Area Forecast Discussion
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000
FXUS61 KBOX 231200
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
700 AM EST SUN NOV 23 2014

.SYNOPSIS...
DRY AND MILD TODAY. A WARM FRONT WILL BRING A BRIEF PERIOD OF
HEAVY RAIN AND GUSTY SOUTH WINDS ALONG THE COAST LATE TONIGHT AND
MONDAY MORNING FOLLOWED BY UNSEASONABLY MILD CONDITIONS MONDAY
AFTERNOON. GUSTY WINDS BUT DRIER WEATHER FOLLOWS FOR TUESDAY. A
COASTAL STORM MAY BRING SOME MIXED PRECIPITATION TO THE REGION
WEDNESDAY INTO THANKSGIVING DAY...BUT THERE IS A LOT OF
UNCERTAINTY. COLDER WEATHER FOLLOWS LATE IN THE WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
7 AM UPDATE...
LAST FEW SHOWERS ASSOCIATED WITH MODEST LLJ AND WARM FRONTAL
CONVERGENCE MOVING THROUGH AND DISSIPATING THIS HOUR ACROSS
CT/RI/SE MA. THESE SHOULD COME TO AN END IN THE NEXT COUPLE OF
HOURS. OTHERWISE...LITTLE OTHER CHANGES TO THE FORECAST THIS
MORNING AS OTHER PARAMETERS ARE ON TRACK...INCLUDING TEMPS/DWPTS.

SCT SHOWERS ARE MOVING ACROSS THE REGION EARLY THIS MORNING...MAINLY
ALONG AND NORTH OF THE MASS PIKE. TEMPS ARE MOSTLY ABOVE FREEZING
IN THE MID/UPPER 30S SO PTYPE IS RAIN...BUT A FEW LOCATIONS IN W
MA REPORTING 32-33 DEGREES PER MESONET SO CANT RULE OUT AN
ISOLATED POCKET OF LIGHT FREEZING RAIN...MAINLY BERKSHIRES. PRECIP
WILL END BY DAYBREAK. FURTHER SOUTH...DRY WEATHER WILL PREVAIL AS
LOW LEVELS ARE CONSIDERABLY DRIER.

FOR TODAY...WEAK SFC AND MID LEVEL RIDGING BUILDS ACROSS THE
REGION TODAY WHICH WILL BRING DRY CONDITIONS. THERE IS ENOUGH MID
LEVEL DRYING FOR SOME PARTIAL SUNSHINE TO DEVELOP WHICH WILL LEAD
TO A MILD AFTERNOON. 2M TEMPS SUGGEST MAX TEMPS WILL REACH THE LOW
TO MID 50S...WITH UPPER 40S IN THE INTERIOR HIGH TERRAIN. 925 MB
TEMPS 8-10C SO THERE IS A CHANCE TEMPS COULD BE EVEN MILDER IF
THERE IS ENOUGH SUNSHINE.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
***BRIEF PERIOD OF HEAVY RAIN VERY LATE SUN NIGHT/MON MORNING
  IMPACTING THE AM RUSH HOUR***

DRY WEATHER EXPECTED THROUGH MIDNIGHT. LOW PRES MOVES INTO THE GT
LAKES LATE TONIGHT WITH A WARM FRONT APPROACHING FROM THE S. GOOD
ISENTROPIC LIFT ENHANCED BY A STRONG LOW LEVEL JET WILL BRING A
PERIOD OF HEAVY RAINFALL LATE TONIGHT INTO MON MORNING. GEFS
SHOWING PWAT ANOMALY INCREASING TO +3SD AND LOW LEVEL JET REACHES
+4SD IN SNE AROUND 12Z MON SO THIS IS A GOOD SIGNAL FOR HEAVY
RAIN. HOWEVER...THE SYSTEM IS QUITE PROGRESSIVE AND WE ARE ONLY
LOOKING AT ABOUT A 6 HOUR PERIOD OF HEAVY RAIN BEFORE TAPERING
OFF BY MIDDAY MONDAY. THIS WILL LIMIT RAINFALL AMOUNTS TO
0.50-1.00" WITH LOCALLY HIGHER AMOUNTS. MAIN THREAT IS TYPICAL
MINOR POOR DRAINAGE FLOODING BUT THIS WILL BE OCCURRING DURING
THE MORNING COMMUTE. ELEVATED INSTABILITY PARAMETERS ARE NOT THAT
IMPRESSIVE BUT CANT RULE OUT AN ISOLD TSTM IN THE COASTAL PLAIN
MON MORNING AT THE NOSE OF THE LOW LEVEL JET.

THE OTHER CONCERN IS POTENTIAL FOR STRONG WINDS MONDAY MORNING
ALONG THE SOUTH COAST. NAM IS MOST ROBUST WITH THE LOW LEVEL
NEARING 75 KT AT 925 MB WHILE GFS/ECMWF SHOWING 65-70 KT.
SOUNDINGS SHOW A GOOD INVERSION WHICH WILL LIMIT THESE WINDS FROM
MIXING DOWN. A FINE LINE OF CONVECTION WHICH COULD HELP TO BRING
DOWN THESE WINDS TO THE SFC IS NOT LIKELY AS INSTABILITY IS
MARGINAL AND THERE IS NOT A COLD FRONT WHICH TYPICALLY PROVIDES A
FOCUS FOR THESE FINE LINES. TAKING ABOUT 50 PERCENT OF THE JET
SUGGESTS WIND GUSTS COULD PEAK AT 40-45 MPH WHICH IS NEAR WIND
ADVISORY CRITERIA. BEST CHANCE OF REACHING ADVISORY CRITERIA WILL
BE ACROSS CAPE/ISLANDS.

BULK OF THE RAIN IS OVER BY MON AFTERNOON...EARLIER IN WESTERN
NEW ENG...BUT CANT RULE OUT A FEW AFTERNOON SHOWERS AND LOW CLOUDS
WILL LIKELY PERSIST THROUGH THE DAY. IT WILL BE UNSEASONABLY MILD
WITH HIGHS WELL INTO THE 60S IN MANY LOCATIONS AND DEWPOINTS WILL
APPROACH 60 WITH GUSTY S/SW WINDS TO 30-35 MPH IN THE COASTAL
PLAIN. 925 MB TEMPS ARE QUITE MILD NEAR +15C WHICH WOULD NORMALLY
SUPPORT HIGHS IN THE LOWER 70S BUT THINK LOW CLOUDS WILL LIMIT
HEATING. IF WE CAN GET ANY SUN...70+ WOULD BE POSSIBLE.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
HIGHLIGHTS...

* MILD BUT WINDY ON TUESDAY
* COASTAL STORM WITH TRAVEL IMPACTS POSSIBLE WED-THU WITH UNCERTAINTY
* COLDER WEATHER BY THE END OF THE WEEK

OVERVIEW AND MODEL PREFERENCES...
23.00Z MODEL GUIDANCE SUITE CONTINUES TO SHOW MODERATE AGREEMENT
THROUGH THE MID TERM PERIOD...INCLUDING THE REDEVELOPMENT OF DEEP
LONGWAVE TROF BY MID- LATE WEEK ACROSS THE ERN THIRD OF THE CONUS.
THE PRIMARY MODEL ISSUES AND DISAGREEMENTS ARE STILL REGARDING THE
POTENTIAL COASTAL STORM FOR LATE WED-THU. THIS DISAGREEMENT IS
LIKELY DUE TO THE FACT THAT THE EJECTING SHORTWAVE ASSOCIATED WITH
THE FRONTAL WAVE DEVELOPMENT IS STILL WRAPPED IN THE NEAR
ALEUTIAN ISLANDS LOW...AND MAY NOT BE BETTER SAMPLED FOR ANOTHER
24+ HOURS. AGREE WITH WPC...THE KEY WILL BE WHERE THE LOW PASSES
IN REGARD TO THE 40/70 BENCHMARK...WITH THE GFS LEANING ABOUT
50-100 NM E AND THE ECMWF CLOSER TO BUT W OF IT. ECENS MEAN SEEMS
TO SPLIT THIS DIFFERENCE WELL...AND GIVEN WPC/S PREFERENCE FOR IT
AS WELL...WILL LEAN THERMAL PROFILES WITH THIS UPDATE CLOSER TO
IT/S THINKING...ALTHOUGH ESSENTIALLY THIS IS CLOSE TO A GFS/ECMWF
BLEND IN SPITE OF THE FACT THE ECMWF IS WELL W OF THE BENCHMARK.
GIVEN THE UNCERTAINTY WITH THE STORM ITSELF...HOW EFFICIENTLY IT
IS ABLE TO DRAW IN THE COLDER AIR FROM THE LONGWAVE TROF TO THE W
REMAINS STILL A BIT OF A QUESTION MARK TOWARD THE END OF THE
WEEK...BUT A TREND TOWARD COLDER CONDITIONS LOOKS LIKELY.

DETAILS...

MON NIGHT INTO TUE NIGHT...
MAINLY DRY FORECAST HERE ALTHOUGH A FEW LINGERING SHOWERS ARE
POSSIBLE MAINLY MON NIGHT AS UPPER LVL SHORTWAVE PIVOTS THROUGH
ALONG WITH WEAKENING COLD FRONT. COLD AIR REMAINS TO THE W AND SO
IN SPITE OF COLD ADVECTION W-FLOW...EXPECT TEMPS TO REMAIN NEAR TO
EVEN SLIGHTLY ABOVE NORMAL.

WED INTO THU...
AS MENTIONED ABOVE...THERE IS STILL TOO MUCH UNCERTAINTY HERE FOR
A HIGH CONFIDENCE FORECAST EVEN WITH THE POTENTIAL IMPACTS AT
PLAY. IN ANY CASE...DO HAVE CONFIDENCE IN A MORE RAPIDLY DEEPENING
COASTAL LOW PRES MOVING OUT OF THE MID ATLANTIC TO THE SE MA
COASTLINE...MAKING IT/S CLOSEST PASS ESPECIALLY WED
NIGHT...DIPPING BELOW 1000MB. THE EXACT TRACK IS THE MAIN QUESTION
AND AS SUCH...WHAT THE THERMAL PROFILE IS MOST LIKELY TO LOOK
LIKE. AT THIS TIME...0C H92 LINE VARIES BETWEEN JUST W OF THE BOS-
PVD CORRIDOR TO OFFSHORE...SO EXACTLY WHERE ANY RAIN/SNOW LINE
DEVELOPS REMAIN IN FLUX. GIVEN THE DYNAMICS AS POINTED OUT BY THE
PREVIOUS FORECASTER...WETBULB/DYNAMIC COOLING ARE LIKELY TO LEAD
TO COOLER TEMPS THAN THE STRAIGHT 2M MODEL TEMPS WOULD
INDICATE...SO EVEN WITH THE FURTHER E TRACK...SNOW IS POSSIBLE.
HOW MUCH IS JUST TOO UNCERTAIN TO CALL GIVEN NOT JUST THE THERMAL
PROFILE ISSUES... THERE IS A BANDING SIGNAL AND TROWAL SIGNATURE
TOWARD THE NE QUADRANT. WHICH COULD PROVIDE DYNAMIC COOLING.

WHAT THIS ALL MEANS IS THAT THERE IS THE CHANCE FOR A COASTAL
STORM...WITH WINTERY PRECIP AND POSSIBLY EVEN PLOWABLE SNOW
DEPENDING ON THE FINAL TRACK FOR THE WED AFTERNOON INTO EARLY
THANKSGIVING MORNING TIMEFRAME.  EXACTLY HOW MUCH SNOW AND WHERE
RAIN/SNOW LINE SETS UP REMAINS IN QUESTION. BUT PRECIP IS LIKELY TO
LEAN E GIVEN SIGNALS FOR HEAVY RAIN ON THE RAIN SIDE AS WELL AS
GUSTY WINDS IF THE TRACK IS CLOSER.  COULD ALSO BE SIGNIFICANT
GRADIENT BETWEEN WRN MA/CT/NH AND EARN MA/RI IN SNOW/RAINFALL.
ALSO...AS MENTIONED BY PREVIOUS FORECASTER...COASTAL FLOODING THREAT
APPEARS RELATIVELY LOW GIVEN THE RAPID MOVEMENT /LACK OF DOWNSTREAM
BLOCKING/ AND LOW ASTRONOMICAL TIDES. ALL THESE FEATURES WILL HAVE
TO BE WATCHED GIVEN THEY WILL BEGIN DURING A VERY BUSY TRAVEL PERIOD
ON WED.

FRI...
COLDER AIR BEGINS TO BUILD IN BEHIND THE EXITING LOW
PRES...EXPECT A TREND TOWARD DRIER BUT COLDER WEATHER BY LATE IN
THE WEEK.

NEXT WEEKEND...
AS CORE OF COLD AIR TROF BEGINS TO MOVE OVER...EXPECT TEMPS BELOW
NORMAL...AND POSSIBLY EVEN A WEAK WAVE OF LOW PRES/CLIPPER.

&&

.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...

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

SHORT-TERM /THROUGH MONDAY/...

THROUGH 12Z...MAINLY VFR CIGS WITH POCKETS OF MVFR BERKSHIRES AND
MONADNOCKS. SCT SHOWERS MOVING ACROSS W AND CENTRAL MA WITH ISOLD
-FZRA IN THE BERKSHIRES. SW GUSTS TO 35 KT CAPE/ISLANDS WILL BE
DIMINISHING THROUGH 12Z. AREAS OF LLWS POSSIBLE...MAINLY IN THE
CT VALLEY WHERE SFC WINDS SOUTH AND 2K WINDS WEST AROUND 40 KT.

TODAY...HIGH CONFIDENCE. VFR.

TONIGHT INTO MONDAY...MODERATE CONFIDENCE.

DETERIORATING CONDITIONS TO MVFR-IFR AS WIDESPREAD RAIN...LOCALLY
HEAVY MOVES WEST TO EAST ACROSS THE REGION...BEGINNING AROUND 06Z
CT VALLEY AND REACHING E COAST BY 10Z. ISOLD TSTM POSSIBLE MON
MORNING NEAR THE SOUTH COAST. RAIN TAPERS OFF 12-16Z W TO E BUT
IFR CIGS WILL LIKELY PERSIST THROUGH THE DAY ALONG WITH PATCHY
FOG AS HIGHER DEWPOINTS MOVE IN. A PERIOD OF S WIND GUSTS TO
30-40 KT POSSIBLE 12-16Z MON ALONG THE S COAST AND ESPECIALLY
CAPE/ISLANDS...THEN SW GUSTS TO 30 KT COASTAL PLAIN IN THE
AFTERNOON. LLWS WILL ALSO BE A CONCERN LATE TONIGHT CT VALLEY
SHIFTING TO SE NEW ENG MON MORNING AS SOUTHERLY LOW LEVEL JET
50-60 KT DEVELOPS AT 2K FT.

KBOS TERMINAL...HIGH CONFIDENCE.

KBDL TERMINAL...HIGH CONFIDENCE. SHOWERS MAINLY N OF TERMINAL.
LLWS POSSIBLE EARLY THIS MORNING.

OUTLOOK...MONDAY NIGHT THROUGH THURSDAY.

MON NIGHT INTO TUE NIGHT...MODERATE CONFIDENCE.  MAINLY VFR. BUT A
FEW LEFTOVER SHOWERS POSSIBLE MON NIGHT ESPECIALLY MAY YIELD MVFR
CONDITIONS.  W-SW WIND GUSTS ABOUT 20-25 KT AT TIMES EACH DAY.

WED INTO THU...LOW CONFIDENCE.  A COASTAL LOW PRES WILL MOVE
SOMEWHERE BETWEEN JUST ONSHORE OF SE MA OR OFFSHORE.  GIVEN THIS
UNCERTAINTY IN TRACK...THERE IS UNCERTAINTY IN SNOW/RAIN
POTENTIAL...BUT THERE IS THE POSSIBILITY OF EACH WITH ACCUMULATIONS
OF SNOW. NE WINDS COULD ALSO GUST 25+ OR MORE EITHER DAY.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /THROUGH MONDAY/...

TODAY...HIGH CONFIDENCE.

SW GUSTS 25-30 KT SE WATERS EARLY...OTHERWISE DIMINISHING WIND
THROUGH THE MORNING WITH GUSTS DROPPING BELOW SCA THRESHOLDS THIS
AFTERNOON.

TONIGHT AND MONDAY...MODERATE CONFIDENCE.

DEVELOPING LOW LEVEL JET WILL RESULT IN GUSTY S WINDS LATE TONIGHT
INTO MONDAY. THERE IS AN INVERSION OVER THE WATERS WHICH WILL
LIKELY LIMIT GUSTS AND PREVENT STRONG WINDS FROM MIXING
DOWN. HOWEVER GIVEN STRENGTH OF THE JET...GALE FORCE GUSTS TO
35-40 KT SEEM PLAUSIBLE AND GALE WARNINGS MAY BE NEEDED. SEAS
WILL LIKELY BUILD TO BETWEEN 10 AND 15 FEET ACROSS THE SOUTHERN
WATERS WITH VERY LONG FETCH.

OUTLOOK...MONDAY NIGHT THROUGH THURSDAY.

MONDAY NIGHT THROUGH TUESDAY NIGHT...HIGH CONFIDENCE. AT LEAST SMALL
CRAFT ADVISORY CONDITIONS WITH WINDS MAINLY SW-W AND GUSTS 25-30 KT
INTO EARLY TUE.  SEAS ALSO AROUND 8-10 FT.  BOTH WINDS AND SEAS DROP
OFF LATE TUE TONIGHT WITH A BRIEF LULL EXPECTED INTO EARLY WED.  LOW
PROBABILITY OF SOME GALE FORCE GUSTS ON TUE.

WED AND THU...LOW CONFIDENCE. A COASTAL STORM WILL PASS SOMEWHERE
NEAR 40N/70W...THIS WILL YIELD BUILDING SWELL AND WINDS SHIFTING
FROM NE LATE WED TO WNW BY LATE THU.  DEPENDING ON HOW CLOSE THE
STORM COMES...HEAVY RAIN AND AT LEAST SMALL CRAFT ADVISORY
CONDITIONS ARE POSSIBLE.  GALES ALSO A POSSIBILITY.  VISIBILITIES
DROP IN RAIN/FOG.

&&

.TIDES/COASTAL FLOODING...
ASTRONOMICAL TIDES ARE FAIRLY HIGH DURING THE MON MORNING HIGH
TIDE CYCLE. WITH SOUTHERLY GALES EXPECTED...A STORM SURGE OF 1-2
FT IS POSSIBLE ALONG THE SOUTH COAST WHICH MAY BRING SOME
LOCATIONS TO MINOR FLOOD. THE MAIN THREAT FOR MINOR COASTAL
FLOODING WILL BE ALONG NARRAGANSETT BAY AND WESTPORT HARBOR DUE
TO SOUTHERLY FETCH. COASTAL FLOOD ADVISORIES MAY EVENTUALLY BE
NEEDED. NO FLOODING IS EXPECTED ALONG THE EAST COAST.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
     ANZ231>235-237.
     SMALL CRAFT ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR ANZ250-
     254>256.

&&

$$
SYNOPSIS...KJC/DOODY
NEAR TERM...KJC/DOODY
SHORT TERM...KJC
LONG TERM...DOODY
AVIATION...KJC/DOODY
MARINE...KJC/DOODY
TIDES/COASTAL FLOODING...


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