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000
FXUS61 KBOX 042130
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
430 PM EST WED DEC 4 2013

.SYNOPSIS...
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A RIDGE OF HIGH PRESSURE WILL PUSH OFFSHORE EARLY TONIGHT. A WARM
FRONT WILL BEGIN TO APPROACH LATE TONIGHT. THIS WILL BRING IN LIGHT
PRECIPITATION AS IT SLOWLY CROSSES THE REGION DURING THURSDAY. A
SLOW MOVING COLD FRONT WITH WAVES OF LOW PRESSURE WILL YIELD
PERIODS OF RAIN THURSDAY NIGHT AND FRIDAY...WITH PRECIPITATION
POSSIBLY CHANGING OVER TO SNOW FRIDAY NIGHT. ARCTIC HIGH PRESSURE
BUILDS INTO NEW ENGLAND THIS WEEKEND BRINGING COLDER TEMPS BUT DRY
WEATHER. ANOTHER STORM IS LIKELY EARLY NEXT WEEK BRINGING A WINTRY
MIX OF PRECIPITATION TO THE REGION.
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&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
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OTHER THAN SOME MID AND HIGH CLOUDS ACROSS CENTRAL AND NORTHERN
AREAS...DRY AND SEASONABLE CONDITIONS WERE THE RULE ACROSS THE
REGION TODAY. NOTING A LITTLE LIGHT PRECIP ON RADAR ACROSS N
CENTRAL AND NE MA...BUT TOO LIGHT TO REACH THE GROUND WITH WIDE
TEMP/DEWPT SPREADS IN PLACE.

NOTING MORE CLOUDS APPROACHING FROM THE SW ON IR SATELLITE
IMAGERY...WHICH WILL MOVE NE EARLY TONIGHT AHEAD OF AN
APPROACHING WARM FRONT. NOTING VERY SPOTTY LIGHT PRECIP ALONG
WARM FRONT FROM CENTRAL OH INTO NORTHERN MD AT 20Z...BUT NOTING
GOOD ISENTROPIC LIFT AS FRONT LIFTS NE. SHORT RANGE MODELS DEVELOP
PRECIP OVERNIGHT TO THE SW...THEN MOVES NE. HAVE BROUGHT IN CHANCE
POPS AFTER MIDNIGHT.

HAVE TEMPS FALLING BACK TO THE 30S THROUGH ABOUT MIDNIGHT...THEN
SHOULD START TO SEE READINGS REMAIN STEADY OR START TO RISE LATE.
THE BIGGEST QUESTION AT THIS POINT WILL BE WHETHER ANY PRECIP
MAKES IT INTO NORTHERN PORTIONS OF THE REGION WHILE TEMPS WILL BE
AT OR BELOW FREEZING. ANOTHER QUESTION WILL BE HOW FAST THE TEMPS
WILL RISE...ESPECIALLY WITH THE LIGHT WINDS THAT WILL BE IN PLACE.

PARTIAL THICKNESSES WERE INDICATING FREEZING RAIN AT THE ONSET
FOR A FEW HOURS DURING THE WEE HOURS OF THURSDAY MORNING. EVEN A
LITTLE FREEZING RAIN WILL CAUSE HAVOC ON UNTREATED ROADWAYS...
BRIDGES AND OVERPASSES. BIGGEST CONCERN ARE THE NORTHERN PORTIONS
OF CHESHIRE AND HILLSBOROUGH COUNTIES...SO HAVE ISSUED A FREEZING
RAIN ADVISORY FOR THOSE AREAS. NEW 18Z NAM RUN HAS SLOWED THE
ONSET UNTIL AFTER 10Z ACROSS S NH...BUT MAY BE TOO SLOW. TIMING IS
DEFINITELY AN ISSUE WITH THIS SYSTEM.
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&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...

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THURSDAY...
EXPECT MILDER AIR TO BEGIN STREAMING ACROSS THE REGION AS THE
WARM FRONT SLOWLY WORKS ITS WAY FROM S-N DURING THE DAY. TIMING
REMAINS AN ISSUE AS COLD DOME OF AIR MAY SLOW THINGS DOWN.
HOWEVER...WINDS WILL BEGIN TO PICK UP FROM THE SE...SO SHOULD
ERODE THE COLDER AIR WHILE S-SW WINDS PICK UP FROM H95 AND ABOVE.
GOOD INFLOW OF LOW LEVEL MOISTURE IS IN PLACE BUT NOT TOO MUCH
ABOVE THAT. SO...EXPECT ONLY LIGHT PRECIP AMOUNTS WHICH WILL
CONTINUE OFF AND ON THROUGH THE DAY. WILL ALSO SEE A LOT OF CLOUDS
AND PATCHY FOG. WILL SEE A WIDE RANGE OF TEMPS BY THE END OF THE
DAY...WITH READINGS IN THE MID-UPPER 40S ACROSS S NH/N
MA...RANGING TO THE MID 50S ACROSS INTERIOR CT/S RI AND S COASTAL
MA.

WITH TEMPS CLOSE TO FREEZING EARLY THURSDAY MORNING...SHOULD SEE
THEM RISE JUST ENOUGH TO GO ABOVE FREEZING SO ANY ICING ACROSS S
NH SHOULD END BY 12Z-13Z.

THURSDAY NIGHT...
SHORT RANGE MODEL INDICATE THE WARM FRONT LIFTING N INTO CENTRAL
NEW ENGLAND...JUST AS AN APPROACHING COLD FRONT WORKS OUT OF NY
STATE. BETTER AREA OF LIFT AND MOISTURE INFLOW MOVES IN AHEAD OF
THE FRONT...SO EXPECT LIKELY POPS FOR MOST AREAS THROUGH THE
NIGHT. MODELS TENDING TO SLOW THE FRONT AS IT MOVES INTO THE
REGION OVERNIGHT. WILL ALSO SEE AREAS OF FOG DEVELOP WITH LOW
LEVEL MOISTURE AS WINDS SHIFT TO SW AHEAD OF FRONT. TEMPS WILL
REMAIN MILD...ONLY DROPPING TO THE 40S TO AROUND 50.
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&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
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HIGHLIGHTS...

*  RAIN BUT WARM WITH FRONTAL SYSTEM FRI
*  TEMPS FALL BELOW NORMAL THIS WEEKEND WITH ARCTIC HIGH
*  WINTRY MIX WITH STORM POSSIBLE EARLY NEXT WEEK

OPERATIONAL MODELS ARE IN VERY GOOD AGREEMENT THROUGHOUT MUCH OF THE
LONG TERM PORTION OF THE FORECAST.  THERE ARE A FEW TIMING ISSUES AS
IS THE NORM...NAMELY THAT THE OPERATIONAL GFS IS A BIT FASTER ON THE
STORM FOR EARLY NEXT WEEK.  THIS TIME DIFFERENCE WILL HAVE A BIT
IMPACT ON PTYPE WITH SOME ADJUSTMENTS IN THE TEMPERATURE PROFILE.
REGARDLESS...WITH THE TIME FRAME WE ARE LOOKING AT...WILL GO WITH A
CONSENSUS BLEND HERE.  EXPECT MAINLY RAIN WITH SOME WINTRY PRECIP AT
THE END AS A COLD FRONT MOVES THROUGH THE REGION FRIDAY.  THEN AN
ARCTIC HIGH PRESSURE SYSTEM BUILDS IN FOR THE WEEKEND...WHICH WILL
RESULT IN COLDER...BELOW NORMAL TEMPERATURES FOR EARLY DECEMBER.
THEN ANOTHER FRONTAL SYSTEM EARLY NEXT WEEK...WITH POTENTIAL FOR A
WINTRY MIX OF PRECIP.  BEHIND THE SYSTEM EARLY NEXT WEEK...ANOTHER
STRONG HIGH PRESSURE MAY BUILD INTO THE REGION.

FRIDAY...LOW PRESSURE MOVES ACROSS SOUTHERN CANADA BRINGING A
COLD FRONT THROUGH THE REGION FRIDAY. WITH WARM TEMPERATURES IN
PLACE BOTH AT THE SURFACE AND ALOFT...PRECIPITATION WILL CONTINUE
IN THE FORM OF RAIN FRIDAY...POSSIBLY TRANSITIONING TO A MIX OF
WINTRY PRECIP AS TEMPERATURES FALL BEHIND THE COLD FRONT.
TEMPERATURES SHOULD REMAIN WARM AHEAD OF THE FRONT ON FRIDAY WITH
HIGHS IN THE 40S TO MID 50S.

SATURDAY AND SUNDAY...A STRONG ARCTIC HIGH PRESSURE WILL BUILD
INTO SOUTHERN NEW ENGLAND BRINGING TEMPERATURES AT LEAST 5 TO 10
DEGREES BELOW NORMAL. HOWEVER...MOST OF THE WEEKEND SHOULD BE DRY.
SOME LINGERING SHOWERS ALONG THE SOUTH COAST...CAPE AND
ISLANDS...ARE POSSIBLE EARLY SATURDAY.

SUNDAY NIGHT INTO MONDAY...LOW PRESSURE FROM THE GULF OF MEXICO
MOVES THROUGH THE GREAT LAKES INTO QUEBEC...BRINGING FIRST A WARM
FRONT AND THEN A COLD FRONT THROUGH SOUTHERN NEW ENGLAND. THE
EXACT TIMING OF THIS REMAINS IN QUESTION AMONGST THE GFS AND ECMWF
OPERATIONAL MODELS...AND WILL ULTIMATELY DETERMINE PTYPE...
PARTICULARLY AT THE ONSET SOMETIME SUNDAY NIGHT INTO MONDAY
MORNING. AS STATED ABOVE...WILL USE A BLEND OF THE MODELS FOR
THIS TIME PERIOD.

TUESDAY AND WEDNESDAY...DEPENDING ON THE TIMING OF THE FRONTAL
SYSTEM...PRECIP COULD LINGER INTO TUESDAY. OTHERWISE...ANOTHER
COLD HIGH PRESSURE STARTS TO BUILD INTO SOUTHERN NEW ENGLAND.
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&&

.AVIATION /21Z WEDNESDAY THROUGH MONDAY/...
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FORECASTER CONFIDENCE LEVELS...

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

HIGH CONFIDENCE THROUGH MIDNIGHT...THEN MODERATE CONFIDENCE
OVERNIGHT THROUGH THURSDAY NIGHT.

THIS AFTERNOON...VFR. GENERALLY LIGHT W-NW WINDS.

TONIGHT...MAINLY VFR. MVFR CIGS/VSBYS MOVE INTO N CENTRAL CT/W MA
AFTER MIDNIGHT...THOUGH SOME QUESTION WITH TIMING. LOW CHANCE OF
LIGHT RAIN MOVING INTO WESTERN AREAS AFTER MIDNIGHT. MAY SEE BRIEF
PERIOD OF -FZRA ACROSS S NH AT ONSET OF PRECIP.

THURSDAY-THURSDAY NIGHT...MVFR-IFR CIGS/MVFR VSBYS THU...LOWERING
TO GENERAL IFR CONDITIONS WITH AREAS OF LIFR CIGS IN -RA AND FOG
THU NIGHT. LOWER CONFIDENCE ON TIMING.

KBOS TAF...HIGH CONFIDENCE IN TAF...BUT LOWER TIMING THE ARRIVAL
OF MVFR-IFR CONDITIONS THU.

KBDL TAF...HIGH CONFIDENCE IN TAF...BUT LOWER TIMING THE ARRIVAL
OF MVFR CONDITIONS TONIGHT AND THEN IFR THU.

OUTLOOK...FRIDAY THROUGH MONDAY...

FRIDAY...MODERATE TO HIGH CONFIDENCE.  MVFR/IFR CONDITIONS EXPECTED
TO DOMINATE IN PERIODS OF RAIN AND FOG.  RAIN MAY TURN TO A WINTRY
MIX OF PRECIPITATION FRIDAY NIGHT.

SATURDAY AND SUNDAY...HIGH CONFIDENCE.  CONDITIONS IMPROVE TO VFR
SATURDAY MORNING...THOUGH WILL BE SLOWEST TO IMPROVE ALONG THE SOUTH
COAST...CAPE...AND ISLANDS.

SUNDAY NIGHT AND MONDAY...LOW CONFIDENCE.  MVFR/IFR CONDITIONS
LIKELY IN A WINTRY MIX OF PRECIPITATION AND FOG.
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&&

.MARINE...
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FORECASTER CONFIDENCE LEVELS...

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

HIGH CONFIDENCE THROUGH THURSDAY NIGHT.

THROUGH THIS EVENING...EASTERLY SWELLS HAVE FINALLY SUBSIDED
ACROSS THE EASTERN OUTER WATERS...SO ENDED THE SMALL CRAFT
ADVISORY.

TONIGHT...EXPECT LIGHT/VRBL WINDS TO BECOME SE AS WARM FRONT
APPROACHES. WINDS AND SEAS REMAIN BELOW SMALL CRAFT CRITERIA.
AREAS OF FOG...DRIZZLE AND LIGHT RAIN DEVELOP FROM S-N
OVERNIGHT WITH VSBY RESTRICTIONS.

THURSDAY-THURSDAY NIGHT...EXPECT S-SE WINDS TO PICK UP AS THEY
SHIFT TO SW WITH WARM FRONTAL PASSAGE DURING THURSDAY. WINDS MAY
GUST UP TO 20 KT THU NIGHT AHEAD OF APPROACHING COLD FRONT. SEAS
MAY BUILD UP TO 5-6 FT ON THE OUTER WATERS THU NIGHT...SO SMALL
CRAFTS MAY BE NEEDED AGAIN.

OUTLOOK...FRIDAY THROUGH MONDAY...

FRIDAY...HIGH CONFIDENCE.  6 TO 8 FOOT SEAS DURING THE MORNING WILL
SLOWLY DIMINISH AS HIGH PRESSURE STARTS TO BUILD INTO THE REGION
BEHIND A COLD FRONT.  SOUTHWESTERLY WINDS SHIFT TO THE NORTH-
NORTHWEST FRIDAY EVENING AS A COLD FRONT CROSSES THE WATERS.  AN
INVERSION KEEPS WINDS JUST BELOW SMALL CRAFT CRITERIA.  HOWEVER...
WITH SEAS 5 TO 8 FEET...PARTICULARLY ON THE OUTER WATERS...WILL
LIKELY NEED SMALL CRAFT ADVISORIES.

SATURDAY THROUGH SUNDAY...MODERATE CONFIDENCE.  SEAS CONTINUE TO
DIMINISH GRADUALLY AS AN ARCTIC HIGH PRESSURE BUILDS OVER THE
REGION. NORTHWESTERLY WINDS GUST TO AROUND 20 KTS WITH STRONG COLD
ADVECTION OVER THE WATERS.

SUNDAY NIGHT AND MONDAY...LOW CONFIDENCE.  DEPENDING ON THE TIMING
OF ANOTHER FRONTAL SYSTEM...WINDS AND SEAS BEGIN TO
INCREASE...REACHING SMALL CRAFT CRITERIA LATE SUNDAY NIGHT.
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&&

.BOX WATCHES/WARNINGS/ADVISORIES...
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CT...NONE.
MA...NONE.
NH...FREEZING RAIN ADVISORY FROM 2 AM TO 7 AM EST THURSDAY FOR
     NHZ011-015.
RI...NONE.
MARINE...NONE.
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&&

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