FXUS61 KBOX 091736
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
1236 PM EST WED DEC 9 2009
.SYNOPSIS...
A STRONG STORM WILL AFFECT SOUTHERN NEW ENGLAND TODAY WITH A MIX OF
WINTRY PRECIPITATION AND A PERIOD OF STRONG WINDS AT THE COAST.
BLUSTERY AND CHILLY WEATHER WILL FOLLOW THURSDAY INTO EARLY NEXT
WEEK. A PERIOD OF RAIN AND OR SNOW SHOWERS MAY OCCUR TUESDAY IN
ASSOCIATION WITH LOW PRESSURE.
&&
.NEAR TERM /UNTIL 10 PM THIS EVENING/...
*** A PERIOD OF HEAVY SNOW FOR MUCH OF SOUTHERN NEW ENGLAND THIS
MORNING FOLLOWED BY STRONG TO DAMAGING WINDS AT THE COAST ***
PNS AND LSRS CONT TO BE ISSUED WRAPPING UP SNOW THE NEXT FEW HOURS
AND ADDING WIND.
13MB 3 HRLY FALLS NR 44018 AT NOON. 41G58KT AT WELLFLEET MESONET...
HIT 55 KT AT ELEVATED HORSESHOE AT 1151AM.
SNOW TRANSITIONING TO RAIN IN RTE 2 REGION.
AT 1PM WILL CONVERT TO WXA NRN MA AND S NH.
HEAVIEST QPF ENDING EARLY AFTN BUT SNOWMELT CONTRIBUTING TO PONDING
ON STREETS AND SPS IS POSTED.
NO MAJOR CHANGES TO THE CF AND WIND STATEMENTS ATTM.
STILL TREE LIMB DAMAGE OCCURRING IN PREVIOUS HEAVY WET SNOW REGION OF
SE MA WHERE GUSTY WINDS ADD TO THE WEIGHTED LIMB STRESS.
&&
.SHORT TERM /10 PM THIS EVENING THROUGH THURSDAY NIGHT/...
TONIGHT...LEFTOVER SNOW AND RAIN SHOWERS WITH CYCLONIC FLOW
PREVAILING BEHIND A DEPARTING CANADIAN MARITIMES LOW. TURNING WINDY
AND COOL. A WIND ADVISORY MAY STILL BE NECESSARY PARTICULARLY THE
CAPE AND ISLANDS WHERE SW WINDS COULD GUST TO 45 KT.
THURSDAY AND THURSDAY NIGHT...A TROUGH WILL CROSS THE AREA DURING THE
LATE AFTERNOON OR EVENING. THIS WILL BRING MUCH COLDER AIR TO THE
REGION. MOISTURE IS FAIRLY LIMITED...BUT COULD SEE SCATTERED SNOW
SHOWERS OR FLURRIES PARTICULARLY THE INTERIOR HIGH TERRAIN WHERE SOME
LAKE MOISTURE WILL BE AVAILABLE. LOW LEVEL LAPSE RATES WILL BE
STEEPENING ALONG THE SOUTH COAST. OCEAN EFFECT SNOW SHOWERS WILL BE
POSSIBLE NEAR NANTUCKET AND MARTHAS VINEYARD AS WEST FLOW PREVAILS.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
THE MID TO LONG RANGE MODELS AND THE ENSEMBLES ARE FAIRLY GOOD
AGREEMENT REGARDING THE MEAN SYNOPTIC SCALE FLOW THROUGH EARLY
SATURDAY...THEN BEGIN TO DIVERGE DAYS 5 THROUGH 7. THE
TELECONNECTIONS CONTINUE TO FAVOR A NEGATIVE NAO PATTERN WITH THE
PNA BECOMING POSITIVE. THIS GENERALLY FAVORS COLDER THAN NORMAL
TEMPERATURES ACROSS THE AREA DURING THE EXTENDED TIMEFRAME.
FRIDAY...BLUSTERY CONDITIONS...A COLD WESTERLY FLOW PREVAILS WITH AS
1000-500MB THICKNESSES DROP DOWN INTO THE 510S! DIURNAL CLOUDS AND
SCATTERED SNOW SHOWERS AND FLURRIES WILL BE POSSIBLE DUE TO CYCLONIC
FLOW AT H85 AND ALOFT WHICH WILL TRANSPORT SOME LAKE MOISTURE INTO
THE REGION. WIND CHILL VALUES WILL BE IN THE TEENS.
SATURDAY...HIGH PRESSURE BUILDS ACROSS THE AREA...A DRY DAY EXPECTED
BUT TEMPERATURES REMAIN COLDER THAN NORMAL.
SUNDAY THROUGH TUESDAY...QUESTIONS REMAIN WHETHER THE POLAR JET
CONTINUES TO SUPPRESS MOISTURE SOUTH OF THE REGION EARLY NEXT WEEK.
APPEARS THAT BRIEF RIDGING SHOULD OCCUR SUNDAY BEFORE THE NEXT COLD
FRONT APPROACHES BY MONDAY OR TUESDAY. GENERALLY FOLLOWED HPC.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
REST OF TODAY...
THE SNOW TO RAIN TRANSITION AREA CONTINUES TO ADVANCE NORTHWARD. IT WAS
LOCATED NEAR OR JUST SOUTH OF THE MA PIKE AS OF 10 AM. TO THE SOUTH
OF THIS REGION..CONDITIONS LIFR CONDITIONS HAVE IMPROVED TO IFR.
THERE WERE EVEN AREAS OF LOW END MVFR DEVELOPING. TO THE NORTH OF
THE PIKE...LIFR/VLIFR CONDITIONS WERE STILL OCCURRING IN MODERATE TO
HEAVY SNOW.
THE TRANSITION FROM SNOW TO RAIN SHOULD CONTINUE TO ADVANCE
NORTHWARD LATE THIS MORNING AND EARLY AFTERNOON. ALL TERMINALS
EXCEPT MHT SHOULD HAVE TRANSITIONED TO RAIN BY NOON. A BRIEF PERIOD
OF SLEET/LIGHT FREEZING RAIN IS ALSO POSSIBLE. OTHERWISE...EXPECT
THE HEAVY SNOW TO TRANSITION TO RAIN AT MHT BY EARLY TO MID
AFTERNOON. LIFR/VLIFR CONDITIONS SHOULD IMPROVE TO IFR WITH EVEN
POCKETS OF LOW END MVFR.
KBOS TAF SITE IS IFR TO LOW END MVFR FOR THE REMAINDER OF THE
AFTERNOON. NO ADDITIONAL SNOW OR ICE WILL OCCUR.
OUTLOOK /TONIGHT THROUGH SUNDAY/...
TONIGHT THROUGH SUNDAY...VFR CONDITIONS. LOCAL MVFR IN -SHSN NEAR
THE BERKS THU PM THROUGH FRI PM. W WINDS GUSTING UP TO 35 TO 40 KT
AT TIMES THURSDAY THROUGH FRIDAY...PARTICULARLY ALONG THE SOUTH
COAST. WINDS DIMINISHING BY LATE SATURDAY. MECHANICAL WIND
SHEAR/TURBULENCE.
&&
.MARINE...
TODAY...
COASTAL LOW WILL PASS VICINITY OF CAPE COD CANAL THIS AFTERNOON
ACCOMPANIED BY A PERIOD OF EASTERLY STORM FORCE WINDS ACROSS
NANTUCKET AND CAPE COD WATERS. EASTERLY GALES ELSEWHERE.
OUTLOOK /TONIGHT THROUGH SUNDAY/...
TONIGHT THROUGH SATURDAY...HIGH PROBABILITY OF GALES THROUGH SATURDAY
AS EXCELLENT WIND MOMENTUM TRANSFER WILL CONTINUE DUE TO STRONG COLD
AIR ADVECTION OVER THE RELATIVELY WARM ATLANTIC WATERS. SHOULD SEE
GUSTS TO 35 TO 45 KT THROUGH SATURDAY...DIMINISHING TO SMALL CRAFT
BY LATE SATURDAY OR EARLY SUNDAY.
&&
.HYDROLOGY...
PRECIPITATION TOTALS /MOSTLY RAIN/ OF 1 TO 1.5 INCHES ARE POSSIBLE
ACROSS CT/RI AND SOUTHEAST MA AFTER THE CHANGEOVER FROM SNOW. WHILE THIS
MAY RESULT IN URBAN AND POOR DRAINAGE FLOODING...ESPECIALLY NEAR S
COAST...MAINSTEM RIVERS ARE EXPECTED TO REMAIN WITHIN THEIR BANKS.
PAWTUXET IN RI AT CRANSTON WILL BE MONITORED BUT EXPECTED TO REMAIN
BELOW FS.
&&
.TIDES/COASTAL FLOODING...
AT 11AM...
NANTUCKET RUNNING .4 BLO THE 12Z MRPSSE
BOSTON 0.9 ABV THE PREDICTED SURGE.
PVD 1.3 ABV THE 12Z VSN OF THE MRPSSE SURGE AND WE EXPECT PVD TO REACH
AT LEAST 7.5 EARLY THIS AFTN.
COASTAL FLOOD ADVISORY CONTINUES AS IS.
AT 9AM...
NANTUCKET 0.2 ABV PREDICTED SURGE FROM 06Z GFS MRPSSE
BOSTON 0.7 ABOVE
PROVIDENCE 1 FT
THIS REINFORCES THE LIKELIHOOD OF TIDAL INUNDATION PBLMS AT HIGH TIDE
UPPER NARR BAY AND NE COASTAL MASS THIS AFTN. 40-41 KNOTS OF WIND AT JFK
BDR AT 9 AM... AND WILL GROW WORSE ENHANCING RISK OF HIGH WAVES NE
MASS COAST. SEAS AT 9AM 7 FT NE MASS COAST BUT WILL GROW TIL AT LEAST
13 FT BY NIGHT...POSSIBLY 17 FT. AT 44025 WE SEE SEAS UP TO 15 FT NOW
AND 51 KT AT THE TEXAS TOWER BUOY 066.
SE GRADIENT RAISES RISK OF MINOR COASTAL FLOODING ALONG MAINLY SE
FACING COASTLINES DURING THIS AFTERNOON HIGH TIDE. ETSS OUTPUT GIVES
ABOUT 1.5 FT ALONG THE MA E FACING COAST AND 2 TO 3 FT ALONG THE S
FACING COASTS OF RI AND BUZZARDS BAY. RECOGNIZING THAT THE SURGE FROM
THE ETSS TENDS TO BE CONSERVATIVE...WE HAVE ADDED A FEW TENTHS TO
HALF A FOOT TO THE MODEL VALUES. THE STRONGEST GRADIENT LOOKS TO
COINCIDE CLOSELY WITH THE TIME OF HIGH TIDE ALONG BOTH THE S COAST
AND E COAST OF MA...EVEN THOUGH THE HIGH TIDE TIMES THEMSELVES ARE
DIFFERENT.
WAVES OF 10 TO 15 FT NOT TOO FAR OFFSHORE WILL YIELD A SPLASH OVER
RISK ALONG THE EXPOSED COASTLINES. UPPER NARRAGANSETT BAY COULD GET
CLOSE TO MODERATE...SO A CHANCE THAT THE ADVISORY MAY HAVE TO BE
UPGRADED THERE. ONE SPECIAL CASE IS PROVINCETOWN HARBOR. WOULD NOT
EXPECT A SE WIND TO GENERATE MUCH SURGE THERE BUT ONCE THE WIND
SHIFTS TO SSW...THEN COULD SEE A SUDDEN SURGE OF PERHAPS 1.5 FEET OR
SO AND AN ONSHORE WIND FOR SPLASH OVER ALONG THE HARBOR FRONT.
ALSO HEAVY RAIN LATE THIS MORNING AND INTO THE AFTERNOON MAY
EXACERBATE FLOODING IN THE UPPER PART OF NARRAGANSETT BAY /PROVIDENCE/
AND BOSTON HARBOR.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...WINTER STORM WARNING UNTIL 1 PM EST THIS AFTERNOON FOR
MAZ002>006-008>012-014-026.
WIND ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR MAZ007-015-016-
018>021.
COASTAL FLOOD ADVISORY UNTIL 7 PM EST THIS EVENING FOR MAZ007-
014>016-019-022.
HIGH WIND WARNING UNTIL 3 PM EST THIS AFTERNOON FOR MAZ022>024.
COASTAL FLOOD ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR
MAZ020-021.
NH...WINTER STORM WARNING UNTIL 1 PM EST THIS AFTERNOON FOR NHZ011-
012-015.
RI...WIND ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR RIZ006>008.
COASTAL FLOOD ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR
RIZ002-004>007.
MARINE...STORM WARNING UNTIL 5 PM EST THIS AFTERNOON FOR ANZ231-232-250-
254-255.
GALE WARNING UNTIL 5 PM EST THIS AFTERNOON FOR ANZ230-233>237-
251-256.
&&
$$
SYNOPSIS...DRAG/STRAUSS
NEAR TERM...DRAG/NOCERA 1235P
SHORT TERM...STRAUSS
LONG TERM...STRAUSS
AVIATION...NOCERA/FRANK/STRAUSS 1235P
MARINE...DRAG/NOCERA/STRAUSS 1235P
HYDROLOGY...
TIDES/COASTAL FLOODING...
