Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 231730 AFDOKX Area Forecast Discussion National Weather Service New York NY 130 PM EDT TUE AUG 23 2016 .SYNOPSIS... High pressure over the region will slide offshore just to the south through Thursday. A cold front will slowly approach from late Thursday into Friday, and move across Friday evening. High pressure will follow for the weekend. Another frontal system will approach on Monday. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... Made minor changes to temperatures and dewpoints based observed trends this morning, otherwise forecast is on track. High pressure builds over the area today, resulting in another dry and pleasant day. Temperatures will reach the upper 70s and lower 80s, with dewpoints in the lower 50s. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/... High pressure dominates the area through the middle of the week. Winds begin to shift tonight to the southwest then eventually to the south by Wednesday, as high pressure begins to slide east of the area. This will allow dewpoints and temperatures to slowly creep upward on Wednesday. Low temperatures tonight will be in the mid and upper 50s inland, and lower to mid 60s along the coast, with max temperatures on Wednesday in the lower and mid 80s. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... An upper ridge over the Southern states will gradually build northeast through Friday, and become anchored along the southern Mid Atlantic coast through the weekend. With the area remaining near the southern fringe of the westerlies and with passing mid level shortwaves, we will have to contend with a cold frontal passage on Friday, followed by surface high pressure building eastward from the Great Lakes this weekend. We should experience one more comfortable night Wed night, with low humidity and lows near 70 in NYC and in the 60s most elsewhere. Dewpoints will then gradually rise Thu into Fri ahead of the cold front, but with a return southerly flow of maritime air becoming established, temps on Thu should be a little cooler than those of Wed, especially from from NYC east, with lower and mid 80s. This onshore flow and surface ridging near the coast should put a lid on most convection with a pre-frontal trough and approaching shortwave except well NW of NYC late day Thu, and then we should see only low chance PoP NW and slight chance elsewhere Thu night as heights fall aloft and the sfc ridge weakens. Instability is marginal so chances for thunder were capped at slight chance. The cold front itself will be relatively moisture starved compared to the pre-frontal trough Thu night, so have only mentioned slight chance for thunder Fri into Fri evening until the frontal passage. Temps should be very warm, reaching the lower 90s in NYC metro and the upper 80s most elsewhere, with heat index values reaching the mid 90s. Per higher end ensemble guidance cannot rule out high temps being a little warmer than that, with lower/mid 90s and the heat index possibly nearing 100 in NYC and urban NE NJ for one day. A somewhat cooler and less humid air mass will move in for the weekend as the surface high builds from the Great Lakes, with highs in the 80s and dewpoints in the 60s. There is still a hint of some isolated convection late day Sunday, but this looks to be upslope component terrain induced activity, favoring locations just out of the forecast area. Have removed from the forecast attm. A strong northern stream shortwave trough is also still progged to drop ESE along a warm front toward the Northeast on Monday. This is so far out in time that chances remain limited and mainly NW of NYC. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... High pressure over the region slides to the south tonight. VFR through the period. Sea breezes expected at coastal terminals today. KEWR/KTEB/KHPN likely shift to the west for a few hours this afternoon before sea breeze moves in. Sea breeze front may have trouble making it completely through KEWR, but instead battle a WSW flow and waver in the vicinity of the terminal. Winds become light and veer to SW tonight. Seabreezes are expected once again on Wednesday. NY Metro Enhanced Aviation Weather Support... Detailed information, including hourly TAF wind component forecasts, can be found at: http:/ KJFK TAF Comments: no unscheduled amendments expected. KLGA TAF Comments: Southerly sea breeze development expected between 18Z-20Z. KEWR TAF Comments: SE sea breeze development possible between 19Z-22Z. Wind direction could waver between WSW and SE during this time. KTEB TAF Comments: Sea breeze development likely between 20Z- 22Z. Wind direction could waver btwn WSW and S during this time. KHPN TAF Comments: Sea breeze development likely between 19Z- 22Z. KISP TAF Comments: SSW sea breeze development expected by 19Z. .Outlook for 18Z Wednesday through Sunday... .Wednesday...vfr. afternoon seabreezes expected. .Thursday...Slight chance of late day and nighttime showers/tstms, with brief MVFR conditions possible. Best chances North and West of NYC. .Friday...Slight chance of afternoon showers/tstms, with brief MVFR conditions possible. .Saturday and Sunday...VFR. && .MARINE... Winds and seas should remain below SCA criteria into early next week. There is still a small chance that ocean seas could reach SCA criteria some time Thu night into Fri ahead of a cold frontal passage. There is also a suggestion of tropical swell encroaching on the waters by Sunday. && .HYDROLOGY... Dry conditions expected across the area through the middle of the week. Winds and seas should remain below SCA criteria into early next week, though there is a small chance ocean seas could reach SCA criteria some time Thu night into Fri ahead of a cold frontal passage. There is also a suggestion of tropical swell encroaching on the waters by Sunday. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...FIG/Goodman NEAR TERM...FEB/MET SHORT TERM...FIG LONG TERM...Goodman AVIATION...BC MARINE...FEB/MET HYDROLOGY...FIG/Goodman is the U.S. government's official web portal to all federal, state and local government web resources and services.