Area Forecast Discussion
Issued by NWS Boston, MA

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000 FXUS61 KBOX 200850 AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 350 AM EST THU NOV 20 2014 .SYNOPSIS... MODERATING TEMPERATURES EXPECTED TODAY AHEAD OF A COLD FRONT...FOLLOWED BY MORE BLUSTERY AND UNSEASONABLY COLD CONDITIONS TONIGHT INTO FRIDAY NIGHT. A SIGNIFICANT WARM-UP IS IN STORE BY SUNDAY INTO EARLY NEXT WEEK AND THE MILDER AIR WILL LIKELY BE ACCOMPANIED BY RAIN SUNDAY NIGHT INTO MONDAY. COOLER WEATHER RETURNS BY THE MIDDLE OF NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... MID LEVEL DRYING MOVING IN FROM THE WEST HAS RESULTED IN PARTIAL CLEARING MOVING INTO W NEW ENG EARLY THIS MORNING...WHILE SCT SHOWERS ARE LIFTING NE FROM THE OCEAN. COLD FRONT OVER THE GT LAKES WILL MOVE EAST ACROSS SNE THIS AFTERNOON. GOOD SW LOW LEVEL JET AHEAD OF THE FRONT WILL BRING DEEPER MOISTURE AND INSTABILITY FROM THE OCEAN TO THE CAPE/ISLANDS WHERE MOCLOUDY SKIES AND A FEW SHOWERS ARE POSSIBLE INTO EARLY AFTERNOON. ELSEWHERE...CLEARING SKIES WILL MOVE IN FROM WEST TO EAST WITH INCREASING SUNSHINE. MODERATING LOW LEVEL TEMPS AHEAD OF THE FRONT...ESPECIALLY E NEW ENG WILL ALLOW TEMPS TO REACH WELL INTO THE 40S ACROSS THE COASTAL PLAIN TODAY...BUT COLDER 30S IN THE INTERIOR WHERE COLD ADVECTION MORE PRONOUNCED THIS AFTERNOON. GOOD MIXING OF LOW LEVEL WINDS WILL PROMOTE GUSTY W/SW WINDS WITH GUSTS TO 25 MPH INTERIOR AND 30-35 MPH IN THE COASTAL PLAIN. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/... TONIGHT... MID LEVEL TROF SWINGS THROUGH NEW ENG TONIGHT WITH GOOD COLD ADVECTION PROMOTING GUSTY W WINDS...ESPECIALLY NEAR THE COAST WHERE GUSTS TO 25-30 MPH POSSIBLE. THE TROF PASSAGE WILL BE ACCOMPANIED BY SOME CLOUDS...MAINLY N ZONES AS LAKE MOISTURE IS ADVECTED EASTWARD AHEAD OF THE TROF. ELSEWHERE...MOCLEAR SKIES EXPECTED. ANOTHER COLD NIGHT WITH MINS UPPER TEENS TO MID 20S...BUT IT WILL FEEL COLDER WITH THE WIND. FRIDAY... MID LEVEL TROF WILL BE MOVING EAST OF NEW ENG AS HIGH PRES BUILDS OVER THE OHIO VALLEY. THE COLUMN IS DRY WHICH WILL YIELD MOSUNNY SKIES BUT WITH UNSEASONABLY COLD TEMPS. 850 MB TEMPS -13/-14C SUPPORTS MAXES UPPER 20S TO NEAR 30 DEGREES NW HIGHER TERRAIN AND MID/UPPER 30S COASTAL PLAIN. GOOD PRESSURE GRADIENT AND DEEP MIXING WILL RESULT IN ANOTHER WINDY DAY WITH NW GUSTS TO 35 MPH WHICH WILL ADD TO THE CHILL. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
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HIGHLIGHTS... * MODERATING TEMPS THIS WEEKEND * MUCH WARMER SUNDAY THROUGH TUESDAY * RAINSTORM LIKELY SUNDAY AND MONDAY OVERVIEW AND MODEL PREFERENCES... 20.00Z MODEL GUIDANCE CONTINUES TO EXHIBIT REASONABLE AGREEMENT THROUGH THE MID TERM...WITH A DIVERGENCE IN SOLUTIONS AMONGST BOTH OPERATIONAL AND ENSEMBLES TOWARD THE LATTER PORTIONS OF THE LONG TERM. HOWEVER...GIVEN THE AGREEMENT IS THROUGH THE SECONDARY DEVELOPMENT AND PHASING OF BOTH NORTHERN AND SOUTHERN STREAM ENERGY FOR SUN-MON...CONFIDENCE REMAINS RELATIVELY HIGH FOR THE TIMING OF A FAIRLY DYNAMIC AND OCCLUDING. THIS OCCLUDING SYSTEM IS ASSOCIATED WITH ANOTHER DEEP LONGWAVE TROF WHICH LOOKS TO DEVELOP SIMILARLY TO THIS WEEKS COLD TROF. HOWEVER...THE AXIS IS SOMEWHAT UNCERTAIN AND MAY REMAIN W AND MAY NOT BE QUITE AS DEEP AS THIS WEEKS SYSTEM. AGREE WITH THE PREVIOUS FORECASTER THAT THE ECMWF HAS SHOWN BETTER CONSISTENCY WITH THIS DEVELOPING SYSTEM...SO WILL ERR ON THE SIDE OF THE ECMWF AFTER MON. DETAILS... FRI NIGHT AND SAT... THE LONGWAVE TROF WHICH BROUGHT THE COLDER THAN NORMAL WEATHER AND BLUSTERY CONDITIONS WILL MOVE TO THE E THROUGH THIS PERIOD AS RIDGE OF HIGH PRES CRESTS OVER FROM THE S. THIS WILL INITIATE MODEST RETURN FLOW WITH GULF OF MEXICO CONNECTIONS. ALTHOUGH THIS SUGGESTS WARMER TEMPS AND HIGHER DWPTS...THE COOL AIR WILL TAKE SOME TIME TO FULLY LEAVE THE LOW-LVLS...SO SUSPECT THAT HIGHS REMAIN NEAR OR SLIGHTLY BELOW NORMAL ON SAT IN SPITE OF RISING DWPTS AND RETURN FLOW. MAINLY DRY INTO SAT NIGHT. SUN AND MON... AS MENTIONED ABOVE A SLOWLY OCCLUDING LOW PRES WILL GRADUALLY APPROACH FROM THE W. FIRST IT/S WARM FRONT IS EXPECTED TO SLIDE INTO CENTRAL AND NRN NEW ENGLAND EARLY SUN...AND DEPENDING ON THE MOISTURE FLUX...MAY YIELD SOME MIXED PRECIP FOR THE INTERIOR...THIS WILL HAVE TO BE WATCHED GIVEN NEAR SFC TEMPS MAY BY BELOW FREEZING THROUGH MID MORNING. AFTER A BRIEF LULL DURING THE AFTERNOON/EVENING HOURS SUN...THE FRONTAL SYSTEM ALONG WITH A 60 KT SLY LLJ /3 STD DEVIATIONS ABOVE NORMAL/ ALONG WITH PWATS APPROACHING 1.25 INCHES /2-3 STD DEVIATIONS ABOVE NORMAL/. THIS YIELDS THE POTENTIAL FOR HEAVY RAIN AND RISING K-VALUES SUGGESTS SOME CONVECTIVE ELEMENTS. ALSO...THE STRONG JET COULD YIELD GUSTY WINDS AND THE POTENTIAL FOR WIND HEADLINES OR EVEN A FINE LINE THAT COULD BRING THESE WINDS TO THE SFC. THE WHOLE SYSTEM IS RELATIVELY PROGRESSIVE HOWEVER...BUT THIS WILL NEED TO BE MONITORED OVER THE NEXT SEVERAL RUNS. MON NIGHT INTO EARLY TUE... UPPER LVL SHORTWAVE AND SECONDARY FRONT SWEEP THROUGH THE AREA...ALTHOUGH DRIER AIR WILL BE MOVING IN...A FEW MORE SHOWERS MAY ACCOMPANY THIS FROPA. TUE THROUGH THU... AS MENTIONED BEFORE...A LONGWAVE TROF REMAINS TO THE W...BUT WITH SOUTHWESTERLY FLOW ALOFT AND HIGH PRES ATTEMPTING TO NOSE OVER FROM THE W...IT MAY BE THE DEEP COLD AIR REMAINS TO THE W. WILL YIELD A PERIOD OF MAINLY DRY WX...BUT TEMPERATURES WILL BE DEPENDENT ON EXACTLY HOW CLOSE THE TROF GETS BY THAT POINT. FOR NOW WILL GRADUALLY ALLOW TEMPS TO DROP FROM NEAR...TO SLIGHTLY BELOW NORMAL.
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&& .AVIATION /09Z THURSDAY THROUGH MONDAY/...
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FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM...HIGH CONFIDENCE. THROUGH 12Z...MAINLY VFR CIGS WITH POCKETS OF MVFR CAPE/ISLANDS. A FEW SHOWERS POSSIBLE CAPE/ISLANDS ALONG WITH SW GUSTS TO 25-30 KT. TODAY...VFR. CLEARING SKIES FROM WEST TO EAST...BUT VFR CIGS WILL PERSIST INTO THE AFTERNOON CAPE/ISLANDS AND CANT RULE OUT A FEW SHOWERS. SW WIND GUSTS TO 25-30 KT WITH A FEW HIGHER GUSTS CAPE/ISLANDS. TONIGHT...VFR CIGS NW...OTHERWISE MOSTLY CLEAR SKIES. WEST WIND GUSTS TO 25 KT ALONG THE IMMEDIATE COAST AND CAPE/ISLANDS. FRIDAY...VFR. NW WIND GUSTS TO 30 KT. KBOS TERMINAL...HIGH CONFIDENCE. KBDL TERMINAL...HIGH CONFIDENCE. OUTLOOK...FRIDAY NIGHT THROUGH MONDAY... FRIDAY NIGHT AND SATURDAY...HIGH CONFIDENCE. MAINLY VFR. INCREASING CLOUDS SATURDAY NIGHT. SUNDAY AND MONDAY...MODERATE CONFIDENCE. MVFR/IFR CONDITIONS LIKELY IN RAIN/FOG. MAY START AS A WINTRY MIX ACROSS THE NORTHWESTERN ZONES SUNDAY MORNING WITH A LULL INTO SUN EVENING. BEST TIMING FOR RAIN/FOG IS LATE SUN NIGHT INTO MON MORNING.
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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. HIGH CONFIDENCE THROUGH FRIDAY. PERSISTENT WIND GUSTS TO 30 KT EXPECTED INTO FRIDAY WITH A FEW PERIODS OF GALE FORCE WINDS POSSIBLE AS COLD AIR OVER WARMER WATERS PROMOTES GOOD MIXING. A PERIOD OF SW GALES EXPECTED TODAY OVER OPEN WATERS ASSOCD WITH THE LOW LEVEL JET...THEN ANOTHER PULSE POSSIBLE TONIGHT IN COLD ADVECTION BEHIND THE FRONT. IT APPEARS WINDS WILL FALL SHORT OF GALES ON FRIDAY...BUT NW GUSTS TO 30 KT EXPECTED. ROUGH SEAS UPWARDS TO 10-12 FT OVER SOUTHERN WATERS THROUGH TONIGHT...THEN SLOWLY SUBSIDING SEAS DURING FRIDAY. OUTLOOK...FRIDAY NIGHT THROUGH MONDAY... SATURDAY...HIGH CONFIDENCE. THERE WILL BE A BRIEF PERIOD OF BELOW SCA CONDITIONS DURING THE DAY SATURDAY...THEN SW WINDS AND SEAS PICK UP AGAIN SATURDAY NIGHT. SUNDAY AND MONDAY...MODERATE CONFIDENCE. SOUTH-SOUTHWESTERLY WINDS SHIFT TO THE SOUTHEAST SUNDAY EVENING THEN BACK TO THE SOUTHWEST MONDAY AFTERNOON AS A WARM FRONT MOVES OVER THE WATERS. SEAS GENERALLY 5 TO 9 FEET ON THE OUTER WATERS. SMALL CRAFT ADVISORIES LIKELY.
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&& .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...GALE WARNING UNTIL 7 PM EST THIS EVENING FOR ANZ232>234. SMALL CRAFT ADVISORY UNTIL 7 PM EST FRIDAY FOR ANZ230-236-251. GALE WARNING UNTIL 4 PM EST THIS AFTERNOON FOR ANZ231-250. GALE WARNING UNTIL 7 PM EST THIS EVENING FOR ANZ235-237. GALE WARNING UNTIL 3 AM EST FRIDAY FOR ANZ254>256. && $$ SYNOPSIS...KJC/DOODY NEAR TERM...KJC SHORT TERM...KJC LONG TERM...DOODY AVIATION...KJC/DOODY MARINE...KJC/DOODY

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