Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 070308 AFDOKX Area Forecast Discussion National Weather Service New York NY 1008 PM EST Fri Dec 6 2019 .SYNOPSIS... A cold front passes through the area this evening. High pressure will follow for Saturday and then build offshore on Sunday. A slow moving frontal system will affect the area through mid week, followed by arctic high pressure late in the week. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... Cold front continues to cross the western half of the CWA this evening and will push south overnight. Northern stream shortwave passes across New England tonight, and associated clipper system departs east of New England as the front moves to the east. Gusts of 20-30 mph likely behind the front, will usher in a Canadian airmass of 1030mb with slightly below seasonable temps. Generally mid 20s interior, upper 20s to lower 30s city/coast. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY/... Northern stream trough amplifies over the region Saturday, sliding east Saturday Night, with weak upper ridging building in for Sunday. Mostly sunny, dry and unseasonably cool conditions Saturday as Canadian high pressure builds overhead. High generally in the lower 30s Interior, and mid to upper 30s city/coast. Occasional NW gusts to 15 to 20 mph possible. Potential for strong radiational cooling conds Saturday Night with high pressure overhead. Lows well down into the lower teens across Interior, particularly where snowpack lingers, as well as pine barrens of LI. Otherwise, lows generally in the upper teens to lower 20s coast, mid 20`s city. High pressure slides offshore Sunday, with developing return flow and temperatures moderating a bit. Another dry day, with increasing high clouds filtering in with PAC flow. Highs generally upper 30s to lower 40s, but still a few degrees below seasonable. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... Large upper trough moves out of the west and across the middle of the country early next week, with good model consensus. The trough axis passes Thursday as it lifts northeastward, with rising heights by late in the week. At the surface, high pressure continues to move well to the east as waves of low pressure ride along a front over the mid west to the northeast. As these waves of low pressure ride along the front toward the Great Lakes region, a warm front lifts north of the area Monday. Rain chances increase Sunday night into Monday ahead of this warm front, and in strong WAA and increasing lift, along with plenty of sub tropical moisture. The cold front will approach the area Tuesday, and model consensus tracks the front across the area Tuesday night. The front moves slowly east Wednesday, with a lingering sfc trough possibly passing through Wednesday late in the day or at night. High pressure then builds behind, ushering in the coldest air of the season. As for sensible weather, showers on Tuesday and Tuesday night taper off early Wednesday, with some difference in the models with amount of post frontal precip lingering ahead of slow moving trough Wednesday. Depending on amount of precip behind the front, enough cold air could result in a period of wintry weather Wednesday morning. Gusty southerly winds will result in mild temperatures Sunday night (rising) and Monday. This mild air remains in placed ahead of the cold front Monday night and Tuesday, before temperatures fall back Tuesday night and Wednesday. Very cold air will settle in Wednesday night and Thursday, with temps likely remain below freezing. A slight warmup is expected by Friday as the high passes east. Total QPF amounts of 1-3 inches is expected with this long duration event, Sunday night-Wednesday morning. 6Z GEFS plumes show this spread, with mean right around 1 1/2 inches. && .AVIATION /03Z SATURDAY THROUGH WEDNESDAY/... Predominately VFR conditions expected through the forecast period. 5kft ceilings will give way to mostly clear skies following a cold front pushing south through the region late this evening during the overnight hours. Fairly high confidence in winds 10-15 G20-25kt this evening but may be a brief lull as the front passes through. Timing of fropa roughly 01Z NYC metros and 01Z-02Z east, with winds shifting WNW at first and then right of 310 mag toward midnight. .OUTLOOK FOR 03Z SATURDAY THROUGH WEDNESDAY... .Saturday and Sunday...VFR. .Sunday night and Monday...Rain showers likely with MVFR or lower conditions. .Tuesday...MVFR or IFR in rain, with conditions improving late at night. .Wednesday...VFR. NW G30kt possible. && .MARINE... A Gale warning remains in effect for the ocean waters with SCA conditions elsewhere into tonight with winds continuing to ramp up ahead of an approaching cold front. The cold front passes through the waters this evening. Gusts of 30 to 35 kt diminish to below SCA by daybreak Saturday as high pressure builds in from the west. SCA waves may linger a bit on the eastern ocean waters Saturday morning, before falling below SCA. Otherwise, sub-SCA conds through Sunday as high pressure moves overhead. Southerly winds increase Sunday night into Monday as the pressure gradient tightens between the departing high to the east and cold front to the west. As the front draws closer, the southerly flow will increase late Monday into Monday night, with gusts 25-35 kt or near gale force for eastern waters. Winds diminish somewhat as the front nears and passes Tuesday, Tuesday night and possibly into Wednesday. Winds should increase as they turn to the west/northwest late Wednesday. Seas will builds Sunday night and Monday in strengthening southerly flow. Seas will subside slowly Tuesday-Wednesday as the cold front passes and winds diminish somewhat. && .HYDROLOGY... No significant liquid equivalent is forecast through Sunday. A significant long duration rainfall event is expected later Sunday night, continuing through Tuesday night. There will be some lulls in the precipitation, but the rain could be heavy at times Monday and Monday night, and again later Tuesday. The long duration of the event should preclude widespread flooding. Nuisance/poor drainage flooding is the most likely outcome. && .EQUIPMENT... NYC NOAA Weather Radio Station KWO35 (162.55 MHz) is still operating at reduced power. The KOKX WSR-88D radar will be out of service until approximately 12/7 due to the refurbishment of the transmitter. This work is part of the NEXRAD Service Life Extension Program. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...Small Craft Advisory until 3 AM EST Saturday for ANZ330-335- 338-340-345. Small Craft Advisory until 7 AM EST Saturday for ANZ350-353- 355. && $$ SYNOPSIS...NV/PW NEAR TERM...NV/PW SHORT TERM...DJ/16 LONG TERM...PW AVIATION...DJ/16 MARINE...NV/PW HYDROLOGY...NV/PW EQUIPMENT... is the U.S. government's official web portal to all federal, state and local government web resources and services.