Area Forecast Discussion
Issued by NWS Boston, MA

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000 FXUS61 KBOX 250609 AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 209 AM EDT SAT OCT 25 2014 .SYNOPSIS...
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A WEAK RIDGE OF HIGH PRESSURE MOVES ACROSS THE REGION TODAY PROVIDING SUNSHINE AND MILD WEATHER. A COLD FRONT WILL SWEEP ACROSS THE REGION TONIGHT AND MAY BE ACCOMPANIED BY A FEW SHOWERS...THEN DRY AND BLUSTERY WEATHER FOLLOWS SUNDAY WITH WARMING EARLY NEXT WEEK. A COLD FRONT MAY BRING SHOWERS TUESDAY NIGHT INTO WEDNESDAY. HIGH PRESSURE BRIEFLY VISITS ON THURSDAY WITH THE POTENTIAL FOR A LOW PRESSURE SYSTEM IN OUR VICINITY AT THE END OF THE NEXT WORKWEEK.
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&& .NEAR TERM /UNTIL 6 AM THIS MORNING/...
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2 AM UPDATE... BACK EDGE OF THE CLOUD SHIELD NOW INTO CENTRAL-EASTERN MA INTO RI...AND CONTINUING TO MAKE STEADY EASTWARD PROGRESS. PREVIOUS FORECAST HANDLING THIS TIMING WELL SO NO MAJOR CHANGE WITH THIS UPDATE. EARLIER DISCUSSION BELOW. ------------------------------------------------------------------ BACK EDGE OF CLOUD LINE MOVING ACROSS THE CT RVR VLY AND ADVANCING STEADILY EASTWARD. CLOUDS WILL CONTINUE TO ERODE AS MID LEVEL FLOW TRANSITIONS FROM CYCLONIC TO ANTICYCLONIC IN RESPONSE TO WEAK SHORT WAVE RIDGING APPROACHING FROM NY AND PA. SEASONABLY COOL NIGHT AHEAD WITH TEMPS FALLING INTO THE 40S...UPPER 30S WELL INLAND. A MODEST NW WIND AT 5 TO 15 MPH WITH GUSTS UP TO 20 MPH HIGHER TERRAIN AND ALONG THE COAST WILL MAKE IT FEEL A BIT COOLER. PREVIOUS FORECAST CAPTURES THESE DETAILS NICELY SO ONLY CHANGE WITH THIS FORECAST UPDATE WAS TO MODIFY HOURLY GRIDS TO BETTER REFLECT CURRENT TRENDS PER SATELLITE IMAGERY AND SURFACE OBS.
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&& .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SUNDAY/... SATURDAY... FAIRLY POTENT MID LEVEL SHORTWAVE AND ASSOCD COLD FRONT WILL BE MOVING EAST FROM THE UPPER LAKES. WEAK SHORTWAVE RIDGING AHEAD OF THE TROF WILL PROVIDE ENOUGH SUBSIDENCE IN SNE FOR MOSUNNY SKIES FOR MUCH OF THE DAY ALONG WITH A MODEST WESTERLY BREEZE. SOUNDINGS SHOW MIXING UP TO 925 MB. TEMPS AT THIS LEVEL ARE NEAR 10C WHICH TRANSLATES TO MAXES 60-65 DEGREES...COOLER HIGHER TERRAIN. SATURDAY NIGHT... MID LEVEL SHORTWAVE MOVES ACROSS SNE WITH COLD FRONT MOVING INTO W ZONES 00-02Z AND OFF THE COAST AROUND 06Z. MOISTURE AND LOW LEVEL CONVERGENCE ARE LIMITED BUT SHORTWAVE IS FAIRLY ROBUST AND THERE IS ENOUGH QG FORCING TO SUPPORT A FEW SHOWERS. WE HAVE 20-30 POPS IN THE GRIDS. BEGIN THE FRONT...W/NW WINDS WILL BECOME GUSTY OVERNIGHT. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... * MAINLY DRY AND SLIGHTLY COOLER THAN NORMAL ON SUNDAY * HIGH PRESSURE PREVAILS ON MONDAY * CHANCE FOR SHOWERS TUE NIGHT/WED WITH A COLD FRONTAL PASSAGE * POTENTIAL FOR LOW PRESSURE SYSTEM IN OUR VICINITY AT THE END OF NEXT WEEK DETAILS... SUN...AT THE SURFACE A LOW PRESSURE SYSTEM WILL CROSS THROUGH THE CANADIAN MARITIMES DURING THE DAY...WITH ITS ASSOCIATED COLD FRONT PULLING FURTHER OFFSHORE FROM SOUTHERN NEW ENGLAND. FAIRLY TIGHT PRESSURE GRADIENT OVER OUR AREA WITH SOME COLD AIR ADVECTION AND H850 WINDS 30 TO 40 KT...SO WILL LIKELY HAVE A BLUSTERY NW WIND ON SUN WITH GUSTS 20 TO 30 MPH AT TIMES POSSIBLE. ALOFT...MODELS CONTINUE TO SHOW ROBUST SHORT WAVE DIGGING INTO UPPER TROUGH AND MOVING THROUGH OUR AREA. THIS WILL MAINLY BRING CLOUDS TO OUR AREA...AND POSSIBLY ISOLATED SHOWERS IN FAR WESTERN MA/SW NH. HIGH TEMPS A FEW DEGREES BELOW NORMAL...MAINLY IN THE 50S. MON AND TUE... HIGH PRESSURE WILL SLIDE ACROSS THE REGION FROM THE SW ON MONDAY...WITH ABUNDANT SUNSHINE. A WARM FRONT WILL CROSS THE GREAT LAKES REGION ON MONDAY...THEN TRACK THROUGH AND NORTH OF OUR AREA ON TUESDAY. WHILE AN INCREASE IN CLOUDS IS EXPECTED WITH THE WARM FRONT...THE BETTER CHANCE FOR SHOWERS LOOKS TO BE MINIMAL. MAINLY DRY CONDITIONS ARE ANTICIPATED IN OUR AREA ON TUESDAY. TEMPERATURES ARE EXPECTED TO MODERATE...WITH HIGHS IN THE 60S ACROSS MANY LOCALES. TUE NIGHT AND WED... SFC COLD FRONT WILL BE SLIDING ACROSS THE REGION DURING THIS TIMEFRAME AS LOW PRES MOVES THROUGH QUEBEC. PWATS CLOSE TO THE COLD FRONT APPROACH 1.5 INCHES. ENOUGH INSTABILITY AVAILABLE FOR SHOWERS IN THE VICINITY OF THE FRONT BUT NOT ENOUGH FOR THUNDER AT THIS POINT. H850 WINDS 30 TO 40 KT SO SOME GUSTY WINDS WITH THE SHOWERS STILL POSSIBLE. THU AND FRI... CONTINUE TO EXPECT BRIEF RIDGING ON THURSDAY BEHIND THE FRONTAL PASSAGE. HOWEVER MODEL DISCREPANCIES EXIST ON THE DEVELOPMENT AND TRACK OF A POTENTIAL LOW PRESSURE SYSTEM. THE BRIEF HIGH PRES MAY GIVE WAY TO A COASTAL LOW PRESSURE SYSTEM AT THE END OF THE WORKWEEK...DEPENDING IN PART ON WHETHER OR NOT THE UPPER LEVEL TROUGH BECOMES A CUTOFF LOW. HAVE SLIGHT CHANCE TO CHANCE POPS FOR THURSDAY NIGHT AND ON. && .AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
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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 SATURDAY NIGHT/...HIGH CONFIDENCE. 2 AM UPDATE... TODAY...BACK EDGE OF MVFR CIGS ACROSS CENTRAL-EASTERN MA AND RI AT 06Z/2AM...AND CONTINUING TO MOVE EAST. THESE MVFR CIGS SHOULD EXIT THE CAPE AROUND 14Z-15Z. THEREAFTER VFR PREVAILS WITH LIGHT TO MODEST W WIND BECOMING SW TOWARD 21Z-00Z. TONIGHT...VFR TO START BUT THEN QUICKLY A BRIEF PERIOD OF MARGINAL MVFR/VFR CIGS MOVE ACROSS THE AREA ASSOCIATED WITH A COLD FRONT. LOW RISK OF A FEW SHOWERS ACROSS NORTHERN MA INTO SOUTHWEST NH 00Z-06Z. MAY SEE A FEW GUSTS UP TO 20 KT TOWARD DAYBREAK. SUNDAY...COLD FRONT MOVES OFFSHORE IN THE MORNING BUT LOTS OF POST FRONTAL CLOUDS IN THE BKN035-045 CATEGORY. LOW RISK OF A FEW LIGHT SHOWERS IN THE AFTERNOON. WEST WINDS WILL GUSTS 20-25 KT IN THE AFTERNOON. KBOS...HIGH CONFIDENCE IN TAF THRU 00Z...THEN SLIGHTLY LOWER CONFIDENCE ON TIMING OF MVFR/VFR CIGS. KBDL...HIGH CONFIDENCE IN TAF THRU 00Z...THEN SLIGHTLY LOWER CONFIDENCE ON TIMING OF MVFR/VFR CIGS. OUTLOOK...SUNDAY NIGHT THROUGH TUESDAY... HIGH CONFIDENCE. MAINLY VFR. SCATTERED SHOWERS TUESDAY NIGHT/WED MAY BRING LOCALIZED MVFR CONDITIONS.
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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 NIGHT/... 10 PM UPDATE... INCREASED WINDS SLIGHTLY FROM PREVIOUS FORECAST ALONG WITH SEAS A BIT HIGHER. OTHERWISE PREVIOUS FORECAST ON TRACK. EARLIER DISCUSSION BELOW. -------------------------------------------------------------------- TONIGHT...WINDS HAVE DIMINISHED BELOW SCA THRESHOLDS BUT SEAS REMAIN ABOVE 5 FT OVER THE EASTERN WATERS SO SCA WILL CONTINUE. SEAS SHOULD SUBSIDE BELOW 5 FT TOWARD DAYBREAK. SATURDAY...NW WINDS IN THE MORNING BECOME W/SW IN THE AFTERNOON AS COLD FRONT APPROACHES FROM THE WEST. WIND GUSTS TO 20 KT LIKELY DURING THE AFTERNOON. SEAS BELOW SCA. SATURDAY NIGHT...EXPECT INCREASING WEST WINDS THROUGH THE NIGHT AS COLD FRONT MOVES ACROSS THE WATERS. GOOD POST FRONTAL MIXING SUPPORTS WIND GUSTS TO 30 KT WITH BUILDING SEAS...ESPECIALLY OVER SOUTH COASTAL WATERS. SMALL CRAFT ADVISORIES WILL BE NEEDED. OUTLOOK...SUNDAY THROUGH TUESDAY... SUNDAY AND SUNDAY NIGHT...HIGH CONFIDENCE IN AT LEAST SMALL CRAFT ADVISORY CONDITIONS. NW WINDS WITH GUSTS OF 20 TO 30 KTS EXPECTED BEHIND A COLD FRONT THAT WILL BE MOVING OFFSHORE SUNDAY MORNING. SEAS 5-8 FT. LOW CHANCE FOR A PERIOD OF GALE FORCE GUSTS LATE SUN OR SUN NIGHT. MONDAY...MODERATE CONFIDENCE...SCA SEAS EXPECTED TO LINGER OVER THE COURSE OF THE DAY BUT GRADUALLY SUBSIDE. WINDS GRADUALLY DIMINISH AS WELL AS HIGH PRESSURE BUILDS OVER THE WATERS. TUESDAY...MODERATE CONFIDENCE...WINDS AND SEAS BELOW SCA THRESHOLD AS HIGH PRESSURE IS STILL OVER THE REGION. WEDNESDAY...LOW CONFIDENCE ON TIMING. COLD FRONT APPROACHES AND CROSSES THROUGH THE WATERS. SCA WINDS/SEAS POSSIBLE. && .BOX WATCHES/WARNINGS/ADVISORIES...
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CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EDT THIS MORNING FOR ANZ250- 254. SMALL CRAFT ADVISORY UNTIL 2 AM EDT EARLY THIS MORNING FOR ANZ251.
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&& $$ SYNOPSIS...KJC/NMB NEAR TERM...NOCERA SHORT TERM...KJC LONG TERM...NMB AVIATION...NOCERA/NMB MARINE...KJC/NOCERA/NMB

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