Area Forecast Discussion
Issued by NWS Boston, MA

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000 FXUS61 KBOX 290755 AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 355 AM EDT FRI MAY 29 2015 .SYNOPSIS...
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HIGH PRESSURE WILL BRING DRY CONDITIONS TODAY. ANOTHER COLD FRONT WILL SLOWLY MOVE ACROSS THE REGION THIS WEEKEND...BRINGING A GREATER CHANCE FOR SHOWERS AND SOME SCATTERED THUNDERSTORMS. THIS FRONT MAY LINGER NEAR OUR AREA INTO THE BEGINNING OF THE NEXT WEEK...WITH HIGH PRESSURE RETURNING BY MIDWEEK.
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&& .NEAR TERM /UNTIL 6 PM THIS EVENING/...
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4 AM UPDATE... COLD FRONT CONTINUES TO SLOWLY PUSH ACROSS THE SOUTH COAST THIS MORNING. IT HAS PUSHED THROUGH BLOCK ISLAND...BUT IS TILL HUNG UP ACROSS THE CANAL TOWARDS PROVINCETOWN. THIS FRONT EVENTUALLY WILL WASHOUT THIS MORNING. AHEAD OF THE FRONT...DEWPOINTS CONTINUE TO POOL ALONG IT ALLOWING FOR LOW-LEVEL MOISTURE TO INCREASE. WITH DRY AIR MOVING IN ALOFT PER CLEAR SKIES...A LOW LEVEL INVERSION HAS SET UP ALLOWING FOR FOG. VSBYS HAVE DROPPED DOWN TO 1SM ACROSS PORTIONS OF SOUTHEAST MASS/CAPE/ISLANDS. IN FACT FMH IS DOWN TO 1/4SM. AS THE SUN BEGINS TO RISE...EXPECT FOG TO DISSIPATE ONCE MIXING WILL OCCUR. TODAY... HIGH PRESSURE WILL MOVE OVERHEAD YIELDING TO DRY WEATHER FOR THE DAY. SOME MID-LEVEL MOISTURE WILL POOL IN FROM THE NORTH AND WITH STEEPENING LAPSE RATES FROM DIURNAL HEATING...WILL SEE DIURNAL CLOUDS DEVELOP. OTHERWISE WEAK WINDS ALOFT WILL ALLOW FOR SEA BREEZES TO EVOLVE AND MOVE ALONG THE COASTLINES. TEMPS WILL STILL BE ABOVE AVERAGE...WITH HIGHS REACHING INTO THE LOW TO MID 80S WITH 70S ALONG THE COASTLINES.
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&& .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/...
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TONIGHT... HIGH PRESSURE WILL BEGIN TO SHIFT OFFSHORE AS SOUTHWESTERLY FLOW RETURNS TO THE REGION. THIS WILL ALLOW FOR ANOTHER MILD AND MUGGY NIGHT FOR SOUTHERN NEW ENGLAND. WAA WILL BE ON THE INCREASE WHICH WILL INCREASE CLOUD COVER...ESP FOR THE SOUTH COASTAL REGIONS. CANNOT RULE OUT ANOTHER ROUND OF MARINE FOG/STRATUS. OTHERWISE TEMPS WILL REMAIN IN THE UPPER 50S TO LOW 60S WITH DEWPOINTS ALSO IN THE MID TO UPPER 50S. TOMORROW... COLD FRONT WILL MOVE ACROSS THE GREAT LAKES REGION ON SATURDAY ALLOW FOR SHOWERS AND THUNDERSTORMS TO DEVELOP. BEST DYNAMICS AND FORCING WILL BE WELL TO THE WEST OF THE REGION...HOWEVER BECAUSE WE ARE IN A VERY WARM AND MOIST AIRMASS CANNOT RULE OUT A FEW POP-UP SHOWERS AND THUNDERSTORMS OUT AHEAD OF THIS FRONT LATE SATURDAY AFTERNOON/EVENING. OTHERWISE BULK OF THE DAY WILL BE DRY WITH TEMPS WARMING INTO THE LOW TO MID 80S...COOLER ALONG THE SOUTH COAST.
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&& .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... OVERVIEW AND MODEL PREFERENCES... OVERALL UPPER LEVEL RIDGING ALONG EASTERN SEABOARD APPEARS TO BREAK DOWN SATURDAY...THEN TROUGH OUT OF CENTRAL CANADA BEGINS TO SHIFT E LATE THIS WEEKEND INTO EARLY NEXT WEEK. ASSOCIATED COLD FRONT WILL BE SLOW TO CLEAR THE REGION AS IT RUNS PARALLEL TO THE UPPER FLOW. TIMING ISSUES COME IN PLAY FROM MONDAY ONWARD... DEPENDING UPON HOW FAR S THE FRONT FINALLY SETTLES WHILE HIGH PRES BUILDS OUT OF SOUTHERN ONTARIO AND THE GREAT LAKES EASTWARD. LEANED TOWARD THE AVAILABLE GUIDANCE EARLY IN THIS PERIOD THEN TRANSITIONED OVER THE GEFS AND ECENS GUIDANCE WHICH SHOWED A BIT BETTER CONTINUITY. DETAILS... SATURDAY...HIGH PRES OFF THE EASTERN SEABOARD PUSHES FURTHER OFFSHORE DURING THIS TIMEFRAME...WITH GOOD SW WIND FLOW AND INCREASING HUMIDITY MOVING NE INTO THE REGION. MODELS TENDING TO SLOW THE PROGRESS OF THE APPROACHING FRONT OUT OF WESTERN QUEBEC AS THE UPPER RIDGE SLOWLY BREAKS DOWN AND SHIFTS E. HAVE MENTION OF CHANCE POPS MOVING INTO WESTERN AREAS DURING SAT AFTERNOON... THEN SHOULD PUSH SLOWLY SE SAT NIGHT. GOOD INSTABILITY WITH THIS FRONT AS K INDICES INCREASE TO THE LOWER-MID 30S. HAVE MENTIONED CHANCE POPS...BUT MENTIONED ONLY SLIGHT CHANCE OF THUNDERSTORMS SAT NIGHT. NOTING INCREASING PWATS ALONG AND AHEAD OF THIS FRONT AS WELL...UP TO 1.7 INCHES DURING SAT NIGHT SO COULD SEE SOME LOCALLY HEAVY DOWNPOURS WITH ANY ACTIVITY. WILL SEE HIGH TEMPS REACH AROUND 80 INLAND...BUT ONLY IN THE UPPER 60S TO LOWER 70S ALONG THE IMMEDIATE S COAST. MAY SEE SW WINDS GUSTING UP TO AROUND 25-30 MPH ACROSS RI/SE MA SAT AFTERNOON/NIGHT. SUNDAY...LOOKS LIKE BEST SHOT OF MOISTURE MOVES ACROSS THE REGION SUN/SUN NIGHT. CARRYING CAT POPS NEAR/ALONG THE SLOWLY MOVING FRONT...AS WELL AS SOME SCT THUNDERSTORMS. PWATS INCREASE TO 1.7 TO 1.8 INCHES...SO COULD ALSO SEE SOME HEAVY DOWNPOURS. AT THIS POINT...THINK THE FRONT WILL PUSH NEAR OR S OF THE MASS PIKE AROUND SUN NIGHT...BUT WILL TEND TO SLOW DOWN ACROSS SOUTHERN AREAS OVERNIGHT. THIS WILL LOWER THE CHANCE FOR THUNDERSTORMS AS MORE STABLE AIR MOVES INTO N MA SUN NIGHT...BUT STILL COULD SEE SPOTTY CONVECTION ACROSS N CT/RI/SE MA. HAVE KEPT LIKELY POPS GOING THROUGH AROUND 06Z...THEN SLOWLY LOWER ACROSS CENTRAL AND NORTHERN AREAS AFTER THAT. PRECIP LOOKS TO TAPER OFF ACROSS THE ROUTE 2 AREA BY AROUND SUNRISE MON...BUT TIMING IS STILL IN QUESTION. MONDAY...A LOT OF UNCERTAINTY CONTINUES AS MOVING THE FRONT ACROSS THE REGION...WITH TIMING DIFFERENCES AMONGST THE MODEL SUITE. LOOKS LIKE THE CHANCE FOR PRECIP LINGERS THROUGH MON AND EVEN INTO MON NIGHT...WITH THE BEST CHANCE ACROSS N CT/RI/SE MA. WINDS DO START TO SHIFT AROUND TO N-NE ACROSS CENTRAL AND N MA SO THIS WILL CUT BACK ON THUNDERSTORM ACTIVITY AS COOLER AIR MOVES IN. FOR NOW...TEND TO TAPER OFF PRECIP BY MON NIGHT ACROSS MOST AREAS...BUT DO LINGER IT ALONG THE S COAST THROUGH AT LEAST MIDNIGHT MON NIGHT. IT WILL BE MUCH COOLER WITH HIGHS ONLY IN THE 60S...AND MAY NOT EVEN BREAK 60 ALONG THE E COAST WITH ONSHORE WINDS. TUESDAY-WEDNESDAY...PRECIP SHOULD FINALLY PUSH OFF THE S COAST BY AROUND MIDDAY TUE AT THE LATEST. NE WINDS PICK UP AS HIGH PRES CROSSES NORTHERN NEW ENGLAND DURING THIS TIMEFRAME. HAVE CARRIED A DRY AND SEASONABLE FORECAST ON WEDNESDAY. && .AVIATION /08Z FRIDAY THROUGH TUESDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. BEFORE 12Z...HIGH CONFIDENCE. COLD FRONT WILL SWEEP THROUGH OVERNIGHT. AHEAD OF FRONT COULD SEE IFR/MVFR STRATUS AND FOG. ALSO COULD SEE MVFR FOG DEVELOP ACROSS CT VALLEY SITES. TODAY AND TONIGHT...HIGH CONFIDENCE. MAINLY VFR. EXPECT SEA BREEZES WITH WINDS SHIFTING MAINLY TO THE E LATE IN THE DAY. SOME PATCHY MVFR CIGS COULD DEVELOP ALONG SOUTH COAST TONIGHT. SATURDAY...MODERATE CONFIDENCE. MAINLY VFR THROUGH THE DAY. MVFR CIGS COULD DEVELOP WITHIN -SHRA/-TSRA ACROSS CT VALLEY REGION. KBOS TERMINAL...HIGH CONFIDENCE IN TAF. SEA BREEZE WILL DEVELOP BETWEEN 13-15Z. KBDL TERMINAL...HIGH CONFIDENCE IN TAF. OUTLOOK...SUNDAY THROUGH TUESDAY...MODERATE CONFIDENCE. SUNDAY...NUMEROUS SHOWERS WITH SCATTERED TSTMS POSSIBLE DURING THE DAY WITH LOCAL MVFR CONDITIONS. LIGHT WINDS SHIFT TO N-NE DURING THE DAY...THEN BECOME NE SUN NIGHT WHICH MAY GUST UP TO AROUND 20 KT ALONG THE S COAST. SHOWERS LINGER SUNDAY NIGHT. MONDAY...SCT SHOWERS LINGERING WITH LOCAL MVFR CONDITIONS EARLY BUT WILL IMPROVE FROM N-S DURING THE DAY EXCEPT ALONG THE S COAST WHERE SHOWERS WILL HANG IN THROUGH SUN NIGHT. MAY SEE BRIEF MVFR IN ANY SHOWERS THERE SUN NIGHT. NE WINDS GUSTING TO 20-25 ACROSS OUTER CAPE COD AND THE ISLANDS. TUESDAY...MAINLY VFR CONDITIONS. MAY SEE ISOLD SHOWERS EARLY TUE ALONG S COAST BUT SHOULD MOVE OFFSHORE. NE WIND GUSTS TO 25 KT STILL POSSIBLE ACROSS THE OUTER CAPE AND ISLANDS. && .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 THROUGH FRIDAY NIGHT/... TODAY AND TONIGHT...HIGH CONFIDENCE. HIGH PRES BUILDS OVER THE WATERS. MAINLY QUIET BOATING WEATHER EXPECTED ALTHOUGH SOME STRATUS/FOG IS POSSIBLE MAINLY ON THE SRN WATERS TONIGHT. SATURDAY...HIGH CONFIDENCE. HIGH PRESSURE WILL PUSH EAST OF THE WATERS AS COLD FRONT APPROACHES NEW ENGLAND. SW WINDS MAY GUST NEAR 25-30 KTS. MAY NEED NEAR SHORE SCA. OTHERWISE SEAS WILL BE CLOSE TO 5FT AS SOUTHERLY SWELL INCREASES. OUTLOOK...SUNDAY THROUGH TUESDAY...MODERATE CONFIDENCE. SUNDAY...COLD FRONT SLOWLY CROSSES THE WATERS. MAY SEE BRIEF GUSTS TO 25 KT AS FRONT PASSES DURING SUNDAY...THEN WILL STALL NEAR OR JUST S OF THE S COAST SUN NIGHT. WINDS SHIFT TO E-NE AS FRONT PASSES. AREAS OF SHOWERS WITH SCT THUNDERSTORMS. LOCAL VSBY RESTRICTIONS. MONDAY-TUESDAY...EXPECT MAINLY NE WINDS. GUSTS TO 25 KT ACROSS THE SOUTHERN OPEN WATERS AS THE FRONT SLOWLY MOVES OFFSHORE. SEAS BUILD UP TO 6-8 FT ON THE SOUTHERN OUTER WATERS TO E OF CAPE COD...AND UP TO 5 FT ON THE EASTERN OUTER WATERS. MAY SEE LINGERING SHOWERS DURING MONDAY ACROSS THE SOUTHERN WATERS.
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&& .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. RI...NONE. MARINE...NONE. && $$ SYNOPSIS...DUNTEN/EVT NEAR TERM...DUNTEN SHORT TERM...DUNTEN LONG TERM...EVT AVIATION...DUNTEN/EVT MARINE...DUNTEN/EVT

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