Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 230134 AFDOKX Area Forecast Discussion National Weather Service New York NY 934 PM EDT Sat Oct 22 2016 .SYNOPSIS... Deepening low pressure moves through Maine and southeastern Canada through Sunday. Another cold front associated with the low moves through the area late Sunday night into early Monday morning. Canadian high pressure builds behind the front Monday through Wednesday. Low pressure approaches and moves across the area Thursday into Friday. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... Deepening low pressure over central Maine will continue to move north into southeastern Canada overnight, reaching as low as 978 MB by Sunday morning. Trends show drier air advecting in, and any lingering rain should lift north of the area as the night progresses. Expected rain to end around 06-08Z as the last of the vorts rotates through the trough. Weak cold advection also continues and with low level winds to around 40 to 50 KTs. Still expect some of these winds to mix to the surface, although sfc cooling should prevent frequent gusts of 40 kt. With the best mixing through this evening there is still the potential for gusts and perhaps some sustained winds to reach wind advisory criteria. Largest pressure rises continue across cstl zones. As such, will maintain the advisory for Nassau county and the NYC zones until 04z, and continue through 10Z for the remainder of the zones that were in the advisory, mainly eastern zones. Temps will fall slowly or remain steady in this mixed environment. Weak CAA and some clearing will allow for temp falls of a few degrees later tonight. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/... Sunday is expected to be dry with the upper trough remaining and the upper low beginning to cut off. Gusty winds remain however low level winds will be diminishing and cold advection shuts off 09Z to 12z and weak warm advection starts. Winds early in the morning will be the strongest and an occasional gust may approach 45 MPH across the eastern zones before winds diminish. A northern stream shortwave moves quickly through the northern tier of the United States and moves into the upper trough Sunday evening. A re enforcing cold front and the shortwave then move through 06Z to 12Z Monday with a chance of showers. With minimal lift will have only chance probabilities. && .LONG TERM /MONDAY THROUGH SATURDAY/... Upper trough remains across the northeastern portion of the country early to mid week, as ridge to the west eventually flattens per global models. Differences arrive with handling of shortwave that develops across the upper mid west as it traverses east late in the week. At the surface, low pressure associated with lingering upper trough moves slowly across eastern Canada, as high pressure builds out of central Canada and into the Great Lakes Region through mid week. The high briefly slides across the area Thursday before giving way to low pressure Thursday and Friday. Frontal boundaries, first warm front followed by the cold front, impact the area from late Thursday, into Friday. For Saturday, forecast becomes less clear. A possible weak frontal boundary may move through Saturday, but confidence in this remains low at this time. Generally dry conditions are anticipated Monday through Wednesday night as initial shortwave and front clears the area, and high pressure slowly builds. Cyclonic flow could result in more cloud cover each day, especially into New England Tuesday and possibly Wednesday. The best chance for rain looks to be late Thursday, Thursday night into Friday. ECMWF slower with upstream system compared to usually quicker GFS. Temperatures will initially average right around normal Monday. Then cooler canadian air settles in and expect readings to remain below normal Tuesday and Wednesday. Temperatures slowly moderate closer to normal Thursday through Saturday. && .AVIATION /02Z SUNDAY THROUGH THURSDAY/...
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Strong low pressure will move slowly north into Quebec over the next 24 hours. As it does so, any lingering light rain and MVFR cigs, mainly at/near KGON and KSWF, will give way to VFR conditions overnight. W winds 15-20 kt with gusts 25-30 kt, with an occasional higher gusts 30-35 kt, are still ongoing this evening. These winds should diminish a few kt overnight, and the resume by 13Z-14Z Sunday. These winds should diminish during Sunday afternoon, with exact timing and degree still a little uncertain. .Outlook for 00Z Monday through Thursday... .Sunday night-Monday Morning...Mainly VFR. Chance of showers after midnight. .Monday Afternoon-Tuesday...VFR. NW winds G20-25KT. .Wednesday-Thursday...VFR.
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&& .MARINE... Deepening low pressure continues to track slowly to the north across Maine and into southeastern Canada through Sunday night. Winds and gusts have increased and gale conditions are observed this evening. As the low continues to deepen and with cold advection continuing into Sunday morning, gale conditions will continue. The winds and gusts will begin to gradually diminish late Sunday morning into Sunday afternoon. Gale conditions may end by Sunday afternoon across NY harbor and the western Long Island Sound. Will leave gale warning posted across all the forecast waters through Sunday. Gusty NW winds 25-30 kt are likely Monday through Tuesday as the pressure gradient remains rather tight. Winds and seas are forecast to decrease on Wednesday and into Thursday as high pressure builds. && .HYDROLOGY... Little additional QPF is expected for the remainder of the evening. Dry late tonight through Sunday evening. For Sunday night, around a tenth of an inch of rainfall is possible. Rainfall amounts of 1/2 inch or more are possible Thursday into Friday. No hydrologic impacts are anticipated. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...Wind Advisory until 6 AM EDT Sunday for CTZ007-008-011-012. NY...Wind Advisory until 6 AM EDT Sunday for NYZ078>081. Wind Advisory until midnight EDT tonight for NYZ072>075- 176>179. NJ...None. MARINE...Gale Warning until 6 PM EDT Sunday for ANZ330-335-338-340-345- 350-353-355. && $$ is the U.S. government's official web portal to all federal, state and local government web resources and services.