE WITH PREVIOUS FORECAST
THAT LOW TEMPS WILL BE ABOVE GUIDANCE NUMBERS.  BY DAYBREAK
FRI...LOW TEMPS SHOULD BOTTOM OUT IN THE 20S TO THE LOWER 30S.


&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
FRIDAY...
HIGH PRES BUILDS ACROSS THE GRT LAKES WITH NW FLOW ACROSS NEW
ENG. TRICKY CLOUD FORECAST AS NAM INDICATING LOW LEVEL MOISTURE
TRAPPED BELOW INVERSION WITH WIDESPREAD LOW CLOUDS...WHILE GFS AND
ECMWF ARE DRIER IN THE LOW LEVELS. GIVEN LOW LEVEL FLOW IS STILL
NW...WE WILL LEAN MORE OPTIMISTIC THAN NAM WITH A MIX OF CLOUDS
AND SUN EXPECTED. TEMPS WILL LIKELY BE 3-5 DEGREES COLDER THAN
TODAY GIVEN COOLING AT 925 MB...WITH MAX TEMPS RANGING FROM NEAR
30 HIGHER TERRAIN IN NORTHERN AND WESTERN MA TO UPPER 30S IN THE
COASTAL PLAIN.

FRIDAY NIGHT...
MID LEVEL SHORTWAVE MOVES INTO W NEW ENG TOWARD DAYBREAK...BUT
FORCING IS WEAK THROUGH MOST OF THE NIGHT AND MOISTURE IS LIMITED
SO EXPECTING A MAINLY DRY NIGHT. HOWEVER...AS HIGH PRES BUILDS
EASTWARD ACROSS QUEBEC LOW LEVEL WINDS BECOME NE AND MODELS
INDICATE INCREASING LOW MOISTURE BACKING IN ACROSS SE NEW ENG
OVERNIGHT. DELTA T FROM SST TO THE TOP OF THE MIXED LAYER IS
AROUND 13C WHICH IS MARGINAL FOR OCEAN EFFECT AND OCEAN INDUCED
CAPES ARE NOT IMPRESSIVE...BUT LOW LEVEL LAPSE RATES ARE
INCREASING. MODELS DO SHOW SOME LIGHT QPF DEVELOPING SO THERE MAY
BE A FEW SNOW SHOWERS DEVELOPING OVER CAPE COD AND ACK OVERNIGHT
AND WE HAVE SOME LOW CHC POPS.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
HIGHLIGHTS...

* SCT LIGHT SNOW/RAIN SHOWERS SAT INTO SUN...WITH A PERIOD OF
  DRIZZLE/FREEZING DRIZZLE POSSIBLE SAT NIGHT INTO SUN MORNING
* WEAK WAVE OF LOW PRESSURE WILL PASS WELL OFFSHORE TUE BUT COULD
  STILL SEE LIGHT PRECIP
* ANOMALOUSLY STRONG STORM SYSTEM WILL BRING HEAVY RAIN...GUSTY
  WINDS AND COASTAL CONCERNS AROUND CHRISTMAS EVE

OVERVIEW AND MODEL PREFERENCES...
MEDIUM RANGE MODELS CONTINUE IN PRETTY GOOD AGREEMENT ON LARGE
SCALE AND UPPER LEVEL FEATURES THROUGH MOST OF THE FORECAST
PERIOD.

MODELS AND ENSEMBLES CONTINUE TO SIGNAL WEAK SHORT WAVES THAT
TRANSLATE ACROSS THE REGION EARLY IN THIS PERIOD...WITH A RATHER
POTENT BUT FAST MOVING ONE FOR SAT NIGHT/SUN TIMEFRAME WHICH IS
AIDED WITH LOW LEVEL ONSHORE MOISTURE...WITH A SECOND WEAK LOW FOR
LATE MON INTO TUE BRINGING ANOTHER PERIOD OF LIGHT PRECIP.

STILL QUITE A FEW PLACEMENT AND TIMING ISSUES WITH THE EVOLUTION
OF AN ANOMALOUSLY DEEP H5 CUTOFF LOW DEVELOPING ACROSS THE WESTERN
GREAT LAKES AROUND THE MON-TUE TIMEFRAME...THEN ROTATES NE
SOMEWHERE ACROSS S CENTRAL CANADA ON CHRISTMAS DAY. BIG
IMPLICATIONS WITH THE ASSOCIATED LONG WAVE TROUGH. GUIDANCE
CONTINUES TO INDICATE THE TROUGH BECOMING NEGATIVELY TILTED ACROSS
THE MID ATLC OR SE U.S. LATE IN THIS PERIOD. SECONDARY/ TRIPLE
POINT LOW FORMS ON SURFACE FRONT OVER THE EASTERN GULF AROUND
TUESDAY...THEN WORKS UP ACROSS EASTERN PORTIONS OF THE SE AND MID
ATLC STATES. QUESTION IS IF THIS LOW APPROACHES WESTERN PORTIONS
OF NEW ENGLAND WED NIGHT.

STILL SEE THE SIGNALS FOR A FAST MOVING STORM WITH MULTIPLE
IMPACTS POSSIBLE...INCLUDING PERIOD OF HEAVY RAINFALL AND STRONG
WIND GUSTS...FIRST FROM THE SOUTH THEN SHIFTING TO THE WEST. COULD
EVEN SEE SOME COASTAL IMPACTS DURING THE HIGH TIDE CYCLE DURING
WED. TIMING REMAINS AN ISSUE...AS ONE WOULD EXPECT THIS FAR OUT.
MODEL GUIDANCE STILL DOING A RATHER GOOD JOB HANDLING GENERAL
FEATURES OF THIS SYSTEM AT THIS POINT.

USED A BLEND OF THE AVAILABLE GUIDANCE ALONG WITH WPC GUIDANCE.

DETAILS...

SATURDAY INTO SUNDAY...HIGH CONFIDENCE.
HIGH PRES AT THE SURFACE AND ALOFT MOVES ACROSS QUEBEC INTO THE
MARITIMES DURING THIS WEEKEND...THEN TENDS TO SLOW ITS EASTWARD
PROGRESS WITH BLOCKING OVER THE WESTERN ATLC. RATHER POTENT SHORT
WAVE UNDERNEATH THE UPPER SYSTEM MOVES ACROSS THE REGION...AIDED
BY A LOW LEVEL E-NE WIND IN PLACE. A LOT OF LOW LEVEL MOISTURE IN
PLACE AS SEEN ON BUFKIT MODEL SOUNDINGS...SO WILL SEE SOME LIGHT
RAIN/SNOW SHOWERS DEVELOP FROM E-W DURING SATURDAY. EXPECTING
LITTLE IF ANY SNOW ACCUMULATIONS DURING SAT.

HOWEVER...AS TEMPS FALL BACK SAT NIGHT...ALONG WITH THE DEEP LOW
LEVEL MOISTURE FEED...WILL ALSO SEE AREAS OF DRIZZLE DEVELOP. BIG
PROBLEM WILL BE JUST AWAY FROM THE COAST WHERE TEMPS FALL BELOW
FREEZING WHICH MAY MEAN FREEZING DRIZZLE. DOES NOT TAKE MUCH TO
GET GLAZING ESPECIALLY ON UNTREATED SURFACES. WILL NEED TO MONITOR
THIS CLOSELY FOR POSSIBLE WINTER WEATHER HEADLINES ACROSS INTERIOR
E MA INTO RI...POSSIBLY EVEN FURTHER W. WITH THE LIGHT
SNOW...MIGHT SEE UP TO 1/2 INCH ACCUMULATIONS SAT NIGHT INTO SUN
MORNING.

ON SUNDAY...DRIZZLE WILL TAPER OFF DURING THE MORNING...THOUGH
LEFTOVER RAIN/SNOW SHOWERS WILL LINGER THOUGH TEND TO TAPER OFF
DURING THE AFTERNOON.

MONDAY INTO TUESDAY...MODERATE CONFIDENCE.
ANOTHER COASTAL LOW LOOKS TO DEVELOP OFF THE SE U.S. COAST
AND...AS UPPER LEVEL TROUGH BEGINS TO DIG ACROSS THE CENTRAL
U.S...WILL SHIFT TO THE E-NE UNDERNEATH THE UPPER RIDGE. THE
MARITIMES SURFACE HIGH REMAINS PRETTY MUCH IN PLACE...WHICH WILL
HELP SHIFT THE MAIN EFFECTS OF THIS LOW WELL OFFSHORE /SE OF THE
40N/70W BENCHMARK/. HOWEVER...MODELS CONTINUE TO SIGNAL LIGHT
PRECIP REACHING THE COAST MAINLY MON NIGHT INTO TUE. EXPECT MAINLY
MIXED RAIN/SNOW SHOWERS WITH SPOTTY BRIEF PERIODS OF FREEZING
PRECIP AROUND DAYBREAK TUE ACROSS N CT/N RI INTO S CENTRAL MA.
EXPECT HIGH TEMPS ON TUE TO RUN ABOUT 5 DEGS ABOVE SEASONAL NORMS
AS WINDS BEGIN TO SHIFT MORE S- SE...THOUGH SOME TIMING ISSUES IN
PLACE FOR WIND SHIFT AMONGST OP MODELS.

ONCE THE LOW EXITS LATE TUE...WILL ALREADY START TO SEE MOISTURE
FEED UP THE COAST FROM THE DEVELOPING GULF LOW...SO NOT MUCH OF A
BREAK IN THE PRECIP BETWEEN SYSTEMS.

TUESDAY/S LATE MORNING HIGH TIDE WILL RUN UP TO 11.6 FT IN BOSTON
AND...WITH ANY EASTERLY WIND FLOW...THIS MAY CAUSE MINOR COASTAL
FLOODING. WILL MONITOR THIS ASPECT.

WEDNESDAY AND CHRISTMAS DAY...HIGH CONFIDENCE IN SYSTEM...LOW
CONFIDENCE ON DETAILS.

SECONDARY LOW FROM THE PARENT OVER THE NORTHERN GREAT LAKES
DEEPENS AS IT SHIFTS N. MODELS TRY TO PUSH THIS SYSTEM CLOSE TO OR
JUST INTO WESTERN NEW ENGLAND LATE WED/WED NIGHT...THOUGH STILL
TIMING ISSUES IN PLACE. AT THIS POINT...WILL SEE HEAVIEST SLUG OF
PRECIP MOVING ACROSS LATE WED INTO WED EVENING. GOOD TROPICAL
CONNECTION CONTINUES WITH PWATS FROM 1.25 TO 1.4 INCHES...RUNNING
ABOUT +2SD TO +3SD ABOVE NORMAL FOR LATE DECEMBER. GOOD SHOT OF
MILD AIR WORKS IN ON SE-S WINDS. MODELS CONTINUE TO SIGNAL H925
AND H85 FROM 50-65 KT...AND AT LEAST SOME WILL MIX DOWN ESPECIALLY
IF THE LOW PRES PASSES CLOSER /WITH RAPIDLY FALLING PRESSURE/.
HAVE HIGHS ON WED UP TO THE LOWER 50S ACROSS EASTERN AND SOUTHERN
AREAS...BUT COULD BE EVEN HIGHER WITH STRONG ONSHORE WINDS.

CURRENT TIMING SUGGESTS THE DRY SLOT SHOULD WORK INTO THE REGION
LATE WED NIGHT INTO CHRISTMAS MORNING...SO PRECIP SHOULD END. WILL
STILL SEE GUSTY WINDS...THOUGH QUICKLY SHIFTING TO W-SW AND
GUSTING UP TO 25-30 KT...HIGHEST ALONG THE S COAST.

MAY NEED HEADLINES WITH THIS SYSTEM...WITH POSSIBLE URBAN/POOR
DRAINAGE FLOODING IN HEAVY RAINFALL WED/WED NIGHT...STRONG WINDS
BOTH WED AND THU...AND MAYBE EVEN FOR COASTAL CONCERNS. NOTING
ASTRO HIGH TIDES CONTINUE /11.7 AND 11.5 FT AT BOSTON
RESPECTIVELY/... THOUGH TIMING OF WIND SHIFT MAY COME INTO PLAY
FOR CHRISTMAS EVE INTO CHRISTMAS MORNING.

FRIDAY...LOW CONFIDENCE MAINLY FOR TIMING.
ONCE UPPER LOW MOVES INTO SOUTHERN CANADA...EXPECT A RATHER FAST
UPPER W FLOW IN PLACE. MAY SEE LEFTOVER SNOW SHOWERS ACROSS THE E
SLOPES OF THE BERKSHIRES INTO THE MONADNOCKS. TEMPS WILL FALL BACK
CLOSE TO SEASONAL NORMS. ANOTHER LOW MIGHT MOVE INTO W NY STATE
FRI NIGHT.

&&

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

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

SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...

925 PM UPDATE...

OVERNIGHT...MODERATE CONFIDENCE.  A BROKEN DECK OF CLOUDS BETWEEN 2
AND 4 THOUSAND FEET ACROSS MOST OF THE REGION WILL PERSIST.
THEREFORE...EXPECT CONDITIONS TO VARY BETWEEN LOW END VFR AND MVFR.
THE LOWER CIGS WILL TEND TO BE FOUND ACROSS THE INTERIOR.

FRIDAY...LOW CONFIDENCE DUE TO UNCERTAINTY WITH EXTENT OF ANY MVFR
CIGS. WE HAVE MAINLY VFR IN THE TAFS WITH POCKETS OF MVFR...BUT
IT IS POSSIBLE MVFR CIGS COULD BE MORE EXPANSIVE IF LOW LEVEL
MOISTURE BECOMES TRAPPED BELOW THE INVERSION. LATER FORECASTS
WILL NEED TO REEVALUATE THIS.

FRIDAY NIGHT...MODERATE CONFIDENCE. MAINLY VFR...BUT MVFR CIGS
FROM THE OCEAN EXPANDING WEST ACROSS E MA. LOW PROB FOR SOME OCEAN
EFFECT SNOW SHOWERS OVER CAPE COD AND ACK AFTER MIDNIGHT.

KBOS TERMINAL...MODERATE CONFIDENCE. BROKEN DECK OF CLOUDS BETWEEN
2500 AND 4000 FEET INTO EARLY FRI MORNING.

KBDL TERMINAL...MODERATE CONFIDENCE. BROKEN DECK OF CLOUDS BETWEEN
2500 AND 4000 FEET INTO EARLY FRI MORNING

OUTLOOK...SATURDAY THROUGH TUESDAY...

SATURDAY INTO SUNDAY...HIGH CONFIDENCE. MAINLY VFR ACROSS CENTRAL
AND WESTERN AREAS. E MA INTO RI...AREAS MVFR CIGS/VSBYS IN ANY
RAIN/SNOW SHOWERS...AREAS OF DRIZZLE SAT NIGHT INTO SUN MORNING.

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 FRIDAY NIGHT/...HIGH CONFIDENCE.

925 PM UPDATE...

OVERNIGHT...W/NW GUSTS AROUND 25 KNOTS WILL CONTINUE TO GRADUALLY
DIMINISH OVERNIGHT. SCA HEADLINES WILL EXPIRE FOR THE NEAR SHORE
OPEN WATERS TOWARD DAYBREAK...BUT REMAIN ACROSS THE OUTER-WATERS
INTO FRIDAY MORNING FOR LEFT OVER SEAS.

FRIDAY...NW WINDS WILL BE BELOW SCA THRESHOLDS...BUT HAZARDOUS
SEAS WILL CONTINUE THROUGH THE MORNING OVER THE OUTER EASTERN
WATERS...BEFORE SUBSIDING BELOW SCA. WILL LIKELY NEED TO EXTEND
THE SCA FOR SEAS INTO FRI MORNING.

FRIDAY NIGHT...N/NW WINDS AND SEAS BELOW SCA.

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.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 AM EST FRIDAY FOR ANZ231-232-235-
     237-251.
     SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ250-254>256.

&&

$$
SYNOPSIS...KJC/EVT
NEAR TERM...FRANK
SHORT TERM...KJC
LONG TERM...EVT
AVIATION...FRANK/KJC/EVT
MARINE...FRANK/KJC/EVT



000
FXUS61 KBOX 190225
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
914 PM EST THU DEC 18 2014

.SYNOPSIS...
DRY AND SEASONABLE CONDITIONS WILL PREVAIL FRIDAY. AN UPPER LEVEL
DISTURBANCE AND MOIST NORTHEAST FLOW WILL BRING SOME LIGHT
PRECIPITATION SATURDAY INTO SUNDAY. LOW PRESSURE WILL LIKELY PASS
WELL SOUTH OF THE REGION TUESDAY...BUT STILL COULD BRING A PERIOD
OF LIGHT PRECIPITATION. A MUCH STRONGER STORM IS LIKELY TO BRING
HEAVY RAIN AND WIND TO SOUTHERN NEW ENGLAND WEDNESDAY INTO
WEDNESDAY EVENING. DRY BUT VERY WINDY CONDITIONS FOLLOW FOR
CHRISTMAS DAY.

&&

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

925 PM UPDATE...

CYCLONIC FLOW AROUND LOW PRESSURE ACROSS THE CANADIAN MARITIMES
WILL RESULT IN AN ABUNDANCE OF LOW CLOUDS ACROSS SOUTHERN NEW
ENGLAND OVERNIGHT.  WHILE THERE WILL BE BREAKS IN THE OVERCAST AT
TIMES...EXPECT CLOUDS TO DOMINATE.  PRESSURE GRADIENT WILL CONTINUE
TO GRADUALLY WEAKEN AS LOW LIFTS FURTHER NORTHEAST...BUT NOT ENOUGH
FOR WINDS TO DECOUPLE.  THEREFORE...AGREE WITH PREVIOUS FORECAST
THAT LOW TEMPS WILL BE ABOVE GUIDANCE NUMBERS.  BY DAYBREAK
FRI...LOW TEMPS SHOULD BOTTOM OUT IN THE 20S TO THE LOWER 30S.


&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
FRIDAY...
HIGH PRES BUILDS ACROSS THE GRT LAKES WITH NW FLOW ACROSS NEW
ENG. TRICKY CLOUD FORECAST AS NAM INDICATING LOW LEVEL MOISTURE
TRAPPED BELOW INVERSION WITH WIDESPREAD LOW CLOUDS...WHILE GFS AND
ECMWF ARE DRIER IN THE LOW LEVELS. GIVEN LOW LEVEL FLOW IS STILL
NW...WE WILL LEAN MORE OPTIMISTIC THAN NAM WITH A MIX OF CLOUDS
AND SUN EXPECTED. TEMPS WILL LIKELY BE 3-5 DEGREES COLDER THAN
TODAY GIVEN COOLING AT 925 MB...WITH MAX TEMPS RANGING FROM NEAR
30 HIGHER TERRAIN IN NORTHERN AND WESTERN MA TO UPPER 30S IN THE
COASTAL PLAIN.

FRIDAY NIGHT...
MID LEVEL SHORTWAVE MOVES INTO W NEW ENG TOWARD DAYBREAK...BUT
FORCING IS WEAK THROUGH MOST OF THE NIGHT AND MOISTURE IS LIMITED
SO EXPECTING A MAINLY DRY NIGHT. HOWEVER...AS HIGH PRES BUILDS
EASTWARD ACROSS QUEBEC LOW LEVEL WINDS BECOME NE AND MODELS
INDICATE INCREASING LOW MOISTURE BACKING IN ACROSS SE NEW ENG
OVERNIGHT. DELTA T FROM SST TO THE TOP OF THE MIXED LAYER IS
AROUND 13C WHICH IS MARGINAL FOR OCEAN EFFECT AND OCEAN INDUCED
CAPES ARE NOT IMPRESSIVE...BUT LOW LEVEL LAPSE RATES ARE
INCREASING. MODELS DO SHOW SOME LIGHT QPF DEVELOPING SO THERE MAY
BE A FEW SNOW SHOWERS DEVELOPING OVER CAPE COD AND ACK OVERNIGHT
AND WE HAVE SOME LOW CHC POPS.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
HIGHLIGHTS...

* SCT LIGHT SNOW/RAIN SHOWERS SAT INTO SUN...WITH A PERIOD OF
  DRIZZLE/FREEZING DRIZZLE POSSIBLE SAT NIGHT INTO SUN MORNING
* WEAK WAVE OF LOW PRESSURE WILL PASS WELL OFFSHORE TUE BUT COULD
  STILL SEE LIGHT PRECIP
* ANOMALOUSLY STRONG STORM SYSTEM WILL BRING HEAVY RAIN...GUSTY
  WINDS AND COASTAL CONCERNS AROUND CHRISTMAS EVE

OVERVIEW AND MODEL PREFERENCES...
MEDIUM RANGE MODELS CONTINUE IN PRETTY GOOD AGREEMENT ON LARGE
SCALE AND UPPER LEVEL FEATURES THROUGH MOST OF THE FORECAST
PERIOD.

MODELS AND ENSEMBLES CONTINUE TO SIGNAL WEAK SHORT WAVES THAT
TRANSLATE ACROSS THE REGION EARLY IN THIS PERIOD...WITH A RATHER
POTENT BUT FAST MOVING ONE FOR SAT NIGHT/SUN TIMEFRAME WHICH IS
AIDED WITH LOW LEVEL ONSHORE MOISTURE...WITH A SECOND WEAK LOW FOR
LATE MON INTO TUE BRINGING ANOTHER PERIOD OF LIGHT PRECIP.

STILL QUITE A FEW PLACEMENT AND TIMING ISSUES WITH THE EVOLUTION
OF AN ANOMALOUSLY DEEP H5 CUTOFF LOW DEVELOPING ACROSS THE WESTERN
GREAT LAKES AROUND THE MON-TUE TIMEFRAME...THEN ROTATES NE
SOMEWHERE ACROSS S CENTRAL CANADA ON CHRISTMAS DAY. BIG
IMPLICATIONS WITH THE ASSOCIATED LONG WAVE TROUGH. GUIDANCE
CONTINUES TO INDICATE THE TROUGH BECOMING NEGATIVELY TILTED ACROSS
THE MID ATLC OR SE U.S. LATE IN THIS PERIOD. SECONDARY/ TRIPLE
POINT LOW FORMS ON SURFACE FRONT OVER THE EASTERN GULF AROUND
TUESDAY...THEN WORKS UP ACROSS EASTERN PORTIONS OF THE SE AND MID
ATLC STATES. QUESTION IS IF THIS LOW APPROACHES WESTERN PORTIONS
OF NEW ENGLAND WED NIGHT.

STILL SEE THE SIGNALS FOR A FAST MOVING STORM WITH MULTIPLE
IMPACTS POSSIBLE...INCLUDING PERIOD OF HEAVY RAINFALL AND STRONG
WIND GUSTS...FIRST FROM THE SOUTH THEN SHIFTING TO THE WEST. COULD
EVEN SEE SOME COASTAL IMPACTS DURING THE HIGH TIDE CYCLE DURING
WED. TIMING REMAINS AN ISSUE...AS ONE WOULD EXPECT THIS FAR OUT.
MODEL GUIDANCE STILL DOING A RATHER GOOD JOB HANDLING GENERAL
FEATURES OF THIS SYSTEM AT THIS POINT.

USED A BLEND OF THE AVAILABLE GUIDANCE ALONG WITH WPC GUIDANCE.

DETAILS...

SATURDAY INTO SUNDAY...HIGH CONFIDENCE.
HIGH PRES AT THE SURFACE AND ALOFT MOVES ACROSS QUEBEC INTO THE
MARITIMES DURING THIS WEEKEND...THEN TENDS TO SLOW ITS EASTWARD
PROGRESS WITH BLOCKING OVER THE WESTERN ATLC. RATHER POTENT SHORT
WAVE UNDERNEATH THE UPPER SYSTEM MOVES ACROSS THE REGION...AIDED
BY A LOW LEVEL E-NE WIND IN PLACE. A LOT OF LOW LEVEL MOISTURE IN
PLACE AS SEEN ON BUFKIT MODEL SOUNDINGS...SO WILL SEE SOME LIGHT
RAIN/SNOW SHOWERS DEVELOP FROM E-W DURING SATURDAY. EXPECTING
LITTLE IF ANY SNOW ACCUMULATIONS DURING SAT.

HOWEVER...AS TEMPS FALL BACK SAT NIGHT...ALONG WITH THE DEEP LOW
LEVEL MOISTURE FEED...WILL ALSO SEE AREAS OF DRIZZLE DEVELOP. BIG
PROBLEM WILL BE JUST AWAY FROM THE COAST WHERE TEMPS FALL BELOW
FREEZING WHICH MAY MEAN FREEZING DRIZZLE. DOES NOT TAKE MUCH TO
GET GLAZING ESPECIALLY ON UNTREATED SURFACES. WILL NEED TO MONITOR
THIS CLOSELY FOR POSSIBLE WINTER WEATHER HEADLINES ACROSS INTERIOR
E MA INTO RI...POSSIBLY EVEN FURTHER W. WITH THE LIGHT
SNOW...MIGHT SEE UP TO 1/2 INCH ACCUMULATIONS SAT NIGHT INTO SUN
MORNING.

ON SUNDAY...DRIZZLE WILL TAPER OFF DURING THE MORNING...THOUGH
LEFTOVER RAIN/SNOW SHOWERS WILL LINGER THOUGH TEND TO TAPER OFF
DURING THE AFTERNOON.

MONDAY INTO TUESDAY...MODERATE CONFIDENCE.
ANOTHER COASTAL LOW LOOKS TO DEVELOP OFF THE SE U.S. COAST
AND...AS UPPER LEVEL TROUGH BEGINS TO DIG ACROSS THE CENTRAL
U.S...WILL SHIFT TO THE E-NE UNDERNEATH THE UPPER RIDGE. THE
MARITIMES SURFACE HIGH REMAINS PRETTY MUCH IN PLACE...WHICH WILL
HELP SHIFT THE MAIN EFFECTS OF THIS LOW WELL OFFSHORE /SE OF THE
40N/70W BENCHMARK/. HOWEVER...MODELS CONTINUE TO SIGNAL LIGHT
PRECIP REACHING THE COAST MAINLY MON NIGHT INTO TUE. EXPECT MAINLY
MIXED RAIN/SNOW SHOWERS WITH SPOTTY BRIEF PERIODS OF FREEZING
PRECIP AROUND DAYBREAK TUE ACROSS N CT/N RI INTO S CENTRAL MA.
EXPECT HIGH TEMPS ON TUE TO RUN ABOUT 5 DEGS ABOVE SEASONAL NORMS
AS WINDS BEGIN TO SHIFT MORE S- SE...THOUGH SOME TIMING ISSUES IN
PLACE FOR WIND SHIFT AMONGST OP MODELS.

ONCE THE LOW EXITS LATE TUE...WILL ALREADY START TO SEE MOISTURE
FEED UP THE COAST FROM THE DEVELOPING GULF LOW...SO NOT MUCH OF A
BREAK IN THE PRECIP BETWEEN SYSTEMS.

TUESDAY/S LATE MORNING HIGH TIDE WILL RUN UP TO 11.6 FT IN BOSTON
AND...WITH ANY EASTERLY WIND FLOW...THIS MAY CAUSE MINOR COASTAL
FLOODING. WILL MONITOR THIS ASPECT.

WEDNESDAY AND CHRISTMAS DAY...HIGH CONFIDENCE IN SYSTEM...LOW
CONFIDENCE ON DETAILS.

SECONDARY LOW FROM THE PARENT OVER THE NORTHERN GREAT LAKES
DEEPENS AS IT SHIFTS N. MODELS TRY TO PUSH THIS SYSTEM CLOSE TO OR
JUST INTO WESTERN NEW ENGLAND LATE WED/WED NIGHT...THOUGH STILL
TIMING ISSUES IN PLACE. AT THIS POINT...WILL SEE HEAVIEST SLUG OF
PRECIP MOVING ACROSS LATE WED INTO WED EVENING. GOOD TROPICAL
CONNECTION CONTINUES WITH PWATS FROM 1.25 TO 1.4 INCHES...RUNNING
ABOUT +2SD TO +3SD ABOVE NORMAL FOR LATE DECEMBER. GOOD SHOT OF
MILD AIR WORKS IN ON SE-S WINDS. MODELS CONTINUE TO SIGNAL H925
AND H85 FROM 50-65 KT...AND AT LEAST SOME WILL MIX DOWN ESPECIALLY
IF THE LOW PRES PASSES CLOSER /WITH RAPIDLY FALLING PRESSURE/.
HAVE HIGHS ON WED UP TO THE LOWER 50S ACROSS EASTERN AND SOUTHERN
AREAS...BUT COULD BE EVEN HIGHER WITH STRONG ONSHORE WINDS.

CURRENT TIMING SUGGESTS THE DRY SLOT SHOULD WORK INTO THE REGION
LATE WED NIGHT INTO CHRISTMAS MORNING...SO PRECIP SHOULD END. WILL
STILL SEE GUSTY WINDS...THOUGH QUICKLY SHIFTING TO W-SW AND
GUSTING UP TO 25-30 KT...HIGHEST ALONG THE S COAST.

MAY NEED HEADLINES WITH THIS SYSTEM...WITH POSSIBLE URBAN/POOR
DRAINAGE FLOODING IN HEAVY RAINFALL WED/WED NIGHT...STRONG WINDS
BOTH WED AND THU...AND MAYBE EVEN FOR COASTAL CONCERNS. NOTING
ASTRO HIGH TIDES CONTINUE /11.7 AND 11.5 FT AT BOSTON
RESPECTIVELY/... THOUGH TIMING OF WIND SHIFT MAY COME INTO PLAY
FOR CHRISTMAS EVE INTO CHRISTMAS MORNING.

FRIDAY...LOW CONFIDENCE MAINLY FOR TIMING.
ONCE UPPER LOW MOVES INTO SOUTHERN CANADA...EXPECT A RATHER FAST
UPPER W FLOW IN PLACE. MAY SEE LEFTOVER SNOW SHOWERS ACROSS THE E
SLOPES OF THE BERKSHIRES INTO THE MONADNOCKS. TEMPS WILL FALL BACK
CLOSE TO SEASONAL NORMS. ANOTHER LOW MIGHT MOVE INTO W NY STATE
FRI NIGHT.

&&

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

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

SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...

925 PM UPDATE...

OVERNIGHT...MODERATE CONFIDENCE.  A BROKEN DECK OF CLOUDS BETWEEN 2
AND 4 THOUSAND FEET ACROSS MOST OF THE REGION WILL PERSIST.
THEREFORE...EXPECT CONDITIONS TO VARY BETWEEN LOW END VFR AND MVFR.
THE LOWER CIGS WILL TEND TO BE FOUND ACROSS THE INTERIOR.

FRIDAY...LOW CONFIDENCE DUE TO UNCERTAINTY WITH EXTENT OF ANY MVFR
CIGS. WE HAVE MAINLY VFR IN THE TAFS WITH POCKETS OF MVFR...BUT
IT IS POSSIBLE MVFR CIGS COULD BE MORE EXPANSIVE IF LOW LEVEL
MOISTURE BECOMES TRAPPED BELOW THE INVERSION. LATER FORECASTS
WILL NEED TO REEVALUATE THIS.

FRIDAY NIGHT...MODERATE CONFIDENCE. MAINLY VFR...BUT MVFR CIGS
FROM THE OCEAN EXPANDING WEST ACROSS E MA. LOW PROB FOR SOME OCEAN
EFFECT SNOW SHOWERS OVER CAPE COD AND ACK AFTER MIDNIGHT.

KBOS TERMINAL...MODERATE CONFIDENCE. BROKEN DECK OF CLOUDS BETWEEN
2500 AND 4000 FEET INTO EARLY FRI MORNING.

KBDL TERMINAL...MODERATE CONFIDENCE. BROKEN DECK OF CLOUDS BETWEEN
2500 AND 4000 FEET INTO EARLY FRI MORNING

OUTLOOK...SATURDAY THROUGH TUESDAY...

SATURDAY INTO SUNDAY...HIGH CONFIDENCE. MAINLY VFR ACROSS CENTRAL
AND WESTERN AREAS. E MA INTO RI...AREAS MVFR CIGS/VSBYS IN ANY
RAIN/SNOW SHOWERS...AREAS OF DRIZZLE SAT NIGHT INTO SUN MORNING.

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 FRIDAY NIGHT/...HIGH CONFIDENCE.

925 PM UPDATE...

OVERNIGHT...W/NW GUSTS AROUND 25 KNOTS WILL CONTINUE TO GRADUALLY
DIMINISH OVERNIGHT. SCA HEADLINES WILL EXPIRE FOR THE NEAR SHORE
OPEN WATERS TOWARD DAYBREAK...BUT REMAIN ACROSS THE OUTER-WATERS
INTO FRIDAY MORNING FOR LEFT OVER SEAS.

FRIDAY...NW WINDS WILL BE BELOW SCA THRESHOLDS...BUT HAZARDOUS
SEAS WILL CONTINUE THROUGH THE MORNING OVER THE OUTER EASTERN
WATERS...BEFORE SUBSIDING BELOW SCA. WILL LIKELY NEED TO EXTEND
THE SCA FOR SEAS INTO FRI MORNING.

FRIDAY NIGHT...N/NW WINDS AND SEAS BELOW SCA.

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.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 AM EST FRIDAY FOR ANZ231-232-235-
     237-251.
     SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ250-254>256.

&&

$$
SYNOPSIS...KJC/EVT
NEAR TERM...FRANK
SHORT TERM...KJC
LONG TERM...EVT
AVIATION...FRANK/KJC/EVT
MARINE...FRANK/KJC/EVT



000
FXUS61 KBOX 190225
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
914 PM EST THU DEC 18 2014

.SYNOPSIS...
DRY AND SEASONABLE CONDITIONS WILL PREVAIL FRIDAY. AN UPPER LEVEL
DISTURBANCE AND MOIST NORTHEAST FLOW WILL BRING SOME LIGHT
PRECIPITATION SATURDAY INTO SUNDAY. LOW PRESSURE WILL LIKELY PASS
WELL SOUTH OF THE REGION TUESDAY...BUT STILL COULD BRING A PERIOD
OF LIGHT PRECIPITATION. A MUCH STRONGER STORM IS LIKELY TO BRING
HEAVY RAIN AND WIND TO SOUTHERN NEW ENGLAND WEDNESDAY INTO
WEDNESDAY EVENING. DRY BUT VERY WINDY CONDITIONS FOLLOW FOR
CHRISTMAS DAY.

&&

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

925 PM UPDATE...

CYCLONIC FLOW AROUND LOW PRESSURE ACROSS THE CANADIAN MARITIMES
WILL RESULT IN AN ABUNDANCE OF LOW CLOUDS ACROSS SOUTHERN NEW
ENGLAND OVERNIGHT.  WHILE THERE WILL BE BREAKS IN THE OVERCAST AT
TIMES...EXPECT CLOUDS TO DOMINATE.  PRESSURE GRADIENT WILL CONTINUE
TO GRADUALLY WEAKEN AS LOW LIFTS FURTHER NORTHEAST...BUT NOT ENOUGH
FOR WINDS TO DECOUPLE.  THEREFORE...AGREE WITH PREVIOUS FORECAST
THAT LOW TEMPS WILL BE ABOVE GUIDANCE NUMBERS.  BY DAYBREAK
FRI...LOW TEMPS SHOULD BOTTOM OUT IN THE 20S TO THE LOWER 30S.


&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
FRIDAY...
HIGH PRES BUILDS ACROSS THE GRT LAKES WITH NW FLOW ACROSS NEW
ENG. TRICKY CLOUD FORECAST AS NAM INDICATING LOW LEVEL MOISTURE
TRAPPED BELOW INVERSION WITH WIDESPREAD LOW CLOUDS...WHILE GFS AND
ECMWF ARE DRIER IN THE LOW LEVELS. GIVEN LOW LEVEL FLOW IS STILL
NW...WE WILL LEAN MORE OPTIMISTIC THAN NAM WITH A MIX OF CLOUDS
AND SUN EXPECTED. TEMPS WILL LIKELY BE 3-5 DEGREES COLDER THAN
TODAY GIVEN COOLING AT 925 MB...WITH MAX TEMPS RANGING FROM NEAR
30 HIGHER TERRAIN IN NORTHERN AND WESTERN MA TO UPPER 30S IN THE
COASTAL PLAIN.

FRIDAY NIGHT...
MID LEVEL SHORTWAVE MOVES INTO W NEW ENG TOWARD DAYBREAK...BUT
FORCING IS WEAK THROUGH MOST OF THE NIGHT AND MOISTURE IS LIMITED
SO EXPECTING A MAINLY DRY NIGHT. HOWEVER...AS HIGH PRES BUILDS
EASTWARD ACROSS QUEBEC LOW LEVEL WINDS BECOME NE AND MODELS
INDICATE INCREASING LOW MOISTURE BACKING IN ACROSS SE NEW ENG
OVERNIGHT. DELTA T FROM SST TO THE TOP OF THE MIXED LAYER IS
AROUND 13C WHICH IS MARGINAL FOR OCEAN EFFECT AND OCEAN INDUCED
CAPES ARE NOT IMPRESSIVE...BUT LOW LEVEL LAPSE RATES ARE
INCREASING. MODELS DO SHOW SOME LIGHT QPF DEVELOPING SO THERE MAY
BE A FEW SNOW SHOWERS DEVELOPING OVER CAPE COD AND ACK OVERNIGHT
AND WE HAVE SOME LOW CHC POPS.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
HIGHLIGHTS...

* SCT LIGHT SNOW/RAIN SHOWERS SAT INTO SUN...WITH A PERIOD OF
  DRIZZLE/FREEZING DRIZZLE POSSIBLE SAT NIGHT INTO SUN MORNING
* WEAK WAVE OF LOW PRESSURE WILL PASS WELL OFFSHORE TUE BUT COULD
  STILL SEE LIGHT PRECIP
* ANOMALOUSLY STRONG STORM SYSTEM WILL BRING HEAVY RAIN...GUSTY
  WINDS AND COASTAL CONCERNS AROUND CHRISTMAS EVE

OVERVIEW AND MODEL PREFERENCES...
MEDIUM RANGE MODELS CONTINUE IN PRETTY GOOD AGREEMENT ON LARGE
SCALE AND UPPER LEVEL FEATURES THROUGH MOST OF THE FORECAST
PERIOD.

MODELS AND ENSEMBLES CONTINUE TO SIGNAL WEAK SHORT WAVES THAT
TRANSLATE ACROSS THE REGION EARLY IN THIS PERIOD...WITH A RATHER
POTENT BUT FAST MOVING ONE FOR SAT NIGHT/SUN TIMEFRAME WHICH IS
AIDED WITH LOW LEVEL ONSHORE MOISTURE...WITH A SECOND WEAK LOW FOR
LATE MON INTO TUE BRINGING ANOTHER PERIOD OF LIGHT PRECIP.

STILL QUITE A FEW PLACEMENT AND TIMING ISSUES WITH THE EVOLUTION
OF AN ANOMALOUSLY DEEP H5 CUTOFF LOW DEVELOPING ACROSS THE WESTERN
GREAT LAKES AROUND THE MON-TUE TIMEFRAME...THEN ROTATES NE
SOMEWHERE ACROSS S CENTRAL CANADA ON CHRISTMAS DAY. BIG
IMPLICATIONS WITH THE ASSOCIATED LONG WAVE TROUGH. GUIDANCE
CONTINUES TO INDICATE THE TROUGH BECOMING NEGATIVELY TILTED ACROSS
THE MID ATLC OR SE U.S. LATE IN THIS PERIOD. SECONDARY/ TRIPLE
POINT LOW FORMS ON SURFACE FRONT OVER THE EASTERN GULF AROUND
TUESDAY...THEN WORKS UP ACROSS EASTERN PORTIONS OF THE SE AND MID
ATLC STATES. QUESTION IS IF THIS LOW APPROACHES WESTERN PORTIONS
OF NEW ENGLAND WED NIGHT.

STILL SEE THE SIGNALS FOR A FAST MOVING STORM WITH MULTIPLE
IMPACTS POSSIBLE...INCLUDING PERIOD OF HEAVY RAINFALL AND STRONG
WIND GUSTS...FIRST FROM THE SOUTH THEN SHIFTING TO THE WEST. COULD
EVEN SEE SOME COASTAL IMPACTS DURING THE HIGH TIDE CYCLE DURING
WED. TIMING REMAINS AN ISSUE...AS ONE WOULD EXPECT THIS FAR OUT.
MODEL GUIDANCE STILL DOING A RATHER GOOD JOB HANDLING GENERAL
FEATURES OF THIS SYSTEM AT THIS POINT.

USED A BLEND OF THE AVAILABLE GUIDANCE ALONG WITH WPC GUIDANCE.

DETAILS...

SATURDAY INTO SUNDAY...HIGH CONFIDENCE.
HIGH PRES AT THE SURFACE AND ALOFT MOVES ACROSS QUEBEC INTO THE
MARITIMES DURING THIS WEEKEND...THEN TENDS TO SLOW ITS EASTWARD
PROGRESS WITH BLOCKING OVER THE WESTERN ATLC. RATHER POTENT SHORT
WAVE UNDERNEATH THE UPPER SYSTEM MOVES ACROSS THE REGION...AIDED
BY A LOW LEVEL E-NE WIND IN PLACE. A LOT OF LOW LEVEL MOISTURE IN
PLACE AS SEEN ON BUFKIT MODEL SOUNDINGS...SO WILL SEE SOME LIGHT
RAIN/SNOW SHOWERS DEVELOP FROM E-W DURING SATURDAY. EXPECTING
LITTLE IF ANY SNOW ACCUMULATIONS DURING SAT.

HOWEVER...AS TEMPS FALL BACK SAT NIGHT...ALONG WITH THE DEEP LOW
LEVEL MOISTURE FEED...WILL ALSO SEE AREAS OF DRIZZLE DEVELOP. BIG
PROBLEM WILL BE JUST AWAY FROM THE COAST WHERE TEMPS FALL BELOW
FREEZING WHICH MAY MEAN FREEZING DRIZZLE. DOES NOT TAKE MUCH TO
GET GLAZING ESPECIALLY ON UNTREATED SURFACES. WILL NEED TO MONITOR
THIS CLOSELY FOR POSSIBLE WINTER WEATHER HEADLINES ACROSS INTERIOR
E MA INTO RI...POSSIBLY EVEN FURTHER W. WITH THE LIGHT
SNOW...MIGHT SEE UP TO 1/2 INCH ACCUMULATIONS SAT NIGHT INTO SUN
MORNING.

ON SUNDAY...DRIZZLE WILL TAPER OFF DURING THE MORNING...THOUGH
LEFTOVER RAIN/SNOW SHOWERS WILL LINGER THOUGH TEND TO TAPER OFF
DURING THE AFTERNOON.

MONDAY INTO TUESDAY...MODERATE CONFIDENCE.
ANOTHER COASTAL LOW LOOKS TO DEVELOP OFF THE SE U.S. COAST
AND...AS UPPER LEVEL TROUGH BEGINS TO DIG ACROSS THE CENTRAL
U.S...WILL SHIFT TO THE E-NE UNDERNEATH THE UPPER RIDGE. THE
MARITIMES SURFACE HIGH REMAINS PRETTY MUCH IN PLACE...WHICH WILL
HELP SHIFT THE MAIN EFFECTS OF THIS LOW WELL OFFSHORE /SE OF THE
40N/70W BENCHMARK/. HOWEVER...MODELS CONTINUE TO SIGNAL LIGHT
PRECIP REACHING THE COAST MAINLY MON NIGHT INTO TUE. EXPECT MAINLY
MIXED RAIN/SNOW SHOWERS WITH SPOTTY BRIEF PERIODS OF FREEZING
PRECIP AROUND DAYBREAK TUE ACROSS N CT/N RI INTO S CENTRAL MA.
EXPECT HIGH TEMPS ON TUE TO RUN ABOUT 5 DEGS ABOVE SEASONAL NORMS
AS WINDS BEGIN TO SHIFT MORE S- SE...THOUGH SOME TIMING ISSUES IN
PLACE FOR WIND SHIFT AMONGST OP MODELS.

ONCE THE LOW EXITS LATE TUE...WILL ALREADY START TO SEE MOISTURE
FEED UP THE COAST FROM THE DEVELOPING GULF LOW...SO NOT MUCH OF A
BREAK IN THE PRECIP BETWEEN SYSTEMS.

TUESDAY/S LATE MORNING HIGH TIDE WILL RUN UP TO 11.6 FT IN BOSTON
AND...WITH ANY EASTERLY WIND FLOW...THIS MAY CAUSE MINOR COASTAL
FLOODING. WILL MONITOR THIS ASPECT.

WEDNESDAY AND CHRISTMAS DAY...HIGH CONFIDENCE IN SYSTEM...LOW
CONFIDENCE ON DETAILS.

SECONDARY LOW FROM THE PARENT OVER THE NORTHERN GREAT LAKES
DEEPENS AS IT SHIFTS N. MODELS TRY TO PUSH THIS SYSTEM CLOSE TO OR
JUST INTO WESTERN NEW ENGLAND LATE WED/WED NIGHT...THOUGH STILL
TIMING ISSUES IN PLACE. AT THIS POINT...WILL SEE HEAVIEST SLUG OF
PRECIP MOVING ACROSS LATE WED INTO WED EVENING. GOOD TROPICAL
CONNECTION CONTINUES WITH PWATS FROM 1.25 TO 1.4 INCHES...RUNNING
ABOUT +2SD TO +3SD ABOVE NORMAL FOR LATE DECEMBER. GOOD SHOT OF
MILD AIR WORKS IN ON SE-S WINDS. MODELS CONTINUE TO SIGNAL H925
AND H85 FROM 50-65 KT...AND AT LEAST SOME WILL MIX DOWN ESPECIALLY
IF THE LOW PRES PASSES CLOSER /WITH RAPIDLY FALLING PRESSURE/.
HAVE HIGHS ON WED UP TO THE LOWER 50S ACROSS EASTERN AND SOUTHERN
AREAS...BUT COULD BE EVEN HIGHER WITH STRONG ONSHORE WINDS.

CURRENT TIMING SUGGESTS THE DRY SLOT SHOULD WORK INTO THE REGION
LATE WED NIGHT INTO CHRISTMAS MORNING...SO PRECIP SHOULD END. WILL
STILL SEE GUSTY WINDS...THOUGH QUICKLY SHIFTING TO W-SW AND
GUSTING UP TO 25-30 KT...HIGHEST ALONG THE S COAST.

MAY NEED HEADLINES WITH THIS SYSTEM...WITH POSSIBLE URBAN/POOR
DRAINAGE FLOODING IN HEAVY RAINFALL WED/WED NIGHT...STRONG WINDS
BOTH WED AND THU...AND MAYBE EVEN FOR COASTAL CONCERNS. NOTING
ASTRO HIGH TIDES CONTINUE /11.7 AND 11.5 FT AT BOSTON
RESPECTIVELY/... THOUGH TIMING OF WIND SHIFT MAY COME INTO PLAY
FOR CHRISTMAS EVE INTO CHRISTMAS MORNING.

FRIDAY...LOW CONFIDENCE MAINLY FOR TIMING.
ONCE UPPER LOW MOVES INTO SOUTHERN CANADA...EXPECT A RATHER FAST
UPPER W FLOW IN PLACE. MAY SEE LEFTOVER SNOW SHOWERS ACROSS THE E
SLOPES OF THE BERKSHIRES INTO THE MONADNOCKS. TEMPS WILL FALL BACK
CLOSE TO SEASONAL NORMS. ANOTHER LOW MIGHT MOVE INTO W NY STATE
FRI NIGHT.

&&

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

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

SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...

925 PM UPDATE...

OVERNIGHT...MODERATE CONFIDENCE.  A BROKEN DECK OF CLOUDS BETWEEN 2
AND 4 THOUSAND FEET ACROSS MOST OF THE REGION WILL PERSIST.
THEREFORE...EXPECT CONDITIONS TO VARY BETWEEN LOW END VFR AND MVFR.
THE LOWER CIGS WILL TEND TO BE FOUND ACROSS THE INTERIOR.

FRIDAY...LOW CONFIDENCE DUE TO UNCERTAINTY WITH EXTENT OF ANY MVFR
CIGS. WE HAVE MAINLY VFR IN THE TAFS WITH POCKETS OF MVFR...BUT
IT IS POSSIBLE MVFR CIGS COULD BE MORE EXPANSIVE IF LOW LEVEL
MOISTURE BECOMES TRAPPED BELOW THE INVERSION. LATER FORECASTS
WILL NEED TO REEVALUATE THIS.

FRIDAY NIGHT...MODERATE CONFIDENCE. MAINLY VFR...BUT MVFR CIGS
FROM THE OCEAN EXPANDING WEST ACROSS E MA. LOW PROB FOR SOME OCEAN
EFFECT SNOW SHOWERS OVER CAPE COD AND ACK AFTER MIDNIGHT.

KBOS TERMINAL...MODERATE CONFIDENCE. BROKEN DECK OF CLOUDS BETWEEN
2500 AND 4000 FEET INTO EARLY FRI MORNING.

KBDL TERMINAL...MODERATE CONFIDENCE. BROKEN DECK OF CLOUDS BETWEEN
2500 AND 4000 FEET INTO EARLY FRI MORNING

OUTLOOK...SATURDAY THROUGH TUESDAY...

SATURDAY INTO SUNDAY...HIGH CONFIDENCE. MAINLY VFR ACROSS CENTRAL
AND WESTERN AREAS. E MA INTO RI...AREAS MVFR CIGS/VSBYS IN ANY
RAIN/SNOW SHOWERS...AREAS OF DRIZZLE SAT NIGHT INTO SUN MORNING.

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 FRIDAY NIGHT/...HIGH CONFIDENCE.

925 PM UPDATE...

OVERNIGHT...W/NW GUSTS AROUND 25 KNOTS WILL CONTINUE TO GRADUALLY
DIMINISH OVERNIGHT. SCA HEADLINES WILL EXPIRE FOR THE NEAR SHORE
OPEN WATERS TOWARD DAYBREAK...BUT REMAIN ACROSS THE OUTER-WATERS
INTO FRIDAY MORNING FOR LEFT OVER SEAS.

FRIDAY...NW WINDS WILL BE BELOW SCA THRESHOLDS...BUT HAZARDOUS
SEAS WILL CONTINUE THROUGH THE MORNING OVER THE OUTER EASTERN
WATERS...BEFORE SUBSIDING BELOW SCA. WILL LIKELY NEED TO EXTEND
THE SCA FOR SEAS INTO FRI MORNING.

FRIDAY NIGHT...N/NW WINDS AND SEAS BELOW SCA.

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.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 AM EST FRIDAY FOR ANZ231-232-235-
     237-251.
     SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ250-254>256.

&&

$$
SYNOPSIS...KJC/EVT
NEAR TERM...FRANK
SHORT TERM...KJC
LONG TERM...EVT
AVIATION...FRANK/KJC/EVT
MARINE...FRANK/KJC/EVT



000
FXUS61 KBOX 190006
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
706 PM EST THU DEC 18 2014

.SYNOPSIS...
DRY AND SEASONABLE CONDITIONS WILL PREVAIL FRIDAY. AN UPPER LEVEL
DISTURBANCE AND MOIST NORTHEAST FLOW WILL BRING SOME LIGHT
PRECIPITATION SATURDAY INTO SUNDAY. LOW PRESSURE WILL LIKELY PASS
WELL SOUTH OF THE REGION TUESDAY...BUT STILL COULD BRING A PERIOD
OF LIGHT PRECIPITATION. A MUCH STRONGER STORM IS LIKELY TO BRING
HEAVY RAIN AND WIND TO SOUTHERN NEW ENGLAND WEDNESDAY INTO
WEDNESDAY EVENING. DRY BUT VERY WINDY CONDITIONS FOLLOW FOR
CHRISTMAS DAY.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
650 PM UPDATE...
NOTING SOME BREAKS IN THE CLOUDS ON LATEST IR SATELLITE IMAGERY
BUT SURFACE OBS SHOWING LOW BKN-OVC WHICH ARE TOUGH TO PICK UP ON
THE IR. TEMPS REMAIN IN THE MID 30S TO LOWER 40S AT 23Z AND 00Z
WITH STEADY W-NW WINDS.

FORECAST IN PRETTY GOOD SHAPE...THOUGH DID UPDATE THE NEAR TERM TO
BRING CURRENT.

PREVIOUS DISCUSSION...
LOW PRES MOVES NE FROM THE MARITIMES BUT CYCLONIC FLOW WILL
PERSIST ALONG WITH SOME MOISTURE IN THE COLUMN WHICH WILL KEEP A
FEW CLOUDS ACROSS THE REGION ALTHOUGH DRY WEATHER EXPECTED. WHILE
GUSTY WINDS WILL DIMINISH TONIGHT...THERE IS ENOUGH PRESSURE
GRADIENT TO KEEP THE WINDS UP SO TEMPS WILL NOT DROP OFF THAT
QUICKLY. USED A BLEND OF AVAILABLE GUIDANCE WHICH SUGGESTS MIN
TEMPS MOSTLY IN THE 20S...WITH LOWER 30S OVER THE OUTER
CAPE/ISLANDS.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
FRIDAY...
HIGH PRES BUILDS ACROSS THE GRT LAKES WITH NW FLOW ACROSS NEW
ENG. TRICKY CLOUD FORECAST AS NAM INDICATING LOW LEVEL MOISTURE
TRAPPED BELOW INVERSION WITH WIDESPREAD LOW CLOUDS...WHILE GFS AND
ECMWF ARE DRIER IN THE LOW LEVELS. GIVEN LOW LEVEL FLOW IS STILL
NW...WE WILL LEAN MORE OPTIMISTIC THAN NAM WITH A MIX OF CLOUDS
AND SUN EXPECTED. TEMPS WILL LIKELY BE 3-5 DEGREES COLDER THAN
TODAY GIVEN COOLING AT 925 MB...WITH MAX TEMPS RANGING FROM NEAR
30 HIGHER TERRAIN IN NORTHERN AND WESTERN MA TO UPPER 30S IN THE
COASTAL PLAIN.

FRIDAY NIGHT...
MID LEVEL SHORTWAVE MOVES INTO W NEW ENG TOWARD DAYBREAK...BUT
FORCING IS WEAK THROUGH MOST OF THE NIGHT AND MOISTURE IS LIMITED
SO EXPECTING A MAINLY DRY NIGHT. HOWEVER...AS HIGH PRES BUILDS
EASTWARD ACROSS QUEBEC LOW LEVEL WINDS BECOME NE AND MODELS
INDICATE INCREASING LOW MOISTURE BACKING IN ACROSS SE NEW ENG
OVERNIGHT. DELTA T FROM SST TO THE TOP OF THE MIXED LAYER IS
AROUND 13C WHICH IS MARGINAL FOR OCEAN EFFECT AND OCEAN INDUCED
CAPES ARE NOT IMPRESSIVE...BUT LOW LEVEL LAPSE RATES ARE
INCREASING. MODELS DO SHOW SOME LIGHT QPF DEVELOPING SO THERE MAY
BE A FEW SNOW SHOWERS DEVELOPING OVER CAPE COD AND ACK OVERNIGHT
AND WE HAVE SOME LOW CHC POPS.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
HIGHLIGHTS...

* SCT LIGHT SNOW/RAIN SHOWERS SAT INTO SUN...WITH A PERIOD OF
  DRIZZLE/FREEZING DRIZZLE POSSIBLE SAT NIGHT INTO SUN MORNING
* WEAK WAVE OF LOW PRESSURE WILL PASS WELL OFFSHORE TUE BUT COULD
  STILL SEE LIGHT PRECIP
* ANOMALOUSLY STRONG STORM SYSTEM WILL BRING HEAVY RAIN...GUSTY
  WINDS AND COASTAL CONCERNS AROUND CHRISTMAS EVE

OVERVIEW AND MODEL PREFERENCES...
MEDIUM RANGE MODELS CONTINUE IN PRETTY GOOD AGREEMENT ON LARGE
SCALE AND UPPER LEVEL FEATURES THROUGH MOST OF THE FORECAST
PERIOD.

MODELS AND ENSEMBLES CONTINUE TO SIGNAL WEAK SHORT WAVES THAT
TRANSLATE ACROSS THE REGION EARLY IN THIS PERIOD...WITH A RATHER
POTENT BUT FAST MOVING ONE FOR SAT NIGHT/SUN TIMEFRAME WHICH IS
AIDED WITH LOW LEVEL ONSHORE MOISTURE...WITH A SECOND WEAK LOW FOR
LATE MON INTO TUE BRINGING ANOTHER PERIOD OF LIGHT PRECIP.

STILL QUITE A FEW PLACEMENT AND TIMING ISSUES WITH THE EVOLUTION
OF AN ANOMALOUSLY DEEP H5 CUTOFF LOW DEVELOPING ACROSS THE WESTERN
GREAT LAKES AROUND THE MON-TUE TIMEFRAME...THEN ROTATES NE
SOMEWHERE ACROSS S CENTRAL CANADA ON CHRISTMAS DAY. BIG
IMPLICATIONS WITH THE ASSOCIATED LONG WAVE TROUGH. GUIDANCE
CONTINUES TO INDICATE THE TROUGH BECOMING NEGATIVELY TILTED ACROSS
THE MID ATLC OR SE U.S. LATE IN THIS PERIOD. SECONDARY/ TRIPLE
POINT LOW FORMS ON SURFACE FRONT OVER THE EASTERN GULF AROUND
TUESDAY...THEN WORKS UP ACROSS EASTERN PORTIONS OF THE SE AND MID
ATLC STATES. QUESTION IS IF THIS LOW APPROACHES WESTERN PORTIONS
OF NEW ENGLAND WED NIGHT.

STILL SEE THE SIGNALS FOR A FAST MOVING STORM WITH MULTIPLE
IMPACTS POSSIBLE...INCLUDING PERIOD OF HEAVY RAINFALL AND STRONG
WIND GUSTS...FIRST FROM THE SOUTH THEN SHIFTING TO THE WEST. COULD
EVEN SEE SOME COASTAL IMPACTS DURING THE HIGH TIDE CYCLE DURING
WED. TIMING REMAINS AN ISSUE...AS ONE WOULD EXPECT THIS FAR OUT.
MODEL GUIDANCE STILL DOING A RATHER GOOD JOB HANDLING GENERAL
FEATURES OF THIS SYSTEM AT THIS POINT.

USED A BLEND OF THE AVAILABLE GUIDANCE ALONG WITH WPC GUIDANCE.

DETAILS...

SATURDAY INTO SUNDAY...HIGH CONFIDENCE.
HIGH PRES AT THE SURFACE AND ALOFT MOVES ACROSS QUEBEC INTO THE
MARITIMES DURING THIS WEEKEND...THEN TENDS TO SLOW ITS EASTWARD
PROGRESS WITH BLOCKING OVER THE WESTERN ATLC. RATHER POTENT SHORT
WAVE UNDERNEATH THE UPPER SYSTEM MOVES ACROSS THE REGION...AIDED
BY A LOW LEVEL E-NE WIND IN PLACE. A LOT OF LOW LEVEL MOISTURE IN
PLACE AS SEEN ON BUFKIT MODEL SOUNDINGS...SO WILL SEE SOME LIGHT
RAIN/SNOW SHOWERS DEVELOP FROM E-W DURING SATURDAY. EXPECTING
LITTLE IF ANY SNOW ACCUMULATIONS DURING SAT.

HOWEVER...AS TEMPS FALL BACK SAT NIGHT...ALONG WITH THE DEEP LOW
LEVEL MOISTURE FEED...WILL ALSO SEE AREAS OF DRIZZLE DEVELOP. BIG
PROBLEM WILL BE JUST AWAY FROM THE COAST WHERE TEMPS FALL BELOW
FREEZING WHICH MAY MEAN FREEZING DRIZZLE. DOES NOT TAKE MUCH TO
GET GLAZING ESPECIALLY ON UNTREATED SURFACES. WILL NEED TO MONITOR
THIS CLOSELY FOR POSSIBLE WINTER WEATHER HEADLINES ACROSS INTERIOR
E MA INTO RI...POSSIBLY EVEN FURTHER W. WITH THE LIGHT
SNOW...MIGHT SEE UP TO 1/2 INCH ACCUMULATIONS SAT NIGHT INTO SUN
MORNING.

ON SUNDAY...DRIZZLE WILL TAPER OFF DURING THE MORNING...THOUGH
LEFTOVER RAIN/SNOW SHOWERS WILL LINGER THOUGH TEND TO TAPER OFF
DURING THE AFTERNOON.

MONDAY INTO TUESDAY...MODERATE CONFIDENCE.
ANOTHER COASTAL LOW LOOKS TO DEVELOP OFF THE SE U.S. COAST
AND...AS UPPER LEVEL TROUGH BEGINS TO DIG ACROSS THE CENTRAL
U.S...WILL SHIFT TO THE E-NE UNDERNEATH THE UPPER RIDGE. THE
MARITIMES SURFACE HIGH REMAINS PRETTY MUCH IN PLACE...WHICH WILL
HELP SHIFT THE MAIN EFFECTS OF THIS LOW WELL OFFSHORE /SE OF THE
40N/70W BENCHMARK/. HOWEVER...MODELS CONTINUE TO SIGNAL LIGHT
PRECIP REACHING THE COAST MAINLY MON NIGHT INTO TUE. EXPECT MAINLY
MIXED RAIN/SNOW SHOWERS WITH SPOTTY BRIEF PERIODS OF FREEZING
PRECIP AROUND DAYBREAK TUE ACROSS N CT/N RI INTO S CENTRAL MA.
EXPECT HIGH TEMPS ON TUE TO RUN ABOUT 5 DEGS ABOVE SEASONAL NORMS
AS WINDS BEGIN TO SHIFT MORE S- SE...THOUGH SOME TIMING ISSUES IN
PLACE FOR WIND SHIFT AMONGST OP MODELS.

ONCE THE LOW EXITS LATE TUE...WILL ALREADY START TO SEE MOISTURE
FEED UP THE COAST FROM THE DEVELOPING GULF LOW...SO NOT MUCH OF A
BREAK IN THE PRECIP BETWEEN SYSTEMS.

TUESDAY/S LATE MORNING HIGH TIDE WILL RUN UP TO 11.6 FT IN BOSTON
AND...WITH ANY EASTERLY WIND FLOW...THIS MAY CAUSE MINOR COASTAL
FLOODING. WILL MONITOR THIS ASPECT.

WEDNESDAY AND CHRISTMAS DAY...HIGH CONFIDENCE IN SYSTEM...LOW
CONFIDENCE ON DETAILS.

SECONDARY LOW FROM THE PARENT OVER THE NORTHERN GREAT LAKES
DEEPENS AS IT SHIFTS N. MODELS TRY TO PUSH THIS SYSTEM CLOSE TO OR
JUST INTO WESTERN NEW ENGLAND LATE WED/WED NIGHT...THOUGH STILL
TIMING ISSUES IN PLACE. AT THIS POINT...WILL SEE HEAVIEST SLUG OF
PRECIP MOVING ACROSS LATE WED INTO WED EVENING. GOOD TROPICAL
CONNECTION CONTINUES WITH PWATS FROM 1.25 TO 1.4 INCHES...RUNNING
ABOUT +2SD TO +3SD ABOVE NORMAL FOR LATE DECEMBER. GOOD SHOT OF
MILD AIR WORKS IN ON SE-S WINDS. MODELS CONTINUE TO SIGNAL H925
AND H85 FROM 50-65 KT...AND AT LEAST SOME WILL MIX DOWN ESPECIALLY
IF THE LOW PRES PASSES CLOSER /WITH RAPIDLY FALLING PRESSURE/.
HAVE HIGHS ON WED UP TO THE LOWER 50S ACROSS EASTERN AND SOUTHERN
AREAS...BUT COULD BE EVEN HIGHER WITH STRONG ONSHORE WINDS.

CURRENT TIMING SUGGESTS THE DRY SLOT SHOULD WORK INTO THE REGION
LATE WED NIGHT INTO CHRISTMAS MORNING...SO PRECIP SHOULD END. WILL
STILL SEE GUSTY WINDS...THOUGH QUICKLY SHIFTING TO W-SW AND
GUSTING UP TO 25-30 KT...HIGHEST ALONG THE S COAST.

MAY NEED HEADLINES WITH THIS SYSTEM...WITH POSSIBLE URBAN/POOR
DRAINAGE FLOODING IN HEAVY RAINFALL WED/WED NIGHT...STRONG WINDS
BOTH WED AND THU...AND MAYBE EVEN FOR COASTAL CONCERNS. NOTING
ASTRO HIGH TIDES CONTINUE /11.7 AND 11.5 FT AT BOSTON
RESPECTIVELY/... THOUGH TIMING OF WIND SHIFT MAY COME INTO PLAY
FOR CHRISTMAS EVE INTO CHRISTMAS MORNING.

FRIDAY...LOW CONFIDENCE MAINLY FOR TIMING.
ONCE UPPER LOW MOVES INTO SOUTHERN CANADA...EXPECT A RATHER FAST
UPPER W FLOW IN PLACE. MAY SEE LEFTOVER SNOW SHOWERS ACROSS THE E
SLOPES OF THE BERKSHIRES INTO THE MONADNOCKS. TEMPS WILL FALL BACK
CLOSE TO SEASONAL NORMS. ANOTHER LOW MIGHT MOVE INTO W NY STATE
FRI NIGHT.

&&

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

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

SHORT TERM /TODAY THROUGH FRIDAY NIGHT/...

THROUGH 00Z...LOW VFR/MVFR CIGS AROUND 3000-3500 FT. TREND SHOULD
BE FOR CLOUD DECK TO BECOME SCT TOWARD 00Z..ESPECIALLY NEAR THE
COAST. W/NW GUSTS TO 25-30 KT.

TONIGHT...MODERATE CONFIDENCE. MAINLY VFR...BUT LINGERING MVFR
CIGS ACROSS N CENTRAL-NW MA AND HIGHER TERRAIN THROUGH 03Z OR SO.
DIMINISHING WIND.

FRIDAY...LOW CONFIDENCE DUE TO UNCERTAINTY WITH EXTENT OF ANY MVFR
CIGS. WE HAVE MAINLY VFR IN THE TAFS WITH POCKETS OF MVFR...BUT
IT IS POSSIBLE MVFR CIGS COULD BE MORE EXPANSIVE IF LOW LEVEL
MOISTURE BECOMES TRAPPED BELOW THE INVERSION. LATER FORECASTS
WILL NEED TO REEVALUATE THIS.

FRIDAY NIGHT...MODERATE CONFIDENCE. MAINLY VFR...BUT MVFR CIGS
FROM THE OCEAN EXPANDING WEST ACROSS E MA. LOW PROB FOR SOME OCEAN
EFFECT SNOW SHOWERS OVER CAPE COD AND ACK AFTER MIDNIGHT.

KBOS TERMINAL...MODERATE CONFIDENCE. MAINLY VFR...BUT LOW PROB
FOR MVFR CIGS FRIDAY.

KBDL TERMINAL...MODERATE CONFIDENCE. SHOULD SEE MVFR CIGS SCATTER
OUT THIS EVENING. MVFR CIGS MAY RETURN FRI BUT THIS IS UNCERTAIN.

OUTLOOK...SATURDAY THROUGH TUESDAY...

SATURDAY INTO SUNDAY...HIGH CONFIDENCE. MAINLY VFR ACROSS CENTRAL
AND WESTERN AREAS. E MA INTO RI...AREAS MVFR CIGS/VSBYS IN ANY
RAIN/SNOW SHOWERS...AREAS OF DRIZZLE SAT NIGHT INTO SUN MORNING.

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 FRIDAY NIGHT/...HIGH CONFIDENCE.

TONIGHT...W/NW GUSTS 25-30 KT WILL LINGER OVER THE WATERS INTO
THIS EVENING BEFORE DIMINISHING OVERNIGHT. SCA HEADLINES WILL
CONTINUE TONIGHT.

FRIDAY...NW WINDS WILL BE BELOW SCA THRESHOLDS...BUT HAZARDOUS
SEAS WILL CONTINUE THROUGH THE MORNING OVER THE OUTER EASTERN
WATERS...BEFORE SUBSIDING BELOW SCA. WILL LIKELY NEED TO EXTEND
THE SCA FOR SEAS INTO FRI MORNING.

FRIDAY NIGHT...N/NW WINDS AND SEAS BELOW SCA.

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.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 AM EST FRIDAY FOR ANZ231-232-251.
     SMALL CRAFT ADVISORY UNTIL 11 PM EST THIS EVENING FOR
     ANZ233>235-237.
     SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR ANZ230-
     236.
     SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ250-254>256.

&&

$$
SYNOPSIS...KJC/EVT
NEAR TERM...KJC/EVT
SHORT TERM...KJC
LONG TERM...EVT
AVIATION...KJC/EVT
MARINE...KJC/EVT



000
FXUS61 KBOX 190006
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
706 PM EST THU DEC 18 2014

.SYNOPSIS...
DRY AND SEASONABLE CONDITIONS WILL PREVAIL FRIDAY. AN UPPER LEVEL
DISTURBANCE AND MOIST NORTHEAST FLOW WILL BRING SOME LIGHT
PRECIPITATION SATURDAY INTO SUNDAY. LOW PRESSURE WILL LIKELY PASS
WELL SOUTH OF THE REGION TUESDAY...BUT STILL COULD BRING A PERIOD
OF LIGHT PRECIPITATION. A MUCH STRONGER STORM IS LIKELY TO BRING
HEAVY RAIN AND WIND TO SOUTHERN NEW ENGLAND WEDNESDAY INTO
WEDNESDAY EVENING. DRY BUT VERY WINDY CONDITIONS FOLLOW FOR
CHRISTMAS DAY.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
650 PM UPDATE...
NOTING SOME BREAKS IN THE CLOUDS ON LATEST IR SATELLITE IMAGERY
BUT SURFACE OBS SHOWING LOW BKN-OVC WHICH ARE TOUGH TO PICK UP ON
THE IR. TEMPS REMAIN IN THE MID 30S TO LOWER 40S AT 23Z AND 00Z
WITH STEADY W-NW WINDS.

FORECAST IN PRETTY GOOD SHAPE...THOUGH DID UPDATE THE NEAR TERM TO
BRING CURRENT.

PREVIOUS DISCUSSION...
LOW PRES MOVES NE FROM THE MARITIMES BUT CYCLONIC FLOW WILL
PERSIST ALONG WITH SOME MOISTURE IN THE COLUMN WHICH WILL KEEP A
FEW CLOUDS ACROSS THE REGION ALTHOUGH DRY WEATHER EXPECTED. WHILE
GUSTY WINDS WILL DIMINISH TONIGHT...THERE IS ENOUGH PRESSURE
GRADIENT TO KEEP THE WINDS UP SO TEMPS WILL NOT DROP OFF THAT
QUICKLY. USED A BLEND OF AVAILABLE GUIDANCE WHICH SUGGESTS MIN
TEMPS MOSTLY IN THE 20S...WITH LOWER 30S OVER THE OUTER
CAPE/ISLANDS.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
FRIDAY...
HIGH PRES BUILDS ACROSS THE GRT LAKES WITH NW FLOW ACROSS NEW
ENG. TRICKY CLOUD FORECAST AS NAM INDICATING LOW LEVEL MOISTURE
TRAPPED BELOW INVERSION WITH WIDESPREAD LOW CLOUDS...WHILE GFS AND
ECMWF ARE DRIER IN THE LOW LEVELS. GIVEN LOW LEVEL FLOW IS STILL
NW...WE WILL LEAN MORE OPTIMISTIC THAN NAM WITH A MIX OF CLOUDS
AND SUN EXPECTED. TEMPS WILL LIKELY BE 3-5 DEGREES COLDER THAN
TODAY GIVEN COOLING AT 925 MB...WITH MAX TEMPS RANGING FROM NEAR
30 HIGHER TERRAIN IN NORTHERN AND WESTERN MA TO UPPER 30S IN THE
COASTAL PLAIN.

FRIDAY NIGHT...
MID LEVEL SHORTWAVE MOVES INTO W NEW ENG TOWARD DAYBREAK...BUT
FORCING IS WEAK THROUGH MOST OF THE NIGHT AND MOISTURE IS LIMITED
SO EXPECTING A MAINLY DRY NIGHT. HOWEVER...AS HIGH PRES BUILDS
EASTWARD ACROSS QUEBEC LOW LEVEL WINDS BECOME NE AND MODELS
INDICATE INCREASING LOW MOISTURE BACKING IN ACROSS SE NEW ENG
OVERNIGHT. DELTA T FROM SST TO THE TOP OF THE MIXED LAYER IS
AROUND 13C WHICH IS MARGINAL FOR OCEAN EFFECT AND OCEAN INDUCED
CAPES ARE NOT IMPRESSIVE...BUT LOW LEVEL LAPSE RATES ARE
INCREASING. MODELS DO SHOW SOME LIGHT QPF DEVELOPING SO THERE MAY
BE A FEW SNOW SHOWERS DEVELOPING OVER CAPE COD AND ACK OVERNIGHT
AND WE HAVE SOME LOW CHC POPS.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
HIGHLIGHTS...

* SCT LIGHT SNOW/RAIN SHOWERS SAT INTO SUN...WITH A PERIOD OF
  DRIZZLE/FREEZING DRIZZLE POSSIBLE SAT NIGHT INTO SUN MORNING
* WEAK WAVE OF LOW PRESSURE WILL PASS WELL OFFSHORE TUE BUT COULD
  STILL SEE LIGHT PRECIP
* ANOMALOUSLY STRONG STORM SYSTEM WILL BRING HEAVY RAIN...GUSTY
  WINDS AND COASTAL CONCERNS AROUND CHRISTMAS EVE

OVERVIEW AND MODEL PREFERENCES...
MEDIUM RANGE MODELS CONTINUE IN PRETTY GOOD AGREEMENT ON LARGE
SCALE AND UPPER LEVEL FEATURES THROUGH MOST OF THE FORECAST
PERIOD.

MODELS AND ENSEMBLES CONTINUE TO SIGNAL WEAK SHORT WAVES THAT
TRANSLATE ACROSS THE REGION EARLY IN THIS PERIOD...WITH A RATHER
POTENT BUT FAST MOVING ONE FOR SAT NIGHT/SUN TIMEFRAME WHICH IS
AIDED WITH LOW LEVEL ONSHORE MOISTURE...WITH A SECOND WEAK LOW FOR
LATE MON INTO TUE BRINGING ANOTHER PERIOD OF LIGHT PRECIP.

STILL QUITE A FEW PLACEMENT AND TIMING ISSUES WITH THE EVOLUTION
OF AN ANOMALOUSLY DEEP H5 CUTOFF LOW DEVELOPING ACROSS THE WESTERN
GREAT LAKES AROUND THE MON-TUE TIMEFRAME...THEN ROTATES NE
SOMEWHERE ACROSS S CENTRAL CANADA ON CHRISTMAS DAY. BIG
IMPLICATIONS WITH THE ASSOCIATED LONG WAVE TROUGH. GUIDANCE
CONTINUES TO INDICATE THE TROUGH BECOMING NEGATIVELY TILTED ACROSS
THE MID ATLC OR SE U.S. LATE IN THIS PERIOD. SECONDARY/ TRIPLE
POINT LOW FORMS ON SURFACE FRONT OVER THE EASTERN GULF AROUND
TUESDAY...THEN WORKS UP ACROSS EASTERN PORTIONS OF THE SE AND MID
ATLC STATES. QUESTION IS IF THIS LOW APPROACHES WESTERN PORTIONS
OF NEW ENGLAND WED NIGHT.

STILL SEE THE SIGNALS FOR A FAST MOVING STORM WITH MULTIPLE
IMPACTS POSSIBLE...INCLUDING PERIOD OF HEAVY RAINFALL AND STRONG
WIND GUSTS...FIRST FROM THE SOUTH THEN SHIFTING TO THE WEST. COULD
EVEN SEE SOME COASTAL IMPACTS DURING THE HIGH TIDE CYCLE DURING
WED. TIMING REMAINS AN ISSUE...AS ONE WOULD EXPECT THIS FAR OUT.
MODEL GUIDANCE STILL DOING A RATHER GOOD JOB HANDLING GENERAL
FEATURES OF THIS SYSTEM AT THIS POINT.

USED A BLEND OF THE AVAILABLE GUIDANCE ALONG WITH WPC GUIDANCE.

DETAILS...

SATURDAY INTO SUNDAY...HIGH CONFIDENCE.
HIGH PRES AT THE SURFACE AND ALOFT MOVES ACROSS QUEBEC INTO THE
MARITIMES DURING THIS WEEKEND...THEN TENDS TO SLOW ITS EASTWARD
PROGRESS WITH BLOCKING OVER THE WESTERN ATLC. RATHER POTENT SHORT
WAVE UNDERNEATH THE UPPER SYSTEM MOVES ACROSS THE REGION...AIDED
BY A LOW LEVEL E-NE WIND IN PLACE. A LOT OF LOW LEVEL MOISTURE IN
PLACE AS SEEN ON BUFKIT MODEL SOUNDINGS...SO WILL SEE SOME LIGHT
RAIN/SNOW SHOWERS DEVELOP FROM E-W DURING SATURDAY. EXPECTING
LITTLE IF ANY SNOW ACCUMULATIONS DURING SAT.

HOWEVER...AS TEMPS FALL BACK SAT NIGHT...ALONG WITH THE DEEP LOW
LEVEL MOISTURE FEED...WILL ALSO SEE AREAS OF DRIZZLE DEVELOP. BIG
PROBLEM WILL BE JUST AWAY FROM THE COAST WHERE TEMPS FALL BELOW
FREEZING WHICH MAY MEAN FREEZING DRIZZLE. DOES NOT TAKE MUCH TO
GET GLAZING ESPECIALLY ON UNTREATED SURFACES. WILL NEED TO MONITOR
THIS CLOSELY FOR POSSIBLE WINTER WEATHER HEADLINES ACROSS INTERIOR
E MA INTO RI...POSSIBLY EVEN FURTHER W. WITH THE LIGHT
SNOW...MIGHT SEE UP TO 1/2 INCH ACCUMULATIONS SAT NIGHT INTO SUN
MORNING.

ON SUNDAY...DRIZZLE WILL TAPER OFF DURING THE MORNING...THOUGH
LEFTOVER RAIN/SNOW SHOWERS WILL LINGER THOUGH TEND TO TAPER OFF
DURING THE AFTERNOON.

MONDAY INTO TUESDAY...MODERATE CONFIDENCE.
ANOTHER COASTAL LOW LOOKS TO DEVELOP OFF THE SE U.S. COAST
AND...AS UPPER LEVEL TROUGH BEGINS TO DIG ACROSS THE CENTRAL
U.S...WILL SHIFT TO THE E-NE UNDERNEATH THE UPPER RIDGE. THE
MARITIMES SURFACE HIGH REMAINS PRETTY MUCH IN PLACE...WHICH WILL
HELP SHIFT THE MAIN EFFECTS OF THIS LOW WELL OFFSHORE /SE OF THE
40N/70W BENCHMARK/. HOWEVER...MODELS CONTINUE TO SIGNAL LIGHT
PRECIP REACHING THE COAST MAINLY MON NIGHT INTO TUE. EXPECT MAINLY
MIXED RAIN/SNOW SHOWERS WITH SPOTTY BRIEF PERIODS OF FREEZING
PRECIP AROUND DAYBREAK TUE ACROSS N CT/N RI INTO S CENTRAL MA.
EXPECT HIGH TEMPS ON TUE TO RUN ABOUT 5 DEGS ABOVE SEASONAL NORMS
AS WINDS BEGIN TO SHIFT MORE S- SE...THOUGH SOME TIMING ISSUES IN
PLACE FOR WIND SHIFT AMONGST OP MODELS.

ONCE THE LOW EXITS LATE TUE...WILL ALREADY START TO SEE MOISTURE
FEED UP THE COAST FROM THE DEVELOPING GULF LOW...SO NOT MUCH OF A
BREAK IN THE PRECIP BETWEEN SYSTEMS.

TUESDAY/S LATE MORNING HIGH TIDE WILL RUN UP TO 11.6 FT IN BOSTON
AND...WITH ANY EASTERLY WIND FLOW...THIS MAY CAUSE MINOR COASTAL
FLOODING. WILL MONITOR THIS ASPECT.

WEDNESDAY AND CHRISTMAS DAY...HIGH CONFIDENCE IN SYSTEM...LOW
CONFIDENCE ON DETAILS.

SECONDARY LOW FROM THE PARENT OVER THE NORTHERN GREAT LAKES
DEEPENS AS IT SHIFTS N. MODELS TRY TO PUSH THIS SYSTEM CLOSE TO OR
JUST INTO WESTERN NEW ENGLAND LATE WED/WED NIGHT...THOUGH STILL
TIMING ISSUES IN PLACE. AT THIS POINT...WILL SEE HEAVIEST SLUG OF
PRECIP MOVING ACROSS LATE WED INTO WED EVENING. GOOD TROPICAL
CONNECTION CONTINUES WITH PWATS FROM 1.25 TO 1.4 INCHES...RUNNING
ABOUT +2SD TO +3SD ABOVE NORMAL FOR LATE DECEMBER. GOOD SHOT OF
MILD AIR WORKS IN ON SE-S WINDS. MODELS CONTINUE TO SIGNAL H925
AND H85 FROM 50-65 KT...AND AT LEAST SOME WILL MIX DOWN ESPECIALLY
IF THE LOW PRES PASSES CLOSER /WITH RAPIDLY FALLING PRESSURE/.
HAVE HIGHS ON WED UP TO THE LOWER 50S ACROSS EASTERN AND SOUTHERN
AREAS...BUT COULD BE EVEN HIGHER WITH STRONG ONSHORE WINDS.

CURRENT TIMING SUGGESTS THE DRY SLOT SHOULD WORK INTO THE REGION
LATE WED NIGHT INTO CHRISTMAS MORNING...SO PRECIP SHOULD END. WILL
STILL SEE GUSTY WINDS...THOUGH QUICKLY SHIFTING TO W-SW AND
GUSTING UP TO 25-30 KT...HIGHEST ALONG THE S COAST.

MAY NEED HEADLINES WITH THIS SYSTEM...WITH POSSIBLE URBAN/POOR
DRAINAGE FLOODING IN HEAVY RAINFALL WED/WED NIGHT...STRONG WINDS
BOTH WED AND THU...AND MAYBE EVEN FOR COASTAL CONCERNS. NOTING
ASTRO HIGH TIDES CONTINUE /11.7 AND 11.5 FT AT BOSTON
RESPECTIVELY/... THOUGH TIMING OF WIND SHIFT MAY COME INTO PLAY
FOR CHRISTMAS EVE INTO CHRISTMAS MORNING.

FRIDAY...LOW CONFIDENCE MAINLY FOR TIMING.
ONCE UPPER LOW MOVES INTO SOUTHERN CANADA...EXPECT A RATHER FAST
UPPER W FLOW IN PLACE. MAY SEE LEFTOVER SNOW SHOWERS ACROSS THE E
SLOPES OF THE BERKSHIRES INTO THE MONADNOCKS. TEMPS WILL FALL BACK
CLOSE TO SEASONAL NORMS. ANOTHER LOW MIGHT MOVE INTO W NY STATE
FRI NIGHT.

&&

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

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

SHORT TERM /TODAY THROUGH FRIDAY NIGHT/...

THROUGH 00Z...LOW VFR/MVFR CIGS AROUND 3000-3500 FT. TREND SHOULD
BE FOR CLOUD DECK TO BECOME SCT TOWARD 00Z..ESPECIALLY NEAR THE
COAST. W/NW GUSTS TO 25-30 KT.

TONIGHT...MODERATE CONFIDENCE. MAINLY VFR...BUT LINGERING MVFR
CIGS ACROSS N CENTRAL-NW MA AND HIGHER TERRAIN THROUGH 03Z OR SO.
DIMINISHING WIND.

FRIDAY...LOW CONFIDENCE DUE TO UNCERTAINTY WITH EXTENT OF ANY MVFR
CIGS. WE HAVE MAINLY VFR IN THE TAFS WITH POCKETS OF MVFR...BUT
IT IS POSSIBLE MVFR CIGS COULD BE MORE EXPANSIVE IF LOW LEVEL
MOISTURE BECOMES TRAPPED BELOW THE INVERSION. LATER FORECASTS
WILL NEED TO REEVALUATE THIS.

FRIDAY NIGHT...MODERATE CONFIDENCE. MAINLY VFR...BUT MVFR CIGS
FROM THE OCEAN EXPANDING WEST ACROSS E MA. LOW PROB FOR SOME OCEAN
EFFECT SNOW SHOWERS OVER CAPE COD AND ACK AFTER MIDNIGHT.

KBOS TERMINAL...MODERATE CONFIDENCE. MAINLY VFR...BUT LOW PROB
FOR MVFR CIGS FRIDAY.

KBDL TERMINAL...MODERATE CONFIDENCE. SHOULD SEE MVFR CIGS SCATTER
OUT THIS EVENING. MVFR CIGS MAY RETURN FRI BUT THIS IS UNCERTAIN.

OUTLOOK...SATURDAY THROUGH TUESDAY...

SATURDAY INTO SUNDAY...HIGH CONFIDENCE. MAINLY VFR ACROSS CENTRAL
AND WESTERN AREAS. E MA INTO RI...AREAS MVFR CIGS/VSBYS IN ANY
RAIN/SNOW SHOWERS...AREAS OF DRIZZLE SAT NIGHT INTO SUN MORNING.

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 FRIDAY NIGHT/...HIGH CONFIDENCE.

TONIGHT...W/NW GUSTS 25-30 KT WILL LINGER OVER THE WATERS INTO
THIS EVENING BEFORE DIMINISHING OVERNIGHT. SCA HEADLINES WILL
CONTINUE TONIGHT.

FRIDAY...NW WINDS WILL BE BELOW SCA THRESHOLDS...BUT HAZARDOUS
SEAS WILL CONTINUE THROUGH THE MORNING OVER THE OUTER EASTERN
WATERS...BEFORE SUBSIDING BELOW SCA. WILL LIKELY NEED TO EXTEND
THE SCA FOR SEAS INTO FRI MORNING.

FRIDAY NIGHT...N/NW WINDS AND SEAS BELOW SCA.

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.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 AM EST FRIDAY FOR ANZ231-232-251.
     SMALL CRAFT ADVISORY UNTIL 11 PM EST THIS EVENING FOR
     ANZ233>235-237.
     SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR ANZ230-
     236.
     SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ250-254>256.

&&

$$
SYNOPSIS...KJC/EVT
NEAR TERM...KJC/EVT
SHORT TERM...KJC
LONG TERM...EVT
AVIATION...KJC/EVT
MARINE...KJC/EVT



000
FXUS61 KBOX 190006
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
706 PM EST THU DEC 18 2014

.SYNOPSIS...
DRY AND SEASONABLE CONDITIONS WILL PREVAIL FRIDAY. AN UPPER LEVEL
DISTURBANCE AND MOIST NORTHEAST FLOW WILL BRING SOME LIGHT
PRECIPITATION SATURDAY INTO SUNDAY. LOW PRESSURE WILL LIKELY PASS
WELL SOUTH OF THE REGION TUESDAY...BUT STILL COULD BRING A PERIOD
OF LIGHT PRECIPITATION. A MUCH STRONGER STORM IS LIKELY TO BRING
HEAVY RAIN AND WIND TO SOUTHERN NEW ENGLAND WEDNESDAY INTO
WEDNESDAY EVENING. DRY BUT VERY WINDY CONDITIONS FOLLOW FOR
CHRISTMAS DAY.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
650 PM UPDATE...
NOTING SOME BREAKS IN THE CLOUDS ON LATEST IR SATELLITE IMAGERY
BUT SURFACE OBS SHOWING LOW BKN-OVC WHICH ARE TOUGH TO PICK UP ON
THE IR. TEMPS REMAIN IN THE MID 30S TO LOWER 40S AT 23Z AND 00Z
WITH STEADY W-NW WINDS.

FORECAST IN PRETTY GOOD SHAPE...THOUGH DID UPDATE THE NEAR TERM TO
BRING CURRENT.

PREVIOUS DISCUSSION...
LOW PRES MOVES NE FROM THE MARITIMES BUT CYCLONIC FLOW WILL
PERSIST ALONG WITH SOME MOISTURE IN THE COLUMN WHICH WILL KEEP A
FEW CLOUDS ACROSS THE REGION ALTHOUGH DRY WEATHER EXPECTED. WHILE
GUSTY WINDS WILL DIMINISH TONIGHT...THERE IS ENOUGH PRESSURE
GRADIENT TO KEEP THE WINDS UP SO TEMPS WILL NOT DROP OFF THAT
QUICKLY. USED A BLEND OF AVAILABLE GUIDANCE WHICH SUGGESTS MIN
TEMPS MOSTLY IN THE 20S...WITH LOWER 30S OVER THE OUTER
CAPE/ISLANDS.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
FRIDAY...
HIGH PRES BUILDS ACROSS THE GRT LAKES WITH NW FLOW ACROSS NEW
ENG. TRICKY CLOUD FORECAST AS NAM INDICATING LOW LEVEL MOISTURE
TRAPPED BELOW INVERSION WITH WIDESPREAD LOW CLOUDS...WHILE GFS AND
ECMWF ARE DRIER IN THE LOW LEVELS. GIVEN LOW LEVEL FLOW IS STILL
NW...WE WILL LEAN MORE OPTIMISTIC THAN NAM WITH A MIX OF CLOUDS
AND SUN EXPECTED. TEMPS WILL LIKELY BE 3-5 DEGREES COLDER THAN
TODAY GIVEN COOLING AT 925 MB...WITH MAX TEMPS RANGING FROM NEAR
30 HIGHER TERRAIN IN NORTHERN AND WESTERN MA TO UPPER 30S IN THE
COASTAL PLAIN.

FRIDAY NIGHT...
MID LEVEL SHORTWAVE MOVES INTO W NEW ENG TOWARD DAYBREAK...BUT
FORCING IS WEAK THROUGH MOST OF THE NIGHT AND MOISTURE IS LIMITED
SO EXPECTING A MAINLY DRY NIGHT. HOWEVER...AS HIGH PRES BUILDS
EASTWARD ACROSS QUEBEC LOW LEVEL WINDS BECOME NE AND MODELS
INDICATE INCREASING LOW MOISTURE BACKING IN ACROSS SE NEW ENG
OVERNIGHT. DELTA T FROM SST TO THE TOP OF THE MIXED LAYER IS
AROUND 13C WHICH IS MARGINAL FOR OCEAN EFFECT AND OCEAN INDUCED
CAPES ARE NOT IMPRESSIVE...BUT LOW LEVEL LAPSE RATES ARE
INCREASING. MODELS DO SHOW SOME LIGHT QPF DEVELOPING SO THERE MAY
BE A FEW SNOW SHOWERS DEVELOPING OVER CAPE COD AND ACK OVERNIGHT
AND WE HAVE SOME LOW CHC POPS.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
HIGHLIGHTS...

* SCT LIGHT SNOW/RAIN SHOWERS SAT INTO SUN...WITH A PERIOD OF
  DRIZZLE/FREEZING DRIZZLE POSSIBLE SAT NIGHT INTO SUN MORNING
* WEAK WAVE OF LOW PRESSURE WILL PASS WELL OFFSHORE TUE BUT COULD
  STILL SEE LIGHT PRECIP
* ANOMALOUSLY STRONG STORM SYSTEM WILL BRING HEAVY RAIN...GUSTY
  WINDS AND COASTAL CONCERNS AROUND CHRISTMAS EVE

OVERVIEW AND MODEL PREFERENCES...
MEDIUM RANGE MODELS CONTINUE IN PRETTY GOOD AGREEMENT ON LARGE
SCALE AND UPPER LEVEL FEATURES THROUGH MOST OF THE FORECAST
PERIOD.

MODELS AND ENSEMBLES CONTINUE TO SIGNAL WEAK SHORT WAVES THAT
TRANSLATE ACROSS THE REGION EARLY IN THIS PERIOD...WITH A RATHER
POTENT BUT FAST MOVING ONE FOR SAT NIGHT/SUN TIMEFRAME WHICH IS
AIDED WITH LOW LEVEL ONSHORE MOISTURE...WITH A SECOND WEAK LOW FOR
LATE MON INTO TUE BRINGING ANOTHER PERIOD OF LIGHT PRECIP.

STILL QUITE A FEW PLACEMENT AND TIMING ISSUES WITH THE EVOLUTION
OF AN ANOMALOUSLY DEEP H5 CUTOFF LOW DEVELOPING ACROSS THE WESTERN
GREAT LAKES AROUND THE MON-TUE TIMEFRAME...THEN ROTATES NE
SOMEWHERE ACROSS S CENTRAL CANADA ON CHRISTMAS DAY. BIG
IMPLICATIONS WITH THE ASSOCIATED LONG WAVE TROUGH. GUIDANCE
CONTINUES TO INDICATE THE TROUGH BECOMING NEGATIVELY TILTED ACROSS
THE MID ATLC OR SE U.S. LATE IN THIS PERIOD. SECONDARY/ TRIPLE
POINT LOW FORMS ON SURFACE FRONT OVER THE EASTERN GULF AROUND
TUESDAY...THEN WORKS UP ACROSS EASTERN PORTIONS OF THE SE AND MID
ATLC STATES. QUESTION IS IF THIS LOW APPROACHES WESTERN PORTIONS
OF NEW ENGLAND WED NIGHT.

STILL SEE THE SIGNALS FOR A FAST MOVING STORM WITH MULTIPLE
IMPACTS POSSIBLE...INCLUDING PERIOD OF HEAVY RAINFALL AND STRONG
WIND GUSTS...FIRST FROM THE SOUTH THEN SHIFTING TO THE WEST. COULD
EVEN SEE SOME COASTAL IMPACTS DURING THE HIGH TIDE CYCLE DURING
WED. TIMING REMAINS AN ISSUE...AS ONE WOULD EXPECT THIS FAR OUT.
MODEL GUIDANCE STILL DOING A RATHER GOOD JOB HANDLING GENERAL
FEATURES OF THIS SYSTEM AT THIS POINT.

USED A BLEND OF THE AVAILABLE GUIDANCE ALONG WITH WPC GUIDANCE.

DETAILS...

SATURDAY INTO SUNDAY...HIGH CONFIDENCE.
HIGH PRES AT THE SURFACE AND ALOFT MOVES ACROSS QUEBEC INTO THE
MARITIMES DURING THIS WEEKEND...THEN TENDS TO SLOW ITS EASTWARD
PROGRESS WITH BLOCKING OVER THE WESTERN ATLC. RATHER POTENT SHORT
WAVE UNDERNEATH THE UPPER SYSTEM MOVES ACROSS THE REGION...AIDED
BY A LOW LEVEL E-NE WIND IN PLACE. A LOT OF LOW LEVEL MOISTURE IN
PLACE AS SEEN ON BUFKIT MODEL SOUNDINGS...SO WILL SEE SOME LIGHT
RAIN/SNOW SHOWERS DEVELOP FROM E-W DURING SATURDAY. EXPECTING
LITTLE IF ANY SNOW ACCUMULATIONS DURING SAT.

HOWEVER...AS TEMPS FALL BACK SAT NIGHT...ALONG WITH THE DEEP LOW
LEVEL MOISTURE FEED...WILL ALSO SEE AREAS OF DRIZZLE DEVELOP. BIG
PROBLEM WILL BE JUST AWAY FROM THE COAST WHERE TEMPS FALL BELOW
FREEZING WHICH MAY MEAN FREEZING DRIZZLE. DOES NOT TAKE MUCH TO
GET GLAZING ESPECIALLY ON UNTREATED SURFACES. WILL NEED TO MONITOR
THIS CLOSELY FOR POSSIBLE WINTER WEATHER HEADLINES ACROSS INTERIOR
E MA INTO RI...POSSIBLY EVEN FURTHER W. WITH THE LIGHT
SNOW...MIGHT SEE UP TO 1/2 INCH ACCUMULATIONS SAT NIGHT INTO SUN
MORNING.

ON SUNDAY...DRIZZLE WILL TAPER OFF DURING THE MORNING...THOUGH
LEFTOVER RAIN/SNOW SHOWERS WILL LINGER THOUGH TEND TO TAPER OFF
DURING THE AFTERNOON.

MONDAY INTO TUESDAY...MODERATE CONFIDENCE.
ANOTHER COASTAL LOW LOOKS TO DEVELOP OFF THE SE U.S. COAST
AND...AS UPPER LEVEL TROUGH BEGINS TO DIG ACROSS THE CENTRAL
U.S...WILL SHIFT TO THE E-NE UNDERNEATH THE UPPER RIDGE. THE
MARITIMES SURFACE HIGH REMAINS PRETTY MUCH IN PLACE...WHICH WILL
HELP SHIFT THE MAIN EFFECTS OF THIS LOW WELL OFFSHORE /SE OF THE
40N/70W BENCHMARK/. HOWEVER...MODELS CONTINUE TO SIGNAL LIGHT
PRECIP REACHING THE COAST MAINLY MON NIGHT INTO TUE. EXPECT MAINLY
MIXED RAIN/SNOW SHOWERS WITH SPOTTY BRIEF PERIODS OF FREEZING
PRECIP AROUND DAYBREAK TUE ACROSS N CT/N RI INTO S CENTRAL MA.
EXPECT HIGH TEMPS ON TUE TO RUN ABOUT 5 DEGS ABOVE SEASONAL NORMS
AS WINDS BEGIN TO SHIFT MORE S- SE...THOUGH SOME TIMING ISSUES IN
PLACE FOR WIND SHIFT AMONGST OP MODELS.

ONCE THE LOW EXITS LATE TUE...WILL ALREADY START TO SEE MOISTURE
FEED UP THE COAST FROM THE DEVELOPING GULF LOW...SO NOT MUCH OF A
BREAK IN THE PRECIP BETWEEN SYSTEMS.

TUESDAY/S LATE MORNING HIGH TIDE WILL RUN UP TO 11.6 FT IN BOSTON
AND...WITH ANY EASTERLY WIND FLOW...THIS MAY CAUSE MINOR COASTAL
FLOODING. WILL MONITOR THIS ASPECT.

WEDNESDAY AND CHRISTMAS DAY...HIGH CONFIDENCE IN SYSTEM...LOW
CONFIDENCE ON DETAILS.

SECONDARY LOW FROM THE PARENT OVER THE NORTHERN GREAT LAKES
DEEPENS AS IT SHIFTS N. MODELS TRY TO PUSH THIS SYSTEM CLOSE TO OR
JUST INTO WESTERN NEW ENGLAND LATE WED/WED NIGHT...THOUGH STILL
TIMING ISSUES IN PLACE. AT THIS POINT...WILL SEE HEAVIEST SLUG OF
PRECIP MOVING ACROSS LATE WED INTO WED EVENING. GOOD TROPICAL
CONNECTION CONTINUES WITH PWATS FROM 1.25 TO 1.4 INCHES...RUNNING
ABOUT +2SD TO +3SD ABOVE NORMAL FOR LATE DECEMBER. GOOD SHOT OF
MILD AIR WORKS IN ON SE-S WINDS. MODELS CONTINUE TO SIGNAL H925
AND H85 FROM 50-65 KT...AND AT LEAST SOME WILL MIX DOWN ESPECIALLY
IF THE LOW PRES PASSES CLOSER /WITH RAPIDLY FALLING PRESSURE/.
HAVE HIGHS ON WED UP TO THE LOWER 50S ACROSS EASTERN AND SOUTHERN
AREAS...BUT COULD BE EVEN HIGHER WITH STRONG ONSHORE WINDS.

CURRENT TIMING SUGGESTS THE DRY SLOT SHOULD WORK INTO THE REGION
LATE WED NIGHT INTO CHRISTMAS MORNING...SO PRECIP SHOULD END. WILL
STILL SEE GUSTY WINDS...THOUGH QUICKLY SHIFTING TO W-SW AND
GUSTING UP TO 25-30 KT...HIGHEST ALONG THE S COAST.

MAY NEED HEADLINES WITH THIS SYSTEM...WITH POSSIBLE URBAN/POOR
DRAINAGE FLOODING IN HEAVY RAINFALL WED/WED NIGHT...STRONG WINDS
BOTH WED AND THU...AND MAYBE EVEN FOR COASTAL CONCERNS. NOTING
ASTRO HIGH TIDES CONTINUE /11.7 AND 11.5 FT AT BOSTON
RESPECTIVELY/... THOUGH TIMING OF WIND SHIFT MAY COME INTO PLAY
FOR CHRISTMAS EVE INTO CHRISTMAS MORNING.

FRIDAY...LOW CONFIDENCE MAINLY FOR TIMING.
ONCE UPPER LOW MOVES INTO SOUTHERN CANADA...EXPECT A RATHER FAST
UPPER W FLOW IN PLACE. MAY SEE LEFTOVER SNOW SHOWERS ACROSS THE E
SLOPES OF THE BERKSHIRES INTO THE MONADNOCKS. TEMPS WILL FALL BACK
CLOSE TO SEASONAL NORMS. ANOTHER LOW MIGHT MOVE INTO W NY STATE
FRI NIGHT.

&&

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

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

SHORT TERM /TODAY THROUGH FRIDAY NIGHT/...

THROUGH 00Z...LOW VFR/MVFR CIGS AROUND 3000-3500 FT. TREND SHOULD
BE FOR CLOUD DECK TO BECOME SCT TOWARD 00Z..ESPECIALLY NEAR THE
COAST. W/NW GUSTS TO 25-30 KT.

TONIGHT...MODERATE CONFIDENCE. MAINLY VFR...BUT LINGERING MVFR
CIGS ACROSS N CENTRAL-NW MA AND HIGHER TERRAIN THROUGH 03Z OR SO.
DIMINISHING WIND.

FRIDAY...LOW CONFIDENCE DUE TO UNCERTAINTY WITH EXTENT OF ANY MVFR
CIGS. WE HAVE MAINLY VFR IN THE TAFS WITH POCKETS OF MVFR...BUT
IT IS POSSIBLE MVFR CIGS COULD BE MORE EXPANSIVE IF LOW LEVEL
MOISTURE BECOMES TRAPPED BELOW THE INVERSION. LATER FORECASTS
WILL NEED TO REEVALUATE THIS.

FRIDAY NIGHT...MODERATE CONFIDENCE. MAINLY VFR...BUT MVFR CIGS
FROM THE OCEAN EXPANDING WEST ACROSS E MA. LOW PROB FOR SOME OCEAN
EFFECT SNOW SHOWERS OVER CAPE COD AND ACK AFTER MIDNIGHT.

KBOS TERMINAL...MODERATE CONFIDENCE. MAINLY VFR...BUT LOW PROB
FOR MVFR CIGS FRIDAY.

KBDL TERMINAL...MODERATE CONFIDENCE. SHOULD SEE MVFR CIGS SCATTER
OUT THIS EVENING. MVFR CIGS MAY RETURN FRI BUT THIS IS UNCERTAIN.

OUTLOOK...SATURDAY THROUGH TUESDAY...

SATURDAY INTO SUNDAY...HIGH CONFIDENCE. MAINLY VFR ACROSS CENTRAL
AND WESTERN AREAS. E MA INTO RI...AREAS MVFR CIGS/VSBYS IN ANY
RAIN/SNOW SHOWERS...AREAS OF DRIZZLE SAT NIGHT INTO SUN MORNING.

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 FRIDAY NIGHT/...HIGH CONFIDENCE.

TONIGHT...W/NW GUSTS 25-30 KT WILL LINGER OVER THE WATERS INTO
THIS EVENING BEFORE DIMINISHING OVERNIGHT. SCA HEADLINES WILL
CONTINUE TONIGHT.

FRIDAY...NW WINDS WILL BE BELOW SCA THRESHOLDS...BUT HAZARDOUS
SEAS WILL CONTINUE THROUGH THE MORNING OVER THE OUTER EASTERN
WATERS...BEFORE SUBSIDING BELOW SCA. WILL LIKELY NEED TO EXTEND
THE SCA FOR SEAS INTO FRI MORNING.

FRIDAY NIGHT...N/NW WINDS AND SEAS BELOW SCA.

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.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 AM EST FRIDAY FOR ANZ231-232-251.
     SMALL CRAFT ADVISORY UNTIL 11 PM EST THIS EVENING FOR
     ANZ233>235-237.
     SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR ANZ230-
     236.
     SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ250-254>256.

&&

$$
SYNOPSIS...KJC/EVT
NEAR TERM...KJC/EVT
SHORT TERM...KJC
LONG TERM...EVT
AVIATION...KJC/EVT
MARINE...KJC/EVT



000
FXUS61 KBOX 190006
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
706 PM EST THU DEC 18 2014

.SYNOPSIS...
DRY AND SEASONABLE CONDITIONS WILL PREVAIL FRIDAY. AN UPPER LEVEL
DISTURBANCE AND MOIST NORTHEAST FLOW WILL BRING SOME LIGHT
PRECIPITATION SATURDAY INTO SUNDAY. LOW PRESSURE WILL LIKELY PASS
WELL SOUTH OF THE REGION TUESDAY...BUT STILL COULD BRING A PERIOD
OF LIGHT PRECIPITATION. A MUCH STRONGER STORM IS LIKELY TO BRING
HEAVY RAIN AND WIND TO SOUTHERN NEW ENGLAND WEDNESDAY INTO
WEDNESDAY EVENING. DRY BUT VERY WINDY CONDITIONS FOLLOW FOR
CHRISTMAS DAY.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
650 PM UPDATE...
NOTING SOME BREAKS IN THE CLOUDS ON LATEST IR SATELLITE IMAGERY
BUT SURFACE OBS SHOWING LOW BKN-OVC WHICH ARE TOUGH TO PICK UP ON
THE IR. TEMPS REMAIN IN THE MID 30S TO LOWER 40S AT 23Z AND 00Z
WITH STEADY W-NW WINDS.

FORECAST IN PRETTY GOOD SHAPE...THOUGH DID UPDATE THE NEAR TERM TO
BRING CURRENT.

PREVIOUS DISCUSSION...
LOW PRES MOVES NE FROM THE MARITIMES BUT CYCLONIC FLOW WILL
PERSIST ALONG WITH SOME MOISTURE IN THE COLUMN WHICH WILL KEEP A
FEW CLOUDS ACROSS THE REGION ALTHOUGH DRY WEATHER EXPECTED. WHILE
GUSTY WINDS WILL DIMINISH TONIGHT...THERE IS ENOUGH PRESSURE
GRADIENT TO KEEP THE WINDS UP SO TEMPS WILL NOT DROP OFF THAT
QUICKLY. USED A BLEND OF AVAILABLE GUIDANCE WHICH SUGGESTS MIN
TEMPS MOSTLY IN THE 20S...WITH LOWER 30S OVER THE OUTER
CAPE/ISLANDS.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
FRIDAY...
HIGH PRES BUILDS ACROSS THE GRT LAKES WITH NW FLOW ACROSS NEW
ENG. TRICKY CLOUD FORECAST AS NAM INDICATING LOW LEVEL MOISTURE
TRAPPED BELOW INVERSION WITH WIDESPREAD LOW CLOUDS...WHILE GFS AND
ECMWF ARE DRIER IN THE LOW LEVELS. GIVEN LOW LEVEL FLOW IS STILL
NW...WE WILL LEAN MORE OPTIMISTIC THAN NAM WITH A MIX OF CLOUDS
AND SUN EXPECTED. TEMPS WILL LIKELY BE 3-5 DEGREES COLDER THAN
TODAY GIVEN COOLING AT 925 MB...WITH MAX TEMPS RANGING FROM NEAR
30 HIGHER TERRAIN IN NORTHERN AND WESTERN MA TO UPPER 30S IN THE
COASTAL PLAIN.

FRIDAY NIGHT...
MID LEVEL SHORTWAVE MOVES INTO W NEW ENG TOWARD DAYBREAK...BUT
FORCING IS WEAK THROUGH MOST OF THE NIGHT AND MOISTURE IS LIMITED
SO EXPECTING A MAINLY DRY NIGHT. HOWEVER...AS HIGH PRES BUILDS
EASTWARD ACROSS QUEBEC LOW LEVEL WINDS BECOME NE AND MODELS
INDICATE INCREASING LOW MOISTURE BACKING IN ACROSS SE NEW ENG
OVERNIGHT. DELTA T FROM SST TO THE TOP OF THE MIXED LAYER IS
AROUND 13C WHICH IS MARGINAL FOR OCEAN EFFECT AND OCEAN INDUCED
CAPES ARE NOT IMPRESSIVE...BUT LOW LEVEL LAPSE RATES ARE
INCREASING. MODELS DO SHOW SOME LIGHT QPF DEVELOPING SO THERE MAY
BE A FEW SNOW SHOWERS DEVELOPING OVER CAPE COD AND ACK OVERNIGHT
AND WE HAVE SOME LOW CHC POPS.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
HIGHLIGHTS...

* SCT LIGHT SNOW/RAIN SHOWERS SAT INTO SUN...WITH A PERIOD OF
  DRIZZLE/FREEZING DRIZZLE POSSIBLE SAT NIGHT INTO SUN MORNING
* WEAK WAVE OF LOW PRESSURE WILL PASS WELL OFFSHORE TUE BUT COULD
  STILL SEE LIGHT PRECIP
* ANOMALOUSLY STRONG STORM SYSTEM WILL BRING HEAVY RAIN...GUSTY
  WINDS AND COASTAL CONCERNS AROUND CHRISTMAS EVE

OVERVIEW AND MODEL PREFERENCES...
MEDIUM RANGE MODELS CONTINUE IN PRETTY GOOD AGREEMENT ON LARGE
SCALE AND UPPER LEVEL FEATURES THROUGH MOST OF THE FORECAST
PERIOD.

MODELS AND ENSEMBLES CONTINUE TO SIGNAL WEAK SHORT WAVES THAT
TRANSLATE ACROSS THE REGION EARLY IN THIS PERIOD...WITH A RATHER
POTENT BUT FAST MOVING ONE FOR SAT NIGHT/SUN TIMEFRAME WHICH IS
AIDED WITH LOW LEVEL ONSHORE MOISTURE...WITH A SECOND WEAK LOW FOR
LATE MON INTO TUE BRINGING ANOTHER PERIOD OF LIGHT PRECIP.

STILL QUITE A FEW PLACEMENT AND TIMING ISSUES WITH THE EVOLUTION
OF AN ANOMALOUSLY DEEP H5 CUTOFF LOW DEVELOPING ACROSS THE WESTERN
GREAT LAKES AROUND THE MON-TUE TIMEFRAME...THEN ROTATES NE
SOMEWHERE ACROSS S CENTRAL CANADA ON CHRISTMAS DAY. BIG
IMPLICATIONS WITH THE ASSOCIATED LONG WAVE TROUGH. GUIDANCE
CONTINUES TO INDICATE THE TROUGH BECOMING NEGATIVELY TILTED ACROSS
THE MID ATLC OR SE U.S. LATE IN THIS PERIOD. SECONDARY/ TRIPLE
POINT LOW FORMS ON SURFACE FRONT OVER THE EASTERN GULF AROUND
TUESDAY...THEN WORKS UP ACROSS EASTERN PORTIONS OF THE SE AND MID
ATLC STATES. QUESTION IS IF THIS LOW APPROACHES WESTERN PORTIONS
OF NEW ENGLAND WED NIGHT.

STILL SEE THE SIGNALS FOR A FAST MOVING STORM WITH MULTIPLE
IMPACTS POSSIBLE...INCLUDING PERIOD OF HEAVY RAINFALL AND STRONG
WIND GUSTS...FIRST FROM THE SOUTH THEN SHIFTING TO THE WEST. COULD
EVEN SEE SOME COASTAL IMPACTS DURING THE HIGH TIDE CYCLE DURING
WED. TIMING REMAINS AN ISSUE...AS ONE WOULD EXPECT THIS FAR OUT.
MODEL GUIDANCE STILL DOING A RATHER GOOD JOB HANDLING GENERAL
FEATURES OF THIS SYSTEM AT THIS POINT.

USED A BLEND OF THE AVAILABLE GUIDANCE ALONG WITH WPC GUIDANCE.

DETAILS...

SATURDAY INTO SUNDAY...HIGH CONFIDENCE.
HIGH PRES AT THE SURFACE AND ALOFT MOVES ACROSS QUEBEC INTO THE
MARITIMES DURING THIS WEEKEND...THEN TENDS TO SLOW ITS EASTWARD
PROGRESS WITH BLOCKING OVER THE WESTERN ATLC. RATHER POTENT SHORT
WAVE UNDERNEATH THE UPPER SYSTEM MOVES ACROSS THE REGION...AIDED
BY A LOW LEVEL E-NE WIND IN PLACE. A LOT OF LOW LEVEL MOISTURE IN
PLACE AS SEEN ON BUFKIT MODEL SOUNDINGS...SO WILL SEE SOME LIGHT
RAIN/SNOW SHOWERS DEVELOP FROM E-W DURING SATURDAY. EXPECTING
LITTLE IF ANY SNOW ACCUMULATIONS DURING SAT.

HOWEVER...AS TEMPS FALL BACK SAT NIGHT...ALONG WITH THE DEEP LOW
LEVEL MOISTURE FEED...WILL ALSO SEE AREAS OF DRIZZLE DEVELOP. BIG
PROBLEM WILL BE JUST AWAY FROM THE COAST WHERE TEMPS FALL BELOW
FREEZING WHICH MAY MEAN FREEZING DRIZZLE. DOES NOT TAKE MUCH TO
GET GLAZING ESPECIALLY ON UNTREATED SURFACES. WILL NEED TO MONITOR
THIS CLOSELY FOR POSSIBLE WINTER WEATHER HEADLINES ACROSS INTERIOR
E MA INTO RI...POSSIBLY EVEN FURTHER W. WITH THE LIGHT
SNOW...MIGHT SEE UP TO 1/2 INCH ACCUMULATIONS SAT NIGHT INTO SUN
MORNING.

ON SUNDAY...DRIZZLE WILL TAPER OFF DURING THE MORNING...THOUGH
LEFTOVER RAIN/SNOW SHOWERS WILL LINGER THOUGH TEND TO TAPER OFF
DURING THE AFTERNOON.

MONDAY INTO TUESDAY...MODERATE CONFIDENCE.
ANOTHER COASTAL LOW LOOKS TO DEVELOP OFF THE SE U.S. COAST
AND...AS UPPER LEVEL TROUGH BEGINS TO DIG ACROSS THE CENTRAL
U.S...WILL SHIFT TO THE E-NE UNDERNEATH THE UPPER RIDGE. THE
MARITIMES SURFACE HIGH REMAINS PRETTY MUCH IN PLACE...WHICH WILL
HELP SHIFT THE MAIN EFFECTS OF THIS LOW WELL OFFSHORE /SE OF THE
40N/70W BENCHMARK/. HOWEVER...MODELS CONTINUE TO SIGNAL LIGHT
PRECIP REACHING THE COAST MAINLY MON NIGHT INTO TUE. EXPECT MAINLY
MIXED RAIN/SNOW SHOWERS WITH SPOTTY BRIEF PERIODS OF FREEZING
PRECIP AROUND DAYBREAK TUE ACROSS N CT/N RI INTO S CENTRAL MA.
EXPECT HIGH TEMPS ON TUE TO RUN ABOUT 5 DEGS ABOVE SEASONAL NORMS
AS WINDS BEGIN TO SHIFT MORE S- SE...THOUGH SOME TIMING ISSUES IN
PLACE FOR WIND SHIFT AMONGST OP MODELS.

ONCE THE LOW EXITS LATE TUE...WILL ALREADY START TO SEE MOISTURE
FEED UP THE COAST FROM THE DEVELOPING GULF LOW...SO NOT MUCH OF A
BREAK IN THE PRECIP BETWEEN SYSTEMS.

TUESDAY/S LATE MORNING HIGH TIDE WILL RUN UP TO 11.6 FT IN BOSTON
AND...WITH ANY EASTERLY WIND FLOW...THIS MAY CAUSE MINOR COASTAL
FLOODING. WILL MONITOR THIS ASPECT.

WEDNESDAY AND CHRISTMAS DAY...HIGH CONFIDENCE IN SYSTEM...LOW
CONFIDENCE ON DETAILS.

SECONDARY LOW FROM THE PARENT OVER THE NORTHERN GREAT LAKES
DEEPENS AS IT SHIFTS N. MODELS TRY TO PUSH THIS SYSTEM CLOSE TO OR
JUST INTO WESTERN NEW ENGLAND LATE WED/WED NIGHT...THOUGH STILL
TIMING ISSUES IN PLACE. AT THIS POINT...WILL SEE HEAVIEST SLUG OF
PRECIP MOVING ACROSS LATE WED INTO WED EVENING. GOOD TROPICAL
CONNECTION CONTINUES WITH PWATS FROM 1.25 TO 1.4 INCHES...RUNNING
ABOUT +2SD TO +3SD ABOVE NORMAL FOR LATE DECEMBER. GOOD SHOT OF
MILD AIR WORKS IN ON SE-S WINDS. MODELS CONTINUE TO SIGNAL H925
AND H85 FROM 50-65 KT...AND AT LEAST SOME WILL MIX DOWN ESPECIALLY
IF THE LOW PRES PASSES CLOSER /WITH RAPIDLY FALLING PRESSURE/.
HAVE HIGHS ON WED UP TO THE LOWER 50S ACROSS EASTERN AND SOUTHERN
AREAS...BUT COULD BE EVEN HIGHER WITH STRONG ONSHORE WINDS.

CURRENT TIMING SUGGESTS THE DRY SLOT SHOULD WORK INTO THE REGION
LATE WED NIGHT INTO CHRISTMAS MORNING...SO PRECIP SHOULD END. WILL
STILL SEE GUSTY WINDS...THOUGH QUICKLY SHIFTING TO W-SW AND
GUSTING UP TO 25-30 KT...HIGHEST ALONG THE S COAST.

MAY NEED HEADLINES WITH THIS SYSTEM...WITH POSSIBLE URBAN/POOR
DRAINAGE FLOODING IN HEAVY RAINFALL WED/WED NIGHT...STRONG WINDS
BOTH WED AND THU...AND MAYBE EVEN FOR COASTAL CONCERNS. NOTING
ASTRO HIGH TIDES CONTINUE /11.7 AND 11.5 FT AT BOSTON
RESPECTIVELY/... THOUGH TIMING OF WIND SHIFT MAY COME INTO PLAY
FOR CHRISTMAS EVE INTO CHRISTMAS MORNING.

FRIDAY...LOW CONFIDENCE MAINLY FOR TIMING.
ONCE UPPER LOW MOVES INTO SOUTHERN CANADA...EXPECT A RATHER FAST
UPPER W FLOW IN PLACE. MAY SEE LEFTOVER SNOW SHOWERS ACROSS THE E
SLOPES OF THE BERKSHIRES INTO THE MONADNOCKS. TEMPS WILL FALL BACK
CLOSE TO SEASONAL NORMS. ANOTHER LOW MIGHT MOVE INTO W NY STATE
FRI NIGHT.

&&

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

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

SHORT TERM /TODAY THROUGH FRIDAY NIGHT/...

THROUGH 00Z...LOW VFR/MVFR CIGS AROUND 3000-3500 FT. TREND SHOULD
BE FOR CLOUD DECK TO BECOME SCT TOWARD 00Z..ESPECIALLY NEAR THE
COAST. W/NW GUSTS TO 25-30 KT.

TONIGHT...MODERATE CONFIDENCE. MAINLY VFR...BUT LINGERING MVFR
CIGS ACROSS N CENTRAL-NW MA AND HIGHER TERRAIN THROUGH 03Z OR SO.
DIMINISHING WIND.

FRIDAY...LOW CONFIDENCE DUE TO UNCERTAINTY WITH EXTENT OF ANY MVFR
CIGS. WE HAVE MAINLY VFR IN THE TAFS WITH POCKETS OF MVFR...BUT
IT IS POSSIBLE MVFR CIGS COULD BE MORE EXPANSIVE IF LOW LEVEL
MOISTURE BECOMES TRAPPED BELOW THE INVERSION. LATER FORECASTS
WILL NEED TO REEVALUATE THIS.

FRIDAY NIGHT...MODERATE CONFIDENCE. MAINLY VFR...BUT MVFR CIGS
FROM THE OCEAN EXPANDING WEST ACROSS E MA. LOW PROB FOR SOME OCEAN
EFFECT SNOW SHOWERS OVER CAPE COD AND ACK AFTER MIDNIGHT.

KBOS TERMINAL...MODERATE CONFIDENCE. MAINLY VFR...BUT LOW PROB
FOR MVFR CIGS FRIDAY.

KBDL TERMINAL...MODERATE CONFIDENCE. SHOULD SEE MVFR CIGS SCATTER
OUT THIS EVENING. MVFR CIGS MAY RETURN FRI BUT THIS IS UNCERTAIN.

OUTLOOK...SATURDAY THROUGH TUESDAY...

SATURDAY INTO SUNDAY...HIGH CONFIDENCE. MAINLY VFR ACROSS CENTRAL
AND WESTERN AREAS. E MA INTO RI...AREAS MVFR CIGS/VSBYS IN ANY
RAIN/SNOW SHOWERS...AREAS OF DRIZZLE SAT NIGHT INTO SUN MORNING.

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 FRIDAY NIGHT/...HIGH CONFIDENCE.

TONIGHT...W/NW GUSTS 25-30 KT WILL LINGER OVER THE WATERS INTO
THIS EVENING BEFORE DIMINISHING OVERNIGHT. SCA HEADLINES WILL
CONTINUE TONIGHT.

FRIDAY...NW WINDS WILL BE BELOW SCA THRESHOLDS...BUT HAZARDOUS
SEAS WILL CONTINUE THROUGH THE MORNING OVER THE OUTER EASTERN
WATERS...BEFORE SUBSIDING BELOW SCA. WILL LIKELY NEED TO EXTEND
THE SCA FOR SEAS INTO FRI MORNING.

FRIDAY NIGHT...N/NW WINDS AND SEAS BELOW SCA.

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.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 AM EST FRIDAY FOR ANZ231-232-251.
     SMALL CRAFT ADVISORY UNTIL 11 PM EST THIS EVENING FOR
     ANZ233>235-237.
     SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR ANZ230-
     236.
     SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ250-254>256.

&&

$$
SYNOPSIS...KJC/EVT
NEAR TERM...KJC/EVT
SHORT TERM...KJC
LONG TERM...EVT
AVIATION...KJC/EVT
MARINE...KJC/EVT



000
FXUS61 KBOX 182234
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
534 PM EST THU DEC 18 2014

.SYNOPSIS...
DRY AND SEASONABLE CONDITIONS WILL PREVAIL FRIDAY. AN UPPER LEVEL
DISTURBANCE AND MOIST NORTHEAST FLOW WILL BRING SOME LIGHT
PRECIPITATION SATURDAY INTO SUNDAY. LOW PRESSURE WILL LIKELY PASS
WELL SOUTH OF THE REGION TUESDAY...BUT STILL COULD BRING A PERIOD
OF LIGHT PRECIPITATION. A MUCH STRONGER STORM IS LIKELY TO BRING
HEAVY RAIN AND WIND TO SOUTHERN NEW ENGLAND WEDNESDAY INTO
WEDNESDAY EVENING. DRY BUT VERY WINDY CONDITIONS FOLLOW FOR
CHRISTMAS DAY.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
LOW PRES MOVES NE FROM THE MARITIMES BUT CYCLONIC FLOW WILL
PERSIST ALONG WITH SOME MOISTURE IN THE COLUMN WHICH WILL KEEP A
FEW CLOUDS ACROSS THE REGION ALTHOUGH DRY WEATHER EXPECTED. WHILE
GUSTY WINDS WILL DIMINISH TONIGHT...THERE IS ENOUGH PRESSURE
GRADIENT TO KEEP THE WINDS UP SO TEMPS WILL NOT DROP OFF THAT
QUICKLY. USED A BLEND OF AVAILABLE GUIDANCE WHICH SUGGESTS MIN
TEMPS MOSTLY IN THE 20S...WITH LOWER 30S OVER THE OUTER
CAPE/ISLANDS.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
FRIDAY...
HIGH PRES BUILDS ACROSS THE GRT LAKES WITH NW FLOW ACROSS NEW
ENG. TRICKY CLOUD FORECAST AS NAM INDICATING LOW LEVEL MOISTURE
TRAPPED BELOW INVERSION WITH WIDESPREAD LOW CLOUDS...WHILE GFS AND
ECMWF ARE DRIER IN THE LOW LEVELS. GIVEN LOW LEVEL FLOW IS STILL
NW...WE WILL LEAN MORE OPTIMISTIC THAN NAM WITH A MIX OF CLOUDS
AND SUN EXPECTED. TEMPS WILL LIKELY BE 3-5 DEGREES COLDER THAN
TODAY GIVEN COOLING AT 925 MB...WITH MAX TEMPS RANGING FROM NEAR
30 HIGHER TERRAIN IN NORTHERN AND WESTERN MA TO UPPER 30S IN THE
COASTAL PLAIN.

FRIDAY NIGHT...
MID LEVEL SHORTWAVE MOVES INTO W NEW ENG TOWARD DAYBREAK...BUT
FORCING IS WEAK THROUGH MOST OF THE NIGHT AND MOISTURE IS LIMITED
SO EXPECTING A MAINLY DRY NIGHT. HOWEVER...AS HIGH PRES BUILDS
EASTWARD ACROSS QUEBEC LOW LEVEL WINDS BECOME NE AND MODELS
INDICATE INCREASING LOW MOISTURE BACKING IN ACROSS SE NEW ENG
OVERNIGHT. DELTA T FROM SST TO THE TOP OF THE MIXED LAYER IS
AROUND 13C WHICH IS MARGINAL FOR OCEAN EFFECT AND OCEAN INDUCED
CAPES ARE NOT IMPRESSIVE...BUT LOW LEVEL LAPSE RATES ARE
INCREASING. MODELS DO SHOW SOME LIGHT QPF DEVELOPING SO THERE MAY
BE A FEW SNOW SHOWERS DEVELOPING OVER CAPE COD AND ACK OVERNIGHT
AND WE HAVE SOME LOW CHC POPS.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
HIGHLIGHTS...

* SCT LIGHT SNOW/RAIN SHOWERS SAT INTO SUN...WITH A PERIOD OF
  DRIZZLE/FREEZING DRIZZLE POSSIBLE SAT NIGHT INTO SUN MORNING
* WEAK WAVE OF LOW PRESSURE WILL PASS WELL OFFSHORE TUE BUT COULD
  STILL SEE LIGHT PRECIP
* ANOMALOUSLY STRONG STORM SYSTEM WILL BRING HEAVY RAIN...GUSTY
  WINDS AND COASTAL CONCERNS AROUND CHRISTMAS EVE

OVERVIEW AND MODEL PREFERENCES...
MEDIUM RANGE MODELS CONTINUE IN PRETTY GOOD AGREEMENT ON LARGE
SCALE AND UPPER LEVEL FEATURES THROUGH MOST OF THE FORECAST
PERIOD.

MODELS AND ENSEMBLES CONTINUE TO SIGNAL WEAK SHORT WAVES THAT
TRANSLATE ACROSS THE REGION EARLY IN THIS PERIOD...WITH A RATHER
POTENT BUT FAST MOVING ONE FOR SAT NIGHT/SUN TIMEFRAME WHICH IS
AIDED WITH LOW LEVEL ONSHORE MOISTURE...WITH A SECOND WEAK LOW FOR
LATE MON INTO TUE BRINGING ANOTHER PERIOD OF LIGHT PRECIP.

STILL QUITE A FEW PLACEMENT AND TIMING ISSUES WITH THE EVOLUTION
OF AN ANOMALOUSLY DEEP H5 CUTOFF LOW DEVELOPING ACROSS THE WESTERN
GREAT LAKES AROUND THE MON-TUE TIMEFRAME...THEN ROTATES NE
SOMEWHERE ACROSS S CENTRAL CANADA FOR CHRISTMAS DAY. BIG
IMPLICATIONS WITH THE ASSOCIATED LONG WAVE TROUGH...WITH GUIDANCE
CONTINUING TO INDICATE THE TROUGH BECOMING NEGATIVELY TILTED
ACROSS THE MID ATLC OR SE U.S. LATE IN THIS PERIOD. SECONDARY/
TRIPLE POINT LOW FORMS ON SURFACE FRONT OVER THE EASTERN GULF
AROUND TUESDAY...THEN WORKS UP ACROSS EASTERN PORTIONS OF THE SE
AND MID ATLC STATES. QUESTION IS IF THIS LOW APPROACHES WESTERN
PORTIONS OF NEW ENGLAND WED NIGHT.

STILL SEE THE SIGNALS FOR A FAST MOVING STORM WITH MULTIPLE
IMPACTS POSSIBLE...INCLUDING PERIOD OF HEAVY RAINFALL AND STRONG
WIND GUSTS...FIRST FROM THE SOUTH THEN SHIFTING TO THE WEST. COULD
EVEN SEE SOME COASTAL IMPACTS DURING THE HIGH TIDE CYCLE DURING
WED. TIMING REMAINS AN ISSUE...AS ONE WOULD EXPECT THIS FAR OUT.
MODEL GUIDANCE STILL DOING A RATHER GOOD JOB HANDLING GENERAL
FEATURES OF THIS SYSTEM AT THIS POINT.

USED A BLEND OF THE AVAILABLE GUIDANCE ALONG WITH WPC GUIDANCE.

DETAILS...

SATURDAY INTO SUNDAY...HIGH CONFIDENCE.
HIGH PRES AT THE SURFACE AND ALOFT MOVES ACROSS QUEBEC INTO THE
MARITIMES DURING THIS WEEKEND...THEN TENDS TO SLOW ITS EASTWARD
PROGRESS WITH BLOCKING OVER THE WESTERN ATLC. RATHER POTENT SHORT
WAVE UNDERNEATH THE UPPER SYSTEM MOVES ACROSS THE REGION...AIDED
BY A LOW LEVEL E-NE WIND IN PLACE. A LOT OF LOW LEVEL MOISTURE IN
PLACE AS SEEN ON BUFKIT MODEL SOUNDINGS...SO WILL SEE SOME LIGHT
RAIN/SNOW SHOWERS DEVELOP FROM E-W DURING SATURDAY. EXPECTING
LITTLE IF ANY SNOW ACCUMULATIONS DURING SAT.

HOWEVER...AS TEMPS FALL BACK SAT NIGHT...ALONG WITH THE DEEP LOW
LEVEL MOISTURE FEED...WILL ALSO SEE AREAS OF DRIZZLE DEVELOP. BIG
PROBLEM WILL BE JUST AWAY FROM THE COAST WHERE TEMPS FALL BELOW
FREEZING WHICH MAY MEAN FREEZING DRIZZLE. DOES NOT TAKE MUCH TO
GET GLAZING ESPECIALLY ON UNTREATED SURFACES. WILL NEED TO MONITOR
THIS CLOSELY FOR POSSIBLE WINTER WEATHER HEADLINES ACROSS INTERIOR
E MA INTO RI...POSSIBLY EVEN FURTHER W. WITH THE LIGHT
SNOW...MIGHT SEE UP TO 1/2 INCH ACCUMULATIONS SAT NIGHT INTO SUN
MORNING.

ON SUNDAY...DRIZZLE WILL TAPER OFF DURING THE MORNING...THOUGH
LEFTOVER RAIN/SNOW SHOWERS WILL LINGER THOUGH TEND TO TAPER OFF
DURING THE AFTERNOON.

MONDAY INTO TUESDAY...MODERATE CONFIDENCE.
ANOTHER COASTAL LOW LOOKS TO DEVELOP OFF THE SE U.S. COAST
AND...AS UPPER LEVEL TROUGH BEGINS TO DIG ACROSS THE CENTRAL
U.S...WILL SHIFT TO THE E-NE UNDERNEATH THE UPPER RIDGE. THE
MARITIMES SURFACE HIGH REMAINS PRETTY MUCH IN PLACE...WHICH WILL
HELP SHIFT THE MAIN EFFECTS OF THIS LOW WELL OFFSHORE /SE OF THE
40N/70W BENCHMARK/. HOWEVER...MODELS CONTINUE TO SIGNAL LIGHT
PRECIP REACHING THE COAST MAINLY MON NIGHT INTO TUE. EXPECT MAINLY
MIXED RAIN/SNOW SHOWERS WITH SPOTTY BRIEF PERIODS OF FREEZING
PRECIP AROUND DAYBREAK TUE ACROSS N CT/N RI INTO S CENTRAL MA.
EXPECT HIGH TEMPS ON TUE TO RUN ABOUT 5 DEGS ABOVE SEASONAL NORMS
AS WINDS BEGIN TO SHIFT MORE S- SE...THOUGH SOME TIMING ISSUES IN
PLACE FOR WIND SHIFT AMONGST OP MODELS.

ONCE THE LOW EXITS LATE TUE...WILL ALREADY START TO SEE MOISTURE
FEED UP THE COAST FROM THE DEVELOPING GULF LOW...SO NOT MUCH OF A
BREAK IN THE PRECIP BETWEEN SYSTEMS.

TUESDAY/S LATE MORNING HIGH TIDE WILL RUN UP TO 11.6 FT IN BOSTON
AND...WITH ANY EASTERLY WIND FLOW...THIS MAY CAUSE MINOR COASTAL
FLOODING. WILL MONITOR THIS ASPECT.

WEDNESDAY AND CHRISTMAS DAY...HIGH CONFIDENCE IN SYSTEM...LOW
CONFIDENCE ON DETAILS.

SECONDARY LOW FROM THE PARENT OVER THE NORTHERN GREAT LAKES
DEEPENS AS IT SHIFTS N. MODELS TRY TO PUSH THIS SYSTEM CLOSE TO OR
JUST INTO WESTERN NEW ENGLAND LATE WED/WED NIGHT...THOUGH STILL
TIMING ISSUES IN PLACE. AT THIS POINT...WILL SEE HEAVIEST SLUG OF
PRECIP MOVING ACROSS LATE WED INTO WED EVENING. GOOD TROPICAL
CONNECTION CONTINUES WITH PWATS FROM 1.25 TO 1.4 INCHES...RUNNING
ABOUT +2SD TO +3SD ABOVE NORMAL FOR LATE DECEMBER. GOOD SHOT OF
MILD AIR WORKS IN ON SE- S WINDS. MODELS CONTINUE TO SIGNAL H925
AND H85 FROM 50-65 KT...AND AT LEAST SOME WILL MIX DOWN ESPECIALLY
IF THE LOW PRES PASSES CLOSER /WITH RAPIDLY FALLING PRESSURE/.
HAVE HIGHS ON WED UP TO THE LOWER 50S ACROSS EASTERN AND SOUTHERN
AREAS...BUT COULD BE EVEN HIGHER WITH STRONG ONSHORE WINDS.

CURRENT TIMING SUGGESTS THE DRY SLOT SHOULD WORK INTO THE REGION
LATE WED NIGHT INTO CHRISTMAS MORNING...SO PRECIP SHOULD END. WILL
STILL SEE GUSTY WINDS...THOUGH QUICKLY SHIFTING TO W-SW AND
GUSTING UP TO 25-30 KT...HIGHEST ALONG THE S COAST.

MAY NEED HEADLINES WITH THIS SYSTEM...WITH POSSIBLE URBAN/POOR
DRAINAGE FLOODING IN HEAVY RAINFALL WED/WED NIGHT...STRONG WINDS
BOTH WED AND THU...AND MAYBE EVEN FOR COASTAL CONCERNS. NOTING
ASTRO HIGH TIDES CONTINUE /11.7 AND 11.5 FT AT BOSTON
RESPECTIVELY/... THOUGH TIMING OF WIND SHIFT MAY COME INTO PLAY
FOR CHRISTMAS EVE INTO CHRISTMAS MORNING.

FRIDAY...LOW CONFIDENCE MAINLY FOR TIMING.
ONCE UPPER LOW MOVES INTO SOUTHERN CANADA...EXPECT A RATHER FAST
UPPER W FLOW IN PLACE. MAY SEE LEFTOVER SNOW SHOWERS ACROSS THE E
SLOPES OF THE BERKSHIRES INTO THE MONADNOCKS. TEMPS WILL FALL BACK
CLOSE TO SEASONAL NORMS. ANOTHER LOW MIGHT MOVE INTO W NY STATE
FRI NIGHT.

&&

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

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

SHORT TERM /TODAY THROUGH FRIDAY NIGHT/...

THROUGH 00Z...LOW VFR/MVFR CIGS AROUND 3000-3500 FT. TREND SHOULD
BE FOR CLOUD DECK TO BECOME SCT TOWARD 00Z..ESPECIALLY NEAR THE
COAST. W/NW GUSTS TO 25-30 KT.

TONIGHT...MODERATE CONFIDENCE. MAINLY VFR...BUT LINGERING MVFR
CIGS POSSIBLE IN THE WEST. DIMINISHING WIND.

FRIDAY...LOW CONFIDENCE DUE TO UNCERTAINTY WITH EXTENT OF ANY MVFR
CIGS. WE HAVE MAINLY VFR IN THE TAFS WITH POCKETS OF MVFR...BUT
IT IS POSSIBLE MVFR CIGS COULD BE MORE EXPANSIVE IF LOW LEVEL
MOISTURE BECOMES TRAPPED BELOW THE INVERSION. LATER FORECASTS
WILL NEED TO REEVALUATE THIS.

FRIDAY NIGHT...MODERATE CONFIDENCE. MAINLY VFR...BUT MVFR CIGS
FROM THE OCEAN EXPANDING WEST ACROSS E MA. LOW PROB FOR SOME OCEAN
EFFECT SNOW SHOWERS OVER CAPE COD AND ACK AFTER MIDNIGHT.

KBOS TERMINAL...MODERATE CONFIDENCE. MAINLY VFR...BUT LOW PROB
FOR MVFR CIGS FRIDAY.

KBDL TERMINAL...MODERATE CONFIDENCE. SHOULD SEE MVFR CIGS SCATTER
OUT THIS EVENING. MVFR CIGS MAY RETURN FRI BUT THIS IS UNCERTAIN.

OUTLOOK...SATURDAY THROUGH TUESDAY...

SATURDAY INTO SUNDAY...HIGH CONFIDENCE. MAINLY VFR ACROSS CENTRAL
AND WESTERN AREAS. E MA INTO RI...AREAS MVFR CIGS/VSBYS IN ANY
RAIN/SNOW SHOWERS...AREAS OF DRIZZLE SAT NIGHT INTO SUN MORNING.

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 FRIDAY NIGHT/...HIGH CONFIDENCE.

TONIGHT...W/NW GUSTS 25-30 KT WILL LINGER OVER THE WATERS INTO
THIS EVENING BEFORE DIMINISHING OVERNIGHT. SCA HEADLINES WILL
CONTINUE TONIGHT.

FRIDAY...NW WINDS WILL BE BELOW SCA THRESHOLDS...BUT HAZARDOUS
SEAS WILL CONTINUE THROUGH THE MORNING OVER THE OUTER EASTERN
WATERS...BEFORE SUBSIDING BELOW SCA. WILL LIKELY NEED TO EXTEND
THE SCA FOR SEAS INTO FRI MORNING.

FRIDAY NIGHT...N/NW WINDS AND SEAS BELOW SCA.

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.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 AM EST FRIDAY FOR ANZ231-232-251.
     SMALL CRAFT ADVISORY UNTIL 11 PM EST THIS EVENING FOR
     ANZ233>235-237.
     SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR ANZ230-
     236.
     SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ250-254>256.

&&

$$
SYNOPSIS...KJC/EVT
NEAR TERM...KJC
SHORT TERM...KJC
LONG TERM...EVT
AVIATION...KJC/EVT
MARINE...KJC/EVT




000
FXUS61 KBOX 182234
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
534 PM EST THU DEC 18 2014

.SYNOPSIS...
DRY AND SEASONABLE CONDITIONS WILL PREVAIL FRIDAY. AN UPPER LEVEL
DISTURBANCE AND MOIST NORTHEAST FLOW WILL BRING SOME LIGHT
PRECIPITATION SATURDAY INTO SUNDAY. LOW PRESSURE WILL LIKELY PASS
WELL SOUTH OF THE REGION TUESDAY...BUT STILL COULD BRING A PERIOD
OF LIGHT PRECIPITATION. A MUCH STRONGER STORM IS LIKELY TO BRING
HEAVY RAIN AND WIND TO SOUTHERN NEW ENGLAND WEDNESDAY INTO
WEDNESDAY EVENING. DRY BUT VERY WINDY CONDITIONS FOLLOW FOR
CHRISTMAS DAY.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
LOW PRES MOVES NE FROM THE MARITIMES BUT CYCLONIC FLOW WILL
PERSIST ALONG WITH SOME MOISTURE IN THE COLUMN WHICH WILL KEEP A
FEW CLOUDS ACROSS THE REGION ALTHOUGH DRY WEATHER EXPECTED. WHILE
GUSTY WINDS WILL DIMINISH TONIGHT...THERE IS ENOUGH PRESSURE
GRADIENT TO KEEP THE WINDS UP SO TEMPS WILL NOT DROP OFF THAT
QUICKLY. USED A BLEND OF AVAILABLE GUIDANCE WHICH SUGGESTS MIN
TEMPS MOSTLY IN THE 20S...WITH LOWER 30S OVER THE OUTER
CAPE/ISLANDS.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
FRIDAY...
HIGH PRES BUILDS ACROSS THE GRT LAKES WITH NW FLOW ACROSS NEW
ENG. TRICKY CLOUD FORECAST AS NAM INDICATING LOW LEVEL MOISTURE
TRAPPED BELOW INVERSION WITH WIDESPREAD LOW CLOUDS...WHILE GFS AND
ECMWF ARE DRIER IN THE LOW LEVELS. GIVEN LOW LEVEL FLOW IS STILL
NW...WE WILL LEAN MORE OPTIMISTIC THAN NAM WITH A MIX OF CLOUDS
AND SUN EXPECTED. TEMPS WILL LIKELY BE 3-5 DEGREES COLDER THAN
TODAY GIVEN COOLING AT 925 MB...WITH MAX TEMPS RANGING FROM NEAR
30 HIGHER TERRAIN IN NORTHERN AND WESTERN MA TO UPPER 30S IN THE
COASTAL PLAIN.

FRIDAY NIGHT...
MID LEVEL SHORTWAVE MOVES INTO W NEW ENG TOWARD DAYBREAK...BUT
FORCING IS WEAK THROUGH MOST OF THE NIGHT AND MOISTURE IS LIMITED
SO EXPECTING A MAINLY DRY NIGHT. HOWEVER...AS HIGH PRES BUILDS
EASTWARD ACROSS QUEBEC LOW LEVEL WINDS BECOME NE AND MODELS
INDICATE INCREASING LOW MOISTURE BACKING IN ACROSS SE NEW ENG
OVERNIGHT. DELTA T FROM SST TO THE TOP OF THE MIXED LAYER IS
AROUND 13C WHICH IS MARGINAL FOR OCEAN EFFECT AND OCEAN INDUCED
CAPES ARE NOT IMPRESSIVE...BUT LOW LEVEL LAPSE RATES ARE
INCREASING. MODELS DO SHOW SOME LIGHT QPF DEVELOPING SO THERE MAY
BE A FEW SNOW SHOWERS DEVELOPING OVER CAPE COD AND ACK OVERNIGHT
AND WE HAVE SOME LOW CHC POPS.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
HIGHLIGHTS...

* SCT LIGHT SNOW/RAIN SHOWERS SAT INTO SUN...WITH A PERIOD OF
  DRIZZLE/FREEZING DRIZZLE POSSIBLE SAT NIGHT INTO SUN MORNING
* WEAK WAVE OF LOW PRESSURE WILL PASS WELL OFFSHORE TUE BUT COULD
  STILL SEE LIGHT PRECIP
* ANOMALOUSLY STRONG STORM SYSTEM WILL BRING HEAVY RAIN...GUSTY
  WINDS AND COASTAL CONCERNS AROUND CHRISTMAS EVE

OVERVIEW AND MODEL PREFERENCES...
MEDIUM RANGE MODELS CONTINUE IN PRETTY GOOD AGREEMENT ON LARGE
SCALE AND UPPER LEVEL FEATURES THROUGH MOST OF THE FORECAST
PERIOD.

MODELS AND ENSEMBLES CONTINUE TO SIGNAL WEAK SHORT WAVES THAT
TRANSLATE ACROSS THE REGION EARLY IN THIS PERIOD...WITH A RATHER
POTENT BUT FAST MOVING ONE FOR SAT NIGHT/SUN TIMEFRAME WHICH IS
AIDED WITH LOW LEVEL ONSHORE MOISTURE...WITH A SECOND WEAK LOW FOR
LATE MON INTO TUE BRINGING ANOTHER PERIOD OF LIGHT PRECIP.

STILL QUITE A FEW PLACEMENT AND TIMING ISSUES WITH THE EVOLUTION
OF AN ANOMALOUSLY DEEP H5 CUTOFF LOW DEVELOPING ACROSS THE WESTERN
GREAT LAKES AROUND THE MON-TUE TIMEFRAME...THEN ROTATES NE
SOMEWHERE ACROSS S CENTRAL CANADA FOR CHRISTMAS DAY. BIG
IMPLICATIONS WITH THE ASSOCIATED LONG WAVE TROUGH...WITH GUIDANCE
CONTINUING TO INDICATE THE TROUGH BECOMING NEGATIVELY TILTED
ACROSS THE MID ATLC OR SE U.S. LATE IN THIS PERIOD. SECONDARY/
TRIPLE POINT LOW FORMS ON SURFACE FRONT OVER THE EASTERN GULF
AROUND TUESDAY...THEN WORKS UP ACROSS EASTERN PORTIONS OF THE SE
AND MID ATLC STATES. QUESTION IS IF THIS LOW APPROACHES WESTERN
PORTIONS OF NEW ENGLAND WED NIGHT.

STILL SEE THE SIGNALS FOR A FAST MOVING STORM WITH MULTIPLE
IMPACTS POSSIBLE...INCLUDING PERIOD OF HEAVY RAINFALL AND STRONG
WIND GUSTS...FIRST FROM THE SOUTH THEN SHIFTING TO THE WEST. COULD
EVEN SEE SOME COASTAL IMPACTS DURING THE HIGH TIDE CYCLE DURING
WED. TIMING REMAINS AN ISSUE...AS ONE WOULD EXPECT THIS FAR OUT.
MODEL GUIDANCE STILL DOING A RATHER GOOD JOB HANDLING GENERAL
FEATURES OF THIS SYSTEM AT THIS POINT.

USED A BLEND OF THE AVAILABLE GUIDANCE ALONG WITH WPC GUIDANCE.

DETAILS...

SATURDAY INTO SUNDAY...HIGH CONFIDENCE.
HIGH PRES AT THE SURFACE AND ALOFT MOVES ACROSS QUEBEC INTO THE
MARITIMES DURING THIS WEEKEND...THEN TENDS TO SLOW ITS EASTWARD
PROGRESS WITH BLOCKING OVER THE WESTERN ATLC. RATHER POTENT SHORT
WAVE UNDERNEATH THE UPPER SYSTEM MOVES ACROSS THE REGION...AIDED
BY A LOW LEVEL E-NE WIND IN PLACE. A LOT OF LOW LEVEL MOISTURE IN
PLACE AS SEEN ON BUFKIT MODEL SOUNDINGS...SO WILL SEE SOME LIGHT
RAIN/SNOW SHOWERS DEVELOP FROM E-W DURING SATURDAY. EXPECTING
LITTLE IF ANY SNOW ACCUMULATIONS DURING SAT.

HOWEVER...AS TEMPS FALL BACK SAT NIGHT...ALONG WITH THE DEEP LOW
LEVEL MOISTURE FEED...WILL ALSO SEE AREAS OF DRIZZLE DEVELOP. BIG
PROBLEM WILL BE JUST AWAY FROM THE COAST WHERE TEMPS FALL BELOW
FREEZING WHICH MAY MEAN FREEZING DRIZZLE. DOES NOT TAKE MUCH TO
GET GLAZING ESPECIALLY ON UNTREATED SURFACES. WILL NEED TO MONITOR
THIS CLOSELY FOR POSSIBLE WINTER WEATHER HEADLINES ACROSS INTERIOR
E MA INTO RI...POSSIBLY EVEN FURTHER W. WITH THE LIGHT
SNOW...MIGHT SEE UP TO 1/2 INCH ACCUMULATIONS SAT NIGHT INTO SUN
MORNING.

ON SUNDAY...DRIZZLE WILL TAPER OFF DURING THE MORNING...THOUGH
LEFTOVER RAIN/SNOW SHOWERS WILL LINGER THOUGH TEND TO TAPER OFF
DURING THE AFTERNOON.

MONDAY INTO TUESDAY...MODERATE CONFIDENCE.
ANOTHER COASTAL LOW LOOKS TO DEVELOP OFF THE SE U.S. COAST
AND...AS UPPER LEVEL TROUGH BEGINS TO DIG ACROSS THE CENTRAL
U.S...WILL SHIFT TO THE E-NE UNDERNEATH THE UPPER RIDGE. THE
MARITIMES SURFACE HIGH REMAINS PRETTY MUCH IN PLACE...WHICH WILL
HELP SHIFT THE MAIN EFFECTS OF THIS LOW WELL OFFSHORE /SE OF THE
40N/70W BENCHMARK/. HOWEVER...MODELS CONTINUE TO SIGNAL LIGHT
PRECIP REACHING THE COAST MAINLY MON NIGHT INTO TUE. EXPECT MAINLY
MIXED RAIN/SNOW SHOWERS WITH SPOTTY BRIEF PERIODS OF FREEZING
PRECIP AROUND DAYBREAK TUE ACROSS N CT/N RI INTO S CENTRAL MA.
EXPECT HIGH TEMPS ON TUE TO RUN ABOUT 5 DEGS ABOVE SEASONAL NORMS
AS WINDS BEGIN TO SHIFT MORE S- SE...THOUGH SOME TIMING ISSUES IN
PLACE FOR WIND SHIFT AMONGST OP MODELS.

ONCE THE LOW EXITS LATE TUE...WILL ALREADY START TO SEE MOISTURE
FEED UP THE COAST FROM THE DEVELOPING GULF LOW...SO NOT MUCH OF A
BREAK IN THE PRECIP BETWEEN SYSTEMS.

TUESDAY/S LATE MORNING HIGH TIDE WILL RUN UP TO 11.6 FT IN BOSTON
AND...WITH ANY EASTERLY WIND FLOW...THIS MAY CAUSE MINOR COASTAL
FLOODING. WILL MONITOR THIS ASPECT.

WEDNESDAY AND CHRISTMAS DAY...HIGH CONFIDENCE IN SYSTEM...LOW
CONFIDENCE ON DETAILS.

SECONDARY LOW FROM THE PARENT OVER THE NORTHERN GREAT LAKES
DEEPENS AS IT SHIFTS N. MODELS TRY TO PUSH THIS SYSTEM CLOSE TO OR
JUST INTO WESTERN NEW ENGLAND LATE WED/WED NIGHT...THOUGH STILL
TIMING ISSUES IN PLACE. AT THIS POINT...WILL SEE HEAVIEST SLUG OF
PRECIP MOVING ACROSS LATE WED INTO WED EVENING. GOOD TROPICAL
CONNECTION CONTINUES WITH PWATS FROM 1.25 TO 1.4 INCHES...RUNNING
ABOUT +2SD TO +3SD ABOVE NORMAL FOR LATE DECEMBER. GOOD SHOT OF
MILD AIR WORKS IN ON SE- S WINDS. MODELS CONTINUE TO SIGNAL H925
AND H85 FROM 50-65 KT...AND AT LEAST SOME WILL MIX DOWN ESPECIALLY
IF THE LOW PRES PASSES CLOSER /WITH RAPIDLY FALLING PRESSURE/.
HAVE HIGHS ON WED UP TO THE LOWER 50S ACROSS EASTERN AND SOUTHERN
AREAS...BUT COULD BE EVEN HIGHER WITH STRONG ONSHORE WINDS.

CURRENT TIMING SUGGESTS THE DRY SLOT SHOULD WORK INTO THE REGION
LATE WED NIGHT INTO CHRISTMAS MORNING...SO PRECIP SHOULD END. WILL
STILL SEE GUSTY WINDS...THOUGH QUICKLY SHIFTING TO W-SW AND
GUSTING UP TO 25-30 KT...HIGHEST ALONG THE S COAST.

MAY NEED HEADLINES WITH THIS SYSTEM...WITH POSSIBLE URBAN/POOR
DRAINAGE FLOODING IN HEAVY RAINFALL WED/WED NIGHT...STRONG WINDS
BOTH WED AND THU...AND MAYBE EVEN FOR COASTAL CONCERNS. NOTING
ASTRO HIGH TIDES CONTINUE /11.7 AND 11.5 FT AT BOSTON
RESPECTIVELY/... THOUGH TIMING OF WIND SHIFT MAY COME INTO PLAY
FOR CHRISTMAS EVE INTO CHRISTMAS MORNING.

FRIDAY...LOW CONFIDENCE MAINLY FOR TIMING.
ONCE UPPER LOW MOVES INTO SOUTHERN CANADA...EXPECT A RATHER FAST
UPPER W FLOW IN PLACE. MAY SEE LEFTOVER SNOW SHOWERS ACROSS THE E
SLOPES OF THE BERKSHIRES INTO THE MONADNOCKS. TEMPS WILL FALL BACK
CLOSE TO SEASONAL NORMS. ANOTHER LOW MIGHT MOVE INTO W NY STATE
FRI NIGHT.

&&

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

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

SHORT TERM /TODAY THROUGH FRIDAY NIGHT/...

THROUGH 00Z...LOW VFR/MVFR CIGS AROUND 3000-3500 FT. TREND SHOULD
BE FOR CLOUD DECK TO BECOME SCT TOWARD 00Z..ESPECIALLY NEAR THE
COAST. W/NW GUSTS TO 25-30 KT.

TONIGHT...MODERATE CONFIDENCE. MAINLY VFR...BUT LINGERING MVFR
CIGS POSSIBLE IN THE WEST. DIMINISHING WIND.

FRIDAY...LOW CONFIDENCE DUE TO UNCERTAINTY WITH EXTENT OF ANY MVFR
CIGS. WE HAVE MAINLY VFR IN THE TAFS WITH POCKETS OF MVFR...BUT
IT IS POSSIBLE MVFR CIGS COULD BE MORE EXPANSIVE IF LOW LEVEL
MOISTURE BECOMES TRAPPED BELOW THE INVERSION. LATER FORECASTS
WILL NEED TO REEVALUATE THIS.

FRIDAY NIGHT...MODERATE CONFIDENCE. MAINLY VFR...BUT MVFR CIGS
FROM THE OCEAN EXPANDING WEST ACROSS E MA. LOW PROB FOR SOME OCEAN
EFFECT SNOW SHOWERS OVER CAPE COD AND ACK AFTER MIDNIGHT.

KBOS TERMINAL...MODERATE CONFIDENCE. MAINLY VFR...BUT LOW PROB
FOR MVFR CIGS FRIDAY.

KBDL TERMINAL...MODERATE CONFIDENCE. SHOULD SEE MVFR CIGS SCATTER
OUT THIS EVENING. MVFR CIGS MAY RETURN FRI BUT THIS IS UNCERTAIN.

OUTLOOK...SATURDAY THROUGH TUESDAY...

SATURDAY INTO SUNDAY...HIGH CONFIDENCE. MAINLY VFR ACROSS CENTRAL
AND WESTERN AREAS. E MA INTO RI...AREAS MVFR CIGS/VSBYS IN ANY
RAIN/SNOW SHOWERS...AREAS OF DRIZZLE SAT NIGHT INTO SUN MORNING.

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 FRIDAY NIGHT/...HIGH CONFIDENCE.

TONIGHT...W/NW GUSTS 25-30 KT WILL LINGER OVER THE WATERS INTO
THIS EVENING BEFORE DIMINISHING OVERNIGHT. SCA HEADLINES WILL
CONTINUE TONIGHT.

FRIDAY...NW WINDS WILL BE BELOW SCA THRESHOLDS...BUT HAZARDOUS
SEAS WILL CONTINUE THROUGH THE MORNING OVER THE OUTER EASTERN
WATERS...BEFORE SUBSIDING BELOW SCA. WILL LIKELY NEED TO EXTEND
THE SCA FOR SEAS INTO FRI MORNING.

FRIDAY NIGHT...N/NW WINDS AND SEAS BELOW SCA.

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.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 AM EST FRIDAY FOR ANZ231-232-251.
     SMALL CRAFT ADVISORY UNTIL 11 PM EST THIS EVENING FOR
     ANZ233>235-237.
     SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR ANZ230-
     236.
     SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ250-254>256.

&&

$$
SYNOPSIS...KJC/EVT
NEAR TERM...KJC
SHORT TERM...KJC
LONG TERM...EVT
AVIATION...KJC/EVT
MARINE...KJC/EVT




000
FXUS61 KBOX 182234
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
534 PM EST THU DEC 18 2014

.SYNOPSIS...
DRY AND SEASONABLE CONDITIONS WILL PREVAIL FRIDAY. AN UPPER LEVEL
DISTURBANCE AND MOIST NORTHEAST FLOW WILL BRING SOME LIGHT
PRECIPITATION SATURDAY INTO SUNDAY. LOW PRESSURE WILL LIKELY PASS
WELL SOUTH OF THE REGION TUESDAY...BUT STILL COULD BRING A PERIOD
OF LIGHT PRECIPITATION. A MUCH STRONGER STORM IS LIKELY TO BRING
HEAVY RAIN AND WIND TO SOUTHERN NEW ENGLAND WEDNESDAY INTO
WEDNESDAY EVENING. DRY BUT VERY WINDY CONDITIONS FOLLOW FOR
CHRISTMAS DAY.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
LOW PRES MOVES NE FROM THE MARITIMES BUT CYCLONIC FLOW WILL
PERSIST ALONG WITH SOME MOISTURE IN THE COLUMN WHICH WILL KEEP A
FEW CLOUDS ACROSS THE REGION ALTHOUGH DRY WEATHER EXPECTED. WHILE
GUSTY WINDS WILL DIMINISH TONIGHT...THERE IS ENOUGH PRESSURE
GRADIENT TO KEEP THE WINDS UP SO TEMPS WILL NOT DROP OFF THAT
QUICKLY. USED A BLEND OF AVAILABLE GUIDANCE WHICH SUGGESTS MIN
TEMPS MOSTLY IN THE 20S...WITH LOWER 30S OVER THE OUTER
CAPE/ISLANDS.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
FRIDAY...
HIGH PRES BUILDS ACROSS THE GRT LAKES WITH NW FLOW ACROSS NEW
ENG. TRICKY CLOUD FORECAST AS NAM INDICATING LOW LEVEL MOISTURE
TRAPPED BELOW INVERSION WITH WIDESPREAD LOW CLOUDS...WHILE GFS AND
ECMWF ARE DRIER IN THE LOW LEVELS. GIVEN LOW LEVEL FLOW IS STILL
NW...WE WILL LEAN MORE OPTIMISTIC THAN NAM WITH A MIX OF CLOUDS
AND SUN EXPECTED. TEMPS WILL LIKELY BE 3-5 DEGREES COLDER THAN
TODAY GIVEN COOLING AT 925 MB...WITH MAX TEMPS RANGING FROM NEAR
30 HIGHER TERRAIN IN NORTHERN AND WESTERN MA TO UPPER 30S IN THE
COASTAL PLAIN.

FRIDAY NIGHT...
MID LEVEL SHORTWAVE MOVES INTO W NEW ENG TOWARD DAYBREAK...BUT
FORCING IS WEAK THROUGH MOST OF THE NIGHT AND MOISTURE IS LIMITED
SO EXPECTING A MAINLY DRY NIGHT. HOWEVER...AS HIGH PRES BUILDS
EASTWARD ACROSS QUEBEC LOW LEVEL WINDS BECOME NE AND MODELS
INDICATE INCREASING LOW MOISTURE BACKING IN ACROSS SE NEW ENG
OVERNIGHT. DELTA T FROM SST TO THE TOP OF THE MIXED LAYER IS
AROUND 13C WHICH IS MARGINAL FOR OCEAN EFFECT AND OCEAN INDUCED
CAPES ARE NOT IMPRESSIVE...BUT LOW LEVEL LAPSE RATES ARE
INCREASING. MODELS DO SHOW SOME LIGHT QPF DEVELOPING SO THERE MAY
BE A FEW SNOW SHOWERS DEVELOPING OVER CAPE COD AND ACK OVERNIGHT
AND WE HAVE SOME LOW CHC POPS.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
HIGHLIGHTS...

* SCT LIGHT SNOW/RAIN SHOWERS SAT INTO SUN...WITH A PERIOD OF
  DRIZZLE/FREEZING DRIZZLE POSSIBLE SAT NIGHT INTO SUN MORNING
* WEAK WAVE OF LOW PRESSURE WILL PASS WELL OFFSHORE TUE BUT COULD
  STILL SEE LIGHT PRECIP
* ANOMALOUSLY STRONG STORM SYSTEM WILL BRING HEAVY RAIN...GUSTY
  WINDS AND COASTAL CONCERNS AROUND CHRISTMAS EVE

OVERVIEW AND MODEL PREFERENCES...
MEDIUM RANGE MODELS CONTINUE IN PRETTY GOOD AGREEMENT ON LARGE
SCALE AND UPPER LEVEL FEATURES THROUGH MOST OF THE FORECAST
PERIOD.

MODELS AND ENSEMBLES CONTINUE TO SIGNAL WEAK SHORT WAVES THAT
TRANSLATE ACROSS THE REGION EARLY IN THIS PERIOD...WITH A RATHER
POTENT BUT FAST MOVING ONE FOR SAT NIGHT/SUN TIMEFRAME WHICH IS
AIDED WITH LOW LEVEL ONSHORE MOISTURE...WITH A SECOND WEAK LOW FOR
LATE MON INTO TUE BRINGING ANOTHER PERIOD OF LIGHT PRECIP.

STILL QUITE A FEW PLACEMENT AND TIMING ISSUES WITH THE EVOLUTION
OF AN ANOMALOUSLY DEEP H5 CUTOFF LOW DEVELOPING ACROSS THE WESTERN
GREAT LAKES AROUND THE MON-TUE TIMEFRAME...THEN ROTATES NE
SOMEWHERE ACROSS S CENTRAL CANADA FOR CHRISTMAS DAY. BIG
IMPLICATIONS WITH THE ASSOCIATED LONG WAVE TROUGH...WITH GUIDANCE
CONTINUING TO INDICATE THE TROUGH BECOMING NEGATIVELY TILTED
ACROSS THE MID ATLC OR SE U.S. LATE IN THIS PERIOD. SECONDARY/
TRIPLE POINT LOW FORMS ON SURFACE FRONT OVER THE EASTERN GULF
AROUND TUESDAY...THEN WORKS UP ACROSS EASTERN PORTIONS OF THE SE
AND MID ATLC STATES. QUESTION IS IF THIS LOW APPROACHES WESTERN
PORTIONS OF NEW ENGLAND WED NIGHT.

STILL SEE THE SIGNALS FOR A FAST MOVING STORM WITH MULTIPLE
IMPACTS POSSIBLE...INCLUDING PERIOD OF HEAVY RAINFALL AND STRONG
WIND GUSTS...FIRST FROM THE SOUTH THEN SHIFTING TO THE WEST. COULD
EVEN SEE SOME COASTAL IMPACTS DURING THE HIGH TIDE CYCLE DURING
WED. TIMING REMAINS AN ISSUE...AS ONE WOULD EXPECT THIS FAR OUT.
MODEL GUIDANCE STILL DOING A RATHER GOOD JOB HANDLING GENERAL
FEATURES OF THIS SYSTEM AT THIS POINT.

USED A BLEND OF THE AVAILABLE GUIDANCE ALONG WITH WPC GUIDANCE.

DETAILS...

SATURDAY INTO SUNDAY...HIGH CONFIDENCE.
HIGH PRES AT THE SURFACE AND ALOFT MOVES ACROSS QUEBEC INTO THE
MARITIMES DURING THIS WEEKEND...THEN TENDS TO SLOW ITS EASTWARD
PROGRESS WITH BLOCKING OVER THE WESTERN ATLC. RATHER POTENT SHORT
WAVE UNDERNEATH THE UPPER SYSTEM MOVES ACROSS THE REGION...AIDED
BY A LOW LEVEL E-NE WIND IN PLACE. A LOT OF LOW LEVEL MOISTURE IN
PLACE AS SEEN ON BUFKIT MODEL SOUNDINGS...SO WILL SEE SOME LIGHT
RAIN/SNOW SHOWERS DEVELOP FROM E-W DURING SATURDAY. EXPECTING
LITTLE IF ANY SNOW ACCUMULATIONS DURING SAT.

HOWEVER...AS TEMPS FALL BACK SAT NIGHT...ALONG WITH THE DEEP LOW
LEVEL MOISTURE FEED...WILL ALSO SEE AREAS OF DRIZZLE DEVELOP. BIG
PROBLEM WILL BE JUST AWAY FROM THE COAST WHERE TEMPS FALL BELOW
FREEZING WHICH MAY MEAN FREEZING DRIZZLE. DOES NOT TAKE MUCH TO
GET GLAZING ESPECIALLY ON UNTREATED SURFACES. WILL NEED TO MONITOR
THIS CLOSELY FOR POSSIBLE WINTER WEATHER HEADLINES ACROSS INTERIOR
E MA INTO RI...POSSIBLY EVEN FURTHER W. WITH THE LIGHT
SNOW...MIGHT SEE UP TO 1/2 INCH ACCUMULATIONS SAT NIGHT INTO SUN
MORNING.

ON SUNDAY...DRIZZLE WILL TAPER OFF DURING THE MORNING...THOUGH
LEFTOVER RAIN/SNOW SHOWERS WILL LINGER THOUGH TEND TO TAPER OFF
DURING THE AFTERNOON.

MONDAY INTO TUESDAY...MODERATE CONFIDENCE.
ANOTHER COASTAL LOW LOOKS TO DEVELOP OFF THE SE U.S. COAST
AND...AS UPPER LEVEL TROUGH BEGINS TO DIG ACROSS THE CENTRAL
U.S...WILL SHIFT TO THE E-NE UNDERNEATH THE UPPER RIDGE. THE
MARITIMES SURFACE HIGH REMAINS PRETTY MUCH IN PLACE...WHICH WILL
HELP SHIFT THE MAIN EFFECTS OF THIS LOW WELL OFFSHORE /SE OF THE
40N/70W BENCHMARK/. HOWEVER...MODELS CONTINUE TO SIGNAL LIGHT
PRECIP REACHING THE COAST MAINLY MON NIGHT INTO TUE. EXPECT MAINLY
MIXED RAIN/SNOW SHOWERS WITH SPOTTY BRIEF PERIODS OF FREEZING
PRECIP AROUND DAYBREAK TUE ACROSS N CT/N RI INTO S CENTRAL MA.
EXPECT HIGH TEMPS ON TUE TO RUN ABOUT 5 DEGS ABOVE SEASONAL NORMS
AS WINDS BEGIN TO SHIFT MORE S- SE...THOUGH SOME TIMING ISSUES IN
PLACE FOR WIND SHIFT AMONGST OP MODELS.

ONCE THE LOW EXITS LATE TUE...WILL ALREADY START TO SEE MOISTURE
FEED UP THE COAST FROM THE DEVELOPING GULF LOW...SO NOT MUCH OF A
BREAK IN THE PRECIP BETWEEN SYSTEMS.

TUESDAY/S LATE MORNING HIGH TIDE WILL RUN UP TO 11.6 FT IN BOSTON
AND...WITH ANY EASTERLY WIND FLOW...THIS MAY CAUSE MINOR COASTAL
FLOODING. WILL MONITOR THIS ASPECT.

WEDNESDAY AND CHRISTMAS DAY...HIGH CONFIDENCE IN SYSTEM...LOW
CONFIDENCE ON DETAILS.

SECONDARY LOW FROM THE PARENT OVER THE NORTHERN GREAT LAKES
DEEPENS AS IT SHIFTS N. MODELS TRY TO PUSH THIS SYSTEM CLOSE TO OR
JUST INTO WESTERN NEW ENGLAND LATE WED/WED NIGHT...THOUGH STILL
TIMING ISSUES IN PLACE. AT THIS POINT...WILL SEE HEAVIEST SLUG OF
PRECIP MOVING ACROSS LATE WED INTO WED EVENING. GOOD TROPICAL
CONNECTION CONTINUES WITH PWATS FROM 1.25 TO 1.4 INCHES...RUNNING
ABOUT +2SD TO +3SD ABOVE NORMAL FOR LATE DECEMBER. GOOD SHOT OF
MILD AIR WORKS IN ON SE- S WINDS. MODELS CONTINUE TO SIGNAL H925
AND H85 FROM 50-65 KT...AND AT LEAST SOME WILL MIX DOWN ESPECIALLY
IF THE LOW PRES PASSES CLOSER /WITH RAPIDLY FALLING PRESSURE/.
HAVE HIGHS ON WED UP TO THE LOWER 50S ACROSS EASTERN AND SOUTHERN
AREAS...BUT COULD BE EVEN HIGHER WITH STRONG ONSHORE WINDS.

CURRENT TIMING SUGGESTS THE DRY SLOT SHOULD WORK INTO THE REGION
LATE WED NIGHT INTO CHRISTMAS MORNING...SO PRECIP SHOULD END. WILL
STILL SEE GUSTY WINDS...THOUGH QUICKLY SHIFTING TO W-SW AND
GUSTING UP TO 25-30 KT...HIGHEST ALONG THE S COAST.

MAY NEED HEADLINES WITH THIS SYSTEM...WITH POSSIBLE URBAN/POOR
DRAINAGE FLOODING IN HEAVY RAINFALL WED/WED NIGHT...STRONG WINDS
BOTH WED AND THU...AND MAYBE EVEN FOR COASTAL CONCERNS. NOTING
ASTRO HIGH TIDES CONTINUE /11.7 AND 11.5 FT AT BOSTON
RESPECTIVELY/... THOUGH TIMING OF WIND SHIFT MAY COME INTO PLAY
FOR CHRISTMAS EVE INTO CHRISTMAS MORNING.

FRIDAY...LOW CONFIDENCE MAINLY FOR TIMING.
ONCE UPPER LOW MOVES INTO SOUTHERN CANADA...EXPECT A RATHER FAST
UPPER W FLOW IN PLACE. MAY SEE LEFTOVER SNOW SHOWERS ACROSS THE E
SLOPES OF THE BERKSHIRES INTO THE MONADNOCKS. TEMPS WILL FALL BACK
CLOSE TO SEASONAL NORMS. ANOTHER LOW MIGHT MOVE INTO W NY STATE
FRI NIGHT.

&&

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

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

SHORT TERM /TODAY THROUGH FRIDAY NIGHT/...

THROUGH 00Z...LOW VFR/MVFR CIGS AROUND 3000-3500 FT. TREND SHOULD
BE FOR CLOUD DECK TO BECOME SCT TOWARD 00Z..ESPECIALLY NEAR THE
COAST. W/NW GUSTS TO 25-30 KT.

TONIGHT...MODERATE CONFIDENCE. MAINLY VFR...BUT LINGERING MVFR
CIGS POSSIBLE IN THE WEST. DIMINISHING WIND.

FRIDAY...LOW CONFIDENCE DUE TO UNCERTAINTY WITH EXTENT OF ANY MVFR
CIGS. WE HAVE MAINLY VFR IN THE TAFS WITH POCKETS OF MVFR...BUT
IT IS POSSIBLE MVFR CIGS COULD BE MORE EXPANSIVE IF LOW LEVEL
MOISTURE BECOMES TRAPPED BELOW THE INVERSION. LATER FORECASTS
WILL NEED TO REEVALUATE THIS.

FRIDAY NIGHT...MODERATE CONFIDENCE. MAINLY VFR...BUT MVFR CIGS
FROM THE OCEAN EXPANDING WEST ACROSS E MA. LOW PROB FOR SOME OCEAN
EFFECT SNOW SHOWERS OVER CAPE COD AND ACK AFTER MIDNIGHT.

KBOS TERMINAL...MODERATE CONFIDENCE. MAINLY VFR...BUT LOW PROB
FOR MVFR CIGS FRIDAY.

KBDL TERMINAL...MODERATE CONFIDENCE. SHOULD SEE MVFR CIGS SCATTER
OUT THIS EVENING. MVFR CIGS MAY RETURN FRI BUT THIS IS UNCERTAIN.

OUTLOOK...SATURDAY THROUGH TUESDAY...

SATURDAY INTO SUNDAY...HIGH CONFIDENCE. MAINLY VFR ACROSS CENTRAL
AND WESTERN AREAS. E MA INTO RI...AREAS MVFR CIGS/VSBYS IN ANY
RAIN/SNOW SHOWERS...AREAS OF DRIZZLE SAT NIGHT INTO SUN MORNING.

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 FRIDAY NIGHT/...HIGH CONFIDENCE.

TONIGHT...W/NW GUSTS 25-30 KT WILL LINGER OVER THE WATERS INTO
THIS EVENING BEFORE DIMINISHING OVERNIGHT. SCA HEADLINES WILL
CONTINUE TONIGHT.

FRIDAY...NW WINDS WILL BE BELOW SCA THRESHOLDS...BUT HAZARDOUS
SEAS WILL CONTINUE THROUGH THE MORNING OVER THE OUTER EASTERN
WATERS...BEFORE SUBSIDING BELOW SCA. WILL LIKELY NEED TO EXTEND
THE SCA FOR SEAS INTO FRI MORNING.

FRIDAY NIGHT...N/NW WINDS AND SEAS BELOW SCA.

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.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 AM EST FRIDAY FOR ANZ231-232-251.
     SMALL CRAFT ADVISORY UNTIL 11 PM EST THIS EVENING FOR
     ANZ233>235-237.
     SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR ANZ230-
     236.
     SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ250-254>256.

&&

$$
SYNOPSIS...KJC/EVT
NEAR TERM...KJC
SHORT TERM...KJC
LONG TERM...EVT
AVIATION...KJC/EVT
MARINE...KJC/EVT




000
FXUS61 KBOX 182234
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
534 PM EST THU DEC 18 2014

.SYNOPSIS...
DRY AND SEASONABLE CONDITIONS WILL PREVAIL FRIDAY. AN UPPER LEVEL
DISTURBANCE AND MOIST NORTHEAST FLOW WILL BRING SOME LIGHT
PRECIPITATION SATURDAY INTO SUNDAY. LOW PRESSURE WILL LIKELY PASS
WELL SOUTH OF THE REGION TUESDAY...BUT STILL COULD BRING A PERIOD
OF LIGHT PRECIPITATION. A MUCH STRONGER STORM IS LIKELY TO BRING
HEAVY RAIN AND WIND TO SOUTHERN NEW ENGLAND WEDNESDAY INTO
WEDNESDAY EVENING. DRY BUT VERY WINDY CONDITIONS FOLLOW FOR
CHRISTMAS DAY.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
LOW PRES MOVES NE FROM THE MARITIMES BUT CYCLONIC FLOW WILL
PERSIST ALONG WITH SOME MOISTURE IN THE COLUMN WHICH WILL KEEP A
FEW CLOUDS ACROSS THE REGION ALTHOUGH DRY WEATHER EXPECTED. WHILE
GUSTY WINDS WILL DIMINISH TONIGHT...THERE IS ENOUGH PRESSURE
GRADIENT TO KEEP THE WINDS UP SO TEMPS WILL NOT DROP OFF THAT
QUICKLY. USED A BLEND OF AVAILABLE GUIDANCE WHICH SUGGESTS MIN
TEMPS MOSTLY IN THE 20S...WITH LOWER 30S OVER THE OUTER
CAPE/ISLANDS.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
FRIDAY...
HIGH PRES BUILDS ACROSS THE GRT LAKES WITH NW FLOW ACROSS NEW
ENG. TRICKY CLOUD FORECAST AS NAM INDICATING LOW LEVEL MOISTURE
TRAPPED BELOW INVERSION WITH WIDESPREAD LOW CLOUDS...WHILE GFS AND
ECMWF ARE DRIER IN THE LOW LEVELS. GIVEN LOW LEVEL FLOW IS STILL
NW...WE WILL LEAN MORE OPTIMISTIC THAN NAM WITH A MIX OF CLOUDS
AND SUN EXPECTED. TEMPS WILL LIKELY BE 3-5 DEGREES COLDER THAN
TODAY GIVEN COOLING AT 925 MB...WITH MAX TEMPS RANGING FROM NEAR
30 HIGHER TERRAIN IN NORTHERN AND WESTERN MA TO UPPER 30S IN THE
COASTAL PLAIN.

FRIDAY NIGHT...
MID LEVEL SHORTWAVE MOVES INTO W NEW ENG TOWARD DAYBREAK...BUT
FORCING IS WEAK THROUGH MOST OF THE NIGHT AND MOISTURE IS LIMITED
SO EXPECTING A MAINLY DRY NIGHT. HOWEVER...AS HIGH PRES BUILDS
EASTWARD ACROSS QUEBEC LOW LEVEL WINDS BECOME NE AND MODELS
INDICATE INCREASING LOW MOISTURE BACKING IN ACROSS SE NEW ENG
OVERNIGHT. DELTA T FROM SST TO THE TOP OF THE MIXED LAYER IS
AROUND 13C WHICH IS MARGINAL FOR OCEAN EFFECT AND OCEAN INDUCED
CAPES ARE NOT IMPRESSIVE...BUT LOW LEVEL LAPSE RATES ARE
INCREASING. MODELS DO SHOW SOME LIGHT QPF DEVELOPING SO THERE MAY
BE A FEW SNOW SHOWERS DEVELOPING OVER CAPE COD AND ACK OVERNIGHT
AND WE HAVE SOME LOW CHC POPS.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
HIGHLIGHTS...

* SCT LIGHT SNOW/RAIN SHOWERS SAT INTO SUN...WITH A PERIOD OF
  DRIZZLE/FREEZING DRIZZLE POSSIBLE SAT NIGHT INTO SUN MORNING
* WEAK WAVE OF LOW PRESSURE WILL PASS WELL OFFSHORE TUE BUT COULD
  STILL SEE LIGHT PRECIP
* ANOMALOUSLY STRONG STORM SYSTEM WILL BRING HEAVY RAIN...GUSTY
  WINDS AND COASTAL CONCERNS AROUND CHRISTMAS EVE

OVERVIEW AND MODEL PREFERENCES...
MEDIUM RANGE MODELS CONTINUE IN PRETTY GOOD AGREEMENT ON LARGE
SCALE AND UPPER LEVEL FEATURES THROUGH MOST OF THE FORECAST
PERIOD.

MODELS AND ENSEMBLES CONTINUE TO SIGNAL WEAK SHORT WAVES THAT
TRANSLATE ACROSS THE REGION EARLY IN THIS PERIOD...WITH A RATHER
POTENT BUT FAST MOVING ONE FOR SAT NIGHT/SUN TIMEFRAME WHICH IS
AIDED WITH LOW LEVEL ONSHORE MOISTURE...WITH A SECOND WEAK LOW FOR
LATE MON INTO TUE BRINGING ANOTHER PERIOD OF LIGHT PRECIP.

STILL QUITE A FEW PLACEMENT AND TIMING ISSUES WITH THE EVOLUTION
OF AN ANOMALOUSLY DEEP H5 CUTOFF LOW DEVELOPING ACROSS THE WESTERN
GREAT LAKES AROUND THE MON-TUE TIMEFRAME...THEN ROTATES NE
SOMEWHERE ACROSS S CENTRAL CANADA FOR CHRISTMAS DAY. BIG
IMPLICATIONS WITH THE ASSOCIATED LONG WAVE TROUGH...WITH GUIDANCE
CONTINUING TO INDICATE THE TROUGH BECOMING NEGATIVELY TILTED
ACROSS THE MID ATLC OR SE U.S. LATE IN THIS PERIOD. SECONDARY/
TRIPLE POINT LOW FORMS ON SURFACE FRONT OVER THE EASTERN GULF
AROUND TUESDAY...THEN WORKS UP ACROSS EASTERN PORTIONS OF THE SE
AND MID ATLC STATES. QUESTION IS IF THIS LOW APPROACHES WESTERN
PORTIONS OF NEW ENGLAND WED NIGHT.

STILL SEE THE SIGNALS FOR A FAST MOVING STORM WITH MULTIPLE
IMPACTS POSSIBLE...INCLUDING PERIOD OF HEAVY RAINFALL AND STRONG
WIND GUSTS...FIRST FROM THE SOUTH THEN SHIFTING TO THE WEST. COULD
EVEN SEE SOME COASTAL IMPACTS DURING THE HIGH TIDE CYCLE DURING
WED. TIMING REMAINS AN ISSUE...AS ONE WOULD EXPECT THIS FAR OUT.
MODEL GUIDANCE STILL DOING A RATHER GOOD JOB HANDLING GENERAL
FEATURES OF THIS SYSTEM AT THIS POINT.

USED A BLEND OF THE AVAILABLE GUIDANCE ALONG WITH WPC GUIDANCE.

DETAILS...

SATURDAY INTO SUNDAY...HIGH CONFIDENCE.
HIGH PRES AT THE SURFACE AND ALOFT MOVES ACROSS QUEBEC INTO THE
MARITIMES DURING THIS WEEKEND...THEN TENDS TO SLOW ITS EASTWARD
PROGRESS WITH BLOCKING OVER THE WESTERN ATLC. RATHER POTENT SHORT
WAVE UNDERNEATH THE UPPER SYSTEM MOVES ACROSS THE REGION...AIDED
BY A LOW LEVEL E-NE WIND IN PLACE. A LOT OF LOW LEVEL MOISTURE IN
PLACE AS SEEN ON BUFKIT MODEL SOUNDINGS...SO WILL SEE SOME LIGHT
RAIN/SNOW SHOWERS DEVELOP FROM E-W DURING SATURDAY. EXPECTING
LITTLE IF ANY SNOW ACCUMULATIONS DURING SAT.

HOWEVER...AS TEMPS FALL BACK SAT NIGHT...ALONG WITH THE DEEP LOW
LEVEL MOISTURE FEED...WILL ALSO SEE AREAS OF DRIZZLE DEVELOP. BIG
PROBLEM WILL BE JUST AWAY FROM THE COAST WHERE TEMPS FALL BELOW
FREEZING WHICH MAY MEAN FREEZING DRIZZLE. DOES NOT TAKE MUCH TO
GET GLAZING ESPECIALLY ON UNTREATED SURFACES. WILL NEED TO MONITOR
THIS CLOSELY FOR POSSIBLE WINTER WEATHER HEADLINES ACROSS INTERIOR
E MA INTO RI...POSSIBLY EVEN FURTHER W. WITH THE LIGHT
SNOW...MIGHT SEE UP TO 1/2 INCH ACCUMULATIONS SAT NIGHT INTO SUN
MORNING.

ON SUNDAY...DRIZZLE WILL TAPER OFF DURING THE MORNING...THOUGH
LEFTOVER RAIN/SNOW SHOWERS WILL LINGER THOUGH TEND TO TAPER OFF
DURING THE AFTERNOON.

MONDAY INTO TUESDAY...MODERATE CONFIDENCE.
ANOTHER COASTAL LOW LOOKS TO DEVELOP OFF THE SE U.S. COAST
AND...AS UPPER LEVEL TROUGH BEGINS TO DIG ACROSS THE CENTRAL
U.S...WILL SHIFT TO THE E-NE UNDERNEATH THE UPPER RIDGE. THE
MARITIMES SURFACE HIGH REMAINS PRETTY MUCH IN PLACE...WHICH WILL
HELP SHIFT THE MAIN EFFECTS OF THIS LOW WELL OFFSHORE /SE OF THE
40N/70W BENCHMARK/. HOWEVER...MODELS CONTINUE TO SIGNAL LIGHT
PRECIP REACHING THE COAST MAINLY MON NIGHT INTO TUE. EXPECT MAINLY
MIXED RAIN/SNOW SHOWERS WITH SPOTTY BRIEF PERIODS OF FREEZING
PRECIP AROUND DAYBREAK TUE ACROSS N CT/N RI INTO S CENTRAL MA.
EXPECT HIGH TEMPS ON TUE TO RUN ABOUT 5 DEGS ABOVE SEASONAL NORMS
AS WINDS BEGIN TO SHIFT MORE S- SE...THOUGH SOME TIMING ISSUES IN
PLACE FOR WIND SHIFT AMONGST OP MODELS.

ONCE THE LOW EXITS LATE TUE...WILL ALREADY START TO SEE MOISTURE
FEED UP THE COAST FROM THE DEVELOPING GULF LOW...SO NOT MUCH OF A
BREAK IN THE PRECIP BETWEEN SYSTEMS.

TUESDAY/S LATE MORNING HIGH TIDE WILL RUN UP TO 11.6 FT IN BOSTON
AND...WITH ANY EASTERLY WIND FLOW...THIS MAY CAUSE MINOR COASTAL
FLOODING. WILL MONITOR THIS ASPECT.

WEDNESDAY AND CHRISTMAS DAY...HIGH CONFIDENCE IN SYSTEM...LOW
CONFIDENCE ON DETAILS.

SECONDARY LOW FROM THE PARENT OVER THE NORTHERN GREAT LAKES
DEEPENS AS IT SHIFTS N. MODELS TRY TO PUSH THIS SYSTEM CLOSE TO OR
JUST INTO WESTERN NEW ENGLAND LATE WED/WED NIGHT...THOUGH STILL
TIMING ISSUES IN PLACE. AT THIS POINT...WILL SEE HEAVIEST SLUG OF
PRECIP MOVING ACROSS LATE WED INTO WED EVENING. GOOD TROPICAL
CONNECTION CONTINUES WITH PWATS FROM 1.25 TO 1.4 INCHES...RUNNING
ABOUT +2SD TO +3SD ABOVE NORMAL FOR LATE DECEMBER. GOOD SHOT OF
MILD AIR WORKS IN ON SE- S WINDS. MODELS CONTINUE TO SIGNAL H925
AND H85 FROM 50-65 KT...AND AT LEAST SOME WILL MIX DOWN ESPECIALLY
IF THE LOW PRES PASSES CLOSER /WITH RAPIDLY FALLING PRESSURE/.
HAVE HIGHS ON WED UP TO THE LOWER 50S ACROSS EASTERN AND SOUTHERN
AREAS...BUT COULD BE EVEN HIGHER WITH STRONG ONSHORE WINDS.

CURRENT TIMING SUGGESTS THE DRY SLOT SHOULD WORK INTO THE REGION
LATE WED NIGHT INTO CHRISTMAS MORNING...SO PRECIP SHOULD END. WILL
STILL SEE GUSTY WINDS...THOUGH QUICKLY SHIFTING TO W-SW AND
GUSTING UP TO 25-30 KT...HIGHEST ALONG THE S COAST.

MAY NEED HEADLINES WITH THIS SYSTEM...WITH POSSIBLE URBAN/POOR
DRAINAGE FLOODING IN HEAVY RAINFALL WED/WED NIGHT...STRONG WINDS
BOTH WED AND THU...AND MAYBE EVEN FOR COASTAL CONCERNS. NOTING
ASTRO HIGH TIDES CONTINUE /11.7 AND 11.5 FT AT BOSTON
RESPECTIVELY/... THOUGH TIMING OF WIND SHIFT MAY COME INTO PLAY
FOR CHRISTMAS EVE INTO CHRISTMAS MORNING.

FRIDAY...LOW CONFIDENCE MAINLY FOR TIMING.
ONCE UPPER LOW MOVES INTO SOUTHERN CANADA...EXPECT A RATHER FAST
UPPER W FLOW IN PLACE. MAY SEE LEFTOVER SNOW SHOWERS ACROSS THE E
SLOPES OF THE BERKSHIRES INTO THE MONADNOCKS. TEMPS WILL FALL BACK
CLOSE TO SEASONAL NORMS. ANOTHER LOW MIGHT MOVE INTO W NY STATE
FRI NIGHT.

&&

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

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

SHORT TERM /TODAY THROUGH FRIDAY NIGHT/...

THROUGH 00Z...LOW VFR/MVFR CIGS AROUND 3000-3500 FT. TREND SHOULD
BE FOR CLOUD DECK TO BECOME SCT TOWARD 00Z..ESPECIALLY NEAR THE
COAST. W/NW GUSTS TO 25-30 KT.

TONIGHT...MODERATE CONFIDENCE. MAINLY VFR...BUT LINGERING MVFR
CIGS POSSIBLE IN THE WEST. DIMINISHING WIND.

FRIDAY...LOW CONFIDENCE DUE TO UNCERTAINTY WITH EXTENT OF ANY MVFR
CIGS. WE HAVE MAINLY VFR IN THE TAFS WITH POCKETS OF MVFR...BUT
IT IS POSSIBLE MVFR CIGS COULD BE MORE EXPANSIVE IF LOW LEVEL
MOISTURE BECOMES TRAPPED BELOW THE INVERSION. LATER FORECASTS
WILL NEED TO REEVALUATE THIS.

FRIDAY NIGHT...MODERATE CONFIDENCE. MAINLY VFR...BUT MVFR CIGS
FROM THE OCEAN EXPANDING WEST ACROSS E MA. LOW PROB FOR SOME OCEAN
EFFECT SNOW SHOWERS OVER CAPE COD AND ACK AFTER MIDNIGHT.

KBOS TERMINAL...MODERATE CONFIDENCE. MAINLY VFR...BUT LOW PROB
FOR MVFR CIGS FRIDAY.

KBDL TERMINAL...MODERATE CONFIDENCE. SHOULD SEE MVFR CIGS SCATTER
OUT THIS EVENING. MVFR CIGS MAY RETURN FRI BUT THIS IS UNCERTAIN.

OUTLOOK...SATURDAY THROUGH TUESDAY...

SATURDAY INTO SUNDAY...HIGH CONFIDENCE. MAINLY VFR ACROSS CENTRAL
AND WESTERN AREAS. E MA INTO RI...AREAS MVFR CIGS/VSBYS IN ANY
RAIN/SNOW SHOWERS...AREAS OF DRIZZLE SAT NIGHT INTO SUN MORNING.

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 FRIDAY NIGHT/...HIGH CONFIDENCE.

TONIGHT...W/NW GUSTS 25-30 KT WILL LINGER OVER THE WATERS INTO
THIS EVENING BEFORE DIMINISHING OVERNIGHT. SCA HEADLINES WILL
CONTINUE TONIGHT.

FRIDAY...NW WINDS WILL BE BELOW SCA THRESHOLDS...BUT HAZARDOUS
SEAS WILL CONTINUE THROUGH THE MORNING OVER THE OUTER EASTERN
WATERS...BEFORE SUBSIDING BELOW SCA. WILL LIKELY NEED TO EXTEND
THE SCA FOR SEAS INTO FRI MORNING.

FRIDAY NIGHT...N/NW WINDS AND SEAS BELOW SCA.

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.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 AM EST FRIDAY FOR ANZ231-232-251.
     SMALL CRAFT ADVISORY UNTIL 11 PM EST THIS EVENING FOR
     ANZ233>235-237.
     SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR ANZ230-
     236.
     SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ250-254>256.

&&

$$
SYNOPSIS...KJC/EVT
NEAR TERM...KJC
SHORT TERM...KJC
LONG TERM...EVT
AVIATION...KJC/EVT
MARINE...KJC/EVT




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