Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 252049 AFDOKX Area Forecast Discussion National Weather Service New York NY 349 PM EST Thu Feb 25 2021 .SYNOPSIS... High pressure builds in for Friday. A frontal system impacts the area Friday night and Saturday. Another frontal system moves through the region Sunday into Monday. High pressure briefly returns Tuesday. Another frontal system may impact the area Wednesday and Thursday. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... Winds continue to decrease this eve as a 1031 high over the Midwest builds ewd. The combination of a weakening pres grad and diurnal cooling should allow winds to become lgt aft dark, especially away from the immediate shore. Mainly clr skies will allow for good radiational cooling. The vis stlt shows much of the snow is gone for LI and NYC, with more elsewhere. The NBM looked to reflect that decently in the overnight low temp field, so the guidance was accepted with minimal changes made. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/... Strong subsidence on Fri so sunny skies can be expected. Winds lgt with the high building right over the cwa. The NBM was used for temps which was a few degrees blw climo. The high builds offshore Fri ngt with a warm front passing n of the area. The models are in good agreement with pcpn breaking out in the waa pattern between 6-9Z across the swrn portion of the area, and 9- 12Z elsewhere. The cold air is progged to erode quickly, but it does look likely to hold in long enough for at least a wintry mix at the onset across the interior. Mainly snow and sleet changing over to rain is expected, but across some portions of the interior, there could be a bit of fzra as well where the llvl cold air is locked in a bit longer. The favored area for this is across nwrn Orange county, and a hundredth of icing has been added to the fcst. Any period of icing is expected to be brief attm, with the pattern not conducive to significant cad. The 15Z sref was used for pops and timing, and the NBM along with CONSALL was used for temps, which should rise overnight. && .LONG TERM /SATURDAY THROUGH THURSDAY/... A weak low center embedded within a broad area of low pressure shifts through on Saturday with rain likely. Mixed PCPN for the first few hours of the morning NW of the city before thermal profiles warm up for all rain by noontime. Total snowfall is expected to be under an inch. Rain should end by sunset for most places, then weak ridging supports dry weather Saturday night. Another weak low center then approaches us on Sunday with rain likely, and if it begins early enough, locations well NW of the city could see it briefly mix with sleet due to wet-bulbing. Models have the low passing just offshore Sunday evening with lingering rain chances, then a surface trough moves in with moisture convergence, maintaining chances of rain overnight. Drying of the atmospheric column occurs on Monday with a westerly flow setting up ahead of an approaching cold front. The cold front passes through dry, and it becomes breezy in the afternoon. An upper trough axis and shortwave then pass through Monday night. Not much moisture depicted by the models, but still included a chance of flurries during the period. Remaining breezy as well. Deep-layered ridging then occurs for Tuesday with dry conditions. ECMWF and GFSv16, and to a lesser degree GDPS, then show a broad area of low pressure that could bring mainly rain to the forecast area Wednesday-Thursday. Will go with only chance PoPs for now for this period. High temperatures will be in the 40s through the long term forecast, with the exception of Tuesday when it will be mostly 35-40. && .AVIATION /21Z THURSDAY THROUGH TUESDAY/... VFR all terminals as high pressure builds in. The high moves overhead late tonight into Friday morning and offshore late Friday morning into Friday afternoon. Winds are WNW/NW 10-15 kt. Gusts have generally diminished, but occasional gusts of 20-25 kt are still possible through 00Z. Winds become less than 10 kt overnight tonight as the center of high pressure moves overhead. They may actually become light and variable, especially some of the outlying terminals. Winds then shift toward the S late Friday morning into the early afternoon. ...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty... Amendments possible if gusts continue longer than forecast. .OUTLOOK FOR 18Z FRIDAY THROUGH TUESDAY... .Friday...VFR. .Saturday...MVFR or lower with rain. A wintry mix possible at the onset, mainly for KSWF. .Sunday...Chance of rain and MVFR. .Monday...Strong NW winds possible behind a cold front. .Tuesday...VFR. NW winds gusts 20-25 kt possible. Detailed information, including hourly TAF wind component forecasts, can be found at: http:/www.weather.gov/zny/n90 && .MARINE... Winds and seas have come down this aftn, and the sca will be canceled for all waters. Winds and seas are then expected to remain blw sca lvls thru Fri ngt. Winds and seas increase to advisory levels on Saturday ahead of an approaching low pressure system, with seas remaining elevated due to a lingering swell in the storm`s wake. Elsewhere, gusts to 25 kt will be possible primarily over the eastern Sound and Bays on Saturday. Seas up to 5 ft may still linger on the ocean through Sunday night with a weak low center passing through the area waters. A cold front then passes through on Monday with cold air advection perhaps strong enough to create gale force gusts on some of the waters - if not at least SCA conditions through Tuesday morning. High pressure then settles in with more tranquil conditions by the end of Tuesday. && .HYDROLOGY... No hydrologic impacts are anticipated through Wednesday. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...JMC/JC NEAR TERM...JMC SHORT TERM...JMC LONG TERM...JC AVIATION...JP MARINE...JMC/JC HYDROLOGY...JMC/JC

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