Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 192339 AFDOKX Area Forecast Discussion National Weather Service New York NY 739 PM EDT Thu Apr 19 2018 .SYNOPSIS... Deepening low pressure lifts up into the Canadian Maritimes tonight into Friday, while high pressure builds in slowly from the Midwest into Monday, then moves offshore late Monday. A coastal low approaches from the southeastern seaboard Tuesday, and moves through Wednesday, and to the northeast of the area Thursday. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
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An upper trough and offshore surface low lift northeast tonight. A few residual rain and snow shwrs possible this eve...otherwise dry. Cold advection and a strong pressure gradient behind the low will result in NW winds gusting up to 30 mph for much of the night. There could be some lulls with the more frequent gusts near the coast. Temperatures will drop into the 30s which is close to 10 degrees below normal. This coupled with the gusty winds will make it feel more like the 20s.
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&& .SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/... Deepening low pressure continues to track across the Canadian Maritimes on Friday, while high pressure builds east from the Midwest. This will maintain a gusty NW flow into early Friday evening. Outside of some instability clouds on Friday, expect mostly clear skies with temperatures remaining below normal. While warmer than Thursday, highs will only top out in the lower 50s, with lows Friday night in the lower to mid 30s. There could be some patchy frost as well across the interior as winds diminish overnight. && .LONG TERM /SATURDAY THROUGH THURSDAY/... Surface high pressure will be over the region Saturday into Monday. Meanwhile, cyclonic upper flow will remain into Sunday as a longwave trough and closed low remains across eastern Canada and into the northeast. A southern stream shortwave moves slowly out of the plains and into the southeastern states Sunday night into Monday. Some weak energy does rotate through the upper trough into Sunday, however, with low level subsidence and little moisture the area remains dry with little cloudiness. Guidance similar through Monday. Thereafter the handling of the southern stream wave diverges. , And latest guidance now handling wave differently from previous runs. The GFS keeps a more cutoff and closed system for a time over the southern states and then the shortwave trends to becoming negative. This has resulted in the surface low now being a little slower moving north along the coast. Meanwhile the ECMWF keeps an open wave and is more progressive and farther east from the track of the GFS for the surface low. Aimed for a compromise and a slower solution, thus having chance to likely probabilities late Tuesday night into Thursday. No p-type issues, all light rain Tuesday night into Thursday. && .AVIATION /00Z FRIDAY THROUGH TUESDAY/...
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Deepening low pressure lifts up into the Canadian Maritimes tonight into Friday, while high pressure builds in slowly from the Midwest. VFR conditions expected as broken clouds scour out overnight. Northwest winds 10-20 kt with gusts 20-30kt are expected tonight. As the night progresses, gusts may become less frequent, especially outside NYC metro terminals. NW winds continue Friday, and gusts will be frequent, gusting 20 to 30 kt. 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 should fluctuate on either side of 300 true. Gusts will continue tonight. KLGA TAF Comments: Winds should fluctuate on either side of 300 true. Gusts will continue tonight. KEWR TAF Comments: Winds should fluctuate on either side of 300 true. Gusts will continue tonight. KTEB TAF Comments: Gusts may become less frequent after midnight. KHPN TAF Comments: Gusts may become less frequent after midnight. KISP TAF Comments: Gusts may become less frequent after midnight. .OUTLOOK FOR 00Z SATURDAY THROUGH TUESDAY... .Friday night...VFR with diminishing NW winds. .Saturday-Monday...VFR. .Tuesday...VFR, with a chance of sub-VFR conditions in rain late or at night.
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&& .MARINE... Behind a departing low lifting up into the Canadian maritimes through Friday, gusty NW winds develop across the waters this evening and continue into Friday with sub-SCA conditions developing from west to east during the afternoon hours. High pressure will be over the forecast waters Saturday into Monday, then slide off the northeast coast Monday night into Tuesday. Winds and seas will be below SCA levels through Tuesday. Low pressure moves north along the coast Tuesday into Thursday. A developing southerly flow late Monday will persist and increase into Wednesday. By Tuesday night ocean seas are expected to build to SCA levels. At this time ocean seas may not build as high as forecast and will depend on the strength of the southerly flow and track of the low midweek. && .HYDROLOGY... The next chance of rain is expected Tuesday night into Thursday. No significant hydrologic impacts are expected at this time. && .EQUIPMENT... NYC NOAA Weather Radio Station KWO-35 (162.55 MHz) remains off the air. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...Small Craft Advisory until 2 PM EDT Friday for ANZ330-335-338- 340-345-353-355. Small Craft Advisory until 6 PM EDT Friday for ANZ350. && $$ SYNOPSIS...MET/DW NEAR TERM...JMC/DW SHORT TERM...DW LONG TERM...MET AVIATION...BC/PW MARINE...MET/DW HYDROLOGY...MET/DW EQUIPMENT...

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