Area Forecast Discussion
Issued by NWS Boston, MA

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000 FXUS61 KBOX 302320 AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 720 PM EDT THU JUL 30 2015 .SYNOPSIS...
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WET-WEATHER THIS EVENING EXITING OFF THE COAST WILL GIVE WAY TO DRIER WEATHER FRIDAY...BUT IT WILL REMAIN VERY WARM. WARM AND HUMID CONDITIONS WILL RETURN THIS WEEKEND...THEN WILL BECOME LESS HUMID WITH TEMPERATURES CLOSER TO NORMAL NEXT WEEK. THERE IS A LOW RISK FOR SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS THIS WEEKEND INTO EARLY NEXT WEEK...HOWEVER MUCH OF THE TIME DRY WEATHER WILL PREVAIL.
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&& .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
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730 PM UPDATE... FRONTAL BOUNDARY PUSHING SE INTO NW MASSACHUSETTS AHEAD OF WHICH WIDESPREAD RAIN AND ISOLATED THUNDERSTORMS WILL CONTINUE AHEAD OF WHICH HIGH DEWPOINT AIR PREVAILS. SOME ACTIVITY AHEAD OF THE FRONT BUT FEEL THAT THE ENVIRONMENT IS GASSED BY EARLIER WEATHER. SOME INSTABILITY AND SHEAR TO WORK WITH BUT THINK THE MAIN CONCERNS OVER THE NEXT 6-12 HOURS AS WET- WEATHER PUSHES OFFSHORE AHEAD OF THE FRONT WILL BE THE THREAT OF HEAVY RAINFALL AND LOCALIZED FLOODING...BUT THIS LOOKS LIKE A LOW RISK AT THIS POINT...ALONG WITH PATCHY DENSE FOG AND LOW CLOUDS WHICH APPEARS TO BE MORE OF A HIGH RISK FOR SE MASSACHUSETTS WHERE DEWPOINTS RANGE IN THE MID-70S AND WET-WEATHER IS JUST ENCROACHING ON THE REGION. OTHERWISE...BLUSTERY S/SW-WINDS AHEAD OF THE FRONT WITH GUSTS AROUND 15 TO 25 MPH...ESPECIALLY OVER THE CAPE/ISLANDS WHERE A H925 JET-MAX RESIDES. WINDS SHOULD DROP OFF DURING THE EVENING WITH THE APPROACH AND PASSAGE OF THE FRONT...WITH WINDS BACKING W/NW REARWARD AND DEWPOINTS DROPPING TO MORE COMFORTABLE LEVELS. MUGGY NIGHT FOR THOSE IN SE NEW ENGLAND...REFRESHING FOR THOSE IN CENTRAL- AND NW-PORTIONS OF S NEW ENGLAND. LOWS AROUND THE 60S.
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&& .SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
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FRONT WILL BE OFFSHORE FRIDAY MORNING WITH DRIER AND MORE COMFORTABLE AIRMASS IN ITS WAKE. KEEPING FRIDAY NIGHT DRY ALTHOUGH WE SHOULD SEE INCREASING CLOUDS AS NEXT SHORT WAVE APPROACHES.
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&& .LONG TERM /SATURDAY THROUGH THURSDAY/... HIGHLIGHTS... * EXPECT MORE SEASONABLE TEMPS AND LOWER HUMIDITY THROUGH MOST OF THIS PERIOD * CHANCE FOR A FEW SHOWERS/ISOLATED THUNDER EACH DAY BUT MUCH OF THE TIME REMAINING DRY SYNOPTIC OVERVIEW AND MODEL PREFERENCES... MEDIUM RANGE FORECAST CONTINUES TO FEATURE ANOMALOUS H5 CUTOFF VORTEX ACROSS JAMES AND HUDSON BAYS WHICH WILL ELONGATE ACROSS QUEBEC DURING THE LONG TERM PERIOD. WILL STILL SEE LONG WAVE TROUGH ACROSS THE EASTERN GREAT LAKES AND DOWN THE APPALACHIANS WHICH WILL TEND TO FLATTEN...THOUGH SHORT WAVES WILL ROTATE AROUND THE BASE OF THE CUTOFF LOW INTO THE MEAN TROUGH. THIS WILL BRING PERIODS OF SHOWERS/THUNDERSTORMS ACROSS THE REGION FROM TIME TO TIME. NOT EXPECTED A TOTAL WASHOUT AT ANY TIME...THOUGH MODELS LOOK LIKE THEY MAY HAVE SOME CONTINUITY WILL BE AROUND THE LATE MON/MON NIGHT AND TUE NIGHT TIMEFRAMES. HOWEVER...OPERATIONAL MODEL SOLUTION SPREAD DOES WIDENS OVER TIME AS ONE WOULD EXPECT ESPECIALLY THIS TIME OF THE YEAR...SO CONFIDENCE IN SPECIFIC TIMING OF CONVECTION AND ANY SHORT WAVE PASSAGE LOWERS. USED A BLEND OF AVAILABLE GUIDANCE INTO MONDAY...THEN TRANSITIONED OVER TO THE GFS AND EC ENS MEANS WHICH GAVE A BIT MORE CONTINUITY WITH PREVIOUS FORECASTS. DETAILS... SATURDAY...MODELS CONTINUE TO PAINT A WEAK H5 SHORT WAVE IN THE MEAN UPPER FLOW FOR LATER SAT INTO SAT NIGHT. LOOKS LIKE BEST INSTABILITY AND MOISTURE...WHAT THERE IS OF IT...WILL BE ACROSS CENTRAL AND WESTERN AREAS. ANOTHER QUESTION WILL BE WHETHER THERE WILL BE SOME NOCTURNAL INSTABILITY SHOWERS/TSTMS ALONG THE S COAST WHERE HIGHEST HUMIDITIES ARE IN PLACE. HAVE LEFT OUT FOR NOW...BUT IT IS SIGNALED ON THE GFS MODEL. HAVE GENERALLY SLIGHT CHANCE POPS GOING...BUT MAY SEE A LINE OF SCT SHOWERS/TSTMS ACROSS CT VALLEY INTO CENTRAL MA/NE CT POSSIBLE DURING THE LATE AFTERNOON/EARLY EVENING. EXPECT THE SHORT WAVE TO SHIFT E AND WEAKEN SO PRECIP SHOULD ALSO WEAKEN OVERNIGHT. HIGHS WILL GENERALLY BE IN THE 80S. IT WILL BE COOLER WELL INLAND LATE SAT NIGHT WITH LOWS AROUND 60...RANGING TO AROUND 70 ALONG THE S COAST...CAPE COD AND THE ISLANDS. SUNDAY...WEAK SURFACE RIDGE BUILDS ACROSS SO EXPECT A MAINLY DRY DAY. H85 TEMPS WILL BE FROM +15C TO +16C...WHICH WILL TRANSLATE TO THE 80S FOR MOST AREAS...A BIT COOLER ALONG THE S COAST WITH THE S- SW WINDS IN PLACE. MONDAY...SOUTHWEST WIND FLOW REMAINS IN PLACE. MODELS SIGNALING A POSSIBLE PRE FRONTAL TROUGH APPROACHING LATE MON OR MON NIGHT /TIMING IN QUESTION/. MAY SEE WIDELY SCT SHOWERS/ISOLD TSTMS ACROSS CENTRAL AND WESTERN AREAS...WITH THE BEST CHANCE ACROSS W MA AND W HARTFORD COUNTY. WITH THE MILDER S-SW FLOW IN PLACE...EXPECT HIGHS MAINLY IN THE 80S. TUESDAY...W-SW FLOW ALOFT AS QUEBEC VORTEX BROADENS. ANOTHER SHORT WAVE AND ASSOCIATED COLD FRONT LOOKS TO APPROACH LATE TUE INTO TUE EVENING. GFS MOST AGGRESSIVE IN DIGGING H5 TROUGH TO THE W WHICH WILL KEEP WARM AND HUMID AIR IN PLACE. HAVE CARRIED CHANCE POPS ACROSS THE REGION...THEN SHOULD PUSH OFFSHORE TUE NIGHT. WEDNESDAY-THURSDAY...A LOT OF QUESTIONS AS TO WHETHER FRONT WILL STALL S OF NEW ENGLAND DURING THIS TIMEFRAME AND IF WAVES WILL MOVE ALONG THIS FRONT. FOR NOW...HAVE CHANCE POPS MOVING ACROSS WED NIGHT/THU...BUT TIMING IS STILL VERY MUCH IN QUESTION. LOW CONFIDENCE DURING THIS TIMEFRAME DUE TO TIMING DIFFERENCES. && .AVIATION /00Z FRIDAY THROUGH TUESDAY/...
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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 FRIDAY NIGHT/...HIGH CONFIDENCE. WIDESPREAD -RA WITH ISOLATED -TSRA CONTINUES AHEAD OF A FRONT THRU FRIDAY MORNING...CONCLUDING NW-SE WITH SW-FLOW /BREEZY OVER THE CAPE AND ISLANDS AT 15-25 KTS/ BACKING W/NW REARWARD. MAINLY LOW- END VFR...BUT LIKELY IFR-LIFR TO BECOME AN ISSUE FOR FAR SE NEW ENGLAND TERMINALS WITH LOW CIGS AND FOG. MVFR VSBYS WITH ANY +RA/TSRA. LOW RISK OF STRONGER WIND GUSTS. FRIDAY AND FRIDAY NIGHT... VFR. W/SW-WINDS. SEA-BREEZES POSSIBLE ALONG THE COASTS. KBOS TERMINAL...HIGH CONFIDENCE IN TAF. RAIN CHANCES CONTINUE THRU ROUGHLY 6Z. KBDL TERMINAL...HIGH CONFIDENCE IN TAF. RAIN CHANCES CONTINUE THRU ROUGHLY 4Z. OUTLOOK /SATURDAY THROUGH TUESDAY/...MODERATE CONFIDENCE. EXPECT GENERALLY VFR MOST OF THE TIME. LOW CHANCE OF SCT SHOWERS/ ISOLD THUNDERSTORMS SAT AFTERNOON/EARLY SAT NIGHT AND AGAIN MON-TUE. BRIEF LOCAL MVFR IN ANY PRECIP.
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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 FRIDAY NIGHT/...HIGH CONFIDENCE. SCA REMAINS POSTED FOR 20-30 KT GUSTS THIS AFTERNOON NEAR SHORE AS GRADIENT TIGHTENS AHEAD OF COLD FRONT. IN ADDITION...LONG SOUTHWEST FETCH WILL ALLOW FOR SEAS TO BUILD TO BETWEEN 3 TO 5 FEET ACROSS MOST OPEN WATERS. WINDS DIMINISH THIS EVENING...BUT KEEPING SCA THROUGH TONIGHT FOR THE OUTER WATERS DUE TO LEFTOVER SWELL. HIGH PRESSURE WILL BUILD OVER REGION FRI AND FRI NIGHT WITH LIGHT WINDS AND DIMINISHING SEAS. OUTLOOK /SATURDAY THROUGH TUESDAY/... SATURDAY-SUNDAY...SW WINDS MAY GUST UP TO 20 KT SAT/SAT NIGHT THEN DIMINISH. WITH LONG S-SW FETCH...SEAS FORECAST UP TO 5 FT MAINLY ON THE SOUTHERN OUTER WATERS. MONDAY-TUESDAY...CONTINUED SW WINDS IN PLACE...WHICH MAY GUST TO 20 KT AT TIMES. SEAS UP TO 5-7 FT ON THE SOUTHERN OUTER WATERS. MAY SEE SCT SHOWERS/THUNDERSTORMS MON NIGHT/TUE.
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&& .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. RI...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR ANZ230>234-236-251. SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR ANZ235- 237. SMALL CRAFT ADVISORY UNTIL 8 AM EDT FRIDAY FOR ANZ250-254>256. && $$ SYNOPSIS...EVT/JWD NEAR TERM...SIPPRELL/JWD SHORT TERM...JWD LONG TERM...EVT AVIATION...EVT/JWD MARINE...EVT/JWD

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