Area Forecast Discussion
Issued by NWS Boston, MA

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FXUS61 KBOX 241158
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
658 AM EST MON NOV 24 2014

.SYNOPSIS...
A WARM FRONT WILL BRING A BRIEF PERIOD OF HEAVY RAIN AND STRONG
WINDS ALONG THE SOUTHEAST COAST THIS MORNING...FOLLOWED BY
UNSEASONABLY MILD CONDITIONS MONDAY AFTERNOON. QUIET AND MILD
TUESDAY WITH SOME GUSTY SW WINDS. STORM SYSTEM ANTICIPATED
WEDNESDAY INTO THURSDAY MORNING...YET TRACK AND EFFECTS REMAIN
UNCERTAIN. GRADUALLY TURNING COLDER INTO THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
***BRIEF PERIOD OF HEAVY RAIN THIS MORNING ALONG WITH STRONG WINDS
 ACROSS SOUTHEAST NEW ENGLAND***

645 AM UPDATE...
AXIS OF RAINFALL RACING EAST ACROSS SNE THIS MORNING. DRY SLOT
ALREADY MOVING INTO WESTERN NEW ENG AND HEAVIEST RAIN IS BEGINNING
TO MOVE EAST OF CT VALLEY. LOOKING AT JUST A 2-3 HOUR PERIOD OF
MODERATE TO HEAVY RAINFALL THIS MORNING BEFORE DRY SLOT MOVES IN
AND RAIN TAPERS OFF FROM WEST TO EAST MID TO LATE MORNING. TEMPS
HAVE RISEN INTO THE 50S IN THE COASTAL PLAIN BUT COOLER AIR
HANGING TOUGH IN THE CT VALLEY WHERE STILL UPPER 30S TO LOWER 40S.
THIS COOL AIR WILL QUICKLY MIX OUT NEXT HOUR OR SO WITH TEMPS
RISING QUICKLY THROUGH THE 50S. SEEING WIND GUSTS TO 25-30 KT NEAR
THE S COAST. POTENTIAL FOR G35-40 KT SE NEW ENG THROUGH 18Z AS LLJ
MOVES ACROSS THE REGION.

PREVIOUS DISCUSSION...
POTENT LOW LEVEL JET +4SD WILL TRANSPORT ANOMALOUS PWATS /+3 TO
+4SD/ NORTH INTO THE REGION TO BRING A PERIOD OF HEAVY RAINFALL TO
THE REGION. ELEVATED THUNDER INDICES ARE MARGINAL AT BEST BUT CANT
RULE OUT AN ISOLD TSTM IN THE COASTAL PLAIN AS THE NOSE OF LLJ
MOVES ACROSS THE REGION. SYSTEM IS RATHER PROGRESSIVE AND NOTE
THAT DRY SLOT IS ALREADY MOVING INTO CENTRAL PA SO DURATION OF
STEADIEST RAINFALL WILL BE SHORT LIKELY LASTING NO MORE THAN 6
HOURS...WITH RAIN TAPERING OFF 13-16Z FROM WEST TO EAST. THIS WILL
LIMIT QPF WITH RAINFALL AMOUNTS AVERAGING 0.50-1.00 ACROSS THE
REGION WITH LOCALLY HIGHER AMOUNTS. JUST THE TYPICAL NUISANCE POOR
DRAINAGE STREET FLOODING IS ANTICIPATED.

STRONG WIND POTENTIAL ALONG SE NEW ENG COAST...
FAIRLY POTENT LOW LEVEL JET 70-75 KT AT 925 MB WILL BE MOVING
ACROSS SE NEW ENG 12-18Z. HOWEVER LOW LEVEL INVERSION IS PRESENT
AT THE TIME THE JET IS MOVING THROUGH SO THIS WILL LIMIT HOW MUCH
OF THIS WIND CAN MIX DOWN TO THE SURFACE IN THE ABSENCE OF ANY
FINE LINE OF CONVECTION. AND THIS IS NOT REALLY AN IDEAL SITUATION
FOR A FINE LINE GIVEN MARGINAL INSTABILITY AND NO COLD FRONT.
TAKING ABOUT 50 PERCENT OF THE MAGNITUDE OF THE JET OFTEN IS A
DECENT STARTING POINT FOR ESTIMATING GUST POTENTIAL WITH THESE
SOUTHERLY LOW LEVEL JETS WITH INVERSION IN PLACE. THIS SUGGESTS
POTENTIAL FOR G35-40 KT WHICH IS RIGHT NEAR THE THRESHOLD OF WIND
ADVISORY CRITERIA SO WE WILL CONTINUE THE ADVISORY FOR THE CURRENT
AREA. HOWEVER...BEST CHANCE OF REALIZING GUSTS TO 45+ MPH WILL BE
OVER CAPE/ISLANDS AND AREAS NEAR THE CAPE COD CANAL IN SE MA.

THIS AFTERNOON...
DRY SLOT WILL HAVE MOVED ACROSS THE REGION BY MIDDAY WITH RAINFALL
EXITING THE REGION...BUT PLENTY OF LOW LEVEL MOISTURE IN PLACE
WHICH WILL KEEP LOW CLOUDS ACROSS THE REGION WITH A FEW PASSING
SHOWERS POSSIBLE. IT WILL BE WINDY AS STRONG LOW LEVEL WINDS
REMAIN ACROSS THE REGION. SW WIND GUSTS 25-35 MPH EXPECTED AND
POSSIBLY UP TO 40 MPH SE NEW ENG. 925 MB TEMPS 13-15C SO IT WILL
BE A RATHER MILD DAY FOR LATE NOVEMBER WITH TEMPS REACHING THE
MID 60S ACROSS MANY LOCATIONS. 70 DEGREES WOULD BE POSSIBLE IF WE
COULD GET SOME SUNSHINE BUT THIS DOESNT APPEAR LIKELY.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
WEAK COLD FRONT WILL BE MOVING INTO THE REGION SO CANT RULE OUT A
FEW SHOWERS. OTHERWISE AREAS OF LOW CLOUDS WILL LINGER INTO THE
EVENING BEFORE PARTIAL MOVES IN FROM THE WEST OVERNIGHT. IT WILL
BE AN UNSEASONABLY MILD MIGHT AS LOW LEVEL COOLING DOESNT MOVE
INTO THE REGION TIL LATE TONIGHT. MINS WILL BE IN THE 50S ACROSS
MUCH OF THE REGION...EXCEPT 40S FAR W WHERE COOLING ARRIVES
EARLIER. GUSTY SW WINDS WILL CONTINUE INTO THE EVENING BEFORE
DIMINISHING OVERNIGHT.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
* PLOWABLE SNOW STORM LIKELY WEDNESDAY...EXACT TRACK AND LOCATION OF
  RAIN/SNOW LINE STILL QUITE UNCERTAIN
* COLDER TEMPERATURES EXPECTED TOWARDS THE WEEKEND
* LOW CONFIDENCE IN ANOTHER STORM LATE IN THE WEEKEND

MAIN CONCERN THROUGH THE LONG TERM IS THE POTENTIAL FOR A WINTER
STORM WEDNESDAY INTO THANKSGIVING.  UNFORTUNATELY...MODELS ARE
STRUGGLING WITH THIS STORM...PARTICULARLY THE TRACK OF THE LOW WHICH
WILL AFFECT EVERYTHING FROM AMOUNT AND TYPE OF PRECIPITATION TO
TEMPERATURE GRADIENTS...WHICH WILL IN TURN AFFECT THE TYPE OF
PRECIPITATION.  THE ENSEMBLES HAVE THE LOW TRACKING ANYWHERE FROM
OVER PENNSYLVANIA TO OUT TO SEA WITH THE OPERATIONAL MODELS
SOMEWHERE IN BETWEEN.  THE MOST LIKELY SOLUTIONS APPEAR TO BE
TRACKING OVER SOUTHERN NEW ENGLAND /AT THE WESTERN END OF THE
ENVELOPE/ TO JUST OUTSIDE THE 40/70 BENCHMARK /AT THE EASTERN END OF
THE ENVELOPE.  OUTSIDE OF THIS TIME FRAME THE MODELS ARE IN
AGREEMENT THROUGH THE WORK WEEK WITH MORE DISCREPANCIES SEEN WITH
THE WEEKEND FORECAST.  THE GFS IS FORECASTING ANOTHER ROUND OF
PRECIP WITH A COLD FRONT APPROACHING SOUTHERN NEW ENGLAND.  THIS IS
VERY LOW CONFIDENCE AT THIS POINT THOUGH.

TUESDAY...ANOTHER RELATIVELY WARM DAY EXPECTED THOUGH IT WILL BE A
FEW DEGREES COOLER THAN MONDAY.  TEMPERATURES WILL BE RIGHT AROUND
TO A LITTLE ABOVE NORMAL.  LOW PRESSURE IN QUEBEC WILL MOVE INTO THE
MARITIMES PULLING A COLD FRONT THROUGH SOUTHERN NEW ENGLAND.  A
SOUTHWESTERLY 40 TO 50 KT LOW LEVEL JET WITH DECENT MIXING WILL
ALLOW FOR SOME GUSTY WINDS BUT THESE ARE EXPECTED TO REMAIN BELOW
ADVISORY LEVELS.

WEDNESDAY THROUGH THANKSGIVING MORNING...AS STATED ABOVE...THIS WILL
BE THE FOCUS OF THE FORECAST AND IS ALSO THE MOST UNCERTAIN.  LOW
PRESSURE WILL MOVE UP THE COAST MOST LIKELY MOVING ANYWHERE FROM
DIRECTLY OVER SOUTHERN NEW ENGLAND TO JUST OUTSIDE THE 40/70
BENCHMARK.  A TRACK OF THIS SORT IS LIKELY TO BRING A PLOWABLE SNOW
TO AT LEAST A PORTION OF SOUTHERN NEW ENGLAND. WHILE THERE IS STILL
QUITE A BIT OF UNCERTAINTY WITH THE TRACK...AM CONFIDENT ENOUGH IN
SIX INCHES OF SNOW FALLING ACROSS WESTERN MASSACHUSETTS AND NORTHERN
CONNECTICUT TO ISSUE A WINTER STORM WATCH FOR THESE AREAS.
ESPECIALLY SINCE THIS IS THE BUSIEST TRAVEL DAY OF THE YEAR AND
LIKELY TO AFFECT MANY.

THE ECMWF IS THE FARTHEST WEST OF THE OPERATIONAL MODELS AND BRINGS
AT LEAST THREE-QUARTERS OF AN INCH OF QPF OVER THE WESTERN AREAS.
WHILE THE GFS IS FARTHER TO THE EAST...IT TOO BRINGS AT LEAST THREE
QUARTERS OF AN INCH OF QPF OVER THE WESTERN AREAS AND HAS A COLDER
THERMAL PROFILE. THIS WOULD RESULT IN AT LEAST SIX INCHES OF SNOW AT
LEAST OVER THE WESTERN AREAS AND LIKELY FARTHER EAST.  THIS IS
DEFINITELY A STORM TO WATCH.

WHILE THE LOCATION OF THE RAIN/SNOW LINE CANNOT BE DETERMINED AT
THIS POINT...APPEARS LIKELY THAT IT WILL BE SOMEWHERE NEAR OR WEST
OF THE INTERSTATE 95 CORRIDOR.  A FEW SNOW SHOWERS MAY LINGER INTO
THANKSGIVING MORNING BEFORE THE LOW PRESSURE PULLS AWAY FROM
SOUTHERN NEW ENGLAND.

THANKSGIVING AFTERNOON THROUGH FRIDAY...HIGH PRESSURE BUILDS INTO
SOUTHERN NEW ENGLAND RESULTING IN COOLER TEMPERATURES BUT QUIET
WEATHER.

SATURDAY AND SUNDAY...LESS CERTAINTY IN THIS PART OF THE FORECAST.
HIGH PRESSURE SATURDAY WILL MOVE OFFSHORE ALLOWING A LOW PRESSURE
SYSTEM TO AFFECT A PORTION OF SOUTHERN NEW ENGLAND SUNDAY.

&&

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

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

.SHORT-TERM /THROUGH TONIGHT/...MODERATE CONFIDENCE.

TODAY...MVFR/IFR IN MODERATE TO HEAVY RAIN. STEADY RAIN EXITS
13-16Z WITH A FEW SHOWERS POSSIBLE IN THE AFTERNOON...BUT MVFR/IFR
CIGS WILL PERSIST. S WIND GUSTS TO 35-40 KT POSSIBLE ACROSS SE NEW
ENG AND ESPECIALLY CAPE/ISLANDS 12-16Z...THEN SW GUSTS TO 25-35 KT
DURING THE AFTERNOON. LLWS LIKELY AS 2K FT WINDS 45-55 KT.

TONIGHT...MVFR-IFR CONDITIONS GRADUALLY IMPROVE TO VFR IN THE
EVENING ACROSS W AND N TERMINALS...BUT NOT UNTIL AFT 06Z ACROSS
SE NEW ENG. BLUSTERY SW WIND GUSTS 25-35 KT IN THE EVENING
DIMINISHING OVERNIGHT.

KBOS TERMINAL...MODERATE CONFIDENCE. A PERIOD OF IFR CIGS POSSIBLE
BUT NOT IN TAF AS CONFIDENCE IS LOW WITH GUSTY S WINDS. LLWS
LIKELY TODAY WITH 50 KT AT 2K FT.

KBDL TERMINAL...MODERATE CONFIDENCE. LLWS LIKELY.

OUTLOOK...TUESDAY THROUGH FRIDAY.

TUESDAY...HIGH CONFIDENCE. VFR. SW WINDS GUST TO 25KTS.

WEDNESDAY INTO THU AM...LOW CONFIDENCE.  MVFR/IFR CONDITIONS IN
SNOW/RAIN.  GREATEST LIKELIHOOD OF SNOW...INCLUDING HEAVY SNOW...IS
WEST OF WORCESTER THROUGH WESTERN MASSACHUSETTS AND NORTHERN
CONNECTICUT.

THU PM THROUGH FRI...MODERATE CONFIDENCE.  VFR.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

.SHORT TERM /THROUGH TONIGHT/...MODERATE CONFIDENCE.

STRONG LOW LEVEL JET WILL BRING SOUTHERLY GALE FORCE WIND GUSTS
TO THE WATERS TODAY. WHILE INVERSION IS PRESENT WHICH WILL LIMIT
STRONGEST WINDS FROM MIXING DOWN STILL THINK GUSTS TO 35-40 KT
POSSIBLE SO GALE WARNINGS WILL CONTINUE. SW GALES WILL LINGER INTO
THE EVENING ACROSS THE OUTER WATERS BEFORE DIMINISHING OVERNIGHT.
SEAS WILL BUILD TO BETWEEN 10 AND 15 FEET ACROSS THE SOUTHERN
WATERS. REDUCED VSBYS THIS MORNING IN RAIN AND FOG.

OUTLOOK...TUESDAY THROUGH FRIDAY.

TUESDAY...SOUTHWEST SCA WINDS SHIFT TO THE NORTHWEST AS A COLD FRONT
CROSSES THE WATERS...THEN WINDS AND SEAS DIMINISH AS HIGH PRESSURE
BUILDS OVER THE WATERS.

WEDNESDAY...SEAS INCREASE AS LOW PRESSURE MOVES OVER OR NEAR THE
COASTAL WATERS.  NORTHWESTERLY GALES LIKELY.

THURSDAY AND FRIDAY...SEAS DIMINISH AS HIGH PRESSURE BUILDS OVER THE
WATERS. WESTERLY WINDS GUST TO 25 KTS.

&&

.TIDES/COASTAL FLOODING...
ASTRONOMICAL TIDES ARE FAIRLY HIGH DURING THIS MORNINGS HIGH TIDE
CYCLE. WITH SOUTHERLY GALES EXPECTED...A STORM SURGE OF 1.5 TO 2
FT IS LIKELY ALONG THE SOUTH COAST WITH HIGHEST SURGE EXPECTED IN
NARRAGANSETT BAY. THIS MAY BRING A FEW LOCATIONS TO MINOR FLOOD.
THE MAIN THREAT FOR MINOR COASTAL FLOODING WILL BE ALONG
NARRAGANSETT BAY AND WESTPORT HARBOR DUE TO SOUTHERLY FETCH.
COASTAL FLOOD ADVISORIES CONTINUE FOR THE SOUTH COAST. NO
FLOODING IS EXPECTED ALONG THE EAST COAST.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WINTER STORM WATCH FROM WEDNESDAY MORNING THROUGH THURSDAY
     MORNING FOR CTZ002>004.
MA...WIND ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR MAZ018>024.
     COASTAL FLOOD ADVISORY UNTIL 11 AM EST THIS MORNING FOR
     MAZ020>022.
     WINTER STORM WATCH FROM WEDNESDAY MORNING THROUGH THURSDAY
     MORNING FOR MAZ002>004-008>012-026.
NH...NONE.
RI...WIND ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR RIZ003>008.
     COASTAL FLOOD ADVISORY UNTIL 11 AM EST THIS MORNING FOR RIZ002-
     004>007.
MARINE...GALE WARNING UNTIL 10 PM EST THIS EVENING FOR ANZ231>235-237-
     250-254>256.
     SMALL CRAFT ADVISORY UNTIL 1 AM EST TUESDAY FOR ANZ230.
     GALE WARNING UNTIL 4 PM EST THIS AFTERNOON FOR ANZ236.
     GALE WARNING UNTIL 6 PM EST THIS EVENING FOR ANZ251.

&&

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


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