Area Forecast Discussion
Issued by NWS Boston, MA

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FXUS61 KBOX 261139
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
739 AM EDT TUE MAY 26 2015

.SYNOPSIS...
WARM AND MUGGY CONDITIONS WILL INCREASE TODAY AND INTO TOMORROW.
SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED EACH DAY...WITH
WEDNESDAY AND THURSDAY HAVING THE HIGHER POTENTIAL FOR STRONG
STORMS.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
740 AM UPDATE...

OVERALL TREND IN THE FORECAST REMAINS ON TRACK AS WARM FRONT
CONTINUES TO PUSH ACROSS NH AND MAINE. GUSTY SOUTHWEST WINDS
ALREADY STARTING TO DEVELOP THIS MORNING AS MIXING GETS UNDERWAY.
ONLY MADE MINOR TWEAKS TO BRING NEAR-TERM CONDITIONS BACK IN LINE
WITH OBSERVED TRENDS.

TODAY...

BERMUDA HIGH CONTINUES TO BUILD UPPER LEVEL RIDGE ACROSS THE REGION
TODAY. DESCENT AMOUNT OF WARM AIR ADVECTION WILL KEEP CLOUDS AROUND
AS HIGH TEMPS WARM INTO THE MID TO UPPER 80S AWAY FROM THE SOUTH
COAST. GUSTY SOUTHWESTERLY WINDS WILL STREAM THE STABLE MARITIME
AIR ACROSS THE SOUTH COAST OF RI AND MASS...INCLUDING THE CAPE AND
ISLANDS KEEPING TEMPS INTO THE 70S.

OTHERWISE THE FOCUS IS TURNED TO THE POTENTIAL FOR SHOWERS AND
THUNDERSTORMS FOR TODAY. WEAK MID-LEVEL SHORTWAVE WILL PASS NORTH OF
THE REGION THIS AFTERNOON/EVENING WHICH COULD TRIGGER A FEW SHOWERS
AND/OR THUNDERSTORMS. HAVE A LOW CONFIDENCE AS TEMPS ALOFT REMAIN
WARM AND HEIGHTS DROP ONLY SLIGHTLY....LIMITING POTENTIAL AND
COVERAGE. HOWEVER WE DO HAVE PLENTY OF MOISTURE BUT INSTABILITY
WILL BE MARGINAL AS CLOUDS WILL LIMIT HEATING TODAY...YET WE STILL
COULD SEE CAPE VALUES NEAR 1000 J/KG. BELIEVE LOCATIONS WEST TO
THE REGION WILL SEE THE BULK OF THE ACTIVITY AS SOUTHERN NEW
ENGLAND MAY SEE JUST A FEW POP-UP SHOWERS. BEST LOCATIONS FOR THE
POTENTIAL WILL BE ACROSS NORTHERN CT AND WESTERN MASS.

&&

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

WARM...MUGGY CONDITIONS WILL CONTINUE OVERNIGHT AS SOUTHERLY FLOW
CONTINUE TO BRING IN HIGHER DEWPOINTS. THE POTENTIAL FOR FOG WILL BE
ON THE INCREASE ESPECIALLY ACROSS THE SOUTH COAST...CAPE AND THE
ISLAND AS 60F DEWPOINTS STREAM OVER THE COOLER OCEAN. IN FACT WE
COULD SEE LOCALLY DENSE FOG BUT BECAUSE OF THE UNCERTAINTY...HELD
OFF ON DENSE FOG ADVISORY.

ANY LEFT OVER CONVECTION ACROSS NEW YORK WILL HAVE THE POTENTIAL TO
MOVE OVER SOUTHERN NEW ENGLAND IN A WEAKEN STATE OVERNIGHT. SEVERAL
GUIDANCE MEMBERS SUGGEST THIS WILL OCCUR BUT SPLIT ON WHERE THIS
WILL OCCUR. THE NAM SAYS THE BULK OF THE SHOWERS WILL BE ACROSS THE
SOUTH COAST WHILE THE GFS/EC SHOWS THAT THE POTENTIAL WILL BE
ACROSS THE MASS PIKE. BECAUSE OF THE UNCERTAINTY KEPT SLIGHT CHC
ACROSS MUCH OF THE REGION.

TOMORROW...

WARM...MUGGY CONDITIONS CONTINUE INTO TOMORROW. SOUTHERLY FLOW WILL
BE A TAD STRONGER KEEPING TEMPS ALONG THE SOUTH COAST IN THE 70S
WHILE THE INTERIOR WARMS INTO THE MID 80S. SOUTHWESTERLY WIND GUSTS
WILL GUST BETWEEN 20-30 KTS.

COULD SEE LINGERING SHOWERS IN THE MORNING HOURS...BUT CLOUDS SHOULD
BREAK DURING THE AFTERNOON. UPPER LEVEL RIDGE SHOULD DOMINATE THE
REGION THROUGH MUCH OF THE DAY AS A COLD FRONT SLOWLY WORKS IT WAY
EASTWARD. FEEL WEDNESDAY HAS THE BETTER POTENTIAL TO SEE A FEW
STRONG THUNDERSTORMS WITHIN THE PRE-FRONTAL TROUGH AND MODEST
SOUTHERLY FLOW...ESPECIALLY ACROSS CT AND WESTERN MA. ASIDE FROM THE
ABUNDANT MOISTURE...CAPE VALUES WILL RANGE BETWEEN 1500-2000 J/KG
WITH ABOUT 25 KTS OF SHEAR. PWAT VALUES WILL BE ABOUT 1.6 INCHES
COMBINED WITH A DESCENT SOUTHERLY LLJ AND WARM CLOUD PROCESSES PER
BUFKIT SOUNDINGS...ANY THUNDERSTORM HAS THE POTENTIAL TO PRODUCE
VERY HEAVY RAIN. HAVE ADDED ENHANCED WORDING FOR HEAVY RAINFALL TO
THE FORECAST. COULD SEE SOME STRONG WINDS GUSTS BUT BELIEVE HEAVY
RAIN IS THE MAIN THREAT.

FOG WILL BEGIN TO REDEVELOP ALONG THE SOUTH COAST BY THE EVENING
HOURS LIMITING VISIBILITIES.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
OVERVIEW AND MODEL PREFERENCES...
OVERALL PATTERN REMAINS THE SAME...AND VERY SUMMER-LIKE. BERMUDA
HIGH PRESSURE OFFSHORE...WITH A DEEP RIDGE ALONG THE EAST COAST...
SHOULD MEAN PLENTY OF OPPORTUNITIES FOR WARMER WEATHER THIS WEEK.
A FRONTAL BOUNDARY GETS CLOSER TO OUR REGION LATE THIS WEEK AND
WEEKEND...ALTHOUGH TIMING VARIES SOME AMONGST THE MODELS. WITH A
HIGH PRESSURE OFFSHORE...AND THIS BOUNDARY BECOMING NEARLY
PARALLEL TO THE MID-LEVEL FLOW...AM NOT EXPECTING A CLEAN FRONTAL
PASSAGE. WILL FAVOR THE CONSENSUS SOLUTION TIMING FOR NOW...AND
LEAVE THE WINDOW FOR ANY POTENTIAL FRONT RATHER BROAD.

DETAILS...

WEDNESDAY NIGHT...MAY SEE AREAS OF FOG DEVELOP...WHICH COULD BE
LOCALLY DENSE...ALONG THE IMMEDIATE S AND SE COASTS AS DEWPOINTS
CONTINUE TO SLOWLY RISE.

THURSDAY...FRONTAL BOUNDARY WASHES OUT BUT STILL SOME INSTABILITY
LINGERING WITH SOUPY AIRMASS ACROSS THE REGION. INSTABILITY
PARAMETERS NOT QUITE AS STRONG AS ON WED...AND STRONGEST WINDS ARE
FARTHER NORTH...BUT STILL DECENT BY NEW ENGLAND STANDARDS. SO WE
COULD SEE A FEW STRONG STORMS AS MID LAYER STARTS TO COOL A BIT
LENDING TO ELEVATED INSTABILITY. SOMEWHAT LOWER PWATS...AROUND 1.5
INCHES...BUT STILL ENOUGH WITH THE HIGH DEWPOINTS FOR HEAVY
RAINFALL FROM ANY CONVECTION. EXPECTING AREAS OF FOG TO REDEVELOP
ALONG S COASTAL AREAS THU NIGHT INTO FRI MORNING.

FRIDAY...WHILE ANOTHER BOUNDARY TENDS TO WEAKEN OVER THE REGION...
NOT A WHOLE LOT OF FORCING OVER OUR REGION DURING THIS TIMEFRAME.
HOWEVER...STILL CANNOT RULE OUT A FEW DIURNAL SHOWERS/TSTMS. ONE
MORE ROUND OF FOG LOOKS TO DEVELOP ALONG THE COAST MAINLY FROM
COASTAL PLYMOUTH COUNTY SOUTHWARD.

SATURDAY...MODELS BEGIN TO DIVERGE ON THEIR SOLUTIONS AS ANOTHER
FRONT TRIES TO SLIP SE OUT OF SOUTHERN QUEBEC. LOOKS LIKE MORE
DIURNAL SHOWERS/TSTMS DURING THE AFTERNOON/EVENING ACROSS INLAND
AREAS.

SUNDAY-MONDAY...TIMING DIFFERENCES WITH THE APPROACHING FRONT LEND
TO LOW CONFIDENCE DURING THIS TIMEFRAME. IN ANY EVENT...HAVE MORE
CHANCES FOR SHOWERS/THUNDERSTORMS FOR SUNDAY AS A FRONT LOOKS TO
SLOWLY PUSH ACROSS THE REGION...THEN STALLING NEAR OR JUST OFF THE
SOUTH COAST MONDAY...WITH LOWER CHANCE FOR SHOWERS. MAY SEE DRIER
AIR WORK INTO NORTHERN MA DURING MONDAY AFTERNOON.

&&

.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /THROUGH WEDNESDAY/...HIGH CONFIDENCE.

TODAY...VFR. CHANCE OF A TSTM WITH MVFR VSBYS/CIGS ACROSS
CT/PIONEER VALLEY THIS AFTERNOON. IFR STRATUS AND FOG WILL
INCREASE ACROSS SOUTH COAST LATE AFTERNOON/EVENING.

TONIGHT...VFR DETERIORATING TO MVFR/IFR IN AREAS OF FOG
PARTICULARLY ALONG THE SOUTH COAST...CAPE...AND ISLANDS. COULD SEE
PASSING SHOWER/TSTORM OVERNIGHT.

WEDNESDAY...IFR ALONG THE SOUTH COAST DURING THE MORNING SHOULD
PUSH OFFSHORE. ANTICIPATE VFR CONDITIONS ACROSS THE
INTERIOR...DROPPING TO MVFR WITHIN ANY -SHRA/-TSRA THAT DEVELOPS.
EXPECT SW WINDS TO GUST UP TO 20-25 KT AT TIMES MAINLY ACROSS
RI/SE MA WED AFTERNOON/EVENING.

KBOS TERMINAL...HIGH CONFIDENCE IN TAF.

KBDL TERMINAL...HIGH CONFIDENCE IN TAF. COULD SEE CONDITIONS DROP
TO MVFR WITHIN A POP-UP THUNDERSTORM TODAY.

OUTLOOK...WEDNESDAY NIGHT THROUGH SATURDAY...MODERATE CONFIDENCE.

WEDNESDAY NIGHT...AREAS OF FOG DEVELOP WED NIGHT WITH MVFR-IFR
VSBYS. MAY SEE PATCHY LIFR CIGS/VSBYS WITH OCEAN CLOUDS/DENSE FOG
ALONG THE IMMEDIATE S AND SE COASTS OVERNIGHT.

THURSDAY AND FRIDAY...EXPECT CHANCE FOR -SHRA/TSRA WITH LOCAL
MVFR-IFR CONDITIONS. WILL ALSO SEE AREAS OF FOG DEVELOP EACH LATE
NIGHT/EARLY MORNING PERIOD WITH IFR-LIFR VSBYS.

SATURDAY...PATCHY FOG EARLY SAT MORNING WITH MVFR-IFR CONDITIONS
WILL IMPROVE. SCT SHRA/TSRA SAT THROUGH SAT NIGHT WITH LOCAL
MVFR-IFR CONDITIONS.

SUNDAY...S-SW WINDS WILL GUST UP TO 25 KT AT TIMES SAT AFTERNOON/
EVENING...MAINLY ALONG THE S COAST...CAPE COD AND THE ISLANDS.
SCT SHOWERS/ISOLD TSTMS MAY LINGERING THROUGH SUNDAY...BUT SHOULD
END SUN NIGHT. MAY SEE BRIEF MVFR CONDITIONS.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /THROUGH WEDNESDAY/...HIGH CONFIDENCE.

SOUTHWESTERLY FLOW WILL CONTINUE THROUGH THE PERIOD. THIS WILL
HELP BUILD SEAS AND SWELL ACROSS THE SOUTHERN WATERS BY TONIGHT
AND TOMORROW. OTHERWISE EXPANDED THE SCA FOR NEAR SHORE WATERS AS
GUSTS WILL REACH 25KTS DURING THIS AFTERNOON. IN ADDITION...AREAS
OF FOG ARE LIKELY TO DEVELOP TONIGHT...REDUCING VISIBILITIES.

OUTLOOK...WEDNESDAY NIGHT THROUGH SATURDAY...MODERATE CONFIDENCE.

S-SW WINDS REMAIN PERSISTENT WITH GUSTS UP TO AROUND 20 KT...
MAINLY THU INTO THU NIGHT. SEAS LINGERING AT AROUND 5 FT ACROSS
THE SOUTHERN OPEN WATERS THROUGH THU...THEN SHOULD SUBSIDE. VSBYS
REDUCED IN AREAS OF FOG...LOCALLY DENSE OFFSHORE BOTH THU AND FRI
NIGHTS.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR
     ANZ231>234.
     SMALL CRAFT ADVISORY UNTIL 6 AM EDT WEDNESDAY FOR ANZ235-250-
     254>256.

&&

$$
SYNOPSIS...BELK/DUNTEN
NEAR TERM...BELK/DUNTEN
SHORT TERM...DUNTEN
LONG TERM...BELK
AVIATION...BELK/DUNTEN
MARINE...BELK/DUNTEN


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