Area Forecast Discussion
Issued by NWS Boston, MA

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000 FXUS61 KBOX 251031 AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 521 AM EST WED FEB 25 2015 .SYNOPSIS... SNOW ALONG THE I-95 CORRIDOR QUICKLY COMES TO AN END BY 6 AM...BUT COULD LINGER A TAD LONGER ACROSS THE CAPE/NANTUCKET. OTHERWISE...TURNING PARTLY TO MOSTLY SUNNY WITH A GUSTY WEST WIND DEVELOPING THIS AFTERNOON. A REINFORCING SURGE OF COLD BUT DRY WEATHER RETURNS WEDNESDAY NIGHT THROUGH FRI NIGHT. TEMPS SLOWLY MODERATE SAT AS HIGH PRES BUILDS INTO THE REGION...THEN A FRONTAL SYSTEM MAY BRING SOME SNOW LATE SUN INTO MON. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 530 AM UPDATE... SNOW HAS ENDED FOR ALL AREAS EXCEPT THE CAPE AND NANTUCKET. THEREFORE...HAVE CANCELLED WINTER WEATHER ADVISORY FOR ALL AREAS BUT CAPE/NANTUCKET WHERE SNOW WILL END BY 6 OR NO LATER THAN 7 AM. SNOW ACCUMS OF 2 TO 4 INCHES WILL BE COMMON IN THE BOSTON TO PROVIDENCE CORRIDOR POINTS SOUTH AND EAST. ISOLATED 5 INCH AMOUNTS MAY HAVE OCCURRED NEAR THE SOUTH COAST/CAPE COD. MEANWHILE...THERE WAS A VERY SHARP CUTOFF TO THE NORTHWEST EXTENT OF THE ACCUM SNOW AND NOTHING MORE THAN FLURRIES FELL FROM WILLIMANTIC...TO WORCESTER TO JUST NORTHWEST OF LAWRENCE. OTHERWISE...SKIES WERE ALREADY BEGINNING TO CLEAR AND PARTLY TO MOSTLY SUNNY SKIES ARE EXPECTED FOR MOST OF THE DAY. HIGH TEMPS SHOULD RECOVER INTO THE UPPER 20S TO LOWER 30S...BUT IT WILL BE BLUSTERY WITH WESTERLY WIND GUSTS BETWEEN 20 AND 30 MPH BY AFTERNOON. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM THURSDAY/... WINDS DIMINISH THIS EVENING WITH THE LOSS OF DAYTIME HEATING. LOW TEMPS A BIT UNCERTAIN BECAUSE SKIES SHOULD START OFF MOSTLY CLEAR...BUT A FAIR AMOUNT OF MID/HIGH LEVEL CLOUDINESS MAY WORK IN FROM THE WEST AFTER MIDNIGHT. GIVEN DEEP SNOW PACK...TEMPS MAY DROP FAIRLY QUICKLY THIS EVENING IN THE OUTLYING LOCATIONS. THEN THEY MAY LEVEL OFF A BIT DEPENDING ON HOW THICK THE MID/HIGH LEVEL CLOUDINESS ENDS UP. FOR NOW WILL GO WITH LOWS MAINLY IN THE SINGLE DIGITS ACROSS MOST AREAS...BUT SOME BELOW ZERO READINGS ARE LIKELY IN THE COLDEST OUTLYING LOCATIONS. MEANWHILE...IN THE URBAN CENTERS OF BOSTON AND PROVIDENCE SHOULD SEE LOW TEMPS IN THE 10 TO 15 DEGREE RANGE. && .LONG TERM /THURSDAY THROUGH TUESDAY/... HIGHLIGHTS... * OCEAN EFFECT SNOW POSSIBLE ON THE CAPE THURSDAY * HIGH PRESSURE EXPECTED THROUGH THE WEEKEND * COLD FRONT BRINGS WINTRY PRECIP SUNDAY INTO MONDAY * ANOTHER STORM POSSIBLE TUESDAY INTO WEDNESDAY OVERVIEW AND MODEL PREFERENCES... JUST SUBTLE ENOUGH OF A SHIFT IN THE OVERALL PATTERN TO SUPPRESS STORM TRACK BOTH TOO FAR SOUTH AND TOO FAR NORTH TO BRING ANY SIGNIFICANT STORMS TO NEW ENGLAND IN THE MID AND LONG TERMS. AO/NAO REMAIN PRIMARILY POSITIVE...SUGGESTING THAT THE PATTERN REMAINS PROGRESSIVE OFFSHORE. HOWEVER...NOW NOTE A NEGATIVE SHIFT IN THE PNA...WHICH HAS ALLOWED THE ATLANTIC RIDGE OF HIGH PRES JUST N OF THE EQUATOR TO RETROGRADE A BIT AND MORE STRONGLY INFLUENCE THE WX ACROSS SRN NEW ENGLAND. THIS SUPPRESSES THE FIRST COUPLE OF WAVES DIVING S FROM NRN QC BY STRETCHING THEM IN THE FAST FLOW CREATED BETWEEN THE RIDGE TO THE S AND THE LONGWAVE TROF OVER ERN CANADA. THIS PREVENTS THE RAPID DEEPENING OF MOST OF THESE SYSTEMS IN THE WEEKEND...SOMETHING EVEN THE ECENS/GEFS SHOW REASONABLE CLUSTERING ON. THE BIGGEST DIFFERENCES START EARLY NEXT WEEK AS THERE IS AN ATTEMPT TO JOIN THE SRN AND NRN STREAMS FROM THE GREAT LAKES INTO THE NE CONUS...WHICH COULD BETTER FEATURE LOW PRES EFFECTING THE REGION BEGINNING AS AN INSIDE RUNNER. DETAILS... THU AND FRI... NOSE OF HIGH PRES MOVING IN FROM THE W ALONG WITH SUPPRESSED UPPER LVL JET WILL KEEP STORM WELL ENOUGH OFFSHORE FOR LITTLE IMPACT ON SRN NEW ENGLAND. ONLY CAVEAT WILL BE THE THREAT FOR SOME OCEAN EFFECT SNOW SHOWERS MAINLY FOR CAPE COD ON THU AND THU NIGHT AS THE UPPER LVL WAVE CATCHES UP AND H85 TEMPS DROP TO BELOW -12C. TEMPS GENERALLY BELOW NORMAL...BUT NOT AS SIGNIFICANTLY SO AS OTHER DAYS THIS SEASON. SAT AND SUN... HIGH PRES REMAINS IN CONTROL CRESTING SAT NIGHT INTO EARLY SUN. MID AND UPPER LVL TEMPS REMAIN GENERALLY BELOW -10C UNTIL SUN...AT WHICH POINT SLIGHT WARM ADVECTION WILL ALLOW THEM TO REACH -6C OR SO. THEREFORE...MINS FRI AND SAT WILL BE GENERALLY IN THE NEGATIVE TO POSITIVE SINGLE DIGITS. HIGHS SAT WILL BE MAINLY BELOW NORMAL...BUT THEN CLOSER TO MAYBE EVEN SLIGHTLY ABOVE NORMAL ON SUN. SUN NIGHT INTO MON... LOW PRES PASSING WILL TO THE N WILL PUSH A COLD FRONT ACROSS THE REGION SUN NIGHT INTO MON. NOTING ENOUGH F-GEN WITH EVEN A POSSIBLE SUBTROPICAL MOISTURE CONNECTION. THEREFORE...EXPECT WIDESPREAD PRECIP ACROSS THE REGION. AT THIS TIME...IT APPEARS THE LOW-MID LVLS ARE COLD ENOUGH FOR SNOW...ESPECIALLY GIVEN DYNAMIC COOLING MAY BE ABLE TO OVERCOME DIURNAL WARMING MON MORNING. QPF VALUES REMAIN AT ISSUE GIVEN THAT SUBTROPICAL CONNECTION WHICH IS FEATURED IN SOME MODELS BUT NOT OTHERS. THEREFORE...SNOWFALL TOTALS COULD STAY BELOW OR JUST EXCEED ADVISORY LEVELS. TUE INTO WED... WILL NEED TO KEEP AN EYE ON YET ANOTHER INSIDE RUNNER WHICH WILL FORCE THE COLD FRONT STALLING OFFSHORE FROM MON...TO SHIFT N AS A WARM FRONT. OVERRUNNING SITUATION GIVEN THE DEEP SNOWPACK REMAIN ACROSS THE REGION AND COLD AIR LOCKED IN WITH 1035 HIGH PRES NEAR NEW BRUNSWICK SUGGEST P-TYPE ISSUES WHICH WILL HAVE TO BE WATCHED. THIS SYSTEM IS STRONGER AND HAS AN EVEN BETTER CONNECTION TO SUBTROPICAL MOISTURE THAN DOES THE PREVIOUS SO THIS WILL LIKELY BE THE SYSTEM TO WATCH AS IT APPROACHES. && .AVIATION /12Z WEDNESDAY THROUGH SUNDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /TODAY THROUGH WEDNESDAY/... TODAY...HIGH CONFIDENCE. SNOW ALREADY ENDING IN THE BOSTON TO PROVIDENCE CORRIDOR AND SHOULD EXIT MOST OTHER AREAS BY 10 OR 11Z... PERHAPS LASTING A TAD LONGER ACROSS THE CAPE/NANTUCKET. OTHERWISE...VFR CONDITIONS WITH WESTERLY WIND GUSTS OF 20 TO 25 KNOTS DEVELOPING BY AFTERNOON. WINDS THEN WILL DIMINISH EARLY THIS EVENING. KBOS TAF...HIGH CONFIDENCE. VFR BY 10 OR 11Z. KBDL TAF...HIGH CONFIDENCE IN VFR CONDITIONS. OUTLOOK...THURSDAY THROUGH SUNDAY... THU AND FRI...HIGH CONFIDENCE. MAINLY VFR. ALTHOUGH PERIODS OF MVFR/IFR POSSIBLE MAINLY FOR CAPE COD TERMINALS IN OCEAN EFFECT SNOWS. SAT AND SUN...HIGH CONFIDENCE. MAINLY VFR. ALTHOUGH SOME SNOW IS POSSIBLE LATE SUN FROM W TO E WITH MVFR/IFR CONDITIONS POSSIBLE. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /TODAY AND TONIGHT/... TODAY AND TONIGHT...SNOW AND REDUCED VSBYS SHOULD END BY MID MORNING. OTHERWISE...WEST TO NORTHWEST WIND GUSTS OF 25 KNOTS EXPECTED BEHIND A COLD FRONT LATER THIS MORNING INTO THIS EVENING. SCA HEADLINES FOR ALL WATERS EXCEPT NARR BAY. OUTLOOK...THURSDAY THROUGH SUNDAY... THU AND FRI...MODERATE CONFIDENCE. LEFTOVER AND LINGERING SWELL CAUSED BY LOW PRES MOVING WELL OFFSHORE MAY REQUIRE SMALL CRAFT ADVISORY HEADLINES ON THE OCEAN WATERS...WHERE WAVES COULD REACH 5-6FT AT TIMES. WINDS HOWEVER...OUT OF THE N...NE WILL REMAIN BELOW 25 KT. SAT AND SUN...MODERATE CONFIDENCE. A PERIOD OF MAINLY QUIET BOATING WEATHER EXPECTED AS HIGH PRES MOVES OVER THE WATERS. WINDS AND SEAS MAINLY BELOW SMALL CRAFT ADVISORY HEADLINES. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...WINTER WEATHER ADVISORY UNTIL 7 AM EST THIS MORNING FOR MAZ022- 024. RI...NONE. MARINE...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 1 AM EST THURSDAY FOR ANZ230>235-237-251. SMALL CRAFT ADVISORY UNTIL 1 AM EST THURSDAY FOR ANZ250- 254>256. && $$ SYNOPSIS...FRANK/DOODY NEAR TERM...FRANK SHORT TERM...FRANK LONG TERM...DOODY AVIATION...FRANK/DOODY MARINE...FRANK/DOODY

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