Area Forecast Discussion
Issued by NWS Boston, MA

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000 FXUS61 KBOX 300636 AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 235 AM EDT WED JUL 30 2014 .SYNOPSIS... MAINLY DRY AND LESS HUMID WEATHER IS EXPECTED TONIGHT INTO WEDNESDAY. A FEW SHOWERS AND PERHAPS A THUNDERSTORM ARE POSSIBLE THU AND FRI...BUT MOST OF THE TIME WILL FEATURE DRY WEATHER. A PERIOD OF STEADY RAIN IS POSSIBLE SOMETIME THIS WEEKEND IF LOW PRESSURE TRACKS CLOSE ENOUGH TO THE COAST...BUT CONFIDENCE IS LOW. && .NEAR TERM /UNTIL 6 AM THIS MORNING/...
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235 AM UPDATE... A SCATTERED TO BROKEN DECK OF MID LEVEL CLOUDINESS WILL CONTINUE TO AFFECT THE REGION THROUGH DAYBREAK. ENOUGH BREAKS IN THE CLOUD COVER COMBINED WITH LIGHT WINDS/DRY AIRMASS WILL ALLOW FOR COOL TEMPS OVERNIGHT FOR LATE JULY. LOWS BY DAYBREAK WILL BE WELL DOWN INTO THE 50S ACROSS MUCH OF THE REGION WITH PERHAPS SOME UPPER 40S ACROSS THE NORMALLY COOLEST OUTLYING LOCATIONS OF WESTERN MA/SOUTHWEST NH. THE MILD SPOTS WILL BE THE URBAN HEAT ISLANDS OF DOWNTOWN BOSTON/PROVIDENCE...WITH LOW TEMPS BOTTOMING OUT IN THE LOWER 60S. A TOUCH OF PATCHY GROUND FOG POSSIBLE LATE IN THE TYPICALLY PRONE LOCATIONS...BUT NOTHING WIDESPREAD IS ANTICIPATED.
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&& .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM THURSDAY/... ANOMALOUS MID LEVEL TROUGH REMAINS ANCHORED ACROSS EASTERN CANADA...JUST NORTH OF THE GREAT LAKES. THIS WILL RESULT IN ANOTHER DAY WITH BELOW NORMAL TEMPERATURES. A MIXTURE OF CLOUDS AND SUNSHINE ANTICIPATED AS A MOISTURE-STARVED SHORTWAVE MOVES ACROSS SOUTHERN NEW ENGLAND. MAINLY DRY WEATHER EXPECTED...BUT THE SHORTWAVE COULD RESULT IN A PASSING SPRINKLE OR TWO. WE WILL HAVE TO WATCH A WEAK WAVE OF LOW PRESSURE PASSING EAST OF THE 40N/70W BENCHMARK...BUT AT THIS TIME APPEARS IT SHOULD BE FAR ENOUGH AWAY TO SPARE EVEN THE CAPE/ISLANDS ANY MEASURABLE RAINFALL. THIS ANOMALOUS MID LEVEL LONGWAVE TROUGH NUDGES SLIGHTLY CLOSER TO OUR REGION WEDNESDAY NIGHT. A MODEST SHORTWAVE MOVING THROUGH THIS LONGWAVE TROUGH COULD ARRIVE SOON ENOUGH TO GIVE US A PASSING SHOWER LATE WEDNESDAY NIGHT...ESPECIALLY ALONG AND WEST OF THE CT RIVER VALLEY. && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... HIGHLIGHTS... * A FEW SHOWERS POSSIBLE ON THURSDAY AND FRIDAY * LOW PRES COULD BRING RAIN SATURDAY AND SUNDAY THE HIGH AMPLITUDE UPPER LEVEL TROUGH ACROSS THE EASTERN U.S. CONTINUES TO BE THE DOMINANT FEATURE THROUGH THE FIRST PART OF THE LONG TERM. AT THE SURFACE...DURING THURSDAY AND FRIDAY SOUTHERN NEW ENGLAND IS IN BETWEEN A HIGH PRESSURE CENTERED WELL OFFSHORE...AND A LOW PRESSURE SYSTEM CENTERED NORTH OF THE GREAT LAKES REGION. RETURN FLOW ON THE WEST SIDE OF THE HIGH WILL BRING SOME INCREASE IN MOISTURE TO OUR AREA FOR THURSDAY AND FRIDAY...SUFFICIENT TO WARRANT A CHANCE FOR MAINLY DIURNAL SHOWERS. ON THURSDAY THERE WILL ALSO BE A SHORTWAVE ROTATING AROUND THE TROUGH WHICH WOULD ALSO CONTRIBUTE TO THE CHANCE FOR SHOWERS. FORECAST MODEL SOUNDINGS FOR THURSDAY INDICATE MINIMAL CAPE...SO THUNDER NOT ANTICIPATED AT THIS TIME. FRIDAY CAPE OVER THE INTERIOR MAY INCREASE TO A FEW HUNDRED J/KG...SOME ISOLATED THUNDER MAY OCCUR. DAYTIME HIGHS MAINLY IN THE UPPER 70S TO LOW 80S ARE EXPECTED...BUT OVER THE COURSE OF THU AND FRI SURFACE DEWPOINTS WILL CLIMB INTO THE 60S...BRINGING A SLIGHTLY MORE MUGGY FEEL. DURING THIS WEEKEND THE UPPER TROUGH SHIFTS SOMEWHAT TO THE WEST...ENABLING A FRONT TO APPROACH THE REGION FROM THE SOUTHEAST. IN ADDITION A WAVE OF LOW PRESSURE MAY MOVE ALONG THE FRONT. THIS WILL BRING THE POTENTIAL FOR STEADY RAIN TO AT LEAST A PORTION OF THE REGION. THERE CONTINUE TO BE SOME RUN TO RUN MODEL DISCREPANCIES REGARDING HOW CLOSE THE FRONT COMES TO OUR AREA...AND HOW LONG IT LINGERS NEARBY. THE CLOSER THE FRONT COMES TO THE AREA...THE MORE WIDESPREAD THE RAIN. THE 12Z GFS AND ECMWF HAVE SOME DIFFERENCES IN PRECIP TIMING...BUT BOTH SHOW THE POTENTIAL FOR PERIODS OF RAIN SATURDAY AND/OR SUNDAY. WILL GO WITH CHANCE POPS FOR MOST OF THIS TIMEFRAME. 12Z GFS SHOWS ROBUST MOISTURE WITH A RIBBON OF UP TO 2 INCH PWATS LINGERING IN OUR AREA. IF THIS SCENARIO DOES COME TO FRUITION THERE COULD BE SOME LOCALLY HEAVY RAINFALL DURING THE WEEKEND. CONSIDERABLE MODEL SPREAD ON CONDITIONS FOR MONDAY...ECMWF INDICATES FRONT MAY BE OFFSHORE AT THIS POINT...WILL GO WITH ONLY A LOW CHANCE POP. DRIER CONDITIONS MAY PREVAIL FOR TUESDAY...AS BY THIS TIME THE FRONT SHOULD BE FURTHER OFFSHORE. && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
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FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM...TODAY THROUGH THURSDAY... TODAY...HIGH CONFIDENCE. VFR CONDITIONS DESPITE SCATTERED TO BROKEN DECK OF MID LEVEL CLOUDINESS. SEAS BREEZES DEVELOP THIS AFTERNOON ALONG PORTIONS OF THE IMMEDIATE COAST. TONIGHT AND THURSDAY...HIGH CONFIDENCE. MAINLY VFR CONDITIONS. A FEW HIT AND MISS SHOWERS/THUNDERSTORMS ARE EXPECTED DURING THE DAY THURSDAY ACROSS THE INTERIOR...WHICH MAY RESULT IN BRIEFLY LOWER CIGS/VSBYS. KBOS TAF...HIGH CONFIDENCE IN TAF. SEA BREEZES ARE EXPECTED TO DEVELOP BY EARLY AFTERNOON. KBDL TAF...HIGH CONFIDENCE IN TAF. OUTLOOK...THURSDAY NIGHT THROUGH SUNDAY... THURSDAY NIGHT AND FRIDAY...HIGH CONFIDENCE. MAINLY VFR. LOW PROBABILITY OF A BRIEF PERIOD OF MVFR CONDITIONS IN -SHRA. DURING FRI ISOLATED THUNDER POSSIBLE IN THE AFTERNOON/EVENING...MAINLY OVER THE INTERIOR. SATURDAY AND SUNDAY...LOW CONFIDENCE. MAINLY VFR NW...CHANCE FOR MVFR CIGS/VSBYS IN SCATTERED SHOWERS. MVFR CONDITIONS MORE PROBABLE TOWARDS EASTERN MA/RI IN -SHRA.
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&& .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT... HIGH CONFIDENCE. AS OF EARLY THIS EVENING LEFTOVER SWELL HAS DIMINISHED OVER THE SOUTHERN OUTER COASTAL WATERS...AND SEAS ARE EXPECTED TO REMAIN BELOW SCA THRESHOLDS OVERNIGHT. OTHERWISE...WINDS/SEAS SHOULD REMAIN BELOW SMALL CRAFT ADVISORY LEVELS THROUGH WEDNESDAY. SEAS MAY BUILD TO 5 FEET ACROSS THE OUTER COASTAL WATERS LATE WEDNESDAY NIGHT AS AN OFFSHORE LOW PRESSURE MOVES BY. OUTLOOK...THURSDAY THROUGH SUNDAY... THURSDAY AND FRIDAY...HIGH CONFIDENCE. LINGERING ROUGH SEAS ON THE OUTER WATERS ON THURSDAY FROM AN OFFSHORE LOW SHOULD SUBSIDE DURING THE DAY...WITH HIGH PRESSURE OVER THE WATERS. WINDS BELOW SCA THRESHOLDS THROUGH THE PERIOD. SATURDAY AND SUNDAY...LOW CONFIDENCE. MORE UNSETTLED WEATHER POSSIBLE WITH AN APPROACHING FRONT AND POSSIBLE WAVE OF LOW PRESSURE. THERE IS A CHANCE OF SCA SEAS/WINDS DEVELOPING DURING THIS TIMEFRAME. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...NONE. && $$ SYNOPSIS...BELK NEAR TERM...FRANK SHORT TERM...BELK LONG TERM...NMB AVIATION...FRANK/NMB MARINE...BELK/NMB

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