FXUS61 KBOX 270022
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
722 PM EST THU NOV 26 2009

.SYNOPSIS...
WEAK HIGH PRESSURE WILL REMAIN ACROSS NEW ENGLAND THIS EVENING AS LOW
PRESSURE DEVELOPS OFF THE CAROLINAS. THIS STORM WILL RAPIDLY
INTENSIFY INTO A GALE CENTER AS IT TRACKS EAST OF NEW ENGLAND FRIDAY
AND THEN INTO THE MARITIMES FRIDAY NIGHT AND SATURDAY...BRINGING STRONG
NORTHWEST WINDS AND COOLER TEMPERATURES. HIGH PRESSURE WILL BRING
DIMINISHING WINDS AND MILDER CONDITIONS SUNDAY. MILD WEATHER
CONTINUES MONDAY AND MONDAY NIGHT AS A SHOWERY COLD FRONT MOVES
ACROSS THE AREA...FOLLOWED BY COOLER AND DRIER WEATHER TUESDAY AND
WEDNESDAY.

&&

.NEAR TERM /UNTIL MIDNIGHT TONIGHT/...
THE MAJORITY OF THE INTERIOR IS EXPECTED TO REMAIN DRY THIS EVENING
WHILE WEAK SURFACE RIDGING LINGERS IN THE REGION. HOWEVER 00Z RADAR
IMAGERY DOES INDICATE SHOWERS DEVELOPING SOUTH OF NANTUCKET AND THE
VINEYARD WELL AHEAD OF AN APPROACHING LOW PRESSURE SYSTEM. THESE
SHOWERS WILL CROSS PRIMARILY OVER THE CAPE AND THE ISLANDS THIS
EVENING...THOUGH A FEW MAY MAKE IT FURTHER N AND W.

ABOVE NORMAL TEMPS WILL CONTINUE WITH DEW PTS IN THE 40S AND CLOUD
COVER PRECLUDING TEMPS FROM FALLING MUCH AFTER SUNSET.

&&

.SHORT TERM /MIDNIGHT TONIGHT THROUGH FRIDAY NIGHT/...
OVERNIGHT AND FRIDAY...
WELL THE LATEST WATER VAPOR IMAGERY IS VERY TELLING WITH IMPRESSIVE
LONG WAVE TROF EVOLVING ACROSS THE GREAT LAKES AND UPPER MS VLY AS
SEVERAL POTENT SHORT WAVES/JET STREAKS ROTATE THROUGH THE MEAN TROF.
THIS WILL INDUCE SIGNIFICANT CYCLOGENESIS TOWARD MORNING SOMEWHERE
FROM NANTUCKET TO WESTERN GEORGES BANK. MODELS DIFFER ON HOW RAPIDLY
CYCLOGENESIS WILL OCCUR. THE GFS IS MOST ROBUST WITH A 989 MB LOW
JUST EAST OF NANTUCKET 12Z FRI. THE 12Z NAM IS A SLOW OUTLIER WITH
THE 12Z UKMET AND 12Z ECMWF CLOSER TO THE GFS ALTHOUGH NOT AS STRONG. 

AFTER COLLABORATING WITH HPC WE FAVOR THE STRONGER GFS GIVEN AMPLITUDE
OF TROF ALREADY SEEN ON WATER VAPOR IMAGERY ALONG WITH EARLY SEASON
OCEAN WARMTH. THIS WILL SUPPORT STRONGER AND FASTER SURFACE DEVELOPMENT AS
STRONG HEIGHT FALLS/COOLING TEMPS ALOFT DECREASE STATIC STABILITY
OVER THE RELATIVELY WARM OCEAN.

THUS THIS FORECAST WAS BASED ON THE 12Z GFS AND ITS MOS OUTPUT. MAIN
HAZARD WITH THIS STORM WILL BE STRONG WINDS. AS SURFACE LOW BEGINS TO
BOMB/INTENSIFY FRI MORNING OVER WESTERN GEORGES BANK A PERIOD OF
STRONG EAST/NORTHEAST ARE POSSIBLE ACROSS THE CAPE AND ISLANDS. THEN
AS SURFACE LOW BEGINS TO LIFT NORTH INTO THE GULF OF ME STRONG LOW
LEVEL WEST/NORTHWEST JET DEVELOPS WITH 925 MB WINDS INCREASING TO
ABOUT 50 KT. THIS COMBINED WITH STRONG PRES RISE/FALL COUPLET WIND
GUSTS TO 40 TO 50 MPH LIKELY ACROSS CAPE COD AND THE ISLANDS DURING
THE AFTERNOON. THEREFORE A WIND ADVISORY HAS BEEN POSTED FOR THIS
AREA. 

EXPECT A PERIOD OF HEAVY RAINFALL FRIDAY AS STRONG JET DYNAMICS
OVERSPREAD THE REGION. LFQ OF 120 KT JET APPROACHES FROM THE SOUTH
FRI MORNING...WITH LOTS OF CURVATURE/DIVERGENCE ALOFT ACROSS THE
REGION. THIS WILL SUPPORT HEAVY RAINFALL. IN ADDITION...THUNDER
/ELEVATED CONVECTION/ POSSIBLE AS WELL ACROSS EASTERN CT/RI AND
SOUTHEAST AS MID LEVEL LAPSE RATES STEEPEN WITH DRY SLOT MOVING ACROSS
THE CAPE AND ISLANDS. THIS DEEP LAYER DRY AIR WILL LIKELY RESULT IN
LESS QPF ACROSS THIS AREA.

FRI NIGHT...
MID LEVEL LOW AND SURFACE CIRCULATION LIFT NORTHEAST OF THE AREA FRI
NIGHT. HOWEVER LOTS OF WARM AIR ALOFT WRAPPING CYCLONICALLY AROUND THE
MID LEVEL LOW ACROSS OUR REGION. THIS WILL YIELD LIGHTER COMMA
HEAD/TROWAL PRECIP ACROSS THE REGION. THERMAL PROFILES/SOUNDINGS ARE
MARGINALLY COLD ENOUGH TO SUPPORT SNOW ACROSS THE INTERIOR WITH
FREEZING LEVELS DOWN TO 2-3KFT. HOWEVER LIFT APPEARS WEAK SO PRECIP
INTENSITY MAY NOT BE SUFFICIENT FOR RAIN TO COMPLETELY TURN OVER TO
ALL SNOW. MOST LIKELY SCENARIO APPEARS TO BE A MIX OF RAIN AND SNOW
OVER THE HIGHER TERRAIN WITH LITTLE IF ANY ACCUMULATION. ELSEWHERE
PERIODS OF COLD RAIN. 

WINDY CONDITIONS WITH STRONG WEST/NORTHWEST LOW LEVEL JET ACROSS THE
REGION. ALTHOUGH MODEL SOUNDINGS SUGGEST WINDS BELOW WIND ADVISORY
CRITERIA AS LOW LAPSE RATES REMAIN UNFAVORABLE FOR WIND TRANSFER. THE
EXCEPTION MAY BE ACROSS THE HIGHEST ELEVATIONS INCLUDING CAPE COD AND
THE ISLANDS.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
MODELS IN AGREEMENT OF DEEP COASTAL LOW CENTER REACHING MAINE/NOVA 
SCOTIA FOR 12Z SAT.  WRAP AROUND MOISTURE COULD BRING SOME LINGERING 
LIGHT RAIN TO THE CAPE AND VICINITY EARLY IN THE DAY. OTHERWISE 
LOOKS LIKE DIMINISHING CLOUDS...BUT THE DAY WILL BE PUNCTUATED BY 
GUSTY WINDS. GFS STARTS OFF 12Z SAT WITH 55 TO 60 KTS AT H850 OVER 
SOUTHERN NEW ENGLAND...DIMINISHING GRADUALLY OVER THE COURSE OF THE 
DAY. THE COLDER AIR SPILLING IN BEHIND THE LOW DURING THE DAY ENHANCES
THE POTENTIAL FOR MIXING OF THESE WINDS. 

COULD SEE WIND ADVISORY CONDITIONS OVER MUCH OF THE AREA. STILL 4
PERIODS OUT SO WILL CONTINUE MENTION OF POTENTIAL FOR ADVISORY
CRITERIA IN HWO...MAINLY FOR THE CAPE AND ISLANDS AND SOUTH COAST BUT
POTENTIALLY INLAND AS WELL.

WINDS DIMINISH SAT NIGHT AS HIGH PRESSURE MOVES INTO THE AREA.  DRY 
WEATHER CONTINUES FOR SUN BUT COULD SEE SOME INCREASE IN CLOUDS AS 
WEAK LOW MOVES OUT OF THE GREAT LAKES REGION. ECMWF ABOUT 12 
HOURS SLOWER THAN GFS ON PASSAGE OF ASSOCIATED COLD FRONT...BUT 
GENERALLY FRONT SHOULD TRACK THROUGH SOUTHERN NEW ENGLAND LATE MON 
AND MON NIGHT. SUN NIGHT SOME LIGHT QPF COULD FALL AHEAD OF THE 
FRONT...PRECIP TYPE MAY BE LIGHT RAIN/SNOW MIX IN THE FAR INTERIOR. THEN
MON NIGHT BEHIND LOW PRESSURE/FRONT...THICKNESSES/FORECAST SOUNDINGS
COLD ENOUGHT FOR A CHANCE OF SNOW SHOWERS IN FAR INTERIOR.

TUE AND WED DRY WEATHER ANTICIPATED WHILE HIGH PRESSURE CROSSES
THROUGH THE AREA. MODELS INDICATE ANOTHER LOW PRESSURE SYSTEM
IMPACTING THE AREA IN THE WED NIGHT TO THU TIMEFRAME...WILL CONTINUE
CHANCE POPS.

&&

.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
TONIGHT...CONDITIONS LOWER TO IFR-LIFR AS RAIN PUSHES IN FROM THE S.
WINDS START TO INCREASE AFTER 06Z AS DIRECTION BACKS TO N WITH THE
QUICKLY DEEPENING LOW PRES.

FRIDAY...WIDESPREAD IFR CIGS/VSBYS IN RAIN AND FOG. CONDITIONS 
SLOWLY IMPROVE TO MVFR BDL/BAF DURING THE AFTERNOON. W-NW WIND GUSTS
UP TO 40 KT LATE MORNING THROUGH THE AFTERNOON HYA/FMH/ACK...GUSTS TO
30 KTS POSSIBLE BOS.

OUTLOOK /FRIDAY NIGHT THROUGH TUESDAY/...

FRIDAY NIGHT AND SATURDAY...MVFR CONDITIONS LINGER FRI NIGHT WITH
AREAS OF IFR IN LIGHT RAIN AND FOG. BUT CONDITIONS IMPROVE TO VFR SAT
MORNING. STRONG SURFACE WINDS SAT WITH W WIND GUSTS 35-40 KT AND
ASSOCIATED MECHANICAL TURBULENCE. WINDS DIMINISH LATE
SATURDAY/SATURDAY NIGHT.

SUNDAY...VFR.

SUNDAY NIGHT AND MONDAY...CIGS LOWERING TO MVFR IN ADVANCE OF A COLD
FRONT...AREAS OF MVFR VSBYS IN SHOWERS. 

MONDAY NIGHT...MVFR CIGS WITH SCATTERED MVFR VSBYS IN RAIN
SHOWERS...POSSIBLE SNOW SHOWERS FAR INTERIOR.

TUESDAY...VFR.

&&

.MARINE...
TONIGHT...
TRANQUIL THIS EVENING THEN EAST/NORTHEAST WINDS INCREASE TOWARD
DAYBREAK AS LOW PRES DEVELOPS SOUTH OF NEW ENGLAND. EAST/NORTHEAST
WINDS WILL INCREASE TO 20-25 KT LATE ACROSS NANTUCKET WATERS TOWARD
DAYBREAK.

FRI...
LOW PRES INTENSIFIES INTO A GALE CENTER AS IT TRACKS ACROSS WESTERN
GEORGES BANK EARLY FRI THEN INTO THE GULF OF ME. A BRIEF PERIOD OF
EAST/NORTHEAST GALES LIKELY FRI MORNING ACROSS THE EASTERN MA WATERS
FOLLOWED BY WEST/NORTHWEST GALES IN THE AFTERNOON.

WEST/NORTHWEST GALES LIKELY ALL WATERS.

OUTLOOK /FRIDAY NIGHT THROUGH TUESDAY/...

FRI NIGHT AND SAT...POTENTIAL FOR A PROLONGED PERIOD OF GALE FORCE
WINDS DURING THIS TIMEFRAME AS LOW PRES CONTINUES TO TRACK TO THE NE.
THERE IS A LOW PROBABILITY OF STORM FORCE WINDS LATE FRI NIGHT INTO
SAT.

WINDS DIMINISH SATURDAY NIGHT INTO SUNDAY...BUT COULD STILL HAVE
GUSTS TO 25 KTS ON OUTER WATERS INTO SUNDAY NIGHT. SEAS SHOULD
REMAIN ROUGH ACROSS THE OUTER WATERS INTO SUNDAY NIGHT.

MON BRINGS INCREASING SEAS AND SW WINDS TO SCA RANGE AHEAD OF AN
APPROACHING COLD FRONT. POTENTIAL FOR SCA GUSTS ACROSS PORTIONS OF
THE WATERS MON NIGHT AND TUE BEHIND THE FRONT IN NW FLOW.

&&

.CLIMATE...
IT IS INTERESTING TO NOTE THAT BOSTON/S LOGAN AIRPORT HAS NOT FALLEN 
TO THE FREEZING MARK SO FAR THIS SEASON. THE LATEST IN THE SEASON 
THAT BOSTON HAS GONE WITHOUT HITTING 32F WAS DEC 2ND 1975. IT IS 
POSSIBLE WE BREAK THAT RECORD...BUT IT WILL BE CLOSE SUNDAY NIGHT... 
AND NOT COMPLETELY OUT OF THE QUESTION SATURDAY NIGHT...BUT A LOWER 
PROBABILITY THEN.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...WIND ADVISORY FROM 11 AM TO 5 PM EST FRIDAY FOR MAZ022>024.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 1 AM TO 10 AM EST FRIDAY FOR 
     ANZ231>234-255.
     GALE WARNING FROM 10 AM FRIDAY TO 6 AM EST SATURDAY FOR 
     ANZ230>234-250-251-254-255.
     GALE WATCH FROM FRIDAY EVENING THROUGH SATURDAY EVENING FOR 
     ANZ235>237-256.
     SMALL CRAFT ADVISORY FROM 10 AM TO 10 PM EST FRIDAY FOR 
     ANZ235>237-256.
     SMALL CRAFT ADVISORY UNTIL 10 AM EST FRIDAY FOR ANZ250-251-254.

&&

$$
SYNOPSIS...NOCERA
NEAR TERM...NOCERA/NMB
SHORT TERM...NOCERA
LONG TERM...NMB
AVIATION...EVT/NMB
MARINE...NOCERA/NMB
CLIMATE...