Area Forecast Discussion
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000
FXUS61 KBOX 301005
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
505 AM EST FRI JAN 30 2015

.SYNOPSIS...
LOW PRESSURE WILL WEAKEN OVER SOUTHERN QUEBEC AS A SECONDARY LOW
DEVELOPS ALONG THE SOUTHERN NEW ENGLAND COAST THIS AFTERNOON AND
INTENSIFIES OVER THE GULF OF MAINE TONIGHT BRINGING WITH IT A
PERIOD OF SNOW FOR THE FORECAST AREA. BLUSTERY AND VERY COLD
CONDITIONS ARE EXPECTED THIS WEEKEND. WATCHING FOR THE POTENTIAL
OF NOREASTERS NEXT WEEK...ONE POSSIBLE SUNDAY NIGHT INTO MONDAY
AND ANOTHER POSSIBLE WEDNESDAY NIGHT INTO THURSDAY. LOW CONFIDENCE
ON BOTH.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AREA OF LIGHT SNOW MOVING ACROSS SNE EARLY THIS MORNING. PRECIP
NOT VERY ORGANIZED AND ASSOCD WITH WEAK OVERRUNNING AHEAD OF
PARENT LOW ACROSS THE EASTERN LAKES.

AMPLIFYING MID LEVEL TROF ACROSS THE GT LAKES BECOMES NEG TILTED
AS IT REACHES THE COAST LATE TODAY. ASSOCD HEIGHT FALL CENTER AND
SHORTWAVE ENERGY WILL RESULT IN PARENT LOW FILLING ACROSS
NORTHERN NEW ENG WITH CYCLOGENESIS NEAR OR SOUTH OF CAPE COD
LATER THIS AFTERNOON. EXPECT A PERIOD OF MAINLY LIGHT SNOW
TODAY AHEAD OF THE OPEN MID LEVEL WAVE WHICH SHOULD TAPER OFF
THIS AFTERNOON ACROSS THE CT VALLEY TO THE RI COAST. WARMING
BOUNDARY LAYER ALONG THE IMMEDIATE SE NEW ENG COAST WILL RESULT
IN RAIN OR MIXED RAIN/SNOW FOR THE CAPE AND ISLANDS.

USED A BLEND OF MODEL QPF WHICH RESULTS IN SNOW ACCUM THROUGH
TODAY OF 1-2 INCHES AWAY FROM THE COAST...WITH UP TO 3 INCHES
NORTH CENTRAL AND NW MA. ALONG THE S COAST...EXPECT LESS THAN AN
INCH.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/...
TONIGHT INTO SATURDAY...

NEG TILT TROF EVOLVES INTO A CLOSED MID LEVEL OVER SOUTHERN NEW
ENGLAND THIS EVENING THEN IT JUMPS TO THE GULF OF MAINE LATER
TONIGHT. THE SFC LOW DEEPENS RAPIDLY TONIGHT IN THE GULF OF MAINE
BUT LIKELY REMAINS A BIT TOO FAR OFFSHORE TO ROTATE HEAVY SNOW
BACK ACROSS SNE AS THE HEAVIER PRECIP WILL REMAIN TO THE NORTH
OVER MAINE. HOWEVER...A ROBUST COMMA HEAD WILL DEVELOP TO THE
WEST OF THE MID LEVEL LOW TONIGHT AND EXTEND ACROSS EASTERN NEW
ENG WHICH WILL LIKELY BRING BANDS OF SNOW TO THE REGION.

THE WESTWARD EXTENT OF THE SNOW TONIGHT WILL LIKELY BE ACROSS
CENTRAL MA AND RI WITH THE MAIN FOCUS ACROSS E MA INCLUDING THE
CAPE/ISLANDS. MAINLY DRY WEATHER EXPECTED IN THE CT VALLEY.
MODELS BACKED OFF A BIT ON THE QPF SO WE HAVE LOWERED SNOW ACCUM A
TAD...BUT HAVE TO WATCH NE MA AND CAPE COD WHICH WILL BE CLOSEST
TO THE BEST FORCING.

SNOW LINGERS ACROSS E MA INTO SAT MORNING...BEFORE GRADUALLY
MOVING OUT. THE OUTER CAPE WILL BE LAST TO DRY OUT AROUND MIDDAY.
OTHERWISE...CLEARING SKIES WILL DEVELOP FROM WEST TO EAST LATE
MORNING THROUGH THE AFTERNOON BUT WINDY AND VERY COLD SATURDAY
WITH HIGHS MOSTLY IN THE TEENS.

WE KEPT THE WINTER STORM WARNING FOR ESSEX COUNTY BUT DOWNGRADED
MIDDLESEX COUNTY TO AN ADVISORY. EXPANDED THE ADVISORY TO CAPE
COD WHICH SHOULD GET INTO A DECENT BAND OF SNOW TONIGHT.
OTHERWISE...DROPPED THE ADVISORY FOR NE CT...N RI AND ADJACENT SE
MA WHERE SNOW AMOUNTS SHOULD FALL SHY OF ADVISORY CRITERIA.

TOTAL SNOW ACCUM OF 4-7 EXPECTED ACROSS NE MA WITH THE MAX
AMOUNTS IN ESSEX COUNTY...WITH 2-4 INCHES CENTRAL MA TO E COASTAL
MA INCLUDING CAPE COD. AN INCH OR 2 POSSIBLE NEAR THE S COAST.

IN ADDITION TO THE SNOWFALL TONIGHT...NORTHWEST WINDS WILL
INCREASE LATE TONIGHT INTO SAT WITH GUSTS TO 40 TO 45 MPH AS LOW
INTENSIFIES EAST OF MA. LOW PROB WIND GUSTS COULD REACH 50 MPH
NEAR THE S COAST AND WIND ADVISORIES MAY EVENTUALLY BE NEEDED.

VERY COLD AIR MOVES IN TONIGHT INTO SATURDAY COMBINED WITH GUSTY
NW WINDS WILL RESULT IN DANGEROUSLY COLD WIND CHILLS OF 10 TO 20
BELOW ZERO IN CENTRAL AND WESTERN MA AND PORTIONS OF N CT WHERE
WIND CHILL ADVISORIES HAVE BEEN ISSUED. WIND CHILLS 5 TO 10 BELOW
IN THE COASTAL PLAIN.

&&

.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
HEADLINES...

* SNOW ENDS ACROSS EASTERN AREAS EARLY SATURDAY FOLLOWED BY ARCTIC
  HIGH PRESSURE FOR THE REST OF THE WEEKEND
* WATCHING FOR POTENTIAL NOREASTERS NEXT WEEK

AN ACTIVE WEATHER PATTERN WILL CONTINUE ACROSS SOUTHERN NEW ENGLAND.
OCEAN STORM OFF THE MAINE COAST ON SATURDAY WILL EXIT TO THE EAST...
BRINGING AN END TO ANY SNOWFALL ACROSS COASTAL LOCALES SATURDAY
MORNING. IMPROVING CONDITIONS WILL OCCUR DURING THE DAY ON A
BLUSTERY NW WIND FLOW AS A COLD AIRMASS MOVES INTO NEW ENGLAND FROM
CANADA. THIS WILL ENSURE A VERY COLD WEEKEND WITH TEMPS RUNNING WELL
BELOW AVERAGE.

THE SYNOPTIC PATTERN NEXT WEEK WILL FEATURE SHORTWAVES DIVING INTO
THE UPPER MIDWEST AND ACROSS NEW ENGLAND. THIS WILL ALLOW FOR
POTENTIAL NOREASTERS TO DEVELOP. HOWEVER, MUCH WILL DEPEND ON HOW
SHARP THE TROUGHS BECOME...WHETHER THEY BECOME NEGATIVELY TILTED AND
PHASE OR NOT WITH SOUTHERN STREAM ENERGY.

THERE HAVE BEEN MODEL DIFFERENCES FROM BOTH GFS/ECMWF IN TERMS OF
THE STRENGTH AND TRACK OF THE LOWS SO WILL FOLLOW A BLENDED MODEL
APPROACH. THE TIMING OF THESE POTENTIAL SYSTEMS LOOKS TO BE SUNDAY
NIGHT AND MONDAY AND AGAIN WEDNESDAY NIGHT THROUGH THURSDAY. THESE
ARE THE PERIODS TO MONITOR FOR POTENTIAL HIGH IMPACTS TO THE AREA.
WHETHER OR NOT WE RECEIVE SIGNIFICANT ADDITIONAL SNOWFALL OR THESE
OCEAN STORMS MISS US TO THE EAST IS JUST TOO TOUGH TO SAY WITH ANY
DEGREE OF CONFIDENCE. SO STAY TUNED.

FOR THE SUN NIGHT-MONDAY LOW...BOTH THE OPERATIONAL 29.12Z GFS AND
ECMWF RUNS HAVE THE LOW CENTER PASSING JUST OUTSIDE THE BENCHMARK
WHICH WOULD MEAN A GLANCING BLOW TO SOUTHEASTERN NEW ENGLAND...BUT
STILL A PLOWABLE SNOWFALL TO EASTERN AREAS. HOWEVER, A FEW ENSEMBLE
MEMBERS ARE FURTHER NORTHWEST WITH THE LOW TRACK...SO A MORE
SIGNIFICANT IMPACT IS A POSSIBILITY...AS IS NO IMPACT IF THE LOW
WERE TO TRACK EVEN FURTHER OFF SHORE. THE FIRST RUNS OF THE
OPERATIONAL ECMWF FOR THE BLIZZARD OF 2015 DIDN`T SHOW MAJOR IMPACTS
TO NEW ENGLAND UNTIL 72 HR IN ADVANCE OF THE EVENT. WE ARE STILL
OUTSIDE OF THIS WINDOW...SO LOTS CAN CHANGE.

TUESDAY WILL BE A LULL DAY IF THE AFOREMENTIONED LOW IMPACTS NEW
ENGLAND. THEN WE LOOK TO YET ANOTHER POTENTIAL OCEAN STORM MID
WEEK...WITH MODELS CENTERING ON THE WED NIGHT-THU TIMEFRAME. THE
29.12Z OPERATIONAL ECMWF IS AGGRESSIVE WITH THIS LOW...SLAMMING
HEAVY SNOWS OVER THE INTERIOR WITH A SNOW TO RAIN SCENARIO FOR THE
COAST. HOWEVER, THE GFS DOES NOT PHASE THE NORTHERN AND SOUTHERN
STREAMS...SO IS PROGRESSIVE AND SHOWS MINIMAL IMPACTS. SO USED A
MODEL BLEND AND...ONCE AGAIN...TOO EARLY TO BANK ON EITHER A HIT OR
A MISS. CERTAINLY A LOT TO MONITOR CLOSELY IN THE DAYS AHEAD!

&&

.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM...THROUGH SATURDAY...MODERATE CONFIDENCE.

THROUGH 12Z...LIGHT SNOW OVERSPREADING THE REGION WITH CONDITIONS
LOWERING TO MVFR/IFR. SNOW MIXING WITH OR CHANGING TO RAIN
CAPE/ISLANDS TOWARD DAYBREAK.

TODAY...MVFR/IFR IN AREAS OF SNOW...WITH RAIN CAPE/ISLANDS.
SNOW TAPERS OFF AND ENDS CT VALLEY TO THE RI COAST DURING THE
AFTERNOON WITH MAINLY MVFR CIGS...BUT PERIODS OF SNOW CONTINUE
CENTRAL AND E MA. GUSTY NW WINDS TO 25 KT DEVELOPING CT VALLEY BY
LATE AFTERNOON.

TONIGHT...MAIN FOCUS FOR AREAS OF SNOW AND MVFR/IFR CONDITIONS
WILL BE ACROSS E MA...WITH VFR CT VALLEY. GUSTY NW WINDS DEVELOP
FROM WEST TO EAST IN THE EVENING WITH GUSTS TO 30-40 KT AFTER
MIDNIGHT.

SATURDAY...LINGERING MVFR/IFR IN AREAS OF LIGHT SNOW ACROSS E MA
AND CAPE/ISLANDS EARLY...OTHERWISE IMPROVING TO VFR WITH CLEARING
SKIES FROM WEST TO EAST. GUSTY NW WINDS TO 35-40 KT.

KBOS TAF...MODERATE CONFIDENCE.

KBDL TAF...MODERATE CONFIDENCE.

OUTLOOK /SATURDAY NIGHT THROUGH MONDAY/...

SATURDAY NIGHT-SUNDAY...HIGH CONFIDENCE. VFR. NW WINDS GUSTING TO
25-35 KNOTS SATURDAY...HIGHEST ALONG THE COAST. LIGHTER WINDS
SUNDAY.

SUNDAY NIGHT-MONDAY...LOW CONFIDENCE. LOW PRES DEVELOPS S OF THE
REGION...BUT TRACK REMAINS UNCERTAIN. TOO EARLY TO HAVE ANY
CONFIDENCE ON VFR OR IFR THIS PERIOD.

TUESDAY...MODERATE CONFIDENCE. IF LOW IMPACTS THE TERMINALS MONDAY,
CONDITIONS WOULD BE IMPROVING ON TUE.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /THROUGH FRIDAY/...HIGH CONFIDENCE.

TODAY...SOUTHERLY WINDS WILL SHIFT TO W THEN NW DURING FRI
AFTERNOON...WITH GUSTS TO 25 KT DEVELOPING ACROSS RI COASTAL
WATERS BY LATE AFTERNOON.

TONIGHT AND SATURDAY...AS LOW PRES INTENSIFIES OVER WESTERN GULF
OF MAINE...GALE FORCE NW WINDS WILL DEVELOP. GUSTS TO 40-45 KT
EXPECTED LATE TONIGHT INTO SAT. THE GUSTY WINDS AND ROUGH SEAS
COMBINED WITH ARCTIC AIR MOVING INTO THE REGION WILL RESULT IN
AREAS OF MODERATE FREEZING SPRAY OVER THE NEARSHORE WATERS SO
FREEZING SPRAY ADVISORIES WERE ISSUED. SNOW REDUCES VSBY OVER
EASTERN WATERS TONIGHT INTO SAT MORNING.

OUTLOOK /SATURDAY NIGHT THROUGH MONDAY/...MODERATE CONFIDENCE

SATURDAY NIGHT...WINDS AND SEAS WILL DIMINISH AS LOW PRESSURE
DEPARTS THE AREA.

SUNDAY...EXPECT WINDS TO DIMINISH BUT REMAIN AT SMALL CRAFT
LEVELS...THOUGH SOME GALE GUSTS MAY LINGER ON THE EASTERN OUTER
WATERS EARLY. SEAS WILL SLOWLY SUBSIDE...BUT WILL REMAIN AOA 5 FT
ON THE OUTER WATERS.

SUNDAY NIGHT-TUESDAY...HIGHLY DEPENDENT ON STRENGTH AND TRACK OF
DEVELOPING LOW PRESSURE SOUTH OF THE REGION AND THUS A LOW
CONFIDENCE FORECAST. WORSE CONDITIONS WOULD BE MONDAY WITH SLOW
IMPROVEMENT ON TUESDAY.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...WINTER WEATHER ADVISORY UNTIL 8 AM EST SATURDAY FOR MAZ004-005-
     012>016-018-019-026.
     WIND CHILL ADVISORY FROM 11 PM THIS EVENING TO 11 AM EST
     SATURDAY FOR MAZ002-008-009.
     WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 8 AM EST
     SATURDAY FOR MAZ022.
     WINTER STORM WARNING UNTIL 8 AM EST SATURDAY FOR MAZ006-007.
RI...NONE.
MARINE...FREEZING SPRAY ADVISORY FROM 11 PM THIS EVENING TO 6 PM EST
     SATURDAY FOR ANZ231>235-237-250-251.
     GALE WARNING FROM 11 PM THIS EVENING TO 6 PM EST SATURDAY FOR
     ANZ232-250-254-255.
     GALE WARNING FROM MIDNIGHT TONIGHT TO 6 PM EST SATURDAY FOR
     ANZ230-231-233-234-251.
     GALE WARNING FROM 1 AM TO 1 PM EST SATURDAY FOR ANZ236.
     GALE WARNING FROM 9 PM THIS EVENING TO 6 PM EST SATURDAY FOR
     ANZ235-237.
     GALE WARNING FROM 7 PM THIS EVENING TO 6 PM EST SATURDAY FOR
     ANZ256.

&&

$$
SYNOPSIS...KJC
NEAR TERM...KJC
SHORT TERM...KJC
LONG TERM...99
AVIATION...KJC/99
MARINE...KJC/99



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