FXUS61 KBOX 112219
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
520 PM EST FRI DEC 11 2009
.SYNOPSIS...
LARGE LOW PRES OVER SE CANADA WILL CONTINUE TO GENERATE BLUSTERY AND
UNSEASONABLY COLD WEATHER ACROSS SOUTHERN NEW ENGLAND THROUGH SAT. A
WEAK WAVE OF LOW PRESSURE AND ASSOCIATED FRONT WILL PUSH ACROSS THE
REGION SUNDAY AFTERNOON AND NIGHT. WEAK HIGH PRES FOLLOWS MON
PROVIDING DRY AND SEASONABLE TEMPS. ANOTHER LOW WILL MOVE ACROSS
SOUTHERN QUEBEC TUESDAY...WITH ITS ASSOCIATED FRONT MOVING OFF THE
COAST TUESDAY NIGHT. THE LOW WILL STALL ACROSS THE MARITIMES WHILE
HIGH PRESSURE REMAINS OVER THE MIDWEST INTO CENTRAL CANADA. THIS
WILL BRING DRY BUT VERY COLD AND BLUSTERY WEATHER FOR THE MIDDLE AND
END OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
WIND SPEEDS REMAINING BELOW WIND ADVISORY LEVELS THIS AFTERNOON.
KBOX 88D SHOWING SOME ECHOES...BUT ALL SURFACE OBSERVATION INDICATE
THIS IS VIRGA. WITH DEW POINTS IN THE SINGLE DIGITS AND THE MAIN MID
LEVEL TROUGH TO OUR EAST BY THIS EVENING...DO NOT THINK A MENTION OF
SNOW SHOWERS OR FLURRIES IS WARRANTED. GUSTY WEST WINDS CONTINUE
THROUGH TONIGHT.
MAV GUIDANCE TEMPERATURES ARE TOO HIGH THE REST OF THIS AFTERNOON...
BUT LOOK REASONABLE TONIGHT. MET GUIDANCE TEMPERATURES ARE IN MUCH
BETTER AGREEMENT WITH LATEST OBSERVATIONS. FOLLOWING THE MET GUIDANCE
FOR THE REMAINDER OF THIS AFTERNOON...THEN USED A BLEND WEIGHT MORE
TOWARD THE NAM OVERNIGHT.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
HIGH PRESSURE EXPECTED TO MOVE EAST THROUGH THE MID ATLANTIC STATES
DURING THE DAY SATURDAY. THE SURFACE RIDGE SHOULD CREST ACROSS NEW
ENGLAND SATURDAY NIGHT. EXPECTING NEAR NORMAL TO BELOW NORMAL
TEMPERATURES SATURDAY AND SATURDAY NIGHT. MET GUIDANCE LOOKS TO BE
HANDLING THE COLDER AIR BETTER SATURDAY...SO LEANED IN THAT
DIRECTION. A BLEND OF THE GFS AND NAM LOOKS GOOD SATURDAY NIGHT. WIND
SHOULD DIMINISH LATE SATURDAY INTO SATURDAY NIGHT.
BOTH MET AND MAV GUIDANCE EXHIBITING TYPICAL HIGH BIAS IN DEW POINTS
IN A WELL-MIXED WEST TO NORTHWEST FLOW. WILL UNDERCUT THIS GUIDANCE
SATURDAY.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
MEDIUM RANGE MODELS ALL SIGNALING DEVELOPMENT OF HIGHLY AMPLIFIED
LONG WAVE TROUGH PATTERN ACROSS THE EASTERN U.S. AS THE GREENLAND
HIGH LOCKS IN WITH A STRONG NEGATIVE NAO SIGNAL. PRIOR TO THIS...A
COUPLE OF WEATHER SYSTEMS WILL PUSH ACROSS THE REGION WITH THE
POSSIBILITY OF MIXED WINTRY WEATHER MAINLY ACROSS INLAND AREAS. BY
THE MIDDLE OF NEXT WEEK...IT APPEARS THAT DRY BUT BLUSTERY AND VERY
COLD WEATHER WILL RETURN.
SUNDAY...MODELS CONTINUE TO PUSH HIGH PRES OFF THE MID ATLC
COAST...WHICH WILL FINALLY SHUT OFF THE COLD AIR AS WINDS BACK TO
S-SW. LOW PRES DEVELOPS OVER THE SE U.S. AND ANOTHER LOW MOVES
ACROSS CENTRAL CANADA. AN ASSOCIATED FRONT WILL APPROACH DURING THE
DAY...WITH INCREASING CLOUDS.
LOOKS LIKE THE MOISTURE AHEAD OF THIS SYSTEM QUICKLY WORKS E...SO
HAVE INCREASED POPS TO CHANCE FOR EASTERN AREAS AND LIKELY FOR THE
WEST BY LATE IN THE DAY. WITH THE INCREASING WARM AIR ADVECTION
PATTERN...EXPECT PRECIP TO START OFF AS MAINLY RAIN...THOUGH THERE
COULD BE SOME MIXING ACROSS THE HIGHER TERRAIN OF THE BERKSHIRES AND
MONADNOCKS. WITH THE ONSHORE FLOW AND WATER TEMPS STILL IN THE
LOWER-MID 40S...WILL BE HARD PRESSED TO SEE ANY MIXED PRECIP CLOSER
TO THE COAST.
SUNDAY NIGHT...GOOD MODEL AGREEMENT CONTINUES IN BRINGING SLUG OF
PRECIP ON PRETTY GOOD S-SE WINDS ACROSS THE REGION. KEPT CATEGORICAL
POPS GOING FOR MOST AREAS...EXCEPT HIGH LIKELY FOR AREAS NEAR AND N
OF ROUTE 2 AWAY FROM BEST MOISTURE CONVERGENCE.
BIG QUESTION AT THIS POINT WILL BE HOW FAR S THE MIX OR CHANGE OVER
TO SNOW WILL GET INTO THE REGION. TEMPS GENERALLY STAY IN THE UPPER
20S TO AROUND 30 ACROSS N CENTRAL/NW MA INTO S NH. HOWEVER...PARTIAL
THICKNESSES INDICATE A GENERAL MIX WITH RAIN AND SNOW /AND A FEW
PLACES MAY EVEN SEE A FEW PERIODS OF FREEZING RAIN...THOUGH NOT IN
THE FORECAST FOR NOW/. AT THIS POINT...THE MIX SHOULD HOLD SNOW
AMOUNTS DOWN BELOW ADVISORY LEVEL.
APPEARS PRECIP SHOULD START CUTTING OFF OVER THE CT VALLEY AFTER 06Z
OR SO...THOUGH LEFTOVER SNOW SHOWERS MAY LINGER. CLOSER TO THE
COAST...EXPECT TO SEE MAINLY RAIN...THOUGH MAY SEE A MIX WITH SNOW
TOWARD MORNING.
MONDAY...LOW AND FRONT CLEAR THE COAST BY 12Z...WITH LEFTOVER PRECIP
ACROSS EASTERN AREAS ENDING BY LATE MORNING. WILL SEE BRIEF PERIOD
OF PARTIAL SUNSHINE. NEXT SYSTEM ALREADY STARTS TO HEAD NE OUT OF
THE GREAT LAKES. THE LOW ITSELF WILL REMAIN WELL N OF THE REGION...
BUT ANOTHER FRONT WILL PUSH E. EXPECT CLOUDS TO RETURN DURING THE
AFTERNOON.
HAVE CHANCE POPS IN FOR MONDAY NIGHT. MORE MARGINAL TEMP PROFILE FOR
MIXED PRECIP WITH THIS SYSTEM...AS NOT QUITE AS MUCH WARM AIR
ADVECTION. MAY SEE MORE OF A WINTRY MIX ACROSS CENTRAL-W MA/S NH
WITH A MIX OF RAIN AND SNOW SHOWERS AS FAR S AS N CT AND NW RI.
SHOULD REMAIN MAINLY RAIN ALONG THE COAST.
TUESDAY...COLD FRONT WILL PUSH THROUGH LATE IN THE DAY...WITH ANY
MIXED PRECIP CHANGING TO RAIN EXCEPT OVER THE HIGHER TERRAIN WELL
INLAND. PRECIP WILL TAPER OFF LATE AFTERNOON AND EARLY EVENING FROM
W-E. COULD SEE A MIX WITH SNOW BEFORE ENDING ACROSS MOST AREAS AS
COLDER AIR WORKS IN.
WEDNESDAY THROUGH FRIDAY...WITH THE BLOCKING PATTERN SETTING UP
ACROSS NORTH AMERICA...EXPECT THE LOW TO STALL OVER THE CANADIAN
MARITIMES WHILE HIGH PRESSURE RIDGE BUILDS ACROSS THE CENTRAL U.S
INTO CENTRAL CANADA. THIS WILL ALLOW ARCTIC AIR TO PUMP INTO THE
REGION. MAY SEE LAKE EFFECT SNOW SHOWERS WORKING ACROSS NY STATE
AGAIN...DEPENDING UPON THE WIND DIRECTION ON WEDNESDAY.
EXPECT DRY BUT VERY COLD AND BLUSTERY CONDITIONS TO PREVAIL DURING
THIS TIMEFRAME. DAYTIME HIGHS WILL RUN ABOUT 5 TO 10 DEGREES BELOW
SEASONAL NORMS. OVERNIGHT LOWS FORECASTED TO DROP TO THE SINGLE
DIGITS AND TEENS. WITH STRONG WINDS...ESPECIALLY ON WEDNESDAY...
WILL SEE WIND CHILL READINGS DROP TO BELOW ZERO ACROSS THE HIGHER
TERRAIN AND THE SINGLE DIGITS ELSEWHERE BOTH WEDNESDAY AND THURSDAY
NIGHTS.
&&
.AVIATION /21Z FRIDAY THROUGH WEDNESDAY/...
VFR FOR MOST OF THIS PERIOD. ISOLD -SHSN COULD BRIEFLY RESULT IN
MVFR VSBY NORTH OF KBOS-KORH-KPSF.
OUTLOOK /SUNDAY THROUGH WEDNESDAY/...
SUNDAY...VFR TO START...LOWERING TO MVFR CIGS/VSBYS IN DEVELOPING
-RA WITH MIX OR ALL -SN GENERALLY ACROSS THE HIGHER TERRAIN OF N
CENTRAL/NW MA AND S NH.
SUNDAY NIGHT...MVFR CIGS/VSBYS IN LIGHT RAIN ALONG THE COAST AND
MIXED -RASN INLAND. MAY SEE PATCHY -FZRA WELL INLAND...MAINLY COLDER
VALLEYS.
MONDAY...MVFR CIGS/VSBYS IN -RA OR MIXED -RASN EARLY MORNING...THEN
QUICKLY IMPROVING TO VFR FROM W-E BY AROUND MIDDAY. AS FRONT AND LOW
PRES MOVE E. ANOTHER LOW APPROACHES FROM THE W...WITH CIGS/VSBYS
LOWERING AGAIN AT NIGHT.
TUESDAY...MVFR CIGS/VSBYS IN MIXED PRECIP OVER INTERIOR AND MAINLY
-RA ALONG THE ACROSS E MA/RI AS LOW PRES PASSES N OF THE REGION.
CONDITIONS SLOWLY IMPROVE FROM W-E AT NIGHT...BUT MAY SEE LINGERING
WIDELY SCT -SHSN ESPECIALLY OVER E SLOPES OF THE BERKSHIRES INTO SW
NH.
WEDNESDAY...MAINLY VFR. MAY SEE LOCAL MVFR VSBYS IN WIDELY SCT -SHSN
ACROSS E SLOPES OF BERKSHIRES INTO SW NH.
&&
.MARINE...
STILL EXPECTING GUSTY WINDS ACROSS THE WATERS TONIGHT INTO SATURDAY.
HAVE DROPPED THE GALE WARNING IN NARRAGANSETT BAY...WHERE THE NOAA
PORTS DATA INDICATE WINDS BELOW 34 KT FOR THE VAST MAJORITY OF THE
BAY. ELSEWHERE...WILL CONTINUE THE GALE WARNING INTO EARLY SATURDAY
MORNING. WITH A HIGH PRESSURE MOVING INTO THE MID ATLANTIC STATES
DURING THE DAY...ADJUSTED THE TIMING OF THE GALE WARNING. WILL LIKELY
NEED TO ISSUE SMALL CRAFT ADVISORIES ONCE THE GALE WARNINGS ARE DONE
FOR AT LEAST A PORTION OF SATURDAY. WINDS DIMINISH SATURDAY NIGHT...
BUT ROUGH SEAS SHOULD CONTINUE ACROSS THE OUTER COASTAL WATERS
THROUGH MOST OF SATURDAY NIGHT.
OUTLOOK /SUNDAY THROUGH WEDNESDAY/...
SUNDAY...WINDS SHIFT FROM SW-SE WITH APPROACH OF FRONT AND LOW
PRES. MAY SEE GUSTS TO 25 KT ON THE SOUTHERN WATERS LATE. SEAS 4
FEET OR LESS.
SUNDAY NIGHT...LOW PRES MOVING S OF NEW ENGLAND MAY BRING SEAS UP
TO 5 FEET ON THE SOUTHERN WATERS. MAY SEE SOME BRIEF GUSTS TO 25 KT
EARLY. WINDS WILL SHIFT FROM S-SE TO W LATE.
MONDAY...WINDS SHIFT TO N...WITH GUSTS POSSIBLY INCREASING TO 25 KT
MAINLY ON THE OPEN OUTER WATERS EARLY. SEAS MAY BUILD UP TO 5 FT ON
THE SOUTHERN OUTER WATERS DURING THE DAYLIGHT HOURS.
TUESDAY...WINDS BECOME S AGAIN AS NEXT LOW PASSES WELL N OF THE
WATERS AND ASSOCIATED FRONT PUSHES ACROSS AT NIGHT. WIND GUSTS UP
TO 25 KT EARLY...THEN SHIFT TO W AND INCREASE TO GALE FORCE AFTER
MIDNIGHT. SEAS BUILD UP TO 6-8 FT.
WEDNESDAY...GALE FORCE W WINDS CONTINUE WITH STRONG COLD AIR
ADVECTION ACROSS THE WATERS. GUSTS UP TO 40-45 KT POSSIBLE WELL
OFFSHORE. SEAS MAY BUILD UP TO 10 FEET ON THE EASTERN OUTER WATERS.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...GALE WARNING UNTIL 11 AM EST SATURDAY FOR ANZ231-232-250-
251-254>256.
GALE WARNING UNTIL 5 AM EST SATURDAY FOR ANZ230-233>235-237.
SMALL CRAFT ADVISORY UNTIL 1 PM EST SATURDAY FOR ANZ236.
&&
$$
SYNOPSIS...BELK/EVT
NEAR TERM...BELK
SHORT TERM...BELK
LONG TERM...EVT
AVIATION...BELK/EVT
MARINE...BELK/EVT
