Area Forecast Discussion
Issued by NWS Boston, MA

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000 FXUS61 KBOX 231704 AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 104 PM EDT THU OCT 23 2014 .SYNOPSIS... A POWERFUL EARLY SEASON COASTAL STORM WILL PASS SOUTHEAST OF NANTUCKET THIS EVENING. RAIN WILL BECOME MORE SHOWERY THIS AFTERNOON BUT STRONG WINDS WILL CONTINUE TO AFFECT EASTERN NEW ENGLAND. SHOWERS CONTINUE TO DIMINISH FRIDAY AS THE STORM SLOWLY PULLS AWAY FROM NEW ENGLAND. SHOWERS POSSIBLE AGAIN SATURDAY EVENING AND OVERNIGHT AS LOW PRES MOVES INTO SOUTHERN QUEBEC. DRY AND SEASONABLY COOL WEATHER RETURNS SUNDAY INTO EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/...
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* CONDITIONS SLOWLY IMPROVE THROUGH TONIGHT * REGIONAL RADAR MOSAIC SHOWS MAIN BAND OF HEAVY RAIN ASSOCIATED WITH MID LEVEL DEFORMATION ZONE HAS SHIFTED INTO EASTERN NY AND CENTRAL NEW ENGLAND EARLY THIS AFTERNOON. IN ITS WAKE SCATTERED SHOWERS WERE ROTATING WESTWARD AROUND UPPER LOW S OF NEW ENGLAND WHERE AIRMASS HAS BECOME MARGINALLY UNSTABLE. HIGH-RES MODELS HAVE A GOOD HANDLE ON THIS AND HAVE A FEW HUNDRED J/KG OF ML/MUCAPE THIS AFTERNOON...WHICH WILL HELP MORE ACTIVITY DEVELOP THROUGH LATE AFTERNOON...ESPECIALLY AROUND CAPE COD AND ISLANDS. NOT LOOKING FOR ANY SEVERE WEATHER...BUT HIGHER CORES COULD PRODUCE STRONG WIND GUSTS AS WELL AS BRIEF DOWNPOURS. ACTIVITY WILL DIMINISH THIS EVENING AS LOW PASSES SE OF NEW ENGLAND. MODELS POINT TO A SECONDARY SURGE OF WIND AS WINDS SHIFT MORE TO N/NW...ESPECIALLY NEAR COAST. AS A RESULT WE WILL KEEP WIND ADVISORY POSTED...THOUGH STRONGEST WINDS APPEAR MORE LIKELY TO OCCUR UNTIL 7 OR 8 PM. CYCLONIC FLOW AND LEFTOVER MOISTURE WILL KEEP CLOUDS LOCKED IN TONIGHT ALONG WITH FEW SHOWERS. LOWS WILL DROP BACK INTO 40S/50S.
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&& .SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
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GRADUAL IMPROVEMENT FRI AS LOW SLOWLY PULLS TOWARD MARITIMES. MAY SEE FEW LEFTOVER SHOWERS ESPECIALLY THU MORNING AND CLOSER TO COAST. CROSS SECTIONS INDICATE LITTLE HOPE FOR SIGNIFICANT CLEARING UNTIL FRI NIGHT...SO CLOUDS WILL DOMINATE UNTIL THEN... ALTHOUGH SOME BREAKS OF SUN ARE CERTAINLY POSSIBLE IN WESTERN NEW ENGLAND. STAYED CLOSE TO BLEND OF MODEL GUIDANCE FOR TEMPS...WHICH GIVES HIGHS IN 50S THU AND BACK INTO 40S THU NIGHT.
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&& .LONG TERM /SATURDAY THROUGH WEDNESDAY/... * SHOWERS POSSIBLE AGAIN SATURDAY AS LOW PRES MOVES INTO QUEBEC * MAINLY DRY AND SEASONABLE WEATHER EARLY NEXT WEEK OVERALL THE 12Z MODEL SUITE IS IN FAIRLY GOOD AGREEMENT THROUGH THE LONG TERM. THERE ARE SOME DISCREPANCIES IN THE MESOSCALE DETAILS BUT OTHERWISE THEY ARE IN GOOD AGREEMENT. AFTER THE COASTAL STORM CURRENTLY AFFECTING THE REGION MOVES AWAY FROM SOUTHERN NEW ENGLAND...THE WEATHER STARTS TO DRY OUT AND BECOME MORE SEASONABLE. THERE ARE A COUPLE OF COLD FRONTS EXPECTED TO MOVE THROUGH THE REGION AND EACH OF THESE MAY BRING SOME SHOWERS WITH THEM. SATURDAY...ANOTHER UPPER LEVEL TROUGH MOVES OVER THE NORTHEAST WITH LOW PRESSURE MOVING THROUGH SOUTHERN QUEBEC AND INTO THE MARITIMES. THE MODELS DON/T SHOW A WHOLE LOT OF MOISTURE OR A BIG WIND SHIFT WITH THIS FRONT BUT WE COULD SEE SOME SHOWERS. THE GFS HAS A STRONGER LOW LEVEL JET THAN THE ECMWF WHICH COULD ENHANCE THE AMOUNT OF RAINFALL BUT THERE IS STILL MUCH TO BE SEEN WITH THIS SYSTEM. SUNDAY THROUGH TUESDAY...HIGH PRESSURE STARTS TO BUILD INTO SOUTHERN NEW ENGLAND BRINGING DRY AND SEASONABLE WEATHER. TEMPERATURES BEGIN TO CLIMB AND MAY WARM TO WELL ABOVE NORMAL BY TUESDAY. WEDNESDAY...LOW PRESSURE MOVING THROUGH THE GREAT LAKES AND INTO QUEBEC MAY BRING A COLD FRONT THROUGH SOUTHERN NEW ENGLAND. ANOTHER CHANCE OF SOME SHOWERS POSSIBLE WITH THIS FRONT BUT PLENTY OF UNCERTAINTY. && .AVIATION /18Z THURSDAY 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 THU NIGHT/...MODERATE CONFIDENCE. NOT MUCH CHANGE IN CONDITIONS THROUGH EARLY TONIGHT WITH MVFR/IFR CIGS...ALTHOUGH VFR CIGS MORE LIKELY AROUND CAPE COD AND ISLANDS AND POINTS OFFSHORE. SHOULD SEE RETURN TO IFR CIGS NEAR COAST TONIGHT WITH MVFR CIGS FARTHER INLAND. SCATTERED SHOWERS/ISOLATED THUNDER MAINLY AROUND CAPE COD AND ISLANDS WITH MVFR CIGS/VSBYS. GUSTY N/NW WINDS TO 35KT ESPECIALLY NEAR COAST THROUGH 00Z. SLOW IMPROVEMENT THU WITH MVFR/IFR CIGS IN MORNING GIVING WAY TO VFR CIGS BY AFTERNOON FROM W TO E. VFR THU NIGHT AS CLEARING WORKS INTO NEW ENGLAND. KBOS...MODERATE CONFIDENCE. LOWER-END MVFR CIGS MOST LIKELY THROUGH THIS EVENING BEFORE CIGS DROP TO IFR TONIGHT. KBDL...HIGH CONFIDENCE. OUTLOOK...SATURDAY THROUGH MONDAY... MODERATE CONFIDENCE. VFR. LOW PROBABILITY OF SCATTERED SHOWERS SATURDAY.
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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/... * CONDITIONS GRADUALLY IMPROVE * COASTAL STORM PASSES SE OF NANTUCKET THIS EVENING AND TO MARITIMES THU AND THU NIGHT. THIS WILL BRING GRADUALLY DIMINISHING WINDS AND ESPECIALLY SEAS...WHICH WILL TAKE A COUPLE OF DAYS TO SUBSIDE. MAINTAINED GALE WARNINGS ON MOST WATERS THROUGH TONIGHT AS WE EXPECT ANOTHER SURGE OF N GALES LATER THIS AFTERNOON AND EVENING...BEFORE WINDS DIMINISH TONIGHT AND THU. SCATTERED SHOWERS AND ISOLATED STORMS THROUGH THIS EVENING... ESPECIALLY AROUND CAPE COD AND ISLANDS. OTHERWISE FEW LEFTOVER SHOWERS THU MORNING. OUTLOOK...SATURDAY THROUGH MONDAY... SATURDAY AND SUNDAY...MODERATE CONFIDENCE. AFTER A BRIEF LULL...SEAS AND WINDS WILL INCREASE AHEAD OF A COLD FRONT. SMALL CRAFT ADVISORIES WILL LIKELY BE NEEDED FOR AT LEAST A PORTION OF THE WATERS. MONDAY...MODERATE CONFIDENCE. WINDS AND SEAS DIMINISH AS HIGH PRESSURE BUILDS OVER THE WATERS.
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&& .TIDES/COASTAL FLOODING... LAST NIGHT/S HIGH TIDE YIELDED A STORM SURGE OF 1.5 FT TO 2.0 FT. THIS COMBINED WITH LARGE WAVE ACTION RESULTED IN WIDESPREAD MINOR COASTAL FLOODING/INUNDATION FROM PLYMOUTH COUNTY NORTHWARD. BOTH ETSS AND ESTOFS ARE ABOUT 50% TOO LOW WITH THEIR SURGE VALUES WHEN COMPARED TO CURRENT OBSERVATIONS. THUS HAVE INCREASED GUID BY 50 PERCENT. WE ARE NOW RAMPING UP TO THE LATE MORNING/MIDDAY HIGH TIDE CYCLE. PRIOR STORM SURGE FORECAST LOOKS GOOD AND HAVE NOT CHANGED. AT 0945 EDT THE SURGE WAS RUNNING AT 2 FEET AT BOS...ABOUT TWICE AS HIGH AS THE GUIDANCE. WAVES JUST OFFSHORE RUNNING 16 TO 18 FEET. THE NNE GRADIENT APPEARS TO BE RETIGHTENING FOR A PERIOD AS ADVERTISED BY SHORT TERM MODELS AND THINK WAVES WILL HOLD AT THESE HEIGHTS OR POSSIBLY EVEN INCREASE ANOTHER FOOT OR TWO BEFORE SUBSIDING THIS EVENING. THE ASTRONOMICAL TIDE IS ABOUT A HALF FOOT HIGHER TODAY THAN LAST NIGHT AND WILL ALLOW WAVE ACTIVITY TO RUNUP SOMEWHAT FURTHER ALONG THE BEACH. HENCE...THE IMPACT COULD BE A LITTLE HIGHER THAN WHAT WAS EXPERIENCED LAST NIGHT. ALSO...WE HAVE THE ISSUE OF THIS BECOMING A FAIRLY LONG DURATION EVENT WITH CONTINUED EROSION OF THE DUNE SLOPES ALONG SANDY BEACH AREAS. WILL KEEP THE COASTAL FLOOD ADVISORY IN PLACE FOR SALISBURY TO CAPE ANN AND HULL TO PLYMOUTH. OUR GREATEST CONCERN CONTINUES TO BE BEACH EROSION IN THE SALISBURY AND PLUM ISLAND AREA. THERE MAY BE SOME SPLASHOVER AND MINOR BEACH EROSION FOR THE HIGH TIDE TONIGHT BUT DO NOT BELIEVE IT WILL REACH AN ADVISORY LEVEL. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...WIND ADVISORY UNTIL 11 PM EDT THIS EVENING FOR CTZ004. MA...WIND ADVISORY UNTIL 11 PM EDT THIS EVENING FOR MAZ005>007- 012>021. COASTAL FLOOD ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR MAZ007-019. NH...WIND ADVISORY UNTIL 11 PM EDT THIS EVENING FOR NHZ012. RI...WIND ADVISORY UNTIL 11 PM EDT THIS EVENING FOR RIZ001>007. MARINE...SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR ANZ231>234-236-254-255. GALE WARNING UNTIL 11 PM EDT THIS EVENING FOR ANZ230-250-251- 256. GALE WARNING UNTIL 10 PM EDT THIS EVENING FOR ANZ235-237. && $$ SYNOPSIS...JWD NEAR TERM...JWD SHORT TERM...JWD LONG TERM...RLG AVIATION...JWD MARINE...JWD TIDES/COASTAL FLOODING...THOMPSON

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