Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 221749 AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 149 PM EDT FRI AUG 22 2014 .SYNOPSIS... MULTIPLE UPPER LEVEL DISTURBANCES CROSS THE TRI-STATE THROUGH SATURDAY...AS HIGH PRESSURE BUILDS DOWN FROM SOUTHEASTERN CANADA. THIS HIGH CONTINUES TO BUILD OVER THE AREA EARLY NEXT WEEK...THEN PASSES EAST BY MID TO LATE WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 17Z WATER VAPOR IMAGERY INDICATING MID LVL SHORTWAVE/ASSOCIATED WEAK VORT MAX MOVING THROUGH CENTRAL NY. FORCING WITH THIS WAVE IS FAIRLY WEAK...JUST WORKING TO TRIGGER SCT CONVECTION OVER THE INTERIOR REGIONS. FLOW ALOFT WEAK YET AGAIN TODAY SO ANY SHOWER THAT DOES FORM COULD RESULT IN A BRIEF HEAVY RAINFALL. CONTINUED CHC POPS WELL NORTH/WEST OF NYC METRO. ONSHORE ALONG THE COAST KEEPING A MORE STABLE AIRMASS IN PLACE...SO WENT SLIGHT CHC RIGHT AROUND THE CITY...THEN DRY TO THE EAST. ISO TSTM PSBL WELL INLAND...BUT LOWER END THREAT WITH THE THINKING IT WILL BE MORE JUST SHOWER ACTIVITY. BKN-OVC SKY COVER PERSISTING...AND COMBINING WITH THE EASTERLY FLOW...SEEING TEMPS A FEW DEGREES BELOW NORMAL...GENERALLY IN THE 70S. && .SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/... 700-500 HPA TROUGH AXIS APPROACHES TONIGHT...THEN PUSHES TO THE S SATURDAY. DO RESTRICT POPS THIS EVENING MAINLY TO THE NW 1/2 OF THE CWA...AND MENTION OF THUNDER TO THE SW 1/2 OF THE CWA - AS THIS IS THE ONLY AREA WHERE HAVE ANY FORECAST INSTABILITY - ONCE AGAIN MAINLY ALOFT. PRECIPITATION CHANCE FALL OFF FAIRLY RAPIDLY AFTER MIDNIGHT FRIDAY NIGHT. NOTE THE ECMWF IS THE ONLY MODEL SHOWING ANY PRECIPITATION LATE FRIDAY NIGHT/SATURDAY MORNING SO HAVE DISCARDED AS AN OUTLIER FOR NOW. DO EXPECT SHRA TO RETURN MAINLY ACROSS THE NORTHERN TIER SATURDAY AFTERNOON AHEAD OF THE FINAL VORTICITY LOBE RIGHT IN THE WAKE OF THE 700-500 HPA TROUGH AXIS. FOR LOWS TONIGHT USED A BLEND OF MAV/MET GUIDANCE WITH NAM 2-METER TEMPERATURES...WITH ONCE AGAIN ABUNDANT CLOUD COVER EXPECTED. LOWS SHOULD BE NEAR TO SLIGHTLY ABOVE NORMAL. FOR HIGHS SATURDAY...WITH THE POTENTIAL FOR SOME SUNSHINE IN THE LATE AFTERNOON...USED A BLEND OF MIXING DOWN FROM 875 HPA WITH NAM 2-METER TEMPERATURES AND A BLEND OF MAV/MET GUIDANCE. HIGHS SHOULD BE AROUND 5 DEGREES BELOW NORMAL. EVEN WITH NE LOW LEVEL FLOW...WILL SEE GRADUAL CLEARING FROM SATURDAY NIGHT THROUGH THE REMAINDER OF THE WEEKEND AS DEEP LAYERED RIDGING BUILDS OVER THE AREA AND SURFACE HIGH PRESSURE BUILDS DOWN FROM SE CANADA. EXPECT THIS TIME FRAME TO BE DRY AS A RESULT. LOWS SATURDAY NIGHT WERE BASED ON A BLEND OF MAV/MET GUIDANCE WITH NAM 2-METER TEMPERATURES...AND SHOULD BE NEAR TO SLIGHTLY BELOW NORMAL. FOR HIGHS SUNDAY USED A BLEND OF MAV/MET GUIDANCE WITH NAM 2-METER TEMPERATURES AND A MIX DOWN FROM 875 HPA PER BUFKIT SOUNDINGS. THIS YIELDS VALUES A COUPLE OF DEGREES BELOW NORMAL. FOR LOWS SUNDAY NIGHT USED A BLEND OF MEX/MEN/EKD/ECE/ECM/WPC GUIDANCE WITH NAM 2-METERS. EXPECT LOWS TO BE AROUND 5 DEGREES BELOW NORMAL. && .LONG TERM /MONDAY THROUGH THURSDAY/... AMPLIFIED PATTERN EARLY ON WITH LARGE RIDGE BUILDING THROUGH TUESDAY BEFORE FLATTENING AND GIVING WAY TO UPSTREAM TROUGH LATER WEDNESDAY AND THURSDAY. SURFACE HIGH PRESSURE OVER THE AREA SLOWLY DRIFTS OFFSHORE TUESDAY AND WEDNESDAY...AS A COLD FRONT APPROACHES THURSDAY FROM THE WEST. EXPECT DRY AND SEASONABLE CONDITIONS THROUGH THE MIDDLE OF NEXT WEEK COURTESY OF THE RIDGE. TEMPS SLOWLY MODIFY FROM SLIGHTLY BELOW NORMAL MONDAY...TO NEAR OR EVEN ABOVE NORMAL BY MID WEEK. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... HIGH PRESSURE SLOWLY BUILDS SOUTHWARD INTO THE REGION THROUGH THE TAF PERIOD. CONDITIONS VARY BETWEEN MAINLY VFR TO LOCALIZED MVFR TRANSITION TO MOSTLY MVFR TONIGHT. LATE TONIGHT INTO EARLY SATURDAY MORNING...CIGS COULD POSSIBLY LOWER AT TIMES BETWEEN 1K-1.5KFT. SHOWER ACTIVITY CONFINED TO NEAR KSWF. GENERALLY FLOW AROUND 070 TO 110 DEGREES AROUND 8-10 KT. KLGA MORE NE FLOW UNTIL LATE THIS AFTERNOON. 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: THERE IS A CHANCE CIGS COULD LOWER TO MVFR BETWEEN 2K-3KFT BEFORE 02Z. KLGA FCSTER COMMENTS: THERE IS A CHANCE CIGS COULD LOWER TO MVFR BETWEEN 2K-3KFT BEFORE 02Z. NE FLOW COULD LAST 1 HOUR LATER THAN INDICATED IN TAF BEFORE SWITCHING TO MORE E FLOW. KEWR FCSTER COMMENTS: THERE IS A CHANCE CIGS COULD LOWER TO MVFR BETWEEN 2K-3KFT BEFORE 02Z. KTEB FCSTER COMMENTS: THERE IS A CHANCE CIGS COULD LOWER TO MVFR BETWEEN 2K-3KFT BEFORE 02Z. KHPN FCSTER COMMENTS: THERE IS A CHANCE CIGS COULD LOWER TO MVFR BETWEEN 2K-3KFT BEFORE 02Z. KISP FCSTER COMMENTS: THERE IS A CHANCE CIGS COULD LOWER TO MVFR BETWEEN 2K-3KFT BEFORE 02Z. .OUTLOOK FOR 18Z SAT THROUGH WED... .SAT...BECOMING VFR WITH ENE FLOW. .SUN-WED...VFR. && .MARINE... WINDS AND SEAS FORECAST APPEARS ON TRACK FOR TODAY. FOR NOW FORECASTING SUB-SCA CONDITIONS ON ALL WATERS THROUGH SUNDAY NIGHT. HOWEVER A PERSISTENT E-NE FLOW OF 10-15KT WITH GUSTS UP TO 20 KT FROM TONIGHT INTO SUNDAY NIGHT OVER THE COASTAL OCEAN WATERS COULD POSSIBLY BUILDS SEAS TO AT LEAST 5 FT BY LATE SATURDAY. HOWEVER...LATEST WAVEWATCH III GUIDANCE SHOWS SEAS ONLY REACHING 4 FT...SO HAVE FORECASTED ACCORDINGLY FOR NOW BUT CANNOT RULE OUT SEAS ULTIMATELY BEING 1-2 FT HIGHER THAN THIS OVER THE COASTAL OCEAN WATERS FROM LATE SATURDAY INTO SUNDAY NIGHT. ELSEWHERE THROUGH SUNDAY NIGHT...WINDS WILL BE MAINLY 10 KT OR LESS OVER THE REMAINDER OF THE WATERS AROUND LONG ISLAND. HIGH PRESSURE BUILDS OVER THE WATERS MONDAY AND TUESDAY RESULTING IN LIGHT WINDS AND RATHER TRANQUIL SEAS. && .HYDROLOGY... FORECASTING GENERALLY COUPLE TENTHS OF AN INCH OR LESS WITH ANY SHRA/TSTMS THROUGH THIS AFTN...THEN MAINLY DRY THROUGH SATURDAY. NO SIGNIFICANT HYDROLOGIC IMPACT IS EXPECTED FROM ANY PRECIPITATION THROUGH THE FIRST HALF OF NEXT WEEK. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...NONE. && $$ SYNOPSIS...MALOIT/PW NEAR TERM...SEARS SHORT TERM...MALOIT LONG TERM...PW AVIATION...JM MARINE...MALOIT/PW HYDROLOGY...MALOIT

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