Area Forecast Discussion
Issued by NWS Boston, MA

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000 FXUS61 KBOX 041434 AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 1034 AM EDT TUE AUG 4 2015 .SYNOPSIS...
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THUNDERSTORMS EXPECTED TODAY...BUT MAINLY ACROSS THE EASTERN HALF OF THE AREA. SOME MAY BECOME SEVERE. DRY...WARM AND LESS HUMID WEATHER ARRIVES THURSDAY. A PERIOD OF UNSETTLED WEATHER IS POSSIBLE THURSDAY NIGHT INTO SATURDAY...BUT CONFIDENCE IS LOW REGARDING THE TIMING AND COVERAGE OF ANY POTENTIAL WET WEATHER.
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&& .NEAR TERM /THROUGH WEDNESDAY/...
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1030 AM UPDATE... DO NOT LET YOUR GUARD DOWN. ADDITIONAL THUNDERSTORM DEVELOPMENT IS EXPECTED LATER TODAY SOME OF WHICH ARE LIKELY TO BE STRONG TO SEVERE. GOING INTO THE ENVIRONMENT: HIGHER THETA-E AIR RESIDES OFFSHORE PUSHED OUT TO SEA BY THIS MORNINGS WEATHER. BUT EXPECTING A REBOUND INTO AFTERNOON AHEAD OF A FRONTAL BOUNDARY SWEEPING SE. HEIGHTS DO STILL RISE WITHIN THE LOW- TO MID-LEVELS AND THERE IS SOME CONCERN THAT ACCOMPANYING SUBSIDENCE COULD SQUASH ACTIVITY AS THE WATER VAPOR LOOP HAS A DRY-SLOT SWEEPING IN...BUT DESPITE THIS THERE IS A STRONG PUSH OF MID-LEVEL ENERGY PER THE LATEST HIGH-RES GUIDANCE ALONG WITH AN ACCOMPANYING JET STREAK THAT YIELDS A DECENT SW LOW-LEVEL JET PUSHING HIGHER THETA-E AND INSTABILITY BACK ACROSS SE NEW ENGLAND AND NEIGHBORING CENTRAL- INTERIOR LOCALES. PWATS OF 1.25 TO 1.50 INCHES NW TO SE TOWARDS DEEPER MOISTURE AND HIGHER THETA-E. FOCUS ON AREAS WHEREVER THERE IS A NOSE OF CONVERGENCE OF THE LOW-LEVEL FLOW / WHEREVER THE ENVIRONMENT CAN DESTABILIZE / AWAY FROM THE DRY PUNCH PER WATER VAPOR TO THE W. SO ROUGHLY PUT THERE IS FOCUS OVER THE E-HALF OF NEW ENGLAND TOWARDS THE SE TOWARDS THE MIDDAY INTO AFTERNOON HOURS. DECENT LAPSE RATES THROUGHOUT THE COLUMN WITHIN WHICH 0-6 KM BULK SHEAR EXCEEDS 50 KTS. SOME TURNING WITHIN THE LOW-LEVEL 0-1/0-3 KM PROFILE PER LATEST HIGH-RES GUIDANCE...OTHERWISE UNI-DIRECTIONAL SW TO NE SHEAR. A FINAL WORD...NOTE THE ENVIRONMENT FROM THE 12Z ALBANY SOUNDING AND THAT OF CHATHAM! MUCAPE VALUES EXCEEDING 2K J/KG SO LONG AS WE CAN MIX OUT THE BOUNDARY LAYER WHICH IS EXPECTED. NOTE ALSO THE SHEAR PROFILE THAT WAS OBSERVED AS ROUGHLY UNI-DIRECTIONAL SW-NE. ALREADY SEEING SPC MESOANALYSIS BECOMING ROBUST WITH MUCAPE VALUES OF 2K J/KG AND EFFECTIVE SHEAR OF 50 KTS. MID-LEVEL LAPSE RATES OF 6.5C/KM. PLENTY OF SUNSHINE TO WARM US UP INTO THE 80S WITH SOME LOCALES NEAR 90. SO WILL GO WITH LIKELY POPS WITH PRIORITIZED THREATS OF THE FOLLOWING: HEAVY RAIN / FREQUENT LIGHTNING / URBAN AND POOR DRAINAGE FLOODING ISSUES / STRONG TO DAMAGING WINDS / SMALL HAIL. THERE IS THE POSSIBILITY OF A TORNADO.
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&& .SHORT TERM /WEDNESDAY NIGHT THROUGH 6 PM WEDNESDAY/... OVERNIGHT... COLD FRONT WILL BE SLOWING TO A NEAR STALL BETWEEN 00Z AND 04Z THIS EVENING JUST OFFSHORE. THIS WILL ALLOW A CONTINUATION OF T-STORM RISK MAINLY ACROSS COASTAL REGIONS UNTIL DRIER AIR MOVES IN FROM THE NW AND CONVECTION SHIFTS S TOWARD BETTER INSTABILITY. THEREFORE...GRADUAL IMPROVEMENT EXPECTED. SOME FOG POSSIBLE WHERE RAINFALL OCCURS. OTHERWISE...TEMPS A LITTLE COOLER...MAINLY IN THE LOWER 60S ACROSS THE AREA...OR EVEN IN THE 50S ACROSS NW MA. WEDNESDAY... CYCLONICALLY CURVED FLOW REMAINS IN PLACE ACROSS THE REGION COMBINED WITH H5 TEMPS ABNORMALLY COLD...AROUND -13C. STALLED FRONTAL BOUNDARY REMAINS TO THE S...BUT ONE FINAL SHORTWAVE WILL BE ROTATING THROUGH TO THE N. THIS MAY LEAD TO SOME SCT SHOWERS/T-STORMS MAINLY N OF THE MASS PIKE. WITH THE VERY COLD H5 TEMPERATURES...THERE IS A RISK FOR HAIL AS WELL. KEY WILL BE HOW MUCH DRY AIR BUILDS THROUGH THE COLUMN. NOT EXPECTING SHOWERS/STORMS TO BE AS WIDESPREAD AS TODAY...BUT SOME LOW CHANCE OR AT LEAST SLIGHT CHANCE POPS ARE NEEDED TO REFLECT THE RISK. WARMER TEMPS REMAIN IN PLACE...MAINLY THE LOW-MID 80S. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... HIGHLIGHTS... * UNSETTLED WEATHER POSSIBLE FRIDAY * TEMPERATURES TRENDING BELOW NORMAL DURING THIS PERIOD OVERALL...THE MODELS CONTINUE TO HAVE RATHER POOR AGREEMENT ON THE DETAILS THROUGH THIS PORTION OF THE FORECAST. THERE IS SOME AGREEMENT ON THE OVERALL PATTERN TREND...WITH A CLOSED MID LEVEL LOW OVER EASTERN CANADA...MOVING INTO THE MARITIMES LATE THIS WEEK. LOOKING AT A PERIOD OF UNSETTLED WEATHER WITH TEMPERATURES TRENDING BELOW NORMAL THROUGH MUCH OF THIS TIME PERIOD. THURSDAY...MUCH OF THE DAY LOOKS TO BE DRY WITH HIGH PRESSURE BUILDING INTO THE AREA. THURSDAY NIGHT THROUGH SATURDAY...THIS LOOKS TO BE THE MOST UNSETTLED TIME WITH A LOW PRESSURE MOVING INTO THE MID ATLANTIC STATES...THEN POSSIBLY UP THE EAST COAST OVER THE 40/70 BENCHMARK SOUTHEAST OF SOUTHERN NEW ENGLAND. THE ECMWF REMAINS MORE BULLISH THAN THE GFS...AND HAS A FASTER TIMING AS WELL. THE GFS ALSO HAS A MORE SOUTHERN TRACK THAN THE GFS. GIVEN THE UNCERTAINTY IN THE DETAILS...WILL KEEP AT LEAST A CHANCE OF RAINFALL...WITH THE GREATEST POPS TOWARD THE SOUTH COAST OF NEW ENGLAND. WITH MOSTLY CLOUDY TO OVERCAST SKIES FOR MUCH OF THIS TIME...EXPECTING BELOW NORMAL TEMPERATURES. SUNDAY AND MONDAY...MUCH OF THIS FORECAST WILL DEPEND ON HOW THE PATTERN FOR FRIDAY AND SATURDAY DEVELOP. IN GENERAL THOUGH... EXPECTING DRIER WEATHER WITH REBOUNDING TEMPERATURES. && .AVIATION /14Z TUESDAY THROUGH SATURDAY/...
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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 WEDNESDAY/... 15Z UPDATE... TODAY...MODERATE CONFIDENCE. SHRA/TSRA DEVELOPING TOWARDS MIDDAY GOING W TO E INTO THE EVENING HRS. STRONG TO SEVERE POTENTIAL. +RA WITH GUSTY WINDS AND POSSIBLE HAIL. BRIEF MVFR / IFR CONDITIONS WITH TSRA. TONIGHT INTO WEDNESDAY...HIGH CONFIDENCE. AFTER STORMS/RAIN SWEEPS OFFSHORE LATE THIS EVENING...EXPECT IMPROVEMENT TO VFR WHICH WILL LINGER INTO THE DAYLIGHT HOURS ON WED. AN ISOLATED SHOWER OR THUNDERSTORM IS THEN POSSIBLE MAINLY N OF THE MASS PIKE ON WED...BUT NOT AS WIDESPREAD AS TUE. KBOS TERMINAL...HIGH CONFIDENCE IN TAF. LOWER CONFIDENCE IN TIMING OF ANY AFTERNOON STORMS. KBDL TERMINAL...HIGH CONFIDENCE IN TAF. LOWER CONFIDENCE IN TIMING OF ANY AFTERNOON STORMS. OUTLOOK /WEDNESDAY NIGHT THROUGH SATURDAY/... WEDNESDAY NIGHT THROUGH THURSDAY...HIGH CONFIDENCE. VFR. LOW PROBABILITY OF A FEW SHOWERS/STORMS ACROSS NW MA WEDNESDAY. ANY STORMS THAT DEVELOP MAY HAVE MVFR/IFR CONDITIONS. THURSDAY NIGHT THROUGH SATURDAY...LOW CONFIDENCE ON TIMING...HIGHER CONFIDENCE ON TRENDS. MVFR/IFR CONDITIONS IN WIDESPREAD RAIN LIKELY SOMETIME DURING THIS PERIOD. VFR BEFORE AND AFTER PERIODS OF RAIN.
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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 TUESDAY NIGHT/... TODAY...MODERATE CONFIDENCE. SW WINDS REMAIN IN PLACE AND WITH SOME GUSTS APPROACHING 25-30 KT AT TIMES. GUSTS COULD APPROACH 45 KT IN AND NEAR THE STRONGER THUNDERSTORMS EXPECTED TO REDEVELOP ACROSS THE WATERS. THIS WILL ALLOW SEAS...WHICH ARE ALREADY RUNNING AROUND 5 FT ON THE S WATERS TO INCREASE...POSSIBLY INCREASING TO AS HIGH AS 7 FT BY THE EVENING. SMALL CRAFT ADVISORIES CURRENTLY OUT REFLECT THIS...SO NO CHANGES. TONIGHT INTO WEDNESDAY...MODERATE CONFIDENCE. FRONT MOVES FURTHER OFFSHORE...OUTSIDE OF ANY STORMS/SHOWERS... WINDS AND SEAS WILL GRADUALLY DIMINISH...SO EXPECT THESE SMALL CRAFT ADVISORIES TO GRADUALLY BE DROPPED THROUGH THE PERIOD. OUTLOOK /WEDNESDAY NIGHT THROUGH SATURDAY/...MODERATE CONFIDENCE. WEDNESDAY NIGHT THROUGH FRIDAY...HIGH CONFIDENCE. QUIET BOATING WEATHER WITH LIGHT WINDS AND SEAS BELOW 5 FEET EXPECTED. RAIN IS LIKELY AT TIMES THURSDAY NIGHT THROUGH FRIDAY...LIMITING VISIBILITIES AT TIMES. FRIDAY NIGHT AND SATURDAY...MODERATE CONFIDENCE. EASTERLY WINDS AND SEAS INCREASE AS LOW PRESSURE PASSES SOUTH OF THE WATERS. SMALL CRAFT ADVISORIES WILL LIKELY BE NEEDED FOR THE OUTER WATERS. RAIN IS LIKELY FRIDAY NIGHT INTO SATURDAY...LIMITING VISIBILITIES AT TIMES.
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&& .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. RI...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR ANZ230>234-236-250-251. SMALL CRAFT ADVISORY UNTIL 8 AM EDT WEDNESDAY FOR ANZ235-237- 254>256. && $$ SYNOPSIS...BELK/DOODY NEAR TERM...BELK/DOODY/SIPPRELL SHORT TERM...DOODY LONG TERM...BELK AVIATION...BELK/DOODY MARINE...BELK/DOODY

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