Area Forecast Discussion
Issued by NWS Upton, NY

Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS61 KOKX 300624 AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 224 AM EDT SAT AUG 30 2014 .SYNOPSIS...
-- Changed Discussion --
HIGH PRESSURE SLIDES OFFSHORE SATURDAY INTO SUNDAY. A TROUGH OF LOW PRESSURE SLOWLY APPROACHES FROM THE WEST SUNDAY NIGHT AND MOVES WITHIN THE AREA BY MONDAY. WEAK HIGH PRESSURE BRIEFLY RETURNS BEFORE ANOTHER COLD FRONT APPROACHES TUESDAY. THIS FRONT MOVES ACROSS LATE TUESDAY NIGHT WITH HIGH PRESSURE BUILDING BACK IN FROM THE WEST FROM MID TO LATE NEXT WEEK. ANOTHER COLD FRONT APPROACHES LATE NEXT FRIDAY.
-- End Changed Discussion --
&& .NEAR TERM /THROUGH TODAY/... FORECAST ON TRACK WITH JUST SOME MINOR ADJUSTMENTS TO REFLECT LATEST OBSERVATIONS. OTHERWISE...HIGH PRESSURE CENTERED OVER THE NORTHEASTERN CONUS WILL TRANSLATE EASTWARD TONIGHT...ENDING UP OFFSHORE SATURDAY. THIS WILL ALLOW FOR LIGHT RETURN FLOW TO PRODUCE INCREASING LOW LEVEL MOISTURE. THERE WAS SOME FOG ON THE BACK SIDE OF THE HIGH OVER THE OHIO VALLEY FRIDAY MORNING...SO HAVE INCLUDED PATCHY FOG FOR LATE TONIGHT ACROSS THE OUTLYING AREAS. THE NAM AND GFS TIME HEIGHTS SUGGEST SOME STRATUS DEVELOPS SATURDAY. WITH SIGNIFICANT DRY AIR IN THE MID LEVELS...WILL PREFER A MORE MIXED SCENARIO AND AS A RESULT HAVE GONE WITH A PARTLY CLOUDY FORECAST. LOW RISK OF RIP CURRENTS SATURDAY MORNING THEN INCREASING SOUTHERLY FLOW WILL RESULT IN A MODERATE RISK BY AFTN/EVE. TEMPS A BLEND OF THE GMOS25 AND MET...50/50 DURING THE DAY AND 70/30 MET AT NGT. && .SHORT TERM /TONIGHT/... THE ONSHORE FLOW CONTINUES. THIS SHOULD BE SUFFICIENT FOR AREAS OF STRATUS AND AT LEAST PATCHY FOG DEVELOPMENT. ALL MODELS KEEP SHRTWV ENERGY W OF THE CWA THRU THE PERIOD. AS A RESULT...HAVE KEPT THE FCST DRY DUE TO A LACK OF LIFT. TEMPS A BLEND OF THE GMOS25 AND MET...WEIGHTED TOWARDS THE MET. && .LONG TERM /SUNDAY THROUGH FRIDAY/...
-- Changed Discussion --
LOOKING AT THE LARGE SCALE...THE OVERALL PATTERN IN THE MID LEVELS IS A QUASI-ZONAL FLOW THROUGH THE REMAINDER OF THE FORECAST...SUNDAY THROUGH NEXT FRIDAY. THE GEOPOTENTIAL HEIGHT AT 500MB STAYS MAINLY BETWEEN 582 AND 590DM THROUGHOUT THE PERIOD. THE JET STREAM WILL BE STAYING NORTH OF THE REGION MUCH OF THE TIME AS WELL. ONE DEPARTURE FROM THESE AFOREMENTIONED PARAMETERS IS ON SUNDAY INTO MONDAY. THERE WILL BE A PIECE OF THE JET POSITIONED NORTH OF THE AREA...BUT CLOSE ENOUGH TO PLACE OUR REGION WITHIN THE RIGHT REAR QUAD...ESPECIALLY SUNDAY NIGHT INTO EARLY MONDAY. THIS WILL BE A TIMEFRAME FOR ENHANCED LIFT. LOOKING AT HEIGHT FIELDS...A SMALLER SHORTWAVE...EVIDENT AS A SLIGHT UNDULATION COMPARED TO THE OVERALL PATTERN...MOVES NEAR SUNDAY AND EAST OF THE AREA ON MONDAY. AT THE SURFACE...HIGH PRESSURE WILL BE DISPLACED WELL OFFSHORE STARTING ON SUNDAY. THEN A TROUGH OF LOW PRES WILL BE SLOWLY APPROACHING FROM THE WEST. IT WILL BE LOSING STRENGTH WITH TIME AS IT MOVES IN...WITHOUT A STRONG PARENT LOW ASSOCIATED WITH IT AND THE SLIGHT AMPLIFICATIONS OF HEIGHT FIELDS ALOFT. THE TROUGH MOVES IN MONDAY AND WEAKENS WITHOUT A REAL SIGNIFICANT CHANGE OF WIND DIRECTION. WE WILL STILL HAVE OFFSHORE HIGH PRESSURE...NOT TOO STRONG OVER THE LOCAL REGION. SO THE AREA WILL BE SUSCEPTIBLE TO DIURNALLY INDUCED CONVECTION. A LITTLE STRONGER PARENT LOW IN SOUTHEAST CANADA NEAR THE GREAT LAKES MOVES INTO THE NORTHEAST TUESDAY NIGHT WITH AN ASSOCIATED COLD FRONT MOVING IN OVERNIGHT INTO WEDNESDAY MORNING. THE FRONT PUSHES EAST OF THE REGION WEDNESDAY WITH A WEAK HIGH BUILDING IN FROM THE WEST THEREAFTER THROUGH EARLY FRIDAY. ANOTHER FRONT MAY APPROACH FOR LATER NEXT FRIDAY.` IN TERMS OF WEATHER...INCREASING CHANCES OF SHOWERS AND THUNDERSTORMS SUNDAY...CONTINUING THROUGH MONDAY. CONVECTION TAPERS DOWN MONDAY NIGHT BEFORE ANOTHER CHANCE TUESDAY AFTERNOON THROUGH TUESDAY NIGHT. IN TERMS OF THUNDERSTORM CHARACTERISTICS...30-35 KT BULK 0-6KM SHEAR FOR SUNDAY CONVEYED BY FORECAST MODELS. MODELS FORECAST MUCAPE OF 1000-2000 J/KG SUNDAY AND MONDAY WITH DAYTIME HEATING. LESS SHEAR MONDAY BUT NEARLY THE SAME MUCAPE DEVELOPMENT. A REMARKABLE WARMING TREND SETTING UP FOR THE END OF THE WEEKEND INTO THE NEW WEEK. TEMPERATURES AVERAGING ABOVE NORMAL. FOR HIGHS...AROUND 4-7 DEGREES ABOVE NORMAL WITH VALUES WELL INTO THE 80S FOR THE LONG TERM PERIOD. LOWS GENERALLY 5-10 DEGREES ABOVE NORMAL SUNDAY NIGHT THROUGH TUESDAY NIGHT AND A FEW DEGREES ABOVE NORMAL WEDNESDAY NIGHT THROUGH THURSDAY NIGHT.
-- End Changed Discussion --
&& .AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
-- Changed Discussion --
HIGH PRES OFF THE NEW ENGLAND COAST WILL MOVE OUT TO SEA THROUGH TONIGHT AS A TROUGH OF LOW PRES APPROACHES FROM THE WEST. TOUGH FORECAST INTO THE MORNING. MVFR CONDS ARE POSSIBLE...BUT SOME OF THE MODEL GUIDANCE IS NOT INDICATING THIS. HAVE MAINTAINED THE FEW-SCT MENTION OF LOW CLOUDS WITH THE EXCEPTION OF KISP FOR NOW WHERE A TEMPO HAS BEEN ADDED BETWEEN 12Z AND 15Z. 09Z TAFS WILL ADDRESS FURTHER...BUT 06Z OBS CAME IN WITH FEW-SCT CLOUDS AROUND 3K FT (BKN AT KJFK) SO MAY NEED TO AMEND SOONER. HAVE ALSO MAINTAINED TEMPO FOR MVFR VIS AT KGON/KSWF AFT 08Z. S WINDS INCREASE AFT 12Z. GUSTS UP TO 20KT POSSIBLE AFT 16Z...BUT NOT CONFIDENT ON THIS JUST YET. WILL ALSO ADDRESS FURTHER IN 09Z TAFS. MVFR CIGS/BR POSSIBLE AGAIN TONIGHT...BUT PCPN SHOULD HOLD OFF TILL SUNDAY MORNING. .OUTLOOK FOR 06Z SUN THROUGH THU... .SAT NIGHT-TUE NIGHT...MAINLY MVFR CIGS AND VSBY WITH MULTIPLE ROUNDS OF SHOWERS AND TSTMS STARTING DURING THE DAY SUNDAY. .WED-THU...MAINLY VFR.
-- End Changed Discussion --
&& .MARINE... WINDS AND WAVES BLW SCA LVLS THRU SAT NGT. WITH INCREASING SOUTHERLY FETCH SUNDAY AND SUNDAY NIGHT...SCA CONDITIONS MAINLY FOR SEAS ARE FORECAST AS SEAS ARE FORECAST TO REACH 5 FT ON THE OCEAN. WIND GUSTS WILL BE LIMITED TO AROUND 20 KT. HOWEVER...PRESSURE GRADIENT WILL WEAKEN AGAIN FOR NEXT WEEK SO CONDITIONS ARE FORECAST TO RETURN TO SUB SCA LEVELS BY LATER MONDAY MORNING AND THEREAFTER. && .HYDROLOGY... NO RAINFALL THROUGH SAT. LAYER PW OF AROUND 2 INCHES WITH FRONT APPROACHING SUNDAY AND INTO THE REGION SUNDAY NIGHT AND MONDAY...SO ANY SHOWERS AND THUNDERSTORMS WILL BE CAPABLE OF PRODUCING LOCAL HEAVY DOWNPOURS. LOCALIZED FLOODING THREAT WILL REMAIN WHICH WOULD VARY FROM MINOR AND POOR DRAINAGE TO POSSIBLY FLASH FLOODING. ANY FLASH FLOODING IS EXPECTED TO BE ISOLATED. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...NONE. && $$

USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.