Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 101954 AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 354 PM EDT THU JUL 10 2014 .SYNOPSIS... A COLD FRONT REMAINS STALLED TO THE SOUTH OF LONG ISLAND THROUGH TONIGHT...EVENTUALLY PUSHING TO THE SOUTH AND EAST AS HIGH PRESSURE BUILDS IN FROM THE WEST TOMORROW INTO THE WEEKEND. THE REGION REMAINS ON THE BACKSIDE OF THE BERMUDA HIGH THROUGH SATURDAY NIGHT. A WARM FRONT LIFTS TO THE NORTH SUNDAY. A COLD FRONT THEN SLOWLY APPROACHES FROM THE WEST EARLY NEXT WEEK...THEN SLOWLY CROSSES THE AREA AND MOVES TO OUR EAST DURING THE MIDDLE OF NEXT WEEK. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... COLD FRONT LINGERS JUST SOUTH OF LONG ISLAND THROUGH THE FIRST PART OF TONIGHT BEFORE FINALLY PUSHING OFF TO THE SOUTH AND EAST...ALLOWING FOR HIGH PRESSURE TO BUILD IN FROM THE GREAT LAKES. DIURNALLY DRIVEN CONVECTION ON GOING AS OF LATE THIS AFTN TO THE SOUTH AND WEST...AND MAY LINGER THROUGH EARLY THIS EVENING AS TRIGGERING SHORTWAVE WORKS THROUGH DELMARVA NORTH THROUGH THE TRI STATE AREA. BEST CHC FOR ANY PCPN LOOKS TO BE TO THE WEST OF NYC METRO WHERE PARTLY CLOUDY SKIES HAVE ALLOWED THE MOST WARMING OF TEMPS...AND THUS WHERE HIGHER INSTABILITY VALUES (ABOUT 500 J/KG) EXIST. COVERAGE DIMINISHES WITH THE LOSS OF DAYTIME HEATING SO WILL TAPER POPS OFF NORTH AND WEST OF NYC METRO BY 03Z. A WEAK LOW RIDES THE FRONT OVERNIGHT...WITH MINIMAL FORCING ALOFT FROM A PASSING VORT MAX...SO MAINTAINED LOWER END POPS FOR MOSTLY THE WATERS THROUGH EARLY MORNING. A STRAY SHOWER COULD MAKE IT TO LONG ISLAND...BUT OVERALL CONFIDENCE LEANS MORE TO A DRY FORECAST FOR THE AREA FOR THE MAJORITY OF THE NIGHT. MOSTLY CLOUDY CONDITIONS WILL PERSIST BUT SLIGHTLY COOLER TEMPS OVER THE AREA WOULD LEND TO OVERNIGHT LOWS RIGHT AT NORMAL...JUST A TAD COOLER THAN LAST NIGHT. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/... COLD FRONT FINALLY CLEARS THE REGION WITH HIGH PRESSURE BUILDING IN FROM THE WEST. REGION REMAINS ANOTHER DAY UNDER TROUGHING ALOFT. OVERALL...EXPECTING DRY CONDITIONS FOR THE AREA. THERE IS SOME INDICATIONS THAT A PASSING SHORTWAVE IN THE AFTN COULD TRIGGER AN ISO DIURNAL SHOWER OR TSTM OVER MAINLY INTERIOR REGIONS WHERE THERE WILL BE BETTER HEATING/INSTABILITY SO WILL KEEP THE INCLUSION OF SLIGHT CHC POPS. WILL ADMIT THAT MOISTURE WILL BE LIMITED AND THIS COULD EXCLUDE THE DEVELOPMENT DESPITE ANY FORCING. MOST OF THE AREA WILL SEE ONLY PARTLY CLOUDY SKIES. ANY PCPN THREAT DIMINISHES QUICKLY TOMORROW EVENING WITH LOSS OF HEATING. ZONAL FLOW SLOWLY BUILDING IN ALOFT WITH THE HIGH PRESSURE AT THE SURFACE WILL KEEP DRY CONDITIONS AND RESULT IN CLEARING SKIES. DEPENDING ON HOW QUICKLY THE MOISTURE RETURNS...COULD SEE PATCHY FOG EARLY SAT MORNING. TEMPS HOVERING RIGHT AROUND NORMAL THROUGH FRIDAY NIGHT. && .LONG TERM /SATURDAY THROUGH THURSDAY/... WEAK RIDGING/ZONAL FLOW SETS UP ON SATURDAY...WHICH COUPLED WITH STABILIZING ONSHORE FLOW SHOULD KEEP THINGS DRY. FOR HIGHS SATURDAY USED A BLEND OF MIXING DOWN FROM950-850 HPA PER BUFKIT SOUNDINGS WITH NAM 2-METER TEMPERATURES AND MAV/MET GUIDANCE - WITH HIGHS FORECAST TO BE AROUND NORMAL. 700-500 HPA SHORTWAVE TROUGH APPROACHES SATURDAY NIGHT...SHOULD SEE INCREASE IN MID/HIGH CLOUDS AS A RESULT...FOR NOW THINK ANY SHRA/TSRA WILL HOLD OFF ACROSS FAR NW/ZONES UNTIL AFTER 10Z...SO WENT WITH A DRY FORECAST. USED A BLEND OF MAV/MET GUIDANCE WITH NAM 2-METER TEMPERATURES FOR LOWS SATURDAY NIGHT...VALUES SHOULD BE NEAR NORMAL. COMBINATION OF 700-500 HPA SHORTWAVE TROUGH LIFTING THROUGH TO THE NE AND PASSING OF RELATIVELY WEAK SURFACE WARM FRONT TO THE NORTH SUNDAY...WARRANTS CHANCE POPS FOR SHRA/TSTMS - EXCEPT SLIGHT CHANCE PORTIONS OF FAR SE ZONES - MAINLY IN THE AFTERNOON. GIVEN LIMITED INSTABILITY AND LACK OF JET FORCING...NOT ANTICIPATING ANY STRONG OR SEVERE STORMS AT THIS TIME. FOR HIGHS SUNDAY USED A BLEND OF MEX/MEN/EKD/ECE/ECM/WPC GUIDANCE WITH NAM 2-METER TEMPERATURES AND A MIX DOWN FROM 975-900 HPA PER BUFKIT SOUNDINGS. HIGHS SHOULD BE SLIGHTLY BELOW NORMAL. THE REGION WILL BE UNDER SW FLOW ALOFT SUNDAY NIGHT-WEDNESDAY AS A CLOSED LOW SLOWLY WORKS ITS WAY ACROSS THE GREAT LAKES. THE WEATHER WILL BE QUITE UNSETTLED IN THIS TIME FRAME WITH MULTIPLE SHORTWAVES EMBEDDED IN THE FLOW...AND AN APPROACHING THEN PASSING COLD FRONT. FOR NOW HAVE CAPPED POPS AT HIGH END CHANCE...AS TIMING OF INDIVIDUAL SHORTWAVES IS PROBLEMATIC THIS TIME OUT...PLUS MODELS HANDLING OF CLOSED LOWS CAN BE SUSPECT AT TIMES THIS FAR OUT...ESPECIALLY NOTING THIS IS AN ACLIMATOLOGICAL PATTERN FOR THIS TIME OF YEAR. GIVEN GENERALLY IN WARM SECTOR - HAVE GONE WITH A CHANCE OF SHRA/TSTMS SUNDAY NIGHT-TUESDAY NIGHT THEN SLIGHT CHANCE POPS WEDNESDAY (REFLECTING UNCERTAINTY IN FRONTAL TIMING). IT APPEARS THERE COULD BE ENOUGH AFTERNOON/EVENING INSTABILITY TO SUPPORT SOME STRONGER CONVECTION IN THAT TIME FRAME AHEAD OF THE COLD FRONT. REFER TO THE HYDROLOGY SECTION OF THE AFD FOR INITIAL THOUGHTS ON POTENTIAL FOR SIGNIFICANT RAINFALL AND ANY IMPACTS. FOR NOW IT APPEARS THE COLD FRONT EXITS TO THE EAST BY WEDNESDAY NIGHT CLOSED LOW ALOFT BUILDS INTO THE NE INTO THURSDAY. FOR NOW...HAVE GONE WITH A DRY FORECAST WEDNESDAY NIGHT/THURSDAY. HOWEVER...DEPENDING ON THE EXACT TRACK OF THE CLOSED LOW...THERE COULD BE SOME INSTABILITY SHRA/TSTMS THURSDAY ASSOCIATED WITH ITS COLD POOL. TOO MUCH UNCERTAINTY TO PLACE THIS IN THE FORECAST AT THIS TIME. FOR TEMPERATURES SUNDAY NIGHT-THURSDAY USED A BLEND OF MEX/MEN/EKD/ECE/ECM/WPC GUIDANCE. TEMPERATURES START OUT ABOVE NORMAL...THEN TREND TO BELOW NORMAL BY THE MIDDLE OF NEXT WEEK. QUITE OF BIT OF UNCERTAINTY ON TEMPERATURES FROM AROUND TUESDAY ON AS IT DEPENDS ON EXACT TRACK/EVOLUTION OF CLOSED UPPER LOW. && .AVIATION /20Z THURSDAY THROUGH TUESDAY/... COLD FRONT REMAINS JUST OFFSHORE AS HIGH PRES BUILDS OVER THE GREAT LAKES AND OHIO VALLEY AND PUSHES TO THE EAST. VFR. CANNOT RULE OUT AN ISOLATED TSTM OR 2 THIS EVENING...BUT COVERAGE WOULD BE CONFINED TO AREAS WEST OF THE HUDSON RIVER. WITH CONFIDENCE SO LOW...WILL NOT MENTION IN THE TAFS. SOME STRATUS MAY DEVELOP AFTER MIDNIGHT TONIGHT...POSSIBLY RESULTING IN MVFR/IFR CIGS. FOR NOW...WILL CAP AT FEW008 FOR MANY OF THE COASTAL TERMINALS...BUT DO NOT THINK THERE WILL BE ENOUGH LOW-LEVEL MOISTURE FOR WIDESPREAD STRATUS. SEA BREEZES WILL TURN WINDS TO A S/SE FLOW THROUGH THIS EVENING BEFORE GOING L/V TONIGHT. FRIDAY WILL ONCE AGAIN FEATURE NE WINDS INITIALLY...TURNING S/SE BEHIND AFTERNOON SEA BREEZES. WINDS SPEEDS GENERALLY 10 KT OR LESS THROUGH THE PERIOD. ...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: AFTERNOON SEA BREEZE COULD BE MORE SOUTHERLY THAN FCST. KLGA FCSTER COMMENTS: LATE DAY OCEAN SEA BREEZE COULD BE MORE SOUTHERLY THAN FCST. KEWR FCSTER COMMENTS: HIGH CONFIDENCE. KTEB FCSTER COMMENTS: HIGH CONFIDENCE. KHPN FCSTER COMMENTS: HIGH CONFIDENCE. KISP FCSTER COMMENTS: AFTERNOON SEA BREEZE COULD BE MORE SOUTHERLY THAN FCST. .OUTLOOK FOR 20Z FRIDAY THROUGH TUESDAY... .FRIDAY...VFR. .FRIDAY NIGHT-SUNDAY MORNING...LOW STRATUS/FOG WITH MVFR OR LOWER CONDS POSSIBLE EACH LATE NIGHT AND EARLY MORNING. OTHERWISE VFR. .SUNDAY AFTERNOON-TUESDAY...SCT SHOWERS/TSTMS WITH LOCAL MVFR OR LOWER CONDS AND GUSTY WINDS. && .MARINE... HIGH PRESSURE BUILDING IN WILL RESULT IN WINDS AND SEAS REMAINING BELOW SCA LEVELS TONIGHT THROUGH SUNDAY. HOWEVER PERSISTENT SOUTHERLY FLOW...COUPLED WITH A POSSIBLE SOUTHERLY SWELL COULD PRODUCE WAVES TO SMALL CRAFT LEVELS OVER MAINLY EASTERN COASTAL WATERS MONDAY AND TUESDAY. && .HYDROLOGY... NO WIDESPREAD SIGNIFICANT HYDROLOGIC ISSUES EXPECTED THROUGH THE WEEKEND. THERE IS THE POTENTIAL FOR SIGNIFICANT RAINFALL - WIDESPREAD 1/2 INCH OR MORE - FROM LATE SUNDAY INTO WEDNESDAY AS PRECIPITABLE WATERS COULD REACH AROUND 2 INCHES FOR AN EXTENDED PERIOD OF TIME - FAVORING AT LEAST LOCALLY HEAVY RAINFALL. AT THIS TIME THERE IS TOO MUCH UNCERTAINTY TO SPECIFY EXACT AMOUNTS OR SPECIFIC THREATS...OTHER THAN TO NOTE THE POTENTIAL FOR MINOR URBAN/POOR DRAINAGE FLOODING AND POSSIBLY LOCALIZED FLOODING IN AREAS THAT EXPERIENCE LOCALLY HEAVY RAINFALL. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...NONE. && $$ SYNOPSIS...MALOIT/SEARS NEAR TERM...SEARS SHORT TERM...SEARS LONG TERM...MALOIT AVIATION...MPS MARINE...MALOIT/SEARS HYDROLOGY...MALOIT/SEARS

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