FXUS61 KBOX 300909
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
409 AM EST MON NOV 30 2009
.SYNOPSIS...
LOW PRESSURE OVER WESTERN NEW YORK STATE WILL ADVANCE EASTWARD OVERNIGHT.
A STRONG COLD FRONT WILL SWEEP ACROSS SOUTHERN NEW ENGLAND MONDAY
AFTERNOON BRINGING A PERIOD OF RAIN SHOWERS...FOLLOWED BY DRY BRISK
WEATHER ON TUESDAY. THERE IS THE POTENTIAL FOR A STRONG STORM SYSTEM
BRINGING WIND DRIVEN RAIN LATE WEDNESDAY NIGHT INTO THURSDAY...
FOLLOWED BY SEASONABLY CHILLY AND MAINLY DRY WEATHER FRIDAY THROUGH
NEXT SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATE... NOT MUCH CHANGE TO FORECAST. JUST A FEW TEMPERATURE
ADJUSTMENTS...COOLER IN SOUTHERN NEW HAMPSHIRE BY A FEW DEGREES AND
WARMER BY A FEW DEGREES IN THE HARTFORD AREA BASED ON CURRENT
OBSERVATIONS. CLOUD COVER SHOULD HOLD TEMPERATURES NEARLY STEADY
OVERNIGHT. POPS STILL LOOK GOOD.
PREVIOUS DISCUSSION...
NEXT FAST MOVING SHORTWAVE MOVES EAST FROM THE GT LAKES
TONIGHT AND TRACKS ACROSS NORTHERN NEW ENGLAND MONDAY. ASSOCD
"STRENGTHENING" COLD FRONT MOVES WEST TO EAST ACROSS SNE MON
AFTERNOON AND EARLY EVENING.
BULK OF SHOWERS WILL OVERSPREAD SNE DURING MONDAY...MAY BEGIN NW
FRINGE OF THE FA AFTER 09Z MONDAY. 15Z SREF POPS USED AND IN AGREEMENT
WITH MANY 12Z OP MODELS ON VIRTUALLY NIL PRIOR TO 10Z IN OUR CWA.
CONFIDENCE HIGH ON THE FCST DETAILS TONIGHT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
RI AND SE MASS...MOST OF THE SHOWERS MAY HOLD OFF TIL MON AFTN. DUE
TO THE INCREASING FGEN...LIGHT TO MDT SHOWERS SHOULD BECOME MORE
WDSPRD AS THE FRONT CROSSES SNE...ESP SE 2/3RDS OF THE AREA. WE DO
SEE 12Z/29 RGEM AND GGEM AND 18Z NAM AS MORE CONSERVATIVE ON QPF BUT
ATTM .. SIDED WITH THE WETTER VERSIONS OF THE 12Z GFS/NAM UKMET AND
ECMWF.
THEREFORE...15Z SREF POPS RAISED 10 PCT DURING THE MIDDAY HOURS MONDAY
ALONG AND S OF THE MASS PIKE. MILD PRIOR TO THE SHOWERS INTO THE
FORENOON AND MIDDAY HOURS BDL ORH BOS SEWD WITH EVEN A LITTLE MORNING SUN?
THEN COOLING DURING THE AFTN IN SHOWERS.
CONFIDENCE ON THE DETERMINISTIC DETAILS MONDAY IS AVG.
MON NIGHT...SHOWERS ENDING SE NEW ENGLAND EVENING PER 15Z/29 SREF
POPS AND MULTI 12Z/29 OP MODEL AGREEMENT AS STRENGTHENING CFP MOVES
OFFSHORE AND GUSTY NW WINDS DEVELOP. MODELS WITH A NOTABLE INTENSIFYING
500 MB VORT-HFC /200M 12 HR/ CROSSING THE NJ COAST AT NIGHT SUGGESTING
AS PER PREV MODEL CYCLES THERE MAY BE SOME LAGGING OF THE SHOWER
DEPARTURE SE MASS AND HAVE RAISED OUR GUIDANCE A BIT IN THAT AREA.
THIS IDEA IS NOT IN AGREEMENT WITH THE 12Z EC...THEREFORE UNCERTAINTY
EXISTS REGARDING TIMING THE END OF THE SEVERAL HOUR WIDE SHOWER BAND.
NO SNOW FCST AT THE TAIL END DUE TO MILD BL TEMPS.
A DECENT SHOT OF CAA LATE MON NIGHT AND WHILE WE ARE NOT YET FCSTG
32F TUE MORNING DEC 1 IN BOS...IT MIGHT NUDGE FREEZING AT LOGAN PER
SEVERAL MODELS T1 TEMPS INCLUDING 18Z NAM.
AS OF THIS FCST...THE 12Z/29 NAM/GFS MOS WAS BLENDED FOR TT/TD/WIND
21Z TDY THRU 12Z TUE. SKY WAS AN APPROX 12Z/29 RGEM GFS/NAM 30/40/30
BLEND. GUSTS DRIVEN SOLELY FROM THE 12Z/29 NAM MXG HTS AND GUSTS
ALG. WE NOTE THE GUSTS ARE CAPPED ARD 26 KTS PARTS OF SE MASS MON
AFTN.
CONFIDENCE ON THE MON NIGHT DETERMINISTIC DETAILS IS AVG.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
TUESDAY NIGHT INTO WEDNESDAY...WEAK HIGH PRESSURE WILL TEMPORARILY
BUILD INTO THE REGION. LIGHT WINDS AND MAINLY CLEAR SKIES WILL
ALLOW OVERNIGHT LOWS TO FALL INTO THE MID 20S INTERIOR TO MID 30S ON
THE COAST. HIGHS ON WEDNESDAY SHOULD RECOVER INTO THE MID TO UPPER
40S TO NEAR 50 IN SOME LOCATIONS.
WEDNESDAY NIGHT AND THURSDAY...CONFIDENCE IS INCREASING IN A FAIRLY
STRONG LOW PRESSURE SYSTEM AFFECTING THE REGION.
THE MODELS ARE IN FAIRLY GOOD AGREEMENT THAT AN UPPER LEVEL TROUGH
DEVELOPING OVER THE MIDWEST WILL RESULT IN A STRONG LOW PRESSURE
SYSTEM. IN ADDITION...THE LATEST RUNS OF THE MODELS HAVE COME INTO
SOME AGREEMENT ON THE TRACK AND TIMING OF THIS SYSTEM. HOWEVER...
THIS IS A MUCH DIFFERENT TRACK FROM THAT OF 24 HOURS AGO. 00Z MODEL
RUNS FROM LAST NIGHT HAD THE LOW PRESSURE TRACKING JUST EAST OF CAPE
COD WHEREAS THE LATEST MODEL RUNS TRACK THE LOW PRESSURE ANYWHERE
FROM DETROIT /NAM/ TO NEW YORK STATE /GFS AND ECMWF/. THIS DRASTIC
CHANGE KEEPS QUITE A BIT OF UNCERTAINTY IN THE FORECAST. THE
GREATER IMPACT ON OUR AREA WILL ACTUALLY BE FROM AN INLAND TRACK
STORM AS WINDS WILL BE MUCH STRONGER AND FROM THE SOUTH...LEADING TO
THE POSSIBILITY OF COASTAL FLOODING ALONG THE SOUTH COAST.
REGARDLESS...WIND DRIVEN RAIN FOR A PERIOD FROM LATE WEDNESDAY NIGHT
THROUGH THURSDAY IS A GIVEN IN ALL OF THE ABOVE SOLUTIONS.
THEREFORE...HAVE NO PROBLEM KEEPING THE HIGH LIKELY POPS OR EVEN
POSSIBLY BUMPING THEM UP TO CATEGORICAL FOR AT LEAST A PORTION OF
THIS TIME FRAME. AT THIS POINT...SIGNIFICANT FLOODING DOESN/T LOOK
PROBABLE AS THE STORM IS MOVING AT A GOOD CLIP. THE USUAL POOR
DRAINAGE AND URBAN FLOODING IS LIKELY.
OUR MAIN CONCERNS FOR THIS EVENT WILL REVOLVE AROUND THE POTENTIAL
FOR STRONG WINDS AND PERHAPS EVEN COASTAL FLOODING ALONG THE SOUTH
COAST THURSDAY MORNING. HOWEVER...THERE REMAINS QUITE A BIT OF
UNCERTAINTY IN THESE TWO POTENTIAL SCENARIOS WITH THE INCONSISTENCY
IN TRACK FROM RUN TO RUN IN THE MODELS. IN ORDER FOR COASTAL
FLOODING ALONG THE SOUTH COAST AND STRONG WINDS TO OCCUR...THE LOW
WOULD HAVE TO PASS WEST OF THE REGION ALLOWING THE REGION TO WARM
SECTOR. WHILE THIS IS THE CURRENT MODEL SOLUTION...IT IS STILL A
WAYS OUT SO ITS NOT SET IN STONE. THE HIGHEST PROBABILITY FOR THE
STRONG WINDS WILL BE ALONG THE COASTAL PLAIN...BUT CAN NOT BE RULED
OUT ACROSS THE REST OF THE REGION DEPENDING UPON HOW FAR WEST THE
LOW TRACKS. FINALLY...A FEW EMBEDDED THUNDERSTORMS ARE POSSIBLE IN
THE WARM SECTOR THURSDAY MORNING BUT TOO MUCH UNCERTAINTY TO INSERT
INTO THE FORECAST THIS FAR OUT.
FRIDAY THROUGH SUNDAY...
MAINLY DRY AND SEASONABLY COOL WEATHER SHOULD FOLLOW BEHIND THE
DEPARTING STORM SYSTEM AS HIGH PRESSURE BUILDS INTO THE AREA.
&&
.AVIATION /09Z MONDAY THROUGH FRIDAY/...
TONIGHT...VFR...BUT LOWERING CIGS AND LOW PROB MVFR CONDITIONS IN
DEVELOPING SHOWERS EEN TO THE NW BAF AFTER 10Z. CONFIDENCE ABV AVG.
MON...BRIEF PERIOD OF MVFR CONDS IN BAND OF SHOWERS MOVING ACROSS THE
REGION. SW GUSTS TO 25 KT POSSIBLE FMH-HYA-ACK. WE MAY SEE IFR CONDS
DEVELOPING VCNTY ORH MIDDAY MONDAY IN SHOWERS... AND THEN BECOMING
EVIDENT FM PVD TO FMH/HYA ARD 21Z MONDAY "IF" SHOWERS DEVELOP AND EXPAND
IN COVERAGE AND INTENSITY ACROSS SNE AS WE ARE CURRENTLY FCSTG.
CONFIDENCE ON MVFR/IFR CIGS/VSBY FCST BELOW AVG. CONDS COULD BE VFR
IF SHOWERS ARE LESS THAN .10 IN SNE.
MONDAY NIGHT...IFR CONDS KACK KFMH AND KHYA /POSSIBLY PVD?/ DURING
THE EVENING BECOMING VFR WHILE ALL OTHER TAF SITES VFR. NW WINDS
G15-25 KTS BOS PVD ORH HYA ACK AND FMH IN CAA. CONFIDENCE ON IFR
CIGS/VSBYS IS BELOW AVG.
OUTLOOK /TUESDAY NIGHT THROUGH FRIDAY/...
TUESDAY NIGHT...VFR.
WEDNESDAY...MAINLY VFR.
WEDNESDAY NIGHT AND THURSDAY...MVFR/IFR CONDITIONS LIKELY IN LOW
CLOUDS AND HEAVY RAIN ALONG WITH THE POTENTIAL FOR A PERIOD OF
STRONG WIND GUSTS TO PORTIONS OF THE REGION.
FRIDAY...CONDITIONS SHOULD IMPROVE TO VFR.
&&
.MARINE...
TONIGHT...LOW LEVEL SW FLOW INCREASES LATE AND SCA WINDS MAY DEVELOP
LATE SOUTH COASTAL WATERS. BUILDING SEAS SOUTH COASTAL WATERS. SCA
SEAS CONTINUE SE OUTER WATERS. BUOY 44097 SW OF MVY REPORTING 5 FT
SEAS AS OF 10 PM.
MONDAY...BETTER CHANCE OF SCA WINDS WITH BRIEF MIDDAY G25-30 KT AS
SW LLJ INCREASES AND MILD TEMPS OVER THE WATER SUPPORTS SOME MIXING.
SEAS BUILD OVER OUTER SOUTHERN WATERS.
MONDAY NIGHT...SCA ANTICIPATED MANY WATERS IN A PRD OF CAA BUT CONFIDENCE
LESS THAN 80 PCT AND SO SCA NOT ISSUED ATTM. THERE IS MODEL DISAGREEMENT
REGARDING THE STRENGTH OF THE CAA GUSTS...12Z EC AND 18Z NAM BEING
WEAKER THAN WOULD PREFER FOR A 3RD PERIOD ISSUANCE OF THE SCA.
OUTLOOK /TUESDAY NIGHT THROUGH FRIDAY/...
TUESDAY NIGHT AND WEDNESDAY...WESTERLY WINDS 15 TO 20 KTS AND SEAS 3
TO 5 FEET WILL DIMINISH THROUGH THE PERIOD.
WEDNESDAY NIGHT AND THURSDAY...SEAS INCREASE AS A LOW PRESSURE
SYSTEM APPROACHES SOUTHERN NEW ENGLAND. SOUTHERLY GALE FORCE WINDS
ARE LIKELY WITH THIS STORM.
THURSDAY NIGHT AND FRIDAY...STRONG SMALL CRAFT WESTERLY WINDS ARE LIKELY
TO CONTINUE AS BOTH SEAS AND WINDS DIMINISH SLOWLY BEHIND THE
DEPARTING STORM SYSTEM. HIGH SEAS WILL LINGER...PARTICULARLY ON THE
SOUTHERN OUTER WATERS.
&&
.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.
CURRENTLY...WE ARE FORECASTING A LOW OF 34 AND 35 DEGREES ON THE
MORNINGS OF 12/1 AND 12/2...RESPECTIVELY. AVERAGE FIRST DATE OF 32 IN
BOSTON IS AROUND NOVEMBER 4TH. DESPITE THE POTENTIAL LATEST
OCCURRING FREEZING TEMP AT BOSTON... WE DID ESTABLISH THE 3RD
EARLIEST MINOR SNOWFALL AT LOGAN AIRPORT THIS FALL ON OCTOBER 18TH.
NOVEMBER WILL BE TOP 10 WARMEST... STATUS THRU 11/28
THERE ARE NO PROJECTIONS AS TO FINAL OUTCOME BUT A RANKING IN THE TOP
10 WARMEST IS ASSURED FOR MOST OR ALL OF THESE 100 PLUS YEAR LOCATIONS.
RECENT TOP 10 WARMEST WAS 2006...ONE OF THE WARMEST NOVEMBERS ON
RECORD.
BELOW IS THE CURRENT AVG FOR THE MONTH FROM OUR PRELIMINARY CF6...AS
WELL AS THE DEPARTURE FROM NORMAL...THE TOP 10 WARMEST RANKING AND
CLOSE WITH THE 2006 WARMEST NOV RANKING REFERENCE.
BOS 48.9 PLUS 3.7 RANKED A STRONG NUMBER 6 2006 WAS 4TH WARMEST
BDL 46.5 PLUS 4.4 RANKED NUMBER 5 2006 WAS 4TH WARMEST
PVD 49.0 PLUS 4.9 RANKED A SOLID NUMBER 3. 2006 WAS 2ND WARMEST.
ORH 44.8 PLUS 4.8 RANKED NUMBER 4. 2006 WAS WARMEST EVER NOV
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR ANZ232>234-
237.
SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 5 AM EST TUESDAY
FOR ANZ231-250-251.
SMALL CRAFT ADVISORY UNTIL 5 AM EST TUESDAY FOR ANZ235-254>256.
&&
$$
SYNOPSIS...RLG/GAF
NEAR TERM...GAF
SHORT TERM...GAF
LONG TERM...RLG
AVIATION...RLG/GAF
MARINE...RLG/GAF
CLIMATE...
