Area Forecast Discussion
Issued by NWS Boston, MA

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000 FXUS61 KBOX 282120 AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 520 PM EDT SUN JUN 28 2015 .SYNOPSIS...
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JUST A FEW SPOT SHOWERS WITH AREAS OF DRIZZLE AND FOG ARE EXPECTED TONIGHT. MAINLY DRY WEATHER RETURNS MONDAY WITH TEMPERATURES SLIGHTLY COOLER THAN NORMAL. WARMER TEMPERATURES MOVE IN TUESDAY AHEAD OF AN APPROACHING COLD FRONT. THIS FRONT WILL BRING SHOWERS/SCATTERED THUNDERSTORMS TUESDAY NIGHT AND WEDNESDAY. SOME STORMS ON WEDNESDAY MAY BE STRONG TO SEVERE ALONG WITH LOCALLY HEAVY RAINFALL. SPOTTY SHOWERS LINGER INTO THURSDAY. DRY AND MILD WEATHER EXPECTED THURSDAY NIGHT INTO FRIDAY BEFORE ANOTHER FRONT APPROACHES BRINGING MORE SCATTERED SHOWERS LATE FRI INTO NEXT WEEKEND.
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&& .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... 350 PM UPDATE... LOW PRESSURE PASSING OVER THE CAPE AND ISLANDS HAS ALLOWED TEMPS TO BRIEFLY CLIMB INTO THE LOWER 70S LATE THIS AFTERNOON IN THAT REGION...WHILE MOST OTHER AREAS WERE IN THE UPPER 50S AND LOWER 60S. TEMPS ACROSS THE CAPE AND ISLANDS WILL DROP SEVERAL DEGREES IN THE NEXT FEW HOURS AS COOLER AIR WORKS BACKS INTO THE REGION BEHIND THE DEPARTING SURFACE LOW. OTHERWISE...JUST A FEW ISOLATED BRIEF SHOWERS ARE POSSIBLE TONIGHT BUT NOTHING WIDESPREAD OR OF LONG DURATION. LOW CLOUDS ALONG WITH AREAS OF FOG AND DRIZZLE WILL BE THE MAIN STORY WITH SHALLOW MOISTURE TRAPPED BENEATH THE INVERSION. DO NOT EXPECT AREAS OF FOG TO BE WIDESPREAD OR DENSE ENOUGH TO WARRANT AN ADVISORY...BUT LATER SHIFTS WILL HAVE TO MONITOR CLOSELY. LOW TEMPS WILL MAINLY BE IN THE 50S WITH SOME LOWER 60S ACROSS PORTIONS OF THE CAPE/ISLANDS. && .SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/... MONDAY... BIGGEST QUESTION MARK FOR MONDAY IS HOW QUICKLY LOW CLOUDS WILL BURN OFF. WE MAY STILL BE DEALING WITH AN ABUNDANCE OF CLOUDS IN THE MORNING...BUT SHOULD SEE SOME PARTIAL SUNSHINE EMERGE DURING THE AFTERNOON. THERE IS A LOW RISK OF A SPOT SHOWER OR TWO ACROSS OUR NORTHWEST ZONES WITH A WEAK SHORTWAVE...BUT PRETTY MUCH A DRY DAY ON TAP. HIGH TEMPS WILL BE IN THE 70S...SO IN A NUTSHELL MUCH BETTER THEN TODAY. BEACH FORECAST... A MODERATE TO EVEN HIGH RISK OF DANGEROUS RIP CURRENTS IS EXPECTED ON SOME OF OUR OCEAN EXPOSED BEACHES ON MONDAY. HIGH SURF ADVISORIES ARE IN EFFECT UNTIL 8 PM THIS EVENING...BUT THE NEXT SHIFT MAY HAVE TO CONSIDER A RIP CURRENT STATEMENT FOR MONDAY. && .LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
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HIGHLIGHTS... * SHOWERS AND SCATTERED THUNDERSTORMS POSSIBLE TUESDAY NIGHT AND WEDNESDAY...THEN SPOTTY SHOWERS LINGER INTO THURSDAY * SOME STORMS MAY BE STRONG WEDNESDAY WITH LOCALLY HEAVY RAINFALL * DRY AND MILD THU NIGHT INTO FRIDAY * ANOTHER FRONT APPROACHES LATE FRIDAY INTO NEXT WEEKEND WITH MORE SCT SHOWERS SYNOPTIC OVERVIEW AND MODEL PREFERENCES... 12Z OP MODEL SOLUTIONS IN GOOD AGREEMENT INTO WED NIGHT...THEN SOLUTIONS WIDEN IN THE RESPONSE TO THE POSSIBLE BREAKING DOWN OF THE LONG WAVE AMPLIFIED UPPER LEVEL RIDGE/TROUGH ACROSS NORTH AMERICA LATE THIS WEEK INTO THE HOLIDAY WEEKEND. IT APPEARS THAT THE TROUGHING BECOMES LESS AMPLIFIED OVER TIME ACROSS THE NORTHEAST... WHICH PRESENTS PROBLEMS IN TRYING TO TIME SENSIBLE WEATHER SURFACE SYSTEMS IN THIS FAST FLOW ALOFT. UNCERTAINTY INCREASES FROM THURSDAY INTO THE WEEKEND WITH ANY APPROACHING SYSTEM...ESPECIALLY AS THE NORTHERN STREAM REMAINS ACTIVE. DOES LOOK LIKE THERE WILL BE SOME BREAKS IN THE ACTION BETWEEN EACH SYSTEM SO THERE WILL BE SOME DRY PERIODS AS WELL. 12Z OP MODEL SUITE CONTINUE TO SIGNAL A RATHER STRONG SYSTEM DURING THE TUE NIGHT/WED TIMEFRAME WHICH CONTINUES TO HAVE VERY GOOD MODEL SUPPORT AND AGREEMENT. PLAN ON USING BLEND OF AVAILABLE MODEL GUIDANCE THROUGH WED NIGHT THEN WILL TRANSITION OVER TO ENSEMBLES /GEFS AND ECENS/ FOR THE REMAINDER OF THE FORECAST DUE TO THE LARGE TIMING AND TRACK DIFFERENCES AMONGST THE OPERATIONAL MODEL RUNS. DETAILS... MONDAY NIGHT...WEAK SURFACE RIDGING PUSHES QUICKLY ACROSS THE REGION...SO EXPECT DRY BUT COOL CONDITIONS UNDER MOSTLY CLEAR SKIES. CLOUDS MAY START TO INCREASE TOWARD DAYBREAK ACROSS WESTERN AREAS. LOWS WILL BE MAINLY IN THE 50S...RANGING TO THE LOWER 60S ALONG THE IMMEDIATE COAST. TUESDAY...NEXT SURFACE LOW AND FRONT SLOWLY APPROACH FROM THE W IN THE NEARLY PARALLEL UPPER LEVEL SW WIND FLOW. WILL SEE INCREASING CLOUDS DURING THE DAY BUT...DUE TO SLOW MOVEMENT...LOOKS LIKE BULK OF THE PRECIP REMAINS W OF THE REGION. MAY SEE A FEW SHOWERS WORK INTO THE E SLOPES OF THE BERKSHIRES. GOOD WARM AIR ADVECTION WORKING IN THE SW FLOW SO EXPECT HIGHS MAINLY AROUND 80...JUST ABOUT AT THE SEASONAL NORM FOR LATE JUNE. TUESDAY NIGHT-WEDNESDAY...AS THE H5 SHORT WAVE AND SURFACE FRONT SLOWLY APPROACH TUE NIGHT...WILL START TO SEE SCT SHOWERS MOVE IN EARLY. BETTER DYNAMICS AND SCT ELEVATED CONVECTION LOOK TO APPROACH AROUND OR AFTER MIDNIGHT ACROSS WESTERN AREAS THEN SHIFTS E TOWARD DAYBREAK WED. BEST SHOT FOR PRECIP LOOKS TO OCCUR DURING WED...AND HAVE MENTIONED SPOTTY CATEGORICAL POPS INLAND. WITH THE SW UPPER FLOW IN PLACE... THIS SYSTEM REMAINS A SLOW MOVER. DEWPTS FORECAST TO RISE TO THE MID AND UPPER 60S ALONG WITH PWATS INCREASING WITH THE SW FLOW...ON ORDER OF 1.7 TO 1.9 INCHES. WILL LIKELY SEE SOME HEAVY RAINFALL ESPECIALLY IN ANY THUNDERSTORMS. IMPRESSIVE INSTABILITY WITH THIS SYSTEM...K INDICES TO THE UPPER 30S AND CAPES INCREASING TO 1000- 1500 J/KG WED AFTERNOON ALONG WITH GOOD SW SHEAR /H925 WINDS AROUND 30 KT AND H85 WINDS 30-35 KT/ ALONG WITH A STRONG UPPER JET PASSING ACROSS. H5 COLD POOL ALSO SNEAKS IN...WITH TEMPS DOWN TO -10C TO -12C WED AFTERNOON. SO...WILL BE MONITORING THIS SYSTEM CLOSELY FOR THE POSSIBILITY OF STRONG TO SEVERE STORMS. WEDNESDAY NIGHT-THURSDAY...COLD FRONT WILL SLOWLY PUSH TOWARD THE S COAST WED NIGHT THEN LOOKS TO STALL A BIT FURTHER DOWN THE COAST. WILL STILL SEE LEFTOVER SHOWERS/ISOLD TSTMS BUT SHOULD PUSH OFFSHORE BY MIDNIGHT. PATCHY FOG WILL ALSO DEVELOP MAINLY AFTER MIDNIGHT. THEN...ON THURSDAY...SKIES WILL START OFF PARTLY TO MOSTLY SUNNY. HOWEVER...WITH THE H5 COLD POOL ALOFT WILL SEE SOME SCT DIURNAL SHOWERS DEVELOP MAINLY INLAND. ONLY CARRIED 20-30 PCT CHANCE MAINLY FROM LATE MORNING THROUGH THE AFTERNOON. THE SHOWERS SHOULD END WITH SUNSET. FRIDAY THROUGH SUNDAY...A LOT OF UNCERTAINTY DUE TO WIDE MODEL SOLUTIONS. AT THIS POINT...SHOULD BE A DRY DAY FOR MOST OF FRIDAY BEFORE MORE SCT SHOWERS MOVE IN. LOTS OF QUESTIONS ABOUT WHETHER A WAVE OF LOW PRES FORMS ON STALLED FRONT TO THE S THAT MAY BRING MORE MOISTURE FOR LATE FRIDAY INTO SATURDAY MORNING. CARRIED ONLY CHANCE POPS FOR THIS. TIMING IS VERY MUCH IN QUESTION FOR YET ANOTHER FAST MOVING SYSTEM LATE THIS WEEKEND. TEMPS OVER THE 4TH OF JULY WEEKEND LOOK TO BE CLOSE TO OR ONLY SLIGHTLY BELOW SEASONAL NORMS.
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&& .AVIATION /21Z SUNDAY THROUGH FRIDAY/...
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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 MONDAY/... TONIGHT...MODERATE TO HIGH CONFIDENCE. MAINLY IFR TO EVEN LOCALIZED LIFR CONDITIONS WILL PERSIST THROUGH TONIGHT IN LOW CLOUDS...AREAS OF FOG/DRIZZLE ALONG WITH PASSING SHOWER OR TWO. MOISTURE WILL JUST REMAINED TRAPPED BELOW THE INVERSION. MONDAY...MODERATE TO HIGH CONFIDENCE IN TRENDS BUT TIMING IS UNCERTAIN. AREAS OF LOW CLOUDS AND FOG PATCHES IN THE MORNING SHOULD IMPROVE TO VFR BUT IT MAY TAKE UNTIL AFTERNOON FOR THIS TO HAPPEN IN SOME LOCATIONS. THIS AS DRIER AIR WORKS IN FROM THE WEST. KBOS TERMINAL...MODERATE TO HIGH CONFIDENCE IN TAF...BUT UNCERTAIN AS TO EXACTLY WHEN CONDITIONS IMPROVE TO MVFR AND THEN VFR ON MONDAY. KBDL TERMINAL...MODERATE TO HIGH CONFIDENCE IN TAF...BUT UNCERTAIN AS TO EXACTLY WHEN CONDITIONS IMPROVE TO MVFR AND THEN VFR ON MONDAY OUTLOOK...MONDAY NIGHT THROUGH FRIDAY...MODERATE CONFIDENCE. MONDAY NIGHT...MAINLY VFR. PATCHY FOG AFTER MIDNIGHT WITH LOCAL MVFR-IFR CONDITIONS. TUESDAY...VFR MOST AREAS. PATCHY FOG EARLY TUE WITH LOCAL MVFR CONDITIONS IMPROVING BY AROUND 14Z. LOW CHANCE OF MVFR CONDITIONS ACROSS N CT INTO WESTERN-CENTRAL MA IN SCATTERED AFTERNOON SHOWERS/THUNDERSTORMS. TUESDAY NIGHT AND WEDNESDAY...HIGHEST RISK FOR SHOWERS AND T-STORMS. A FEW STRONG STORMS POSSIBLE WED WITH GUSTY WINDS. MVFR LIKELY. LOCAL IFR IN ANY PATCHY FOG LATE TUE NIGHT INTO WED MORNING. WEDNESDAY NIGHT AND THURSDAY...LEFTOVER MVFR CONDITIONS IN ANY SHOWERS/TSTMS EARLY WED NIGHT...THEN TRENDING TOWARD VFR WITH SHOWERS ENDING. LOW CHANCE FOR SPOTTY SHOWERS LATE THU MORNING THROUGH THE AFTERNOON INLAND...BRIEF LOCAL MVFR.
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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 /TONIGHT AND MONDAY/... TONIGHT AND MONDAY...MODERATE TO HIGH CONFIDENCE. ALL GALE WARNINGS HAVE BEEN CONVERTED TO SMALL CRAFT HEADLINES AS WINDS HAVE DIMINISHED SOME BY LATE THIS AFTERNOON. IN FACT...HEADLINES WERE COMPLETELY DROPPED IN CAPE COD BAY AND SOME EASTERN BAYS/SOUNDS AS WINDS HAVE DIMINISHED WITH SURFACE LOW PRESSURE NEARBY. OTHERWISE...SMALL CRAFT HEADLINES FOR SEAS WILL CONTINUE FROM LEFT OVER SWELL THROUGH MONDAY ACROSS THE WESTERN SOUNDS AND ALL OUTER- WATERS. AREAS OF FOG WILL REDUCE VISIBILITY AT TIMES FOR MARINERS INTO MONDAY MORNING. FINALLY...MAY ALSO SEE A PERIOD OF SOUTHWEST WIND GUSTS NEAR 25 KNOTS ACROSS BUZZARDS BAY/NANTUCKET SOUND AND CAPE COD BAY MONDAY AFTERNOON. IF CONFIDENCE ON THE NEXT SHIFT GROWS...THEY MAY NEEDED TO BE ADDED TO THE SMALL CRAFT HEADLINES FOR A TIME. OUTLOOK...MONDAY NIGHT THROUGH FRIDAY...MODERATE CONFIDENCE. MONDAY NIGHT...LEFTOVER SW GUSTS TO 25 KT ON THE SOUTHERN OUTER WATERS WILL END EARLY. SEAS WILL REMAIN AT 5-7 FT EARLY ON THE SOUTHERN OUTER WATERS BUT SHOULD SUBSIDE AROUND OR AFTER MIDNIGHT. DRY WEATHER AND GOOD VSBY. TUESDAY...EXPECT LIGHT S WINDS AND SEAS 4 FT OR LESS. TUESDAY NIGHT AND WEDNESDAY...EXPECT S-SW WINDS TO INCREASE AHEAD OF APPROACHING COLD FRONT. GUSTS TO 20 KT MAINLY ON THE OUTER WATERS. SEAS BUILDING UP TO 5-6 FT MAINLY ON THE SOUTHERN WATERS. SHOWERS AND SCATTERED THUNDERSTORMS DEVELOPING ALONG WITH PATCHY FOG. THURSDAY...WINDS SHIFT TO W AND DIMINISH. SEAS REMAIN AROUND 5 FT ON THE OUTER WATERS. FRIDAY...LIGHT WINDS BECOME E-SE. MAY SEE WIDELY SCT SHOWERS. PATCHY FOG REDUCING VSBYS.
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&& .BOX WATCHES/WARNINGS/ADVISORIES...
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CT...NONE. MA...HIGH SURF ADVISORY UNTIL 8 PM EDT THIS EVENING FOR MAZ007-015- 016-019>024. RI...HIGH SURF ADVISORY UNTIL 8 PM EDT THIS EVENING FOR RIZ006>008. MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ230. SMALL CRAFT ADVISORY UNTIL 1 AM EDT TUESDAY FOR ANZ235-237. SMALL CRAFT ADVISORY UNTIL 11 AM EDT MONDAY FOR ANZ250-251. SMALL CRAFT ADVISORY UNTIL 6 AM EDT TUESDAY FOR ANZ254>256.
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&& $$ SYNOPSIS...FRANK/EVT NEAR TERM...FRANK SHORT TERM...FRANK LONG TERM...EVT AVIATION...FRANK/EVT MARINE...FRANK/EVT

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