Area Forecast Discussion
Issued by NWS Upton, NY

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109 FXUS61 KOKX 270527 AFDOKX Area Forecast Discussion National Weather Service New York NY 127 AM EDT Tue Jun 27 2017 .SYNOPSIS... Weak high pressure builds farther offshore tonight as a cold front approaches from the Great Lakes. The front moves through the area Tuesday evening. High pressure will then briefly follow for the middle of the week. Another frontal system approaches for the end of the week. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... A weak surface trough was across the region from the Hudson Valley into eastern Pennsylvania and into north central Maryland. This was the focus of a few light showers, along with a shortwave rotating through an upper trough. Put probabilities, slight chance, into the forecast for areas across the far western zones initially and then slowly east through the overnight. The HRRR was also supporting the chance of showers overnight, just a couple of hours too quick. Lower levels are dry and any precipitation reaching the ground is expected to be light. Anomalously strong upper trough across the Great Lakes and Ohio Valley states pivots eastward the next couple of days with gradual height falls and increasing daytime instability. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM WEDNESDAY/... Airmass gradually destabilizes on Tuesday with height falls and approaching cold front over the Great Lakes. However, dry low- levels and lack of strong surface trigger will be limiting factors for the development of showers/thunderstorms. The best chance will be across the interior during the afternoon hours. Wind shear is also weak, limiting any organization. Cold front works across the area in Tuesday evening with high pressure to follow. Daytime highs will once again be near or just below seasonable levels. There is a moderate risk for the development of rip currents Tuesday. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... High pressure will be in control Wednesday through Thursday night, bringing dry conditions and near normal temperatures across the area. As high pressure moves offshore, warmer temperatures and increasing chances of showers and thunderstorms will develop Friday through Sunday. High pressure builds back on Monday, bringing more seasonable temperatures and dry conditions across the area. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/...
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VFR through the TAF period. A trough of low pressure passes across the terminals early this morning, followed by another one on Tuesday. Winds are a bit uncertain through the middle morning hours. However, speeds are expected to be less than 10 kt. Winds should veer to the W or NW in the next few hours over the city terminals with light and variable elsewhere. Winds will then gradually become southerly into the morning 10 kt or less. Winds veer to the SW into the afternoon and evening 10-15 kt, then to the W-WNW overnight around 10 kt. A few showers are possible early this morning, 08-11z over NYC terminals, and 10-13z Long Island and southern Connecticut terminals. An isolated shower/thunderstorm is also possible this afternoon. .OUTLOOK FOR 06Z WEDNESDAY THROUGH SATURDAY... .Tuesday Night-Wednesday...VFR. .Thursday...VFR. Chance of a late day shower/thunderstorm. .Friday and Saturday...MVFR or lower possible in showers and thunderstorms.
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&& .MARINE... Winds and seas forecast on track. With an overall weak pressure gradient remaining across the region, winds and seas are expected to remain below small craft advisory criteria (25kt winds, 5 ft seas) through Tuesday. Below small craft advisory conditions expected Wednesday as High pressure moves south across the area waters. Winds and seas increase, and small craft advisory conditions are possible later Thursday and into Saturday. && .HYDROLOGY... No hydrologic impacts expected through the beginning of next week. && .TIDES/COASTAL FLOODING... Astronomical tides are still running high with a low chance of any minor coastal flooding across the south shore back bays of Nassau county with this evening high tide cycle, approximately between 10pm and 12am. The water levels would only be expected to touch the minor benchmarks few just a couple of gages so no statement has been issued. && .EQUIPMENT... Observations from KFRG (Farmingdale, NY) are not available. Observations from KHPN (White Plains NY) and KHVN (New Haven CT) are being disseminated through backup methods. All is due to an FAA communication line outage. Return to service time is unknown. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...Fig/DW NEAR TERM...MET/DW SHORT TERM...DW LONG TERM...Fig AVIATION...DS MARINE...Fig/MET/DW HYDROLOGY...Fig/DW TIDES/COASTAL FLOODING... EQUIPMENT...

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