FXUS61 KBOX 261205
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
705 AM EST THU NOV 26 2009
.SYNOPSIS...
WEAK HIGH PRESSURE WILL REMAIN ACROSS NEW ENGLAND TODAY AS A COASTAL
LOW DEVELOPS OFF THE MID ATLC COAST. THIS STORM WILL RAPIDLY
INTENSIFY AS IT TRACKS NEAR NANTUCKET EARLY FRIDAY...THEN MOVE
NORTHEAST THROUGH THE MARITIMES FRIDAY NIGHT AND SATURDAY BRINGING
STRONG NORTHWEST WINDS. HIGH PRESSURE WILL BRING DIMINISHING WINDS
SUNDAY. ANOTHER LOW PRESSURE AND FRONTAL SYSTEM SHOULD MOVE THROUGH
NEW ENGLAND EARLY NEXT WEEK...FOLLOWED BY HIGH PRESSURE WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WEAK SFC RIDGING WILL REMAIN ACROSS SNE TODAY WITH INCREASING SW
FLOW ALOFT AHEAD OF AMPLIFYING MID LEVEL TROF. TIME SECTIONS
CONTINUE TO INDICATE ABUNDANT LOW LEVEL MOISTURE...AND WITH LIGHT
BOUNDARY LAYER WINDS...IT WILL BE DIFFICULT TO SCOUR OUT THIS
MOISTURE. ALSO...HIGH CLOUDS STREAMING NWD WILL LIMIT THE HEATING
NECESSARY TO ERODE THE LOW CLOUDS. IT ALL ADDS UP TO ANOTHER CLOUDY
DAY WITH AREAS OF FOG...LOCALLY DENSE THIS MORNING.
GFS/ECMWF BRING LIGHT QPF TO SNE AFT 18Z AS WEAK ISENTROPIC LIFT
MOVES INTO REGION AND THIS MAY BE MORE INDICATIVE OF AREAS OF
DRIZZLE THAN SHOWERS. NAM/UKMET/GGEM DRY TODAY. WE WILL BRING IN
CHC POPS TO SE NEW ENG THIS AFTERNOON WITH SLIGHT CHC ELSEWHERE.
TEMPS...USED A BLEND OF COOLER MET GUIDANCE WITH THE MAV GIVEN THE
ABUNDANT CLOUD COVER.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
SIGNIFICANT TROF AMPLIFICATION OCCURS FROM THE GT LAKES TO MID ATLC
COAST TONIGHT WITH CYCLOGENESIS SOUTH OF NEW ENG TONIGHT IMPRESSIVE
HEIGHT FALL CENTER MOVES OFF THE MID ATLC COAST. THERE IS STILL
SOME UNCERTAINTY WITH THE TRACK/INTENSITY THROUGH 12Z FRI BASED ON
DIFFERENCES IN THE HANDLING OF THE SHORTWAVE ENERGY MOVING OFF THE
COAST. WE ARE LEANING TOWARD GFS WHICH HAS SUPPORT FROM THE
SREF/UKMET...AND MAJORITY OF GEFS ENSEMBLE MEMBERS ARE CLUSTERED
NEAR THE OP GFS. THIS TAKES DEEPENING LOW TO NEAR NANTUCKET BY 12Z
FRI.
WE BLENDED THE SREF/GMOS POPS TONIGHT WHICH BRINGS RAIN NORTHWARD
INTO SNE THIS EVENING WITH RAIN BECOMING WIDESPREAD BY MIDNIGHT.
GFS HAS NICE THUNDER SIGNAL 12Z FRI OVER THE CAPE/ISLANDS WITH
RATHER UNSTABLE SWI AND TT LOW TO MID 50S SO WE ADDED SLIGHT CHC
THUNDER TO THE GRIDS FOR CAPE/ISLANDS LATE TONIGHT.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
26/00Z MODELS ARE IN FAIRLY GOOD AGREEMENT WITH THIS PORTION OF THE
FORECAST. THIS IS NOT TO SAY THERE ARE NO SIGNIFICANT DIFFERENCES IN
SOME ASPECTS OF THE MAIN WEATHER PLAYERS.
EXCELLENT AGREEMENT BETWEEN THE 26/00Z GFS AND GEFS MEAN...AS WELL AS
THE 25/21Z SREF MEAN...WHICH HAS MORE NAM-BASED MEMBERS THAN OTHER
MODELS...GIVES GOOD CONFIDENCE IN THE GFS SOLUTION FOR FRIDAY INTO
SATURDAY. THE OPERATIONAL NAM HAS A STORM TRACK ALONG THE EASTERN
ENVELOPE OF SOLUTIONS...ALONG WITH THE GGEM AND ECMWF. HOWEVER...
THESE MODELS ALL TREND WEST TOWARD THE GFS SOLUTION...WITH GOOD
CLUSTERING BY 00Z SUNDAY. WILL USE A BLEND OF THE GUIDANCE...MORE
HEAVILY WEIGHTED TOWARD THE GFS...FOR FRIDAY INTO SATURDAY.
GFS...GEFS AND ECMWF ARE CLOSE ENOUGH TO HAVE CONSERVATIVE CONFIDENCE
IN USING 00Z GUIDANCE TO TREND PREVIOUS FORECAST SATURDAY NIGHT INTO
NEXT WEDNESDAY.
THE BIGGEST CONCERN HEADING INTO THIS HOLIDAY WEEKEND WILL BE THE
ARRIVAL OF STRONG WEST TO NORTHWEST WINDS FRIDAY NIGHT INTO SATURDAY.
WE MAY NEED TO CONSIDER A WIND ADVISORY...MAINLY FOR THE CAPE AND
ISLANDS AND SOUTH COAST BUT POTENTIALLY FOR HIGHER ELEVATIONS INLAND.
CONFIDENCE IS NOT YET HIGH ENOUGH TO DEFINE LOCATIONS AT RISK SINCE
THE LOW LEVEL LAPS RATES WILL BE CRITICAL.
NOT EXPECTING MUCH SNOWFALL WITH THIS PARTICULAR STORMS SINCE MOST OF
THE PRECIPITATION SHOULD DEPART SOUTHERN NEW ENGLAND BEFORE THE
ARRIVAL OF COLDER AIR ALOFT. COULD SEE SOME WET SNOWFLAKES AT
ELEVATIONS ABOVE 700 FT THOUGH.
HIGH PRESSURE BRINGS GENERAL CLEARING/DRY WEATHER FOR SUNDAY.
STILL SOME TIMING ISSUES WITH A COLD FRONTAL PASSAGE EARLY NEXT WEEK.
DECENT AGREEMENT WITH THE GFS AND ECMWF FOR THIS TIME RANGE...SO DID
UPDATE THE TIMING TO BE MORE IN LINE WITH LATEST GUIDANCE.
STILL LOW CONFIDENCE WITH THE WEDNESDAY FORECAST...WITH POTENTIAL FOR
A LOW PRESSURE TO ARRIVE FROM THE SOUTHWEST LATE IN THE DAY.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
HIGH CONFIDENCE ON LOW CIGS/VSBYS WITH IFR/LIFR CONDITIONS THROUGH
MID MORNING. SOME IMPROVEMENT EXPECTED INTO THE AFTERNOON WITH VSBYS
IMPROVING TO MVFR/VFR AND CIGS LIFTING TO MVFR...ESPECIALLY BDL-BAF-
MHT. FROM BOS-PVD SE TO CAPE/ISLANDS...ONLY A BRIEF PERIOD OF MVFR
CIGS EXPECTED THIS AFTERNOON BEFORE FALLING BACK TO IFR. SOME
DRIZZLE POSSIBLE BUT MAINLY DRY TODAY.
TONIGHT...WIDESPREAD IFR/LIFR CONDITIONS WITH RAIN OVERSPREADING THE
REGION FROM SOUTH TO NORTH.
OUTLOOK /FRIDAY THROUGH MONDAY/...
FRIDAY...WIDESPREAD IFR CIGS AND VSBYS IN RAIN AND FOG. FLIGHT
CONDITIONS IMPROVING TO MVFR IN THE AFTERNOON.
FRIDAY NIGHT AND SATURDAY...MVFR CONDITIONS IMPROVE TO VFR. STRONG
SURFACE WINDS WITH W WIND GUSTS 35-40 KT AND ASSOCIATED MECHANICAL
TURBULENCE. WINDS DIMINISH LATE SATURDAY/SATURDAY NIGHT.
SUNDAY AND MONDAY...VFR.
&&
.MARINE...
LIGHT EASTERLY WINDS TODAY WILL INCREASE LATER TONIGHT AS DEEPENING
COASTAL LOW APPROACHES FROM THE SOUTH. SCA NE WIND GUSTS TO 30 KT
LIKELY LATE TONIGHT ACROSS EASTERN WATERS WITH LOW PROB FOR MARGINAL
GALE AS LOW LEVEL JET DEVELOPS. LESS WIND EXPECTED OVER SOUTH
COASTAL WATERS TONIGHT AS LLJ AXIS ORIENTED ACROSS EASTERN WATERS.
OUTLOOK /FRIDAY THROUGH MONDAY/...
POTENTIAL FOR A PROLONGED PERIOD OF GALE TO STORM FORCE WINDS
SOMETIME FRIDAY INTO SATURDAY NIGHT. CONFIDENCE IN GALE FORCE WINDS
IS HIGHER. SO...POSTED A GALE WATCH FRIDAY INTO FRIDAY NIGHT FOR NOW.
THIS TIMING WILL LIKELY BE ADJUSTED IN LATER FORECASTS. WINDS
DIMINISH SATURDAY NIGHT INTO SUNDAY...BUT COULD STILL GUST UP TO
25 KT INTO MONDAY. SEAS SHOULD REMAIN ROUGH ACROSS THE OUTER WATERS
INTO AT LEAST SUNDAY NIGHT.
PERSISTENT ONSHORE FLOW AND 6 TO 8 FOOT EAST SWELLS COULD LEAD TO
MINOR BEACH EROSION ACROSS THE EASTERN MASSACHUSETTS COAST EARLY
FRIDAY. WE COULD SEE A SURGE OF 1.0 TO 1.5 FT DURING THE TIMES OF
HIGH TIDE FRIDAY BUT ASTRONOMICAL TIDES ARE QUITE LOW.
&&
.CLIMATE...
IT IS INTERESTING TO NOTE THAT BOSTON/S LOGAN AIRPORT HAS NOT GOTTEN
DOWN 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...NONE.
NH...NONE.
RI...NONE.
MARINE...GALE WATCH FROM FRIDAY MORNING THROUGH LATE FRIDAY NIGHT FOR
ANZ230>237-250-251-254>256.
SMALL CRAFT ADVISORY FROM 1 AM TO 6 AM EST FRIDAY FOR ANZ231-
232-255.
SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ250-251-254.
&&
$$
SYNOPSIS...KJC/BELK
NEAR TERM...KJC/BELK
SHORT TERM...KJC
LONG TERM...BELK
AVIATION...KJC/BELK
MARINE...KJC/BELK
CLIMATE...EKSTER
