Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 212324 AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 624 PM EST FRI NOV 21 2014 .SYNOPSIS... HIGH PRESSURE MOVES NEARLY OVERHEAD TONIGHT BEFORE MOVING OFFSHORE ON SATURDAY. A WARM FRONT THEN MOVES ACROSS THE REGION LATE SATURDAY NIGHT. A WARM FRONT APPROACHES FROM THE SOUTH SUNDAY AND LIFTS ACROSS THE AREA SUNDAY NIGHT INTO MONDAY MORNING. A COLD FRONT MOVES THROUGH MONDAY NIGHT AND THEN STALLS OFFSHORE THROUGH THE MIDDLE OF THE WEEK. LOW PRESSURE MAY RIDE ALONG THE FRONT AND PASS TO THE EAST WEDNESDAY...WITH ANOTHER LOW POSSIBLY TRACKING EAST FRIDAY. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
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A LARGE 1035 MB SFC HIGH PRESSURE SYSTEM WAS CENTERED OVER WVA. IT WILL CONTINUE MVG SLOWLY ESEWD OFF THE MID ATLANTIC COAST TONIGHT. WINDS WILL CONT TO DECREASE FROM W TO E EARLY TONIGHT. SFC WINDS ARE FCST TO DECOUPLE FROM THE UPPER WIND FLOW AND CAUSE STRONG RADIATIONAL COOLING UNDER MOSTLY CLEAR SKIES. ANOTHER ...COLD... NIGHT IS IN STORE FOR THEM LOCAL AREA. USED A BLEND OF MET/MAV MOS GUIDANCE TO START...BUT THEN DROPPED LOWS FROM 5-7 DEGREES ACROSS THE INTERIOR PORTIONS OF THE LOWER HUDSON VALLEY AND SOUTHERN CT...AND ACROSS EASTERN LONG ISLAND. FLY IN THE OINTMENT COULD BE SOME WEAK H5 SHORTWAVE ENERGY THAT WILL MOVE ACROSS THE REGION AFTER 06Z SATURDAY. ANY CLOUDS THAT DEVELOP WILL INHIBIT RADIATIONAL COOLING...AND OVERNIGHT LOWS WILL BE WARMER THAN CURRENTLY FORECAST. ALSO...WITH SFC DEW POINTS MAINLY IN THE SINGLE DIGITS TO LOW TEENS...IT IS POSSIBLE THE CURRENT OVERNIGHT LOW TEMP FORECAST MAY NOT BE COLD ENOUGH IN SOME SPOTS. THE URBAN HEAT ISLAND EFFECT WILL KEEP OVERNIGHT LOWS IN NYC IN THE MID TO UPPER 20S. OTHERWISE...LOWS WILL DROP INTO THE UPPER TEENS TO AROUND 20 FOR MOST COASTAL AREAS...AND AS LOW AS THE SINGLE DIGITS TO LOW TEENS ACROSS THE INTERIOR. THESE TEMPS ARE 15-20 AND AS LOW AS 25 DEGREES BELOW NORMAL.
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&& .SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
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MOSTLY SUNNY FOR MUCH OF THE DAY SATURDAY AS HIGH PRES CONTINUES TO DEPART. SW FLOW WILL USHER A MILDER AIR MASS INTO THE REGION WITH HIGHS IN THE UPPER 30S ACROSS THE NORTHERN PORTIONS OF THE CWA...AND IN THE LOWER 40S ACROSS THE SOUTHERN PORTIONS. THESE TEMPS...HOWEVER...ARE STILL 10-15 DEGREES BELOW NORMAL. CLOUDS BEGIN TO INCREASE LATE IN THE DAY AND AT NIGHT AS A WARM FRONT APPROACHES FROM THE SOUTH AND WEST. SOME LIGHT...OVERRUNNING PRECIP WILL DEVELOP AFTER MIDNIGHT SATURDAY NIGHT. BEST FOCUS WILL BE ACROSS FAR NORTHERN ZONES WHERE POPS WILL BE LOW CHANCE...AND WILL CARRY SLIGHT CHANCE MOST ELSEWHERE. WITH SFC TEMPS BELOW FREEZING ACROSS INTERIOR PORTIONS OF NE NJ...THE LOWER HUDSON VALLEY...SOUTHERN CT AND THE PINE BARRENS OF EASTERN LONG ISLAND...PTYPE COULD BE FREEZING RAIN ACROSS NORTHERN ZONES AND FREEZING RAIN/RAIN FARTHER TO THE SOUTH. NYC/LONG ISLAND SHOULD STAY AS PLAIN RAIN...WITH SOME FREEZING RAIN POSSIBLE FOR THE PINE BARRENS OF LONG ISLAND. LOWS SATURDAY NIGHT WILL DROP INTO THE UPPER 20S TO LOW 30S INLAND AND IN THE MID/UPPER 30S ACROSS NYC/LONG ISLAND.
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&& .LONG TERM /SUNDAY THROUGH FRIDAY/... EARLY SUNDAY...WEAK SHORTWAVE ENERGY MOVES NORTH OF THE REGION...WITH UPPER RIDGING QUICKLY BUILDING DURING THE DAY. THIS IS IN RESPONSE TO DIGGING MID WEST TROUGH. THE RIDGE GIVES WAY TO SOUTHERN STREAM SHORTWAVE THAT TRACKS NORTHEAST...PASSING JUST TO THE WEST OF THE AREA EARLY MONDAY. MEANWHILE...MAIN TROUGH AMPLIFIES AND CLOSES OFF ACROSS THE UPPER MID WEST SUNDAY NIGHT AND MONDAY. THIS CLOSED LOW WEAKENS AND LIFTS NORTHEASTWARD THROUGH THE WEEK AS MAIN TROUGH SLOWLY MAKES EASTWARD PROGRESS. TROUGH AXIS MOVES OVERHEAD BY LATE IN THE WEEK. AT THE SURFACE...A WARM FRONT APPROACHES FROM THE SOUTH SUNDAY AS LOW PRESSURE TRACKS TOWARD THE GREAT LAKES REGION. THE WARM FRONT MOVES THROUGH EARLY MONDAY AS LOCAL AREA BECOMES WARM SECTORED. THE DEEP LOW PRESSURE PASSES ACROSS EASTERN CANADA AS A COLD FRONT MOVES THROUGH BY TUESDAY. THIS FRONT SETTLES EAST OF THE AREA MID WEEK AS A WAVE OF LOW PRESSURE RIDES ALONG IT...LIKELY PASSING JUST SOUTHEAST OF THE BENCHMARK. BY THURSDAY...LOW PRESSURE AND FRONT TO THE WEST APPROACHES. WITH UPPER TROUGH AXIS OVERHEAD LATE THURSDAY/FRIDAY...SFC LOW PRESSURE MAY INTENSIFY OFF THE MID ATLANTIC COAST FRIDAY. AS FOR WEATHER...ANY LINGERING LIGHT RAIN OR FREEZING RAIN ENDS SUNDAY. TEMPS WARM INTO THE LOWER 50S. WITH SOUTH WINDS...TEMPERATURES REMAIN RELATIVELY MILD SUNDAY NIGHT FOR THIS TIME OF YEAR...THEN WARM INTO THE 60S MONDAY AS AREA BECOMES WARM SECTORED. BEHIND THE COLD FRONT...EXPECT TEMPERATURES TO GRADUALLY FALL BACK CLOSER TO SEASONAL NORMS BY MID TO LATE WEEK. POPS AND WEATHER WILL DEPEND ON EVENTUAL PLACEMENT OF LOW PRESSURE MID WEEK AND AGAIN LATE WEEK. KEPT POPS IN THE CHANCE RANGE FOR NOW...WITH HIGHEST PROBABILITIES EAST OF NYC. WEATHER TYPE WILL BE DEPENDENT ON BOUNDARY LAYER TEMPERATURES. && .AVIATION /23Z FRIDAY THROUGH WEDNESDAY/... HIGH PRESSURE BUILDS IN FROM THE WEST TONIGHT AND PASSES SOUTH OF THE AREA SATURDAY. VFR THROUGH THE TAF PERIOD. FEW TO SCT CU THIS EVENING...WITH SOME MID AND HIGH LEVEL CLOUDS EXPECTED LATER TONIGHT AND SATURDAY MORNING. GUSTY NW WINDS DIMINISH THIS EVENING. WINDS SHIFT TO THE WEST AND WILL BE QUITE LIGHT LATE TONIGHT. SOUTHWEST WINDS INCREASE TO 8-12 KTS AFTER 14-15Z SATURDAY. ...NY METRO ENHANCED AVIATION WEATHER SUPPORT... DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE) KJFK FCSTER COMMENTS: WINDS DIMINISH EARLY THIS EVENING...AND GUSTS BECOME LESS FREQUENT. TIMING OF THIS TRANSITION MAY BE OFF AN HOUR OR TWO. OTHERWISE...WINDS RIGHT AROUND 310 MAGNETIC. KEWR FCSTER COMMENTS: WINDS DIMINISH EARLY THIS EVENING...AND GUSTS BECOME LESS FREQUENT. TIMING OF THIS TRANSITION MAY BE OFF AN HOUR OR TWO. OTHERWISE...WINDS RIGHT AROUND OR JUST LEFT OF 310 MAGNETIC. KLGA FCSTER COMMENTS: WINDS DIMINISH EARLY THIS EVENING...AND GUSTS BECOME LESS FREQUENT. TIMING OF THIS TRANSITION MAY BE OFF AN HOUR OR TWO. OTHERWISE...WINDS RIGHT AROUND 310 MAGNETIC. KTEB FCSTER COMMENTS: GUSTS BECOME LESS FREQUENT AFTER 22-23Z. KHPN FCSTER COMMENTS: GUSTS BECOME LESS FREQUENT AFTER 22-23Z. KISP FCSTER COMMENTS: GUSTS BECOME LESS FREQUENT AFTER 22-23Z. .OUTLOOK FOR 18Z SAT THROUGH WED... .SAT AFTERNOON-SAT NIGHT...VFR. SW WINDS 10-15 GUSTS UP TO 20 KT DURING THE DAYTIME. .SUN...VFR. .SUN NIGHT-MON...BECOMING MVFR/IFR. POSSIBLY SUB-IFR. RA AND FG WITH LLWS POSSIBLE. .MON NIGHT-TUE...VFR. .WED...MAINLY VFR...ALTHOUGH POSSIBLE RAIN OR A RAIN/SNOW MIX MAY IMPACT THE AREA...ESPECIALLY EAST OF NYC METRO. && .MARINE...
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THE SMALL CRAFT ADVISORY/SCA FOR EASTERN LONG ISLAND SOUND...THE SOUTH SHORE INLAND BAYS AND PECONIC AND GARDINERS BAY WAS EXTENDED UNTIL 10 PM FOR WIND GUSTS TO 25 KT. OTHERWISE...THE SCA FOR THE ATLANTIC COASTAL WATERS FROM FIRE ISLAND EAST REMAINS IN EFFECT UNTIL 1 AM SATURDAY. TRANQUIL CONDS THROUGH SATURDAY AFTERNOON WITH HIGH PRES BUILDING OVER THE WATERS. THAT HIGH MOVES OFFSHORE ON SATURDAY...AND THE GRADIENT TIGHTENS SATURDAY AFTERNOON. SCA CONDS LIKELY FOR AT LEAST THE OCEAN WATERS LATE SATURDAY AND SATURDAY NIGHT. WESTERLY WINDS SHIFT TOWARD THE SW SUNDAY AS A WARM FRONT APPROACHES. SOUTH WINDS ARE EXPECTED SUNDAY NIGHT AND MONDAY AHEAD OF AND THEN BEHIND THE FRONT...WITH A SLIGHT SHIFT FROM S/SE TO S/SW. THEN WINDS SHIFT AGAIN BACK TO THE WEST MONDAY NIGHT AND TUESDAY BEHIND THE COLD FRONT. THESE WINDS TURN TOWARD THE NW TUESDAY NIGHT AND WEDNESDAY AS HIGH PRESSURE BUILDS. DEVELOPING LOW PRESSURE EAST OF THE WATERS MAY TURN THE WINDS TOWARD THE N/NW LATE WEDNESDAY. WINDS REMAIN GUSTY THROUGH MUCH OF THE PERIOD. IN FACT GALES ARE POSSIBLE MONDAY BEHIND THE WARM FRONT AND AHEAD OF THE COLD FRONT. WINDS DO DIMINISH TUESDAY NIGHT INTO WEDNESDAY BRIEFLY AS THE HIGH BUILDS. SEAS SHOULD REMAIN ROUGH THROUGH MUCH OF THIS PERIOD.
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&& .HYDROLOGY... DRY CONDS THROUGH SATURDAY...AND ONLY LIGHT PRECIP POSSIBLE SATURDAY NIGHT THROUGH SUNDAY MORNING. && .OKX WATCHES/WARNINGS/ADVISORIES...
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CT...NONE. NY...NONE. NJ...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 1 AM EST SATURDAY FOR ANZ350-353. SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR ANZ330- 340-345.
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&& $$ SYNOPSIS...FIG/MPS NEAR TERM...GC/MPS SHORT TERM...MPS LONG TERM...FIG AVIATION...PW MARINE...GC/FIG/MPS HYDROLOGY...FIG/MPS

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