Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 300757 AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 357 AM EDT THU OCT 30 2014 .SYNOPSIS... HIGH PRESSURE BUILDS OVER THE AREA THROUGH TONIGHT. LOW PRESSURE DEVELOPS OFF THE MID ATLANTIC COAST FRIDAY. ..THEN TRACKS NORTHEAST TO EAST OF CAPE COD BY SATURDAY EVENING. MEANWHILE A SECONDARY LOW FORMS OFF THE MID-ATLANTIC COAST SATURDAY...THEN TRACKS NORTHEAST TO THE CANADIAN MARITIME PROVINCES BY SUNDAY EVENING. HIGH PRESSURE BUILDS IN BEHIND THIS STORM THROUGH MONDAY NIGHT...THEN MOVES OFFSHORE ON TUESDAY. A WARM FRONT CROSSES THE AREA TUESDAY NIGHT...FOLLOWED BY A COLD FRONT APPROACHING ON WEDNESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... PATCHY FOG...LOCALLY DENSE HAS DEVELOPED MAINLY OVER THE HIGHER ELEVATIONS TO THE W/N OF NYC METRO. HAVE ADDRESSED WITH AN SPS. DO THINK IT WILL DISSIPATE AS LOWER DEWPOINTS CONTINUE TO ADVECT IN...BY 11Z. HAVE SEEN SOME IMPROVEMENT IN VISIBILITIES WITH 7Z OBSERVATIONS IN SUPPORT OF THIS LINE OF THINKING...SO WILL EXTEND SPS UNTIL 11Z. OTHERWISE...PASSAGE OF 700-500 HPA TROUGH AXIS TODAY WILL ONLY PRODUCE SOME SCT CLOUDS AS AROUND 10KT OR DOWNSLOPE BOUNDARY LAYER FLOW SERVES AS A LIMITING FACTOR. FOR HIGHS TODAY USED A BLEND OF MAV/MET/ECS GUIDANCE WITH NAM 2-METER TEMPERATURES AND A MIX DOWN FROM 900-875 HPA PER BUFKIT SOUNDINGS. EXPECT HIGHS TO BE NEAR TO SLIGHTLY BELOW NORMAL. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/... A 850-500 HAP SHORTWAVE RIDGE CROSSES THE AREA TONIGHT...WITH ASSOCIATED SUBSIDENCE PROMOTING MINIMAL CLOUD COVER AND DIMINISHING WINDS. AS A RESULT...HAVE TRENDED TOWARDS LOWER OF MET/MAV/ECS GUIDANCE AND NAM 2-METER TEMPERATURES FOR LOWS. NOT QUITE CERTAIN ENOUGH OF A COMPLETELY CLEAR SKY AND LIGHT WINDS TO GO COLDER AT THIS TIME. LOWS SHOULD BE NEAR TO SLIGHTLY BELOW NORMAL. A WEAK INVERTED TROUGH EXTENDS NNW FROM COASTAL LOW DEVELOPING OFF THE VA/NC COAST FRIDAY TOWARDS LONG ISLAND. THIS COUPLED WITH A PASSING WEAK 700-500 HPA SHORTWAVE WARRANTS INCREASING CLOUD COVER OVER THE ENTIRE REGION AND SLIGHT CHANCE POPS FOR -SHRA OVER MAINLY LONG ISLAND FRIDAY AFTERNOON. FOR HIGHS FRIDAY...A BLEND OF MAV/MET/ECS GUIDANCE WITH NAM 2-METER TEMPERATURES AND A MIX DOWN FROM 900-875 HPA PER BUFKIT SOUNDINGS. HIGHS SHOULD BE AROUND 5 DEGREES BELOW NORMAL. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... A STRONG SHORTWAVE ENERGIZES A SURFACE LOW EMERGING OFF THE CAROLINA COAST LATE FRIDAY NIGHT. MODEL CONSENSUS AND THEIR RESPECTIVE ENSEMBLE MEANS STRENGTHEN THIS STORM AS IT HEADS NE...PASSING SE OF THE 40N/70W BENCHMARK LATE SATURDAY NIGHT INTO SUNDAY MORNING. A SURFACE TROUGH FIRST BRINGS A CHANCE OF SHOWERS TO THE AREA FRIDAY NIGHT. AT LEAST CHANCE POPS REMAIN ON SATURDAY WITH SOME MID LEVEL LIFT...ALTHOUGH MODEL QPF OUTPUT SUGGESTS THAT COASTAL AREAS WARRANT LIKELY POPS...BEING CLOSER TO THE STORM CENTER. CHANCES OF RAINFALL THEN DIMINISH THROUGH SATURDAY NIGHT AS THE STORM SHIFTS FARTHER OUT TO SEA...WITH DRY WEATHER BY SUNDAY MORNING. THERMAL PROFILES SUGGEST AN ALL RAIN EVENT. BY THE TIME FREEZING LEVELS AND WET BULB ZEROES LOWER ENOUGH TO SUPPORT A MIX OF RAIN AND SNOW...PRECIPITATION WILL HAVE ENDED OR WILL JUST ABOUT TO END. THIS WOULD BE THE CASE FOR ELEVATIONS ABOVE 1000 FT NORTH AND WEST OF THE CITY. WITH SUCH LIMITED COVERAGE OF A LOW PROBABILITY EVENT...HAVE REMOVED THE MENTION OF SNOW FROM THE GRIDS. WINDS WILL END UP BEING THE BIGGER STORY...AND WILL BE AT THEIR STRONGEST FROM SATURDAY AFTERNOON THROUGH SUNDAY AFTERNOON. COULD GET CLOSE TO WIND ADVISORY CRITERIA AT SOME POINT DURING THIS PERIOD...SO WILL NEED TO KEEP AN EYE ON THIS. WITH HIGH PRESSURE IN CONTROL...SUNDAY THROUGH TUESDAY IS EXPECTED TO BE DRY. HIGHS ON SUNDAY AVERAGING AT LEAST 10 DEGREES BELOW NORMAL...WITH WIND CHILL VALUES AROUND 30 DEGREES FOR THE FIRST HALF OF THE MORNING. THE GROWING SEASON THEN PROBABLY ENDS FOR MORE OF THE ZONES OUTSIDE OF THE CITY SUNDAY NIGHT WITH LOWS AROUND THE FREEZING MARK. TEMPS THEN BEGIN THEIR CLIMB BACK TOWARDS NORMAL ON MONDAY...BEFORE REACHING NEAR NORMAL ON TUESDAY WITH A SW FLOW. NEXT CHANCE OF SHOWERS THEN ARRIVES TUESDAY NIGHT INTO WEDNESDAY WITH A WARM FRONT PASSAGE FOLLOWED BY THE APPROACH OF A COLD FRONT ON WEDNESDAY. && .AVIATION /07Z THURSDAY THROUGH MONDAY/... HI PRES BUILDS OVER THE METRO TODAY. LOW PRES BEGINS TO DEVELOP S OF THE REGION FRI. VFR THRU THE TAF PERIOD...EXCEPT FOR FG WHICH COULD BRING THINGS TO LIFR AT KSWF AND PERHAPS AT KHPN/KTEB. GREATEST LIKELIHOOD AT KSWF WHERE A TEMPO WAS INCLUDED IN THE TAF. MAINLY NW WINDS AT OR BELOW 10KT. SOME BACKING TO THE WNW THIS AFTN...ESPECIALLY S COASTS. DIRECTION VEERS TO THE N OVERNIGHT. .OUTLOOK FOR 06Z FRIDAY THROUGH MONDAY... .THU NGT...VFR. .FRI...CIGS LOWER THRU THE DAY WITH MVFR POSSIBLE LATE. .FRI NGT-SAT NGT...MVFR OR LOWER. PCPN MAINLY RAIN...BUT SNOW MAY MIX IN ACROSS THE INTERIOR AT NGT. NE-N WINDS 15-20G25-35KT. .SUNDAY...VFR. NW WINDS 15-20G25-30KT. .MONDAY...VFR. WEST WINDS 5-10 KT. && .MARINE... A RELAXED PRESSURE GRADIENT OVER THE WATERS AROUND LONG ISLAND WILL RESULT IN WINDS 10 KT OR LESS THROUGH FRIDAY. THE ONLY EXCEPTION TO THIS IS POSSIBLY OVER THE FAR EASTERN COASTAL OCEAN WATERS ON FRIDAY AFTERNOON...WHERE NE FLOW COULD STRENGTHEN TO UP TO 15 KT. AS A RESULT...SUB-SMALL CRAFT CONDITIONS ARE EXPECTED ON ALL MARINE ZONES THROUGH FRIDAY. SCA CONDITIONS ARE LIKELY TO DEVELOP ON ALL WATERS FROM FRIDAY 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. CONDITIONS SHOULD THEN GRADUALLY SUBSIDE FROM SUNDAY NIGHT ON...WITH SUB-SCA CONDITIONS ON THE SOUND/HARBOR/BAYS BY MON MORNING...AND ON THE OCEAN BY MON NIGHT. && .HYDROLOGY... DRY THROUGH FRIDAY MORNING. THERE IS A SLIGHT CHANCE OF AT MOST A FEW HUNDREDTHS OF AN INCH OF RAINFALL FRIDAY AFTERNOON MAINLY ACROSS LONG ISLAND. RAINFALL FROM FRIDAY NIGHT THROUGH SATURDAY NIGHT IS EXPECTED TO REMAIN UNDER A HALF INCH WITH THE HIGHER AMOUNTS GENERALLY ACROSS THE COASTAL AREAS. NO SIGNIFICANT HYDROLOGIC IMPACT IS EXPECTED. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...NONE. && $$ SYNOPSIS...MALOIT/JC NEAR TERM...MALOIT SHORT TERM...MALOIT LONG TERM...JC AVIATION...JMC MARINE...MALOIT HYDROLOGY...MALOIT/JC

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