FXUS61 KBOX 011029
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
529 AM EST TUE DEC 1 2009
.SYNOPSIS...
HIGH PRESSURE WILL BRING DRY WEATHER AND NEAR SEASONABLE TEMPERATURES
TO SOUTHERN NEW ENGLAND TODAY THROUGH WEDNESDAY. A STRONG LOW
PRESSURE SYSTEM WILL BRING STRONG WINDS AND RAIN TO THE REGION LATE
WEDNESDAY NIGHT AND THURSDAY MORNING. AT OR BELOW NORMAL TEMPERATURES
WILL FOLLOW FRIDAY THROUGH THE WEEKEND AND THERE IS EVEN THE CHANCE
FOR SOME SNOW LATE SATURDAY/SATURDAY NIGHT IF LOW PRESSURE COMES
CLOSE ENOUGH TO THE COAST.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
COLD FRONT CONTINUES TO MOVE WELL OFFSHORE EARLY THIS MORNING.
COOLER...DRIER AND FAIR WEATHER IS BEING USHERED INTO SNE IN THE WAKE
OF THIS FRONT. SKIES WILL BE PARTLY TO MOSTLY SUNNY THIS
MORNING...HOWEVER A SHORT WAVE TROF QUICKLY APPROACHING FROM THE WEST
SHOULD ALLOW FOR THE RETURN OF MOSTLY CLOUDY SKIES TODAY...ESPECIALLY
ACROSS THE INTERIOR. MORE SUN WILL BE SEEN ON THE COASTAL PLAIN. THIS
DISTURBANCE WON/T HAVE MUCH MOISTURE TO WORK WITH...BUT ENOUGH ASCENT
MAY BE GENERATED TO ALLOW FOR A BRIEF RAIN/SNOW SHOWER ACROSS THE
HIGHER TERRAIN OF THE FAR INTERIOR THIS AFTERNOON. MAX TEMPERATURES
WERE DERIVED FROM A BLEND OF THE MAVMOS GUIDANCE AND THE NAM 2M
TEMPERATURES. THIS RESULTS IN HIGHS AROUND OR SLIGHTLY BELOW NORMAL
FOR TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
SHORT WAVE WILL WEAKEN AND LIFT TO THE NORTHEAST TONIGHT AND WILL
ALLOW FOR CLEARING AND COLDER CONDITIONS.
SURFACE HIGH PRESSURE CONTINUES TO SLIDE TO THE EAST OF NEW ENGLAND
ON WEDNESDAY AS LOW PRESSURE APPROACHES FROM THE SOUTHWEST. WE THINK
IT WILL REMAIN DRY THROUGHOUT THE DAY...WITH A SIGHT CHANCE THAT
PRECIP COULD GET INTO SOUTHWESTERNMOST ZONES VERY LATE IN THE DAY.
WE SIDED WITH THE SLIGHTLY SLOWER SOLUTIONS WHICH SHOULD ALLOW ANY
MEASURABLE PRECIPITATION TO ARRIVE AFTER DARK. OTHERWISE...EXPECT A
THICKENING CANOPY OF CIRRUS CLOUDS AS THE DAY...ESPECIALLY THE
AFTERNOON...PROGRESSES. TEMPERATURES SHOULD MAX OUT 5 TO POSSIBLY AS
MUCH AS 10 DEGREES ABOVE NORMAL IN PLACES.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
PREVIOUS DISCUSSION...
WEDNESDAY NIGHT AND THURSDAY...
CONFIDENCE IS HIGH THAT A STRONG LOW PRESSURE SYSTEM WILL TAKE AN
INLAND TRACK AND IMPACT SOUTHERN NEW ENGLAND LATE WEDNESDAY NIGHT
AND THURSDAY MORNING. THE LOW IS EXPECTED TO MOVE THROUGH WESTERN
OR CENTRAL NEW YORK STATE...DEPENDING ON WHICH MODEL ONE BELIEVES.
THERE ARE TWO MAIN THREATS WITH THIS SYSTEM...A PERIOD OF VERY STRONG
AND POTENTIALLY DAMAGING SOUTH TO SOUTHWEST WIND GUSTS AS WELL AS
THE POSSIBILITY OF COASTAL FLOODING ALONG THE SOUTH COAST DURING THE
TIME OF HIGH TIDE THURSDAY MORNING. IN ADDITION...A PERIOD OF HEAVY
RAIN IS EXPECTED WITH EVEN A FEW THUNDERSTORMS ALSO POSSIBLE. MORE
SPECIFICALLY...
1) WIND POTENTIAL...
ALL MODELS CONTINUE TO INDICATE AN INTENSIFYING LOW PRESSURE SYSTEM
PASSING WELL WEST OF SOUTHERN NEW ENGLAND. THE GFS IS STRONGEST BUT
ALL OTHER MODELS ARE STRONG ENOUGH. EXPECT SOMEWHERE AROUND A 985 TO
990 MB LOW TO TRACK ACROSS WESTERN OR CENTRAL NEW YORK LATE WED NIGHT
AND THU MORNING. THE 00Z GFS HAD 85 KNOTS AT 850 MB AND THE 06Z RUN
HAS COME DOWN TO 80 KNOTS...OR NEAR 90 MPH. THE 00Z NAM...WHILE NOT
AS DEEP WITH THE LOW PRESSURE AS THE GFS...ACTUALLY HAD A SMALL
BULLSEYE OF 90 KNOTS... OR NEAR 100 MPH... AT 3200 FT OVER
SOUTHERNMOST NEW ENGLAND AROUND DAYBREAK THU. THIS IS PROBABLY TOO
EXAGGERATED. ALL MODELS SHOW 70 KNOTS AT 925 MB. IN ADDITION...PRESSURE
FALLS OF 3 TO 5 MB IN 3 HOURS ARE EXPECTED. TEMPERATURES ARE
FORECAST TO SOAR OVERNIGHT...REACHING 60 DEGREES IN SOUTHEAST MA AND
RI BY DAYBREAK THU. UPON SUNRISE...THEY WILL RISE INTO THE MID 60S
AND HELP PROMOTE VERY GOOD MIXING TO THE SURFACE. ALTHOUGH SURFACE
WINDS MAY GUST TO 30-40 MPH ESPECIALLY ALONG THE COAST WED
NIGHT...BUFKIT PROFILES FOR BOTH THE NAM AND GFS SHOW THE STRONGEST
WINDS OCCURRING WITH MIXING ALONG AND AFTER THE FRONTAL PASSAGE.
THE UPSHOT...EXPECT SOLID WIND ADVISORY CRITERIA...WHICH IS SUSTAINED
WINDS 31-39 MPH OR GUSTS 46-57 MPH...OVER A LARGE PORTION OF THE AREA
BEGINNING ON THE SOUTH COAST WED NIGHT BEFORE DAYBREAK AND
OVERSPREADING MOST OF THE REGION THU ESPECIALLY BETWEEN 10 AM AND
3 PM ON SOUTHWEST WINDS BEHIND THE FRONT. WIND ADVISORY LEVEL WINDS
CAN CAUSE SCATTERED POWER OUTAGES AND FALLING TREE LIMBS. THERE IS A
CHANCE OF REACHING HIGH WIND WARNING CRITERIA...WITH SUSTAINED WINDS
40 MPH OR GREATER AND A FEW GUSTS TO 58 MPH OR HIGHER. AT THESE
LEVELS...THERE IS THE POTENTIAL FOR MORE WIDESPREAD POWER OUTAGES AND
DOWNED TREES. THE MOST LIKELY AREAS FOR THIS TO OCCUR WOULD BE FROM
PLYMOUTH TO FALL RIVER...AS WELL AS ON THE CAPE AND ISLANDS. A HIGH
WIND WATCH MAY BE NEEDED FOR PARTS OF THE AREA IN LATER FORECAST
PACKAGES.
2) MODERATE COASTAL FLOOD POTENTIAL ON THE SOUTH COAST THURSDAY
MORNING...
THE HIGHEST ASTRONOMICAL TIDES OF DECEMBER WILL BE OCCURRING ON
THURSDAY MORNING TO BEGIN WITH. IN ADDITION...THE STRONG WINDS MENTIONED
ABOVE MAY COINCIDE WITH THE ASTRONOMICAL HIGH TIDE...WHICH ROUGHLY
OCCURS AROUND 8 OR 9 AM IN THE MORNING ON THE SOUTH COAST. THE EXACT
TIMING WILL HAVE A HUGE IMPACT ON COASTAL FLOOD POTENTIAL. THERE IS A
CHANCE THAT THE STRONGEST WINDS WILL OCCUR JUST AFTER THE HIGH TIDE.
HOWEVER...THE POTENTIAL EXISTS FOR A 2 FOOT OR HIGHER STORM SURGE AT
THE TIME OF ASTRONOMICAL HIGH TIDE ALONG THE SOUTH COAST. THIS WILL
BRING THE POTENTIAL FOR MODERATE COASTAL FLOODING ESPECIALLY ACROSS
BUZZARDS AND NARRAGANSETT BAYS. MODERATE COASTAL FLOODING MEANS THAT
THERE IS THE POTENTIAL FOR STRUCTURAL DAMAGE TO VULNERABLE AREAS.
A COASTAL FLOOD WATCH MAY BE NEEDED IN SUBSEQUENT FORECAST PACKAGES.
3) HEAVY RAIN AND A FEW THUNDERSTORMS... STRONG FORCING AND DYNAMICS
WILL YIELD A PERIOD OF HEAVY RAIN SHOWERS...ESPECIALLY WITH GOOD
MOISTURE RETURN AND DEW POINTS REACHING WELL INTO THE 50S TO NEAR 60.
FORTUNATELY...THE SYSTEM IS A FAST MOVER SO WE ARE ONLY EXPECTING A
QUICK 1.00 TO 1.50 INCHES WITH PERHAPS SOME LOCALLY HIGHER AMOUNTS.
NO SIGNIFICANT SMALL STREAM OR RIVER FLOODING IS EXPECTED...BUT WE
WILL LIKELY SEE TYPICAL URBAN AND POOR DRAINAGE STREET FLOODING. IN
ADDITION...A STRONG LOW LEVEL JET AND MARGINAL INSTABILITY MAY YIELD
SCATTERED THUNDERSTORMS FOR A FEW HOURS LATE WED NIGHT OR EARLY
THURSDAY MORNING...NOT THE USUAL TIME FOR THUNDER.
ALL INDICATIONS ARE THAT SKIES WILL BREAK OUT INTO SUNSHINE THURSDAY
AFTERNOON.
FRIDAY THROUGH MONDAY...
ALL THE MODELS ARE IN GENERAL AGREEMENT IN UPPER LEVEL TROUGH
ESTABLISHING ITSELF OVER THE OHIO VALLEY AND EVENTUALLY THE NORTHEAST.
THIS WILL BE A PATTERN SHIFT COMPARED TO THE RELATIVELY MILD WEATHER
THAT WE HAVE SEEN FOR THE PAST MONTH. EXPECT TEMPERATURES TO AVERAGE
AT OR BELOW NORMAL THROUGH THE PERIOD.
THE MAIN WEATHER ISSUE WILL BE THE POTENTIAL FOR A SIGNIFICANT
COASTAL STORM LATE SATURDAY INTO SUNDAY. THE 00Z GFS HAD A DEEPENING
LOW PRESSURE SYSTEM OUT TO SEA BUT CLOSE ENOUGH TO GIVE THE CAPE AND
EASTERN SECTIONS OF SOUTHERN NEW ENGLAND SOME RAIN...CHANGING TO SNOW.
THE ECMWF MODEL WAS MUCH FARTHER TO THE SOUTHEAST...ALLOWING SOUTHERN
NEW ENGLAND TO ESCAPE ANY PRECIPITATION. AS A RESULT...HAVE
CONTINUED THE CURRENT FORECAST WITH CHANCE POPS.
IT SHOULD BE NOTED THAT THE 06Z GFS HAS NOW CREATED A MAJOR NOREASTER
OVER THE BENCHMARK WHICH WOULD MEAN A LOT OF SNOW FOR PORTIONS OF
SOUTHERN NEW ENGLAND. THIS IS A LONG WAY OUT IN THE FUTURE AND MODEL
SOLUTIONS ARE BOUND TO CHANGE QUITE A BIT. THE EVOLUTION OF THIS
SYSTEM IS HIGHLY DEPENDENT ON THE PHASING OF TWO AREAS OF VORTICITY...
ONE THAT IS FORECAST TO DIVE INTO THE TEXAS PANHANDLE AND THE OTHER
EMANATING FROM THE CENTRAL GULF OF MEXICO.
&&
.AVIATION /10Z TUESDAY THROUGH SATURDAY/...
TODAY...VFR AFTER A FEW PATCHES OF EARLY MORNING MVFR CIGS.
TONIGHT AND WEDNESDAY...VFR.
OUTLOOK /WEDNESDAY NIGHT THROUGH SATURDAY/...
WEDNESDAY NIGHT AND THURSDAY...A SIGNIFICANT STORM WILL BRING
MVFR-IFR CONDITIONS LATE WEDNESDAY NIGHT/THURSDAY MORNING IN HEAVY
RAIN...STRONG SOUTH TO SOUTHWEST WIND GUSTS TO 45 KT...ALONG WITH
SCATTERED THUNDERSTORMS.
THURSDAY NIGHT AND FRIDAY...MAINLY VFR CONDITIONS EXPECTED.
SATURDAY...LOW CONFIDENCE BUT MVFR-IFR CONDITIONS ARE POSSIBLE IN A
PERIOD OF SNOW.
&&
.MARINE...
TODAY AND TONIGHT...MAINLY MARGINAL SCA SEAS EXPECTED TODAY FOR THE
OUTER WATERS. WINDS MAY MARGINALLY GUST TO SCA LEVELS THIS MORNING
AND AGAIN THIS EVENING...BUT AGAIN IT LOOKS MARGINAL.
WEDNESDAY...HIGH PRESSURE RIDGING SHOULD BRING SUB-SCA CONDITIONS TO
ALL WATERS.
OUTLOOK /WEDNESDAY NIGHT THROUGH SATURDAY/...
WEDNESDAY NIGHT AND THURSDAY...CONFIDENCE IS HIGH THAT A STRONG LOW
PRESSURE SYSTEM WILL PASS WELL TO THE WEST OF THE REGION LATE
WEDNESDAY NIGHT AND THURSDAY MORNING. A PERIOD OF SOUTHERLY GALE
FORCE WINDS ARE EXPECTED ALONG WITH RAPIDLY BUILDING SEAS TO BETWEEEN
10 AND 15 FEET OVER THE SOUTHERN OUTER-WATERS. THERE IS A LOW
PROBABILITY OF STORM FORCE WIND GUSTS FOR AN HOUR OR TWO. A GALE
WATCH WILL LIKELY BE ISSUED LATER TODAY.
FRIDAY...WINDS SHOULD DIMINISH BELOW SCA CRITERIA BUT SEAS WILL
REMAIN ABOVE SCA THRESHOLDS ACROSS THE SOUTHERN OUTER-WATERS.
SATURDAY...THE POTENTIAL EXISTS FOR GALE FORCE NORTHEAST WINDS
AS LOW PRESSURE DEVELOPS OFF THE COAST. CONFIDENCE IS LOW TO MEDIUM
AT THIS TIME AS TO HOW FAR OFFSHORE THE STORM MIGHT BE.
&&
.CLIMATE...
BOSTON/S LOGAN AIRPORT HAS NOT FALLEN TO THE FREEZING MARK SO FAR
THIS SEASON. THE RECORD LATEST IN THE SEASON THAT BOSTON HAS
RECORDED ITS FIRST 32F WAS DEC 2ND 1975. AVERAGE FIRST DATE OF 32 IN
BOSTON IS AROUND NOVEMBER 4TH.
DESPITE THE POTENTIAL LATEST OCCURRING FREEZING TEMP AT BOSTON...WE
DID ESTABLISH THE 3RD EARLIEST MINOR SNOWFALL AT LOGAN AIRPORT THIS
FALL ON OCTOBER 18TH.
NOVEMBER 2009 WAS TOP 10 WARMEST AT OUR 4 CLIMATE SITES. BELOW ARE
PRELIMINARY NOVEMBER TEMPERATURE AVERAGES AND DEPARTURES FOR THE
MONTH.
BOS 48.8...PLUS 3.9...RANKED NUMBER 6.
BDL 46.4...PLUS 4.6...RANKED NUMBER 6.
PVD 48.9...PLUS 5.1...RANKED NUMBER 3.
ORH 44.5...PLUS 4.9...RANKED NUMBER 5.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EST THIS MORNING FOR ANZ231-
232-235-237-251.
SMALL CRAFT ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR ANZ250.
SMALL CRAFT ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR
ANZ254>256.
&&
$$
SYNOPSIS...EKSTER/FIELD
NEAR TERM...EKSTER
SHORT TERM...EKSTER
LONG TERM...FIELD
AVIATION...EKSTER/FIELD
MARINE...EKSTER/GAF
CLIMATE...STAFF
