FXUS61 KBOX 071526
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
1026 AM EST MON DEC 7 2009

.SYNOPSIS...
HIGH PRESSURE MOVES OFFSHORE TODAY AND WILL BE FOLLOWED BY WEAK LOW
PRESSURE TONIGHT. HIGH PRESSURE RETURNS TUESDAY...THEN A LARGE STORM 
WILL AFFECT SOUTHERN NEW ENGLAND WEDNESDAY WITH MIXED PRECIPITATION
AND WIND. COLDER THAN NORMAL AND BLUSTERY WEATHER WILL FOLLOW IN THE
WAKE OF THE STORM FOR THE END OF THE WEEK AND INTO NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
1025: DOWNWARD GLIDE SLOPE FCST ADJUSTMENT ON TEMPS AGAIN THROUGH MIDDAY
AS THEY ARE SLOW TO RISE IN PARTS OF INTERIOR SNE. THE DEWPOINTS WERE
ADJUSTED UP THRU MID AFTN. ALSO HAVE ADJUSTED POPS WITH THE 12Z SREF
AND GOING LIKELY ON THE CAPE. UNSTABLE LAPSE RATE CU ARE MOVING NNE
FROM S OF BID AND ITS PROBABLE THAT IT WILL RAIN AND THEN END AS SNOW
SHOWERS ON CAPE COD TONIGHT. THE FCST WILL POST ARD 1050 AM AS SOON
AS WE REVIEW THE 12Z GFS. 

830AM: FCST BASICALLY ON TRACK IN THIS EARLY MORNING FIRST PART OF
THE SHIFT REVIEW. WE'VE ADJUSTED GLIDE SLOPES OF TT/TD WHERE TEMPS
ARE RUNNING SLIGHTLY COLDER AT 8AM THAN PREDICTED. THOSE SHOULD GET
BACK ON TRACK BY 10 AM. DEWPOINTS WERE SLIGHTLY HIGHER THAN MODELED
AND THOSE HAVE BEEN INCREASED THROUGH 19Z MOST OF MA/CT/RI.

WINDEX EVENT DEVELOPING FOR LATE THIS AFTN...TYPICALLY IN THE PAST THE
MODELS HAVE UNDERPLAYED THIS BUT IT SEEMS THAT THE MODELS HAVE DONE A
BETTER JOB THE PAST 6 DAYS WITH INDICATING THE POTENTIAL.  IN THIS CASE
THINK THE HEAVIEST QPF WILL BE SE MA CAPE AND ISLANDS WHERE BL
SATURATION COMBINES WITH INCREASINGLY STEEP LOW LVL LAPSE RATES TO
DEVELOP NEWD DEVELOPING SHWRS FROM THE OCEAN NEWD ACROSS SE NEW
ENGLAND LATE TODAY. OKX/BOX RADAR SHOULD SHOW THIS S OF LONG ISLAND 
DEVELOPMENT DURING EARLY AND MID AFTN. BLV THE BL WARM ENOUGH SE NEW
ENGLAND FOR RAIN AT THE START THEN CHANGING TO SNOW AND POSSIBLE
SLIPPERY COVERING UNDER ONE HALF INCH SE MASS PYM TO EWB AND MAYBE
UPPER CAPE.

OTRW...PER THE MID SHIFT BELOW...
CLOUDS WILL CONTINUE TO INCREASE TODAY AND HIGH PRESSURE MOVES
OFFSHORE AND A WEAK SHORT WAVE TROUGH APPROACHES FROM THE WEST.
ENOUGH WAA-DRIVEN ASCENT MAY DEVELOP TO ALLOW FOR A FEW FLURRIES OR
SNOW SHOWERS AND ACROSS NW MA AND S NH LATE IN THE AFTN. AS THE SHORT
WAVE APPROACHES THE COAST LATER IN THE DAY...WEAK SECONDARY SURFACE
LOW PRESSURE WILL PROBABLY DEVELOP NEAR THE CAPE AND ISLANDS. THIS
WILL PROBABLY AID THE DEVELOPMENT OF WINDEX PCPN AS OUTLINED IN THE
PGH ABOVE. 
'
WE HAVE SLIGHT CHANCE TO LOW CHANCE POPS GOING FOR LATER THIS
AFTERNOON...MAINLY ALONG AND EAST OF THE I-95 CORRIDOR AND MAY
BOOST IN THE 1130AM.

AS FAR AS TEMPERATURES GO...WE EXPECT THAT MOS TEMPERATURES WILL BE
TOO HIGH ONCE AGAIN TODAY DUE TO SNOW COVER AND LITTLE MIXING.
THEREFORE...WE CUT BACK ON MOS A BIT. THIS RESULTS IN HIGH
TEMPERATURES ABOUT 5 DEGREES BELOW NORMAL.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
CLUSTERS OF SNOW SHOWERS OR R CHANGING TO SNOW SHOWERS ACROSS COASTAL
MASS WILL MOVE OUT TO SEA DURING THE EVENING HOURS AS LOW PRESSURE
MOVES AWAY FROM THE SOUTHERN NEW ENGLAND COAST. AT LEAST PARTIAL
CLEARING SHOULD OCCUR TONIGHT IN THE WAKE OF THE SHORT WAVE TROUGH.

OVERALL...AN UNEVENTFUL DAY IS IN STORE WEATHER WISE FOR SOUTHERN NEW
ENGLAND ON TUESDAY. SURFACE HIGH PRESSURE BUILDS IN FROM THE WEST
ALLOWING FOR PARTLY TO MOSTLY SUNNY SKIES AND MAX TEMPS AROUND 5
DEGREES BELOW NORMAL. THE SURFACE PRESSURE GRADIENT WILL LOOSEN UP AS
THE DAY PROGRESSES...THEREFORE WINDS WILL TEND TO DIMINISH.

TUE NIGHT...HIGH PRES WILL BE OVER NEW ENG TUE EVENING THEN RETREAT 
NE AS OVERRUNNING MOISTURE APPROACHES FROM THE SW.  NAM IS SLOW 
OUTLIER WITH ONSET OF PRECIP AND ALL OTHER MODELS ARE QUICKER MOVING 
PRECIP INTO AT LEAST W ZONES LATE TUE NIGHT.  DISCOUNTED THE NAM AS 
FASTER SOLUTION SEEMS MORE REASONABLE WITH APPROACHING LLJ AND 
INCREASING ISENTROPIC LIFT.  GENERALLY FOLLOWED SREF POPS WHICH LOOK 
GOOD FOR TIMING.  COLUMN IS COLD ENOUGH FOR ANY PRECIP TUE NIGHT TO 
BEGIN AS SNOW.  EXCEPTION IS ALONG THE SOUTH COAST WHERE INCREASING 
ELY FLOW WILL QUICKLY WARM BL WITH MAINLY RAIN OR MIX RAIN/SNOW.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
WED...SIGNIFICANT STORM WILL AFFECT SNE WITH HEAVY PRECIP AND STRONG
WIND ALONG THE COAST. MODELS IN GOOD AGREEMENT WITH INTENSE PRIMARY
LOW MOVING NE INTO THE GT LAKES WED WITH SECONDARY WAVE DEVELOPING ON
THE WARM FRONT AND LIFTING NWD INTO SNE. VERY STRONG ISENTROPIC LIFT
WILL MOVE NWD INTO THE REGION AND QPF 1-2" POSSIBLE. COLD AIR
INITIALLY IN PLACE IN THE INTERIOR AS STRONG OMEGA MOVES IN SUGGESTS
A PERIOD OF HEAVY SNOW LIKELY INTERIOR BEFORE LOW LEVEL WARMING
CHANGES THE PRECIP TO RAIN WITH S NH LAST TO SEE CHANGEOVER EARLY WED
AFTERNOON.

THERMAL PROFILE AND BEST SNOW GROWTH TARGETS AREA FROM ORH NORTHWARD 
THROUGH S NH FOR HEAVIEST SNOW ACCUM.  THERE IS A CHANCE THIS REGION 
COULD END UP WITH WARNING CRITERIA SNOWFALL BUT HIGH PROB OF AT 
LEAST ADVSY SNOWFALL.  LIGHTER SNOW ACCUM WITH LOW PROB OF ADVSY 
SNOWFALL EXPECTED REST OF INTERIOR FROM BOS SUBURBS THROUGH NW RI 
AND N CT.   LITTLE OR NO ACCUM EXPECTED ALONG AND SE OF BOS-PVD.  
ALSO NOT EXPECTING MUCH ICE IN THE INTERIOR DURING THE TRANSITION 
FROM SNOW TO RAIN AS SOUNDINGS SHOW DEEP LAYER WARMING ABOVE 
FREEZING.  

WIND IS THE OTHER CONCERN FOR WED AS STRONG EASTERLY LLJ LIFTS 
NORTHWARD WITH VERY STRONG PRESSURE FALLS.  STRONGEST WINDS WILL 
LIKELY BE FROM CAPE COD NORTHWARD ALONG E COASTAL MA AND WIND ADVSY 
WILL PROBABLY BE NEEDED.  LOW PROB OF HWW OUTER CAPE.  

PRECIP TAPERS OFF LATE WED AND ESPECIALLY WED EVENING AS OCCLUSION
LIFTS TO THE NORTH AND DRY SLOT MOVES IN ALONG WITH WIND SHIFT TO THE
SW.

THU...GUSTY WEST WINDS WITH COLDER AIR MOVING INTO THE REGION.  
LOWERED MEX GUIDANCE ABOUT 5 DEGREES BASED ON 2M TEMPS.  A FEW 
FLURRIES POSSIBLE NW HIGHER TERRAIN.   

COLD AND BLUSTERY FRI AND SAT WITH GUSTY W WINDS CONTINUING.  850 MB 
TEMPS AROUND -16C SO TEMPS SEVERAL DEGREES BELOW NORMAL AND WIND 
CHILLS WILL BECOME A FACTOR.  A FEW FLURRIES/SNOW SHOWERS POSSIBLE 
FROM TIME TO TIME BUT KEPT POPS IN SLIGHT CHC CATEGORY.  

SUN...EC HAS CLOSE CALL WITH OCEAN STORM TO THE SOUTH AS COLD FRONT 
MOVES INTO REGION.  GFS HAS HIGH PRESSURE.  KEPT A DRY FORECAST FOR 
NOW WITH BELOW NORMAL TEMPS CONTINUING.

&&

.AVIATION /16Z MONDAY THROUGH FRIDAY/...
TODAY...VFR. MVFR CIGS IN ISOLD/SCT RAIN/SNOW SHOWERS LATE AFTN SE
MASS CAPE AND ISLANDS..AFTER 21Z.

MVFR CIGS AND WIDELY SCATTERED RAIN/SNOW SHOWERS IN SEASTERN MASS
DURING THE EVENING. CLEARING SKIES AFTER MIDNIGHT.

TUESDAY...VFR.

TUE NIGHT...MAY LOWER TO MVFR/IFR LATE IN DEVELOPING SNOW W ZONES
WITH RAIN ALONG THE COAST.

OUTLOOK /WEDNESDAY THROUGH FRIDAY/...

WEDNESDAY...WIDESPREAD IFR/LIFR LIKELY IN SNOW CHANGING TO RAIN 
INTERIOR AND HEAVY RAIN COAST.  STRONG E WINDS ALONG THE COAST.

THURSDAY AND FRIDAY...MAINLY VFR BUT STRONG WEST WINDS LIKELY.

&&

.MARINE...
TODAY...WILL UPDATE THE CWF BY 1115 AM FOR HEADLINE CHG. RELATIVELY
TRANQUIL CONDITIONS ARE EXPECTED.

TONIGHT AND TUESDAY...RELATIVELY WEAK PRESSURE GRADIENT SHOULD RESULT
IN SUB-SCA CONDITIONS ON MOST MARINE ZONES. LOW PROB FOR THE
REAPPEARANCE OF MARGINAL SCA SEAS ON THE SOUTH COASTAL OCEAN WATERS
LATE TONIGHT INTO TUESDAY MORNING.

OUTLOOK /WEDNESDAY THROUGH FRIDAY/...

EAST WINDS INCREASING LATE TUE NIGHT AND STRONG GALES LIKELY DURING 
WED...ESPECIALLY E MA COASTAL WATERS AS STRONG LLJ LIFTS NORTHWARD.  
THERE IS ALSO A LOW PROB OF STORM FORCE WINDS WED AFTERNOON OVER 
OUTER WATERS NORTH AND EAST OF CAPE COD.

EXTENDED PERIOD OF GALE FORCE WESTERLY WINDS LIKELY TO PERSIST WED 
NIGHT THROUGH FRIDAY WITH STRONG GRADIENT AND CAA.  WINDS INITIALLY 
BECOME SW WED EVENING BEHIND OCCLUSION BEFORE TURNING MORE WEST.

&&

.CLIMATE...
BOSTON/S LOGAN AIRPORT FINALLY HIT THE FREEZING MARK SUNDAY MORNING FOR
THE FIRST TIME SINCE MARCH 26TH 2009. THE LOW THIS SUNDAY MORNING
WAS 31 DEGREES AT 804 AM. IN 137 YEARS OF RECORD KEEPING...THIS IS
THE LONGEST BOSTON HAS EVER WAITED TO GET DOWN TO THE FREEZING MARK
DURING THE AUTUMN/WINTER. THE PREVIOUS RECORD WAS DECEMBER 2ND 1975.
THIS CAN BE ATTRIBUTED TO HAVING THE 6TH WARMEST NOVEMBER ON
RECORD...THE URBAN HEAT ISLAND EFFECT...AND PROBABLY A LITTLE LUCK.
ON AVERAGE...THE FIRST FREEZE TYPICALLY OCCURS THE FIRST WEEK OF
NOVEMBER.

&&

.EQUIPMENT...
GLOUCESTER NWR TRANSMITTER IS OFF THE AIR. RTS UNKNOWN. 
WE ARE WORKING ON THE PROBLEM. JOHNSTON/PROVIDENCE NWR TRANSMITTER
IS BACK ON THE AIR BUT ON LOW POWER...SOME SOUTH COASTAL LOCATIONS
MAY BE UNABLE TO RECEIVE THE SIGNAL. MORE MAINTENANCE WILL BE DONE ON
MONDAY TO RETURN THIS STATION TO FULL POWER. IN THE MEANTIME...PLEASE
SEE OUR WEBSITE... WWW.WEATHER.GOV/BOSTON FOR WEATHER INFORMATION.

&&

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

&&

$$
SYNOPSIS...KJC/DRAG/EKSTER 1025A
NEAR TERM...DRAG/EKSTER 1025A
SHORT TERM...DRAG/EKSTER
LONG TERM...KJC
AVIATION...KJC/DRAG/EKSTER 1025A
MARINE...KJC/DRAG/EKSTER 1025A
CLIMATE... 
EQUIPMENT...