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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KBOX 100310
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
1010 PM EST TUE FEB 9 2010

.SYNOPSIS...
A RAPIDLY INTENSIFYING COASTAL STORM WILL BRING SIGNIFICANT SNOW AND
STRONG WINDS TO PORTIONS OF SOUTHERN NEW ENGLAND...WITH AREAS ALONG
AND SOUTH OF THE MASS TURNPIKE MOST AT RISK FOR SUBSTANTIAL AMOUNTS.
HIGH PRESSURE THEN BRINGS DRY AND SEASONABLY COLD WEATHER THURSDAY
INTO THIS WEEKEND.  ANOTHER LOW PRESSURE MAY SWIFTLY PASS US
SOMETIME SUNDAY NIGHT INTO MONDAY NIGHT.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
-- Changed Discussion --
LOTS OF FORECAST UNCERTAINTY REMAIN THIS EVENING...MAINLY IN SNOWFALL
AMOUNTS FOR WEDNESDAY NORTH OF THE SOUTH COAST. WE ARE CERTAIN THAT
HEAVY BANDED SNOWFALL WILL DEVELOP JUST SOUTH OF NEW ENGLAND LATE
TONIGHT INTO EARLY TOMORROW MORNING WITH 1-2 INCH PER HOUR RATES.
WE ARE PRETTY CONFIDENT THAT THIS BAND WILL MOVE NORTHWARD AND AFFECT
THE AREA FROM HARTFORD TO PROVIDENCE TO PLYMOUTH WITH VERY HEAVY
SNOWFALL RATES DURING THE LATE MORNING AND AFTERNOON HOURS.

THE PROBLEM IS THAT WE DON/T KNOW FOR SURE HOW FAR NORTH THE INTENSE
SNOWFALL RATES WILL PROGRESS FROM THERE BEFORE PIVOTING THEN MOVING
EASTWARD AND SUBSEQUENTLY OUT TO SEA. WE DID SEE THE NEW NAM...WHICH
BASICALLY PITCHES A SHUTOUT ALONG AND NORTH OF THE MASS PIKE. WE ARE
CERTAIN THERE WILL BE A TIGHT SNOWFALL GRADIENT...BUT WE ARE NOT
QUITE SURE WHERE IT FINALLY END UP. IT/LL PROBABLY BE SOMEWHERE NEAR
THE MASS PIKE. WE WILL BE LOOKING AT THE FULL SUITE OF 00Z DATA AND
INCORPORATING SCIENCE AND CLIMO OVER THE NEXT FEW HOURS TRY TO PIN
THINGS DOWN A BIT BETTER. HOWEVER...AS OF RIGHT NOW...UNCERTAINTY IN
THE WATCH AREA IS TOO HIGH TO CONVERT TO WARNINGS OR ADVISORIES AT
THIS TIME.

FOR THE REST OF THE OVERNIGHT HOURS...WE ARE EXPECTING DRY CONDITIONS
WITH THICKENING CLOUDS.
-- End Changed Discussion --

&&

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

-- Changed Discussion --
PREVIOUS DISCUSSION FROM TUE AFTN...

LOOKING AT THE MODEL SUITE...APPEARS TO BE TWO CAMPS FOR THE
UPCOMING STORM BEGINNING AROUND MID MORNING WEDNESDAY AND CONTINUING
THROUGH AROUND MIDNIGHT WEDNESDAY NIGHT. SEEING THIS MORNINGS NAM
GAVE US PAUSE SEEING HOW IT PUSHED THE DEVELOPING LOW FURTHER N AND
PASSING IT CLOSE TO THE BENCHMARK WED NIGHT...ALONG WITH ITS BANDING
FEATURES. THE 12Z GFS AND UKMET WERE CLOSE TO THIS SOLUTION.
HOWEVER...THE TWO CANADIAN MODELS AS WELL AS THE ECMWF KEPT THE LOW
PASSING FURTHER S THAN THE OTHER MODELS AS WELL AS THEIR PACKAGES OF
QPF AND A SHARP NORTHERN EDGE.

ALREADY SEEING AREA OF C/G LIGHTNING OFF THE CAROLINA COAST AT
18Z...SO IT LOOKS LIKE THE LOW IS STARTING TO DEVELOP IN THAT
REGION. CONSIDERING THE SETUP OVER QUEBEC AND THE EXPLOSIVE
DEVELOPMENT THAT THIS LOW WILL UNDERGO OVER THE NEXT 24 HOURS AS
WELL AS THE EXCELLENT MOISTURE INFLOW...FELT THAT THE FURTHER N
SOLUTION WAS MORE PRUDENT...ESPECIALLY CONSIDERING THE BANDING
FEATURES THAT BOTH THE NAM AND GFS EXHIBITED. ONE DISCONCERTING
NOTE TO THESE MODELS WAS THE AMOUNT OF WARM AIR INTRUSION FROM THE
OCEAN...WHICH WOULD CUT BACK ON SNOW AMOUNTS ESPECIALLY AT THE
ONSET OF THE STORM ALONG THE COAST. IT DOES LOOK LIKE S COASTAL
AREAS AS WELL AS COASTAL PLYMOUTH COUNTY WILL START OFF WITH A MIX
OR EVEN ALL RAIN. HOWEVER...AS THE LOW DEEPENS AND WRAPS THE COLD
AIR BACK AROUND...SHOULD SEE A CHANGE TO HEAVY...WET SNOW ESPECIALLY
ON THE CAPE AND ISLANDS WED NIGHT.

APPEARS TO BE ENOUGH QPF AND BANDING TO GIVE MOST AREAS WARNING
CRITERIA SNOWFALL WITH THE HEAVIEST AMOUNTS ACROSS N CT/N RI INTO
INTERIOR SE MA. BASED ON OUR FORECAST THIS AFTERNOON...HAVE ISSUED A
WINTER STORM WARNING FROM NEAR THE MASS PIKE SOUTHWARD FOR WED TIL
AROUND MIDNIGHT OR SO WED NIGHT. WHILE WE FEEL THAT THE SNOW WILL
MAKE IT ALL THE WAY NORTHWARD TO ROUTE 2 AND INTO SOUTHERN NEW
HAMPSHIRE...THE QUESTION OF MAX QPF PLACEMENT AND LOW TRACK RAISED
BY THE ECMWF...GGEM AND RGEM...DECIDED TO HOLD OFF ON ISSUING THE
WARNING FOR THOSE AREAS TO SEE IF LATER MODEL RUNS HELP CLEAR UP
THIS ISSUE.

THE OTHER CONCERN IS THE WINDS PICKING UP ALONG THE COAST. MODELS
ARE STILL INDICATING A VERY STRONG LOW LEVEL JET...ON THE ORDER OF
50-55 KT AT 925 HPA...MOVING ACROSS S COASTAL AREAS LATE WED
AFTERNOON AND WED NIGHT. FELT THE BEST SHOT OF 55-60 MPH GUSTS WILL
OCCUR ON CAPE COD AND THE ISLANDS...SO ISSUED THE HIGH WIND WARNING
FOR THOSE AREAS. ALONG THE REMAINDER OF THE COAST...WILL LIKELY SEE
ADVISORY LEVEL WINDS BUT THIS IS COVERED UNDER THE WINTER STORM
WATCH/WARNING ALREADY ISSUED.

THE LAST QUESTION WILL BE WHETHER CONDITIONS COULD REACH BLIZZARD
CRITERIA. WE DISCUSSED THIS...AND FELT THAT DUE TO THE HEAVY NATURE
OF THE SNOW EVEN IN SOME OF THE LIKELY SNOW BANDS...IT WOULD BE
DIFFICULT FOR VSBYS TO LOWER BELOW 1/4 MILE SO WE DID NOT GO WITH
BLIZZARD WARNINGS. IT WILL BE CLOSE IN SOME AREAS MAINLY EARLY WED
NIGHT...BUT WILL PROBABLY NOT QUITE MAKE IT.

DAYTIME HIGHS WEDNESDAY WILL REACH THE MID TO UPPER 30S ALONG THE
COAST...BUT WILL START TO DROP BY AROUND MIDDAY AS COLDER AIR WRAPS
IN AROUND THE LOW. OVERNIGHT LOWS WILL FALL TO THE 20S TO AROUND 30
WITH SOME UPPER TEENS ACROSS THE E SLOPES OF THE BERKSHIRES.
-- End Changed Discussion --

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
THIS PORTION OF THE FORECAST STARTS OUT WITH THE DEPARTURE OF THE
NOREASTER THURSDAY.  CYCLONIC CURVATURE AND A LITTLE BIT OF COLD AIR
ADVECTION COULD RESULT IN SCATTERED OCEAN-EFFECT SNOW SHOWERS ACROSS
THE OUTER CAPE AND NANTUCKET.  THE PROBLEM WILL BE THE WINDS...
WHICH ARE LIKELY TO BE TOO STRONG TO ALLOW SUCH A SNOW BAND TO
DEVELOP.  WILL NEED TO MONITOR THIS...AS THE FORECAST IS MAINLY DRY
THURSDAY AFTERNOON INTO THURSDAY NIGHT.

WINDS DIMINISH AND BECOME MORE NORTHWEST THURSDAY NIGHT INTO
FRIDAY.  THIS SHOULD BE A RELATIVELY TRANQUIL PERIOD HEADING INTO
SUNDAY WITH BELOW NORMAL TEMPERATURES.

THE NEXT POTENTIAL SNOWFALL LOOKS TO BE SOMETIME SUNDAY NIGHT INTO
MONDAY NIGHT.  EXPECTING A QUICK-MOVER...WHICH WOULD LIMIT
ACCUMULATION POTENTIAL.  TIMING WITH THIS SYSTEM IS STILL VERY
UNCERTAIN.  09/12Z GFS SLIGHTLY LAGS THE ECMWF.  LEANED TOWARD THE
GFS FOR NOW WHICH WAS IN SLIGHTLY BETTER AGREEMENT WITH PREVIOUS
FORECAST.

&&

.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
TONIGHT...
VFR TO START WITH MVFR CIGS ENTERING BDL/BAF LATE. SNOW MAY
APPROACH BDL/BAF TOWARD 12Z. ELSEWHERE...SNOW SHOULD HOLD OFF TILL
AFTER 12Z.

WEDNESDAY...
MODERATE TO HIGH CONFIDENCE ON LIFR CONDITIONS 18Z-00Z FROM BDL-ORH-
BOS AND POINTS SOUTH IN HEAVY SNOW WITH VSBYS 1/2 MILE OR LESS...STRONG
EAST- NORTHEAST WINDS AND SNOWFALL RATES OF 1-2 INCHES POSSIBLE.
NORTH OF THIS LINE INCLUDING MHT HIGHER PROBABILITY OF MVFR POSSIBLY
LOWERING TO IFR IN SNOW. LIFR CONDITIONS MAY ENTER BDL/BAF AS EARLY
AS 15Z- 18Z. MODERATE TO HIGH CONFIDENCE FOR ISSUANCE OF AVIATION
WEATHER WARNINGS FOR STRONG WINDS AND LOW VSBYS RI AIRPORTS AS WELL
AS LOGAN WEDNESDAY AFTERNOON.

WEDNESDAY NIGHT...
HIGH CONFIDENCE IN IFR CONDITIONS IN SNOW ACROSS MOST TERMINALS...
BUT CONDITIONS ACROSS MHT ARE MORE UNCERTAIN. NORTHEAST WIND GUSTS
OF 35 TO 45 KNOTS ARE POSSIBLE ACROSS THE COASTAL TERMINALS...
POSSIBLY UP TO 50 KT OVER THE CAPE AND ISLANDS. AVIATION WEATHER
WARNINGS LIKELY TO CONTINUE OVERNIGHT.


OUTLOOK...THURSDAY THROUGH SUNDAY...

THURSDAY...EXPECT CONDITIONS TO IMPROVE TO VFR ACROSS MOST LOCATIONS
BY EARLY TO MID MORNING...WITH THE POSSIBLE EXCEPTION OF KHYA AND
KACK.

FRIDAY INTO SUNDAY...HIGH CONFIDENCE FOR VFR.

&&

.MARINE...
TONIGHT...W-NW WINDS MAINLY AT 10 KT OR LESS WILL SHIFT TO EASTERLY
LATE AT NIGHT AND BEGIN TO INCREASE ACROSS THE SOUTHERN OUTER
WATERS.

WEDNESDAY AND WEDNESDAY NIGHT...AS LOW PRES RAPIDLY DEVELOPS S OF
NEW ENGLAND AND PUSHES NEAR 40N LATITUDE...EXPECT E-NE WINDS TO
QUICKLY INCREASE TO GALE FORCE WED AFTERNOON...THEN SOME STORM FORCE
GUSTS ON THE OUTER WATERS MAINLY NEAR AND S OF CAPE COD AND THE S
COAST WHERE THE STRONG LOW LEVEL JET PASSES. HAVE ISSUED A STORM
WARNING FOR THOSE AREAS AND GALES ELSEWHERE.

USED THE SWAM NAM WAVE MODEL GUIDANCE AS SEAS WILL BUILD CLOSE TO 20
FT E OF CAPE COD AND NANTUCKET...MAY EVEN SEE THE SEAS BUILD TO OVER
10 FT ON THE UPPER PORTION OF CAPE COD BAY AS WINDS BACK TO N WED
NIGHT.

OUTLOOK...THURSDAY THROUGH SUNDAY...
NORTH TO NORTHWEST GALE FORCE WIND GUSTS SHOULD DIMINISH BY LATE
THURSDAY MORNING OR AFTERNOON...BUT SMALL CRAFT ADVISORY WINDS
CONTINUE.  WINDS CONTINUE TO DIMINISH THURSDAY NIGHT INTO FRIDAY...
BUT ROUGH SEAS ARE LIKELY TO CONTINUE ACROSS THE OUTER COASTAL
WATERS INTO SATURDAY.  THERE IS THE POSSIBILITY OF ROUGH SEAS AND
WIND GUSTS UP TO 25-30 KT SATURDAY NIGHT INTO SUNDAY.

&&

.TIDES/COASTAL FLOODING...
TIDES WILL PEAK AT 2-2.5 FT ABOVE NORMAL ACROSS THE EASTERN MA COAST
WED NIGHT INTO THU MORNING WITH 20+ FT SEAS DEVELOPING JUST OFFSHORE
BY LATE WED NIGHT. NO PROBLEMS ARE ANTICIPATED DURING THE WED EVENING
HIGH TIDE AS THIS IS A LOW ASTRO TIDE AND SEAS WILL JUST BE IN THE
PROCESS OF RAMPING UP. THE THU MORNING HIGH TIDE IS HIGHER AND
ALTHOUGH WINDS WILL BE SHIFTING TO THE N/NW...A STORM SURGE OF 2 FEET
AND 15-20 FT SEAS COULD RESULT IN SOME MINOR COASTAL FLOODING AS A
WORST CASE SCENARIO...PARTICULARLY FROM THE OUTER CAPE TO ACK WHERE
THE HIGHEST SEAS WILL BE.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
CT...WINTER STORM WARNING FROM 8 AM WEDNESDAY TO 1 AM EST THURSDAY
     FOR CTZ002>004.
MA...WINTER STORM WATCH FROM 8 AM EST WEDNESDAY THROUGH LATE
     WEDNESDAY NIGHT FOR MAZ002>008-010-014-026.
     WINTER STORM WARNING FROM 8 AM WEDNESDAY TO 1 AM EST THURSDAY
     FOR MAZ009-011>013-015>024.
     HIGH WIND WARNING FROM 4 PM WEDNESDAY TO 7 AM EST THURSDAY FOR
     MAZ022>024.
NH...WINTER STORM WATCH FROM 8 AM EST WEDNESDAY THROUGH LATE
     WEDNESDAY NIGHT FOR NHZ011-012-015.
RI...WINTER STORM WARNING FROM 8 AM WEDNESDAY TO 1 AM EST THURSDAY
     FOR RIZ001>008.
MARINE...STORM WARNING FROM 4 PM WEDNESDAY TO 5 AM EST THURSDAY FOR
     ANZ231-232-250-254>256.
     GALE WARNING FROM 1 PM WEDNESDAY TO 5 AM EST THURSDAY FOR
     ANZ230-233>237-251.
-- End Changed Discussion --

&&

$$
SYNOPSIS...BELK
NEAR TERM...EKSTER
SHORT TERM...EVT
LONG TERM...BELK
AVIATION...BELK/EKSTER/EVT
MARINE...BELK/EKSTER/EVT
TIDES/COASTAL FLOODING...