Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 311518 AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 1118 AM EDT FRI OCT 31 2014 .SYNOPSIS... LOW PRESSURE DEVELOPS OFF THE CAROLINA COAST TODAY...THEN TRACKS NORTHEAST TO A POSITION SOUTHEAST OF CAPE COD BY SATURDAY EVENING. MEANWHILE...ANOTHER COASTAL LOW DEVELOPS OFF THE CAROLINA COAST LATE SATURDAY...THEN TRACKS NORTHEAST TO THE CANADIAN MARITIME PROVINCES BY SUNDAY EVENING. HIGH PRESSURE BUILDS IN BEHIND THIS STORM INTO TUESDAY. A WARM FRONT WILL PASS TO THE NORTH ON TUESDAY...FOLLOWED BY A SERIES OF FAST MOVING COLD FRONTS DURING THE MIDDLE OF NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/...
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LOW PRESSURE OFF THE CAROLINA COAST WITH HIGH PRESSURE TO THE NORTH. A 700 HPA SHORTWAVE...CURRENTLY OVER N CENTRAL GA...ROUNDING THE BASE OF A DEEP LAYERED TROUGH WILL INTERACT WITH THIS LOW AND HAVE IT TRACK SLOWLY NE AND DEEPEN THROUGH THE DAY. MEANWHILE...A NORTHERN STREAM SHORTWAVE OVER THE OHIO RIVER VALLEY CURRENTLY...WILL WORK TO FORM AN INVERTED TROUGH TO THE N-NW OF THIS LOW BY THIS AFTERNOON. MODELS HAVE BEEN CONSISTENT IN HAVING AN AREA OF ISOLD-SCT -SHRA TRACK FROM OFF THE LI COAST BACK TOWARDS W/NW THIS AFTERNOON. HAVE SLIGHT CHANCE POPS IN FOR THIS AS COVERAGE LIKELY WILL BE SPARSE AND INTENSITY QUITE LIGHT. OTHERWISE...EXPECT CLOUDS TO INCREASE FROM THE COMBINATION OF MOISTURE BEING TRAPPED UNDER AN INVERSION NEAR 850 MB AND HIGHER LEVEL CLOUDS STREAMING IN FROM THE SOUTH. TEMPS ON TRACK AND HIGHS SHOULD BE A FEW DEGREES BELOW NORMAL.
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&& .SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/... ALL MODELS ARE CONSISTENT IN TAKING A DEVELOPING CUTOFF LOW DOWN INTO THE CAROLINAS BY SATURDAY MORNING...THEN LIFTING IT EAST THEN NORTHEAST AS IT OPENS TO NEAR/OFF THE MID ATLANTIC COAST BY LATE SATURDAY NIGHT. THE RESULT WILL BE SPOTTY LIGHT RAIN BECOMING LIKELY BY LATE TONIGHT ACROSS ROUGHLY THE S 1/2 OF THE CWA AND A CHANCE OF LIGHT RAIN N. THE SPOTTY RAIN WILL CONTINUE ON SATURDAY...BECOMING MORE PERIODIC BY AFTERNOON OVER THE S 1/2 OF THE CWA. PRECIPITATION THEN TAPERS OFF FROM NW TO SE AS THE SURFACE LOW EXITS WELL TO THE NE SATURDAY NIGHT. FOR NOW IT APPEARS THAT IN MOST AREAS...THE PRECIPITATION WILL COME TO AN END BEFORE ENOUGH LOW LEVEL COLD AIR COMES IN TO CAUSE ANY MIXING WITH OR CHANGE TO SNOW. A POSSIBLE EXCEPTION COULD BE ELEVATIONS ABOVE 1000-1500 FT ACROSS MAINLY INTERIOR PORTIONS OF S CT...WHERE THE COLD AIR MIGHT ARRIVE IN TIME TO CAUSE A FEW FLAKES OF SNOW TO MIX IN...IF NOT BRIEFLY CHANGE TO ALL SNOW...BEFORE ENDING. AT THIS TIME IT APPEARS EVEN AT HIGHER ELEVATIONS THAT THERE WILL BE LITTLE IF ANY SNOW ACCUMULATION FROM THIS SYSTEM. THE MAIN THREAT FROM THIS SYSTEM IS STRONG GUSTY WINDS. WINDS SHOULD GUSTS TO UP TO 30-35 MPH BY SATURDAY AFTERNOON OVER EASTERN PORTIONS OF THE AREA AND 25-30 MPH OVER WESTERN PORTIONS. AS THE STORM CONTINUES TO STRENGTHEN AS IT PULLS AWAY THERE IS THE POTENTIAL FOR GUSTS OF 35 TO 45 MPH OVER MAINLY S CT/LONG ISLAND AND POSSIBLY NYC/FAR E PORTIONS OF NE NJ SATURDAY NIGHT. FOR NOW FORECASTING WINDS TO REMAIN JUST UNDER ADVISORY CRITERIA. HOWEVER...WOULD NOT BE SURPRISED IF A WIND ADVISORY WAS ULTIMATELY NEEDED FOR AT LEAST E SUFFOLK COUNTY AND SE CT. THIS IS HIGHLY DEPENDENT ON THE EXACT TRACK AND STRENGTH OF THE LOW - BUT BASED ON LATEST GUIDANCE IT APPEARS THAT THE STRONGEST WINDS WITH THIS SYSTEM WILL BE JUST TO THE EAST OF THE CWA. TEMPERATURES TONIGHT-SATURDAY NIGHT: FOR LOWS TONIGHT USED A BLEND OF MAV/MET/ECS GUIDANCE WITH NAM 2-METER TEMPERATURES...EXPECT VALUES TO BE AROUND 5 DEGREES ABOVE NORMAL. A BLEND OF ECS/MET/MAV GUIDANCE WITH NAM 2-METER TEMPERATURES AND A MIX DOWN FROM 950 HPA NEAR THE COAST AND 925 HPA INLAND...PER BUFKIT SOUNDINGS...WAS USED FOR HIGHS ON SATURDAY. READINGS SHOULD BE AROUND 5 TO MAYBE 10 DEGREES BELOW NORMAL. ON SATURDAY NIGHT...A BLEND OF NAM 2-METER TEMPERATURES WITH MAV/MET GUIDANCE WAS USED FOR LOWS...WITH VALUES FORECAST TO BE NEAR TO SLIGHTLY BELOW NORMAL. && .LONG TERM /SUNDAY THROUGH THURSDAY/... HIGH PRESSURE BUILDS IN BEHIND THE DEPARTING STORM ON SUNDAY...AND THE RESULTING TIGHT PRESSURE GRADIENT WILL SUSTAIN WINDY CONDITIONS ACROSS THE AREA FOR THE DAYTIME BEFORE GRADUALLY DIMINISHING SUNDAY NIGHT. FORECAST BOUNDARY LAYER WINDS COULD SUPPORT ADVISORY CRITERIA WIND GUSTS DURING THE DAY...PARTICULARLY FOR THE COASTAL AREAS. SOME SPOTS COULD EVEN REACH CRITERIA BASED ON SUSTAINED WINDS. ASIDE FROM THIS...PARTLY CLOUDY AND DRY CONDITIONS EXPECTED WITH BELOW NORMAL HIGHS. WIND CHILLS AT DAYBREAK WILL BE AROUND 30 DEGREES. HIGH PRESSURE THEN CONTINUES TO BUILD IN ON MONDAY AND MOVES OFFSHORE ON TUESDAY. DRY BOTH DAYS WITH MODERATING TEMPERATURES. FOR WEDNESDAY...A WEAK COLD FRONT APPROACHES...BUT IS MOISTURE STARVED. JUST A SLIGHT CHANCE OF SHOWERS NORTH OF THE CITY. A STRONGER COLD FRONT THEN FOLLOWS...AND IS PROGGED TO PASS THROUGH SOMETIME THURSDAY OR THURSDAY NIGHT. POPS EVENTUALLY CLIMB INTO THE CHANCE CATEGORY ACROSS THE ENTIRE AREA WITH THE PASSAGE OF THIS FRONT. && .AVIATION /15Z FRIDAY THROUGH TUESDAY/...
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LOW PRESSURE OFF THE CAROLINA COAST WILL INTENSIFY AS IT MOVES NORTHEAST...PASSING SOUTHEAST OF CAPE COD SATURDAY EVENING. ANOTHER LOW IS FORECAST TO DEVELOP OFF THE CAROLINA COAST LATE SATURDAY AND TRACK ACROSS THE CANADIAN MARITIME PROVINCES SUNDAY EVENING. MORNING TAFS ON TRACK. WILL MAKE MINOR ADJUSTMENTS BASED ON LATEST SFC OBS AND SATELLITE TRENDS. N/NE WINDS WILL VEER TO THE NE AT 10-15 KT AS THE MORNING PROGRESSES. BY 06Z SAT...NE WINDS WILL INCREASE TO AROUND 15 KT WITH GUSTS UP TO 20 KT. AFT 15Z SAT...NE WILL INCREASE TO 20-25 KT WITH GUSTS OF 30-35 KT. CLOUDS...VFR CIGS 4000-5000 FT. MVFR CIGS FORECAST MAINLY AFTER SUNSET...WITHIN 2 HOURS OF FORECAST TIME. LIGHT RAIN POSSIBLE ALONG THE COAST FROM 18Z - 21Z. ...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: LIGHT RAIN POSSIBLE AFT 18Z...MVFR CIGS POSSIBLE WITHIN 2 HOURS EITHER SIDE OF FORECAST. KLGA FCSTER COMMENTS: LIGHT RAIN POSSIBLE AFT 18Z...MVFR CIGS POSSIBLE WITHIN 2 HOURS EITHER SIDE OF FORECAST. KEWR FCSTER COMMENTS: LIGHT RAIN POSSIBLE AFT 18Z...MVFR CIGS POSSIBLE WITHIN 2 HOURS EITHER SIDE OF FORECAST. THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD. KTEB FCSTER COMMENTS: TIMING THE DEVELOPMENT OF RAIN AND MVFR CIGS WITHIN 2 HOURS EITHER SIDE OF FORECAST. KHPN FCSTER COMMENTS: TIMING THE DEVELOPMENT OF RAIN AND MVFR CIGS WITHIN 2 HOURS EITHER SIDE OF FORECAST. KISP FCSTER COMMENTS: TIMING THE DEVELOPMENT OF RAIN AND MVFR CIGS WITHIN 2 HOURS EITHER SIDE OF FORECAST. .OUTLOOK FOR 15Z SATURDAY THROUGH TUESDAY... .SATURDAY-SATURDAY NIGHT...MVFR OR LOWER IN RAIN. NE WINDS BACKING TO THE NORTH AT 20-25KT WITH 30-35KT GUSTS. .SUNDAY...VFR. NW WINDS 20-30 KT WITH 30-40 KT GUSTS. .MONDAY AND TUESDAY...VFR.
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&& .MARINE...
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A RELAXED PRESSURE GRADIENT OVER THE WATERS SHOULD KEEP WINDS TO AROUND 15 KT OR LESS TODAY. THE PRESSURE GRADIENT TIGHTENS TONIGHT IN RESPONSE TO A STORM SYSTEM DEVELOPING TO THE S AND HIGH PRESSURE BUILDING INTO THE SW...THIS SHOULD BRING GUSTS TO 25-30 KT TO ALL WATERS TONIGHT...SO HAVE CONTINUED A SMALL CRAFT ADVISORY THEN. THE HIGH MOVES CLOSER TO THE AREA SATURDAY-SUNDAY...AND A SERIES OF STRENGTHENING COASTAL LOWS RESULT IN A CONTINUING TIGHTENING OF THE PRESSURE GRADIENT OVER THE WATERS. THIS LIKELY WILL RESULT IN GUSTS TO GALE FORCE OVER ALL WATERS DURING THE DAY ON SATURDAY...WITH WIND GUSTS INCREASING TO 40-45 KT SATURDAY NIGHT...WITH THESE GUSTS INTO SUNDAY. SEAS WILL BUILD AS A RESULT TO 5-10 FT ON THE COASTAL OCEAN WATERS AND 3-5 FT ON THE EASTERN SOUND BY SATURDAY NIGHT. N-NW GALES CONTINUE ON ALL WATERS DURING THE DAY ON SUNDAY...THEN WINDS START TO DIMINISH AT NIGHT. BY MONDAY MORNING...ALL WATERS SHOULD BE BELOW GALE FORCE GUSTS...HOWEVER SCA CONDITIONS WILL LIKELY PREVAIL ACROSS THE OCEAN AND EASTERN WATERS THROUGH A GOOD PORTION OF THE DAY. LOOKS LIKE IT WILL TAKE UNTIL LATE MONDAY NIGHT FOR SUB-SCA CONDITIONS TO REACH ALL OF THE WATERS WHEN A HIGH PRESSURE RIDGE REACHES THE EASTERN SEABOARD A RETURN WSW FLOW FOR TUESDAY SHOULD REMAIN ADVISORY CRITERIA.
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&& .HYDROLOGY... DRY THROUGH THIS MORNING...THEN LIGHT PRECIPITATION DEVELOPS INTO TONIGHT. A MORE STEADY/LIGHT-MODERATE RAIN IS FORECAST FROM SATURDAY INTO SATURDAY NIGHT - WITH THE BEST CHANCE OVER S/E AREAS. FOR NOW FORECASTING TOTAL RAINFALL FROM FRIDAY NIGHT- SATURDAY NIGHT RANGING FROM AROUND A TENTH AN INCH OVER ORANGE COUNTY TO A HALF AND INCH TO MAYBE THREE QUARTERS OF AN INCH OVER SE CT/E SUFFOLK COUNTY. GIVEN THE EXPECTED DURATION OF PRECIPITATION OF 24+HOURS...NO SIGNIFICANT HYDROLOGIC IMPACT IS ANTICIPATED FROM THIS SYSTEM AT THIS TIME. NO SIGNIFICANT PRECIPITATION IS EXPECTED FROM SUNDAY INTO THE MIDDLE OF NEXT WEEK. && .OKX WATCHES/WARNINGS/ADVISORIES...
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CT...NONE. NY...NONE. NJ...NONE. MARINE...SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 6 AM EDT SATURDAY FOR ANZ330-335-338-340-345-350-353-355. GALE WARNING FROM 6 AM EDT SATURDAY TO 5 PM EST SUNDAY FOR ANZ330-335-338-340-345-350-353-355.
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&& $$ SYNOPSIS...JC/MALOIT NEAR TERM...MALOIT/PW SHORT TERM...MALOIT LONG TERM...JC AVIATION...MPS MARINE...JC/MALOIT/PW HYDROLOGY...JC/MALOIT/PW

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