Area Forecast Discussion
Issued by NWS Boston, MA

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000 FXUS61 KBOX 050632 AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 132 AM EST THU MAR 5 2015 .SYNOPSIS... A FRONT WILL STALL SOUTH OF NEW ENGLAND OVERNIGHT. LOW PRESSURE WILL PUSH ALONG THE FRONT WITH ANOTHER ROUND OF SNOW OVERNIGHT INTO THURSDAY...MAINLY ACROSS SOUTHERN CT...RI...AND SOUTHEAST MA. HIGH PRESSURE WILL BUILD IN FOR FRIDAY THROUGH THIS WEEKEND...BRINGING DRY CONDITIONS WITH COLDER THAN NORMAL TEMPERATURES. A WEAKENING FRONT MAY BRING SOME LIGHT SNOW SHOWERS ON MONDAY. ANOTHER COLD FRONT MAY APPROACH TOWARD THE MIDDLE OF NEXT WEEK. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... 130 AM UPDATE... COLD FRONT HAS MADE ITS WAY TOWARD THE COAST AND AT 1 AM STRETCHED FROM NEAR MARSHFIELD MA TO GROTON CT. TEMPERATURES WERE SLOWLY FALLING BEHIND IT...NOW BELOW FREEZING IN THE BERKSHIRES. HOWEVER...DEWPOINTS WERE REALLY FALLING WITH READINGS IN THE UPPER TEENS AND LOWER 20S USHERING IN MUCH DRIER AIR INTO NORTHERN AND WESTERN MA. HENCE THE SHARP CUTOFF OF PRECIPITATION EXPECTED ON THE NORTHERN EDGE. TOUGH FORECAST BECAUSE SATELLITE IMAGERY SHOWS A VERY MOIST CONTINUOUS FEED FROM THE GULF TO SOUTHERN NEW ENGLAND. THUS...THE PRECIPITATION...WHICH WILL BE CHANGING OVER TO SNOW BY DAYBREAK... SHOULD CONTINUE FOR MOST OF THE DAY TODAY ALONG THE SOUTH COAST OF RI AND MA. THIS COULD AMOUNT TO A GOOD DEAL OF SNOW. BUT...FARTHER TO THE NORTH IT NOW LOOKS LIKE BOSTON...WORCESTER..AND SPRINGFIELD MAY NOT RECEIVE ANY SNOW. NEW WPC GRAPHIC CONFIRMS THIS THINKING. FOR THOSE WONDERING ABOUT BOS SNOWFALL RECORD...WE NEED 1.9 INCHES TO TIE 1995-96. OUR LATEST FORECAST HAS ABOUT 0.7 INCHES AT BOS BUT THIS MAY NOT EVEN PAN OUT. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM FRIDAY/... FOCUS FOR STEADIER SNOWFALL WILL BE OVER SE NEW ENGLAND THU MORNING WITH RAPID DRYING FROM NW BRINGING CLEARING TO INTERIOR BY AFTERNOON. EXPECT ADDITIONAL 2 TO 4 INCHES DURING DAY ACROSS S COASTAL RI/MA AND CAPE COD/ISLANDS WITH LESS THAN INCH AS FAR N AS MASS PIKE. DEFINITELY COLDER DAY AHEAD WITH HIGHS ONLY IN 20S EXCEPT NEAR 30 ON CAPE AND ISLANDS. CLEARING SETS IN ACROSS ALL OF REGION THU NIGHT AS SYSTEM HEADS FARTHER OUT TO SEA AND HIGH PRESSURE BUILDS IN. ANOTHER SHOT OF BITTERLY COLD AIR ARRIVES WITH LOWS FROM ABOUT 5 BELOW TO 5 ABOVE ACROSS INTERIOR TO TEENS CLOSER TO COAST. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... * HIGH PRESSURE ARRIVES FRIDAY * MOISTURE-STARVED COLD FRONT MOVES THROUGH THIS WEEKEND * UNCERTAIN FORECAST EARLY NEXT WEEK MODELS ARE IN FAIRLY GOOD AGREEMENT GOING INTO THIS WEEKEND. THERE ARE SOME MINOR DISCREPANCIES IN TIMING OF A COLD FRONT INTO THIS WEEKEND. MORE SIGNIFICANT DIFFERENCES DEVELOP SATURDAY NIGHT INTO SUNDAY. THE GFS IS VERY AGGRESSIVE IN DEVELOPING A SURFACE LOW NEAR THE GREAT LAKES...AND IS OFF ON ITS OWN IN DOING SO. AT THIS POINT...AM FAVORING A CONSENSUS BLEND OF THE OTHER GUIDANCE DUE TO FAIRLY BROAD MID-LEVEL TROUGH OVER THE NORTHEAST. HIGH PRESSURE SOUTH OF NEW ENGLAND IS THE MAIN THEME EARLY NEXT WEEK. THERE IS SOME QUESTION AS TO HOW CLOSE A COLD FRONT CAN GET TO SOUTHERN NEW ENGLAND TOWARD MID WEEK. FRIDAY...A HIGH PRESSURE BECOMES SUPPRESSED TO OUR SOUTH AS A LOW PRESSURE MOVES INTO QUEBEC. THIS WILL KEEP LOWER TEMPERATURES... WELL BELOW NORMAL FOR EARLY MARCH...IN PLACE FOR SOUTHERN NEW ENGLAND. THIS WEEKEND...A SHORTWAVE PUSHES LOW PRESSURE THROUGH QUEBEC... ALLOWING A COLD FRONT TO MOVE THROUGH SOUTHERN NEW ENGLAND. AT THIS POINT...THIS FRONTAL PASSAGE APPEARS TO BE FAIRLY MOISTURE- STARVED...SO LITTLE IF ANY PRECIP WILL ACCOMPANY THIS FRONT. TEMPERATURES MODERATE A BIT...BUT REMAIN WELL BELOW NORMAL. EARLY NEXT WEEK...MODELS CONTINUE TO SHOW SIGNIFICANT DIFFERENCES WITH THE EVOLUTION OF THE MID LEVEL FLOW. 04/12Z GFS IS FASTER TO WARM UP THE LOWER ATMOSPHERE THAN BOTH ITS ENSEMBLE MEAN AND THE 04/12Z ECMWF. WHILE THINKING TEMPERATURES WILL EVENTUALLY BECOME HIGHER...AM NOT YET SOLD ON THE GFS TIMING. THIS WILL HAVE IMPLICATIONS FOR PRECIPITATION TYPE. WILL CONTINUE TO FAVOR A CONSENSUS APPROACH FOR THIS TIME RANGE. && .AVIATION /07Z THURSDAY THROUGH MONDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH THURSDAY NIGHT/...MODERATE CONFIDENCE. POCKETS OF IFR PERSIST ACROSS PORTIONS OF CAPE COD AND THE ISLANDS. VFR WITH ISOLATED MVFR CIGS ELSEWHERE. MVFR/IFR SPREADS N IN LIGHT SNOW TOWARD DAYBREAK...PROBABLY AS FAR N AS KIJD-SFZ-KPYM...MAINLY DUE TO VSBY. LIGHT RAIN CHANGES TO SLEET AND SNOW CLOSER TO S COAST AFTER 09Z WHERE LIFR EXPECTED THROUGH DAYBREAK THU. VFR CIGS FARTHER N AND W. MVFR CIGS ALSO SPREADING FROM THE BERKSHIRES INTO WESTERN MA AND WESTERN CT BETWEEN 06Z AND 09Z. CONDITIONS SLOWLY IMPROVE THU FROM NW TO SE...WITH CAPE COD AND ISLANDS LAST TO IMPROVE 16Z-20Z. EXPECTED GENERAL SNOW ACCUMULATIONS... BOS/BAF/BDL/BED/ORH...LITTLE OR NO SNOW PVD...2 INCHES FMH/HYA...3-4 INCHES ACK...5-7 INCHES KBOS TAF...HIGH CONFIDENCE. KBDL TAF...HIGH CONFIDENCE. OUTLOOK...FRIDAY THROUGH MONDAY... MODERATE CONFIDENCE. MAINLY VFR THROUGH THIS PERIOD. BRIEF MVFR CONDITIONS ARE POSSIBLE SATURDAY NIGHPREVIOUS DISCUSSION... && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH THURSDAY NIGHT/...MODERATE CONFIDENCE. MAINTAINING SCA ON OUTER WATERS AND BLOCK ISLAND/RI SOUNDS PRIMARILY DUE TO SEAS THROUGH THU OR THU NIGHT. COLD FRONT APPROACHING THE COAST AS OF 1 AM. IT WILL DROPS S OVERNIGHT WITH WIND SHIFT TO NW AND POSSIBLY A FEW GUSTS TO 25 KT. SPOTTY LIGHT RAIN WILL GIVE WAY TO SLEET AND SNOW TOWARD DAYBREAK. SNOW SHOULD MAINLY AFFECT S COASTAL WATERS THU BEFORE HEADING OFFSHORE THU NIGHT. HIGH PRESSURE BUILDING IN TO REGION MAY BRING PERIOD OF 25KT NW WIND GUSTS THU NIGHT...MAINLY ON OUTER WATERS. OUTLOOK...FRIDAY THROUGH MONDAY... HIGH CONFIDENCE. WINDS AND SEAS SLOWLY DIMINISH FRIDAY AS HIGH PRESSURE BUILDS OVER THE WATERS. THEY THEN INCREASE AGAIN...BUT ONLY MODESTLY OVER THIS WEEKEND AS A COLD FRONT APPROACHES...THEN CROSSES THE WATERS. SMALL CRAFT ADVISORIES WILL LIKELY BE NECESSARY ON THE OUTER WATERS FOR A PORTION OF THIS TIME. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR MAZ023- 024. WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR MAZ020>022. RI...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR RIZ008. WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR RIZ003>007. MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ235-237-250- 254>256. && $$ SYNOPSIS...BELK/JWD/GAF NEAR TERM...GAF SHORT TERM...JWD LONG TERM...BELK AVIATION...JWD/GAF MARINE...JWD/GAF

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