AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
324 PM EST WED FEB 6 2013


.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
HIGHLIGHTS...

***WINTER STORM WATCH EXPANDED TO COVER THE ENTIRE REGION FRIDAY
INTO SATURDAY MORNING WITH PERHAPS A PERIOD OF BLIZZARD CONDITIONS
ALONG THE COASTAL PLAIN FOR A TIME FRIDAY NIGHT INTO SATURDAY
MORNING***

A QUICK UPDATE WAS SENT OUT TO EXPAND A WINTER STORM WATCH TO COVER
THE ENTIRE REGION. CONFIDENCE CONTINUES TO GROW IN A FOOT OR MORE
OF SNOW AFFECTING A LARGE PORTION OF THE REGION. WE HAVE BROUGHT UP
SNOW ACCUMULATIONS WITH THE LATEST FORECAST...BUT IT MAY NOT EVEN BE
ENOUGH IN SOME LOCALES. BIGGEST UNCERTAINTY IS NEAR THE SOUTH COAST
AND HOW FAR NORTH A TEMPORARY TRANSITION TO RAIN MAKES IT FRIDAY
AFTERNOON. HOWEVER...EVEN ON THE CAPE AND ISLANDS AREAS THAT CHANGE
TO RAIN MAY GET HIT HARD BY THE COLD CONVEYER BELT. NEAR BLIZZARD
CONDITIONS WILL BE POSSIBLE FRIDAY NIGHT INTO EARLY SATURDAY ACROSS
PORTIONS OF THE COASTAL PLAIN...AND TRAVEL MAY BECOME NEARLY
IMPOSSIBLE. WILL HAVE MUCH MORE LATER THIS AFTERNOON.

PREVIOUS DISCUSSION:

* POTENTIAL FOR A VERY SIGNIFICANT WINTER STORM FRI INTO EARLY SAT
* STRONG WINDS/COASTAL FLOODING ARE ALSO A CONCERN
* PLENTY OF UNCERTAINTY REMAINS IN THE EXACT DETAILS

DETAILS...

THURSDAY NIGHT INTO EARLY SATURDAY....
THERE IS THE POTENTIAL FOR A VERY SIGNIFICANT WINTER STORM LATE
THURSDAY NIGHT INTO EARLY SATURDAY. THE EXACT DETAILS REMAIN
UNCERTAIN...BUT CONFIDENCE HAS INCREASED ENOUGH TO GO WITH A
WINTER STORM WATCH FOR PORTIONS OF SOUTHERN NEW ENGLAND. THE
POTENTIAL IS CERTAINLY THERE FOR A FOOT OR MORE OF SNOW IN SOME
LOCATIONS...BUT A LOT OF THINGS NEED TO BE WORKED OUT.

MOST OF THE 06/00Z GUIDANCE HAS COME INTO BETTER AGREEMENT ON THE
GENERAL IDEA OF A WEAK LOW PRESSURE MOVING INTO THE GREAT LAKES
LATE THURSDAY NIGHT...WITH A MORE SIGNIFICANT LOW PRESSURE
DEVELOPING OFF THE MID ATLANTIC STATES AND MOVING NORTHEAST.
06/00Z ECMWF HAS DRAMATICALLY SLOWED THE TIMING OF ITS LOW
PRESSURE...RESULTING IN FAR MORE SIGNIFICANT STORM FOR OUR REGION.
GIVEN THIS SHIFT...LEANED AWAY FROM THE 00Z ECMWF AND FOLLOWED A
CONSENSUS SOLUTION WHICH INCLUDED THE 05/12Z ECMWF. THIS WAS TO
MINIMIZE THE TIMING DIFFERENCES AND TO SMOOTH OUT SOME OF THE
DETAILS IN THE FORECAST.

THE OVERRUNNING OF THE COLD DOME AT THE SURFACE SHOULD RESULT IN
SOME LIGHT SNOW DEVELOPING BY EARLY FRIDAY MORNING. LIGHT SNOW
WILL PROBABLY AFFECT MUCH OF THE AREA FRIDAY MORNING...BUT AMOUNTS
SHOULD BE RATHER LIGHT.

THE MAIN SHOW STILL LOOKS TO OCCUR FRIDAY AFTERNOON INTO EARLY
SATURDAY. THERE ALSO IS A STRONG HIGH PRESSURE OVER EASTERN
CANADA THAT WILL BE SUPPLYING THE COLD AIR. THIS IS A CLASSIC
SETUP FOR A MAJOR WINTER STORM ACROSS SOUTHERN NEW ENGLAND. THE
OTHER CONCERN WOULD BE FOR A PERIOD OF VERY STRONG WINDS ON THE
COAST WITH THE TIGHT PRESSURE GRADIENT. SOME TYPE OF WIND
HEADLINES WILL PROBABLY BE NEEDED.

THERE ARE TWO MAIN THINGS WE ARE A BIT CONCERNED WITH AT THIS
POINT...

THE FIRST AND PROBABLY THE BIGGEST CONCERN IS WILL THERE BE ANY
MIXING ALONG THE COASTAL PLAIN. GIVEN THE CURRENT POSITION OF THE
HIGH AND BOMBING LOW PRESSURE SYSTEM ON THE MODELS...ODDS FAVOR
MAINLY SNOW ACROSS MOST OF THE REGION. THERE COULD BE SOME ISSUES
FOR A TIME ALONG THE FAR SOUTHEAST NEW ENGLAND COAST ESPECIALLY
THE CAPE/ISLANDS. THAT IS THE SCENARIO THAT THE CURRENT MODELS ARE
ADVERTISING...BUT A 50 OR SO MILE SHIFT IN THE TRACK NORTHWEST
WILL MAKE A BIG DIFFERENCE. IF THIS WERE TO OCCUR...MIXING ISSUES
COULD AFFECT A LARGER PART OF THE COASTAL PLAIN SO SOMETHING WILL
HAVE TO WATCH CLOSELY GIVEN THAT WERE STILL 72+ HOURS OUT.

THE OTHER ISSUE IS HOW FAR INLAND DOES THE HEAVIEST PRECIPITATION
EXTEND. THE CURRENT MODELS INDICATE THAT THE POTENTIAL FOR
HEAVIEST SNOW WILL BE ALONG THE COASTAL PLAIN. GIVEN THE WELL
DEFINED MID LEVEL CENTERS AND LIKELY STRONG DEFORMATION ZONE WE
MAY SEE HEAVY SNOW AFFECT EVEN THE DISTANT INTERIOR. HOWEVER...ITS
POSSIBLE THAT THE MODEL TRACK COULD SHIFT EAST WHICH WOULD LIMIT
THE COVERAGE OF HEAVY SNOW THAT FAR WEST.

TO SUM UP...EVERYONE IN SOUTHERN NEW ENGLAND SHOULD BE PREPARED
FOR THE POTENTIAL OF A VERY SIGNIFICANT WINTER STORM FRIDAY INTO
EARLY SATURDAY. WHILE ITS TOO EARLY TO TRY TO PIN DOWN SPECIFIC
SNOWFALL AMOUNTS AND THEIR LOCATIONS...THE POTENTIAL IS THERE FOR
A FOOT OR MORE OF SNOW IN SOME LOCATIONS.