Area Forecast Discussion
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703
FXUS61 KBOX 121806
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
106 PM EST FRI FEB 12 2016

.SYNOPSIS...
DRY BUT VERY COLD WEATHER IS ON TAP FOR TODAY.  AN OCEAN STORM WILL
TRACK WELL OFFSHORE TONIGHT BUT WILL BRING A PERIOD OF ACCUMULATING
SNOW TO THE CAPE AND ISLANDS. AN ARCTIC FRONT WILL DELIVER
DANGEROUSLY COLD WIND CHILLS OF 20 TO 35 BELOW ZERO LATE SATURDAY
INTO SUNDAY MORNING!  FOR TUESDAY AND TUESDAY NIGHT...A STORM WILL
LIKELY BRING SNOW QUICKLY CHANGING TO RAIN ALONG THE COAST AND TO
FREEZING RAIN AND THEN RAIN INLAND AS MUCH MILDER AIR MOVES INTO NEW
ENGLAND.

&&

.NEAR TERM /THROUGH TONIGHT/...
930 AM UPDATE...
UPDATED T/TD GRIDS FOR CURRENT OBS/TRENDS...OTHERWISE FORECAST ON
TRACK.

STRONG COLD ADVECTION WILL COME TO AN END LATER THIS
MORNING/AFTERNOON AS FLOW TURNS SOUTHWESTERLY AHEAD OF ANOTHER AND
EVEN MORE INTENSE ARCTIC COLD FRONT. NOT TOO MUCH MODERATION
OCCURS THIS AFTERNOON AS 850 MB TEMPS REMAIN BELOW -15C.
THEREFORE...EXPECT HIGH TEMPS TO ONLY RECOVER INTO THE 20 TO 25
DEGREE RANGE THIS AFTERNOON WITH UPPER TEENS HIGHER TERRAIN BUT
WINDS WILL BECOME RELATIVELY LIGHT. SUNNY SKIES THIS MORNING
SHOULD GIVE WAY TO AN INCREASE IN MID LEVEL CLOUDINESS FROM WEST
TO EAST DURING THE LATE AFTERNOON. OCEAN EFFECT CLOUDS WILL ALSO
DEVELOP ALONG THE SOUTH COAST WITH COLD SOUTHWEST FLOW ACROSS OUR
SOUTHERN WATERS.

&&

.SHORT TERM /SATURDAY/...
*** ACCUMULATING SNOW TONIGHT ACROSS CAPE COD AND THE ISLANDS ***

*** BITTERLY COLD AIR INVADES THE REGION SATURDAY AFTERNOON WITH
  STRONG WIND GUSTS AND RAPIDLY FALLING TEMPERATURES ***


TONIGHT...

AN INTERESTING SETUP FOR TONIGHT AS AN OCEAN STORM WILL INTENSIFY AS
IT PASSES WELL SOUTHEAST OF THE BENCHMARK.  AT THE SAME
TIME...POTENT SHORTWAVE ENERGY WILL BE APPROACHING FROM THE WEST
WITH AN ARCTIC COLD FRONT.  THIS WILL SETUP AN INVERTED TROUGH
EXTENDING BACK INTO FAR SOUTHEAST NEW ENGLAND.  THE RESULT WILL BE A
PERIOD OF LOW LEVEL CONVERGENCE FOCUSED ACROSS THE CAPE/ISLANDS.
MODEL SOUNDINGS SHOW MODEST OMEGA ON THE ORDER OF 10 TO 20 MICROBARS
PER SECOND.  WILL ALSO LIKELY HAVE SOME OCEAN ENHANCEMENT WITH LOW
LEVEL SOUTHWEST FLOW RESULTING IN OCEAN INDUCED CAPES BETWEEN 400
AND 500 J/KG.  OVERALL THINK 1 TO 3 INCHES OF SNOW IS A GOOD BET FOR
MOST OF THE CAPE/VINEYARD WITH A LOW RISK OF 4 INCHES.  WILL ISSUE A
SPECIAL WEATHER STATEMENT FOR THESE LOCATIONS...BUT LATER SHIFTS MAY
HAVE TO CONSIDER A WINTER WEATHER ADVISORY. LIFT/FORCING PERSISTS A
BIT LONGER ACROSS NANTUCKET AND WITH A PERIOD OF MODEST
SNOWGROWTH...FEEL 2 TO 4 INCHES IS REASONABLE AND WILL HOIST A
WINTER WEATHER ADVISORY FOR THEM.  BULK OF THE SNOW LOOKS TO FALL
BETWEEN 9 PM AND 5 AM...BUT SOME SNOW SHOWERS MAY PERSIST INTO MID
MORNING SAT.

ACROSS THE REST OF THE REGION...DRY WEATHER WILL DOMINATE TONIGHT.
SOME SNOW SHOWERS MAY BRIEFLY EXTEND BACK INTO RHODE ISLAND/EASTERN
MA WITH MINOR ACCUMS POSSIBLE CLOSER TO THE SOUTH COAST.  A FEW SNOW
SHOWERS/FLURRIES ALSO POSSIBLE ACROSS THE INTERIOR MAINLY TOWARD
DAYBREAK AS THE ARCTIC COLD FRONT APPROACHES.  LOW TEMPS WILL MAINLY
BE IN THE 10 TO 15 DEGREE RANGE WITH UPPER TEENS AND LOWER 20S
ACROSS CAPE/NANTUCKET.

SATURDAY...

ARCTIC COLD FRONT SWEEPS ACROSS THE REGION SATURDAY MORNING.  IT MAY
BE ACCOMPANIED BY A FEW SNOW SHOWERS/FLURRIES...BUT THE MAIN STORY
WILL BE THE DANGEROUSLY COLD AIRMASS THAT WILL INVADE THE REGION.
MIDDAY HIGH TEMPS IN THE MIDDLE TEENS TO LOWER 20S WILL RAPIDLY FALL
BY LATE AFTERNOON/EARLY EVENING.  IN FACT...BY 00Z SUNDAY 850MB
TEMPS WILL BE DOWN TO RARE VALUES OF -26 TO -30C FOR SOUTHERN NEW
ENGLAND STANDARDS. THE RESULT WILL BE EARLY SAT EVENING TEMPS
ALREADY BELOW ZERO ACROSS THE INTERIOR AND SINGLE DIGITS ACROSS THE
COASTAL PLAIN. GIVEN THE EXTREMELY COLD AIR WORKING INTO THE REGION
EXPECT EXCELLENT MIXING.  NORTHWEST WIND GUSTS OF 35 TO 45 MPH WITH
A FEW GUSTS NEAR 50 MPH ARE EXPECTED TO DEVELOP SATURDAY AFTERNOON
AND CONTINUE INTO SAT NIGHT.  WE ALREADY ISSUED A WIND ADVISORY FOR
CAPE COD/NANTUCKET GIVEN VERY STEEP LAPSE RATES AS ARCTIC AIR
STREAMS IN OVER THE RELATIVELY MILD OCEAN.  WIND ADVISORY MAY BE
NEEDED FOR A TIME ACROSS THE REST OF THE REGION...BUT APPEARED TO
MARGINAL TO ISSUE THIS FAR OUT.

&&

.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
*** DANGEROUSLY COLD WIND CHILLS SATURDAY NIGHT ***

HIGHLIGHTS...

* BITTER COLD ARCTIC AIR MOVES INTO SOUTHERN NEW ENGLAND FOR THE
 WEEKEND
* SNOW CHANGING TO RAIN LIKELY TUE AND TUE NIGHT

OVERVIEW AND MODEL PREFERENCES...

MODELS CONTINUE AGREE WELL INTO EARLY NEXT WEEK. THE DEEP
AMPLIFIED FLOW WHICH WILL ALLOW FOR THE COLDEST AIRMASS OF THE
SEASON TO ARRIVE BY LATE SAT...WILL THEN TRANSITION TO MORE ZONAL
FLOW AS THE SOUTHERN STREAM LOOKS TO REGAIN CONTROL.
HOWEVER...WITH SOME LINK TO A VORTEX HOVERING AROUND THE QUEEN
ELIZABETH ISLANDS...THE WARMING TREND WILL NOT LAST...AND GIVE WAY
TO ANOTHER ROUND OF COOLER CONDITIONS TOWARD THE END OF THE WEEK.
GIVEN THERE IS GOOD AGREEMENT...A GENERAL BLEND OF OPERATIONAL
GUIDANCE WILL BE USED AS A BASELINE FOR ALL BUT THE SRN STREAM
DOMINANT SYSTEM MON-TUE. A BLEND OF ENSEMBLES WILL BE USED FOR
THIS FEATURE DUE TO TRACK DISCREPANCIES.

DETAILS...

SAT NIGHT INTO SUN...
REINFORCING ARCTIC SHORTWAVE WILL BE MOVING THROUGH THE LONGWAVE
TROF ACROSS THE REGION. THIS SHORTWAVE WILL HAVE SEVERAL
CONSEQUENCES. IT WILL ALLOW THE DEEPEST OF THE COLD AIR TO SPILL
ACROSS THE REGION...NEARING -30C AT H85. AT THE SAME TIME THE
STRONG MID LVL COLD ADVECTION AND INCREASED ISALLOBARIC RESPONSE
WILL LEAD TO INCREASED WIND ACROSS THE REGION...EXACERBATING AN
ALREADY VERY COLD SITUATION. TEMPS ARE LIKELY TO ALREADY BE NEAR
OR BELOW 0F IN THE INTERIOR BY EVENING AND ONLY DROPPING INTO THE
SINGLE DIGITS TO TEENS BELOW 0F THROUGH THE OVERNIGHT HOURS. THE
INCREASED NW FLOW AT THE SFC...WITH GUSTS 20-30 MPH AT
TIMES...WILL LEAD TO DANGEROUSLY COLD WIND CHILLS BETWEEN -20F AND
-30F OR EVEN -35F IN SPOTS. WILL BE UPGRADING INTERIOR MA/CT AND
RI TO WIND CHILL WARNINGS WITH THIS UPDATE...BUT LEAVE WATCHES
NEAR THE SOUTH COAST WHERE MORE UNCERTAINTY LIE. WILL EXPAND THE
WATCH TO INCLUDE CAPE COD...AS CURRENT NUMBERS SUGGEST IT COULD BE
CLOSE THERE AS WELL. THE HIGHS WILL ONLY REACH INTO THE SINGLE
DIGITS AND TEENS ABOVE 0F ON SUN...SO THE COLD WIND CHILLS ARE
LIKELY TO LINGER WELL INTO THE DAY IN SPITE OF MAINLY SUNNY
CONDITIONS.

THE FINAL ISSUE OF NOTE...IS THAT IT WILL TURN MID LVL WINDS
TOWARD THE N. IN SPITE OF THE FLOW REMAINING MORE NW AT THE SFC.
THIS MAY ALLOW A LONG ENOUGH FETCH ACROSS ANOMALOUSLY WARM GULF OF
MAINE WATERS TO YIELD A HIGHER RISK FOR OCEAN EFFECT SNOWS
ESPECIALLY ACROSS CAPE COD. WITH SST-H85 DELTA-T VALUES NEARING
30C AND NORMALIZED CAPE VALUES AROUND 0.3 WILL NEED TO WATCH IF
ANY BANDS SETUP...ESPECIALLY AS AN INVERTED TROF FROM THE MAINE
COAST SHIFTS N. ACCUMULATING SNOW IS CERTAINLY POSSIBLE GIVEN THE
VERY DESTABILIZED LOW LVLS.

SUN NIGHT INTO MON...
HIGH PRES WILL BE MOVING IN AND CROSSING THE REGION...YIELDING
MAINLY DRY CONDITIONS AND SOME WARMING. H92 TEMPS REBOUND BACK
CLOSER TO -10C...OR AT LEAST CLOSER TO SEASONAL NORMALS. AFTER A
COLD START WITH SEVERAL SITES STILL BELOW 0F /THANKS TO SOME
RADIATIONAL COOLING/ HIGHS REACH INTO THE MID 20S TO LOW 30S.

MON NIGHT INTO TUE NIGHT...
ENSEMBLE MEANS ARE STARTING TO LEAN CLOSER TO AN INSIDE RUNNER
LOW PRES SYSTEM WITH TIES TO GULF OF MEXICO MOISTURE THANKS TO ITS
STRONGER SRN STREAM INFLUENCE. THEREFORE...WILL CONTINUE THE TREND
SET FORTH BY THE PREVIOUS FORECASTER...AND LEAN THE FORECAST IN
THIS DIRECTION. THIS IS BETTER NEWS AS IT DOES NOT PROMOTE GOOD
COLD AIR DAMMING. THEREFORE...THERMAL PROFILES ON BUFKIT SUGGESTS
AN INITIAL SNOWY START LATE MON NIGHT...TRANSITIONING TO AN ALL
RAIN EVENT BY TUE. 40-50 KT LLJ AND PWATS NEARLY 2 STD DEVIATIONS
ABOVE NORMAL SUPPORT THE HIGH QPF MODELS CURRENTLY PROJECT...SO IT
COULD BE THAT LIQUID TOTALS OF AN INCH OR EVEN MORE ARE POSSIBLE
BY THE TIME THIS SYSTEM MOVES OUT TUE NIGHT. CERTAINLY SOMETHING
TO WATCH GIVEN IT WILL BE A MIXED PRECIP EVENT WITH THE POTENTIAL
FOR HEAVY RAIN.

WED INTO FRI...
SECOND ROUND OF ARCTIC AIR MOVES IN ASSOCIATED WITH A COLD
FRONTAL PASSAGE ON WED. THIS AIRMASS IS NOT NEARLY AS DEEPLY COLD
AS THIS WEEKEND/S AIRMASS. H85 TEMPS DROP TO AROUND -22C ON
AVERAGE...SUPPORTED BY ENSEMBLE MEANS. THIS MEANS TEMPS WILL
CERTAINLY REMAIN BELOW NORMAL...BUT NOT AS DANGEROUS AS THIS
WEEKEND/S. WILL STILL NEED TO WATCH FOR WIND CHILL VALUES REACHING
ADVISORY LEVELS FOR SOME MAINLY WED NIGHT INTO THU...WHEN WINDS
ARE AT THEIR STRONGEST. SLIGHT MODERATION EXPECTED BY FRI.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /THROUGH SATURDAY NIGHT/...

TONIGHT...MODERATE CONFIDENCE. EXPECT WIDESPREAD MVFR/IFR IN SNOW
ACROSS CAPE/ISLANDS...MOSTLY FROM 02-09Z. SNOW SHOWERS AND MVFR
WILL LIKELY EXTEND ACROSS PORTIONS OF S COASTAL MA/RI.
OTHERWISE...A MIX OF VFR/MVFR CIGS ACROSS REST OF SNE.

SATURDAY...HIGH CONFIDENCE. VFR/MVFR CIGS EXPECTED WITH A FEW
BRIEF SNOW SHOWERS AS ARCTIC FRONT CROSSES REGION 12-18Z.
INCREASING NW WINDS BEHIND THE FRONT WITH GUSTS TO 35-40 KT
DEVELOPING IN THE AFTERNOON.

SATURDAY NIGHT...MODERATE CONFIDENCE. MOSTLY VFR...BUT A PERIOD OF
MVFR CIGS AND SCT SNOW SHOWERS POSSIBLE ACROSS OUTER CAPE. LOW
PROB THAT SNOW SHOWERS AND LOWER CIGS EXTENDING ACROSS NE MA. NW
GUSTS TO 35-40 KT IN THE EVENING DIMINISHING TO 25 KT OVERNIGHT.

KBOS TERMINAL...HIGH CONFIDENCE IN TAF.

KBDL TERMINAL...HIGH CONFIDENCE IN TAF.

OUTLOOK /SATURDAY NIGHT THROUGH TUESDAY/...

SAT NIGHT THROUGH SUN...HIGH CONFIDENCE.
MAINLY VFR INLAND...WITH SOME MVFR CONDITIONS IN OCEAN EFFECT
CIGS/SNOWS SAT NIGHT INTO EARLY SUN. BITTERLY COLD CONDITIONS WITH
WIND GUSTS 20-30 KT POSSIBLE UNTIL MID DAY SUN.

MON...HIGH CONFIDENCE.
VFR.

MON NIGHT THROUGH TUE...LOW TO MODERATE CONFIDENCE.
BECOMING IFR WITH SNOW CHANGING TO RAIN WITH AREAS OF FOG LATE
MON NIGHT INTO TUE. STRONG SOUTHERLY WINDS ALOFT MAY RESULT IN
SIGNIFICANT LOW LEVEL WIND SHEAR TUE AFTERNOON.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /THROUGH SATURDAY/...HIGH CONFIDENCE.

TODAY...NORTHWEST WIND GUSTS STILL GUSTING OVER 30 KNOTS EARLY THIS
MORNING AS BITTERLY COLD AIR MOVES OVER THE RELATIVELY MILD OCEAN.
WINDS SHOULD CONTINUE TO DIMINISH THIS MORNING AND DROP BELOW SMALL
CRAFT ADVISORY THRESHOLDS BY NOON...AS COLD ADVECTION COMES TO AN
END AND WINDS BECOME SOUTHWEST.  FREEZING SPRAY ADVISORIES CONTINUE
THROUGH 8 AM...BUT SHOULD BE ALLOWED TO EXPIRE ON TIME AS WINDS
DIMINISH.

TONIGHT...WINDS/SEAS REMAIN BELOW SMALL CRAFT THRESHOLDS FOR MOST OF
THE NIGHT...BUT NORTHWEST WINDS WIND GUSTS OF 25 KNOTS WILL DEVELOP
BY DAYBREAK.

SATURDAY...ARCTIC FRONT BLASTS THROUGH WITH EXTREME COLD ADVECTION
OVER THE WATERS.  PRETTY MUCH A SLAM DUNK ON NORTHWEST WIND GUSTS OF
35 TO 40 KNOTS ACROSS ALL WATERS.  HAVE HOISTED GALE HEADLINES
SATURDAY AFTERNOON THROUGH SATURDAY NIGHT.  THE AIRMASS IS SO COLD
THAT MODERATE FREEZING SPRAY WILL HAVE ALREADY DEVELOPED BY EARLY
SAT EVENING.

OUTLOOK /SATURDAY NIGHT THROUGH TUESDAY/...

*** GALE FORCE WINDS AND HEAVY FREEZING SPRAY EXPECTED SAT EVENING
 INTO EARLY SUN ***

SATURDAY NIGHT INTO SUNDAY...HIGH CONFIDENCE.
STRONG AND BITTERLY COLD NORTHWEST WINDS WILL GUST TO GALE FORCE
THROUGHOUT THE NIGHT AND INTO EARLY SUNDAY. THIS WILL BE
ACCOMPANIED BY A RISK FOR HEAVY FREEZING SPRAY. GALE WARNINGS AND
FREEZING SPRAY WATCHES HAVE BEEN ISSUED FOR THIS RISK. CONDITIONS
DROP TO SMALL CRAFT THRESHOLDS BY LATE SUN. OCEAN EFFECT SNOWFALL
IS LIKELY ACROSS SOME OF THE OTHER EASTERN WATERS.

SUN NIGHT INTO MON...HIGH CONFIDENCE.
BRIEF RIDGE OF HIGH PRES MOVES ACROSS THE WATERS. THIS WILL ALLOW
ANY SMALL CRAFT ADVISORIES TO DROP BY EARLY MON MORNING WITH
MAINLY QUIET BOATING WEATHER TO FOLLOW FOR THE REST OF MON.

MON NIGHT INTO TUE...MODERATE CONFIDENCE.
WINDS SHIFT TO THE SW AS LOW PRES APPROACHES FROM THE SW. WINDS
AND SEAS MAY REACH SMALL CRAFT THRESHOLDS AS EARLY AS TUE MORNING
AND THEN CONTINUE THROUGH THE DAY. SOME RAIN/FOG MAY LEAD TO LOWER
VISIBILITIES.

&&

.CLIMATE...
BITTERLY COLD TEMPERATURES ARE EXPECTED THIS WEEKEND. RECORD COLD
HIGH AND LOW TEMPERATURES MAY BE TIED OR BROKEN. HERE ARE THE
CURRENT RECORDS FOR THE WEEKEND.

RECORD COLD HIGHS FOR FEB 13TH - 14TH...

BOSTON.......15/1979 - 14/1916
HARTFORD.....11/1979 - 11/1979
PROVIDENCE...10/1979 - 10/1979
WORCESTER.... 8/1899 -  7/1979
BLUE HILL.... 9/1899 - 10/1979

RECORD COLD LOWS FOR FEB 13TH - 14TH - 15TH...

BOSTON...... -3/1967 -  -3/1934 - -14/1943
HARTFORD.... -7/1967 -  -9/1979 - -18/1943
PROVIDENCE.. -5/1967 -  -7/1979 - -14/1943
WORCESTER...-12/1967 - -11/1979 - -19/1943
BLUE HILL...-10/1967 -  -9/1979 - -18/1943

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WIND CHILL WARNING FROM 4 PM SATURDAY TO NOON EST SUNDAY FOR
     CTZ002>004.
MA...WIND CHILL WARNING FROM 4 PM SATURDAY TO NOON EST SUNDAY FOR
     MAZ002>019-026.
     WIND CHILL WATCH FROM SATURDAY AFTERNOON THROUGH SUNDAY
     AFTERNOON FOR MAZ020>022.
     WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 9 AM EST
     SATURDAY FOR MAZ024.
     WIND ADVISORY FROM 11 AM SATURDAY TO 4 AM EST SUNDAY FOR
     MAZ022-024.
RI...WIND CHILL WARNING FROM 4 PM SATURDAY TO NOON EST SUNDAY FOR
     RIZ001>004.
     WIND CHILL WATCH FROM SATURDAY AFTERNOON THROUGH SUNDAY
     AFTERNOON FOR RIZ005>007.
MARINE...HEAVY FREEZING SPRAY WATCH FROM SATURDAY AFTERNOON THROUGH
     SUNDAY MORNING FOR ANZ231>235-250-251.
     GALE WARNING FROM 11 AM SATURDAY TO 7 AM EST SUNDAY FOR
     ANZ230>237-250-251-254>256.

&&

$$
SYNOPSIS...FRANK/DOODY
NEAR TERM...KJC/FRANK
SHORT TERM...FRANK
LONG TERM...DOODY
AVIATION...KJC/DOODY
MARINE...FRANK/DOODY
CLIMATE...



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