341
FXUS61 KOKX 210046
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
846 PM EDT Thu Mar 20 2025

.SYNOPSIS...
A cold front with developing low pressure will impact the region
tonight, and pass east on Friday. A high pressure ridge will
briefly slide in for late Friday into Friday night. Another cold
front will move through Saturday night. High pressure will
briefly return again on Sunday before a stronger frontal
system moves through on Monday. Weak high pressure will return
on Tuesday, with another low pressure system possible for
mid week.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
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A quick update to include a slight chance for thunder, mainly for the western half of the forecast area through midnight as lightning was observed across portions of NYC and points north and west. Current SPC mesoanalysis is showing MUCAPE of up to 1000 J/kg, so the instability is elevated. The forecast has been updated to include drizzle across most of the coastal areas. Anticipating areas of dense fog for the same areas, so a special weather statement has been issued to address this for the next few hours. The dense fog has persisted and become more widespread. A Dense Fog Advisory has been issued for Long Island and portions of southern Connecticut (excluding souther Fairfield) until 1 am Friday. As the cold front approaches and rain enters these areas, the dense fog is expected to improve somewhat. There is a chance that conditions improve prior to this time frame. Leading edge or rain should hold off in our CWA until about 00Z, and progress slowly east through 06Z. Areas from NYC north/west should see the most rainfall (1/2 to 3/4 inch) via best combo of forcing from the right rear quadrant of an upper level jet streak to the north, mid level positive cyclonic vorticity advection and frontogenesis moving directly across, and low level moisture transport from the S-SE. A weak sfc low developing directly over the region from 03Z-06Z will interrupt the low level moisture transport enough to keep rainfall mostly light across Long Island and S CT, though it may recover enough for far SE CT to see some moderate rainfall late tonight. As the rain moves in, vsby out east should gradually improve as well. As the developing low passes to the east, SE winds should quickly shift out of the NW late and gust as high as to 25-30 mph before daybreak. Low temps will be a fairly uniform upper 30s to lower 40s, warm enough to preclude any snowfall well north/west except maybe on the highest hills of far wrn Orange County.
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&& .SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/... A gusty NW flow will take hold and the air mass will dry out quickly on Fri as the pressure gradient tightens between the departing low and high pressure off to the west. Gusts 35-45 mph (just shy of wind advy criteria) likely from late morning into early afternoon as the blyr destabilizes and stronger winds mix down from aloft, and a few spots may see sustained winds 25-30 mph for a time as well. High temps on Fri close to a MOS blend, in the lower/mid 50s. Skies will be clear to start Fri night, then some high clouds will slide across late as the upper ridge axis slides across. Diminishing NW winds will become light as winds back SW and the blyr decouples, with good radiational cooling. Low temps should range from the lower 40s in NYC, to the 30s most elsewhere in the urban corridor and along the coast, to 25-30 inland. && .LONG TERM /SATURDAY THROUGH THURSDAY/... A weakening shortwave and surface cold front approach on Saturday and pass through late in the day into the evening. The system is moisture starved, with upstream shower activity likely weakening as it enters the area. Left in a slight chance of a shower NW of the city for Saturday afternoon/early evening. Mild and breezy conditions ahead of the cold front with quick shot of waa and deep mixing, giving way to glancing shot of polar air Sat night/Sun AM on gusty NW winds in wake of front. Highs for Saturday ranging from the mid 50s for south-facing coasts to the low 60s in parts of NE NJ. Brief ridging surface/aloft Sunday in wake of this system with temps running close to seasonable. 500mb trough and attendant surface low then move eastward through the western Great Lakes Region during Sunday night. Models have sped up the timing of this system in the past 24 hours. Lift ahead of an approaching warm front to the south interacts with increasing moisture for a chance of precip before midnight, but then becoming likely after midnight for roughly the western half of the forecast area. Thermal profiles would support a wintry mix for inland areas north of the city. Profiles then warm up for rain across the entire area during Monday. Although the rain could be briefly moderate to heavy with help from lift via a llj, rain impacts appear to minimal at this time. No wind impacts anticipated either as the llj looks to weak with a strong enough inversion below it. Lingering chances of showers for Monday night, then dry for Tuesday with weak high pressure. Models still disagree regarding the strength of a low center potentially passing through here sometime on Wednesday or Wednesday night. At the least, a cyclonic flow aloft with a surface trough will probably be around. Slight chance to chance (20-30%) of precip for this period. High pressure would then probably return for dry weather on Thursday. High temperatures Tuesday through Thursday at or slightly above normal. && .AVIATION /01Z FRIDAY THROUGH TUESDAY/... A cold front approaches this evening and crosses the terminals tonight. High pressure gradually builds in through Friday. Varying conditions across the region for the remainder of the afternoon. South facing coastal terminals will largely remain VLIFR to LIFR into early this evening with some brief improvement to IFR possible. Elsewhere, conditions will be IFR- VFR (mainly terminals away from the coast). Any terminals that are VFR are not expected to last long, especially with the moderate rain expected, which will limit visibility and come with lower ceilings. Expect LIFR-IFR after 00Z for these terminals. Rain will then overspread the terminals from west to east 00Z-05Z, latest for eastern terminals. The rain should largely end 06Z-09Z from west to east with conditions improving to VFR through day break Friday. VFR then prevails on Friday. SE winds 10-15 kt this afternoon with gusts up to 20 kt possible. Winds and gusts briefly weaken this evening before shifting to the WNW-NW with the frontal passage 06Z-10Z NW winds increase behind the front becoming 15-25 kt with G30-40kt on Friday. Winds and gusts should start weakening late Friday afternoon and into Friday evening. ...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty... Gusts of 15 to 20 kt possible through 06Z. Brief VFR possible at KSWF/KTEB thru 01Z. Thereafter, moderate rain is expected to lower conditions LIFR to IFR. Timing of lowering conditions this evening may be off by 1-2 hours. Timing of rain may be off by 1-2 hours this evening with conditions settling to IFR. .OUTLOOK FOR 00Z SATURDAY THROUGH TUESDAY... Friday night: VFR. NW winds 15-25g30-40kt in the afternoon. NW gusts 20-25kt in the evening, diminishing at night. Winds at some terminals may become light and variable. Saturday: VFR. Slight chance of a shower NW of NYC in the afternoon. SW gusts 20-25kt in the afternoon, becoming W/NW in the evening. Sunday: VFR. NW gusts 15-20kt. Sunday Night and Monday: Becoming IFR with rain. Possible onset as snow for KSWF. S gusts 15-20kt near the coast on Monday. Tuesday: VFR. Detailed information, including hourly TAF wind component forecasts, can be found at: https:/www.weather.gov/zny/n90 && .MARINE... Marine dense fog advy issued for all waters til 2 AM as vsby once again lowers throughout to less than 1 nm in a maritime air mass. As a frontal system moves across tonight, rain should scour out the fog with vsbys improving. SCA remains in effect for the ocean waters for tonight as SE flow increases to 20 kt and pushes current 4-5 ft seas to 5-7 ft late tonight. The gale warning for daytime Fri also remains in effect, with gusts up to 35 kt expected on all waters mainly from late morning into early afternoon in strong NW flow. Sub advisory conditions for Saturday morning, then winds and seas build in a SW flow. Advisory conditions mainly on the ocean Saturday afternoon through Sunday morning. Elsewhere, a few gusts to 25 kt possible during Saturday night. Sub-SCA conds for Sunday afternoon and night as a high pressure ridge shifts through. The next potential for SCA conds is then on Monday ahead of a frontal system, particularly on the ocean. Elevated seas may linger through a good portion of Tuesday. && .FIRE WEATHER... Strong NW flow gusting to 35-45 mph and RH quickly lowering to 25-30 percent may present an elevated risk of fire growth/spread daytime Fri. A wetting rain of 1/2 to 3/4 inch expected from NYC north/west tonight and about 1/4 inch to the east, so fuel moisture and drying are uncertain, and may lessen the risk. In collab with NY State land managers have decided to hold off on any product issuance and re-evaluate depending on how much rain fall tonight and how quickly conds dry out daytime Fri. && .HYDROLOGY... Rainfall tonight should be from 1/2 to 3/4 inch from NYC north/west, with lesser amts to the east, mostly around 1/4 inch but possibly as much as 1/2 inch across far SE CT. No hydrologic impacts expected. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...Dense Fog Advisory until 1 AM EDT Friday for CTZ010>012. NY...Dense Fog Advisory until 1 AM EDT Friday for NYZ078>081-177- 179. NJ...None. MARINE...Dense Fog Advisory until 2 AM EDT Friday for ANZ331-332-335- 338-340-345-350-353-355. Gale Warning from 6 AM to 6 PM EDT Friday for ANZ331-332-335- 338-340-345-350-353-355. Small Craft Advisory until 6 AM EDT Friday for ANZ350-353-355. && $$ SYNOPSIS...JC/BG NEAR TERM...BG/JP SHORT TERM...BG LONG TERM...JC AVIATION...JP MARINE...JC/BG FIRE WEATHER... HYDROLOGY...JC/BG