Area Forecast Discussion
Issued by NWS Boston, MA

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000 FXUS61 KBOX 292034 AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 433 PM EDT FRI MAY 29 2015 .SYNOPSIS...
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A MAINLY DRY...WARM AND SOMEWHAT HUMID AFTERNOON IS IN STORE FOR MOST THE REGION FOR SATURDAY. A COLD FRONT WILL SLOWLY MOVE ACROSS THE REGION SUNDAY...THEN STALL SOUTH OF NEW ENGLAND EARLY NEXT WEEK. THIS WILL BRING A CHANCE OF SHOWERS AND A FEW THUNDERSTORMS SUNDAY...AND A PERIOD OF RAIN EARLY NEXT WEEK. HIGH PRESSURE BRINGS DRY WEATHER FOR THE LATTER PART OF THE WEEK.
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&& .NEAR TERM /UNTIL 6 PM THIS EVENING/...
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A VERY TRICKY FORECAST TONIGHT IN REGARDS TO LOW CLOUD POTENTIAL. LOW CLOUDS HAVE BEEN SITTING JUST OFF THE EASTERN MA COAST MUCH OF THE AFTERNOON. HOWEVER...SOLAR HEATING HAS KEPT THEM BASICALLY JUST OFFSHORE...EXCEPT AFFECTING PORTIONS OF COASTAL PLYMOUTH COUNTY AND THE OUTER-CAPE FOR A TIME. GIVEN EASTERLY WINDS ARE EXPECTED TO BECOME SOUTHERLY THIS EVENING...DO NOT EXPECT THESE LOW CLOUDS TO REALLY MOVE INLAND. ITS POSSIBLE THAT THEY MAKE IT ONSHORE FOR AN HOUR OR TWO TOWARDS SUNSET...ESPECIALLY ACROSS THE NORTH SHORE WITH SURFACE WINDS TURNING SOUTH BUT PROBABLY SHORT LIVED. OTHERWISE...THE FOCUS OF LOW CLOUDS/FOG WILL TURN TO THE SOUTH COAST/CAPE AND ISLANDS. SATELLITE IMAGERY SHOWS LOW CLOUDS SITTING SOUTH OF LONG ISLAND AND AS WINDS TURN SOUTHERLY AND BOUNDARY LAYER COOLS...SHOULD SEE THEM ADVECT NORTHWARD. LOW CONFIDENCE ON HOW FAR NORTH THESE LOW CLOUDS ADVECT...BUT PROBABLY AFFECT THE SOUTH COAST AND PERHAPS AS FAR NORTH AS THE MA PIKE. SOME FOG IS ALSO EXPECTED AND CAN/T RULE OUT A PERIOD OF DENSE FOG ACROSS SOUTHEAST NEW ENGLAND...BUT CONFIDENCE ON THAT IS LOW. OTHERWISE...A DRY NIGHT OTHER THAN PERHAPS A BIT OF MIST TOWARD DAYBREAK ALONG WITH THE FOG ACROSS THE SOUTHEAST NEW ENGLAND COAST. LOW TEMPS MAINLY IN THE UPPER 50S TO THE LOWER 60S.
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&& .SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
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***A WARM AND SOMEWHAT HUMID SATURDAY AFTERNOON IS ON TAP INLAND FROM THE SOUTH COAST*** HIGH PRESSURE MOVING OFF THE COAST WILL ALLOW A WARMER AND MORE HUMID AIRMASS TO OVERSPREAD SOUTHERN NEW ENGLAND ON SATURDAY. LOW CLOUDS THAT FORM SOUTH OF MA PIKE SHOULD SCOUR OUT BY SATURDAY AFTERNOON IF NOT EARLIER FOR MOST OF THE REGION. HOWEVER...LOW CLOUDS AND FOG PATCHES MAY LINGER ACROSS THE IMMEDIATE SOUTH COAST/CAPE/ISLANDS. OTHERWISE...HIGH TEMPS SHOULD REACH INTO THE MIDDLE TO UPPER 80S TO THE NORTHWEST OF A BOSTON TO PROVIDENCE LINE. THE WARMEST OF THOSE READINGS SHOULD BE FOUND IN THE MERRIMACK VALLEY. TO THE SOUTHEAST OF A BOSTON TO PROVIDENCE LINE...GUSTY SOUTHWEST WINDS WILL HOLD HIGH TEMPS IN THE 70S TO NEAR 80. IN FACT...SOUTHWEST WIND GUSTS OF 20 TO 30 MPH ARE EXPECTED FOR MOST OF THE REGION SATURDAY AFTERNOON WITH GOOD MIXING. UPPER LEVEL RIDGING SHOULD RESULT IN MAINLY A DRY DAY ACROSS THE REGION. BEST FORCING/INSTABILITY AND DYNAMICS WILL BE WELL TO OUR NORTHWEST WITH AN APPROACHING COLD FRONT. JUST A LOW RISK OF A SPOT SHOWER/THUNDERSTORM LATE SATURDAY AFTERNOON/EARLY EVENING ACROSS NORTHWEST MA. SATURDAY NIGHT... A COLD FRONT WILL BE SLOWLY APPROACHING OUR REGION FROM THE WEST. A SOUTHWEST LOW LEVEL JET WILL RESULT IN A MILD NIGHT...WITH LOW TEMPS ONLY DROPPING TO BETWEEN 60 AND 65. DRY WEATHER SHOULD DOMINATE THE FIRST PART OF THE NIGHT...BUT WE MAY SEE SOME SCATTERED SHOWERS AND PERHAPS AN EMBEDDED THUNDERSTORM OR TWO DEVELOP OVERNIGHT. THIS IS RESPONSE TO LOW LEVEL JET AND A BURST OF INSTABILITY. ACTIVITY WILL PROBABLY BE HIT AND MISS THROUGH DAYBREAK SUNDAY...WITH THE BULK OF IT TO THE NORTHWEST OF I-95. BULK OF LOW CLOUDS SHOULD BE CONFINED TO THE SOUTHEAST NEW ENGLAND COAST. ENOUGH WIND IN THE BOUNDARY LAYER MAY PREVENT A LOT OF FOG FROM DEVELOPING...BUT STILL CAN NOT RULE OUT SOME DEVELOPING.
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&& .LONG TERM /SUNDAY THROUGH FRIDAY/...
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OVERVIEW AND MODEL PREFERENCES... OVERALL MODEL TRENDS HAVE NOT DEVIATED MUCH FROM PRIOR RUNS. CONFIDENCE GROWING IN THE TIMING OF A SLOW-MOVING COLD FRONT AS IT CROSSES SOUTHERN NEW ENGLAND LATER THIS WEEKEND. MID-LEVEL ATLANTIC RIDGE SHIFTS FARTHER OFFSHORE THIS WEEKEND. THIS WILL PERMIT A BRIEF MID-LEVEL TROUGH TO MOVE BY DURING THE MIDDLE OF NEXT WEEK. AS TYPICAL WITH THESE FEATURES...AT THAT TIME RANGE IN THE FORECAST...THERE ARE PLENTY OF TIMING DIFFERENCES YET TO BE RESOLVED. LEANED TOWARD THE CONSENSUS SOLUTION TO SMOOTH OVER THE TIMING DIFFERENCES DURING THIS PORTION OF THE FORECAST. DETAILS... SUNDAY...THIS CONTINUES TO LOOK LIKE THE MOST LIKELY PERIOD FOR A MORE WIDESPREAD RAINFALL. PRECIPITABLE WATER DURING THIS TIME REMAINS 1.7 TO 1.8 INCHES...SO COULD ALSO SEE SOME HEAVY DOWNPOURS. AT THIS POINT...THINKING A COLD FRONT WILL PUSH NEAR OR SOUTH OF THE MASS PIKE SOMETIME SUNDAY NIGHT...BUT WILL TEND TO SLOW DOWN AS IT MOVES FARTHER SOUTH. THIS WILL LOWER THE RISK FOR THUNDERSTORMS AS MORE STABLE AIR MOVES INTO NORTHERN MA SUNDAY NIGHT...BUT STILL COULD SEE SPOTTY CONVECTION ACROSS N CT/RI/SE MA. SHOWERS LOOK TO TAPER OFF ACROSS THE ROUTE 2 AREA BY AROUND SUNRISE MONDAY...BUT TIMING IS STILL IN QUESTION. MONDAY...A LOT OF UNCERTAINTY CONTINUES AS MOVING THIS FRONT ACROSS THE REGION...WITH TIMING DIFFERENCES AMONGST THE MODEL SUITE. LOOKS LIKE A CHANCE FOR SHOWERS LINGERS INTO MONDAY NIGHT...MAINLY ACROSS NORTHERN CT/RI/SOUTHEASTERN MA. WINDS DO START TO SHIFT AROUND TO N-NE ACROSS CENTRAL AND NORTHERN MA...SO THIS WILL CUT BACK ON THUNDERSTORM ACTIVITY AS COOLER AIR MOVES IN. FOR NOW...CONTINUED TO TAPER OFF RAINFALL BY MONDAY NIGHT ACROSS MOST AREAS...BUT DO LINGER IT ALONG THE S COAST THROUGH AT LEAST MIDNIGHT MON NIGHT. IT WILL BE MUCH COOLER THAN WHAT IT HAS BEEN RECENTLY...WITH HIGHS ONLY IN THE 60S. SOME LOCATIONS ALONG THE EAST COAST MAY NOT EVEN BREAK 60 WITH ONSHORE WINDS. TUESDAY-WEDNESDAY...SHOWERS SHOULD FINALLY PUSH OFF THE SOUTH COAST BY AROUND MIDDAY TUESDAY AT THE LATEST. NORTHEAST WINDS INCREASE AS A HIGH PRESSURE CROSSES NORTHERN NEW ENGLAND DURING THIS TIMEFRAME. HAVE CONTINUED A DRY AND SEASONABLE FORECAST FOR WEDNESDAY.
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&& .AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
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FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. TONIGHT...LOW TO MODERATE CONFIDENCE. LOW CLOUDS SITTING JUST OFF THE EASTERN MA COAST LATE THIS AFTERNOON. WINDS ALONG THE EASTERN MA COAST TURN SOUTH SOUTHWEST THIS EVENING...SO THAT SHOULD LIMIT LOW CLOUDS COMING IN FROM THE EAST. THEREFORE...EVEN IF THEY DO GET INTO BOSTON THEY WILL BE SHORT LIVED AND MAY REMAIN JUST OFF THE COAST. THE BIGGER CONCERN THEN TURNS TO LOW CLOUDS/FOG PATCHES THAT MAY DEVELOP ALONG THE SOUTH COAST AND ESPECIALLY CAPE/ISLANDS. AGAIN...CONFIDENCE IS LOW SO WILL HAVE TO MONITOR CLOSELY. SATURDAY...MODERATE CONFIDENCE. ANY LOW CLOUDS/FOG PATCHES SOUTH OF PIKE PROBABLY SCOUR OUT BY LATE MORNING/EARLY AFTERNOON...EXCEPT CAPE/ISLANDS WHERE THEY MAY LINGER INTO THE AFTERNOON. DRY WEATHER EXPECTED...ALTHOUGH THERE IS A LOW RISK OF A SPOT SHOWER/THUNDERSTORM ACROSS NORTHWEST MA LATE IN THE AFTERNOON/EARLY EVENING. SATURDAY NIGHT...MODERATE CONFIDENCE. MAINLY VFR TO MARGINAL MVFR CIGS EXCEPT FAR SOUTHEAST NEW ENGLAND COAST WHERE IFR CIGS/VSBYS ARE POSSIBLE. SCATTERED SHOWERS AND PERHAPS A THUNDERSTORM OR TWO WILL BE POSSIBLE MAINLY ACROSS THE INTERIOR WITH THE HIGHER RISK DURING THE OVERNIGHT HOURS. KBOS TERMINAL...LOW CONFIDENCE IN TAF EARLY THIS EVENING. IFR CIGS SITTING JUST EAST OF THE TERMINAL AT LATE AFTERNOON. GIVEN WINDS TURNING SOUTH SOUTHWEST EARLY THIS EVENING...THEY MAY NEVER MAKE IT INTO THE TERMINAL. HOWEVER...ITS POSSIBLE THAT THEY DO FOR AN HOUR OR TWO SINCE THEIR SO CLOSE AND WILL HAVE TO CLOSELY MONITOR. KBDL TERMINAL...LOW TO MODERATE CONFIDENCE IN TAF. MVFR TO IFR CIGS MAY DEVELOP AFTER MIDNIGHT BUT UNCERTAIN. 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 SUNDAY NIGHT...WHICH MAY GUST UP TO AROUND 20 KT ALONG THE SOUTH COAST. SHOWERS LINGER SUNDAY NIGHT. MONDAY...SCT SHOWERS LINGERING WITH LOCAL MVFR CONDITIONS EARLY. CONDITIONS WILL IMPROVE FROM N-S DURING THE DAY...EXCEPT ALONG THE S COAST...WHERE SOME SHOWERS WILL LIKELY LINGER. MAY SEE BRIEF MVFR IN ANY SHOWERS. 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 THOSE SHOULD MOVE OFFSHORE. NE WIND GUSTS TO 25 KT STILL POSSIBLE ACROSS THE OUTER CAPE AND ISLANDS.
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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 THROUGH FRIDAY NIGHT/... TONIGHT...MODERATE TO HIGH CONFIDENCE. WEAK PRESSURE GRADIENT WILL KEEP WINDS/SEAS BELOW SMALL CRAFT ADVISORY THRESHOLDS. HOWEVER...AREAS OF FOG MAY DEVELOP OVERNIGHT ACROSS OUR SOUTHERN WATERS BUT ITS UNCERTAIN IF IT WILL BECOME DENSE. SATURDAY...MODERATE TO HIGH CONFIDENCE. EXCELLENT MIXING OVER THE LAND WILL GENERATE NEAR SHORE SMALL CRAFT WIND GUSTS OF 25 TO 30 KNOTS SATURDAY AFTERNOON. IN ADDITION...SOUTHEAST SWELL WILL GENERATE 5 FOOT SEAS ACROSS THE OUTER-WATERS. THEREFORE...SMALL CRAFT HEADLINES POSTED FOR ALL WATERS. AREAS OF FOG MAY BE LOCALLY DENSE IN THE MORNING ALONG THE SOUTH COAST...SHOULD IMPROVE SOMEWHAT BY AFTERNOON. SATURDAY NIGHT...MODERATE TO HIGH CONFIDENCE. NEAR SHORE SMALL CRAFT WIND GUSTS SHOULD DIMINISH SATURDAY EVENING. HOWEVER...5 FOOT SWELL WILL CONTINUE ACROSS THE OUTER-WATERS. SOME FOG POSSIBLE SAT NIGHT...BUT PROBABLY NOT AS WIDESPREAD AS TONIGHT GIVEN SOME MORE BOUNDARY LAYER WIND. OUTLOOK...SUNDAY THROUGH TUESDAY...MODERATE CONFIDENCE. SUNDAY...COLD FRONT SLOWLY APPROACHES THE WATERS. MAY SEE BRIEF GUSTS TO 25 KT AS FRONT SLOWLY MOVES SOUTH SUNDAY. THIS FRONT WILL LIKELY STALL NEAR OR JUST S OF THE S COAST SUNDAY NIGHT. WINDS SHIFT TO E-NE AS THIS FRONT PASSES. AREAS OF SHOWERS WITH SCT THUNDERSTORMS. LOCAL VSBY RESTRICTIONS. MONDAY-TUESDAY...EXPECTING MAINLY NE WINDS. GUSTS TO 25 KT ACROSS THE SOUTHERN OPEN WATERS AS THIS 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...SMALL CRAFT ADVISORY FROM NOON TO 10 PM EDT SATURDAY FOR ANZ230>237-251. SMALL CRAFT ADVISORY FROM 2 PM SATURDAY TO 8 AM EDT SUNDAY FOR ANZ250-254>256. && $$ SYNOPSIS...FRANK/WTB NEAR TERM...FRANK SHORT TERM...FRANK LONG TERM...WTB AVIATION...FRANK/WTB MARINE...FRANK/WTB

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