Evening Taunton AFD

000
FXUS61 KBOX 282051
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
351 PM EST WED FEB 28 2007

.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...

MAIN FORECAST CHALLENGE IN THE SHORT TERM PERIOD REVOLVES AROUND 
PRECIP TYPE AND INTENSITY FOR THURSDAY NIGHT.

IN THE MEANTIME...FOR TONIGHT...EXPECT MOSTLY CLEAR SKIES. TOOK A 
BLEND OF THE MOS VALUES FOR MINS. INCREASING CLOUDS ARE EXPECTED ON 
THURSDAY AS A LOW PRESSURE SYSTEM APPROACHES FROM THE WEST. EXPECT 
HIGHS NEAR NORMAL DURING THE DAY THURS.

WARM AIR ADVECTION REALLY GETS CRANKING THURSDAY EVENING AS A STRONG 
SOUTHERLY LOW LEVEL JET DEVELOPS IN ADVANCE OF APPROACHING SHORT 
WAVE TROF. THIS WILL RESULT IN PRECIPITATION QUICKLY OVERSPREADING 
SOUTHERN NEW ENGLAND. IT WILL DEVELOP FIRST IN THE WESTERN ZONES 
EARLY IN THE EVENING...THEN PROGRESS EASTWARD TO THE FAR EASTERN 
SECTIONS OF THE CWA BY MIDNIGHT. THE PRECIPITATION WILL BECOME HEAVY 
AT TIMES OWING TO VERY STRONG ISENTROPIC UPGLIDE IN THE 285K TO 300K 
LAYER.

THE QUESTION THEN BECOMES PRECIPITATION TYPE. GIVEN THE STRENGTH OF 
THE LOW LEVEL JET AND THE LOW AND MID LEVEL TROF AXIS REMAINING TO 
THE WEST...THINKING THAT LOCATIONS ROUGHLY ALONG AND SOUTH OF ROUTE 
2 WILL EXPERIENCE A FAIRLY BRIEF PERIOD OF SNOW THURSDAY 
NIGHT...WHICH WILL QUICKLY CHANGE TO A MIXTURE OF SNOW/SLEET/RAIN 
AND POSSIBLY FREEZING RAIN BEFORE RUSH HOUR FRIDAY MORNING. NOT 
EXPECTING MUCH IN THE WAY OF SNOW ACCUMULATION IN THESE 
AREAS...PERHAPS A QUICK 1 TO 2 INCHES SOUTH OF THE MASS PIKE AND 2 
TO 4 INCHES BETWEEN THE MASS PIKE AND ROUTE 2. ALONG AND SOUTH OF 
I-95...INCLUDING NORTHERN CT...EXPECT VERY LITTLE IN THE WAY OF SNOW 
ACCUMULATIONS AS CHANGEOVER TO SLEET/RAIN SHOULD OCCUR QUITE QUICKLY.

FOR NORTHWESTERN MASS...INCLUDING SOUTHERN NEW HAMPSHIRE...WE FEEL 
THAT 3 TO 6 INCHES OF SNOW WILL BE POSSIBLE BEFORE A CHANGEOVER TO 
SLEET AND FREEZING RAIN OCCURS. HOWEVER...BECAUSE OF THE COMBINATION 
OF SNOW...SLEET...AND FREEZING RAIN THAT IS FORECAST TO OCCUR ON TOP 
OF THE 3 TO 6 INCHES OF SNOW DURING THE RUSH HOUR FRIDAY 
MORNING...HAVE OPTED TO GO WITH A WINTER STORM WATCH FOR THURSDAY 
NIGHT THROUGH NOON FRIDAY. HAVE INCLUDED THE FOLLOWING COUNTIES OR 
PORTIONS OF COUNTIES IN MASSACHUSETTS: EXTREME NORTHWEST 
MIDDLESEX...NORTHERN WORCESTER...FRANKLIN...HAMPSHIRE. IN SOUTHERN 
NEW HAMPSHIRE...ALL OF HILLSBOROUGH AND ALL OF CHESHIRE. 
&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
FRIDAY...
A MIX OF SNOW/SLEET AND FREEZING RAIN ACROSS NORTHWEST MA AND 
SOUTHWEST NH WILL BE WINDING DOWN AROUND MIDDAY...AS DRY SLOT MOVES 
ACROSS THE AREA FROM WEST TO EAST. FARTHER SOUTH...MAIN CONCERN WILL 
BE HEAVY RAIN POTENTIAL AS STRONG LOW LEVEL JET COMBINES WITH DEEP 
LAYER MOISTURE WITH PWS CLIMBING TO +1.0.   

GFS IS FARTHER S WITH AXIS OF HEAVY RAIN...WHICH IS CENTERED ALONG 
SOUTH COAST...WITH NAM FARTHER N ACRS CT/RI AND MUCH OF MA ALONG AND 
SOUTH OF THE MASS PIKE. GGEM FARTHER NORTHWEST LIKE THE NAM. A LOT 
OF CENTERS AROUND THE TRACK OF SURFACE LOW AND ITS ASSOCIATED 
CONVERGENCE FIELD AND LOW LEVEL MOISTURE/THERMAL ADVECTION. GIVEN 
TRACK OF MID LEVEL DYNAMICS TRACK WELL NORTHWEST OF THE 
REGION...THINK SURFACE LOW AND QPF WILL TRACK FARTHER NORTHWEST 
ACROSS CT/RI AND MUCH OF MA PER THE NAM AND GGEM.  THIS SURFACE LOW 
TRACK WILL ALSO PROVIDE SOME OROGRAPHIC ENHANCEMENT TO THE QPF 
ACROSS HILLY TERRAIN OF CT AND MA.   

LATER SHIFTS WILL HAVE TO MONITOR POTENTIAL FOR POOR DRAINAGE/URBAN 
FLOODING FRI MORNING....WHICH WOULD IMPACT THE MORNING COMMUTE.  

REGARDING WINDS FRI...LOW RISK OF STRONG TO DAMAGING WINDS CAPE COD 
AND ISLANDS GIVEN STRENGTH (60KT AT 925 AND 80 KT AT 850MB) OF LOW 
LEVEL JET. HOWEVER LOCAL STUDY FOR SOUTHEAST WIND CASES INDICATES 
STRENGTH OF LOW LEVEL JET NEEDS TO BE ABOUT 10-15 KT STRONGER. IN 
ADDITION...COLD NEAR SHORE WATERS WITH SST IN THE 30S COMBINED WITH 
STRONG WAA ON THE NOSE OF LOW LEVEL JET WILL CREATE A STEEP 
INVERSION. THUS...MIXING/GUSTINESS WILL BE LIMITED. HOWEVER...MODEL 
SOUNDINGS FROM BOTH THE NAM AND GFS INDICATE A LOW RISK OF 
GRADIENT/SUSTAINED WIND REACHING WARNING CRITERIA /35 KT/ ACROSS 
CAPE COD AND THE ISLANDS. MORE LIKELY SCENARIO WOULD BE HIGH END 
WIND ADVISORY WITH WINDS OF 30-40 MPH...MAINLY SUSTAINED WINDS.

FRIDAY NIGHT...
COLUMN DRIES OUT IN RESPONSE TO SHORT WAVE RIDGING OVER THE AREA 
BEHIND DEPARTING INITIAL WAVE. THUS...DRY WEATHER EXPECTED.

SATURDAY...
SHOWERS POSSIBLE...MAINLY IN THE AFTERNOON ACROSS WESTERN PORTIONS 
OF CT/MA AND NH AS TRAILING SHORT WAVE TROF ALONG WITH WEAK SURFACE 
REFLECTION MOVES ACROSS THE AREA.

SUNDAY THROUGH WEDNESDAY...
DRY AND COOL CYCLONIC FLOW SUNDAY AND MONDAY...WITH NEAR SEASONABLE 
TEMPS. BIG DILEMMA IS FOR TUE...AS MODELS RELOAD JET ENERGY INTO 
NORTHEAST/SOUTHEAST CANADA TROF WITH COLD FRONTAL PASSAGE LATE 
MON/MON NIGHT. 00Z ECMWF WAS MOST BULLISH WITH COLD SURGE...LIMITING 
HIGHS TUE IN THE 20S! HOWEVER...12Z RUN HAS BACKED OFF AND IS 
SLIGHTLY WARMER. 12Z GFS REMAINS FLATTEST HERE...WITH 12Z GGEM IN 
BETWEEN. THEREFORE...WE WILL FOLLOW A MODEL BLEND WHICH WILL BE 
SLIGHTLY COOLER THAN MEX GUID BUT WARMER THAN HPC GUID.
 
BY WED...TEMPS MODERATE AS UPPER FLOW BECOMES MORE ZONAL.

&&

.AVIATION...
VFR CONDITIONS EXPECTED OVERNIGHT TONIGHT THROUGH 18Z ON THURSDAY. 
ANY BROKEN STRATOCU WILL DISSIPATE BY EARLY THIS EVENING.
&&

.MARINE...
RELATIVELY TRANQUIL WINDS AND SEAS ARE EXPECTED ON THE LOCAL WATERS 
TONIGHT THROUGH MOST OF THURS NITE. LOW PRESSURE WILL APPROACH FROM 
THE WEST THURSDAY NIGHT WHICH COULD ALLOW FOR SMALL CRAFT OR GALE 
FORCE WINDS BY DAYBREAK FRIDAY. HOWEVER...THIS IS VERY LATE 3RD 
PERIOD OF THE FORECAST SO HAVE HELD OFF ON ANY FLAGS ATTM. 

FRIDAY...
SOUTHEAST WINDS MAY APPROACH GALE FORCE...THEN DIMINISH AND BECOME 
SOUTHWEST FRI EVENING AND NIGHT.

SAT...MODEST SOUTHWEST WINDS.

SUN AND MON...MODEST WEST WINDS WITH A LOW RISK OF WEST-NORTHWEST 
GALES LATE MON NIGHT...AS STRONG COLD FRONT MOVES ACROSS NEW 
ENGLAND. 

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...WINTER STORM WATCH FROM THURSDAY EVENING THROUGH FRIDAY 
     MORNING FOR MAZ002>004-008-010-026.

NH...WINTER STORM WATCH FROM THURSDAY EVENING THROUGH FRIDAY 
     MORNING FOR NHZ011-012-015.

RI...NONE.
MARINE...NONE.
&&

$$

SHORT TERM...EKSTER
LONG TERM...NOCERA
AVIATION...EKSTER
MARINE...NOCERA/EKSTER