Area Forecast Discussion
Issued by NWS Upton, NY

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600 FXUS61 KOKX 200223 AFDOKX Area Forecast Discussion National Weather Service New York NY 923 PM EST Sun Nov 19 2017 .SYNOPSIS...
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High pressure builds southwest of the region tonight, eventually offshore Monday into Monday night. High pressure departs to the east Tuesday, followed by a cold front Wednesday. Another high builds late week before next system impacts the area next weekend.
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&& .NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
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Upper trough axis will swing across the region tonight. Vorticity max within the trough could enhance lift just enough to produce an isolated rain or snow shower, mainly N and W of NYC. Have left PoP as slight chance, but adjusted to better match latest trends in observations. At the surface, high pressure will build to the southwest of the region. Winds will remain gusty out of the WNW, but will be lowering in magnitude as mixing weakens through the night. Lows were a blend of MAV/ECS as MET numbers seemed too high.
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&& .SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/... The region is more in between the polar and subtropical upper level jets. In the mid levels, more of a ridging trend will take shape. At the surface, high pressure moves eastward towards the Carolina coastline Monday and then off into the Atlantic Monday night. Dry conditions are expected through the period. Monday is expected to be cooler, about 5 degrees below normal with more gusty WNW flow, mitigating sensible heat transfer. For Monday night, winds are expected to lower with gusts diminishing. With mostly clear conditions, expect radiational cooling to result in a more typical vast range of lows between the urban heat island and inland rural sections. && .LONG TERM /TUESDAY THROUGH SUNDAY/... Better model agreement today in this active and progressive pattern. Aloft, active northern stream expected as multiple shortwaves pass during this time frame. Looks like the operational GFS has now trended much closer to other global models with handling of mid week trough. Latest GFS is notably weaker with trough along the Gulf states Wednesday, and is thus not developing a wave of low pressure off the coast Thursday, like it did 24 hours ago. As such, looks like WAA on the backside of the high will provide a mild/breezy day Tuesday, likely the warmest of this time frame. Plenty of sun will give way to increasing clouds as high level moisture approaches, along with moisture advecting from the south in the lower and mid levels. Nam/wrf seems to be the most aggressive in outputting precip ahead of the cold front. Still looks like best chance for rain will be east of NYC late Tuesday into Wednesday. Dry thereafter as ridge builds. A cold front passes with little fanfare Friday, then next shortwave approaches this weekend. Colder air advects in behind a front by Sunday. Minimal pops warranted next weekend with this system. Above normal temps Tuesday in WAA regime, then temps tumble to just below normal from late Wednesday through Sunday. Looks like a cool day Thursday, with a slight rebound Friday and Saturday before falling back again Sunday. A model/mos blend followed which is in line with latest WPC numbers. && .AVIATION /03Z MONDAY THROUGH FRIDAY/...
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VFR as high pressure builds in through Monday. WNW winds continue tonight. Gusts 20-25 kt may be intermittent at times. An isolated rain or snow shower possible mainly NW of NYC terminals. Gusty W-WNW winds around 25 kt expected on Monday. .OUTLOOK FOR 00Z TUESDAY THROUGH FRIDAY... .Tuesday...Mainly VFR. MVFR possible late Tuesday night in showers. SW winds G20-25KT. .Wednesday...MVFR possible with showers during the day. VFR at night. NW winds G20KT in the afternoon/evening. .Thursday-Friday...VFR.
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&& .MARINE... Steep pressure gradient remains tonight, so still expecting gales for all waters tonight. Wind gusts closer to 35 kt are forecast through the night as boundary layer flow decreases. The boundary layer flow further decreases Monday with gales becoming marginal. SCA will then be more likely across the waters on Monday especially the ocean with high seas of 5-8 feet continuing. SCA conditions still probable for the ocean Monday night while non-ocean waters will see an eventual decrease in wind gusts to below SCA late. Winds increase in SW flow Tuesday. A few locations could approach gale force or 35 kt. Winds then diminish somewhat Tuesday night ahead of a cold front. Low pressure passes southeast of the waters Wednesday as the cold front crosses the area. NW flow Wed night back to the west and diminishes further Thursday as a ridge of high pressure builds. A cold front passes Friday, with the ridge building back yet again. && .HYDROLOGY... No hydrologic problems are anticipated. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...Gale Warning until 6 AM EST Monday for ANZ330-335-338-340-345- 350-353-355. && $$ SYNOPSIS...JM/PW NEAR TERM...JM/DS SHORT TERM...JM LONG TERM...PW AVIATION...DS MARINE...JM/PW HYDROLOGY...JM/PW

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