Area Forecast Discussion
Issued by NWS Boston, MA

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000 FXUS61 KBOX 010740 AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 340 AM EDT MON SEP 1 2014 .SYNOPSIS...
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A WARM HUMID FLOW WILL CONTINUE ACROSS NEW ENGLAND THROUGH TUESDAY WITH SCATTERED SHOWERS AND THUNDERSTORMS EACH DAY. A COLD FRONT WILL MOVE THROUGH TUESDAY NIGHT. LESS HUMID WEATHER WILL THEN FOLLOW FOR WEDNESDAY THROUGH FRIDAY. ANOTHER COLD FRONT MAY BRING A CHANCE OF SHOWERS AND THUNDERSTORMS NEXT SATURDAY.
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&& .NEAR TERM /UNTIL 6 PM THIS EVENING/...
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THROUGH 8 AM... WARM HUMID AIR IN PLACE OVER SOUTHERN NEW ENGLAND WITH LIGHT SOUTHWEST WIND FLOW. THIS WILL SUPPORT AREAS OF FOG THROUGH SUNRISE. THE BEST CHANCE FOR FOG WILL BE ALONG THE SOUTH COAST OF RI AND MASS...AS WELL AS IN THE CT RIVER VALLEY. TEMPERATURES WILL HOLD IN THE UPPER 60S AND LOWER 70S. AN AREA OF SHOWERS/TSTMS PASSING SOUTH OF LONG ISLAND SHOULD PASS SOUTH OF THE ISLANDS TOWARD SUNRISE. THERE IS A LOW CHANCE THAT THE SHOWERS COULD CLIP NANTUCKET. TODAY... WARM HUMID AIR WITH DEWPOINTS IN THE UPPER 60S AND 70S. A FRONT IS STALLED ALONG THE CANADIAN BORDER. MEANWHILE A LEE TROUGH WILL BE POSITIONED NEAR THE MID ATLANTIC COAST. BOTH OF THESE WILL SERVE AS FOCII FOR THUNDERSTORM DEVELOPMENT. SOMEWHAT DRIER AIR MOVES INTO NORTHERN NEW ENGLAND WITH PRECIP WATER VALUES NEAR 1 INCH. MEANWHILE 2 INCH VALUES LINGER ALONG THE SOUTH COAST. THIS MOISTURE WILL BE THE POTENTIAL FUEL FOR ANY DAYTIME CONVECTION. STABILITY PARAMETERS LOOK FAVORABLE FOR TSTMS BUT LIKELY NOT AT SEVERE LEVELS. TOTALS START LOW AND CLIMB TO 46-47 IN THE AFTERNOON WITH HIGHEST VALUES ACROSS CT-RI-SE MASS. THE GFS SHOWS SHOWS SBCAPE REACHING 1000-1500 J/KG ESPECIALLY IN CT. LOW LEVEL HELICITY IS MUCH LOWER THAN SUNDAY...20-30 M2/S2. POPS WILL FAVOR AFTERNOON/EVENING TSTMS WITH HIGHEST VALUES AT THE SOUTH COAST. WITH PRECIP WATER VALUES AT 1.5-2.0 INCHES SOUTH OF THE MASS PIKE...ANY STORMS IN THIS AREA WILL HAVE POTENTIAL FOR HEAVY DOWNPOURS AND POSSIBLE URBAN/POOR DRAINAGE FLOODING. MAX SFC TEMPS WILL AGAIN BE IN THE MID 80S.
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&& .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
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TONIGHT... LINGERING CONVECTION IN THE EVENING BUT DIMINISHING. HIGH HUMIDITY AND LIGHT WIND WILL AGAIN FAVOR DEVELOPMENT OF FOG OVERNIGHT. MIN SFC TEMPS WILL BE NEAR THE DEW POINTS...MAINLY UPPER 60S AND LOWER 70S. TUESDAY... UPPER SHORTWAVE DIGS OVER THE GREAT LAKES WHILE HIGH PRESSURE REMAINS TO OUR EAST. THIS WILL MAINTAIN THE WARM MOIST SOUTHWEST FLOW ACROSS NEW ENGLAND. A COLD FRONT ASSOCIATED WITH THE UPPER SHORTWAVE WILL MOVE EAST THROUGH THE EASTERN GREAT LAKES TO EASTERN NEW YORK BY EVENING. A PRE-FRONTAL TROUGH WILL REMAIN OVER THE HUDSON AND DELAWARE VALLEYS. FAVORABLE JET DYNAMICS REMAIN WELL TO OUR WEST MUCH OF THE DAY...BUT APPROACH WESTERN MASS/SOUTHERN NH LATE. TOTALS ON THE GFS ARE 50-51 WHILE THE ECMWF AND GGEM ARE 47-48. MID LEVEL LAPSE RATES ARE AROUND 6C/KM. SBCAPES ARE 500-1000 J/KG BY THE GFS HINTS AT 1000-1500 J/KG. OVERALL WE WILL FAVOR CHANCE POPS FOR SHOWERS/TSTMS IN THE AFTERNOON WITH THE BEST CHANCE IN WESTERN MASS/SOUTHERN NH AND DIMINISHING VALUES FARTHER EAST. PRECIPITABLE WATER VALUES START AROUND 1.5 INCHES AND CLIMB TO NEAR 2 INCHES...SO LOCALLY HEAVY DOWNPOURS WILL AGAIN BE A CONCERN.
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&& .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
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OVERVIEW AND MODEL PREFERENCES... BROAD RIDGING REMAINS THE DOMINATE FEATURE ACROSS THE EASTERN USA THROUGH MOST OF THIS FORECAST PERIOD. THIS IS MORE TYPICAL FOR THE MIDDLE OF SUMMER RATHER THAN EARLY SEPTEMBER. EARLY IN THIS PERIOD...THERE WILL BE A COUPLE OF FAST MOVING SYSTEMS IN THE BROAD NORTHERN STREAM THAT WILL AFFECT OUR REGION. THIS STRONG RIDGE FINALLY BECOMES ESTABLISHED AROUND MID WEEK ACROSS THE SOUTHERN USA...WITH WARM BUT DRY CONDITIONS THROUGH THE END OF THIS WEEK. SOME QUESTIONS AS TO WHEN THE RIDGING MAY BREAK DOWN...AS MODEL SOLUTIONS LATE IN THE RUN TRY TO BREAK DOWN THE RIDGE WHILE BRINGING A MID-LEVEL CUTOFF LOW ACROSS NORTH CENTRAL CANADA INTO NORTHERN QUEBEC. OVERALL...HAVE FAIRLY GOOD CONFIDENCE WITH MOST OF THIS FORECAST... THOUGH SOME QUESTIONS WITH POSSIBLE CHANGES IN THE STEERING PATTERN OVER THE NORTHERN TIER LATE THIS WEEK. HAVE LEANED TOWARD A BLEND OF AVAILABLE GUIDANCE INTO FRIDAY...THEN PUSHED TOWARD A BLEND OF THE ECENS AND GEFS MEANS WHICH SHOWED A SLOWER BREAKDOWN OF THE RIDGING ACROSS THE REGION...WITH LOWER CONFIDENCE IN THE DETAILS OF THIS FORECAST FOR THIS WEEKEND. DAILIES... WEDNESDAY...EXPECTING DRIER AIR TO SLOWLY ARRIVE DURING THE DAY ON LIGHT WEST WINDS. HIGH PRESSURE WILL BUILD OUT OF THE APPALACHIANS. TEMPERATURES WILL REMAIN WARM FOR THIS TIME OF YEAR...WITH A GENERAL WEST WIND FLOW THROUGHOUT THE LAYER. COULD SEE SOME SHOWERS LINGER ACROSS CAPE COD AND THE ISLANDS DURING THE EARLY MORNING HOURS. THURSDAY AND FRIDAY...EXPECTING DRY AND MILD CONDITIONS CONTINUING WITH DEWPOINTS FALLING INTO THE 50S...THOUGH AROUND 60 ALONG THE IMMEDIATE COAST. CENTER OF HIGH PRESSURE SHIFTS OFFSHORE...RESULTING AND LIGHT SOUTHWEST WINDS. THIS SHOULD MEAN SLIGHT ABOVE NORMAL TEMPERATURES AWAY FROM THE IMMEDIATE COASTS. SATURDAY AND SUNDAY...LOTS OF QUESTIONS DURING THIS TIMEFRAME... MAINLY DUE TO TIMING ISSUES OF A COLD FRONT. KEPT MENTION OF CHANCE POPS AS A COLD FRONT TRIES TO CROSS SOUTHERN NEW ENGLAND THIS WEEKEND. LOW CONFIDENCE WITH THIS FEATURE. HIGH PRESSURE SHOULD EVENTUALLY RETURN LATER SUNDAY.
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&& .AVIATION /07Z MONDAY THROUGH FRIDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH MONDAY NIGHT/...HIGH CONFIDENCE IN TRENDS BUT LOWER CONFIDENCE IN PRECISE DETAILS AND TIMING. OVERNIGHT...AREAS OF IFR IN FOG AND STRATUS OVERNIGHT. BEST CHANCE FOR THIS WILL BE ALONG THE SOUTH COAST AND ISLANDS...AND ALONG CAPE COD BAY. ALSO A GOOD CHANCE FOR IFR/LIFR IN THE CT RIVER VALLEY. TODAY...IFR CIGS MAY LINGER ALONG THE SOUTH COAST THROUGH MOST OF THE DAY. NORTH OF THERE CONDITIONS IMPROVE TO VFR. ANOTHER DISTUBANCE PASSES SOUTH OF NEW ENGLAND BUT MAY GENERATE ANOTHER ROUND OF SHOWERS/TSTMS ACROSS CT/RI/SE MASS THIS AFTERNOON/EVENING WITH LOCALLY HEAVY DOWNPOURS POSSIBLE. BRIEF MVFR/IFR IN ANY TSTMS. TONIGHT...EVENING SHOWERS/TSTMS ESPECIALLY OVER THE CAPE AND ISLANDS. BRIEF MVFR/IFR IN ANY STORMS. QUIET WEATHER THE REMAINDER OF THE NIGHT WITH AREAS OF IFR/LIFR IN STRATUS AND FOG. BEST CHANCE WILL AGAIN BE ALONG THE SOUTH COAST AND ISLANDS AS WELL AS THE CT RIVER VALLEY. TUESDAY...MORNING FOG AND LOW CONDITIONS BURN OFF. VFR THROUGH MUCH OF THE DAY. INCREASING CLOUDS FROM THE WEST DURING THE AFTERNOON/EVENING WITH POTENTIAL FOR BRIEF MVFR IN SCATTERED THUNDERSTORMS. KBOS TERMINAL...HIGH CONFIDENCE IN TAF REGARDING TRENDS BUT LOWER CONFIDENCE ON PRECISE DETAILS AND TIMING. KBDL TERMINAL...HIGH CONFIDENCE IN TAF REGARDING TRENDS BUT LOWER CONFIDENCE ON PRECISE DETAILS AND TIMING. OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY... TUESDAY NIGHT...MODERATE CONFIDENCE. PRECIP SHOULD TAPER OFF AFTER MIDNIGHT. PATCHY FOG RETURNS AFTER 05Z-06Z WITH MVFR-IFR VSBYS IN NORMALLY PRONE INLAND LOCATIONS. WEDNESDAY THROUGH FRIDAY...MODERATE CONFIDENCE. EXPECTING MAINLY VFR CONDITIONS AS HIGH PRESSURE BUILDS IN. LOCAL MVFR-IFR VSBYS AND CIGS IN LATE NIGHT PATCHY FOG AND STRATUS. MAIN AREAS OF CONCERN WILL BE THE TYPICALLY PRONE LOCATIONS ACROSS THE FAR INTERIOR /SOUTHWEST NH AND NORTH CENTRAL AND WESTERN MA/. && .MARINE...
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FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. MODERATE CONFIDENCE THROUGH TUESDAY. TODAY... HIGH PRESSURE OFFSHORE AND LOW PRESSURE OVER THE GREAT LAKES WILL MAINTAIN A SOUTHWEST WIND FLOW ACROSS THE WATERS THROUGH TUESDAY. WINDS WILL REMAIN AT OR BELOW 20 KNOTS. SEAS WILL START AROUND 5 FEET ON THE OUTER WATERS BUT WILL DIMINISH THROUGH THE DAY. WE HAVE MAINTAINED SMALL CRAFT ADVISORY ON THE SOUTHERN OUTER WATERS THROUGH THE DAY DUE TO THE LINGERING ROUGH SEAS. A FEW THUNDERSTORMS WILL MOVE ACROSS SOUTHERN NEW ENGLAND WITH THE BEST CHANCE ON THE WATERS OCCURING SOUTH OF BOSTON. TONIGHT... EVENING THUNDERSTORMS DIMINISH EARLY AT NIGHT. LIGHT SOUTHWEST FLOW WILL ALLOW AREAS OF FOG OVERNIGHT WITH POOR VISIBILITY. TUESDAY... AREAS OF FOG WILL START THE MORNING...WITH VISIBILITY IMPROVING DURING THE MORNING. SHOWERS AND THUNDERSTORMS WILL MOVE INTO WESTERN NEW ENGLAND DURING THE AFTERNOON AND MAY THREATEN THE COASTAL WATERS TOWARD EVENING. TSTMS COULD CAUSE STRONG WIND GUSTS...OTHERWISE EXPECT WINDS AND SEAS TO REMAIN BELOW SMALL CRAFT LEVELS. OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY... MODERATE CONFIDENCE. EXPECTING WINDS AND SEAS TO REMAIN BELOW SMALL CRAFT CRITERIA THROUGH THIS PERIOD. MAY SEE SOME SOUTHWEST WIND GUSTS UP TO 20 KT TUE NIGHT...BEFORE SHIFTING TO W-NW AND DIMINISHING BY WED MORNING.
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&& .BOX WATCHES/WARNINGS/ADVISORIES...
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CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ254>256.
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&& $$ SYNOPSIS...WTB/KJC NEAR TERM...WTB SHORT TERM...WTB LONG TERM...BELK AVIATION...WTB/BELK MARINE...WTB/BELK

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