FXUS61 KBOX 261015
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
515 AM EST SAT DEC 26 2009
.SYNOPSIS...
LOW PRESSURE OVER THE CAROLINAS WILL MOVE UP THE ATLANTIC COAST
BRINGING A MIXTURE OF PRECIPITATION TO SOUTHERN NEW ENGLAND THIS
MORNING AND MAINLY RAIN LATE TODAY INTO EARLY SUNDAY. ANOTHER WEAK
LOW PRESSURE SYSTEM WILL LIKELY BRING SOME LIGHT SNOW TO THE REGION
LATE SUNDAY NIGHT AND 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
NEW YEARS EVE OR NEW YEARS DAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MEASURABLE PRECIP MOVED INTO CT AND WESTERN MASS OVERNIGHT WITH
ADDITIONAL AREAS OF PRECIP LINED DOWN THE COAST. PRECIP TYPES RANGED
FROM SNOW IN THE CT VALLEY TO RAIN AND FREEZING RAIN IN SOUTHEAST
CT. PER BOX RADAR THIS LEADING AREA OF PRECIP IS SHRINKING AS IT
MOVES NORTHEAST...SO LESS OF A CHANCE FOR IT TO AFFECT EASTERN
SECTIONS. THOSE EASTERN SECTIONS ARE INSTEAD AFFECTED BY ONSHORE
CONVEYOR BRINGING LIGHT SNOW AND DRIZZLE. THIS SHOULD CONTINUE
THROUGH THE MORNING. WHERE TEMPS ARE BELOW FREEZING THE DRIZZLE IS
ACTUALLY FREEZING DRIZZLE...AND COULD CAUSE TRAVEL PROBLEMS ON
UNTREATED SURFACES. WITH ALL OF THIS IN MIND...WE ARE KEEPING THE
WINTER WEATHER ADVISORY IN PLACE FOR THE INTERIOR THROUGH MIDDAY.
ADDITIONAL AREAS OF PRECIP MOVING UP THE COAST WILL MOVE INTO THE CT
VALLEY AND OTHER WESTERN SECTIONS DURING THE MORNING AND WORK EAST
BY EVENING. WITH THIS IN MIND WE TREND POPS UP THROUGH THE DAY WITH
ALL BUT EXTREME EASTERN SECTIONS AT CATEGORICAL POPS /FOR
MEASURABLE PRECIP/ BY 6 PM.
MAX AND MET MOS TEMPERATURES WERE SIMILAR...SO GRID TEMPS ARE A
BLEND OF MOS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
NON DIURNAL TEMPERATURE TRACE FORECAST FOR SATURDAY NIGHT...WITH
TEMPERATURES RISING THROUGH THE 30S IN THE NORTHWEST AND TO NEAR 50
IN SOUTHEAST MASS. THIS WILL FAVOR RAIN MUCH OF THE NIGHT...SOME SNOW
MAY LINGER IN THIS HILLS DURING THE EVENING. IT WILL BECOME RATHER
WINDY NEAR THE COAST SAT NIGHT BUT THE STRONGEST WINDS SHOULD BE
CONFINED TO THE COASTAL WATERS.
LOW PRESSURE WILL CROSS NEW ENGLAND SUNDAY. WE TIMED THE END OF
CATEGORICAL AND LIKELY POPS TO THE WIND SHIFT FROM EASTERLY TO
WESTERLY. ENOUGH OF A DRY SLOT MOVING IN WITH THE WIND SHIFT TO FAVOR
AT LEAST PARTIAL CLEARING DURING THE AFTERNOON. TEMPS ALOFT FAVOR MAX
TEMPS IN THE 40S...MAYBE 50 IN THE SOUTHEAST WHERE SUCH TEMPS WILL
HAVE BEEN ADVECTED IN.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
MEDIUM RANGE MODELS SHOWING DECENT CONSISTENCY THROUGH THE EARLY
PORTION OF THE LONG TERM...BUT HAVING MAJOR TIMING AND CONTINUITY
ISSUES BEYOND WEDNESDAY ESPECIALLY WITH THE ECMWF. THIS COULD HAVE
MAJOR IMPLICATIONS WITH THE POSSIBILITY OF STORMY WEATHER EITHER NEW
YEARS EVE AND/OR NEW YEARS DAY.
SUNDAY NIGHT-MONDAY...STRONG SHORT WAVE STILL PROGGED TO MOVE ACROSS
THE REGION. EXPECT LIGHT SNOW TO DEVELOP AS A WEAK WAVE MAY EVEN
FORM AND CROSS THE REGION LATE MONDAY...AS SOME MODEL RUNS HAVE
SHOWN THIS. SHOULD SEE AN INCH OR TWO OF SNOW FROM THIS SYSTEM...BUT
COULD HAVE A FEW LOCALLY HIGHER AMOUNTS IF THE ATLANTIC IS TAPPED A
BIT. HAVE CARRIED LIKELY POPS FOR MOST AREAS BY MIDDAY MONDAY...BUT
SHOULD PUSH OFFSHORE RATHER QUICKLY WITH A 50 KT H85 JET
APPROACHING. TEMPS ALONG S COASTAL MA AND COASTAL RI MAY BE WARM
ENOUGH TO ALLOW A MIX WITH OR CHANGE TO RAIN.
MONDAY NIGHT...NEXT SHORT WAVE MOVES ACROSS THE REGION...WITH ITS
ASSOCIATED ARCTIC SURFACE FRONT. VERY STRONG LAPSE RATES AS MODELS
CONTINUE TO DROP H85 TEMPS DOWN TO -23C TO -26C INTO NORTHERN NEW
ENGLAND BY 12Z TUESDAY...BUT APPEARS THAT MOST OF THE MOISTURE WILL
BE CARRIED OFF WITH THE EARLIER SYSTEM. HOWEVER...WITH SUCH A STRONG
UPPER LEVEL SYSTEM...WOULD NOT BE SURPRISED TO SEE SOME SNOW SQUALLS
WITH THE FRONTAL PASSAGE. W-NW WINDS WILL START TO ROAR AS THE COLD
AIR RUSHES IN.
TUESDAY-WEDNESDAY...HIGH PRES WILL BUILD ACROSS THE CENTRAL
U.S...BUT WILL REMAIN IN STRONG NW FLOW WITH ARCTIC AIR AND STRONG
W-NW WINDS. DAYTIME HIGHS TUESDAY WILL STRUGGLE TO BREAK 30...AND
MAY REMAIN BELOW 20 ACROSS THE HIGHER TERRAIN. WIND CHILL READINGS
WILL FALL BELOW ZERO ESPECIALLY ACROSS THE HIGHER TERRAIN INTO
CENTRAL AND WESTERN MASSACHUSETTS EVEN DURING THE DAY TUESDAY. LOOKS
LIKE MOST AREAS WILL SEE WIND CHILLS BELOW ZERO TUESDAY NIGHT...AND
AROUND -10 ACROSS THE HIGHER TERRAIN INTO S NH. WINDS WILL DIMINISH
ON WEDNESDAY AS THE CENTER OF THE HIGH APPROACHES...AND WILL ALLOW
TEMPS TO SLOWLY MODERATE.
THURSDAY-FRIDAY...BIG QUESTIONS AT THIS TIMEFRAME...WITH THE
POSSIBILITY OF A STORM WORKING OUT OF THE SOUTHERN STREAM UP THE
EASTERN SEABOARD EITHER NEW YEARS EVE AND/OR NEW YEARS DAY. MODELS
HAVING MAJOR TIMING AND CONTINUITY ISSUES...SO CONTINUE TO HAVE ONLY
LOW CONFIDENCE THAT ANYTHING WILL OCCUR.
&&
.AVIATION /10Z SATURDAY THROUGH WEDNESDAY/...
TODAY...OBSERVED MVFR CIGS AND VSBYS OVER THE REGION EARLY MORNING
WITH IFR CIGS/VSBYS UPSTREAM. MEDIUM TO HIGH CONFIDENCE IN MVFR
CONDITIONS THIS MORNING. HIGH CONFIDENCE THAT CONDITIONS WILL LOWER
TO IFR/LIFR LATER THIS AFTERNOON AS THE MAIN AREA OF PRECIP WORKS
NORTHWARD. LOW CONFIDENCE IN THE EXACT TIMING OF THIS TRANSITION.
MIXED PRECIP WILL CONTINUE THROUGH MID MORNING...ESPECIALLY BDL-BAF-
ORH-MHT. WARMING TEMPS THROUGH THE DAY SHOULD CHANGE PRECIP TO RAIN
FROM SOUTH TO NORTH WITH ALMOST ALL AREAS IN RAIN TOWARD SUNSET.
TONIGHT...HIGH CONFIDENCE FOR IFR CIGS AND VSBYS IN RAIN. INCREASING
EAST TO SOUTHEAST WINDS WILL INCREASE OVER THE CAPE AND ISLANDS...AND
POSSIBLY SOUTHEAST MASS...WITH 25 TO 35 KNOT GUSTS POSSIBLE. WINDS
WILL BE EVEN STRONGER AROUND 2000 FEET...SOUTHEASTERS OF 55 TO 60
KNOTS ARE FORECAST. MEDIUM CONFIDENCE OF LOW LEVEL WIND SHEAR FROM
BOS-PVD ACROSS THE CAPE AND ISLANDS.
SUNDAY...MVFR/IFR CONDITIONS IMPROVE TO VFR BY MIDDAY IF NOT SOONER.
WINDS DIMINISHING AND SHIFTING TO WEST BY MIDDAY.
OUTLOOK...SUNDAY NIGHT THROUGH WEDNESDAY...
SUNDAY NIGHT...VFR TO START...THEN MAY LOWER TO MVFR CIGS AFTER
MIDNIGHT ACROSS CT VALLEY INTO SW NH. CHANCE OF MVFR VSBYS IN LOCAL
-SN.
MONDAY...MVFR CONDITIONS POSSIBLE IN LIGHT SNOW...ESPECIALLY ALONG
AND SOUTH OF THE MASS PIKE.
MONDAY NIGHT...LOCAL MVFR CIGS/VSBY POSSIBLE ACROSS E MA EARLY...
OTHERWISE VFR WITH GUSTY NW WINDS.
TUESDAY...VFR. NW WIND GUSTS UP TO 30-35 KT POSSIBLE ALONG THE COAST
AND ACROSS THE HIGHER TERRAIN.
WEDNESDAY...VFR WITH DIMINISHING WINDS.
&&
.MARINE...
TODAY...INCREASING PRESSURE GRADIENT AS HIGH PRESSURE REMAINS OVER
THE MARITIMES AND LOW PRESSURE MOVES UP THE COAST. EAST WINDS WILL
INCREASE THROUGH THE DAY WITH GALE FORCE GUSTS IN THE SOUTHERN OUTER
WATERS TOWARD SUNSET.
TONIGHT...WINDS AND SEAS CONTINUE TO BUILD THROUGH THE NIGHT WITH
GALE FORCE GUSTS ALL AREAS EXCEPT BOSTON HARBOR AND NARRAGANSETT BAY.
WITH THIS EXPECTATION WE HAVE ISSUED GALE WARNINGS FOR ALL WATERS
EXCEPT THESE TWO...SMALL CRAFT ADVISORIES CONTINUE FOR BOSTON AND
NARRAGANSETT.
SUNDAY...GALE FORCE SOUTHEASTERLIES WILL QUICKLY DIMINISH DURING THE
MORNING HOURS WITH WINDS SHIFTING TO WEST BY THE AFTERNOON.
HOWEVER...SEAS WILL REMAIN HIGH...SO SMALL CRAFT ADVISORIES WILL BE
NEEDED SUNDAY AFTER THE GALES COME DOWN.
OUTLOOK...SUNDAY NIGHT THROUGH WEDNESDAY...
SUNDAY NIGHT...SMALL CRAFT CONDITIONS LIKELY.
MONDAY...WINDS MAY BRIEFLY DIMINISH BELOW SMALL CRAFT PRIOR TO THE
PASSAGE OF AN ARCTIC FRONT. W-NW WINDS MAY GUST TO 30 KT LATE IN THE
DAY.
MONDAY NIGHT THROUGH TUESDAY NIGHT...W-NW GALES LIKELY. STRONGEST
WINDS WILL PROBABLY OCCUR LATE MONDAY NIGHT AND TUESDAY.
WEDNESDAY...WINDS DIMINISH TO SMALL CRAFT.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR CTZ002>004.
MA...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR MAZ002>006-
008>013-026.
NH...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR NHZ011-012-
015.
RI...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR RIZ001-003.
MARINE...GALE WARNING FROM 4 PM THIS AFTERNOON TO 6 AM EST SUNDAY
FOR ANZ231>235-237-250-251-254>256.
SMALL CRAFT ADVISORY UNTIL 6 AM EST SUNDAY FOR ANZ230-236.
&&
$$
SYNOPSIS...WTB/EVT
NEAR TERM...WTB
SHORT TERM...WTB
LONG TERM...EVT
AVIATION...WTB/EVT
MARINE...WTB/EVT
