FXUS61 KBOX 272152
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
452 PM EST FRI NOV 27 2009
.SYNOPSIS...
A COASTAL STORM DEVELOPING EAST OF CAPE COD LATE THIS AFTERNOON WILL
LIFT INTO THE CANADIAN MARITIMES SATURDAY MORNING...BRINGING AN END
TO THE PRECIPITATION. A COLD FRONT WILL APPROACH THE REGION MONDAY
AND MONDAY EVENING BRINGING A PERIOD OF RAIN SHOWERS...FOLLOWED BY
DRIER AND CHILLIER WEATHER TUESDAY. ANOTHER LOW PRESSURE SYSTEM
WILL BRING THE POTENTIAL FOR MORE RAIN WEDNESDAY NIGHT AND THURSDAY
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
THE FORECAST THROUGH SATURDAY WAS GENERATED AT NOON IN CONJUNCTION
WITH OUR AVN GRIDDED FORECAST. THAT MEANS OUR TEMPS/DEWS/SUSTAINED
WINDS/MXG HTS/GUSTS/POPS/SKY/QPF/WX HAVE NOT BEEN UPDATE FOR LATE
TONIGHT AND SATURDAY SINCE NOON TODAY. THEY ARE COLLABORATED AND IN
GENERAL AGREEMENT WITH SURROUNDING OFFICES.
BOX STP HIGHLY OVER PREDICTED IN CT SW ORH CTY DUE TO MORNING BRIGHT
BANDING.
TIDES: STILL A LARGE SURGE OF ~1 FT AT 4 PM...ABOVE THE PREDICTED .5 TO
.7 FT. INCREASED SURGE AND STORM TIDE THROUGH TONIGHT BUT ITS NOT A
FLOODING FACTOR DUE TO LOW ASTRO. THIS A CONTG PROBLEM WITH MRPSSE
FCSTS PREDICTING HALF OF THE REALTIME STORM SURGE ON ONSHORE FLOW ELY
GRADIENT EVENTS.
THUNDER: WAS ONLY IN EMA WATERS SO FAR ARD 15-16Z IN OUR CWA...PER
MODELED BEST INSTAB.
THROUGH SAT NIGHT THE FOLLOWING GRIDDED GUIDANCE WAS APPLIED...
POPS WERE 09Z SREF... WHICH KEEPS SHOWERY RAINS GOING OVER MOST OF
SNE THIS EVENING AS INTENSIFYING DEEP CCS DEVELOPS OVER HEAD.
WEATHER IS GENERATED FROM A 50/50 BLEND OF PARTIAL THICKNESSES FROM THE
12Z GFS/NAM.
THUNDER IS 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 A 50 50 BLEND OF 12Z RGEM AND NAM.
QPF WAS 50 PCT 12Z/27 HPCQPF 30PCT 12Z NAM AND 20 PCT 12Z GFS QPF.
INCREASINGLY GUSTY NW WINDS TONIGHT...ESP COAST AND HIGH TERRAIN
PER TIGHTENING GRADIENT AND INCREASING BL INSTAB.
SHOWERS ROTATING ARD NEAR VERTICALLY STACKED CCS...WITH A BAND
SWINGING SEWD THRU MUCH OF THE FA LATE TONIGHT.
WHILE A BIT OF SNOW IS POSSIBLE IN THE HIGH TERRAIN...ESP NW MASS...BUT
THE BL APPEARS ABV FREEZING IN TOO DEEP A LAYER AND DID NOT FCST
SNOW AMTS...NOR DOES HPC. BUT THIS STILL NEEDS TO BE MONITORED. THE
MARGINALLY COLDER AIR IS INGESTING FROM THE ADIRONDACKS AND
CATSKILLS. 18Z NAM SFC TEMPS APPEAR TOO COLD AS COMPARED TO ITS OTHER
SIGMA LAYER PLAN VIEW TEMPS THAT WE SEE IN AWIPS. 18Z GFS SUPPORTS NO
SNOW OR JUST SPITS OF SNOW ABV 1500 FT.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
SAT...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 SUGGEST HIGH WIND POTENTIAL SE CAPE COD AND THE
ISLANDS AND DIDNT WANT TO GO THAT ROUTE YET FOR THE 11Z-19Z SATURDAY
TIME FRAME. MID SHIFT REEVAL.
THE WIND ADVISORY WILL CONTINUE THROUGH AT LEAST EARLY SATURDAY AFTN...
BEST BETS FOR WINDS WOULD BE OVER THE CAPE AND ISLANDS AND OVER THE
HIGHER ELEVATIONS OF THE INTERIOR. MAY NEED TO EXTEND WIND ADVY ON CC
AND THE ISLANDS TIL 6 PM IN FUTURE FCSTS.
ALSO LOW PROBABILITY WE WILL NEED A HWW FOR CC AND THE ISLANDS.
SKYWARN WILL BE REMOTELY MONITORING FOR CRITERIA AND OR DAMAGE. WE
MAY NEED SAT MORNING IN OFFICE SKYWARN PRESENCE.
A LARGE STRONG CIRCULATION WITH PRES RISES AND DRIER AIR ARRIVING
PERMITTING CLEARING AFTER EARLY MORNING SCT SHOWERS IN THE EAST.
SAT NIGHT...WINDS DIMINISH. NO POPS AND WX AS RDG OF HIGH PRES
APPROACHES.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
SUNDAY...
CONFIDENCE IS VERY HIGH IN A TRANQUIL WEATHER DAY. WESTERLY FLOW
ALOFT WILL PROVIDE FOR A PARTLY TO MOSTLY SUNNY DAY ALONG WITH
TEMPERATURES SLIGHTLY ABOVE SEASONAL NORMALS. HIGHS SHOULD MAINLY
BE IN THE UPPER 40S AND LOWER 50S.
SUNDAY NIGHT...
LOW PRESSURE TRACKING NORTHEAST TOWARDS THE GREAT LAKES WILL INDUCE
WARM AIR ADVECTION IN THE MID LEVELS OF THE ATMOSPHERE. WHILE WE
EXPECT CONDITIONS TO REMAIN DRY FOR MOST OF THE NIGHT...SKIES SHOULD
GENERALLY BE PARTLY TO MOSTLY CLOUDY. A FEW SHOWERS MAY ENTER OUR
DISTANT INTERIOR ZONES TOWARD 12Z MONDAY. THE INCREASE IN CLOUD
COVER SHOULD HOLD OVERNIGHT LOWS MAINLY IN THE 30S...TO THE LOWER
40S.
MONDAY AND MONDAY NIGHT...
LOW PRESSURE TRACKING WELL NORTH OF OUR REGION ACROSS NORTHERN NEW
ENGLAND WILL DRAG A COLD FRONT THROUGH OUR REGION. THIS SHOULD
PRODUCE ENOUGH LIFT TO RESULT IN A PERIOD OF RAIN SHOWERS DURING THE
DAY MONDAY INTO MONDAY EVENING. WILL RUN WITH A PERIOD OF LIKELY POPS TO
COVER THIS SCENARIO. CONFIDENCE IS HIGH THAT THE MOST OF WHAT FALLS
WILL BE IN THE LIQUID FORM. IT MAY BE COLD ENOUGH FOR THE
PRECIPITATION TO END AS A BRIEF PERIOD OF SNOW SHOWERS ACROSS THE
HIGHER TERRAIN...WITH THE BEST CHANCE ACROSS THE EAST SLOPES OF THE
BERKSHIRES AND MONADNOCKS. HOWEVER...MOST OF THE SIGNIFICANT
PRECIPITATION WILL BE OVER BY THEN SO IF THERE ARE ANY ACCUMULATIONS
IN THIS REGION THEY SHOULD BE RATHER LIGHT.
HIGHS ON MONDAY SHOULD RANGE FROM THE 40S ACROSS THE INTERIOR...TO
WELL UP INTO THE 50S ALONG THE COASTAL PLAIN. COLDER AIR WILL WORK
INTO THE REGION MONDAY NIGHT AND LOWS SHOULD FALL INTO THE UPPER 20S
TO MID 30S OVERNIGHT.
TUESDAY...
A BLUSTERY AND CHILLY DAY LOOKS TO BE ON TAP BEHIND THE FRONT...BUT
CERTAINLY NOTHING EXTRAORDINARY FOR THIS TIME OF YEAR. 850 MB
TEMPERATURES AROUND -10C...SHOULD HOLD HIGH TEMPERATURES IN THE LOW
TO MID 40S ACROSS MOST OF THE REGION. IN FACT...PORTIONS OF THE
INTERIOR HIGH TERRAIN MAY STRUGGLE TO REACH 40. IN ADDITION...GUSTY
NORTHWEST WINDS WILL MAKE IT FEEL QUITE CHILLY CONSIDERING OUR
RECENT WEATHER. SHOULD GENERALLY BE A DRY DAY...ALTHOUGH A FEW
SPRINKLES OR SNOW FLURRIES CAN NOT BE RULED OUT ACROSS THE HIGHER
TERRAIN OF THE DISTANT INTERIOR.
WEDNESDAY AND THURSDAY...
A WEAK RIDGE OF HIGH PRESSURE SHOULD KEEP THINGS DRY DURING THE DAY
WEDNESDAY. THE POTENTIAL EXISTS FOR A FAIRLY STRONG LOW PRESSURE
SYSTEM TO AFFECT THE REGION WEDNESDAY NIGHT AND THURSDAY.
THE MODELS ARE IN FAIRLY GOOD AGREEMENT THAT A DECENT UPPER LEVEL
TROUGH DEVELOPING OVER THE MIDWEST WILL SPAWN A PRETTY STRONG LOW
PRESSURE SYSTEM...BUT THE MODELS DISAGREE ON THE TRACK. THIS IS
STILL A LONG WAY OUT THOUGH AND JUST BECAUSE THE MODELS ARE IN GOOD
AGREEMENT IN SHOWING A DECENT STORM...DOES NOT MEAN THE EVENT IS IN
THE BAG. HOWEVER...THERE IS CERTAINLY THE POTENTIAL FOR A STRONG
LOW PRESSURE IMPACTING THE REGION WEDNESDAY NIGHT INTO THURSDAY. THE
MODEL TRACK AND TIMING ARE OF COURSE UNCERTAIN AT THIS POINT.
CONFIDENCE IS HIGH ENOUGH THOUGH TO INCLUDE HIGH CHANCE POPS
WEDNESDAY NIGHT AND THURSDAY. WHILE ITS A LONG WAY OFF...AT THIS
POINT WE ARE EXPECTING MAINLY A RAIN EVENT. ITS POSSIBLE THAT THERE
COULD BE SOME WET SNOW ACROSS THE INTERIOR IF THE SYSTEM ENDS UP
TAKING AN EASTERN MOST ROUTE...BUT ODDS FAVOR MOST OF THE EVENT
FALLING AS RAIN BASED ON THE CURRENT DATA.
THURSDAY NIGHT AND FRIDAY...
BLUSTERY AND CHILLY WEATHER SHOULD FOLLOW BEHIND THE DEPARTING STORM
SYSTEM. OF COURSE CONFIDENCE IS ALWAYS LOW THIS FAR OUT INTO A
FORECAST.
&&
.AVIATION /22Z 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.
LATE THIS AFTERNOON...WIDESPREAD MVFR CIGS WITH AREAS MVFR VSBYS IN
FOG AND SHOWERS. THERE WILL BE LOCALIZED IFR CIGS/VSBYS PARTICULARLY
ORH. NWEST WIND GUSTS INCREASE TO 20 TO 30 KTS.
TONIGHT...GUSTY WEST WINDS OF 30 TO 40 KT ANTICIPATED ACROSS MOST
TERMINALS...ESPECIALLY HYA-ACK-FMH AND ORH. MVFR CIGS/VSBYS IN
SHOWERS EXCEPT CIGS IMPROVING TO VFR BDL/BAF VCNTY LATE IN THE
EVENING. CIGS GENERALLY IMPROVE TO VFR AFTER MIDNIGHT BUT AREAS OF
MVFR VSBYS IN SHOWERS AND FOG LINGER ORH PVD EWD.
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 /SUNDAY THROUGH WEDNESDAY/...
SUNDAY...VFR.
MONDAY INTO MONDAY EVENING...A PERIOD OF MVFR CONDITIONS ARE LIKELY
IN LOW CLOUDS/RAIN SHOWERS.
TUESDAY AND WEDNESDAY...MAINLY VFR THROUGH WEDNESDAY AFTERNOON
ALTHOUGH COULD BE SOME MARGINAL MVFR CONDITIONS ACROSS THE DAY ON
TUESDAY.
&&
.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 5AM TO NOON EST SOUTHERN WATERS.
SAT NIGHT...DIMINISHING WIND WITH EVENTUAL LEFTOVER HEADLINES.
OUTLOOK /SUNDAY THROUGH WEDNESDAY/...
SUNDAY...WESTERLY WIND GUSTS OF 20 TO 25 KNOTS ARE EXPECTED WITH SCA
SEAS PERSISTING ACROSS THE OUTER-WATERS.
MONDAY...WINDS WILL INCREASE TO SCA LEVELS ACROSS MANY OF OUR WATERS
DURING THE DAY AHEAD OF AN APPROACHING COLD FRONT. SEAS WILL ALSO
BE ABOVE SCA LEVELS ACROSS MUCH OF OUR SOUTHERN WATERS.
MONDAY NIGHT AND TUESDAY...HIGH CONFIDENCE IN STRONG SCA TO A PERIOD
OF MARGINAL GALE FORCE NORTHWEST WIND GUSTS MONDAY NIGHT AND TUESDAY.
THIS A RESULT OF COLD ADVECTION OVER THE RELATIVELY WARM OCEAN
RESULTING IN GREAT MIXING.
TUESDAY NIGHT AND WEDNESDAY...WINDS SHOULD DIMINISH A BIT BUT WILL
PROBABLY REMAIN AT SCA LEVELS FOR MOST OF THE OPEN WATERS AS THERE
WILL STILL BE GOOD MIXING. SEAS WILL ALSO REMAIN ABOVE SCA
THRESHOLDS MOST OF THE TIME ACROSS THE OUTER-WATERS.
&&
.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 UNTIL 2 PM EST SATURDAY FOR CTZ002>004.
MA...WIND ADVISORY UNTIL 2 PM EST SATURDAY FOR MAZ002>024-026.
NH...WIND ADVISORY UNTIL 2 PM EST SATURDAY FOR NHZ011-012-015.
RI...WIND ADVISORY UNTIL 2 PM EST SATURDAY FOR RIZ001>008.
MARINE...GALE WARNING UNTIL 5 PM EST SATURDAY FOR ANZ232>235-237-255-
256.
GALE WARNING UNTIL 5 PM EST SATURDAY FOR ANZ230-231-236-250-
251-254.
&&
$$
SYNOPSIS...DRAG/FRANK
NEAR TERM...DRAG 451
SHORT TERM...DRAG 451
LONG TERM...FRANK
AVIATION...DRAG/FRANK/NMB 451
MARINE...DRAG/FRANK 451
CLIMATE...
EQUIPMENT...
