Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 240742 AFDOKX Area Forecast Discussion National Weather Service New York NY 342 AM EDT Sat Mar 24 2018 .SYNOPSIS... High pressure builds down from southeastern Canada through Monday night, then remains anchored along the Eastern Seaboard of the United States into the middle of next week. This high then slowly slides offshore, as a slow moving cold front approaches from the west through Thursday night. The cold front then crosses the area on Friday. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... Northern stream shortwave ridging crosses the area today, so it should be dry due to subsidence under the ridge. However, cannot completely rule out a stray sprinkle/flurry over mainly eastern zones this morning before the ridge axis moves over the area. As the ridge axis passes to the east this afternoon, will see some increase in cloud cover ahead of the next spoke of vorticity rotating around the closed low over S Quebec. Highs today should be a few degrees above normal, mainly in the mid to upper 40s. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/... The main axis of the eastern trough pushes south into the region by late tonight, then to the south of the area Sunday morning, followed by a secondary trough axis Sunday afternoon. Associated forcing warrants pops for isolated-scattered snow showers late tonight, scattered snow showers Sunday morning, then isolated-scattered rain and snow showers Sunday afternoon. Generally any accumulation should be very light, only a few tenths of an inch. However cannot completely rule out an isolated convective burst of snow producing localized amounts of around 1 inch. Also, given the steep low level lapse rates, cannot rule out graupel or strong gusty winds from any stronger shower as well. Lows tonight should be from a few to around 5 degrees below normal. Highs on Sunday should run around 10 degrees below normal. Gusty NE winds will cause wind chills around 30 Sunday afternoon as well. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... Deep layered ridging builds in Sunday night-Tuesday. Other than maybe some lingering snow showers over far eastern zones early Sunday evening, it should be dry Sunday night-Tuesday. Other than decreasing clouds Sunday night, it should be mainly clear through Tuesday as well. Temperatures will run around 10 degrees below normal Sunday night-Monday night and around 5 degrees below normal on Tuesday. The ridge axis slowly slides offshore Tuesday night and Wednesday as a northern stream trough builds into SE Canada, flattening the top of the ridge. At a minimum will see an increase in cloud cover starting Tuesday night. There is some question in how far east precipitation pushes on Wednesday. For now have limited pops to slight chance over the western 1/5 of the CWA. Could possibly some snow mixed with any rain that does occur Wednesday morning. Ridging then builds in from the S, with a return of the Bahamas ridge featured early in winter. This will help keep at bay a full latitude that slowly slides from the Plains Wednesday night to the Ohio Valley on Friday. However, since the area will be on the NW periphery of this ridge, it will be subject to the influence of shortwaves running ahead of the main trough. These shortwaves could bring isolated-scattered showers to the region from Wednesday night-Friday, with the best chance Thursday night and Friday. Temperatures Tuesday night-Friday should run near to slightly above normal. && .AVIATION /07Z SATURDAY THROUGH WEDNESDAY/... Strong high pressure based in Southeast Canada slowly builds southward. With one surface trough south of the region, another one will move across Saturday afternoon into Saturday night. VFR through the TAF period. Ceilings near 4-5kft will likely develop this afternoon. NW flow today, veering to the ne tngt. Ocnl gusts to around 20kt thru 8z, mainly at the nyc arpts, then speeds generally blw 15kt thru the remainder of the taf period. .OUTLOOK FOR 06Z SATURDAY THROUGH WEDNESDAY... .Saturday night-Sunday...Mainly VFR. Isolated rain/snow showers with MVFR conditions. NE winds G15-20KT. Gusts to 25 kt possible Sunday. .Sunday night-Monday...VFR. NE winds G15-20KT, mainly at the coastal terminals. .Tuesday-Wednesday...Mainly VFR. && .MARINE... NW winds will remain below 25 kt today. The flow becomes NE behind a cold front tonight, with winds picking up into Sun. The brisk NE winds will then continue into Mon. The strongest flow will be across the eastern waters and ocean. A Small Craft Advisory (SCA) has therefore been issued for Sunday and Sunday Night for these areas. The SCA may need to be extended through Mon. The prolonged NE flow will keep seas at or above 5ft on the ocean through at least Wed. It is possible that seas stay at SCA levels for the rest of the week. && .HYDROLOGY... Rapid snow melt will continue into the weekend as high temps climb into the 40s. No hydrologic problems are anticipated through Thursday. && .EQUIPMENT... NYC NOAA Weather Radio Station KWO-35 (162.55 MHz) is off the air for an extended period of time. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...Small Craft Advisory from 6 AM Sunday to 6 AM EDT Monday for ANZ330-340-345-350-353-355. && $$ SYNOPSIS...Maloit NEAR TERM...Maloit SHORT TERM...Maloit LONG TERM...Maloit AVIATION...JMC/JM MARINE...JMC HYDROLOGY...Maloit EQUIPMENT... is the U.S. government's official web portal to all federal, state and local government web resources and services.