Area Forecast Discussion
Issued by NWS Boston, MA

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000 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/...
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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.
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&& .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/...
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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.
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&& .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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