Area Forecast Discussion
Issued by NWS Upton, NY

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537 FXUS61 KOKX 182351 AFDOKX Area Forecast Discussion National Weather Service New York NY 751 PM EDT Thu Oct 18 2018 .SYNOPSIS... High pressure will remain in control through Friday, drifting south and east of the area Friday afternoon. A cold front approaches Friday night. The cold front will sweep across the area Saturday evening with brisk conditions into Sunday as high pressure builds from the west. The high will shift off the Mid Atlantic coast on Monday followed by a weak clipper like system tracking through New England on Tuesday. High pressure then returns for mid week. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... The fcst is on track this eve. Surface high pressure builds toward the mid Atlantic coast tonight. With the high in the vicinity, winds will continue to diminish, and skies will be nearly clear. There will be some weak warm advection tonight at 900 to 850 MB. If winds decouple, and become light, especially across the interior, temperatures will likely fall to below freezing. So have kept the freeze warnings and frost advisories in effect. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY/... High pressure will move off the mid Atlantic coast Friday and a longwave trough with a shortwave rotating into the western portion moves into the Great Lakes by the end of the day. One shortwave moves across the area Friday night ahead of a more potent wave and associated cold front approaching Saturday. Have brought chance and slight chance probabilities into the region with the shortwaves and cold front Friday night into Saturday. Temperatures will be warm enough for the precipitation to be all liquid. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... Global models are in good agreement with the upper pattern through early next week with fall like weather continuing in the northeast. Long wave trough axis over the eastern Great Lakes/Ohio Valley Sat night will shift east of the New England coast on Sun with zonal flow briefly developing Mon ahead of the next shortwave Tue. This is where solutions diverge in the global models. The GFS is more amplified and more progressive with building heights for the middle of next week while the ECMWF is broader at H5 with another shortwave diving down from central Canada for Thu. At the sfc, a cold front will sweep across the area Sat eve with low chances for rain continuing until the upper trough axis swings through Sat night. Dry and unseasonably cool weather is then forecast for the remainder of the period, although PoPs on Tue may increase in subsequent forecast packages if there is a bit more moisture for a clipper like system to work with in southern New England. Otherwise, brisk Sat night and Sun due to the combination of CAA behind the front and a tightening pressure gradient between strengthening low pres to the north and a building high to the west. && .AVIATION /00Z FRIDAY THROUGH TUESDAY/... VFR as high pressure builds to the south of the region into Friday evening. VFR through the TAF period. WNW winds withs speeds falling below 10 kt throughout by mid- late evening. Winds become light and variable tonight except at KJFK and KLGA. Winds become WSW- SW at around 10-15KT by mid Friday morning. Gusts to around 15-20KT are probable at all terminals by around midday Friday. Gusts could abate outside of NYC terminals by early Friday evening. 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: Timing of changes in wind speed and direction could be off +/- 1-2 hours. KLGA TAF Comments: Timing of changes in wind speed and direction could be off +/- 1-2 hours. KEWR TAF Comments: Timing of changes in wind speed and direction could be off +/- 1-2 hours. KTEB TAF Comments: Timing of changes in wind speed and direction could be off +/- 1-2 hours. KHPN TAF Comments: Timing of changes in wind speed and direction could be off +/- 1-2 hours. KISP TAF Comments: Timing of changes in wind speed and direction could be off +/- 1-2 hours. .OUTLOOK FOR 00Z SATURDAY THROUGH MONDAY... .Friday night-Saturday...MVFR possible, there is also a chance of showers. SW winds G15-25KT possible Saturday. .Saturday night-Sunday...VFR. W-NW winds G15-25KT possible. .Sunday night-Tuesday...VFR. W-SW winds G15-20KT possible Tuesday. && .MARINE... High pressure was building slowly in from the west and the pressure gradient forces was weakening as heights were rising. Also, cold advection and low level winds were diminishing. As a result, the winds and gusts across the waters were below SCA, and the advisory that was in effect into this evening was cancelled. The may still be occasional gusts to around 25 KT across the ocean waters east of Moriches Inlet early this evening. Winds and seas will remain below SCA levels into Friday morning. As high pressure drifts to the south and east Friday and a longwave trough digs into the Great Lakes and northeast Friday, the pressure gradient will increase, along with low level winds. So, expect wind gusts to increase to SCA levels by late Friday morning across all the waters, and a SCA has been posted beginning at 15Z, continuing into Saturday. Winds continue to increase especially on the ocean waters, as low level winds increase too, and gusts will likely be near gale force Friday night into Saturday. A gale watch has been issued on the ocean waters Friday night into Saturday morning. The combination of CAA behind a cold front and a tightening pressure gradient between strengthening low pressure to the north and a building high to the west will result in SCA to possibly gale force conditions Sat night through Sun, before gradually diminishing Sun night. Sub-advsy conds return on all waters by Mon morning, although marginal winds and seas are possible late Mon night and Tue. && .HYDROLOGY... No hydrologic issues are expected through the middle of next week. && .EQUIPMENT... NYC NOAA Weather Radio Station KWO35 (162.55 MHz) remains off the air for an extended period of time. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...Frost Advisory from 3 AM to 9 AM EDT Friday for CTZ010>012. Freeze Warning from 3 AM to 9 AM EDT Friday for CTZ005>008. NY...Frost Advisory from 3 AM to 9 AM EDT Friday for NYZ069-070- 078>081. Freeze Warning from 3 AM to 9 AM EDT Friday for NYZ067-068. NJ...Frost Advisory from 3 AM to 9 AM EDT Friday for NJZ004-103-105- 107. Freeze Warning from 3 AM to 9 AM EDT Friday for NJZ002. MARINE...Small Craft Advisory from 11 AM Friday to 6 PM EDT Saturday for ANZ330-335-338-340-345. Gale Watch from Friday evening through Saturday afternoon for ANZ350-353-355. Small Craft Advisory from 11 AM to 6 PM EDT Friday for ANZ350- 353-355. && $$ SYNOPSIS...24/19 NEAR TERM...12/19 SHORT TERM...19 LONG TERM...24 AVIATION...Maloit MARINE...24/19 HYDROLOGY...24/19 EQUIPMENT...

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