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000
FXUS61 KBOX 110703
AFDBOX

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

.SYNOPSIS...

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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 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.
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&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...

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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.
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&&

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

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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.
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&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
*** TRENDING WARMER AND WETTER FOR WED/WED NIGHT STORM ***
*** TYPICAL LARGE TEMPERATURE SWINGS FOR MARCH THIS PERIOD ***

MODEL GUIDANCE AND SYNOPTIC OVERVIEW...

ALL MODEL GUIDANCE INCLUDING THE 12Z GFS/NAM/UKMET/GEFS/ECMWF AND
ECENS HAVE ALL TRENDED NORTH WITH THE SURFACE LOW NOW AND SHOWING
GOOD CLUSTERING AROUND A TRACK ALONG THE COASTAL PLAIN /I95
CORRIDOR/ OF SOUTHERN NEW ENGLAND WED-THU. THIS IS A WARMER SOLUTION
THAN SEEN IN PREVIOUS MODEL RUNS. WHILE THIS IS THE MORE LIKELY
TRACK/SCENARIO AT THIS TIME...NOT EXPECTING MAJOR CHANGES IN FUTURE
MODEL RUNS BUT KEEP IN MIND MODEL PROJECTIONS AT 60+ HRS RARELY
VERIFY EXACTLY.  THUS NEED TO KEEP THE DOOR OPEN FOR SLIGHT COLDER
OR WARMER SOLUTIONS IN LATER MODEL RUNS. THIS DIRECTLY IMPACTS THE
EVOLUTION OF THE RAIN-SNOW AND ACCOMPANYING SNOWFALL FORECAST. THUS
STILL TOO EARLY TO LOCK INTO PRECISE SNOW TOTALS OR TRANSITION
TIMES.

THE TWO PACKETS OF JET ENERGY THAT WILL MERGE AND RESULT IN
EXPLOSIVE CYCLOGENESIS OVER THE NORTHEAST ARE CURRENTLY COMING INTO
THE PACIFIC NORTHWEST AND THE OTHER PACKET OVER NORTHWEST CANADA AND
ALASKA...NOT A DATA RICH AREA. THE AMPLITUDE OF THE TRAILING JET
ENERGY OVER NORTHWEST CANADA AND ALASKA WILL BE KEY...AS MODELS
AGREE THIS FEATURE WILL PROVIDE ENOUGH AMPLITUDE TO BACK THE MID
LEVEL FLOW SUFFICIENTLY FOR A STORM TRACK FARTHER NORTHWEST. AS
MENTIONED ABOVE...STILL 60+ HRS OUT SO FOR NOW WILL BLEND ALL 12Z
MODEL GUIDANCE. HOWEVER WE WILL STAY AWAY FROM THE 12Z NAM THERMAL
FIELDS WHICH ARE DISPLAYING THEIR TYPICAL COLD BIAS AT THIS LONGER
TIME RANGE.

SENSIBLE WEATHER DETAILS...

WED/WED NIGHT...

GOOD MODEL AGREEMENT THAT PRECIP OVERSPREADS THE REGION FROM WEST TO
EAST...POSSIBLY HOLDING OFF UNTIL EARLY AFTERNOON OVER SOUTHEAST MA.
12Z MODEL GUIDANCE SUGGEST PRECIP MAY BEGIN AS SNOW SOMEWHERE ALONG
AND NORTH OF THE MASS PIKE AND INTO SOUTHERN NH...THEN THE RAIN-SNOW
LINE LIFTING NORTHWARD INTO SOUTHERN OR CENTRAL NH BEFORE CRASHING
SOUTHWARD WED NIGHT AS MID LEVEL LOW MOVES EAST ACROSS THE REGION
AND WRAPPING COLDER AIR SOUTHWARD. RAIN-SNOW LIKELY TO CRASH
SOUTHEAST ALL THE WAY TO THE COAST. THEN ISSUE BECOMES HOW MUCH QPF
IS LEFT ONCE COLD AIR ARRIVES. GFS AND ECMWF HANDLE THE EVOLVING
COMMA HEAD DIFFERENTLY...SO LOW CONFIDENCE ON HOW MUCH SNOW WILL
FALL ON THE BACKSIDE. BASED ON THE CURRENT STORM TRACK MOST
CONFIDENCE OF 6"+ ACROSS NORTHWEST INTO SOUTHWEST NH. THAT IS A
COMBINATION OF SNOW ON THE FRONT END WED...MIXED PRECIP WED EVENING
THEN BACK TO SNOW OVERNIGHT WED NIGHT INTO EARLY THU. THUS WINTER
STORM WATCH REMAINS IN EFFECT FOR THIS AREA. WAS TEMPTED TO BRING
THE WATCH FARTHER SOUTH INTO NORTHERN WORCESTER COUNTY AND NORTHWEST
MIDDLESEX...BUT GIVEN PTYPE ISSUES/UNCERTAINTY IN EVOLUTION IN COMMA
HEAD SNOWS AND EVENT STILL 48-60HRS OUT PLENTY OF TIME TO IRON OUT
THESE DETAILS.

LESS SNOW SOUTHWARD BUT A RISK OF A WINTRY MIX FOR A TIME WED FROM
NORTHERN CT-RI TO THE MASS PIKE FOLLOWED BY A PERIOD OF WRAP AROUND
SNOW WED NIGHT INTO THU AM. ELSEWHERE ACROSS MUCH OF CENTRAL-
SOUTHERN RI AND SOUTHEAST MA LITTLE IF ANY SNOWFALL EXPECTED ON THE
FRONT END WED WITH PERIODS OF HEAVY RAIN MORE OF A CONCERN. RISK OF
URBAN POOR DRAINAGE FLOODING AS PWATS CLIMB TO +2 STD ABOVE CLIMO
ALONG WITH THE CHANCE OF TSTMS AS NOSE OF DRY SLOT APPROACHES
/THETA-E DECREASING WITH HEIGHT/ LATE WED-WED NIGHT. WILL LEAVE
TSTMS OUT OF THE FORECAST GIVEN THE TIME RANGE.

WED NIGHT COULD BE SOME CONCERN REGARDING A FLASH FREEZE GIVEN
STANDING WATER FOLLOWED BY VERY STRONG COLD AIR ADVECTION.

THU/FRI...SOME COMMA HEAD SNOWS POSSIBLE THU MORNING. THEN FOCUS
BECOMES ANOMALOUS COLD AIR ADVECTION WITH ENSEMBLE 850 AND 925 MB
TEMP ANOMALIES ON THE ORDER OF -2 STD FROM CLIMO! CORE OF THE COLD
AIR IS OVER NEW ENGLAND 06Z-12Z FRI. GUSTY NW WINDS WILL PROVIDE
BITTERLY COLD WIND CHILLS. LOOKING AT A SUPERBLEND OF ALL MODEL
GUIDANCE FOR LOWS THU NGT/FRI AM...WE ARE WITHIN A FEW DEGS OF
RECORD LOWS AT BOSTON/PROVIDENCE/BRADLEY AND WORCESTER!

WEEKEND...LIKELY MILDER SAT /40S TO NEAR 50 POSSIBLE!/ AS ENSEMBLES
HAVE LOW PRES TRACKING ACROSS SOUTHEAST CANADA. ENSEMBLES SUGGEST
ATTENDING FRONTAL PASSAGE SHOULD BE MAINLY DRY CROSSING THE AREA
SOMETIME LATER SAT/SAT NGT/EARLY SUN. TRENDING COOLER BEHIND THE
FRONT FOR SUNDAY.

&&

.AVIATION /07Z TUESDAY THROUGH SATURDAY/...
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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...MVFR TO START THEN LOWERING TO IFR AND POSSIBLY LIFR IN HEAVY
RAIN MOST OF CT/RI AND SOUTHEAST MA INCLUDING BOSTON WITH HEAVY SNOW
NORTHWEST MA AND SOUTHWEST NH.

PRELIMINARY SNOWFALL FORECAST...

BOS...1-2" POSSIBLE WED NIGHT/THU AM
PVD...1-2" POSSIBLE WED NIGHT/THU AM
BDL...1-2" POSSIBLE WED NIGHT/THU AM
ORH...3-6" POSSIBLE WED/THU
MHT...5-8" POSSIBLE WED/THU

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

FRI/SAT...VFR AND DRY WEATHER LIKELY.
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&&

.MARINE...
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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...INTENSIFYING LOW PRES TRACKS ALONG THE SOUTHERN NEW ENGLAND
COAST. LOW VSBY IN FOG AND HEAVY RAIN.

THU...GALE CENTER EXITS SOUTHEAST MA INTO THE GULF OF MAINE WITH NW
GALES LIKELY. LIGHT FREEZING SPRAY LIKELY WITH A LOW RISK OF
MODERATE FREEZING SPRAY.

FRI/SAT...WINDS EASE FRI BUT THEN SHIFT TO THE SW SAT AND BECOME
GUSTY AS LOW PRES TRACKS ACROSS SOUTHEAST CANADA.
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&&

.TIDES/COASTAL FLOODING...
NO FLOODING EXPECTED GIVEN RELATIVELY LOW ASTRO TIDES AND NOT MUCH
WIND AND SURGE ANTICIPATED AS TRACK OF SURFACE LOW DIRECTLY OVER OR
VERY CLOSE TO THE REGION.

&&

.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...
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CT...NONE.
MA...WINTER STORM WATCH FROM WEDNESDAY MORNING THROUGH THURSDAY
     MORNING FOR MAZ002-003-008-009.
NH...WINTER STORM WATCH FROM WEDNESDAY MORNING THROUGH THURSDAY
     MORNING FOR NHZ011-012-015.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR
     ANZ254>256.
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&&

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