Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 261847 AFDOKX Area Forecast Discussion National Weather Service New York NY 247 PM EDT TUE JUL 26 2016 .SYNOPSIS...
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A weak front will move across this evening. 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.
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&& .NEAR TERM /THROUGH TONIGHT/...
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Weak sfc trough will remain in place late this afternoon, while mainly NW flow will continue to gust to 15-20 kt. Expect sct Cu mainly over NYC metro and the interior to dissipate this evening, then weak front to the NW should pass through this evening after loss of daytime heating, with winds becoming light northerly. Sided with the cool end of guidance for lows tonight, with a wide range of temps, from the 70s invof NYC, to the 60s most elsewhere, to some upper 50s in some interior valleys. Rip current risk remains moderate as primary southerly swells increase to 3 ft with a 6-7" period, along with a secondary residual long period 1-ft SE swell.
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&& .SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...
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Models continue to agree on the region lying between a closed low over Quebec and flat SE US ridging, with zonal flow aloft. At the surface, high pressure will give way to weak thermal troughing developing in the afternoon. Hot conditions will continue, with highs 90-95, near or slightly above the warmest MOS guidance. Dewpoints in the upper 50s and lower 60s will keep heat index values at or just below ambient temperatures, so do not plan to extend the heat advisory for NYC. Temps Wed night will be similar to those forecast for tonight, will perhaps a little more widespread upper 50s across the interior.
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&& .LONG TERM /THURSDAY THROUGH MONDAY/...
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Zonal upper flow to start will back to the SW ahead of developing Great Lakes troughing. At the surface, weak high pressure should move east on 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. Some increase in dewpoints is likely Thu with return flow, which should have heat index values returning to the mid to upper 90s for NYC/NJ metro and the Lower Hudson Valley. 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.
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&& .AVIATION /19Z TUESDAY THROUGH SUNDAY/... 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. && .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...
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Hot and dry late this afternoon, with wind gusts up to 20 mph and min RH values in the 30s ad 40s. A locally elevated threat for brush fire spread exists for areas that received little rainfall. SPS was issued earlier for SE CT to address this per request of CT officials. Hot and dry conditions continue on Wednesday with min RH values in the 20s and 30s. Winds should be lighter than those of today.
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&& .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...Goodman NEAR TERM...Goodman SHORT TERM...Goodman LONG TERM...FIG AVIATION...DW MARINE...Goodman FIRE WEATHER... HYDROLOGY...FIG/NV

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