Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 041940 AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 340 PM EDT TUE AUG 4 2015 .SYNOPSIS... A COLD FRONT WILL SLOWLY PASS THROUGH THE REGION TONIGHT...PUSHING OFFSHORE EARLY WEDNESDAY. WEAK HIGH PRESSURE BUILDS INTO THE AREA ON THURSDAY. LOW PRESSURE MAY IMPACT THE AREA FRIDAY INTO SATURDAY. HIGH PRESSURE RETURNS FOR THE SECOND HALF OF THE WEEKEND. A FRONTAL SYSTEM APPROACHES AND AFFECTS THE AREA FOR THE BEGINNING OF NEXT WEEK. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... TSTMS CONTINUE N OF THE CWA WHERE THERE IS SOME UPR SUPPORT. ACROSS THE CWA...SUBSIDENCE STILL LIMITING INITIATION. LAPS AT 19Z HAS ABOUT 2500 J/KG SBCAPE ON LI...WITH ABOUT 1000-2000 REMAINDER OF THE AREA BASICALLY E OF THE HUDSON. CIN IS MINIMAL. CU FIELD ON STLT BUT VERTICAL EXTENT LIMITED ACROSS THE CWA. ANY FOCUS IN THIS MDT CAPE ENVIRONMENT COULD ALLOW ISOLD CELLS TO BLOSSOM. WITH 40-50KT 0-6KM SHEAR...SVR POTENTIAL WITH ANY TSTMS. AS A RESULT...MAINTAINED ISOLD TSTMS IN THE FCST THRU EARLY THIS EVE FOR THE ERN 2/3 OF THE CWA. BY THE TIME THERE IS A LITTLE MID LVL LIFT TNGT...THE AREA IS MAINLY STABLE AND CAPPED. EXCEPTION IS EXTREME ERN LI PER THE NAM WHERE THE CHC FOR ISOLD TSTM DEVELOPMENT LINGERS LATER INTO THE EVE. A BLEND OF GUIDANCE WAS USED FOR TEMPS...BUT LIMITED THE RADIATIONAL COOLING SIGNATURE ACROSS THE PINE BARRENS OF LI WITH THE BOUNDARY IN THE VICINITY. HIGH RISK FOR RIPS CONTINUES THIS EVE WITH MANY REPORTS OF DANGEROUS RIPS. A RIP CURRENT STATEMENT IS IN EFFECT. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/... UPR JET DIVES INTO THE AREA BY AFTN. DESPITE LIMITED INSTABILITY...THE NAM IS PICKING UP ON SCT-ISOLD CONVECTION INTO THE EARLY EVE. THE GFS IS DRY. LAPSE RATES ARE SLIGHTLY STEEPER IN THE NAM...WITH AROUND 8C BETWEEN H85-H7. THE GFS IS AROUND 7C IN THE SAME LAYER. WITH THE APPROACHING COLD POOL ALOFT...JET AND WARM SST/S...DID NOT DISCOUNT THE NAM AND HAVE THEREFORE INCLUDED 20 POPS FOR DIURNAL ACTIVITY. ISOLD LIGHTNING STRIKES TODAY INVOF LAKES HURON AND ONTARIO LEND SOME SUPPORT TO TSTMS CHCS. TEMPS A BLEND OF THE GUIDANCE WHICH WAS IN GOOD AGREEMENT. && .LONG TERM /THURSDAY THROUGH TUESDAY/... UPPER LEVEL LOW OVER SOUTHEASTERN CANADA WILL PUSH EAST ON THURSDAY...ALLOWING FOR ZONAL FLOW TO DEVELOP ALOFT. SURFACE HIGH PRESSURE BUILDS IN AT THE SURFACE KEEPING THE AREA DRY. COMPLICATED FORECAST THEREAFTER IN REGARDS TO THE POTENTIAL FOR LOW PRESSURE IMPACTING THE AREA MAINLY FROM LATE THURSDAY NIGHT THROUGH AT LEAST SATURDAY. THIS STORM WILL FORM FROM A SHORTWAVE CURRENTLY OVER THE ROCKIES WHICH WILL EJECT OUT INTO THE MID-WEST WEDNESDAY NIGHT INTO THURSDAY MORNING. THIS WILL ALLOW A WEAK SURFACE LOW TO DEVELOP. THE TRACK OF THIS LOW THEREAFTER IS VERY UNCERTAIN. 12Z NAM AND THE 00Z ECMWF SHARE A SIMILAR TRACK...BRINGING THE LOW OVER THE OHIO VALLEY OVERNIGHT THURSDAY...OVER THE MID-ATLANTIC ON FRIDAY AND OFF THE EAST COAST FRIDAY NIGHT INTO SATURDAY MORNING. THEREAFTER...THE ECMWF PASSES SOUTH AND EAST LONG ISLAND SATURDAY. THE 12Z GFS AND THE CANADIAN TAKE THE LOW OVER FARTHER SOUTH...OVER VIRGINIA/NORTH CAROLINA...THEN TURNING NORTHEAST AND PASSING WELL SOUTH AND EAST OF THE AREA...HUNDREDS OF MILES EAST OF THE 40/70 BENCHMARK...AND THUS HAVING NO IMPACT TO THE AREA WHATSOEVER. THE 00Z ECMWF ENSEMBLE MEAN FOLLOWS A SIMILAR TRACK TO THE OPERATIONAL...BUT THERE IS A GOOD DEAL OF SPREAD AND THUS UNCERTAINTY WITH THE LOW AS IT EJECTS OUT OF THE ROCKIES. THEREFORE...EXPECT A GOOD DEAL OF DIFFERENCES IN MODELS SOLUTIONS UNTIL THIS FEATURE MOVES OUT OF THE ROCKIES. GIVEN THE UNCERTAINTY...WILL NOT MAKE MUCH IN THE WAY OF CHANGES WITH WHAT IS CURRENTLY IN THE FORECAST. ANOTHER CONCERN IS THE NEW 12Z ECMWF HAS SHIFTED FARTHER SOUTH THAN THE PREVIOUS RUN...COMING MORE IN LINE WITH THE GFS AND CANADIAN...MAKING THE NAM MORE OF AN OUTLIER. IF THIS TREND CONTINUES WITH THE MODELS...THERE WOULD BE MUCH LESS IN THE WAY OF RAINFALL. && .AVIATION /19Z TUESDAY THROUGH SUNDAY/... A COLD FRONT WILL MOVE EAST ACROSS THE AREA TONIGHT FOLLOWED BY HIGH PRESSURE ON WEDNESDAY. VFR WEATHER CONDITIONS WILL PREVAIL THROUGH WEDNESDAY. CHANCE OF ISOLATED TSTMS WITH STRONG WIND GUSTS...MAINLY EAST OF NYC THROUGH SUNSET. SEA BREEZES WILL INCREASE SW WINDS TO ARND 15 KT WITH GUSTS TO 25 KT UNTIL SUNSET ACROSS ATLANTIC COASTAL TERMINALS INCLUDING KJFK. WINDS BECOME LIGHT AND VARIABLE AFT SUNSET THEN SHIFT FROM THE W ARND 10 KT ON WED. ...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: AMENDMENTS MAY BE NEEDED FOR ISOLATED TSTMS UNTIL SUNSET. KLGA FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED FOR ISOLATED TSTMS UNTIL SUNSET. KEWR FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED FOR ISOLATED TSTMS UNTIL SUNSET. KTEB FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED FOR ISOLATED TSTMS UNTIL SUNSET. KHPN FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED FOR ISOLATED TSTMS UNTIL SUNSET. KISP FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED FOR ISOLATED TSTMS UNTIL SUNSET. .OUTLOOK FOR 18Z WED THROUGH SUN... .WED AFTN-THU...VFR. GENERALLY W FLOW. .FRI...CHANCE MVFR OR LOWER IN RAIN. WINDS BECOMING NE. .SAT...CHANCE OF MVFR OR LOWER POSSIBLE IN RAIN. NE WINDS. .SUN...VFR. && .MARINE... SEAS STILL IN THE 4-6FT RANGE ON THE OCEAN. HAVE EXTENDED THE SCA THRU TNGT BASED ON THESE OBS AND THE 12Z WAVEWATCH. ELSEWHERE...GUSTS MAINLY IN THE LWR 20S EXPECTED THRU THIS EVE. AN OCNL NEAR SHORE GUST TO 25KT POSSIBLE S SHORE BAYS AND HARBOR TIL SUNSET. WINDS AND SEAS SUBSIDE TO BLW SCA LVLS ALL WATERS WED AND WED NGT. WEAK HIGH PRESSURE WILL MOVE OVER THE WATERS ON THURSDAY WITH LOW PRESSURE ON FRIDAY INTO SATURDAY. SUB SCA CONDITIONS ARE EXPECTED THURSDAY INTO FRIDAY...WITH SEAS BUILDING TO AROUND 5 FT ON THE OCEAN SATURDAY INTO SATURDAY NIGHT WITH THE APPROACH OF THE LOW. SEAS SUBSIDE SUNDAY AS THE LOW PUSHES AWAY FROM THE AREA. && .HYDROLOGY... ORGANIZED SIGNIFICANT RAINFALL IS NOT EXPECTED THROUGH THURSDAY. A WIDESPREAD SIGNIFICANT RAINFALL IS POSSIBLE LATE THURSDAY INTO FRIDAY. HOWEVER...UNCERTAINTY EXISTS IN WHERE AND WHEN THE HEAVIEST OF THE RAIN WILL FALL. ANTECEDENT DRY CONDITIONS SHOULD LIMIT FLOODING POTENTIAL. HOWEVER...ANY HEAVIER RAINFALL THAT DOES DEVELOP WOULD HAVE THE POTENTIAL FOR LOCALIZED FLOODING. && .EQUIPMENT... TEWR TERMINAL DOPPLER RADAR REMAINS UNAVAILABLE. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...HIGH RIP CURRENT RISK UNTIL 9 PM EDT THIS EVENING FOR NYZ075- 080-081-178-179. NJ...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT WEDNESDAY FOR ANZ350-353- 355. && $$ SYNOPSIS...JMC/JP NEAR TERM...JMC SHORT TERM...JMC LONG TERM...JP AVIATION...GC MARINE...JMC/JP HYDROLOGY...JMC/JP EQUIPMENT...

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