722
FXUS61 KBOX 271816
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
116 PM EST FRI NOV 27 2009
SYNOPSIS
A COASTAL STORM DEVELOPING EAST OF CAPE COD WILL MOVE INTO THE MARITIMES
TONIGHT AND SATURDAY. HIGH PRESSURE WILL BRING DIMINISHING WINDS AND
MILDER CONDITIONS SUNDAY. A COLD FRONT MOVES ACROSS THE AREA BRINGING
SHOWERS MONDAY AND MONDAY NIGHT...FOLLOWED BY COOLER AND DRIER
WEATHER TUESDAY AND WEDNESDAY.
NEAR TERM /UNTIL 9 PM THIS EVENING/
1249 PM UPDATE: ALL FORECAST PRODUCTS UPDATED THROUGH SATUR"DAY" JUST
AFTER NOON IN CONJUNCTION WITH OUR AVN GRIDDED FORECAST WHICH IS
POSTING MOMENTARILY. THAT MEANS OUR TEMPS/DEWS/SUSTAINED WINDS/MXG
HTS/GUSTS/POPS/SKY/QPF/WX WERE ALL UPDATED.
BOX STP HIGHLY OVER PREDICTED IN CT SW ORH CTY DUE TO EARLIER BRIGHT
BANDING.
TIDES: BIG SURGE OF ~1.5 FT AT 10 AM...ONLY MODEL PREDICTED .5 TO .7 FT.
INCREASED SURGE AND STORM TIDE THROUGH TONIGHT BUT ITS NOT A FACTOR
DUE TO LOW ASTRO. THIS A CONTG PROBLEM WITH MRPSSE FCSTS PREDICTING
HALF OF THE REALTIME STORM SURGE ON ONSHORE FLOW LOW PRES EVENTS.
THUNDER: WAS ONLY IN EMA WATERS SO FAR THRU 1730Z IN OUR CWA...PER
MODELED BEST INSTAB.
TEMPS ARE MID SHIFT FCST WITH SOME 16Z MATCH LAV.
POPS ARE 09Z SREF... WHICH KEEPS SHOWERY RAINS GOING OVER MOST OF SNE
THIS AFTN AS INTENSIFYING DEEP CCS DEVELOPS OVER HEAD.
WEATHER IS 50/50 BLENDED PARTIAL THICKNESSES FROM THE 12Z GFS/NAM.
THUNDER AT 50 50 BLENDED 12Z/27 NAM/GFS KI GREATER THAN 31.
SNOW WAS CUT OFF AT 35F DUE TO WARM BL TEMPS AND ASSOCIATED WARM BL
WET BULB.
SKY WAS 4AM FCST CONSISTENT W 12Z/27 RGEM/NAM 50 50 BLEND.
QPF WAS 50 PCT 12Z/27 QPF 30PCT 12Z NAM AND 20 PCT 12Z GFS QPF.
INCREASINGLY GUSTY NW WINDS THIS AFTN PER TIGHTENING GRADIENT AND
INCREASING BL INSTAB.
SHORT TERM /9 PM THIS EVENING THROUGH SATURDAY NIGHT/
1249 PM UPDATE: VERTICALLY STACKED LOW WILL SLOWLY DRIFT EWD FROM
GULF OF MAINE TONIGHT. AREA OF DEEPER MOISTURE AND OMEGA ROTATING
AROUND THE UPPER LOW WILL SWING THOUGH SNE TONIGHT AND LIKELY BRING
ANOTHER PERIOD OF SHOWERS...WITH MIXED RAIN/SNOW HIGHER TERRAIN SNH.
MINOR ACCUM POSSIBLE IN THE NW HIGHER TERRAIN BUT NOT LIKELY DUE TO
WARM BL. SFC TEMPS MAY HOLD STEADY OR EVEN SLOWLY RISE TONIGHT AS MID
LEVEL COLD POOL MOVES EWD.
WIND ADVY CONTS AS PREVIOUSLY ADVERTISED FM THE MID SHIFT. NAM GUST
ALG WITH THE MORE CONSERVATIVE OUTPUT AND USED FOR THIS AFTN. GFS
WOULD SUGGESTION HIGH WIND POTENTIAL SE CAPE COD AND THE ISLANDS AND
DIDNT WANT TO GO THAT ROUTE YET.
THE WIND ADVISORY WILL CONTINUE THROUGH AT LEAST MIDDAY SATURDAY...
BEST BETS FOR WINDS WOULD BE OVER THE CAPE AND ISLANDS AND OVER THE
HIGHER ELEVATIONS OF THE INTERIOR.
WE MAY NEED TO EXTEND THE ADVY THROUGH 3 PM SAT AND WILL REEVALUATE
FOR THE 4PM PKG.
SAT NIGHT...WINDS DIMINISH. NO POPS AND WX.
LONG TERM /SUNDAY THROUGH THURSDAY/
SUNDAY...HIGH PRESSURE BUILDS OVER THE REGION.
THE NEXT WEATHER MAKER WILL BE A COLD FRONT MOVING ACROSS FROM THE
GREAT LAKES. CLOUDS LEADING THE FRONT MAY REACH US LATE SUNDAY...BUT
MOST INCREASE IN CLOUDS WILL OCCUR SUNDAY NIGHT. THE VARIOUS MODELS
HAVE DIFFERENT TIMING FOR THIS FRONT...WITH THE NAM AND GFS FASTER
AND THE ECMWF SLOWER. WITH THE DIGGING OF AN UPPER TROF OVER THE
LAKES AND RESULTING SOUTHWEST FLOW OVER US...WE PREFER THE SLOWER
ECMWF SCENARIO. THIS WOULD BRING THE FRONT THROUGH LATE MONDAY OR
MONDAY NIGHT. EXPECT LIGHT SHOWERS...THE PRECIP TYPE SHOULD MOSTLY BE
RAIN BUT FORECAST THERMAL PROFILES SHOW A POTENTIAL FOR A CHANGE TO
SNOW MONDAY NIGHT AFTER THE COLD FRONT MOVES THROUGH ESPECIALLY IN
THE NORTH AND WEST. THIS COULD BRING AN INCH OR TWO OF SNOW TO THE
BERKSHIRE EAST SLOPES/MONADNOCKS/NORTHERN WORCESTER HILLS.
TUESDAY AND WEDNESDAY LOOK DRY AND COOL AS HIGH PRESSURE MOVES
THROUGH. THE GFS SHOWS ANOTHER COASTAL LOW MOVING PAST ON WEDNESDAY
NIGHT...THE ECMWF BRINGS IT THROUGH ON THURSDAY. WILL FAVOR THE ECMWF
SOLUTION AND FORECAST CHANCE POPS FOR THURSDAY.
AVIATION /18Z FRIDAY THROUGH WEDNESDAY/
18Z TAFS POSTED. WERE AVN GRID BASED WHICH INCLUDED BOX GRIDS OF POPS/WX/
VSBY/SUSTAINED AND WIND GUSTS DERIVED AS PER NEAR TERM SECTION.
THIS AFTERNOON...WIDESPREAD MVFR CIGS WITH AREAS MVFR VSBYS IN FOG
AND SHOWERS. THERE WILL BE LOCALIZED IFR CIGS/VSBYS PARTICULARLY ON
THE CAPE AND ISLANDS. MAY SEE A MIX WITH SNOW HIGHER ELEVATIONS IN
SOUTHERN NH. WEST WIND GUSTS INCREASE TO 25 TO 30 KTS MANY TERMINALS
BY 00Z.
TONIGHT...GUSTY WEST WINDS OF 35 TO 40 KT ANTICIPATED ACROSS MOST
TERMINALS...ESPECIALLY HYA-ACK-FMH AND ORH. MVFR CIGS/VSBYS IN
SHOWERS EXCEPT CIGS IMPROVING TO VFR BDL VCNTY IN THE EVENING. CIGS
GENERALLY IMPROVE TO VFR AFTER MIDNIGHT BUT AREAS OF MVFR VSBYS IN
SHOWERS AND FOG LINGER.
PLS SEE TAFS FOR DETAILS.
SATURDAY...GENERALLY VFR CIGS EARLY THEN CLEARING STEADILY FM W TO E.
STRONG NORTHWEST WINDS THROUGH AT LEAST MIDDAY WITH SUSTAINED WINDS
20 TO 30 KNOTS AND GUSTS 40 TO 45 KNOTS. WINDS WILL DIMINISH LATE
SATURDAY.
SAT NIGHT...VFR WINDS DIMINISHING. POSSIBLE MVFR CIG LATER AT NIGHT
INTERIOR.
OUTLOOK /SATURDAY THROUGH TUESDAY/...
SUNDAY...VFR.
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
THROUGH SAT NIGHT...HEADLINES POSTED AS PER 4AM. STRONG GALE CENTER
EVOLVING TO A STORM ATTM. GUSTS TO 45 KT LIKELY OVER THE SOUTH COASTAL
WATERS AND 35-40 KT ELSEWHERE TONIGHT THROUGH EARLY SAT AFTN. LOW PROB
FOR STORM FORCE WINDS 3AM TO NOON EST SOUTHERN WATERS.
SAT NIGHT...DIMINISHING WIND WITH LEFTOVER HEADLINES.
OUTLOOK /SATURDAY THROUGH TUESDAY/...
SATURDAY...NORTHWEST GALES CONTINUE...WITH WINDS DIMINISHING SATURDAY
NIGHT. SEAS BUILDING TO 8 TO 15 FEET ON THE OUTER WATERS...SUBSIDING
AFTER MIDNIGHT.
SUNDAY...WINDS AT SMALL CRAFT ADVISORY LEVEL IN THE MORNING BUT
DROPPING BELOW 25 KNOTS AFTERNOON. SEAS DIMINISH BELOW 5 FEET ON THE
INNER WATERS...BUT REMAIN AT OR ABOVE 5 FEET ON THE OUTER WATERS.
MONDAY-TUESDAY...INCREASING SEAS AND SOUTHWEST WINDS AHEAD OF A COLD
FRONT. WINDS AND SEAS MAY REACH SMALL CRAFT ADVISORY LEVELS.
CONDITIONS CONTINUE IN THE NORTHWEST FLOW BEHIND THE FRONT TUESDAY.
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.
EQUIPMENT
TBOS TDWR CONT OTS.
BOX WATCHES/WARNINGS/ADVISORIES
CT...WIND ADVISORY FROM 6 PM THIS EVENING TO NOON EST SATURDAY FOR
CTZ002>004.
MA...WIND ADVISORY FROM 6 PM THIS EVENING TO NOON EST SATURDAY FOR
MAZ002>024-026.
NH...WIND ADVISORY FROM 6 PM THIS EVENING TO NOON EST SATURDAY FOR
NHZ011-012-015.
RI...WIND ADVISORY FROM 6 PM THIS EVENING TO NOON EST SATURDAY FOR
RIZ001>008.
MARINE...GALE WARNING UNTIL 3 PM EST SATURDAY FOR ANZ232>235-237-255-
256.
GALE WARNING FROM 6 PM THIS EVENING TO 3 PM EST SATURDAY FOR
ANZ230-231-236-250-251-254.
SYNOPSIS...WTB/KJC/DRAG
NEAR TERM...DRAG
SHORT TERM...DRAG
LONG TERM...WTB
AVIATION...WTB/DRAG/NMB 115 P UPDATED SAT AND SAT NIGHT
MARINE...WTB/DRAG
CLIMATE...
EQUIPMENT...
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page