Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 211929 AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 329 PM EDT SUN SEP 21 2014 .SYNOPSIS... A COLD FRONT APPROACHES FROM THE WEST EARLY THIS EVENING...THEN CROSSES THE TRI-STATE THE REMAINDER OF THE NIGHT...MEANWHILE A COASTAL LOW TRACKS TO THE EAST...THEN NORTHEAST OF LONG ISLAND TONIGHT. HIGH PRESSURE THEN BUILDS IN FROM THE WEST THROUGH TUESDAY. THE HIGH THEN DOMINATES THE WEATHER THROUGH NEXT SUNDAY. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... 700-500 HPA TROUGH APPROACHES THIS EVENING THEN BEGINS TO CROSS THE TRI-STATE OVERNIGHT. RADAR TRENDS AND ALL GUIDANCE SUGGESTS THAT ANY -SHRA AHEAD OF IT AND ITS ASSOCIATED COLD FRONT WILL BE FALLING APART AS THEY APPROACH THE CWA. THIS IS DUE TO LOSS OF THERMODYNAMIC FORCING AFTER SUNSET AND BEST DYNAMICS STAYING TO THE NW/N. SO FOR NOW HAVE CHANCE POPS OVER FAR W ORANGE COUNTY TOWARDS MID EVENING...WITH SLIGHT CHANCE POPS OVER MOST OF THE REMAINDER OF THE NORTHERN TIER. FOR NOW BELIEVE PROBABILITY OF MEASURABLE PRECIPITATION IS LESS THAN 15 PERCENT ACROSS SOUTHERN ZONES...SO HAVE GONE WITH A DRY FORECAST THERE - HOWEVER A STRAY SHOWER OR TWO/SPRINKLE CANNOT BE COMPLETELY RULED OUT. FOR LOWS TONIGHT SUED A BLEND OF MAV/MET GUIDANCE WITH VALUES FORECAST TO BE 4 TO 8 DEGREES ABOVE NORMAL OUTSIDE OF THE NYC HEAT ISLAND...AND NEAR NORMAL INSIDE THE HEAT ISLAND AND AREAS TO THE N/W OF NYC DUE TO THE TIMING OF THE COLD FRONT. ALSO HAVE THE POTENTIAL FOR PATCHY FOG THIS EVENING OVER SE CT/THE TWIN FORKS AHEAD OF THE COLD FRONT. WHILE LOCALLY DENSE FOG CANNOT BE RULED OUT - AM CURRENTLY NOT CONFIDENT ENOUGH IN ITS POTENTIAL TO ISSUE ANY STATEMENTS. THERE IS A MODERATE RISK OF RIP CURRENTS AT ATLANTIC BEACHES THIS EVENING. && .SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/... REGION REMAINS UNDER THE BASE OF 700-500 HPA TROUGH MONDAY AND MONDAY NIGHT. WILL HAVE A FEW SHORTWAVES ROUND THE BASE OF THE TROUGH - BUT GIVEN FORECAST DRYING IN THE LOW LEVELS WOULD ONLY EXPECT AT MOST SOME CLOUDS AS THEY PASS. SO GOING WITH A MOSTLY SUNNY TO PARTLY CLOUDY SKY MONDAY AND A MOSTLY CLEAR TO CLEAR SKY MONDAY NIGHT AS A RESULT. FOR HIGHS MONDAY USED A BLEND OF MIXING DOWN FROM 875 HPA...EXCEPT 850 HPA OVER THE NW 1/4 OF THE CWA PER BUFKIT SOUNDINGS...WITH NAM 2-METER TEMPERATURES AND A BLEND OF MAV/MET GUIDANCE. EXPECT READINGS TO BE NEAR TO SLIGHTLY BELOW NORMAL. A BLEND OF MAV/MET GUIDANCE WAS USED FOR LOWS MONDAY NIGHT - WITH READINGS FORECAST TO BE 5-10 DEGREES BELOW NORMAL. LOWS IN THE UPPER 30S ARE POSSIBLE IN PORTIONS OF ORANGE COUNTY. && .LONG TERM /TUESDAY THROUGH SATURDAY/... A STRONG UPPER RIDGE WILL BE BUILDING INTO THE EAST COAST TUESDAY AND TUESDAY NIGHT...THEN REMAIN NEARLY STATIONARY THROUGH SUNDAY. AT THE SURFACE HIGH PRESSURE BUILDS EAST FROM THE OHIO VALLEY WHILE ANOTHER SURFACE HIGH BUILDS IN FROM CENTRAL CANADA. THE COMBINED HIGH PRESSURE CENTER WILL BUILD EAST FROM THE GREAT LAKES AND THROUGH NORTHERN NEW ENGLAND TUESDAY INTO WEDNESDAY. THE HIGH THEN BUILDS OVER THE REGION THURSDAY AND REMAINS NEARLY STATIONARY INTO SUNDAY. INITIALLY THE AIR MASS WILL BE COOL TUESDAY INTO THURSDAY...WITH SLIGHTLY BELOW SEASONAL NORMAL TEMPERATURES. A WARMING TREND SETS UP FOR THURSDAY NIGHT THROUGH SUNDAY AS THE AIR MASS MODIFIES. NEXT WEEKEND TEMPERATURES WILL HAVE REBOUNDED TO ABOVE SEASONAL NORMALS. && .AVIATION /19Z SUNDAY THROUGH FRIDAY/... WEAK LOW PRESSURE WILL PASS TO THE SE THIS AFTERNOON AND EVENING. A COLD FRONT WILL APPROACH THIS EVENING AND PASS THROUGH LATE TONIGHT...FOLLOWED BY BUILDING HIGH PRESSURE ON MONDAY. IFR CIGS ASSOCIATED WITH ONSHORE FLOW JUST AHEAD OF THE OFFSHORE LOW HAVE MOVED BACK IN AT KISP/KGON...AND ARE LIKELY TO REMAIN TONIGHT UNTIL COLD FROPA...THOUGH THEY MAY IMPROVE TO MVFR FOR A COUPLE OF HRS BEFORE FROPA LATE TONIGHT. ELSEWHERE...MVFR CIGS ELSEWHERE MAY BRIEFLY IMPROVE TO VFR LATE THIS AFTERNOON...BUT WITH NIGHTTIME COOLING EXPECT AT LEAST TEMPO MVFR CIGS TO RETURN TOWARD EVENING FOR 2-3 HRS BEFORE COLD FROPA. TIMING OF FROPA LOOKS TO BE 05Z KSWF...05Z-06Z NYC METRO...AND 07Z-08Z FARTHER EAST...WITH QUICK IMPROVEMENT TO VFR. WNW WINDS...WEST OF 310 MAGNETIC...AT 10-15 KT WITH GUSTS AROUND OR JUST OVER 20 KT...SHOULD DEVELOP BY 12Z MON. GUSTS COULD START A COUPLE HRS SOONER THAN FCST...AND COULD BRIEFLY TOUCH 25 KT IN NYC METRO BETWEEN 12Z-15Z. .OUTLOOK FOR 18Z MON THROUGH THU... .MON AFTERNOON/NIGHT...VFR. NW WINDS G20KT INTO EARLY EVENING. .TUE-THU...VFR. && .MARINE... SEAS BUILD TO UP TO 5 FT ON THE WESTERN COASTAL OCEAN WATERS AND UP TO 8 FT ON THE EASTERN COASTAL OCEAN WATERS BY LATE TONIGHT. WITH WIND GUSTS UP TO 25 KT ON THE COASTAL OCEAN WATERS ON MONDAY - HAVE CONVERTED SCA FOR HAZARDOUS SEAS TO A PLAIN SMALL CRAFT ADVISORY. SCA WIND GUSTS SHOULD LINGER OVER THE EASTERN TWO COASTAL WATER ZONES INTO MONDAY EVENING AND SCA LEVEL SEAS THROUGH THE NIGHT IN THOSE TWO ZONES...SO HAVE EXTENDED THE SCA FOR ANZ-350 AND 353 THROUGH 10Z TUESDAY AS A RESULT. ON THE REMAINDER OF THE COASTAL OCEAN WATERS SUB-SCA CONDITIONS ARE CURRENTLY EXPECTED THROUGH MONDAY NIGHT. WIND GUSTS TO 20 KT ARE FORECAST ON MONDAY - HOWEVER OCCASIONAL GUSTS TO 25KT CANNOT BE RULED OUT. THERE IS A CHANCE OF LINGERING 5 FOOT SEAS ACROSS THE EXTREME OUTER OCEAN WATERS EAST OF MORICHES INLET VERY EARLY TUESDAY MORNING AS SEAS WILL BE SUBSIDING AS HIGH PRESSURE BUILDS IN. WITH HIGH PRESSURE ACROSS THE WATERS TUESDAY INTO SATURDAY WIND AND SEAS ARE EXPECTED TO REMAIN BELOW SMALL CRAFT ADVISORY LEVELS. && .HYDROLOGY... LITTLE IF ANY ADDITIONAL RAINFALL IS EXPECTED THROUGH TONIGHT WITH THE PASSING OF A COASTAL LOW TO THE EAST AND THE PASSAGE OF A COLD FRONT. IT SHOULD THEN BE DRY FROM MONDAY THROUGH NEXT SUNDAY. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 6 PM EDT MONDAY FOR ANZ355. SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 6 AM EDT TUESDAY FOR ANZ350-353. && $$ SYNOPSIS...MALOIT/MET NEAR TERM...MALOIT SHORT TERM...MALOIT LONG TERM...MET AVIATION...GOODMAN MARINE...MALOIT/MET HYDROLOGY...MALOIT

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