FXUS61 KBOX 040859
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
358 AM EST FRI DEC 4 2009
.SYNOPSIS...
HIGH PRESSURE WILL PREVAIL ACROSS THE REGION THROUGH FRIDAY NIGHT.
LOW PRESSURE WILL DEVELOP OFF THE SOUTHEAST U.S. COAST TONIGHT AND
MOVE TO THE SOUTHEAST OF NANTUCKET SATURDAY EVENING. HIGH PRESSURE
WILL FOLLOW SUNDAY AND MONDAY...BEFORE ANOTHER POTENTIALLY STRONG
LOW PRESSURE SYSTEM AFFECTS SOUTHERN NEW ENGLAND MIDWEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
QUIET WEATHER DAY ON TAP FOR TODAY AS WE WILL BE IN BETWEEN TWO STORM
SYSTEMS IN THIS PROGRESSIVE PATTERN. WEAK SURFACE HIGH PRESSURE
RIDGING WILL BE OVERHEAD TODAY...AND THIS SHOULD PROVIDE US WITH
MOSTLY SUNNY SKIES. THE AIR MASS IN THE WAKE OF YESTERDAY/S STRONG
STORM SYSTEM IS NOT ALL THAT COLD. THEREFORE...WE ARE FORECASTING
HIGHS AROUND 10 DEGREES ABOVE NORMAL TODAY. WINDS SHOULD BE PRETTY
LIGHT. A STUBBORN PATCH OF BROKEN STRATOCU FROM ORH NWWD TO SWRN NH
AND NW MASS SHOULD GRADUALLY THIN OUT EARLY THIS MORNING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
MAIN FORECAST CONCERNS IN THE SHORT TERM PERIOD REVOLVE AROUND THE
POTENTIAL EFFECTS FROM COASTAL LOW PRESSURE THAT IS FORECAST TO MOVE
SOUTHEAST OF NANTUCKET SATURDAY EVENING. THE FORECAST MODELS HAVE
BEEN HAVING A TOUGH TIME WITH THIS SYSTEM OVER THE LAST COUPLE OF
DAYS...AND SEVERAL INCONSISTENCIES STILL EXIST. THE MAIN TROUBLE IS
IN PROJECTING THE STRENGTH AND AMPLITUDE OF THE SHORT WAVE EJECTING
OUT OF DEEP SOUTH TEXAS TODAY AND IT/S EVENTUAL INTERACTION WITH THE
NORTHERN STREAM IN 24 TO 36 HOURS. OVERALL...THE TREND IN THE 00Z
MODEL SUITE HAS BEEN SLIGHTLY WESTWARD ON THE EAST COAST...ESPECIALLY
THE ECMWF. WE THINK THE NAM COULD BE OVERDONE WITH A LITTLE TOO
AMPLIFIED OF A SOLUTION HOWEVER.
THE UPSHOT IS THAT WE FEEL A 03Z SREF/00Z ECMWF/UKMET/NAM BLEND WAS
BEST. THE GFS SEEMS LIKE TOO MUCH OF AN EASTERLY OUTLIER AT THIS
TIME. ADDITIONAL MODEL ADJUSTMENTS ARE STILL LIKELY OVER THE NEXT 24
HOURS AND WILL LIKELY HAVE AN IMPACT ON THE FORECAST. THEREFORE...WE
EXPECT CLOUDS TO GRADUALLY INCREASE TONIGHT AS MID AND HIGH LEVEL
MOISTURE STREAMS NORTHEASTWARD FROM THE GULF STATES. IT WILL REMAIN
DRY HOWEVER.
LIGHT PRECIPITATION SHOULD BEGIN OVERSPREADING MUCH OF THE CWA FROM
SOUTH TO NORTH DURING THE DAY SATURDAY. AS FAR AS POPS GO...WE ARE
GOING WITH LIKELY IN THE CENTRAL AND WESTERN ZONES BY
AFTERNOON...WITH CHANCE FAR NORTHWEST. ON THE COASTAL PLAIN...HIGH
LIKELY TO LOW END CATEGORICAL SEEMS PRUDENT. THE LOW LEVEL AIR MASS IN
PLACE WILL BE RELATIVELY WARM...SO MOST OF THE PRECIPITATION THAT
FALLS SATURDAY SHOULD BE IN THE FORM OF RAIN. HOWEVER...HIGHER
ELEVATIONS WILL PROBABLY START MIXING WITH THEN CHANGE TO LIGHT SNOW
BY LATER IN THE DAY WITH MINOR ACCUMS POSSIBLE AS THE PRECIP BECOMES
A BIT HEAVIER AND COOLER BOUNDARY LAYER AIR BLEEDS DOWN FROM THE
NORTH.
THE COLUMN WILL CONTINUE TO COOL OFF SATURDAY EVENING...AND AS LONG
AS STEADY PRECIPITATION IS FALLING...WE SHOULD GRADUALLY CHANGE TO
SNOW FROM WEST TO EAST. DEPENDING ON THE INTENSITY OF THE
PRECIPITATION...WHICH IS IN QUESTION RIGHT NOW...A LIGHT ACCUMULATING
SNOWFALL MAY OCCUR EVEN ON THE COASTAL PLAIN. LOW CONFIDENCE EXISTS
AT THIS TIME ON ANY EXACT SNOWFALL AMOUNTS BECAUSE THE TRACK OF THE
STORM IS STILL SOMEWHAT UNCERTAIN. HOWEVER...WOULDN/T BE SURPRISED TO
SEE A GENERAL 1 TO 3 INCH SNOWFALL AT HIGHER ELEVATIONS AND UP TO AN
INCH OR TWO ON THE COASTAL PLAIN WITH SOME UPSIDE POTENTIAL. A STORM
TRACK THAT RESULTS IN HEAVIER PRECIPITATION AND MORE DYNAMIC COOLING
/PERHAPS FROM THE DEVELOPMENT OF SOMEWHAT ORGANIZED BANDING/ WOULD
RESULT IN HIGHER SNOWFALL AMOUNTS...AND THE ISSUANCE OF AT LEAST
ADVISORIES...ESPECIALLY IF THE STORM SLOWS A BIT AND ALLOWS MORE
PRECIPITATION TO FALL AFTER DARK. STAY TUNED.
THE PRECIPITATION IS EXPECTED TO TAPER OFF AND GRADUALLY END FROM
WEST TO EAST AFTER MIDNIGHT SATURDAY NIGHT.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
HIGH PRESSURE WILL BUILD INTO REGION SUN AND MON BEFORE HEADING
OFFSHORE MON NIGHT. THIS WILL ALLOW WEAK LOW TO PASS TO OUR N MON
NIGHT AND TUE MORNING...BUT DYNAMICS AND MOISTURE APPEAR TO BE
LACKING. KEPT CHANCE POPS ALONG AND NORTH OF MASS PIKE WHERE DEEPER
MOISTURE EXISTS. THERMAL PROFILES SUGGEST POSSIBILITY OF LIGHT SNOW
ACROSS SW NH AND NORTHERN MA...BUT NO MORE THAN A DUSTING APPEARS
LIKELY.
CONFIDENCE IS STARTING TO INCREASE ON ANOTHER RAIN/WIND EVENT IN
WED/THU TIME FRAME AS YET ANOTHER SOUTHERN STREAM SYSTEM IS FORECAST
TO LIFT INTO GREAT LAKES. GFS AND ECMWF SOLUTIONS ARE NOT TOO FAR OFF
FROM ONE ANOTHER AND MATCH UP WELL WITH GEFS. ALTHOUGH IT IS
CERTAINLY A BIT EARLY TO LINE UP DETAILS...POTENTIAL EXISTS FOR
STRONG WINDS AS MODELS SHOW DECENT LOW LEVEL JET /60-70KT AT 925MB/
HEADING UP COAST. ALSO APPEARS TO BE A GOOD SLUG OF RAINFALL AS
SOUTHERLY WINDS ALOFT TRANSPORT GULF MOISTURE NORTHWARD. MAY BE
LOOKING AT SIMILAR SITUATION TO YESTERDAY WHERE WE SEE A 6-8 HR
PERIOD OF HEAVY RAINFALL...WHICH CUTS OFF SHARPLY AS WARM FRONT LIFTS
THROUGH REGION.
TEMPERATURES SHOULD WARM SLOWLY EARLY WED PRIOR TO ONSET OF
PRECIPITATION...BUT IT MAY BE COLD ENOUGH TO ALLOW FOR SNOW AT START...
ESPECIALLY N AND W OF PVD/BOS CORRIDOR. HOWEVER PATTERN FAVORS QUICK
CHANGE TO RAIN IN ALL LOCATIONS BY WED AFTERNOON.
STRONG W/NW WINDS POSSIBLE BEHIND SYSTEM AS IT HEADS INTO CANADA
LATER THU. APPEARS THAT A SHOT OF COLDER AIR WILL ARRIVE IN SOUTHERN
NEW ENGLAND BY END OF NEXT WEEK.
&&
.AVIATION /09Z FRIDAY THROUGH WEDNESDAY/...
TODAY AND TONIGHT...VFR CONDITIONS WITH RELATIVELY LIGHT WINDS.
SATURDAY THROUGH SATURDAY NIGHT...MVFR TO IFR CONDITIONS POSSIBLE IN
RAIN AS COASTAL LOW PRESSURE APPROACHES THE WATERS TO THE SOUTHEAST
OF NANTUCKET. RAIN WOULD GRADUALLY TRANSITION TO SNOW LATE SATURDAY
AFTERNOON IN THE WEST AND DURING THE EVENING IN THE EAST WITH
POSSIBLE ASSOCIATED LOWER VSBYS. HOWEVER...CONFIDENCE IS NOT ALL THAT
HIGH WITH THE SYSTEM YET...THEREFORE CHANGES IN THINKING WILL BE
POSSIBLE.
OUTLOOK /SUNDAY THROUGH WEDNESDAY/...
SUN...MVFR CIGS POSSIBLE EARLY...THEN VFR.
MON...VFR.
TUE...MVFR POSSIBLE EARLY IN SCTD -SHRA/-SHSN...THEN VFR.
WED...POSSIBLE IFR AND STRONG WINDS.
&&
.MARINE...
TODAY...LINGERING SCA WINDS AND SEAS WILL GRADUALLY SUBSIDE
TODAY...WITH THE SEAS SLOWER TO DO SO.
TONIGHT...SCA SEAS WILL PROBABLY PERSIST ON THE SOUTHERN OUTER WATERS
THROUGH AT LEAST MIDNIGHT.
SATURDAY AND SATURDAY NIGHT...LOW PRESSURE WILL MOVE UP THE EAST
COAST SATURDAY AND PASS TO THE SOUTHEAST OF NANTUCKET SATURDAY
EVENING. NORTHERLY WINDS WILL INCREASE TO SCA LEVELS FROM SOUTH TO
NORTH SATURDAY...THEN GO NW BEHIND THE LOW SATURDAY NIGHT. THERE IS
SOME POTENTIAL FOR GALES DEPENDING ON THE STRENGTH AND TRACK OF THE
LOW.
OUTLOOK /SUNDAY THROUGH WEDNESDAY/...
SCA CONDITIONS PROBABLE SUN AS N/NW WINDS GRADUALLY DIMINISH AND SEAS
SUBSIDE. LIGHTER WINDS AND FLAT SEAS EXPECTED MON AS HIGH PRESSURE
BUILDS OVER NEW ENGLAND. COLD FRONT CROSSING WATERS TUE SHOULD BRING
SCA CONDITIONS BY AFTERNOON.
BEYOND USUAL 5-DAY OUTLOOK PERIOD...THERE IS POTENTIAL FOR GALE FORCE
WINDS WED INTO THU AS LOW PRESSURE TRACKS FROM SOUTHERN PLAINS TO
GREAT LAKES.
&&
.CLIMATE...
BOSTON/S LOGAN AIRPORT HAS NOT FALLEN TO THE FREEZING MARK SO FAR
THIS SEASON. THE RECORD LATEST IN THE SEASON THAT BOSTON HAS
RECORDED ITS FIRST 32F WAS DEC 2ND 1975. AS OF TODAY...THIS RECORD
HAS BEEN BROKEN. AVERAGE FIRST DATE OF 32 IN BOSTON IS AROUND
NOVEMBER 4TH. CURRENT FORECAST SUGGESTS THAT THE MINIMUM AT LOGAN
MAY NOT FALL TO BELOW FREEZING UNTIL SUNDAY NIGHT/EARLY MONDAY
MORNING.
AFTER YESTERDAY/S RECORD BREAKING HIGH TEMPERATURES...RECORD HIGH
MINIMUMS ARE IN JEOPARDY AT BOS...PVD...AND BDL THIS MORNING.
BOS... 48 IN 1932
PVD... 46 IN 1998 AND IN PREVIOUS YEARS
BDL... 43 IN 1932
ORH... 47 IN 1998
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EST THIS MORNING FOR
ANZ232>234-251.
SMALL CRAFT ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR ANZ235-
237-250-254>256.
&&
$$
SYNOPSIS...EKSTER
NEAR TERM...EKSTER
SHORT TERM...EKSTER
LONG TERM...JWD
AVIATION...EKSTER/JWD
MARINE...EKSTER/JWD
