Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 290548 AFDOKX Area Forecast Discussion National Weather Service New York NY 148 AM EDT WED JUN 29 2016 .SYNOPSIS...
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A cold front will move slowly east across the Tri-State region today. Weak high pressure builds in tonight through Friday. A cold front then approaches and moves across the area late Friday night and Saturday. High pressure builds in behind the front from Saturday night through Tuesday.
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&& .NEAR TERM /UNTIL 6 AM THIS MORNING/...
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Showers have decreased across the area since last update. They should continue to do so with the loss of instability. However, with the cold front in the vicinity, and a humid airmass, there remains at least a chance for showers through much of the rest of tonight. Also, added patchy fog to the entire area as light winds prevents any mixing. Western areas may see conditions improve before daybreak as the cold front moves through. Winds may increase just enough behind the front to allow the fog to mix out. Otherwise, forecast is on track. For lows tonight, a blend of MAV/MET/ECS guidance and NAM 2-meter temperatures were used, with values forecast to be a few degrees above normal.
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&& .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM THURSDAY/... Core of 700-500 hPa trough lifts NE into eastern Quebec Wednesday, taking the best dynamics with it. Best jet forcing will be in the morning with the region in the right rear quadrant of a 75-80 KT 300 hPa jet and having a 50 KT 500 hPa jet pass over western portions. However, the mid levels are forecast to be rather dry, along with a cap centered around 650 hPa, with these likely being the limiting factors in any convective development. For now have slight chance pops across the N tier of the CWA Wednesday (area closest to the best dynamic forcing), mainly E of the Hudson River, with a dry forecast elsewhere. Highs Wednesday were based on a blend of MAV/MET/ECS guidance, NAM 2-meter, and a mix down from 950-800 hPa per BUFKIT soundings. Highs should be around 5 degrees above normal, except near normal in the immediate NYC Metro area. The main 700-500 hPa trough axis exits to the east Wednesday evening, with drier air working in behind it in the low levels, to go with the already dry air aloft. As a result, expect any cloud cover to clear out overnight, with decent radiational cooling setting up. Based on this, lows were weighed towards coolest of MAV/MET/ECS guidance and NAM 2-meter temperatures at any given point outside of urban areas. Lows should be near normal. && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... Weak high pressure builds across the area on Thursday and Friday. A cold front will move through the area late on Friday night and into early Saturday, brining showers and the potential for some thunderstorms. High pressure builds behind the front Sunday and remains through the holiday weekend. Temperatures during the extended period will be near normal for this time of year, with temperatures during the day in the low to mid 80s and low temperatures in the upper 50s to lower 60s. && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
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A cold front will move slowly east across the local area today followed by high pressure tonight. SCT SHWRS will end from W to E by 12z. Because winds will remain light overnight, areas of IFR/LIFR fog, locally dense will form in a humid air mass. CIGS from the NYC Metro area East will range from LIFR to MVFR until 12z, with gradual improvement N and W of NYC. For tonight...forecast uncertainties remain with the locations and timing for fog development. For Wednesday...forecast uncertainties remain with timing the development of sea breezes around 10 kt following NW winds of 10-15 kt between 12z and 17z. Can not rule out an isolated or even widely SCT TSTMs aft 18z area wide. .OUTLOOK FOR 06Z THURSDAY THROUGH SUNDAY... .Wednesday night through Friday morning...VFR. .Friday afternoon and night...MVFR or IFR conditions possible in showers/tstms. .Saturday and Sunday...VFR.
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&& .MARINE... Added patchy fog to the ocean and South Shore Bays tonight. Otherwise, a relaxed pressure gradient over the waters around Long Island will keep winds at 10 kt or less through Wednesday night. With no significant swells forecast, seas/waves should be 3 ft or less as well during this time frame. Winds and seas are forecast to remain below small craft advisory levels Thursday through the holiday weekend. && .HYDROLOGY...
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Up to 1/2 inch of rain is forecast through tonight, with locally higher amounts possible mainly west of the Hudson River. Areas that do experience locally heavy rainfall could experience minor flooding of urban/poor drainage areas with a very small chance of localized flash flooding. However, most areas will receive no hydrologic impact from this rainfall. No significant rainfall is expected from Wednesday through Friday. Scattered showers and thunderstorms are possible late Friday night and into early Saturday. Antecedent conditions are very dry, so widespread hydrology issues are not expected.
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&& .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...FIG/Maloit NEAR TERM...JP SHORT TERM...Maloit LONG TERM...FIG AVIATION...GC MARINE...JMC/FIG/Maloit HYDROLOGY...FIG/Maloit

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