Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 300307 AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 1107 PM EDT WED OCT 29 2014 .SYNOPSIS... A COLD FRONT MOVED EAST OF THE AREA EARLY THIS EVENING. HIGH PRESSURE BUILDS IN BEHIND THE FRONT TONIGHT INTO THURSDAY NIGHT. AN ALBERTA CLIPPER TYPE LOW WILL HEAD SOUTHEAST FROM THE GREAT LAKES TO THE CAROLINA COAST ON FRIDAY...WHILE ANOTHER LOW DEVELOPS OFF THE SOUTHERN MID ATLANTIC COAST FRIDAY NIGHT. THE FIRST LOW WILL PASS TO THE SOUTHEAST FRIDAY NIGHT INTO SATURDAY MORNING...WHILE THE SECOND INTENSIFIES AND ALSO PASSES TO THE SOUTHEAST FROM LATE SATURDAY INTO SUNDAY MORNING. HIGH PRESSURE WILL BUILD FROM THE WEST LATER SUNDAY INTO TUESDAY. A WEAK COLD FRONT WILL APPROACH ON WEDNESDAY. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... COOLER AND DRIER AIR CONTINUES TO MOVE IN QUICKLY BEHIND THE COLD FRONT EAST OF THE REGION...AS DOES THE AREA OF SHOWERS. UPDATED TO REFLECT THE CURRENT TRENDS. POST FRONTAL SHOWERS ACROSS SOUTHEASTERN CONNECTICUT AND EASTERN LONG ISLAND CONTINUE TO WEAKEN AND MOVE QUICKLY EAST. THE UPPER TROUGH WAS MOVING A LITTLE FASTER THAN FORECAST AND HAVE ENDED THE PRECIPITATION LATE TONIGHT. POPS REMAIN AT LOW CHANCE AND SLIGHT CHANCE. TEMPERATURES HAVE FALLEN QUICKLY BEHIND THE FRONT AS COLDER AIR MOVES IN...IN A COUPLE OF HOURS TEMPERATURES WERE DOWN AS MUCH AS 15 DEGREES. DEW POINTS ALSO HAVE FALLEN. WITH THE ONSET OF THE COLDER AND DRIER AIR GUSTS OF 20 TO 25 KT WERE OBSERVED AND THEN ALSO QUICKLY DIMINISHED AS A WEAKER PRESSURE GRADIENT MOVED INTO THE REGION. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/... DRY WEATHER EXPECTED THROUGH THE SHORT TERM AS HIGH PRESSURE BUILDS IN FROM THE WEST. NORTHWEST FLOW PREVAILS THROUGH THE DAY. EXPECT MOSTLY CLEAR SKIES THROUGH THE PERIOD. MAV/MET TEMPERATURE GUIDANCE IN GOOD AGREEMENT AND WAS ACCEPTED. EXPECT HIGHS ON THURSDAY TO CLIMB INTO THE 50S AND LOWER 60S. THURSDAY NIGHT WILL BE COLD WITH TEMPERATURES RANGING FROM THE LOWER 30S TO MIDDLE 40S. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... MODELS STILL IN FAIRLY GOOD AGREEMENT ON A POTENT NRN STREAM VORT...NOW OVER NUNAVUT IN NORTHERN CANADA...WILL DIVE SE TO THE GREAT LAKES BY FRI AND CARVE OUT A FULL LATITUDE TROUGH AND SIGNIFICANT CLOSED LOW. THE CLOSED LOW WILL CONTINUE SE TO THE CAROLINAS ON SAT...THEN PASS OFF THE MID ATLANTIC COAST WHILE ALSO NEGATIVELY TILTING THE PARENT UPPER TROUGH. THE APPROACH OF THIS COMBO OF UPPER SYSTEMS WILL PROMOTE WEAK CYCLOGENESIS ALONG A FRONTAL ZONE OFF THE CAROLINA COAST. AS THIS LOW APPROACHES...LOW LEVEL FLOW WILL TURN EASTERLY AND BEGIN TO MOISTEN ON FRI...AND A WEAK LEADING MID LEVEL SHORTWAVE INTERACTING WITH A WEAK LOW LEVEL TROUGH EXTENDING NW FROM THE INCIPIENT OFFSHORE LOW TO WARRANT SLIGHT CHANCE POP FOR SOME LIGHT SHOWERS MAINLY OVER LONG ISLAND BY LATE DAY FRI OR EARLY FRI EVENING...THEN INCREASING POP TO CHANCE AND THEN LIKELY MOST PLACES DURING THE DAY ON SAT AND CAT ACROSS ERN LONG ISLAND AS THE OFFSHORE LOW MAKES ITS CLOSEST PASS. THEN AS THE POTENT CLOSED LOW ROUNDS THE BASE OF THE PARENT UPPER TROUGH...A STRONGER LOW SHOULD DEVELOP ALONG THE NORTH CAROLINA COAST LATE DAY SAT INTO SAT EVENING...AND THEN HEAD NE...PASSING OUTSIDE THE 40N/70W BENCHMARK LATE SAT NIGHT INTO SUNDAY. THE CLOSED LOW SHOULD REMAIN A SEPARATE ENTITY FROM THE LARGER TROUGH...AND THIS LACK OF PHASING SHOULD PRECLUDE THE AREA FROM SEEING HEAVY PRECIP...SO ACTUALLY HAVE DECREASING POP DURING SAT NIGHT. ENOUGH COLD AIR SHOULD STILL POUR IN BEHIND THE LOW TO POSSIBLY CAUSE ANY LINGERING PRECIP TO MIX WITH OR CHANGE TO SNOW...BUT WITH LITTLE TO NO ACCUMULATION. THE BIGGEST IMPACTS FROM THIS SYSTEM WILL BE A SHOT OF COLD AND WIND FROM SAT NIGHT INTO EARLY NEXT WEEK. EXPECT TEMPS TO BE ON THE COLD SIDE OF THE GUIDANCE BLEND... WITH LOWS SAT NIGHT IN THE 30S AREA-WIDE...THEN HIGHS ONLY IN THE 40S ON SUNDAY AS WINDS GUST CLOSE TO 40 MPH...WITH WIND CHILLS IN THE 30S. TEMPS SUNDAY NIGHT SHOULD FALL TO AOB FREEZING EVERYWHERE EXCEPT NYC SUNDAY NIGHT. AS HIGH PRESSURE BUILDS ACROSS EARLY NEXT WEEK AND HEIGHTS SLOWLY RISE ALOFT...EXPECT GRADUAL MODERATION...WITH TEMPS STILL BELOW NORMAL MON-TUE...THEN REACHING NEAR NORMAL LEVELS ON WED AS A WARM FRONT PASSES WELL TO THE NORTH. AN APPROACHING WEAK COLD FRONT MAY BRING ISOLD SHOWERS ON WED. && .AVIATION /03Z THURSDAY THROUGH MONDAY/...
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COLD FRONT HAS PASSED EAST OF THE TERMINALS WITH HIGH PRESSURE OVER THE MID SECTION OF THE COUNTRY BUILDING EAST THROUGH THE END OF THE WEEK. THIS WILL RESULT IN A W-NW FLOW AT 5 TO 10 KT. WIND DIRECTION IS FORECAST TO BE MAINLY RIGHT OF 310 MAGNETIC...WITH A PERIOD THU AFTERNOON WHERE THE FLOW MAY BACK 20 TO 30 DEGREES. VFR WITH A SCT-BKN CU 4-5 KFT ON THU. .OUTLOOK FOR 00Z FRIDAY THROUGH MONDAY... .THURSDAY NIGHT-FRIDAY...VFR. .FRIDAY NIGHT-SATURDAY NIGHT...MVFR OR LOWER LIKELY. PRECIP MAINLY RAIN...BUT SNOW MAY MIX IN ACROSS THE INTERIOR SATURDAY NIGHT. NE-N WINDS 15-20G25-30KT. .SUNDAY...IMPROVING CONDS. NW WINDS 15-20G25-30KT. .MONDAY...VFR. WEST WINDS 5-10 KT.
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&& .MARINE... HIGH PRESSURE WILL SLOWLY BUILD IN BEHIND A COLD FRONT EAST OF THE WATERS THROUGH THURSDAY NIGHT. WIND AND SEAS WILL REMAIN BELOW SMALL CRAFT LEVELS INTO THURSDAY NIGHT. SCA CONDS ARE LIKELY TO DEVELOP ON ALL WATERS FROM LATE FRI NIGHT INTO SAT MORNING AS NE FLOW STRENGTHENS...THEN EXPECT NORTHERLY GALES ON THE OCEAN BY SAT AFTERNOON...AND N-NW GALES ON ALL WATERS ESPECIALLY THE OCEAN AND THE ERN SOUND/BAYS SAT NIGHT INTO SUNDAY. CONDS SHOULD THEN GRADUALLY SUBSIDE FROM SUNDAY NIGHT ON...WITH SUB-SCA CONDS ON THE SOUND/HARBOR/BAYS BY MON MORNING...AND ON THE OCEAN BY MON NIGHT. && .HYDROLOGY... LIGHT PRECIP EXPECTED FROM FRI NIGHT INTO EARLY SUNDAY MORNING. IF OFFSHORE LOW PRESSURE TRACKS CLOSER TO THE COAST SAT NIGHT... EASTERN LONG ISLAND AND SE CT COULD SEE MORE SIGNIFICANT RAINFALL AMTS CLOSER TO 1/2 INCH. NO SIGNIFICANT HYDROLOGIC IMPACT EXPECTED. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...NONE. && $$ SYNOPSIS...BC/GOODMAN/MET NEAR TERM...MET SHORT TERM...BC LONG TERM...GOODMAN AVIATION...DW MARINE...BC/GOODMAN/MET HYDROLOGY...BC/GOODMAN/MET

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