Area Forecast Discussion
Issued by NWS Upton, NY

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469 FXUS61 KOKX 051902 AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 302 PM EDT THU MAY 5 2016 .SYNOPSIS... LOW PRESSURE WELL OFF THE MID ATLANTIC COAST WILL MOVE TOWARD NOVA SCOTIA THROUGH TONIGHT. ANOTHER OFFSHORE LOW WILL MOVE SLOWLY NORTH UP THE MID ATLANTIC COAST FRIDAY AND FRIDAY NIGHT...THEN WEAKEN NEARBY ON SATURDAY. A COLD FRONT WILL APPROACH FROM THE WEST SATURDAY NIGHT...THEN MOVE ACROSS ON SUNDAY. HIGH PRESSURE WILL BUILD IN EARLY NEXT WEEK. A WARM FRONTAL BOUNDARY MAY APPROACH MID WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... LATEST HIGH-RES GUIDANCE INDICATES POTENTIAL FOR BREAKS IN THE CLOUDS THIS AFTERNOON...AS MOIST H-9 LAYER DRIES OUT SOMEWHAT IN BETWEEN A MID LEVEL SHORTWAVE PASSING TO THE WEST AND LOW PRESSURE PASSES TO THE EAST. AS A RESULT BUMPED UP HIGH TEMPS PER GFS LAMP FCST...WITH MID/UPPER 50S FOR MOST OF THE AREA...BUT STILL LOWER 50S FOR ERN CT/LONG ISLAND CLOSER TO THE OFFSHORE LOW TRACK AND WHERE RADAR IS NOW SHOWING DRIZZLE DRIFTING IN FROM OFF THE OCEAN. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/... WENT MAINLY DRY THIS EVENING AS MID LEVEL ALSO DRY OUT IN BETWEEN ONE DEPARTING LOW AND ANOTHER APPROACHING LOW...THEN LIKELY POP FOR RAIN LATE TONIGHT FOR NYC METRO/NE NJ AND CHANCE ELSEWHERE EXCEPT SE CT AND FAR ERN LONG ISLAND...AS FORCING WITH UPPER LOW MOVES IN FROM THE SOUTH...AND AS A WEAK OFFSHORE LOW DEVELOPING OFF HATTERAS THIS EVENING PIVOTS BACK IN CLOSER TO THE DELMARVA COAST IN RESPONSE TO THIS FORCING. THIS GENERAL SETUP CONTINUES ON FRIDAY...WITH H5 COLD POOL ALSO MOVING ACROSS...AND SHOWALTER INDICES FALLING TO -2 TO +2. AS A RESULT...LIKELY/CAT POP FOR RAIN WITH SLIGHT CHANCE FOR ELEVATED THUNDER FRI AFTERNOON. LOWS TONIGHT SHOULD BE NEAR TO SLIGHTLY BELOW AVG. HIGHS ON FRI SHOULD BE IN THE 50S...10-15 DEG BELOW AVG. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... MODEL GUIDANCE IS IN GOOD AGREEMENT WITH THE GENERAL H5 FLOW ACROSS NORTH AMERICA THROUGH THE MIDDLE OF NEXT WEEK. AS USUAL...THERE ARE SOME TIMING AND AMPLITUDE DIFFERENCES THAT START TO DEVELOP OVER THE WEEKEND...ALTHOUGH THE GENERAL IDEA IS THAT THE PERSISTENT BLOCKED UPPER PATTERN ACROSS THE CONUS WILL FINALLY LOSE ITS GRIP NEXT WEEK. CUTOFF LOW PRES NEAR THE MID ATLANTIC COAST FRI NIGHT WILL GRADUALLY WEAKEN WHILE SLOWLY MOVING E THROUGH SAT NIGHT. MEANWHILE...A SHORTWAVE TROUGH DIVING OUT OF CENTRAL CANADA CUTS OFF OVER ONTARIO WITH THE TWO SYSTEMS CONSOLIDATING INTO A BROAD VORTEX OVER SE CANADA. THIS SYSTEM WILL GRADUALLY LIFT NE INTO THE MARITIMES EARLY NEXT WEEK AS RIDGING OVER THE UPPER MIDWEST FLATTENS WITH A SW UPPER FLOW DEVELOPING BY THE MIDDLE OF NEXT WEEK. AT THE SFC...WEAK SFC LOW PRES NEAR THE DELAWARE/NJ COAST GRADUALLY WEAKENS S OF THE AREA THROUGH THE DAY SAT. WIDESPREAD RAIN WILL GRADUALLY DRY OUT ACROSS THE AREA WITH DRY WEATHER RETURNING BY SAT NIGHT. THE STRENGTH AND EXACT TRACK OF THIS LOW STILL REMAIN IN QUESTION WHICH WILL IMPACT WIND STRENGTH/DIRECTION AND ULTIMATELY ANY CONTINUED COASTAL FLOOD IMPACTS ON SAT. SEE COASTAL FLOOD SECTION BELOW FOR MORE INFORMATION. A COLD FRONT APPROACHES FROM THE WEST SAT NIGHT AND TRACKS THROUGH ON SUN...BRINGING ANOTHER ROUND OF SHOWERS TO THE AREA. THERE ARE TIMING DISCREPANCIES WITH THIS...WITH THE EC BEING SLIGHTLY FASTER THAN THE GFS. THE BIGGER ISSUE THAT NEEDS TO BE RESOLVED IS THAT THE GFS IS INDICATING MAINLY POST-FRONTAL PRECIPITATION AND REALLY WRAPS THE SYSTEM UP ONCE IT PUSHES THROUGH RESULTING TO A MUCH STRONGER PRESSURE PATTERN ACROSS THE AREA. RIDGING THEN RETURNS THROUGH EARLY NEXT WEEK WITH TEMPERATURES GRADUALLY RETURNING TO NEAR TO ABOVE NORMAL LEVELS. A WARM FRONT APPROACHING FOR THE MIDDLE OF THE WEAK HAS THE POTENTIAL TO STALL OVER OR NEAR THE AREA WITH WAVES OF LOW PRES TRACKING ALONG IT. THERE IS HIGH BUST POTENTIAL IN THE TEMP FORECAST ON WED DUE TO THIS. && .AVIATION /19Z THURSDAY THROUGH TUESDAY/...
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LOW PRESSURE WELL OFF THE MID ATLANTIC COAST WILL MOVE TOWARD NOVA SCOTIA THROUGH TONIGHT. ANOTHER OFFSHORE LOW WILL MOVE SLOWLY NORTH UP THE MID ATLANTIC COAST FRIDAY. FROM NYC METRO WEST...BKN-OVC MVFR TO VFR CEILINGS ARE EXPECTED INTO THIS EVENING (3-4 KFT). GENERALLY MVFR EASTERN TERMINALS ON LONG ISLAND AND SRN CT (2-3 KFT). THEN...CEILINGS LOWER LATE THIS EVENING AND OVERNIGHT...MAINLY AFTER MIDNIGHT. MVFR TO IFR EXPECTED...AND THESE IFR CONDITIONS CONTINUE FRIDAY MORNING IN DEVELOPING RAIN. VFR VSBYS FALL TO MVFR AND POSSIBLY IFR LATE TONIGHT AND FRIDAY MORNING. WINDS REMAIN NORTHEAST INTO EARLY EVENING. SPEEDS GENERALLY 10 TO 15 KT WITH OCCASIONAL GUSTS TO AROUND 20 KT. GUSTS SHOULD BECOME LESS FREQUENT AFTER SUNSET...WITH WINDS NORTH/NORTHEAST. WINDS SHOULD INCREASE SLIGHTLY FRIDAY MORNING AS THEY VEER TO THE EAST/NORTHEAST. NY METRO ENHANCED AVIATION WEATHER SUPPORT... DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN BE FOUND AT: HTTP:/WWW.WEATHER.GOV/ZNY/N90 (LOWER CASE) KJFK FCSTER COMMENTS: AMENDMENTS FOR CEILINGS ARE POSSIBLE LATE THIS AFTERNOON/EVENING. CIGS MAY VARY BETWEEN VFR AND MVFR. KLGA FCSTER COMMENTS: AMENDMENTS FOR CEILINGS ARE POSSIBLE LATE THIS AFTERNOON/EVENING. CIGS MAY VARY BETWEEN VFR AND MVFR. KEWR FCSTER COMMENTS: AMENDMENTS FOR CEILINGS ARE POSSIBLE LATE THIS AFTERNOON/EVENING. CIGS MAY VARY BETWEEN VFR AND MVFR...BUT SHOULD REMAIN PREDOMINATELY VFR OR JUST OVER 3 KFT. KTEB FCSTER COMMENTS: AMENDMENTS FOR CEILINGS ARE POSSIBLE LATE THIS AFTERNOON/EVENING. CIGS MAY VARY BETWEEN VFR AND MVFR...BUT SHOULD REMAIN PREDOMINATELY VFR OR JUST OVER 3 KFT. KHPN FCSTER COMMENTS: AMENDMENTS FOR CEILINGS ARE POSSIBLE LATE THIS AFTERNOON/EVENING. CIGS MAY VARY BETWEEN VFR AND MVFR. KISP FCSTER COMMENTS: AMENDMENTS FOR CEILINGS ARE POSSIBLE THIS AFTERNOON/EVENING. GENERALLY EXPECT MVFR CEILINGS ALTHOUGH VFR CEILINGS ARE POSSIBLE LATE THIS AFTERNOON. .OUTLOOK FOR 18Z FRI THROUGH TUE... .FRIDAY AFTERNOON-FRIDAY NIGHT...PERIODS OF RAIN/FOG/LOW CLOUDS WITH MVFR OR LOWER CONDITIONS. NE WINDS G15-20 KT FRIDAY. .SATURDAY-SATURDAY NIGHT...SUB VFR POSSIBLE IN SHOWERS. .SUNDAY AFTERNOON/NIGHT...COLD FRONTAL PASSAGE SHOULD FINALLY BRING AN END TO DISMAL CONDITIONS...WITH CONDITIONS IMPROVING TO VFR AND NW WINDS G20KT. .MON...VFR. W WINDS G25KT POSSIBLE. .TUE...MAINLY VFR ALTHOUGH SUB VFR IN RAIN IS POSSIBLE.
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&& .MARINE... SCA REMAINS IN EFFECT THROUGH FRI NIGHT FOR THE OCEAN...AND THROUGH THIS AFTERNOON FOR ERN LONG ISLAND SOUND...BUT HAS BEEN DROPPED ELSEWHERE. A TIGHTENING PRESSURE GRADIENT AND WELL MIXED BOUNDARY LAYER WILL PRODUCE GUSTS 25-30 KT ON THE OCEAN AND ERN SOUND THIS AFTERNOON...BUT OBS SHOW BLYR MIXING TO BE NOT QUITE AS EFFICIENT ELSEWHERE...SO GUSTS SHOULD REMAIN MOSTLY UNDER 25 KT ON THE WRN SOUND/HARBOR/BAYS. CURRENT FORECAST KEEPS MARGINAL 5-FT SEAS ON THE OCEAN IN THE FORM OF SE-S SWELL THROUGH SAT...BUT THIS REMAINS UNCERTAIN. S FLOW INCREASES SAT NIGHT AHEAD OF AN APPROACHING COLD FRONT... WITH POTENTIAL FOR SCA CONDITIONS ON ALL WATERS BEHIND THE FRONT ON SUNDAY...BEFORE SUBSIDING SUN EVE. SEAS UP TO 5 FT MAY LINGER ON THE EASTERN OCEAN WATERS INTO MON. && .HYDROLOGY... BASIN AVG RAINFALL OF 1/4 TO 1/2 INCH OF RAIN EXPECTED FRI INTO SAT MORNING FOR SE CT AND ERN LONG ISLAND...AND 1/2 TO 2/3 INCH FARTHER WEST FROM LATE TONIGHT INTO SAT MORNING. LOCALLY HIGHER AMOUNTS POSSIBLE IN ANY HEAVIER SHOWERS OR TSTMS. PONDING OF WATER IS POSSIBLE IN AREAS RECEIVING LOCALLY HEAVY RAINFALL. RAINFALL UP TO 1/4 INCH IS POSSIBLE SATURDAY NIGHT INTO SUNDAY WITH A COLD FRONTAL PASSAGE. NO HYDROLOGIC ISSUES ARE EXPECTED. && .TIDES/COASTAL FLOODING... THE HIGHEST SPRING TIDE OF THE YEAR IS APPROACHING WITH THE NEW MOON ON FRIDAY. THE THREAT FOR MINOR TO LOCALLY MODERATE COASTAL FLOODING WILL INCREASE DURING THE EVENING HIGH TIDES THROUGH FRIDAY...AND LIKELY CONTINUE INTO THIS WEEKEND. WATER LEVELS MAY BRIEFLY TOUCH MINOR COASTAL FLOOD LEVELS IN A FEW SOUTH SHORE BAY LOCALES ON SOUTHWESTERN LONG ISLAND WITH THE FRIDAY MORNING HIGH TIDE CYCLE. FOR TONIGHT...ASTRONOMICAL TIDE HEIGHTS WILL BE 1/4-1/2 FT HIGHER THAN THOSE OF LAST NIGHT...WHILE TIDAL DEPARTURES SHOULD BE NEAR TO MAYBE A 1/4 FT HIGHER THAN LAST NIGHT. THIS SHOULD RESULT IN MORE WIDESPREAD MINOR COASTAL FLOODING ALONG THE SOUTH SHORE BAYS OF WESTERN LONG ISLAND/NYC AND WESTERN LONG ISLAND SOUND AND NY HARBOR...WHERE AN ADVISORY HAS BEEN ISSUED. THERE IS POTENTIAL FOR SOME SPOTS ALONG THE BACK BAYS OF SRN NASSAU AND SW SUFFOLK TO HIT MODERATE FLOOD THRESHOLDS THIS EVENING...BUT THE PROBABILITY REMAINS TOO LOW FOR A WARNING AT THIS TIME. MINOR FLOOD LEVELS WILL BE APPROACHED AND POSSIBLY LOCALLY TOUCHED ACROSS THE REMAINING EASTERN COASTAL AREAS. FOR FRI NIGHT...WIDESPREAD MINOR COASTAL FLOODING EXPECTED ONCE AGAIN AS ASTRONOMICAL TIDES PEAK AND SURGE LIKELY REMAINS STEADY. MODERATE COASTAL FLOODING COULD OCCUR ALONG THE SOUTH SHORE BAYS OF WESTERN LONG ISLAND AND QUEENS....WITH ONLY 1 TO 1 1/4 FT SURGE NEEDED IN SPOTS. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...COASTAL FLOOD ADVISORY FROM 9 PM THIS EVENING TO MIDNIGHT EDT TONIGHT FOR CTZ009-010. NY...COASTAL FLOOD ADVISORY FROM 9 PM THIS EVENING TO MIDNIGHT EDT TONIGHT FOR NYZ071-078-177. COASTAL FLOOD ADVISORY FROM 7 PM TO 10 PM EDT THIS EVENING FOR NYZ074-075-080-178-179. NJ...COASTAL FLOOD ADVISORY FROM 7 PM TO 10 PM EDT THIS EVENING FOR NJZ006-106-108. MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ330. SMALL CRAFT ADVISORY UNTIL 6 AM EDT SATURDAY FOR ANZ350-353- 355. && $$ SYNOPSIS...GOODMAN/24/MALOIT NEAR TERM...GOODMAN/MALOIT SHORT TERM...GOODMAN/MALOIT LONG TERM...24 AVIATION...PW MARINE...GOODMAN/24/MALOIT HYDROLOGY...GOODMAN/24/MALOIT TIDES/COASTAL FLOODING...

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