River Flood Warning 81, NWS Boston/Norton, MA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
1145 AM EST TUE DEC 14 2010

.SYNOPSIS...
TEMPERATURES WILL REMAIN WELL BELOW NORMAL THROUGH THURSDAY BEFORE
MODERATING TO NEAR NORMAL FRIDAY AND INTO THE WEEKEND. THERE IS A
LOW PROBABILITY FOR A WINTER STORM TO IMPACT THE REGION SATURDAY
NIGHT AND/OR SUNDAY...BUT THE STORM COULD JUST AS EASILY PASS
HARMLESSLY OUT TO SEA.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HAVE UPDATED THE GRIDS AND ZONES TO REFLECT CURRENT CONDITIONS. AS
WINDS HAVE BECOME MORE W-NW...THE AREA OF SNOW SHOWERS THAT HAD
WORKED INTO S COASTAL AREAS PUSHED OFFSHORE BY LATE MORNING.  CLOUDS
ALSO BREAKING UP QUITE NICELY ACROSS MOST AREAS EXCEPT THE CAPE AND
ISLANDS AS WELL AS NEAR THE BERKSHIRES AND SW NH.  ALSO NOTE THIN
STREAMERS ACROSS E NY OFF LAKE ONTARIO. RATHER THIN...SO EXPECT NO
MORE THAN ISOLATED SNOW SHOWERS ACROSS THE E SLOPES OF THE
BERKSHIRES. ALSO MAY STILL SEE A COUPLE MORE QUICK SNOW SHOWERS
ELSEWHERE THROUGH MIDDAY...BUT EXPECTED TO END.

ALSO NOTED THAT TEMPS AND DEWPTS WERE RUNNING AT LEAST A FEW DEGREES
BELOW THE FORECAST...SO ADJUSTED THESE. NOT EXPECTING MUCH MORE OF A
RISE IN TEMPS WITH THE CONTINUED STRONG COLD AIR ADVECTION MOVING
ACROSS THE REGION...SO ADJUSTED MAX TEMPS DOWNWARD JUST A BIT
CONSIDERING THIS.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM WEDNESDAY/...
TONIGHT...PLENTY OF CLOUD COVER WILL NOT PREVENT TEMPERATURES FROM
FALLING SHARPLY OVERNIGHT. MANY LOCATIONS IN CENTRAL
MASSACHUSETTS... SOUTHWEST NEW HAMPSHIRE AND NORTHERN CONNECTICUT
WILL SEE TEMPS IN THE LOWER TEENS AND SOME AREAS IN THE SINGLE
DIGITS. SUB ZERO WIND CHILL VALUES ARE POSSIBLE TONIGHT AS WINDS
ARE NOT EXPECTED TO GO CALM AND BREEZY CONDITIONS OVERNIGHT WILL
DEFINITELY ADD A BITE TO THE BELOW NORMAL COLD TEMPERATURES
EXPECTED TONIGHT.

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
HIGHLIGHTS...
  * A RETURN TO COLD WEATHER WITH BELOW NORMAL TEMPS MUCH OF THIS
    PERIOD
  * LOW PROBABILITY OF A WINTER STORM SAT NIGHT AND/OR SUNDAY

MODEL PREFERENCES...
MODELS FAIRLY CLOSE AT THE BEGINNING OF THIS PERIOD /12Z WED/ BUT
THEN BEGIN TO DIVERGE ON HOW VORTEX OVER THE NORTHEAST WILL
INTERACT WITH UPSTREAM VORTEX OVER WESTERN CANADA AS NORTHEAST
VORTEX RETROGRADES. THIS IMPACTS THE FLOW EVOLUTION ACROSS THE
NORTHERN TIER OF THE U.S. AND INTO NEW ENGLAND ESPECIALLY THIS
WEEKEND WHEN THERE IS GOOD MODEL AGREEMENT ON CYCLOGENESIS
ALONG/OFF THE EASTERN SEABOARD.

00Z GFS/GEFS/ECMWF AND GGEM ARE IN GOOD AGREEMENT WITH AN OFFSHORE
TRACK AS THESE MODELS PLACE POLAR VORTEX AND MEAN MID LEVEL TROF
AXIS TOO FAR EAST FOR A CLOSER STORM TRACK. INTERESTINGLY THE
UKMET CONTINUES TO BE MOST ROBUST AND WEST WITH A 972 MB LOW JUST
EAST OF CAPE ANN SUN EVENING! HPC INFORMS US /PREEPD/ THAT THE
12Z/13 ECMWF ENSEMBLE MEAN IS CLOSER TO THE COAST THAN MODEL
CONSENSUS. THEREFORE THE CHANCE POPS FROM THE GFS MOS SAT NGT INTO
SUN SEEM REASONABLE. THUS THE HIGHEST RISK FOR AN ACCUMULATING
SNOW CONTINUES TO APPEAR TO BE CAPE COD AND ISLANDS.

DAILIES...
ANOMALOUS RIDGE OVER GREENLAND AND THE DAVIS STRAIT /-NAO/ WILL
PROMOTE POLAR VORTEX TO RESIDE ACROSS SOUTHEAST CANADA AND
NORTHERN NEW ENGLAND. THIS WILL SUPPORT BELOW NORMAL HEIGHTS AND
TEMPS ACROSS THE REGION THROUGHOUT THIS FORECAST PERIOD.

 WED AND THU... PROBABLY COLDEST DAYS OF THE WEEK WITH 850 TEMPS
-13C TO -16C. GUSTY WNW WIND WED WILL PROVIDE COLD WIND CHILL
VALUES. MAINLY DRY WEATHER IS EXPECTED HOWEVER CAN/T RULE OUT AN
ISOLATED/BRIEF SNOW SHOWER AT ANY TIME WITH LAKE EFFECT SNOWS
POSSIBLY SPILLING OVER THE BERKSHIRES AND LITCHFIELD HILLS.
ADDITIONAL SNOW SHOWERS POSSIBLE WED NGT INTO THU MORNING AS
POTENT SHORT WAVE PINWHEELS AROUND VORTEX INTO SOUTHERN NEW
ENGLAND. MOISTURE IS LIMITED SO ANY SNOW ACCUMULATION SHOULD BE
MINOR.

FRI/SAT... DRY AND COLD WEATHER CONTINUES WITH POLAR VORTEX OVER
SOUTHERN QUEBEC.

SAT NIGHT AND SUN...
AS MENTIONED ABOVE WE WILL CONTINUE CHANCE POPS FOR SNOW
/ESPECIALLY ACROSS SOUTHEAST MA/ AS ALL MODEL GUIDANCE SUGGEST
CYCLOGENESIS SOMEWHERE ALONG OR OFF THE EAST COAST. POSITION OF
POLAR VORTEX AND THE ASSOCIATED MEAN MID LEVEL TROF AXIS OVER THE
NORTHEAST WILL BE CRITICAL IN DETERMINING THE STORM TRACK. STAY
TUNED.

MON...
SHOULD SEE SOME IMPROVEMENT WITH STORM MOVING SEAWARD BUT COLD
WEATHER WILL LIKELY PREVAIL.

TEMPS WERE DERIVED FROM MAVMOS AND THE COLDER IN HOUSE BIAS
CORRECTED GFS MOS.

&&

.AVIATION /16Z TUESDAY THROUGH SATURDAY/...
THROUGH THIS AFTERNOON...MODERATE TO HIGH CONFIDENCE FOR VFR CIGS
AND VSBYS. WILL SEE LOCAL MVFR CIGS/VSBYS IN ANY LEFTOVER SNOW
SHOWERS THROUGH 18Z.

TONIGHT...MODERATE CONFIDENCE FOR VFR CIGS/VSBYS.

KBOS TERMINAL...HIGH CONFIDENCE IN TAF. EXPECT VFR CIGS THROUGH
TONIGHT.

OUTLOOK...WEDNESDAY THROUGH SATURDAY...
HIGH CONFIDENCE IN VFR CONDITIONS THE VAST MAJORITY OF THE TIME.  WE
MAY SEE SOME BRIEF MVFR CONDITIONS IN STRATO-CUMULUS CLOUDS ALONG
WITH A PASSING FLURRY/SNOW SHOWER OR TWO WEDNESDAY/THURSDAY.  THE
STRONGEST WINDS LOOK TO BE ON WEDNESDAY WITH WEST TO NORTHWEST WIND
GUSTS OF 20 TO 35 KNOTS EXPECTED DURING THE DAY.

&&

.MARINE...
THIS AFTERNOON AND TONIGHT...SMALL CRAFT ADVISORY CONDITIONS WILL
CONTINUE. MAY SEE A FEW GUSTS NEAR GALE FORCE IN THE WATERS SOUTH OF
NEW ENGLAND LATE TONIGHT. SEAS WILL REMAIN WELL ABOVE 5 FEET OUTSIDE
OF SHELTERED HARBORS/SOUNDS. STILL NOTING SEAS UP TO 15-20 FEET WELL
S AND E OF NANTUCKET AT MIDDAY.

OUTLOOK...WEDNESDAY THROUGH SATURDAY...
WNW WINDS OF 15-20 KT WITH GUSTS TO 25 KT POSSIBLE WED AND THU BUT
THEN DIMINISH FRI AND SAT. COULD HAVE A GALE CENTER DEVELOP AND
TRACK OVER EASTERN GEORGES BANK SOMETIME THIS WEEKEND. LIGHT FREEZING
SPRAY POSSIBLE BOTH WED AND THU.

&&

.HYDROLOGY...
THE CONNECTICUT RIVER AT HARTFORD AND MIDDLETOWN MAY SLIGHTLY EXCEED
THEIR MINOR FLOOD STAGES WEDNESDAY. AS THE UPSTREAM CONTRIBUTIONS
FROM THE TRIBUTARIES STILL BEING ROUTED TO THE MAINSTEM...AND THE
RIVER ONLY EXPECTED TO SLIGHTLY EXCEED FLOOD STAGE. WILL HOLD OFF ON
ISSUING WARNING AT THIS POINT. ADDITIONAL GUIDANCE WILL BE AVAILABLE
LATER TODAY WHICH WILL HELP TO DEFINE THE NEED FOR ANY ACTION FOR
THE MAINSTEM CT RIVER.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 AM EST WEDNESDAY FOR
     ANZ232>234.
     SMALL CRAFT ADVISORY UNTIL 6 PM EST WEDNESDAY FOR ANZ235-
     237-250-251-254>256.

&&

SYNOPSIS...NOCERA/MANNING
NEAR TERM...EVT
SHORT TERM...MANNING
LONG TERM...NOCERA
AVIATION...NOCERA/MANNING/EVT
MARINE...NOCERA/EVT
HYDROLOGY...MANNING

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE TAUNTON MA
427 AM EST TUE DEC 14 2010

CTZ002>004-MAZ002>024-026-NHZ011-012-015-RIZ001>008-150930-
HARTFORD CT-TOLLAND CT-WINDHAM CT-WESTERN FRANKLIN MA-
EASTERN FRANKLIN MA-NORTHERN WORCESTER MA-CENTRAL MIDDLESEX MA-
WESTERN ESSEX MA-EASTERN ESSEX MA-WESTERN HAMPSHIRE MA-
WESTERN HAMPDEN MA-EASTERN HAMPSHIRE MA-EASTERN HAMPDEN MA-
SOUTHERN WORCESTER MA-WESTERN NORFOLK MA-SOUTHEAST MIDDLESEX MA-
SUFFOLK MA-EASTERN NORFOLK MA-NORTHERN BRISTOL MA-
WESTERN PLYMOUTH MA-EASTERN PLYMOUTH MA-SOUTHERN BRISTOL MA-
SOUTHERN PLYMOUTH MA-BARNSTABLE MA-DUKES MA-NANTUCKET MA-
NORTHERN MIDDLESEX MA-CHESHIRE NH-EASTERN HILLSBOROUGH NH-
WESTERN AND CENTRAL HILLSBOROUGH NH-NORTHWEST PROVIDENCE RI-
SOUTHEAST PROVIDENCE RI-WESTERN KENT RI-EASTERN KENT RI-BRISTOL RI-
WASHINGTON RI-NEWPORT RI-BLOCK ISLAND RI-
427 AM EST TUE DEC 14 2010

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHERN
CONNECTICUT...CENTRAL MASSACHUSETTS...EASTERN
MASSACHUSETTS...NORTHEASTERN MASSACHUSETTS...SOUTHEASTERN
MASSACHUSETTS...WESTERN MASSACHUSETTS...SOUTHERN NEW
HAMPSHIRE...NORTHERN RHODE ISLAND AND SOUTHERN RHODE ISLAND.

.DAY ONE...TODAY AND TONIGHT.

SOME SLIPPERY ROADS ARE POSSIBLE ACROSS THE CONNECTICUT RIVER
VALLEY WHERE PERIODS OF LIGHT SNOW OCCURRED OVERNIGHT INTO EARLY
THIS MORNING.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY.

THERE IS THE POSSIBILITY THAT THE CONNECTICUT RIVER AT MIDDLETOWN
GOES INTO MINOR FLOOD WEDNESDAY. IN ADDITION...THE CONNECTICUT RIVER AT
HARTFORD MAY APPROACH FLOOD STAGE WEDNESDAY.

THERE IS THE POTENTIAL THAT A WINTER STORM AFFECTS SOUTHERN NEW
ENGLAND SOMETIME SATURDAY NIGHT AND/OR SUNDAY.
HOWEVER...CONFIDENCE IS LOW AND THE STORM COULD JUST AS EASILY PASS
HARMLESSLY OUT TO SEA.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

ANZ230>237-250-251-254>256-150930-
BOSTON HARBOR-CAPE COD BAY-NANTUCKET SOUND-VINEYARD SOUND-
BUZZARDS BAY-RHODE ISLAND SOUND-NARRAGANSETT BAY-BLOCK ISLAND SOUND-
COASTAL WATERS EAST OF IPSWICH BAY AND THE STELLWAGEN BANK NATIONAL
MARINE SANCTUARY-MASSACHUSETTS BAY AND IPSWICH BAY-
COASTAL WATERS FROM PROVINCETOWN MA TO CHATHAM MA TO NANTUCKET MA
OUT 20 NM-
COASTAL WATERS EXTENDING OUT TO 25 NM SOUTH OF MARTHAS VINEYARD AND
NANTUCKET-
COASTAL WATERS FROM MONTAUK NY TO MARTHAS VINEYARD EXTENDING OUT TO
20 NM SOUTH OF BLOCK ISLAND-
427 AM EST TUE DEC 14 2010

THIS HAZARDOUS WEATHER OUTLOOK IS FOR MASSACHUSETTS COASTAL WATERS
AND RHODE ISLAND COASTAL WATERS.

.DAY ONE...TODAY AND TONIGHT.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY.

THERE IS A LOW TO MODERATE PROBABILITY FOR A PERIOD OF GALE FORCE WIND
GUSTS ACROSS THE SOUTHERN WATERS WEDNESDAY AND/OR WEDNESDAY NIGHT.

THERE ALSO IS A MEDIUM PROBABILITY FOR A PERIOD OF GALE FORCE WIND
GUSTS SATURDAY NIGHT AND/OR SUNDAY IF A LOW PRESSURE SYSTEM TRACKS
CLOSE ENOUGH TO THE COAST.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.