Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 252351 AFDOKX Area Forecast Discussion National Weather Service New York NY 751 PM EDT Wed Apr 25 2018 .SYNOPSIS... Low pressure over the Delmarva region will ride up across the area tonight, with a trailing cold front also passing through late. The low will move into New England on Thursday. Another low will move through on Friday, followed by a cold frontal passage late Saturday. High pressure will then be in control early to mid next week. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... PoPs were increased with this update for the early evening hours across LI and CT based on latest obs and trends. Chances for showers across the entire area drop off soon after this, then there should be a return of scattered to numerous showers later tonight as the weak sfc low moves across and takes a cold front with it, aided by lift from an accompanying negatively-tilted mid level shortwave trough. Meanwhile, with the pressure gradient relaxing tonight and abundant low level moisture remaining, expect a potential for dense fog before cold fropa, particularly across Long Island and southern CT, where both NARRE/HRRR time-lagged ensembles are flagging highest probabilities of vsby less than 1/4SM and 1SM, respectively. Have already issued a SPS for at least locally dense fog, and with light surface winds and a loss of turbulent mixing potential at the top of the mixed layer, may very well need to issue an advisory for some areas within the next hour or two. Iso/Sct thunderstorms should push north through SE CT early this evening. Winds aloft are weak, so not expecting any strong surface gusts with these storms. Fcst low temps tonight are on the warmer side of the MOS envelope, in the upper 40s and lower 50s. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/... Gusty WNW flow expected along with mostly sunny skies for the most part after the mid level shortwave passes through. A closed mid level low passing just to the north may help provide enough lift for sct-bkn Cu development in the afternoon, more so inland. With downslope flow and mixing to between 875-850 mb expect high temps to approach 70 in NE NJ and rise well into the 60s most elsewhere. Thu night should start mostly clear, then become mostly cloudy overnight as another low begins to approach from the SW. Low temps should be in the 40s and lower 50s per MOS blend. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... Models in good agreement with the closed low over the central Plains tracking eastward through the deep South on Thursday. This then lifts north toward the region Friday ahead of the next northern stream trough digging into the Mississippi River Valley on Thursday. At the surface, associated low pressure lifts northeast towards the region on Friday. This is a progressive system, with what looks like a quick hit of moderate rain (1/4 to 3/4 inch, locally 1 inch). Still uncertainty on where the axis of the heaviest rain will be, due to differences in track of low pressure and consequently placement of best lift/instability axis. Models then in general agreement with partial phasing of the southern energy and digging northern stream trough to develop a deep trough over the Great lakes into the NE US this weekend. Some spread in intensity/amplitude of this trough, but general consensus on its axis moving through Sunday. At the surface, an associated cold front moves through late Sat/Sat evening, with a couple of weak troughs moving through Sunday. Seasonable temps on Saturday in waa ahead of the front, dropping back down to a few degrees below seasonable on Sunday with cold pool and instability cloud cover. In its wake, deep layered ridging builds in for early next week, with potential for unseasonable warmth by midweek as ridging takes a Bermuda position. Temps moderate to seasonable on Monday and then above seasonable on Tuesday. Potential for the first real warm spell of the season mid to late week, with high temps in the 80s for NYC/NJ metro and Interior, and well into the 70s along the coast. && .AVIATION /00Z THURSDAY THROUGH MONDAY/... Low pressure tracks from the Mid-Atlantic coast this evening to the Canadian Maritime Provinces by early Thursday evening. IFR or less through at least 07Z. Light rain/drizzle continues through then, with some pockets of moderate rain possible. Outside of times when areas receive moderate rain, expect widespread fog to develop this evening. Conditions should improve to MVFR 8-11Z from W to E, then to VFR from 10-13Z from W to E as well. Light and variable winds into the early morning hours. Winds become W-WNW 8-11Z from W to E. Wind speeds increase to 10-15KT during the morning push, with gusts of 15-20KT developing towards the end of the morning push. Winds back to the WSW-SW at KJFK and KISP Thursday afternoon, remaining W to WNW elsewhere. Wind gusts should abate late Thursday afternoon/early Thursday evening. ...NY Metro Enhanced Aviation Weather Support... Detailed information, including hourly TAF wind component forecasts, can be found at: http:/ KJFK TAF Comments: High confidence IFR or less through 07Z. KLGA TAF Comments: High confidence IFR or less through 07Z. KEWR TAF Comments: High confidence IFR or less through 07Z. KTEB TAF Comments: High confidence IFR or less through 07Z. KHPN TAF Comments: High confidence IFR or less through 08Z. KISP TAF Comments: High confidence IFR or less through 08Z. .OUTLOOK FOR 00Z FRIDAY THROUGH MONDAY... .Thursday night...VFR. .Friday...MVFR or lower possible in rain. .Friday night-Saturday night. MVFR possible in isolated- scattered showers, otherwise VFR. .Sunday-Monday...VFR. W-NW winds G15-25KT possible. && .MARINE... SCA remains in effect for the ocean for elevated seas. SE winds were still gusting to 25 kt out by Montauk/Orient/Fisher`s Island, and should diminish there going into this evening. Marine dense fog advy issued for all waters for tonight as low pressure moves across and vsby lowers to less than 1 nm in most places. Cold fropa will shift winds to the W-NW and quickly scour out the fog late tonight into early thu morning. SCA seas likely continue on the ocean waters into Saturday night, possibly lingering into Sunday, due to lingering SE swells from the mid week system, and then added contribution of wind waves and southerly swells from a quick moving low on Friday and winds ahead and behind cold frontal passage Sat eve. Marginal SCA winds possible, mainly eastern waters Friday aft/eve on the eastern flank of low pressure. && .HYDROLOGY... Today`s rainfall has not been causing any hydrologic impact. QPF 1/4 to 3/4 inch possible Friday with a quick moving low. No hydrologic issues anticipated. && .EQUIPMENT... NYC NOAA Weather Radio Station KWO-35 (162.55 MHz) remains off the air. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...Dense Fog Advisory until 6 AM EDT Thursday for ANZ330-335-338- 340-345-350-353-355. Small Craft Advisory until 6 AM EDT Friday for ANZ350-353-355. && $$ SYNOPSIS...Goodman/NV NEAR TERM...JC/Goodman SHORT TERM...Goodman LONG TERM...NV AVIATION...Maloit MARINE...Goodman/NV HYDROLOGY...Goodman/NV EQUIPMENT... is the U.S. government's official web portal to all federal, state and local government web resources and services.