FXUS61 KBOX 251420
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
920 AM EST FRI DEC 25 2009
.SYNOPSIS...
MIDWEST LOW PRESSURE WILL REDEVELOP ALONG THE CAROLINAS AND MOVE UP
THE EASTERN SEABOARD THIS WEEKEND...BRINGING A PERIOD OF WINTRY
WEATHER INLAND WITH MAINLY RAIN ALONG THE COAST. THE LOW AND ITS
PRECIPITATION SHOULD DEPART SUNDAY AFTERNOON. WEAK LOW PRESSURE WILL
BRING A CHANCE OF LIGHT SNOW TO SOUTHERN AREAS ON MONDAY. VERY COLD
AND BLUSTERY WEATHER WILL FOLLOW IN THE WAKE OF THIS LOW MONDAY NIGHT
INTO WEDNESDAY. A COASTAL STORM MAY BRING MORE WINTRY PRECIPITATION
TO THE REGION AROUND NEW YEARS EVE.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HIGH PRESSURE CENTERED OVER QUEBEC EXTENDS INTO NEW ENGLAND. THIS
BRINGS A NORTHEAST MARINE FLOW INTO PARTS OF EASTERN MASS AND RI.
OVERCAST LOW CLOUDINESS HAS MOVED INLAND ACROSS EASTERN AND SOUTHEAST
MA FROM BEVERLY TO BOSTON TO TAUNTON AND NEW BEDFORD. WITH FLOW
BECOMING MORE NE DURING THE DAY...DO NOT SEE MUCH HOPE FOR THESE
BREAKING UP. ALSO...SCATTERED LOW CLOUDINESS HAS BEGUN TO DEVELOP
ELSEWHERE ACROSS SOUTHERN NEW ENGLAND. INCREASING/THICKENING CIRRUS THIS
AFTERNOON AS THE MIDWEST STORM AND ITS COASTAL PARTNER FEED
MOISTURE UP THE COAST. THIS MAY ALSO HELP TO LOCK IN THE LOW CLOUDS.
MAX TEMPS ARE A BLEND OF GFS AND NAM MOS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/...
QUESTION ON TONIGHTS FORECAST IS THE POTENTIAL FOR DRIZZLE/FREEZING
DRIZZLE AS THE INCREASING EASTERLY LOW LEVEL FLOW RUNS INTO THE
CENTRAL HILLS AND BERKSHIRES. MOST OF THIS LIFT WILL OCCUR IN AREAS
THAT SHOULD BE AT OR BELOW FREEZING...BUT WITH DRY AIR ABOVE
CONFINING PRECIPITATION GROWTH TO A SHALLOW LAYER. WILL MENTION
CHANCE OF FREEZING DRIZZLE IN THE INTERIOR TONIGHT.
OTHERWISE THE QUESTION FOR TONIGHT AND SATURDAY IS THE TIMING OF
PRECIP ONSET. ENOUGH DRY AIR AND LACK OF ISENTROPIC LIFT TONIGHT TO
MAKE PRECIP GENERATION A TOUGH SELL. WE WILL BRING CHANCE POPS INTO
THE REGION BETWEEN MIDNIGHT AND 6 AM SATURDAY WITH THE BEST CHANCE
REMAINING WEST OF KEENE-PROVIDENCE. BETTER LIFT AND SATURATION
ARRIVES IN THE CT VALLEY SATURDAY MORNING AND IN EASTERN SECTIONS
DURING THE AFTERNOON AND EVENING. WE WILL TIME THE ARRIVAL OF LIKELY
POPS TO THIS SCHEDULE WITH CATEGORICAL POPS IN THE WEST SATURDAY
AFTERNOON.
PRECIP TYPE WILL DEPEND ON THE ACTUAL TIME OF ONSET. TEMPERATURE
PROFILES LATER TONIGHT WOULD FAVOR SNOW OR ICE...WHILE PROFILES
SATURDAY AFTERNOON IN ALL BUT THE NORTHWEST WOULD FAVOR RAIN WITH A
LESSER CHANCE OF SNOW OR SLEET. WE USED THE NAM THERMAL PROFILES TO
GENERATE PRECIP TYPE. SURFACE TEMPERATURES COME FROM A BLEND OF MOS.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
SEEMS TO BE BETTER CONTINUITY WITH THE EARLY PORTION OF THE MEDIUM
RANGE MODEL SUITE THIS MORNING. MODELS TEND TO FINALLY WEAKEN THE
LOW AS IT MOVES OUT OF THE GREAT LAKES INTO NORTHERN NEW ENGLAND
THIS WEEKEND. MODELS ALSO CONTINUE TO SIGNAL ANOTHER SHOT OF ARCTIC
AIR MOVING INTO THE REGION EARLY NEXT WEEK...ALONG WITH ANOTHER SHOT
OF SNOW SHOWERS. MODEL SOLUTIONS DIVERGE BEYOND TUESDAY...MAINLY DUE
TO HOW THEY ARE HANDLING LOW PRESSURE THAT MAY PUSH INTO THE WEST
COAST.
SATURDAY NIGHT...WILL SEE SOME LEFTOVER MIXED SLEET OR WET SNOW
ACROSS THE HIGHER TERRAIN OF W AND N CENTRAL MA INTO S NH...BUT
EXPECT TEMPS TO RISE OVERNIGHT AS E-SE WINDS INCREASE TO SCOUR OUT
THE COLD AIR. ELSEWHERE...EXPECT A STEADY CHILLY RAIN. TEMPS WILL
EITHER REMAIN STEADY OR SLOWLY RISE OVERNIGHT WITH MILDER AIR
WORKING ASHORE MAINLY AFTER MIDNIGHT.
WITH GOOD SHOT OF LOW LEVEL MOISTURE CONVERGENCE MOVING INTO CENTRAL
AND SOUTHERN AREAS...WILL SEE PERIODS OF HEAVY RAINFALL. ALL DEPENDS
UPON HOW MUCH RAIN IS ABSORBED BY THE SNOWPACK...BUT WILL LIKELY SEE
AREAS OF POOR DRAINAGE AND URBAN FLOODING MAINLY DUE TO CATCH BASINS
BEING CLOGGED BY SNOW FROM THE STORM LAST WEEKEND. QPF COULD
APPROACH AN INCH ON AVERAGE...WITH SOME LOCAL HIGHER AMOUNTS.
SUNDAY...LOW PRES WILL MOVE ACROSS THE REGION DURING THE MORNING...
WITH RAIN MOVING NE DURING THE DAY. WILL SEE DRY SLOT WORKING INTO
THE REGION...WITH PRECIP ENDING ACROSS WESTERN AREAS BY MIDDAY...BUT
LEFTOVER RAIN MAY LINGER INTO THE AFTERNOON ACROSS E MA/RI. MAY BE
ENOUGH DRY AIR THAT WORKS IN TO ALLOW SOME SUN TO BREAK THROUGH
ACROSS N CT/SW MA DURING THE AFTERNOON. NOT A LOT OF COLD AIR BEHIND
THIS SYSTEM...SO TEMPS WILL BE MILD.
SUNDAY NIGHT...ANOTHER BATCH OF CLOUDS WORK ACROSS THE REGION AHEAD
OF ANOTHER APPROACHING SHORT WAVE. WILL BE COOLER...THOUGH STILL 5
TO 10 DEGREES ABOVE SEASONAL NORMS FOR LATE DECEMBER. TEMPS WILL
FALL BELOW FREEZING ACROSS MOST AREAS...SO COULD SEE SOME LOCAL
REFREEZING OF ANY STANDING WATER.
MONDAY-MONDAY NIGHT...ANOTHER SHORT WAVE WILL WORK ACROSS THE REGION
AND MAY EVEN SPIN UP A WEAK LOW S OF NEW ENGLAND. AN AREA OF LOW
LEVEL MOISTURE WILL ALSO MOVE E...SO HAVE CARRIED HIGH CHANCE POPS
FOR SNOW SHOWERS. DEPENDING UPON AMOUNT OF MOISTURE...COULD SEE SOME
LIGHT SNOW ACCUMULATIONS. AN ARCTIC FRONT WILL PUSH IN BEHIND THIS
MONDAY NIGHT.
TUESDAY-WEDNESDAY...EXPECT SKIES TO BE MAINLY CLEAR AS HIGH PRES
BUILDS W OF THE REGION...BUT WILL BE VERY WINDY AND COLD AS ANOTHER
SHOT OF ARCTIC AIR MOVES IN. EXPECT DAYTIME HIGHS ON TUESDAY TO RUN
10 TO 15 DEGREES BELOW NORMAL. COULD SEE OVERNIGHT LOWS NEAR OR
BELOW ZERO WELL INLAND TUESDAY NIGHT.
THURSDAY...APPEARS THE HIGH WILL HOLD LONG ENOUGH TO KEEP DRY
CONDITIONS WITH SLIGHTLY MODERATING TEMPERATURES.
MODELS SHOWING SOME CONSISTENCY IN ADVERTISING A COASTAL STORM THAT
MAY AFFECT THE REGION NEW YEARS EVE. WILL CONTINUE TO MONITOR THIS
POTENTIAL.
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
TODAY...
OVERCAST LOW CLOUDINESS HAS MOVED INLAND ACROSS EASTERN AND
SOUTHEAST MA FROM BEVERLY TO BOSTON TO TAUNTON AND NEW BEDFORD AS
WELL AS THE CAPE AND ISLANDS. WITH FLOW BECOMING MORE NE DURING THE
DAY...DO NOT SEE MUCH HOPE FOR THESE BREAKING UP. ALSO...SCATTERED
LOW CLOUDINESS HAS BEGUN TO DEVELOP ELSEWHERE ACROSS SOUTHERN NEW
ENGLAND. INCREASING/THICKENING CIRRUS THIS AFTERNOON AS THE MIDWEST
STORM AND ITS COASTAL PARTNER FEED MOISTURE UP THE COAST. THIS MAY
ALSO HELP TO LOCK IN THE LOW CLOUDS.
SO...SCATTERED AREAS OF IFR CIG THIS MORNING WITH IFR CIG AND VSBY
IN FOG FOR A FEW MORE HOURS AT BDL/BAF...BECOMING MVFR. IFR CIG AT ORH
AND MHT AS LOW CLOUDS DEVELOP AND PERSIST. MVFR CIG AT BOS/HYA/ACK/PVD
THROUGH THE DAY.
TONIGHT...
MEDIUM CONFIDENCE THAT INCREASING EAST FLOW SHOULD SATURATE LOW
LEVELS AND BRING MVFR CIGS. LOW CONFIDENCE THAT UPSLOPE FLOW OF THE
MOIST AIR MAY BRING FREEZING DRIZZLE TO INLAND AREAS SUCH AS ORH-MHT-
BAF-BDL. LOW CHANCE THAT MIXED PRECIP MAY ARRIVE IN THE CT VALLEY AND
SOUTHERN RI AFTER 06Z.
SATURDAY...MVFR CIGS IN THE MORNING. PRECIP MOVING UP THE COAST
SHOULD MOVE INTO THE REGION...EARLIEST IN CT AND LATEST ALONG THE
MASS EAST COAST. FLIGHT CONDITIONS SHOULD LOWER TO IFR IN THE
AFTERNOON/EVENING AS PRECIP BEGINS. LOW CONFIDENCE IN THE EXACT
TIMING...IT COULD BE SLOWER.
OUTLOOK...SATURDAY NIGHT THROUGH TUESDAY...
SATURDAY NIGHT...IFR CONDITIONS EXPECTED IN MAINLY RAIN...ALTHOUGH A
WINTRY MIX POSSIBLY AT KORH AND POSSIBLY KMHT EARLY.
SUNDAY...MVFR/IFR CONDITIONS IMPROVE TO VFR AROUND MIDDAY.
MONDAY...VFR. AREAS OF MVFR CIGS/VSBYS IN SNOW SHOWERS.
TUESDAY...VFR...GUSTY NW WINDS.
&&
.MARINE...
TODAY...
NORTHEAST WINDS GENERALLY 10 TO 15 KTS. SMALL CRAFT ADVISORY
CONTINUES ON THE OUTER WATERS FOR ROUGH SEAS.
TONIGHT...
EAST WINDS AND SEAS INCREASE DURING THE NIGHT WITH SMALL CRAFT
CONDITIONS EXPANDING CLOSER TO SHORE ESPECIALLY ON THE SOUTHERN
WATERS.
SATURDAY...
EAST WINDS AND SEAS CONTINUE TO INCREASE. WINDS MAY APPROACH GALE
FORCE LATE IN THE DAY ON THE WATERS SURROUNDING BLOCK ISLAND. WILL
ISSUE A GALE WATCH FOR THE VINEYARD-TO-MONTAUK OUTER
WATERS...THIS MAY EXPAND TO OTHER WATERS AS WE GET CLOSER.
OUTLOOK...SATURDAY NIGHT THROUGH TUESDAY...
SATURDAY NIGHT-SUNDAY...EAST TO SOUTHEAST WINDS WILL LIKELY REACH
GALE FORCE. SEAS COULD REACH 12-15 FEET ON THE OUTER WATERS.
MONDAY...SMALL CRAFT WINDS AND SEAS MAY REACH GALE FORCE AFTER
MIDNIGHT ON THE OUTER WATERS.
MONDAY NIGHT AND TUESDAY...NW WINDS MAY CONTINUE AT GALE FORCE.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 1 AM TO 4 PM EST SATURDAY FOR
ANZ230>237.
SMALL CRAFT ADVISORY UNTIL 4 PM EST SATURDAY FOR ANZ250-251-
254>256.
GALE WATCH FROM SATURDAY AFTERNOON THROUGH LATE SATURDAY NIGHT
FOR ANZ256.
&&
$$
SYNOPSIS...WTB/EVT
NEAR TERM...GAF
SHORT TERM...WTB
LONG TERM...EVT
AVIATION...GAF/EVT
MARINE...WTB/EVT
