Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 251738 AFDOKX Area Forecast Discussion National Weather Service New York NY 138 PM EDT MON JUL 25 2016 .SYNOPSIS... A cold front approaches this afternoon and moves through the region tonight. High pressure builds to the west Tuesday and moves off the southeast coast Wednesday into Thursday. A weak cold front approaches the region Friday and may linger into the weekend. && .NEAR TERM /THROUGH TONIGHT/... Severe thunderstorm watch in effect for a good portion of the area through the remainder of the afternoon. Sunshine will give way to increasing clouds and thunderstorms approach and move through from nw to se. Shearing northern stream shortwave then approaches late today with pre-frontal trough approaching the region late this afternoon crossing the region this evening. Trailing cold front crosses tonight. Temps continue to heat up early this afternoon. Temperatures away from the south coasts should be able to climb into the lower to mid 90s...with dewpoints rising into the lower 70s. Heat indices of 100 to 104 expected across nyc/NJ metro...with potential for 105+ if dewpoints advecting NE from southern NJ/se PA don`t mix out. For most of the remainder of the region...heat indices peaking around 100 degrees. The exception will be southern and eastern coastal areas limited to the mid to upper 80s due to morning cloud cover and onshore flow. Despite this...heat indices could still peak in the mid to upper 90s as dewpoints should surge into the lower to mid 70s. In terms of convection...tracking convection heading toward nw zones. Higher resolution models track these two complexes through the area this afternoon. Strengthening uni-directional deep layer shear and tstm coverage should support storm organization into strong to severe storms line segments affecting NYC/NJ/LI metro and points N/NW/W. Damaging winds from wet micro/macro bursts looks like the main threat based on uni-directional wind fields...deep moisture...and inverted V soundings. Relatively quick storm motions should localize flash flood threat to areas with training tstms. Convection should become elevated and weaken this evening as it translates farther east across LI/Southern CT as it runs into a deeper marine stable layer. Convection should push offshore by around midnight as shortwave axis moves across. Drier air slowly advects in late tonight with weak cold frontal passage. Areas of fog possible across outlying areas in warm and muggy airmass. There is a moderate risk of rip current development this afternoon into evening as southerly wind waves increase to around 3 ft. && .SHORT TERM /TUESDAY/... Shortwave axis slides offshore Tuesday...with deep WNW flow on Tuesday. With 850 hpa temps still running in the high teens...deep mixing...downslope flow and full sunshine...expect temps to quickly rise into the mid 90s for much of the coastal plain. Lower 90s for nw hills...and potential for a few upper 90s for NYC/NJ metro. Noticeably lower dewpoints should keep heat indices close to air temps...but close to heat advisory criteria for NYC metro. Sea breezes should be limited to late day and immediate south coasts...if at all. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... High pressure builds across the area on Tuesday night then moves offshore on Thursday. A stalled frontal boundary south of the area will remain through the weekend. Showers and thunderstorms are possible during the afternoon and evenings Thursday and through the weekend, as waves of low pressure begin to ride along this frontal boundary. Temperatures on Wednesday and Thursday will be above normal with highs in the upper 80s to lower 90s and returning to normal levels on Friday and through the weekend with highs in the low to mid 80s. && .AVIATION /17Z MONDAY THROUGH FRIDAY/... Showers and thunderstorms are expected this afternoon and evening. First line of showers and thunderstorms should effect KSWF early afternoon and should stay north of other terminals. A second line is expected to move through all terminals late afternoon/early evening. VFR through this evening, except in thunderstorms where MVFR or lower visibilities briefly possible. S-SW flow 10-15 KT through this evening, with winds shifting to the west or west-northwest overnight after cold front passage. MVFR or lower visibility in fog possible for KHPN, KSWF, and KGON. ...NY Metro Enhanced Aviation Weather Support... KJFK TAF Comments: An occasional gusts to 20 kt possible through the afternoon. A shower or thunderstorm could develop a few hours earlier than indicated before the main line of storms late afternoon/early evening. KLGA TAF Comments: An occasional gusts to 20 kt possible through the afternoon. A shower or thunderstorm could develop a few hours earlier than indicated before the main line of storms late afternoon/early evening. KEWR TAF Comments: An occasional gusts to 20 kt possible through the afternoon. A shower or thunderstorm could develop a few hours earlier than indicated before the main line of storms late afternoon/early evening. KTEB TAF Comments: Winds should veer to the SW by 19Z. A shower or thunderstorm could develop a few hours earlier than indicated before the main line of storms late afternoon/early evening. KHPN TAF Comments: Winds should veer to the SW by 19Z. A shower or thunderstorm could develop a few hours earlier than indicated before the main line of storms late afternoon/early evening. KISP TAF Comments: Amendments for TSRA timing this afternoon/evening likely. .OUTLOOK FOR 18Z TUESDAY THROUGH SATURDAY... .Tuesday Afternoon-Thursday...VFR. .Thursday Night-Saturday...MVFR or lower possible in a chance of showers and thunderstorms. && .MARINE... Sub sca conditions expected through Tuesday. S/SW winds gusts to 20 kt possible for most waters this afternoon...with nearshore NW winds gusts to 20 kt possible Tuesday afternoon. Occasional nearshore gusts to 25 kt possible. Ocean seas should remain in the 2 to 4 ft range. Greater chance for thunderstorms late this afternoon through this evening. Below small advisory conditions expected across the area waters from Tuesday through Friday. && .HYDROLOGY... There is the potential for 1/4 to 1/2 inch of rainfall, with locally higher amounts, possibly 2+ inches, as numerous showers and thunderstorms track across the region late this afternoon into this evening. This presents a localized flash flood threat...mainly across NYC/NJ metro and interior with any training cells. There is the potential for scattered showers and thunderstorms, across the area during the afternoons and evenings Thursday through next weekend. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...Heat Advisory until 8 PM EDT this evening for CTZ005>007-009- 010. NY...Heat Advisory until 8 PM EDT this evening for NYZ067>075-078- 080-176>179. NJ...Heat Advisory until 8 PM EDT this evening for NJZ002-004-006- 103>108. MARINE...None. && $$ SYNOPSIS...FIG/NV NEAR TERM...NV/PW SHORT TERM...NV LONG TERM...FIG AVIATION...DS MARINE...FIG/NV/PW HYDROLOGY...FIG/NV

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