Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 302031 AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 431 PM EDT WED JUL 30 2014 .SYNOPSIS... WEAK HIGH PRESSURE OVER THE MID-ATLANTIC REGION MOVES OFFSHORE TONIGHT. UPPER LEVEL DISTURBANCE PASSES NORTH AND WEST OF THE REGION ON FRIDAY. A FRONTAL BOUNDARY WILL DEVELOP ALONG THE COAST THROUGH THE WEEKEND. A COLD FRONTAL PASSAGE IS LIKELY FOR THE BEGINNING OF NEXT WEEK. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... WEAK SHORTWAVE PASSES THROUGH THE REGION THIS EVENING. ANY CLOUDS ASSOCIATED WITH IT WILL DISSIPATE THIS EVENING WITH THE LOSS OF DIURNAL HEATING. HIGH PRES OVER THE MID-ATLANTIC MOVES OFFSHORE AS WELL...AND RESULTING RETURN FLOW WILL ALLOW FOR AN INCREASE IN MOISTURE OVER THE REGION. MID-LEVEL CLOUDS WILL SPREAD INTO AREAS WEST OF THE HUDSON RIVER TOWARDS DAYBREAK THURSDAY. WITH THE INCREASE IN LOW-LEVEL MOISTURE...SOME PATCHY FOG IS POSSIBLE...MAINLY IN THE OUTLYING AREAS. LOWS TONIGHT WILL DROP INTO THE MID AND UPPER 60S IN/AROUND NYC...WHILE MOST OTHER AREAS WILL DROP INTO THE UPPER 50S TO LOW 60S. LOWS IN OUTLYING PORTIONS OF THE LOWER HUDSON VALLEY... INTERIOR PORTIONS OF SOUTHERN CT...AND THE PINE BARRENS OF LONG ISLAND WILL DROP INTO THE MID 50S. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/... FAIRLY STRONG H5 SHORTWAVE PIVOTS AROUND CLOSED LOW NEAR THE HUDSON BAY IN CANADA AND PASSES JUST NORTH AND WEST OF THE LOCAL CWA. CAPE VALUES WILL RISE CLOSE TO 1000 J/KG AND 0-6 KM BULK SHEAR WILL INCREASE TO 40-50 KT. THE LIFTED INDEX WILL BE FAIRLY WEAK... GENERALLY RANGING FROM -1 TO -2C. WITH THE BULK OF THE ENERGY STAYING NORTH OF THE REGION...WILL KEEP POPS CAPPED AT CHANCE...AND WILL EXPECT SCATTERED SHOWERS/TSTMS STARTING IN THE LATE MORNING...TAPERING OFF BY THURSDAY EVENING. DO THINK STORMS WILL BE HARD TO MAKE IT TO FAR SE CT AND EASTERN SUFFOLK COUNTY...AND WILL KEEP POPS CAPPED AT SLIGHT CHANCE FOR THOSE AREAS. MAX TEMPS GENERALLY RUNNING NEAR OR A COUPLE OF DEGREES BELOW NORMAL ON THURSDAY WITH HIGHS IN THE LOW 80S FOR NYC...LONG ISLAND...NE NJ...AND IN THE UPPER 70S TO AROUND 80 ELSEWHERE. ANY SHOWERS/TSTMS WILL TAPER OFF IN THE EVENING. LIGHT...ONSHORE FLOW REMAINS OVER THE REGION WITH SFC DEW POINTS RISING INTO THE LOW-MID 60S. PATCHY FOG POSSIBLE AFTER MIDNIGHT THURSDAY NIGHT AWAY FROM NYC. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... FRIDAY...INSTABILITY ACROSS MAINLY THE INTERIOR AREAS WILL SET THE STAGE FOR SCATTERED CONVECTION DURING THE AFTERNOON HOURS. SATURDAY AND SUNDAY...A SURFACE LOW PRESSURE ALONG THE ATLANTIC COAST...AND SUBTROPICAL MOISTURE ASSOCIATED WITH A BERMUDA RIDGE WILL AID IN THE DEVELOPMENT OF SHOWERS/THUNDERSTORMS SATURDAY AND SUNDAY. THE 12Z/GFS CONTINUES TO HAVE THE BEST FORCING FOR CHANCE OF SHOWERS TO BE ON SUNDAY...WHILE 12Z/ECMWF SHOWS THE BEST FORCING TO BE ON SATURDAY. WILL CONTINUE WITH PREVIOUS THINKING AND MAINTAIN 40/50 POP FOR THE WEEKEND. MONDAY AND TUESDAY...A LOW PRESSURE MOVING THROUGH THE GREAT LAKES REGION WILL BRING A COLD FRONT TOWARDS THE AREA. THIS WILL KEEP SCHC POPS ON MONDAY...WITH DRIER AIR MOVING IN ON TUESDAY. TEMPERATURES THROUGH THE EXTENDED PERIOD WILL BE CLOSE TO SEASONABLE LEVELS. && .AVIATION /21Z WEDNESDAY THROUGH MONDAY/...
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WEAK HIGH PRESSURE BUILDS OFFSHORE THROUGH TONIGHT. VFR THROUGH THE TAF PERIOD. COULD SEE CEILINGS AROUND 5000 FT DEVELOP BY MID-LATE THURSDAY MORNING. THERE IS A SLIGHT CHANCE AREAS N/W OF NYC COULD SEE AN ISOLD SHRA THURSDAY PRIOR TO 18Z...BUT PROBABILITY OF THIS IS TOO LOW TO REFLECT IN THE TAFS AT THIS TIME. SEABREEZE ALREADY THROUGH KJFK/KBDR/KGON/KISP. SHOULD PUSH THROUGH KLGA/KHPN LATER THIS AFTERNOON. FOR NOW EXPECT TO APPROACH BUT NOT MOVE THROUGH KTEB AND KEWR...SO ONLY BACK WINDS TO SW AT THOSE LOCATIONS. WINDS BECOME LIGHT AND VARIABLE/LIGHT SW AGAIN TONIGHT. SEABREEZE SHOULD DEVELOP A TAD EARLY THURSDAY THAN IT DID TODAY. ..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: CHANGES IN WIND DIRECTION/SPEED COULD BE OFF +/- 1-2 HOURS. KLGA FCSTER COMMENTS: SEABREEZE TIMING COULD BE OFF +/- 1-2 HOURS. KEWR FCSTER COMMENTS: NO SEABREEZE FORECAST...BUT CHANGES IN WIND DIRECTION/SPEED COULD BE OFF +/- 1-2 HOURS. KTEB FCSTER COMMENTS: NO SEABREEZE FORECAST...BUT CHANGES IN WIND DIRECTION/SPEED COULD BE OFF +/- 1-2 HOURS. KHPN FCSTER COMMENTS: SEABREEZE TIMING COULD BE OFF +/- 1-2 HOURS. KISP FCSTER COMMENTS: CHANGES IN WIND DIRECTION/SPEED COULD BE OFF +/- 1-2 HOURS. .OUTLOOK FOR 18Z THURSDAY THROUGH MONDAY... .THURSDAY AFTERNOON-MONDAY...VFR...EXCEPT MVFR OR LOWER POSSIBLE IN ANY ISOLD-SCT SHRA/TSTMS THAT ARE POSSIBLE MAINLY IN THE AFTERNOON/EVENING EACH DAY.
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&& .MARINE... WITH HIGH PRES OVER THE WATERS...CAN EXPECT SUB-SMALL CRAFT ADVISORY CONDS THROUGH FRIDAY. WINDS AND SEAS WILL REMAIN BELOW SMALL CRAFT ADVISORY LEVELS THRU THE EXTENDED PERIOD. && .HYDROLOGY... BRIEF...LOCALLY HEAVY DOWNPOURS POSSIBLE IN SCATTERED TSTMS ON THURSDAY...BUT NOT EXPECTING MORE THAN LOCALIZED NUISANCE FLOODING. A HUMID AIR MASS WILL BE CONDUCIVE TO THE DEVELOPMENT OF HEAVY SHOWERS THIS WEEKEND. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...NONE. && $$ SYNOPSIS...FIG/MPS NEAR TERM...MPS SHORT TERM...MPS LONG TERM...FIG AVIATION...MALOIT/MET MARINE...FIG/MPS HYDROLOGY...FIG/MPS

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