Area Forecast Discussion
Issued by NWS Upton, NY

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756 FXUS61 KOKX 231722 AFDOKX Area Forecast Discussion National Weather Service New York NY 122 PM EDT Sun Oct 23 2016 .SYNOPSIS... Low pressure over southeastern Canada will gradually weaken over the next couple of days, while a clipper low and its associated cold front move through the area early Monday morning. High pressure builds across the area Tuesday and Wednesday, followed by a Pacific frontal system at the end of the week. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... Mixing well and higher winds have been making it down to the surface with peak wind gusts around 32 KTS. With the mixing dew points across the interior have lowered into the lower and mid 20s. Updated for temperatures, dew points, and winds across the area. Surface low pressure centered near the St Lawrence river will meander across southeastern Canada through today and into tonight as the upper closed low and negative trough remain across eastern Canada. With a well mixed boundary layer across the region temperatures will be fairly uniform...upper 50s to lower 60s. Drier air and weak subsidence will keep area cloud free until later this afternoon as clouds approach ahead of a shortwave moving through the northern stream. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/... Northern stream shortwave moves quickly east tonight and passes through the area after midnight. Decent lift along and ahead of the associated mid level short wave will result in a brief period of rain with up to a quarter inch possible. Most locations will dry out by daybreak Monday with the possible exception of far eastern LI and SE CT. Cold advection will follow through the day Monday with another shot of cold air following a short wave trough Monday evening. Amplifying upper ridge over the western U.S. ahead of the next Pacific storm system will help to amplify the downstream trough across eastern Canada and the northeast. In addition, an upstream block resides across the central Atlantic. This will result in a deep-layered NW flow across the area with a shot of unseasonably cold air to arrive Monday night and persist into mid week. Gusty northwest winds will continue during this time with weakening low pressure over eastern Canada and polar high pressure building southeast from central Canada. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... Upper trough remains across the northeastern portion of the country early to mid week, as ridge to the west eventually flattens per global models. Differences arrive with handling of shortwave that develops across the upper mid west as it traverses east late in the week. At the surface, low pressure associated with lingering upper trough moves slowly across eastern Canada, as high pressure builds out of central Canada and into the Great Lakes Region through mid week. The high briefly slides across the area Thursday before giving way to low pressure Thursday and Friday. Frontal boundaries, first warm front followed by the cold front, impact the area from late Thursday, into Friday. For Saturday, forecast becomes less clear. A possible weak frontal boundary may move through Saturday, but confidence in this remains low at this time. Generally dry conditions are anticipated through Wednesday night as high pressure slowly builds. Cyclonic flow could result in more cloud cover each day, especially into New England Tuesday and possibly Wednesday. The best chance for rain looks to be late Thursday, Thursday night into Friday. ECMWF slower with upstream system compared to usually quicker GFS. Temperatures will be below normal Tuesday and Wednesday, then slowly moderate closer to normal Thursday through Saturday. && .AVIATION /18Z SUNDAY THROUGH THURSDAY/...
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High pressure builds to the south today with strong low pressure over eastern Canada. A cold front moves through late tonight into early Monday. WNW winds gusting 25 to 30 kt, expected through around 21z. An isolated peak gust up to 35 kt cannot be ruled out. Gusts will end this evening. Winds decrease and gusts end this evening. Winds will back to the SW overnight, generally around 7-10 kt. After the cold front passage early Monday, winds will shift to the NW and increase with gusts 20-25 kt by late morning. VFR through the TAF period. There is a low chance for MVFR in light rain late tonight into early monday morning. .Outlook for 18Z Monday through Friday... .Monday Afternoon-Monday Evening...VFR. NW winds G20-25 kt. .Tuesday...VFR. NW winds G25-30 kt, diminishing Tuesday night. .Wednesday...VFR. NW-NNW G20 kt possible near the coast. .Thursday-Friday...MVFR or lower possible late Thursday into Friday in showers.
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&& .MARINE... Winds and gusts have diminished to below gale except across the eastern ocean waters east of Moriches Inlet...ANZ350. Wind gusts at small craft levels through this afternoon on the remainder of the waters, and on the ocean waters into Monday night with the passage of another cold front late tonight into early Monday as northwesterly winds will gust to small craft levels. There will be a lull in the winds late tonight and the surface low and front move through as the surface pressure gradient weakens. However seas on the ocean waters remain at small craft levels. Kept the gale warning for east of Moriches inlet through today. This may be changed to a small craft with the afternoon package if wind gusts continue downward trend. The gale warning was downgraded to a small craft through today on the Long Island sound, the Long Island bays, and New York Harbor. Finally, the gale warning was downgraded to a small craft advisory on the ocean waters west of Moriches Inlet through Monday night. Small craft conditions on the ocean waters are possible through Tuesday. Winds diminish again with a more substantial decrease of the pressure gradient Tuesday night with a Canadian high approaching. High pressure remains across the waters through early Thursday. && .HYDROLOGY... Up to a quarter inch of rain is possible tonight with a fast moving area of low pressure. Rainfall of 1/2 inch or more is possible Thursday into Friday. No hydrologic impacts are anticipated. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...Small Craft Advisory until 6 PM EDT this evening for ANZ330- 335-338-340-345. Small Craft Advisory until 6 AM EDT Tuesday for ANZ353-355. Gale Warning until 6 PM EDT this evening for ANZ350. && $$ SYNOPSIS...MET/DW NEAR TERM...MET SHORT TERM...MET/DW LONG TERM...DW/PW AVIATION...DS MARINE...MET HYDROLOGY...MET is the U.S. government's official web portal to all federal, state and local government web resources and services.