Area Forecast Discussion
Issued by NWS Boston, MA

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000 FXUS61 KBOX 181753 AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 153 PM EDT FRI APR 18 2014 .SYNOPSIS... EAST TO NORTHEAST FLOW WILL KEEP CLOUDY SKIES IN THE EAST ALONG WITH COOL TEMPERATURES...WHILE WESTERN AREAS HAVE MIX OF CLOUDS AND AFTERNOON SUN. A WEAKENING FRONT WILL PUSH ACROSS THE REGION ON SATURDAY. HIGH PRESSURE WILL RESULT IN DRY AND PLEASANT WEATHER SUNDAY AND MONDAY. LOW PRESSURE WILL LIKELY BRING A PERIOD OF WET WEATHER TO THE REGION SOMETIME LATE TUESDAY INTO WEDNESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... MARINE CLOUDS SPREAD ACROSS MUCH OF SOUTHERN NEW ENGLAND DURING THE MORNING. EAST WINDS ARE EXPECTED TO CONTINUE IN THE EAST...BUT WESTERN AREAS MAY SEE THIS WIND SHIFT TO SOUTH LATER THIS AFTERNOON. OVERNIGHT MODEL RH FIELDS SHOW A GOOD SUPPLY OF MOISTURE BELOW 925 MB THROUGH THE AFTERNOON IN EASTERN MASS...BUT ALSO SOME THINNING OF THIS MOIST LAYER IN THE CT VALLEY. SO THE EXPECTATION IS THAT WESTERN AREAS WILL SEE THE CLOUDS THIN OUT AT LEAST PARTIALLY DURING THIS AFTERNOON WHILE WORCESTER AND EAST WILL REMAIN MAINLY UNDER THE CLOUDS. THE ONSHORE FLOW OFF THE 39-40F WATER IN MASSACHUSETTS BAY SHOULD KEEP TEMPS IN THE EAST WELL BELOW NORMAL IN THE 40S /NORMAL 56-61/ WHILE WESTERN AREAS SUCH AS THE CT VALLEY WILL BENEFIT FROM THE LIMITED AFTERNOON SUN AND REACH THE LOW TO MID 50S. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/... TONIGHT... SFC COLD FRONT WILL BE RAPIDLY SLIDING ACROSS THE AREA DURING THE OVERNIGHT HOURS. HOWEVER...SOUNDINGS SHOW MOISTURE LAYER REMAINS MAINLY ABOVE H6...WITH DWPT DEPRESSIONS EXCEEDING 10C FROM THE SFC TO H6. LOW-MID LVL F-GEN IS ALSO VERY WEAK AS IT ARRIVES GIVEN IT IS TRYING TO PUSH THROUGH RIDGING. THEREFORE...EXPECT LITTLE FANFARE WITH THIS FRONTAL PASSAGE EXCEPT MID-HIGH CLOUDINESS AND W WINDS INCREASING THROUGH SUNRISE. CONTINUE TO SUGGEST NIL POPS. BKN-OVC CLOUDS WILL KEEP MINS WARMER THAN PREVIOUS NIGHTS...BUT ANOMALOUSLY COOL AIRMASS SUGGESTS TEMPS STILL DROP TO THE LOW-MID 30S. SAT... HIGH PRES REGAINS CONTROL WITH COLD ADVECTION TO START THE DAY. THIS COLD ADVECTION WILL ALLOW MIXING UNDER ONLY PARTLY CLOUDY SKIES TO REACH HIGHER THAN H8...WHERE TEMPS ONLY DIP TO AROUND -1C. COMBINE THIS WITH W DOWNSLOPE FLOW...AND TEMPS SHOULD BE ABLE TO REBOUND INTO THE LOW 60S. LOW CHANCE OF A SEA BREEZE GIVEN H92 WINDS REACH AROUND 20-25 KT. THEREFORE...ALSO EXPECT WINDS AROUND 20 MPH THROUGH THE DAY. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... HIGHLIGHTS... * DRY SUNDAY AND MONDAY WITH CHILLY NIGHTS/MILD DAYS * WET WEATHER LIKELY SOMETIME LATE TUESDAY INTO WEDNESDAY DETAILS... SATURDAY NIGHT AND SUNDAY... HIGH PRESSURE OVERHEAD WILL RESULT IN DRY WEATHER WITH A CHILLY SATURDAY NIGHT BEING REPLACED BY A MILD SUNDAY AFTERNOON. LIGHT WINDS/MAINLY CLEAR SKIES WILL ALLOW FOR EXCELLENT RADIATIONAL COOLING CONDITIONS SAT NIGHT. LOW TEMPS SHOULD BOTTOM OUT IN THE MID TO UPPER 20S ACROSS THE NORMALLY COLDER OUTLYING LOCATIONS OF SOUTHWEST NH/NORTHWEST MA...TO MAINLY THE 30S ELSEWHERE. ON SUNDAY...PLENTY OF SUNSHINE WILL ALLOW FOR HIGHS TO REACH INTO THE UPPER 50S AND LOWER 60S JUST INLAND FROM THE COAST. HOWEVER...WEAK PRESSURE GRADIENT WILL ALLOW FOR SEA BREEZES ON THE IMMEDIATE COAST PROBABLY HOLDING HIGHS IN THE UPPER 40S TO LOWER 50S. SUNDAY NIGHT... HIGH PRESSURE WILL REMAIN ANCHORED OVER THE REGION ALLOWING FOR ANOTHER GOOD NIGHT OF RADIATIONAL COOLING. LOW TEMPS WILL BE MAINLY IN THE 30S. MONDAY... HIGH PRESSURE WILL STILL BE IN CONTROL OF OUR WEATHER WITH A MIXTURE OF SUN AND CLOUDS. 850 MB TEMPS MODERATE CONSIDERABLY FROM SUNDAY/S VALUES REACHING BETWEEN +6C TO +8C. THIS SHOULD ALLOW HIGH TEMPS TO REACH WELL INTO THE 60S ACROSS MUCH OF THE REGION...TO PERHAPS EVEN NEAR 70 IN A FEW LOCALES. ALONG THE IMMEDIATE COAST INCLUDING BOSTON...ITS UNCERTAIN IF SEA BREEZES WILL DEVELOP IN THIS TIME RANGE. IF SEA BREEZES ARE ABLE TO DEVELOP...IT WOULD PROBABLY KEEP HIGH TEMPS IN THE 50S...BUT THEY MAY END UP VERY LOCALIZED JUST AFFECTING AREAS WITHIN A FEW MILES OF THE COAST. TUESDAY AND WEDNESDAY... A POTENTIALLY STRONG UPPER LEVEL SHORTWAVE WILL DIVE SOUTHEASTWARD FROM CANADA. THIS WILL SPAWN A SURFACE LOW PRESSURE SYSTEM APPROACHING OUR REGION FROM THE WEST. AT THIS TIME RANGE...THERE IS LOW CONFIDENCE ON STRENGTH/TIMING OF SHORTWAVE AND TRACK/INTENSITY OF SURFACE LOW PRESSURE. IT DOES LOOK LIKE A DECENT SHOT FOR AT LEAST PERIOD OF WET WEATHER SOMETIME LATE TUESDAY INTO WEDNESDAY. THURSDAY... DRY WEATHER SHOULD FOLLOW BEHIND THE DEPARTING LOW PRESSURE SYSTEM. SOME INDICATIONS ARE THAT IT MAY BE WINDY BEHIND THE SYSTEM WITH NEAR OR BELOW NORMAL TEMPERATURES. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
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LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. MODERATE CONFIDENCE TONIGHT...HIGHER CONFIDENCE SATURDAY AND SATURDAY NIGHT... THROUGH 00Z...BROAD AREA OF 2500 FOOT CIGS SPREAD ACROSS MOST OF SOUTHERN NEW ENGLAND DURING THE MORNING. BUT BY AFTERNOON IT HAD BROKEN INTO TWO SMALLER AREAS...ONE ALONG THE COASTAL PLAIN AND THE OTHER OVER THE CENTRAL HILLS /CENTRAL MASS AND S CENTRAL NH/. LARGE AREA OF CIRRUS OVERLAYS THESE LOWER CLOUDS. EXPECT THE COASTAL PLAIN LOWER CLOUDS TO LINGER THROUGH THE EVENING...FED BY MOIST AIR OFF MASS BAY. TONIGHT...HIGH CONFIDENCE IN TREND...MODERATE CONFIDENCE IN TIMING. EXPECT WINDS TO SHIFT AS A COLD FRONT FROM THE GREAT LAKES APPROACHES. THIS WILL START MOVING THE LOWER CLOUDS OUT OF THE AREA WHILE VFR CLOUDS ASSOCIATED WITH THE FRONT MOVE IN. MOVEMENT OF THE FRONT WOULD BRING IT THROUGH OUR AREA BETWEEN 06Z AND 12Z. CONDITIONS SHOULD REMAIN VFR THROUGH THE NIGHT WITH WINDS SHIFTING TO NORTHWEST LATE. SATURDAY AND SATURDAY NIGHT... DRIER AIR MOVES IN. EXPECT CLEARING SKIES AND VFR. DAYTIME HEATING BY THE SUN WILL DRAW STRONGER WINDS GUSTS TO THE SURFACE WITH GUSTS TO AT LEAST 25 KNOTS...POSSIBLY 30 KNOTS. THESE WINDS WILL DIMINISH AROUND SUNSET. CONTINUED VFR WITH DIMINISHING NORTH WIND SATURDAY NIGHT. KBOS TERMINAL...MODERATE CONFIDENCE. MAIN ISSUE IS EXTENT AND DURATION OF MVFR CIGS THROUGH EARLY TONIGHT. KBDL TERMINAL...HIGH CONFIDENCE. SATURDAY NIGHT THROUGH MONDAY...HIGH CONFIDENCE IN VFR CONDITIONS. TUESDAY...LOW TO MODERATE CONFIDENCE. VFR CONDITIONS MAY DETERIORATE TO MVFR-IFR THRESHOLDS LATE TUE OR TUE NIGHT IN RAIN SHOWERS.
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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 /THROUGH SATURDAY/...HIGH CONFIDENCE. ALTHOUGH WINDS EACH DAY ARE EXPECTED TO REMAIN BELOW THE 25 KT THRESHOLD FOR SMALL CRAFT ADVISORY...A LINGERING SWELL WILL KEEP SEAS AT LEAST 5-7FT THROUGH THE DAY ON SAT ON THE OCEAN WATERS ESPECIALLY. THEREFORE WILL CONTINUE SMALL CRAFT FOR HAZARDOUS SEAS ACROSS THE WATERS INTO 12Z SAT AT LEAST...WITH NEAR SHORE WATERS DROPPING EARLIER. WINDS TODAY BEING OUT OF THE NE...SHIFTING TO THE SW TONIGHT THEN W DURING THE DAY ON SAT. OUTLOOK...SATURDAY NIGHT THROUGH TUESDAY... SATURDAY NIGHT AND SUNDAY...MODERATE TO HIGH CONFIDENCE. HIGH PRESSURE OVER NORTHERN NEW ENGLAND AND LOW PRESSURE WELL TO THE SOUTH OF THE WATERS WILL RESULT IN NORTH TO NORTHEAST WINDS. WIND GUSTS OF 20 TO 25 KNOTS ALONG WITH 3 TO 5 FOOT SEAS ARE POSSIBLE ACROSS THE OUTER-WATERS. THIS MAY RESULT IN MARGINAL SCA CONDITIONS. MONDAY AND TUESDAY...MODERATE TO HIGH CONFIDENCE. WEAK PRESSURE GRADIENT SHOULD KEEP WINDS/SEAS GENERALLY BELOW SCA THRESHOLDS. WE MAY SEE MARGINAL SCA SEAS DEVELOP LATE TUE/TUE NIGHT AS A RESULT OF SOUTHEAST SWELL FROM LOW PRESSURE WELL EAST OF THE WATERS. && .FIRE WEATHER... SATURDAY IS THE THREE DAY MARK SINCE LAST APPRECIABLE RAINFALL ACROSS SOUTHERN NEW ENGLAND. GIVEN THIS FACT...WITH TEMPERATURES RISING INTO THE LOW 60S AND LOW DWPTS IN THE 20S...MIN RH VALUES SHOULD DIP TO AROUND 30 PERCENT IN THE AFTERNOON. THIS WILL COMBINE WITH W WIND GUSTS OF 20 TO 25 MPH...WITH OCCASIONAL GUSTS TO 30 MPH. CONFIDENCE IS HIGH THAT THESE CONDITIONS WILL BE REALIZED. && .HYDROLOGY...
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MINOR FLOODING CONTINUES ALONG PORTIONS OF THE MAIN STEM CT RIVER. MOST POINTS HAVE CRESTED AND ARE NOW RECEDING...MIDDLE HADDAM WILL CREST TONIGHT. SEE THE LATEST FLOOD STATEMENT FOR DETAILS. FLOOD WARNINGS REMAIN POSTED ALONG CT RIVER AT... NORTHAMPTON THOMPSONVILLE HARTFORD MIDDLE HADDAM
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&& .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 2 PM EDT THIS AFTERNOON FOR ANZ232. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 5 PM EDT THIS AFTERNOON FOR ANZ235-237. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 8 AM EDT SATURDAY FOR ANZ250-251-254>256. && $$ SYNOPSIS...FRANK/DOODY NEAR TERM...WTB SHORT TERM...DOODY LONG TERM...FRANK AVIATION...WTB/FRANK MARINE...WTB/FRANK/DOODY FIRE WEATHER... HYDROLOGY...

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