Area Forecast Discussion
Issued by NWS Upton, NY

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697 FXUS61 KOKX 261826 AFDOKX Area Forecast Discussion National Weather Service New York NY 226 PM EDT TUE JUL 26 2016 .SYNOPSIS... A weak front will move across today. High pressure will build from the west on Wednesday, and move east by Thursday. A weak cold front will approach the region Thursday night into Friday, and linger into the weekend. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... Shortwave axis slides offshore this morning, with deep WNW flow today. At the surface a weak trough will develop and push east today. With 850 hpa temps still running in the high teens, deep mixing, downslope flow, and just some thin cirrus, expect temps to rise into the lower to mid 90s for much of the coastal plain, and the upper 80s/Lower 90s for the NW hills. Sea breezes should be limited to late day and immediate south coasts, if at all. Noticeably lower dewpoints should keep heat indices close to air temps, mid/upper 90s for NJ metro and mid 90s for the rest of NYC metro. Heat advisory continues. The risk for rip current development will be moderate for SE Suffolk county beaches, and will become moderate this afternoon as primary southerly swells increase to 3 ft with a 6-7" period, along with a secondary residual long period 1 ft SE swell. && .SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/... Models in good agreement with the region lying between a closed low over northern Quebec and southeastern US ridging. Zonal upper flow to start will back to the SW ahead of developing Great Lakes troughing. At the surface, weak high pressure builds into the region Wed and moves offshore Thu. Hot conditions will continue for mid week with highs generally in the lower/mid 90s away from the south coasts. Based on warming aloft and deep mixing, could see a few upper 90s across NE NJ metro on Thu. Afternoon sea breeze development should keep south coastal areas in the upper 80s to lower 90s both days. Dewpoints should remain in the lower 60s, perhaps upper 50s during peak heating Wed, keeping heat indices at air temps. At this point it is likely heat indices stay below 95 degrees on Wed. A gradual moderation in dewpoints is likely Thu with return flow, which should have heat indices returning to the mid to upper 90s for NYC/NJ metro and Lower Hud. Otherwise, relatively comfortable temps tonight and Wed night, particularly outside the urban centers. Radiational cooling should allow for temps to drop into the lower to mid 60s across far outlying areas, to mid 70s for NYC/Nj metro. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... A weak cold front should move across from the northwest Thursday night into Friday. There is a chance of showers and thunderstorms late Thursday into Friday as the system crosses the area, with the possibility of some heavy rain depending on the track. The front may settle nearby through the weekend, setting the stage for unsettled weather with chances for showers and thunderstorms through Sunday. High pressure builds into the area Monday. Temperatures will be near normal Thursday night through Monday. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/...
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High pressure builds east from the Ohio Valley through tonight. Forecast challenge this afternoon is whether or not a seabreeze impacts the coastal terminals. May see brief winds shifts where the seabreeze moves in and then out. Preference at this time is to only mention seabreeze at KGON where the flow is weaker. The W/NW flow looks to be strong enough to prevail most of the time elsewhere. Winds generally 280-300 through this afternoon at 10 to 15 KT G20 KT. Winds become N early this evening and lower to less than 10 KT. LGT/VRB winds likely after midnight tonight. Winds veer around to the W/SW Wed afternoon with seabreezes at the coastal terminals as early as 14Z. ...NY Metro Enhanced Aviation Weather Support... Detailed information, including hourly TAF wind component forecasts, can be found at: http:/www.weather.gov/zny/n90 KJFK TAF Comments: Winds may vary by 20 degrees with the close proximity of a trough. Low chance of an afternoon seabreeze, KLGA TAF Comments: Winds may vary by 20 degrees with the close proximity of a trough. Gusts may be a few KT higher than forecast this afternoon. KEWR TAF Comments: Winds may vary by 20 degrees with the close proximity of a trough. Gusts may be a few KT higher than forecast this afternoon. KTEB TAF Comments: Winds may vary by 20 degrees with the close proximity of trough. KHPN TAF Comments: No unscheduled AMDs expected. KISP TAF Comments: Low chance of a late day seabreeze. .OUTLOOK FOR 18Z WEDNESDAY THROUGH SUNDAY... .Wednesday Afternoon-Thursday...VFR. Isolated showers and thunderstorms possible Thursday afternoon, mainly NW of the NYC terminals. .Thursday Night-Sunday...MVFR or lower possible with a chance of showers and thunderstorms. The best chance looks to be on Friday.
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&& .MARINE... Sub-SCA conditions will prevail through Thursday with a weak pressure gradient in place via building high pressure. Near shore gusts up to 20 kt possible off land areas this afternoon where sea breezes fail to develop. Below small craft advisory conditions expected across the area waters Friday through the weekend with a weak pressure gradient. && .FIRE WEATHER... Hot and dry today, with wind gusts 20-25 mph and min RH values in the 30s in the afternoon. A locally elevated threat for brush fire spread exists for areas that received little rainfall. SPS was issued earlier to address this per request of CT officials. Hot and dry conditions continue on Wednesday with min RH values in the 30s. Winds should be lighter than those of today. && .HYDROLOGY... There is potential for scattered showers and thunderstorms from late Thursday into the weekend. While locally heavy rainfall is possible, it is much to early to pin down details. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...Heat Advisory until 6 PM EDT this evening for NYZ072>075-176- 178. NJ...None. MARINE...None. && $$ SYNOPSIS...NV NEAR TERM...Goodman/NV SHORT TERM...NV LONG TERM...FIG AVIATION...DW MARINE...FIG/NV FIRE WEATHER...// HYDROLOGY...FIG/NV

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