Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 220525 AFDOKX Area Forecast Discussion National Weather Service New York NY 125 AM EDT Mon Oct 22 2018 .SYNOPSIS... High pressure will build to the south through Monday. As low pressure passes to the north late Monday night into Tuesday, a warm front will approach and pass through. A cold front will follow Tuesday night. High pressure will then build across from Wednesday into Thursday, and settle over the region on Friday. The high will retreat on Saturday, followed by low pressure lifting north along the Eastern seaboard Saturday night into Sunday. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... Expect a mostly clear night tonight, except perhaps in interior portions of the Lower Hud Valley and NE NJ where lake effect clouds have been advancing SE the past few hours. Winds continue to diminish and will remain light overnight as high pressure builds to the SW. The light winds and mostly clear skies will allow for ideal radiational cooling conds. Although weak WAA will commence tonight, H85 temps between -3C and -5C will yield lows in the upper 20s to mid 30s across most of the Tri State Area. The NY/NJ metro area will be slightly warmer, but still chilly with lows in the upper 30s to lower 40s. No changes to frost/freeze headlines. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM TUESDAY/... Expect dry conditions Mon into Mon evening as sfc high pressure slides to the south and heights rise aloft. There could be a period of mostly cloudy skies well inland Mon afternoon as an H8 warm front passes across upstate NY into New England. High temps will be not too far off those of today, mainly upper 40s/lower 50s. As the core of the sfc high moves offshore Mon night and low pressure crosses the upper Great Lakes into Ontario, a warm front approaching from the south should bring mostly cloudy skies Mon night, and a chance of showers to southern CT and eastern Long Island. Low temps will be in the 30s inland and 40s NYC metro/coast. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... To begin the period on Tuesday the CWA will be south of a warm front associated with low pressure across the Canadian - US border. Minimal precip chances appear the way to go during late Tuesday with the low levels being fairly dry and forcing being north of the region. As the upper level energy approaches from the west thinking that a slight chance POPs for northern sections appears prudent, as the SREF is a good compromise between the GFS and NAM guidance. Even though the sub-cloud dry layer will be a hindrance to precip chances, a nice spoke of upper level energy is progged to come through. The SREF guidance hints at this low precip probability, therefore slight chances feel prudent for far northwestern sections during at least parts of this timeframe. High pressure builds in from the north and west Wednesday afternoon through Thursday night. The high will settle over the region on Friday. Friday morning will most likely be the coolest morning of the region widespread across the region, especially if the winds lighten in time which the model consensus is indicating. There should be widespread 20s across rural locations Friday morning. Confidence is high for dry conditions to prevail later Wednesday right through Friday. Significant changes then take place into the weekend with the global models continuing to indicate cyclogenesis along the southeastern US coast for late in the period. There is fairly good agreement this far out in time on the track and overall intensity. However, the greatest uncertainty is with timing and this is centered around how quickly a confluence zone at 500 mb lifts north to begin next weekend. Some operational runs have lifted the system up sooner which would lead to clouds arriving quickly late Friday night into Saturday with rain as arriving as soon as Saturday afternoon, with the ECMWF 0z run from last night advertising this scenario. However, more operational runs than not and ensemble means indicating at least for right now that somewhat slower timing is more likely. Therefore it seems prudent at this time to delay much of the precip until Saturday night, but with the introduction of POPs as early as Saturday afternoon. If there are impacts from this system it appears that much of that will wait until the second half of the weekend. && .AVIATION /05Z MONDAY THROUGH FRIDAY/... A high pressure ridge shifts through the region today. VFR. NW-W winds under 10 kt through the morning push, then winds back more to the W, then finally shift SW in the afternoon at around 10 kt. Frequent gusts confined to KEWR/KTEB in the aftn which are more prone to gusts on a SW flow. Other sites may see occasional gusts. .OUTLOOK FOR 06Z TUESDAY THROUGH FRIDAY... .Monday night...VFR. .Tuesday...VFR. WSW winds G20KT. .Wednesday...VFR. NW winds G25KT. .Thursday...VFR. NW winds G20KT. .Friday...VFR. && .MARINE... All waters now under an SCA as gusts have dropped below gale force levels. As winds continue to diminish tonight, SCA conds on the non ocean waters should abate by midnight, then late tonight on the ocean. SCA conditions will return to the eastern ocean waters Tuesday afternoon, and expand westward across the ocean waters Tuesday night. SCA conditions may also take place for the eastern sound/bays for late Tuesday night into Wednesday morning. SCA conditions will then continue for much of the time through Wednesday for the eastern ocean waters. SCA conditions will then expand to the western ocean waters and possibly the Eastern Sound and the bays late Wednesday night into Thursday. High pressure then begins to approach the coastal waters with sub SCA conditions for all zones into Thursday night and Friday. && .HYDROLOGY... Dry through much of the period. Low pressure moving up the coast may bring rainfall on the order of an inch or so Saturday night into Sunday. && .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...None. NY...Frost Advisory until 9 AM EDT this morning for NYZ071-078>080- 177-179. Freeze Warning until 9 AM EDT this morning for NYZ081. NJ...Frost Advisory until 9 AM EDT this morning for NJZ006-106-108. MARINE...Small Craft Advisory until 6 AM EDT early this morning for ANZ350-353-355. && $$ AVIATION...JC

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