Area Forecast Discussion
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000
FXUS61 KBOX 101200
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
700 AM EST WED FEB 10 2016

.SYNOPSIS...
FAST MOVING LOW PRESSURE WILL BRING SCATTERED BUT LOCALLY HEAVY SNOW
SHOWERS TODAY.  MAINLY DRY WEATHER IS EXPECTED BY TONIGHT...BUT A
COLD FRONT WILL BRING THE RISK FOR MORE SCATTERED SNOW SHOWERS ON
THURSDAY. BITTERLY COLD WEATHER IS EXPECTED THIS WEEKEND. THERE
IS POTENTIAL FOR MORE PRECIP EARLY NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...


...SCATTERED BUT LOCALLY HEAVY SNOW SHOWERS MAY RESULT IN SOME
UNTREATED ROADWAYS QUICKLY BECOMING SNOW COVERED TODAY...

7 AM UPDATE...
YET ANOTHER SHORTWAVE IS MOVING INTO SRN NEW ENGLAND WITH
ATTENDANT MESO-LOW PRES UPSTREAM. THIS IS ALREADY BEGINNING TO
LEAD TO LIGHT SN ACROSS CT AND WRN MA THIS MORNING WITH LIGHT
ACCUMS ALREADY BEING REPORTED. IT WILL TAKE SOME TIME TO SPREAD
E...GIVEN FAIRLY DRY DWPTS REPORTED ACROSS THE REGION.
HOWEVER...MOST OF THE REGION WILL AT LEAST SEE A RISK FOR
SHSN...EVEN AS THIS FIRST MECHANISM DIMINISHES...THE LOW-LVL
INSTABILITY WILL BEGIN TO MAKE UP THE DIFFERENCE THANKS TO STRONG
COLD ADVECTION ALOFT AND MODEST MOISTURE AVAILABLE ABOVE THE SFC.
MAINTAINED SOME POPS THROUGH THE DAY FOLLOWING PREVIOUS
FORECASTER/S LEAD.

PREVIOUS DISCUSSION...

POTENT SHORTWAVE TROUGH WILL BE LIFTING NORTHEAST ACROSS THE REGION
TODAY.  IN RESPONSE...SCATTERED SNOW SHOWERS WILL LIKELY OVERSPREAD
WESTERN MA/NORTHERN CT BY 12Z AND WORK INTO THE REST OF THE REGION
LATER THIS MORNING/EARLY AFTERNOON.  THE MODELS CONTINUE TO SHOW
VERY FAVORABLE INGREDIENTS FOR BRIEF LOCALLY HEAVIER SNOW SHOWERS.
LOW LEVEL MOISTURE WILL COMBINED WITH STEEP MID LEVEL LAPSE RATES ON
THE ORDER OF 7C TO 8C/KM AND TOTAL TOTALS BETWEEN 55 AND 60!
THEREFORE...WILL HAVE TO BE ON THE LOOK OUT FOR BRIEF HEAVY SNOW
SHOWERS THAT CAN QUICKLY COVER ROADWAYS AND RESULT IN POOR
VISIBILITY. GIVEN THE POTENTIAL IMPACT TO MOTORISTS WILL CONTINUE
THE SPECIAL WEATHER STATEMENT.  WHILE THESE LOCALIZED HEAVIER SNOW
SHOWERS WILL BE POSSIBLE LATER THIS MORNING...A BETTER CHANCE MIGHT
BE THIS AFTERNOON WHEN DIURNAL HEATING INCREASES INSTABILITY. THE
BULK OF THE SCATTERED SNOW SHOWERS SHOULD EXIT THE REGION BY 00Z
THIS EVENING...BUT STILL MAY IMPACT THE EVENING RUSH HOUR.

SNOW ACCUMULATIONS GENERALLY WILL RANGE FROM A COATING TO 2 INCHES
IN MOST LOCATIONS. ONE ADDITIONAL THING WE ARE WATCHING IS A MESO
LOW THAT WAS SPINNING OFF THE NEW JERSEY COAST.  SOME GUIDANCE
YESTERDAY INDICATED IT MAY AFFECT PORTIONS OF OUR SOUTHERN ZONES.
THE LATEST DATA HAS TRENDED FURTHER SOUTH AND WE SHOULD NOT
EXPERIENCE A DIRECT IMPACT FROM IT.  HOWEVER...ITS POSSIBLE THAT A
MINI INVERTED TROUGH DEVELOPS AND EXTENDS BACK TOWARDS EASTERN NEW
ENGLAND THIS AFTERNOON/EARLY EVENING INCREASING THE AREAL
COVERAGE/INTENSITY OF SNOW SHOWERS.

&&

.SHORT TERM /THURSDAY/...
TONIGHT...

AS MENTIONED IN THE PREVIOUS SECTION...BULK OF THE SCATTERED SNOW
SHOWERS SHOULD HAVE EXITED THE COAST BY 00Z.  OTHERWISE...MUCH OF
THE NIGHT WILL FEATURE DRY WEATHER OTHER THAN PERHAPS A SPOT
FLURRY/SNOW SHOWER.  LOW TEMPS WILL MAINLY BE IN THE UPPER TEENS TO
LOWER 20S.

THURSDAY...

ANOTHER POTENT SHORTWAVE AND ASSOCIATED COLD FRONT WILL MOVE ACROSS
THE REGION ON THURSDAY.  IN RESPONSE...SCATTERED FLURRIES/SNOW
SHOWERS MAY BE ON GOING BY EARLY THU MORNING ACROSS PORTIONS OF
WESTERN MA/NORTHERN CT. THIS ACTIVITY MAY OVERSPREAD THE REST OF THE
REGION LATER IN THE MORNING AND AFTERNOON.  WHILE WE CAN/T RULE OUT
SOME LOCALIZED HEAVIER SNOW SHOWERS...DRY AIR WORKING IN THE
BOUNDARY LAYER MAY LIMIT THAT POTENTIAL COMPARED TO TODAY.  IT WILL
ALSO BE COLDER ON THURSDAY WITH HIGHS MAINLY IN THE UPPER 20S TO
AROUND 30. WESTERLY WIND GUSTS WILL ALSO INCREASE TO BETWEEN 25 AND
35 MPH BY MID TO LATE AFTERNOON BEHIND THE COLD FRONT.

&&

.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
HIGHLIGHTS...

* SNOW SHOWERS POSSIBLE THROUGH SAT
* MUCH COLDER AIR MOVES INTO SOUTHERN NEW ENGLAND FOR THE WEEKEND
* MORE PRECIPITATION POSSIBLE EARLY NEXT WEEK

OVERVIEW AND MODEL PREFERENCES...

WITH A MODESTLY NEGATIVE NAO/AO REGIME...A LONGWAVE TROF REMAINS
IN PLACE ACROSS ERN CANADA AND ACTS AS A CONDUIT FOR COLD AIR TO
ENTER NEW ENGLAND INTO EARLY NEXT WEEK. THIS COLD AIR COMES AS A
SERIES OF ARCTIC SHORTWAVES...THE DEEPEST AND STRONGEST OF WHICH
WILL BRING ABOUT THE COLDEST AIRMASS OF THE SEASON THUS FAR THIS
WEEKEND. IT ALSO SUGGESTS A RELATIVELY ACTIVE PATTERN WITH A
NEARLY DAILY LOW RISK FOR SHSN ACROSS THE REGION UNTIL THE PROGGED
SHIFT OCCURS EARLY NEXT WEEK. THERE IS ENOUGH AGREEMENT BETWEEN
OPERATIONAL MODELS THAT A BLEND OF THESE MODELS WILL WORK AS A
BASELINE FOR THIS FORECAST.

DETAILS...

THU NIGHT INTO FRI...
THE FIRST SHORTWAVE WILL ALREADY BE SLIDING E OF THE REGION BY
THU EVENING...ALLOWING ANY DIURNALLY DRIVEN SHSN TO DISSIPATE.
MODEST RIDGING IN BETWEEN THIS WAVE AND THE STRONGER ARCTIC WAVE
FOR THE WEEKEND...WILL BUILD ACROSS THE AREA YIELDING A MAINLY DRY
24 HR PERIOD. MODEST INCREASE IN H92 TEMPS FROM ABOUT -18C TO
ABOUT -12C BY 00Z FRI WILL STILL KEEP TEMPS COLD...MINS IN THE
SINGLE DIGITS WITH HIGHS ONLY IN THE 20S.

FRI NIGHT INTO SAT...
STRONG ARCTIC FRONT ASSOCIATED WITH LOW PRES DIVING SE OUT OF
ONTARIO WILL BRING IN ONE OF THE COLDEST AIRMASSES WE HAVE SEEN IN
SOME TIME. THERE IS EXPECTED TO BE SOME INTERACTION WITH THE SRN
STREAM...BUT MAINLY OFFSHORE WITH STRONG BOMBING CYCLOGENESIS
OCCURRING TOO FAR DOWNSTREAM. ENSEMBLES/OPERATIONAL MODELS
CONTINUE TO AGREE HERE...SO SUSPECT DIRECT IMPACT FROM THIS
BOMBING LOW TO MINIMAL AT THIS TIME. OTHERWISE...ISALLOBARIC PRES
COUPLET MAINLY W-E ORIENTED SUGGESTS THAT STRONG FLOW WITH STRONG
PRES GRADIENT MAY HAVE TOO MUCH OF A WESTERLY COMPONENT FOR OCEAN
EFFECT. HOWEVER...ANY SHIFT TO THE N...WITH SST-H85 DELTA-T VALUES
EXCEEDING 25C...COULD YIELD SOME ADVISORY LEVEL /IF NOT HIGHER/
SNOWFALL FOR CAPE COD. THE STRONG COLD ADVECTION BEGINNING LATE
FRI NIGHT MEANS THERE WILL BE LITTLE INCREASE FROM THE MINS IN THE
SINGLE DIGITS AND TEENS TO THE HIGHS ON SAT.

SAT NIGHT INTO SUN...
H92/H85 TEMPS DROP TO ALMOST 4 STD DEVIATIONS BELOW NORMAL /NEAR
-30C AT H85/. THIS WILL COMBINE WITH A FAIRLY PERSISTENT N-S PRES
GRADIENT TO YIELD BLUSTERY CONDITIONS. AMBIENT TEMPERATURES ALONE
WILL STRUGGLE TO REACH INTO THE POSITIVE SINGLE DIGITS. WITH WIND
GUSTS 20-30 MPH...THIS WILL LIKELY LEAD TO NEGATIVE DOUBLE DIGIT
WIND CHILLS SAT NIGHT INTO EARLY SUN. WIND CHILL
ADVISORIES/WARNINGS ARE LOOKING QUITE LIKELY. OTHER THAN
COLD...LOW RISK FOR OCEAN EFFECT CONTINUES DEPENDING ON EXACT FLOW
PATTERN.

MON...
STRONG HIGH PRES CRESTS OVER THE REGION...AND ALTHOUGH MODEST
RETURN FLOW WILL DEVELOP LATE MON...THE COLD AIRMASS REMAINS THE
DOMINANT PLAYER. ALTHOUGH NOT AS COLD AS SAT NIGHT AND SUN...TEMPS
ARE LIKELY TO STILL REMAIN WELL BELOW NORMAL...ESPECIALLY IF GOOD
RADIATIONAL COOLING IS OBSERVED LATE SUN NIGHT.

MID NEXT WEEK...
LOTS OF UNCERTAINTY HERE AS STRONG SHORTWAVE MOVES MAINLY S OF
THE REGION...WITH THE SRN STREAM BEING DOMINANT. EXACT PATH OF
ATTENDANT LOW PRES REMAINS DIFFICULT TO RESOLVE AS ENSEMBLES RANGE
FROM A WARM INSIDE RUNNER...TO A HARD HITTING BENCHMARK LOW...TO A
WIDE RIGHT MISS. STILL SOME TIME...BUT THIS WILL BE ONE TO WATCH
AS THE PATTERN LOOKS TO SHIFT BACK...AWAY FROM THE CURRENT COLD
PATTERN TO A WARMER ONE BY THE END OF THE MONTH.

&&

.AVIATION /11Z WEDNESDAY THROUGH SUNDAY/...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /THROUGH THURSDAY/...



TODAY...MODERATE CONFIDENCE.

NOTE...NO MAJOR CHANGES WITH 12Z TAF UPDATE...FORECAST DESCRIPTION
BELOW PROVIDES BEST DETAIL.

A MIXTURE OF VFR TO MVFR CIGS EARLY THIS MORNING SHOULD BECOME
MAINLY MVFR AFTER 12Z AND CONTINUE THROUGH THE AFTERNOON.
OTHERWISE...WE WILL BE WATCHING AN AREA OF SCATTERED SNOW SHOWERS
WHICH SHOULD WORK INTO WESTERN MA/NORTHERN CT THROUGH 12Z. THIS
SCATTERED ACTIVITY SHOULD SPREAD ACROSS THE REST OF THE REGION
THROUGH EARLY AFTERNOON. A FEW OF THE SNOW SHOWERS WILL BE BRIEFLY
HEAVY...POSSIBLY RESULTING IN BRIEF IFR TO LIFR CONDITIONS AND
QUICKLY COVERING AIRPORT RUNWAYS. THE BULK OF THE ACTIVITY SHOULD
EXIT THE COASTAL PLAIN BY AROUND 00Z.

TONIGHT...MODERATE TO HIGH CONFIDENCE.  MAINLY VFR CONDITIONS...BUT
WILL HAVE TO WATCH FOR SOME SCATTERED SNOW SHOWERS DEVELOPING ACROSS
SOUTHWEST MA/NORTHERN CT TOWARDS 12Z THURSDAY.

THURSDAY...MODERATE TO HIGH CONFIDENCE.  MAINLY VFR CONDITIONS BUT
SCATTERED FLURRIES/SNOW SHOWERS MAY RESULT IN BRIEFLY LOWER
CONDITIONS.  NORTHWEST WINDS WILL LIKELY GUST TO AROUND 30 KNOTS
BY AFTERNOON BEHIND A STRONG COLD FRONT.

KBOS TERMINAL...MODERATE CONFIDENCE IN TAF TODAY.  BIGGEST
UNCERTAINTY IS THE TIMING OF ANY SCATTERED SNOW SHOWERS WHICH MIGHT
BE BRIEFLY HEAVY...RESULTING IN POOR VISIBILITY.  HIGHEST RISK FOR
THAT IS BETWEEN 17Z AND 23Z.

KBDL TERMINAL...MODERATE CONFIDENCE IN TAF TODAY. SCATTERED SNOW
SHOWERS SHOULD OVERSPREAD THE AREA BY 12Z AND MAY COAT RUNWAYS. THE
RISK FOR SCATTERED SNOW SHOWERS...A FEW OF WHICH MAY BE BRIEFLY
HEAVY WILL CONTINUE INTO THE AFTERNOON.

OUTLOOK /THURSDAY NIGHT THROUGH SUNDAY/...

THU NIGHT INTO FRI...HIGH CONFIDENCE.
MAINLY VFR AFTER AN SHSN DISSIPATE THU EVENING. W WINDS GUST 25-30
KT POSSIBLE THU NIGHT...BUT LIGHTER FRI.

FRI NIGHT INTO SUN...
MAINLY VFR INLAND...BUT SOME OCCASIONAL MVFR/IFR POSSIBLE
ESPECIALLY OVER CAPE COD DUE TO OCEAN EFFECT CLOUDS AND POSSIBLE
SHSN. GUSTY WINDS EXPECTED AT TIMES...20-30 KT POSSIBLE ALONG WITH
VERY COLD CONDITIONS.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /THROUGH THURSDAY/...

TODAY...HIGH CONFIDENCE.  SOUTHWEST WINDS GUSTS WILL GENERALLY
REMAIN LESS THAN 20 KNOTS TODAY. HOWEVER...SOUTH TO SOUTHEAST SWELL
WILL KEEP SEAS BETWEEN 3 AND 6 FEET ACROSS OUR OUTER-WATERS AND
WESTERN SOUNDS TODAY...SO SMALL CRAFT HEADLINES WILL CONTINUE.

TONIGHT...HIGH CONFIDENCE.  WESTERLY WIND GUSTS OF 20 TO 25 KNOTS
EXPECTED ON THE OPEN WATERS ALONG WITH 3 TO 6 FOOT SEAS.  SCA
HEADLINES REMAIN IN EFFECT.

THURSDAY...MODERATE TO HIGH CONFIDENCE.  STRONG COLD FRONT WORKS
ACROSS THE REGION AND WIND GUSTS WILL INCREASE TO NEAR 35 KNOTS
DURING THE AFTERNOON AND EVENING.  THIS IS SUPPORTED BY SOUNDINGS
AND 850T DROPPING TO NEAR -20C.  GALE WATCHES HAVE BEEN ISSUED
THURSDAY AFTERNOON AND EVENING FOR OUR OPEN WATERS WITH SCA
HEADLINES FOR BOSTON HARBOR/NARR BAY.

OUTLOOK /THURSDAY NIGHT THROUGH SUNDAY/...

THU NIGHT...HIGH CONFIDENCE.
GALE FORCE WINDS WILL GRADUALLY DISSIPATE THROUGH THE EVENING
HOURS...GIVING WAY TO SMALL CRAFT THRESHOLD WINDS AND SEAS BY
EARLY MORNING. SOME LIGHT FREEZING SPRAY IS POSSIBLE.

FRI AND FRI NIGHT...HIGH CONFIDENCE.
BRIEF PERIOD OF HIGH PRES WILL LEAD TO CONDITIONS DROPPING BELOW
SMALL CRAFT THRESHOLDS BRIEFLY. OTHERWISE COLD CONDITIONS.

SAT AND SUN...MODERATE CONFIDENCE.
NW WINDS MAY GUST TO GALE FORCE AT TIMES EACH DAY...BUT ESPECIALLY
SAT. THIS WILL BE ACCOMPANIED BY COLD AIR AND THE POTENTIAL FOR
FREEZING SPRAY...WHICH COULD BE MODERATE AT TIMES. EVEN IF WINDS
DON/T FULLY REACH GALE FORCE...SMALL CRAFT CONDITIONS ARE EXPECTED
AS SEAS BUILD AND APPROACH 6-9 FT.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...GALE WATCH FROM THURSDAY AFTERNOON THROUGH LATE THURSDAY NIGHT
     FOR ANZ231>235-237-250-251-254>256.
     SMALL CRAFT ADVISORY FROM 10 AM TO 10 PM EST THURSDAY FOR
     ANZ230-236.
     SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR ANZ235-
     237-250-254>256.
     SMALL CRAFT ADVISORY UNTIL 7 AM EST THIS MORNING FOR ANZ251.

&&

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


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