-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KBOX 110756
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
356 AM EDT TUE MAR 11 2014

.SYNOPSIS...
-- Changed Discussion --
DRY AND MILD WEATHER ACROSS THE REGION TODAY.  STRONG LOW PRESSURE
WILL TRACK ACROSS SOUTHERN NEW ENGLAND WED INTO EARLY THU.  HEAVY
RAIN WILL BE THE PRIMARY PRECIPITATION TYPE...EXCEPT ACROSS FAR
NORTHWEST MA/SOUTHERN NH WHERE A PERIOD OF HEAVY SNOW AND FREEZING
RAIN IS POSSIBLE. MOST LOCATIONS WILL END AS A BIT OF SNOW THU
MORNING...BUT THE MAIN STORY WILL BE A BRIEF SHOT OF ARCTIC AIR
USHERED IN ON STRONG NORTHWEST WINDS. MILDER WEATHER RETURNS FRI
AND SAT...BEFORE ANOTHER SHOT OF COLD AIR FOR EARLY NEXT WEEK.
-- End Changed Discussion --

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A BEAUTIFUL SPRING LIKE DAY UNDER A MIXTURE OF CLOUDS AND SUN.  A
MILD START...850 MB TEMPS OVER 0C ALONG WITH WEST TO NORTHWEST FLOW
OFTEN ALLOWS TEMPS TO EXCEED GUIDANCE VALUES THIS TIME OF YEAR.
WILL GO WITH HIGHS BETWEEN 50 AND 55 ACROSS MOST OF THE REGION.
CAN/T RULE OUT A FEW MID TO UPPER 50S ACROSS A SMALL PORTION OF
INTERIOR RHODE ISLAND/SOUTHEAST MA.  NORTHWEST WINDS MAY GUST TO
AROUND 25 MPH THIS AFTERNOON.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM WEDNESDAY/...
TONIGHT...

DRY WEATHER WILL PREVAIL FOR MOST OF TONIGHT...DESPITE AN ABUNDANCE
OF MID LEVEL CLOUDINESS.  WARM ADVECTION WELL IN ADVANCE OF LOW
PRESSURE MAY ALLOW SOME SCATTERED LIGHT PRECIPITATION TO DEVELOP
TOWARDS DAYBREAK...MAINLY NORTHWEST OF I-95.  MODEL SOUNDINGS SHOW
IT WILL PROBABLY BE WARM ENOUGH FOR LIGHT RAIN ACROSS MOST OF
MASSACHUSETTS...WITH THE THE LIGHT SNOW CONFINED TO SOUTHERN NH.
ANY ACCUMULATIONS ACROSS SOUTHERN NH SHOULD JUST BE A DUSTING TO
LESS THAN AN INCH THROUGH 12Z WEDNESDAY.  LOW TEMPS WILL MAINLY BE
IN THE 30S.

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
-- Changed Discussion --
***  WED/WED NIGHT STORM CONTINUES TO TREND WARM/WET ***
*** TYPICAL LARGE TEMPERATURE SWINGS FOR MARCH THIS PERIOD ***

OVERVIEW AND MODEL PREFERENCES...
WITH 11.00Z MODEL GUIDANCE CONTINUING TO HONE IN ON TRACK OF SFC
LOW PRES FOR MID WEEK...WILL BE LEANING ON A BLEND OF NEW GUIDANCE
WITH THIS UPDATE.

THE MAIN ISSUE IS THAT AS BOTH SHORTWAVE ENERGY FROM THE PACIFIC
NW AND DIVING S FROM HUDSON BAY ARE STARTING TO BE BETTER
SAMPLED...GUIDANCE CONTINUES TO HONE IN ON THE FINAL
DEPTH/SHARPNESS OF THE COMBINED TROF ONCE IT REACHES THE NORTHEAST
CONUS. THE TREND IN THE LAST FEW RUNS HAS BEEN TO LIFT THE FINAL
TROF N SOMEWHAT...CARRYING THE RAPIDLY DEEPENING LOW PRES
ATTENDANT TO THIS FINAL WAVE SOLUTION A BIT FURTHER N EACH RUN.
CURRENT TRENDS SUGGEST LOW PRES WILL MOVE FROM THE NYC
METRO...INTO THE BOS METRO BY EARLY THU MORNING...DEEPENING TO THE
MID 970S AS IT GOES. THIS IS SLIGHTLY FURTHER N THAN THE I-95
CORRIDOR TRACK. THIS ALSO HAS SIGNIFICANT THERMAL PROFILE
CONSEQUENCES...SUGGESTING /AT THE VERY LEAST/ THAT H85 +4C LINE
REACHES TO SRN NH IMPLYING WARMER MID LVLS. STILL SOME UNCERTAINTY
ON THIS AS WE ARE STILL 36 OR SO HOURS OUT...BUT WILL BE ADJUSTING
SOMEWHAT TO THIS WARMER SOLUTION WITH THIS UPDATE.

DETAILS...

WED AND WED NIGHT...
VERY STRONG BUT VERY COMPLEX LOW PRES CENTER WILL BE APPROACHING
WED THEN MOVING RAPIDLY ACROSS SRN NEW ENGLAND WED NIGHT. THE KEY
WITH THIS STORM WILL BE THE THERMAL PROFILES AS IT MOVES
THROUGH...AS MOISTURE IS NOT AN ISSUE. PWATS OF 1.0-1.5 INCHES
/NEARLY 2 SD ABOVE NORMAL/ AND VERY STRONG LIFT WITH THE DEEPENING
LOW PRES WILL BE ACCOMPANYING THIS STORM SYSTEM.

SFC WARM FRONT WILL BE APPROACHING FROM THE W EARLY IN THE DAY ON
WED...SLIDING THROUGH THE NRN REACHES THROUGH THE DAY WITH WEAK
ISENTROPIC LIFT. THEREFORE...DO EXPECT SOME LIGHT PRECIP TO BE
SPREADING E THROUGH THE DAY...ESPECIALLY N OF THE MASS
PIKE...INCREASING IN INTENSITY EVERYWHERE THROUGH THE AFTERNOON AS
THE MOISTURE FLUX INCREASES AND THE LOW PRES ITSELF APPROACHES.
THE COMBINATION OF DIURNAL HEATING AND INCREASING WARM ADVECTION
SUGGESTS THIS INITIAL PRECIP IS MOSTLY IN THE FORM OF RAIN...SAVE
FOR SOME AREAS N OF ROUTE 2 WHICH MAY BE COOL ENOUGH INITIALLY TO
START AS SOME LIGHT SNOW BEFORE A CHANGE-OVER.

THERMAL PROFILES AND P-TYPE...
THROUGH THE EVENING AND OVERNIGHT HOURS AS BOTH LIFT INCREASES
AND MID LVL TEMPS CONTINUE TO WARM...EXPECT A BROAD AREA OF RAIN
/SOMETIMES HEAVY GIVEN MODEL SOUNDINGS SHOW MODEST MID LVL
INSTABILITY/. THE LATEST SHIFT N HAS THE H85 +6 LINE APPROACHING
ROUTE 2...WITH THE H92 +10 LINE AT THE MASS PIKE.
THEREFORE...AREAS S OF ROUTE 2 ARE MAY BE RAIN FOR A LONG PERIOD
OF TIME. HOWEVER...EXTREME NRN MA AND SRN NH...NOTE ENOUGH OF A N
COMPONENT TO THE WIND THROUGH THE EVENING TO ALLOW SFC TEMPS TO
GRADUALLY LOWER...POSSIBLY DIPPING BELOW FREEZING AROUND
03-06Z...THEN SHIFTING S WITH TIME. MAY ACTUALLY SEE A CHANGE TO
A PERIOD OF FZRA FROM N TO S /POSSIBLY REACHING THE MA PIKE BY
AROUND 06Z/. FOLLOWING THIS SFC COOLING TREND...AS THE LOW SHIFTS
OFFSHORE AFTER 06Z...THE COMBINATION OF CRASHING HEIGHTS AND
STRONG COLD ADVECTION WILL LEAD TO A RAPID CHANGE OVER TO SNOW
/POSSIBLY STILL HEAVY/ FROM NW TO SE THROUGH 12Z AS H85/H92 TEMPS
DROP RAPIDLY BELOW FREEZING FROM NW-SE. THE BEST CHANCE FOR
PROLONGED HEAVY SNOW LOOKS TO BE MAINLY THE EXTREME NRN REACHES OF
THE BOX CWA. HOWEVER... NOT OUT OF THE QUESTION ALMOST ALL OF
MA/CT/RI SEE AT LEAST SOME SNOW BEFORE ENDING...ALTHOUGH THERE IS
A STRONG SIGNAL DRY SLOT MAY CUT THINGS OFF FOR SRN CT/RI/ AND SE
MA DURING THE EARLY MORNING HOURS THU. WHAT THIS MEANS IS THERE IS
LIKELY TO BE A VERY TIGHT GRADIENT BETWEEN THE HAVE AND HAVE NOTS
FOR SNOWFALL ESPECIALLY FROM ROUTE 2 N. AREAS S OF ROUTE 2 MAY
STRUGGLE TO ACCUMULATE MUCH /IF AT ALL GIVEN THE AFOREMENTIONED
DRY SLOT/. IN A REGION FROM THE MASS PIKE INTO SRN NH...THE
DECLINING SFC TEMPS MAY LEAD TO A PERIOD OF LIGHT ICE
ACCUMULATIONS UNDER FZRA.

GIVEN THE UNCERTAINTY IN THE FZRA/SNOW TRENDS NOT CONFIDENT
ENOUGH IN CHANGING CURRENT WATCH LOCATION WITH THIS UPDATE...AS
THE WARMER TREND MAY LIMIT THE ABILITY FOR BOTH SNOW AND FZRA TO
ACCUMULATE....SUGGEST WARNING CRITERIA MAY ONLY BE ROUTE 2 N /FOR
SNOW POSSIBLY EVEN IN NRN CHESHIRE HILLSBOROUGH/.

RAINFALL...
DESPITE THE UNCERTAINTY IN FINAL P-TYPE ISSUES ESPECIALLY FROM
ROUTE 2 N AND FZRA FROM THE MASS PIKE TO ROUTE 2...AREAS S OF THE
MASS PIKE ARE LIKELY TO REMAIN MOSTLY RAIN UNTIL A BRIEF CHANGE
OVER THU MORNING. WITH VERY HIGH PWATS...STRONG LIFT AND EVEN SOME
MID LVL INSTABILITY APPARENT...HEAVY RAIN AT TIMES MAY LEAD TO
OCCASIONAL URBAN AND POOR DRAINAGE FLOODING AT TIMES.

FLASH FREEZE...
THIS MAY ACTUALLY CARRY OVER INTO THU. STRONG COLD ADVECTION
/ACCOMPANYING THE POTENTIAL CHANGE TO SNOW BEFORE ENDING EARLY THU
MORNING/ MAY LEAD TO SFC TEMPS RAPIDLY DROPPING BELOW FREEZING IN
AREAS THAT HAVE SEEN A FAIR AMOUNT OF RAIN OR A MIX OF
SNOW/RAIN/FZRA. THIS MAY LEAD TO A RAPID FREEZE ALONG AREA
ROADWAYS INTO THE DAY THU...EXACERBATING ALREADY SLIPPERY
CONDITIONS WHERE SNOW/FZRA FELL AND CREATING SLIPPERY CONDITIONS
WHERE ONLY RAIN FELL. FOR SOME /ESPECIALLY CT/RI/SRN MA/ THIS MAY
ACTUALLY BE THE BIGGER ISSUE WHERE ANY STANDING WATER/WET ROADWAYS
ARE OBSERVED.

THU...
LOW PRES MOVING INTO THE BAY OF FUNDY DURING THE DAY WILL LEAD TO
RAPIDLY COOLING TEMPERATURES AND STRONG NW FLOW. MAY STILL SEE
SOME COMMA-HEAD SNOWS THROUGH THE MORNING HOURS ESPECIALLY..BUT
THIS WILL BE DEPENDENT ON THE STRENGTH/DEPTH OF THE DRY SLOT. AN
ADDITIONAL INCH OR SO OF SNOW ACCUMULATION IS NOT OUT OF THE
QUESTION...AND IT MAY BE HERE THAT AREAS AROUND AND S OF THE MASS
PIKE SEE MOST OF THEIR SNOWFALL FROM THIS SYSTEM DURING THE
MORNING HOURS. WILL STILL NEED TO MONITOR FOR ICY CONDITIONS AND
SFC TEMPS RAPIDLY COOL THROUGH THE DAY. H85 TEMPS WILL BE NEAR
-20C BY THU EVENING.

THE OTHER ISSUE WILL BE THE POTENTIAL NEED FOR AT LEAST A WIND
ADVISORY AS NW FLOW DEVELOPS AND SKIES CLEAR DURING THE
AFTERNOON...MIXING TO H85 WHERE A NEAR 50 KT LLJ EXISTS MAY LEAD
TO 35-50 MPH WIND GUSTS AT TIMES ACROSS MUCH OF THE REGION.

THU NIGHT INTO FRI NIGHT...
A COLD START INITIALLY THU NIGHT THANKS TO STRONG NW FLOW AND
COLD AMBIENT TEMPERATURES /WHICH MAY REQUIRE A WIND CHILL ADVISORY
FOR THE INTERIOR AS CHILLS FALL INTO THE NEGATIVE NUMBERS.
HOWEVER...BY FRI AS HIGH PRES NOSES OVER FROM THE SW...A SECOND
ROUND OF RETURN WARMING FLOW IS EXPECTED TO DEVELOP WITH H85 TEMPS
REACHING -2C. COMBINE THIS WITH PARTLY CLOUDY SKIES AND A HIGHER
MARCH SUN ANGLE AND HIGHS COULD APPROACH THE 40S. COOLING INTO THE
30S FRI NIGHT. DRY WX PREVAILS UNDER THE HIGH PRES INFLUENCE.

SAT AND SAT NIGHT...
A COLD FRONT SLIDES THROUGH THE REGION ATTACHED TO WEAK CLIPPER
LOW THROUGH NRN NEW ENGLAND. SFC-MID LVL TEMPS HAVE A CHANCE TO
REBOUND ABOVE FREEZING SO EXPECT ANY PRECIP TO REMAIN AS RAIN.
HOWEVER...THIS FRONT MAY GO THROUGH MOSTLY DRY DUE TO BOTH A LACK
OF LIFT AND MOISTURE. MAINLY SLIGHT TO LOW CHANCE POPS WITH THIS
UPDATE.

EARLY NEXT WEEK...
TRICKY SETUP REGARDING LONGWAVE TROF SETTLING OVER NRN QUEBEC
INTO NEW ENGLAND. EXACT PLACEMENT WILL LEAD TO FINAL STORM-TRACK
SOLUTION AS SHORTWAVE ENERGY APPROACHES.
-- End Changed Discussion --


&&

.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
-- Changed Discussion --
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /TODAY AND TONIGHT/...HIGH CONFIDENCE.

TODAY...ANY PATCHY MVFR CIGS/VSBYS WILL DISSIPATE EARLY THIS
MORNING.  OTHERWISE...VFR CONDITIONS TODAY.  WEST TO NORTHWEST WINDS
MAY GUST INTO THE LOWER 20 KNOTS THIS AFTERNOON.

TONIGHT...VFR CONDITIONS FOR MOST OF THE NIGHT.  MVFR CIGS/VSBYS MAY
OVERSPREAD AREAS NORTHWEST OF I-95 BETWEEN 8Z AND 12Z IN LIGHT
PRECIPITATION.  PTYPE MAINLY LIGHT SNOW IN SOUTHERN NH WITH LIGHT
RAIN ELSEWHERE.

KBOS TERMINAL...HIGH CONFIDENCE IN TAF.

KBDL TERMINAL...HIGH CONFIDENCE IN TAF.

OUTLOOK...WEDNESDAY THROUGH SATURDAY...MODERATE CONFIDENCE.

WED AND WED NIGHT...
MVFR TO START THEN LOWERING TO IFR AND POSSIBLY LIFR IN HEAVY
RAIN MOST OF CT/RI AND SOUTHEAST MA INCLUDING BOSTON WITH A MIX
OF HEAVY SNOW AND FREEZING RAIN NORTHWEST MA AND SOUTHWEST NH.

PRELIMINARY SNOWFALL FORECAST...

BOS...1-2" POSSIBLE WED NIGHT/THU AM
PVD...T-1" POSSIBLE WED NIGHT/THU AM
BDL...T-1" POSSIBLE WED NIGHT/THU AM
ORH...2-4" POSSIBLE WED/THU
MHT...3-6" POSSIBLE WED/THU

THU...
IFR EARLY IMPROVING TO MVFR-VFR. GUSTY NW WINDS UP TO 35-40 KT
POSSIBLE.

FRI/SAT...
VFR AND DRY FRI. SOME LIGHT PRECIP POSSIBLE ON SAT.
-- End Changed Discussion --

&&

.MARINE...
-- Changed Discussion --
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

TODAY...WILL CONTINUE SCA HEADLINES ACROSS OUR SOUTHERN ATLANTIC
WATERS FOR 3 TO 5 FOOT SEAS.  THIS A RESULT OF WEST TO SOUTHWEST
WIND GUSTS OF AROUND 20 KNOTS.  EXPECT CONDITIONS TO REMAIN BELOW
SCA THRESHOLDS ACROSS THE REST OF OUR WATERS...BUT NEAR SHORE WINDS
MAY GUST TO BETWEEN 20 AND 25 KNOTS FOR A FEW HOURS THIS AFTERNOON.

TONIGHT...WEAK PRESSURE GRADIENT WILL KEEP WINDS/SEAS BELOW SCA
THRESHOLDS.  THEREFORE...NO HEADLINES WILL BE NEEDED.

OUTLOOK...WEDNESDAY THROUGH SATURDAY...

WED...MODERATE CONFIDENCE.
MAINLY QUIET BOATING WEATHER TO START...ALTHOUGH WINDS AND SEAS
BEGIN TO PICK UP BY LATE EVENING. SOME LIGHT RAIN POSSIBLE DURING
THE DAY.

WED NIGHT INTO THU...MODERATE CONFIDENCE.
A PERIOD OF GALE FORCE WINDS EXPECTED AS STRONG LOW PRES CROSSES
THE WATERS. FIRST OUT OF THE S...THEN SHIFTING TO NW DURING THE
EARLY MORNING HOURS AND CONTINUING INTO THE DAY THU. THIS WILL BE
ACCOMPANIED BY SOME LIGHT FREEZING SPRAY WITH POCKETS OF MODERATE
FREEZING SPRAY POSSIBLE.

FRI AND SAT...MODERATE CONFIDENCE.
WINDS AND SEAS SLOWLY DIMINISH THU NIGHT INTO FRI...BUT SMALL
CRAFT ADVISORIES WILL LIKELY BE NEEDED UNTIL AT LEAST FRI MORNING.
AFTER A BRIEF LULL AND WINDS SHIFT TO THE S...ANOTHER ROUND OF
WIND GUSTS 25+ KT AND BUILDING SEAS SUGGEST MORE SMALL CRAFTS
NEEDED FOR FRI NIGHT INTO SAT.
-- End Changed Discussion --

&&

.TIDES/COASTAL FLOODING...
-- Changed Discussion --
NO FLOODING EXPECTED GIVEN RELATIVELY LOW ASTRO TIDES AND NOT MUCH
WIND AND SURGE ANTICIPATED AS TRACK OF SURFACE LOW PRESSURE LOOKS
TO BE DIRECTLY OVER SRN NEW ENGLAND. THIS WILL LIMIT THE ABILITY
FOR FETCH IN ANY ONE DIRECTION.
-- End Changed Discussion --

&&

.CLIMATE...
NEAR RECORD COLD POSSIBLE THU NIGHT INTO EARLY FRIDAY. HERE ARE
RECORD LOW TEMPERATURES FOR FRIDAY MARCH 14TH...

BOSTON.......12/1896...FORECAST LOW...15
PROVIDENCE...12/1948...FORECAST LOW...14
BRADLEY ARPT..7/1948...FORECAST LOW...10
WORCESTER.....4/1948...FORECAST LOW...8

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
CT...NONE.
MA...WINTER STORM WATCH FROM WEDNESDAY MORNING THROUGH THURSDAY
     MORNING FOR MAZ002-003.
NH...WINTER STORM WATCH FROM WEDNESDAY MORNING THROUGH THURSDAY
     MORNING FOR NHZ011-012-015.
RI...NONE.
MARINE...GALE WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY EVENING
     FOR ANZ231>235-237-250-251-254>256.
     SMALL CRAFT ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR
     ANZ254>256.
-- End Changed Discussion --

&&

$$
SYNOPSIS...FRANK/DOODY
NEAR TERM...FRANK
SHORT TERM...FRANK
LONG TERM...DOODY
AVIATION...FRANK/DOODY
MARINE...FRANK/DOODY
TIDES/COASTAL FLOODING...STAFF
CLIMATE...STAFF