Area Forecast Discussion
Issued by NWS Boston, MA

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000 FXUS61 KBOX 242023 AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 423 PM EDT SUN APR 24 2016 .SYNOPSIS...
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HIGH PRESSURE WILL PASS ACROSS THE REGION TONIGHT KEEPING CONDITIONS DRY AND COOL. A FRONT WILL STALL ACROSS THE REGION MONDAY...THEN SLOWLY PUSH SOUTH TUESDAY. LOW PRESSURE WAVE TRAVELS ALONG THE STALLED COLD FRONT...BRINGING MUCH NEEDED RAINFALL. HIGH PRESSURE BUILDS OVER THE REGION WEDNESDAY. ANOTHER LOW PRESSURE AREA RACES EAST FROM THE PLAINS AND PASSES SOUTH OF NEW ENGLAND FRIDAY. CANADIAN HIGH PRESSURE BRINGS DRY WEATHER FOR THE WEEKEND.
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&& .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... 4 PM UPDATE... SEA BREEZE CONTINUES TO DOMINATE ACROSS THE MASS EAST COAST THIS AFTERNOON KEEPING TEMPS IN THE UPPER 40S TO LOW 50S. ELSEWHERE...TEMPS HAVE RISEN INTO THE LOW 60S ACROSS THE INTERIOR. CLEAR SKIES AND MAINLY LIGHT WINDS HAS RESULTED IN A SPRING DAY IN SOUTHERN NEW ENGLAND. TONIGHT... HIGH PRESSURE OVERHEAD WILL ALLOW FOR LIGHT WINDS AND MOSTLY CLEAR SKIES. ANTICIPATE SURFACE TEMPS TO DROP INTO THE LOW TO MID 30S ESPECIALLY ACROSS AREAS WHERE THE GROWING SEASON HAS BEGUN. THE ONLY ISSUE IS THE HIGH LEVEL CLOUDS ROLLING IN FROM THE EASTERN GREAT LAKES. BELIEVE THE CLOUDS WILL LIMIT RADIATIONAL POTENTIAL ACROSS WESTERN MASS AND CT WHERE AS SOUTHEASTERN MASS COULD TRULY RADIATE OUT ENOUGH FOR FROST DEVELOPMENT. THEREFOR ISSUED A FROST ADV FOR SE MASS FOR TONIGHT. IF CLOUDS HOLD UP HOWEVER THEN FROST ADV MAY NEED TO BE EXPANDED. OTHERWISE ANTICIPATE A DRY FORECAST OVERNIGHT. && .SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/... TOMORROW INTO TOMORROW NIGHT... HIGH PRESSURE WILL MOVE OFFSHORE TOMORROW AS A STATIONARY FRONT BEGINS TO PUSH INTO THE REGION. CLOUDS WILL INCREASE THROUGHOUT THE DAY. OVERALL EXPECT DRY WEATHER TO START...WITH SOME SHOWERS MOVING ACROSS NORTHERN MASS LATE TOMORROW AFTERNOON THANKS TO WEAK ISENTROPIC LIFT AND WAA. TEMPERATURES ACROSS THE REGION WILL WARM INTO THE MID 60S WITH THE POTENTIAL FOR A WEAK SEA BREEZE ACROSS THE MASS EAST COAST. UPPER LEVEL SHORTWAVE WILL PUSH THROUGH THE ZONAL FLOW AND MOVE ALONG THE STATIONARY FRONT. GUIDANCE IS STRUGGLING ON EXACT LOCATION OF THE FRONT AND THUS BOTH TEMPERATURES AND WIND FORECASTS HAVE BEEN A STRUGGLE. RIGHT NOW BELIEVE THE FRONT OVER WILL PUSH THROUGH SOUTHERN NEW ENGLAND RESULTING IN SHOWERY WEATHER OVERNIGHT. ADDED THE POTENTIAL FOR THUNDER ACROSS SOUTHERN ZONES AND THE SOUTHERN WATERS AS MODELS SHOW ELEVATED INSTABILITY. TEMPS WILL REMAIN MILD THROUGH THE FIRST HALF OF THE NIGHT BEFORE DROPPING INTO THE 40S TOWARDS DAY BREAK AS THE FRONT PASSES THROUGH. && .LONG TERM /TUESDAY THROUGH SUNDAY/...
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BIG PICTURE... CLOSED LOW LINGERS OVER LABRADOR THROUGH THE WEEKEND. THIS MAINTAINS A WEST TO NORTHWEST CYCLONIC FLOW OVER NEW ENGLAND. A SECOND LONGWAVE TROUGH HOLDS OVER THE SOUTHWEST USA WITH MULTIPLE SHORTWAVES MOVING THROUGH THIS POSITION AND THEN EJECTING THROUGH THE GREAT LAKES AND NORTHEAST. MODEL MASS FIELDS REMAIN IN GOOD AGREEMENT THROUGH FRIDAY AND THEN DIVERGE. ALL SHOW SIMILAR TIMING ON THE TWO UPPER SHORTWAVES. THE DAILIES... TUESDAY... SHORTWAVE MOVING AROUND THE LABRADOR UPPER LOW WILL ENERATE AT LEAST ONE WAVE ON THE COLD FRONT SOUTH OF NEW ENGLAND. THIS WILL MAINTAIN RAIN/SHOWERS ACROSS SOUTHERN NEW ENGLAND MUCH OF THE DAY...TAPERING LATE. PRECIPITABLE WATER VALUES WILL BE OVER AN INCH...ENOUGH TO PROVIDE A GOOD WETTING WITH AREAL VALUES FORECAST AT 0.50 TO 0.75 INCHES. WIND WILL ALSO BECOME A FACTOR. THE APPROACHING SURFACE LOW WILL GENERATE A STRONG LOW LEVEL NORTHEAST WIND JUST BEHIND THE FRONT. THIS WILL MOSTLY AFFECT EAST COASTAL MASS WITH GUSTS 20-25 KNOTS POSSIBLE. SHOWERS TAPER OFF DURING THE FIRST PART OF TUESDAY NIGHT. HIGH PRESSURE BUILDS IN FROM THE NORTHWEST WITH CLEARING SKIES WITH A COLDER DRIER AIRMASS. WEDNESDAY... HIGH PRESSURE AND DRY WEATHER. MIXING SHOULD REACH TO 850 MB WHERE TEMPS OF -1C TO -3C WILL SUPPORT MAX TEMPS IN THE 50S...NEAR 60 IN SPOTS. RADIATIONAL COOLING WEDNESDAY NIGHT AND DEW POINTS IN THE 20S WILL ALLOW MIN TEMPS IN THE UPPER 20S TO MID 30S AND POSSIBLY A LITTLE LOWER. THURSDAY-FRIDAY... ANOTHER SHORTWAVE APPROACHES FROM THE MIDWEST AND GENERATES SURFACE LOW PRESSURE WHICH PASSES SOUTH OF NEW ENGLAND. GFS AND ECMWF BRING MEASUREABLE PCPN INTO THE REGION LATE THURSDAY AFTERNOON CONTINUE THROUGH FRIDAY MORNING. THE BULK OF FORCING AND QPF REMAIN SOUTH OF NEW ENGLAND SO AMOUNTS SHOULD REMAIN LIGHT. WE HAVE STAYED WITH LOW- END CHANCE POPS. SATURDAY-SUNDAY... HIGH PRESSURE BUILDS SOUTH FROM CANADA WITH DRY WEATHER. ANOTHER SHORTWAVE EJECTS FROM THE SOUTHWEST USA DURING THIS PERIOD. HERE THE MODELS DIVERGE WITH THE ECMWF BRINGING RAIN INTO SOUTHERN NEW ENGLAND SUNDAY MORNING WHILE THE GFS REMAINS DRY. WE HAVE USED A COMPROMISE IN TIMING...BUT ONE THAT KEEPS RAIN OUT OF OUR AREA UNTIL AFTER THE FORECAST PERIOD.
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&& .AVIATION /20Z SUNDAY THROUGH FRIDAY/...
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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 MONDAY NIGHT/...HIGH CONFIDENCE. TONIGHT...HIGH CONFIDENCE. VFR CONDITIONS. HIGH CLOUDS WILL BEGIN TO INCREASE AFTER 03Z FROM WEST TO EAST. MONDAY...MODERATE TO HIGH CONFIDENCE. VFR CONDITIONS. SEA BREEZE DEVELOPMENT IS POSSIBLE IN THE AFTERNOON FOR MASS EAST COASTLINE. SOME SHOWERY WEATHER WILL MOVE IN NORTH OF THE PIKE DURING THE AFTERNOON. MONDAY NIGHT...MODERATE CONFIDENCE. VFR TO MVFR CONDITIONS OVERNIGHT AS SHOWERS CONTINUE TO SPREAD AND INCREASE ACROSS THE REGION. KBOS TAF...HIGH CONFIDENCE. SEA BREEZE WILL DISSIPATE BY SUNSET. LOW PROB IN SEA BREEZE DEVELOPMENT TOMORROW. KBDL TAF...HIGH CONFIDENCE. LOW PROBABILITY OF MVFR CIGS/VSBYS IN -SHRA LATE MON AFTERNOON. OUTLOOK /TUESDAY THROUGH FRIDAY/...MODERATE CONFIDENCE. TUESDAY...MODERATE TO HIGH CONFIDENCE. MVFR CIGS/VSBYS WITH AREAS OF IFR ESPECIALLY OVER THE COASTAL PLAIN AND ISLANDS. NORTHEAST WINDS GUST 20 TO 25 KNOTS ALONG THE MASSACHUSETTS EAST COAST AND ISLANDS. WEDNESDAY...HIGH CONFIDENCE. VFR. THURSDAY-FRIDAY...MODERATE CONFIDENCE. VFR WITH AREAS OF MVFR/IFR CIGS/VSBYS POSSIBLE THURSDAY NIGHT.
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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 MONDAY NIGHT/...HIGH CONFIDENCE. HIGH PRESSURE OVERHEAD HAS ALLOWED FOR GUSTS BELOW 20 KTS AND SEAS TO CONTINUE TO RELAX TONIGHT. STALLED FRONT OVER NEW ENGLAND TOMORROW WILL ALLOW FOR AN INCREASE SW WIND GRADIENT. SW GUSTS COULD INCREASE TO 20-25 KTS TOMORROW BEFORE THE FRONT MOVES THROUGH TOMORROW NIGHT. OUTLOOK /TUESDAY THROUGH FRIDAY/...MODERATE CONFIDENCE. TUESDAY... NORTHEAST WINDS WITH GUSTS 20 TO 25 KNOTS ALONG THE WATERS EAST OF MASSACHUSETTS. THE HIGHEST SEAS WILL BE ON THE SOUTHERN OUTER WATERS AND RI SOUND WHERE HEIGHTS SHOULD REACH 5-6 FEET. A SMALL CRAFT ADVISORY MAY BE NEEDED. WEDNESDAY... NORTHWEST WINDS GUSTING 20 KNOTS EAST OF CAPE ANN. LINGERING 5 FOOT SEAS IN THE MORNING ON THE SOUTHERN OUTER WATERS. THURSDAY-FRIDAY... NORTHWEST WINDS SHIFT TO SOUTH WINDS THURSDAY AND EAST WINDS FRIDAY...LESS THAN 20 KNOTS. SEAS LESS THAN 4 FEET. DECREASING VSBYS IN DEVELOPING RAIN ESPECIALLY SOUTH OF NEW ENGLAND.
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&& .FIRE WEATHER...
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MONDAY...ANTICIPATE MAINLY DRY WEATHER CONDITIONS AS CLOUDS CONTINUE TO THICKEN ACROSS THE REGION. MIN RH VALUES WILL DROP DOWN CLOSE TO 30 PERCENT AS SW WINDS GUSTS WILL INCREASE BETWEEN 10-15 MPH. LOCATIONS ALONG THE CAPE MAY SEE GUSTS NEAR 30 MPH. A FEW SHOWERS ARE POSSIBLE IN THE AFTERNOON NORTH OF THE PIKE. TUESDAY...A SLOW MOVING COLD FRONT WILL BRING ABOUT ONE-HALF TO THREE-QUARTERS OF AN INCH OF RAIN TO THE REGION. WEDNESDAY... HIGH PRESSURE AND DRY AIR FROM CANADA WILL BRING MINIMUM RH VALUES OF 20 TO 30 PERCENT AWAY FROM THE COAST...AND 35 TO 50 PERCENT IN COASTAL AREAS. LIGHT NORTHWEST WINDS UNDER 15 MPH.
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&& .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...FROST ADVISORY FROM 11 PM THIS EVENING TO 8 AM EDT MONDAY FOR MAZ017>021. RI...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR ANZ250- 254. && $$ SYNOPSIS...WTB/DUNTEN NEAR TERM...DUNTEN SHORT TERM...DUNTEN LONG TERM...WTB AVIATION...WTB/DUNTEN MARINE...WTB/DUNTEN FIRE WEATHER...

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