Area Forecast Discussion
Issued by NWS Boston, MA

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000 FXUS61 KBOX 251936 AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 336 PM EDT MON MAY 25 2015 .SYNOPSIS...
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WARM AND MUGGY CONDITIONS START TO BUILD IN ALONG WITH AN INCREASING CHANCE OF SHOWERS AND THUNDERSTORMS THROUGH THE END OF THE WEEK. THE THREAT FOR SCATTERED SHOWERS AND THUNDERSTORMS WILL INCREASE FROM LATE WEDNESDAY THROUGH THURSDAY AND AGAIN OVER THE WEEKEND.
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&& .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
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TEMPERATURES HAVE CLIMBED INTO THE UPPER 70S TO LOWER 80S THIS AFTERNOON DESPITE THE THICKENING CLOUD COVER. EXPECT CLOUDS TO LINGER AS THE ATMOSPHERE MOISTENS UP BEHIND THE WARM FRONT. THE WARM FRONT IS CURRENTLY IN THE HUDSON VALLEY IN NEW YORK AND WILL MOVE INTO SOUTHERN NEW ENGLAND THIS EVENING AND THEN NORTH OF THE AREA AFTER MIDNIGHT TONIGHT. THE FRONT WILL KEEP DEWPOINTS IN THE 50S OVERNIGHT WHICH IN TURN WILL KEEP OVERNIGHT TEMPERATURES IN THE UPPER 50S TO LOWER 60S. THERE IS A LOW PROBABILITY OF SHOWERS AND SPRINKLES ALONG THE MA/NH BORDER LATE TONIGHT AS THE WARM FRONT MOVES THROUGH. HOWEVER...MOST OF THE ENERGY AVAILABLE TO PRODUCE SHOWERS REMAINS FARTHER NORTH.
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&& .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
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TUESDAY...A REAL SUMMER-LIKE DAY IS EXPECTED WITH THE WARM FRONT THROUGH THE AREA. EXPECT WARM...MUGGY CONDITIONS WITH TEMPERATURES CLIMBING INTO THE MID TO UPPER 80S ACROSS MUCH OF SOUTHERN NEW ENGLAND. SOUTHWESTERLY WINDS WILL KEEP THE SOUTH COAST OF RI AND MA AS WELL AS THE SOUTHERN SIDE OF CAPE ANN SIGNIFICANTLY COOLER WITH HIGHS IN THE UPPER 60S TO LOWER 70S. MODELS ARE INDICATING SOME INSTABILITY IN THE AFTERNOON. THIS MAY BE ENOUGH TO POP A FEW SCATTERED THUNDERSTORMS IN NORTHWEST CT AND WESTERN MA. SO KEPT THE SLIGHT CHANCE TO CHANCE POPS THERE. NOT EXPECTING ANYTHING IN THE WAY OF PRECIP ACROSS EASTERN MA/RI. TUESDAY NIGHT...THE UPPER RIDGE THAT HAS BEEN IN PLACE ALONG THE EASTERN SEABOARD STARTS TO BREAK DOWN...SHIFTING TO THE EAST. THIS WILL ALLOW BETTER INSTABILITY TO SLOWLY FILTER INTO SOUTHERN NEW ENGLAND. SHOWERS AND THUNDERSTORMS THAT DEVELOP OVER NYS COULD MOVE INTO THE WESTERN PORTIONS OF SOUTHERN NEW ENGLAND OVERNIGHT. HAVE SLIGHT CHANCE TO CHANCE POPS IN PLACE FOR THESE AREAS DURING THE OVERNIGHT PERIOD. CONTINUED SOUTHWESTERLY FLOW WILL KEEP THINGS WARM AND MUGGY. IT/LL BE ANOTHER NIGHT WITH LOWS IN THE 60S.
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&& .LONG TERM /WEDNESDAY THROUGH MONDAY/... */ HIGHLIGHTS... - WARM AND MUGGY CONDITIONS - THREAT OF MARINE STRATUS / FOG ALONG THE S COAST - SHOWER / THUNDERSTORM CHANCES BEGINNING LATE WEDNESDAY - THREAT OF HEAVY RAIN AND POSSIBLE SEVERE WEATHER - POTENTIAL LULL IN ACTIVITY FRIDAY - ANOTHER ROUND OF SHOWERS / THUNDERSTORMS FOR THE WEEKEND */ DISCUSSION... TUESDAY NIGHT - WEDNESDAY NIGHT: RIDGE OF HIGH PRESSURE GRADUALLY DEAMPLIFIES ALLOWING MID-LEVEL ENERGY ALONG WITH LOW- TO MID-LEVEL SW-CONVERGENT FLOW AND RRQ OF AN UPPER-LEVEL JET TO SLINK SE TOWARDS SNE. SHOWERS/THUNDERSTORMS CHANCES INCREASE. INITIAL ACTIVITY LOOKS TO DEVELOP ACROSS PA / UPSTATE NY BY AFTERNOON WITH DAYTIME HEATING. FOCUS APPEARS TO BE ALONG A PRE-FRONTAL BOUNDARY PARALLEL WITH LOW- LEVEL THETA-E/INSTABILITY AXES PRESSING E WITH THE WSW STEERING FLOW INTO N/W NEW ENGLAND LATE INTO THURSDAY MORNING. LIKELY SOME SEVERE TO THE W. OUTCOMES UNCERTAIN FOR HERE. PER BUFKIT CAPPING INVERSION ALONG WITH LOW- TO MID-LEVEL DRY AIR LINGERS. H925-85 SW-FLOW IS DIVERGENT. SHOWER ACTIVITY LIKELY PUSHES E INTO THE FORECAST AREA BUT LOSES ITS PUNCH AS IT DOES SO. SHOWERS POTENTIALLY LINGERING INTO THE FOLLOWING MORNING. WITH ANTICIPATED ELEVATED INSTABILITY THUNDERSTORM ACTIVITY NOT OUT OF THE QUESTION. OTHERWISE... WARM / MUGGY CONDITIONS WITH S-FLOW OF HIGHER DEWPOINT AIR N...THOUGH MID- TO HIGH-LEVEL CLOUD DECKS MAY LIMIT HEATING. MARINE STRATUS / FOG LIKELY TO BE AN ISSUE FOR MUCH OF THE FORECAST PERIOD FOR S/SE- COASTAL COMMUNITIES AS MOISTURE POOLS BENEATH A STOUT WARM-DRY- SUBSIDENCE INVERSION. THURSDAY - THURSDAY NIGHT: MAIN DRIVING FORCE OF MID-LEVEL ENERGY AND ATTENDANT JET-STREAK LIFTS NE RESULTING IN A COOL FRONT PUSHING SE OUT OF CANADA TO BECOME DIFFUSE INTO THE OVERNIGHT HOURS. THIS IN ADDITION TO POSSIBLE CLOUD COVER LEFT-OVER FROM WEDNESDAY PUTS INTO QUESTION OF SHOWER/THUNDERSTORM DEVELOPMENT. THOUGH THE BOUNDARY- LAYER MAY NOT DESTABILIZE...MID-LEVEL COOLING LENDING TO INCREASED ELEVATED INSTABILITY AND THE SUGGESTION OF PERHAPS SOME MID- TO UPPER-LEVEL FORCING /IN ADDITION TO THE CONSENSUS OF DECENT THETA-E AND INSTABILITY AXIS ACROSS SNE/ YIELDS CONTINUED CHANCE SHOWER / THUNDERSTORM THREAT. DECENT SHEAR SO A SEVERE THREAT IS POSSIBLE BUT HAVE GREATER CONFIDENCE TOWARDS A HEAVY RAIN THREAT. PWATS IN EXCESS OF 1.5-INCHES WITH FREEZING LEVEL HEIGHTS OF 11-12 KFT. CONTINUING WITH A WARM-MUGGY THEME WITH RESPECT TO CONDITIONS AS WELL AS MARINE STRATUS / FOG BEING AN ISSUE ALONG THE S/SE-COAST. FRIDAY - FRIDAY NIGHT: DISCREPANCIES AMONG FORECAST GUIDANCE. WHILE THE ENVIRONMENT LOOKS PRIME FOR SHOWER/THUNDERSTORM DEVELOPMENT... NOT A LOT OF FORCING APPARENT. OFFSHORE HIGH PRESSURE LOOKS TO BE INFLUENTIAL AS RIDGING ENHANCES ALOFT EVER SLIGHTLY AHEAD OF A WEEKEND DISTURBANCE. BIGGEST DISCREPANCY CENTERS AROUND MOISTURE AVAILABILITY TO WHICH GFS BUFKIT PROFILES SUGGEST CAN DESTABILIZE. WILL KEEP WITH SLIGHT CHANCE POPS FOR THE PERIOD. WEEKEND - EARLY NEXT WEEK: AGREED UPON THAT ENERGY DIVING S ROUND THE N CANADIAN VORTEX MEETS UP WITH ENERGY OUT OF THE CENTRAL CONUS PUSHING A SURFACE FRONTAL BOUNDARY S ACROSS THE NE CONUS. UNCLEAR AS TO ITS EVOLUTION...WHETHER IT STALLS. FORECAST INTO EARLY NEXT WEEK BECOMES COMPLICATED. OF CERTAINTY IS THAT A PRIMED ENVIRONMENT LOOKS TO EXIST AHEAD OF THE FRONTAL BOUNDARY BENEATH DEEP-LAYER FORCING. THIS SHOULD YIELD LIKELY SHOWER/THUNDERSTORM ACTIVITY. BUT WITH TIMING AND LONGEVITY UNCERTAIN WILL KEEP WITH CHANCE POPS. && .AVIATION /20Z MONDAY 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 TUESDAY/...HIGH CONFIDENCE. 18Z UPDATE... THROUGH 00Z...VFR. SCT-BKN MID-HIGH LEVEL CIGS. SCT SPRINKLES ACROSS THE N-HALF OF S NEW ENGLAND. SW WINDS 10-15 KTS MAY GUST TO 25 KT INTO THIS AFTERNOON. TONIGHT...VFR. MAY SEE PATCHY FOG WITH MVFR VSBYS LATE S COAST/ CAPE COD/ISLANDS. SW WINDS WILL BE UP TO 40 KT AT 1000-2000 FT ABOVE THE SURFACE. NOT QUITE STRONG ENOUGH FOR LOW LEVEL WIND SHEAR TO BE INSERTED INTO TERMINALS...BUT IMPORTANT TO BE AWARE OF. TUESDAY...VFR. COULD STILL HAVE SOME PATCHY MVFR VSBYS IN FOG NEAR THE S COAST...MAINLY EARLY. CHANCE OF A TSTM WITH MVFR VSBYS IN NW CT AND WESTERN MA...INCLUDING BDL/BAF AND IN THE BERKSHIRES LATE IN THE AFTERNOON. TUESDAY NIGHT...VFR DETERIORATING TO MVFR/IFR IN AREAS OF FOG PARTICULARLY ALONG THE SOUTH COAST...CAPE...AND ISLANDS. KBOS TERMINAL...HIGH CONFIDENCE IN TAF. KBDL TERMINAL...HIGH CONFIDENCE IN TAF. OUTLOOK...WEDNESDAY THROUGH SATURDAY...MODERATE CONFIDENCE. BREEZY SW-FLOW WITH 20 KT GUSTS AT TIMES. IFR STRATUS / FOG POSSIBLE ACROSS THE S/SE-COAST. INCREASING CHANCES FOR -SHRA/TSRA BEGINNING LATE WEDNESDAY TO W...MOST EVERYWHERE THURSDAY...CONCLUDING EARLY FRIDAY. TEMPO MVFR-IFR WITH ANY ACTIVITY.
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&& .MARINE...
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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 TUESDAY/...HIGH CONFIDENCE. SMALL CRAFT ADVISORIES ARE UP FOR TONIGHT THROUGH TUESDAY NIGHT...MAINLY ON THE OUTER WATERS FOR INCREASING SEAS AND SOUTHWESTERLY WINDS. WHILE THE WINDS MAY ONLY REACH CRITERIA BRIEFLY...SEAS WILL CLIMB TO 5 FEET AND REMAIN THERE THROUGH THE PERIOD. IN ADDITION...AREAS OF FOG ARE LIKELY TO DEVELOP TUESDAY NIGHT...REDUCING VISIBILITIES. OUTLOOK...WEDNESDAY THROUGH SATURDAY...MODERATE CONFIDENCE. PERSISTENT SW-FETCH WITH GUSTS AROUND 20-25 KTS AT TIMES. STRONGEST WINDS ALONG THE NEAR-SHORE WATERS. WAVE HEIGHTS IN EXCESS OF 5-FEET WITH SWELL AND WIND-WAVE MOSTLY ON THE OUTER WATERS BUT GETTING INTO THE S INNER SOUNDS. DENSE FOG ANTICIPATED LENDING TO VISIBILITY RESTRICTIONS.
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&& .FIRE WEATHER... EXPECT DEWPOINTS TO SLOWLY BUT STEADILY RISE INTO THE 50S TOWARDS THE END OF TODAY. SW WINDS OF 10-20 MPH WITH GUSTS OF 20 TO 25 MPH EXPECTED...UP TO 30 MPH POSSIBLE. FORECASTED MINIMUM RH VALUES WILL BE JUST ABOVE 30-PERCENT ACROSS THE INTERIOR...45 TO 55 PERCENT ON THE SOUTH COAST/CAPE COD/ISLANDS. WITH THE INCREASING HUMIDITY...THERE IS A DECREASED FIRE WEATHER RISK SO WILL NOT BE ISSUING A STATEMENT AT THIS TIME. ALTHOUGH IT WILL BE WARMER ON TUESDAY...DEWPOINTS WILL ALSO BE RISING KEEPING MINIMUM RELATIVE HUMIDITIES FROM 40 TO 50 PERCENT. && .BOX WATCHES/WARNINGS/ADVISORIES...
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CT...NONE. MA...NONE. RI...NONE. MARINE...SMALL CRAFT ADVISORY FROM 2 AM TUESDAY TO 6 AM EDT WEDNESDAY FOR ANZ250-254-255. SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 6 AM EDT WEDNESDAY FOR ANZ235-256.
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&& $$ SYNOPSIS...RLG/SIPPRELL NEAR TERM...RLG SHORT TERM...RLG LONG TERM... AVIATION...RLG/SIPPRELL MARINE...RLG/SIPPRELL FIRE WEATHER...

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