FXUS61 KOKX 191927 AFDOKX Area Forecast Discussion National Weather Service New York NY 327 PM EDT Wed Mar 19 2025 .SYNOPSIS... High pressure shifts offshore tonight ahead of a low pressure system that will slowly approach from the west. Low pressure and the attendant cold front move through the area Thursday night with high pressure briefly following for Friday into Saturday before a weak area of low pressure passes through Saturday night. High pressure then returns Sunday, with another frontal system expected to move through early next week. && .NEAR TERM /THROUGH TONIGHT/... Satellite imagery shows an extensive area of fog and stratus offshore, confirmed by observations across eastern Massachusetts. Overnight, the combination of subsidence from high pressure aloft, diurnal cooling, and winds veering to the ESE will allow both the development and the WNW progression of stratus and fog. Deepening low level moisture and at least minimal vertical ascent may additionally support patchy drizzle, primarily for areas closer to the coast. Minimum temperatures will be about 10 degrees above climatological normals, ranging from the mid to upper 30s inland, to mid 40s across NYC. && .SHORT TERM /THURSDAY THROUGH FRIDAY/... Increased cloud cover, fog, and drizzle may persist into the morning beneath the subsidence inversion as low level flow generally remains onshore. High temperatures will be cooler than the previous few days, generally in the upper 40s to 50s closer to the coast and closer to 60 across New Jersey and the Lower Hudson Valley. As the day progresses, phasing upper systems will strengthen meridional flow aloft, allowing for moisture advection ahead of an approaching cold front. Although precipitable water values will approach the 90th percentile for time of year, the progressive nature of the front will generally keep rainfall accumulations under an inch Thursday night. Cold advection following the departing front may lead to a brief period of snow across interior portions of the Lower Hudson Valley, but probabilities of occurrence remain at or below about 10 percent. Would not expect much if any accumulation if snow does occur. Following the front, flow strengthens between the departing system and building high pressure allowing for a blustery day. Although highs will be close to climatological normals in the upper 40s to lower 50s across the area, breezy winds will make temperatures feel much cooler. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... High pressure builds in Friday night and weakens during Saturday as an upper shortwave and surface trough shift through during the afternoon to evening hours. Slight (20%) chance of a shower for the NW half of the forecast area during Saturday afternoon, otherwise dry Friday night through Saturday night. Above normal high temperatures for Saturday, mostly 55-60. A cooler air mass follows for Sunday as high pressure builds in from the NW. Highs near normal at around 50. 500mb trough and attendant surface low then move through the western Great Lakes Region during Sunday night. Lift ahead of an approaching warm front to the south interacts with increasing moisture for a chance of rain after midnight. For areas north of the city, thermal profiles would support snow or a wintry mix. Rain is then likely (70% chance) on Monday and Monday night with the warm front lifting through the region during the day, followed by a cold front at night. Impacts so far appear to be very limited as the convective/heavy rain/wind threats are minimal. Weak high pressure is left in the wake of the storm system for Tuesday, and it remains weak on Wednesday with another 500mb trough moving in. Will go with a dry forecast for Tuesday, but there's a slight chance for showers on Wednesday with cyclonic flow aloft and enough mid-level moisture. The sub-cloud layer may however be too dry to support anything reaching the ground. && .AVIATION /19Z WEDNESDAY THROUGH MONDAY/... High pressure gradually moves off the New England coast tonight. A cold front approaches on Thursday. VFR through 22z. Low stratus and fog will likely begin moving in from the E and SE this evening generally between 00z and 03z at most terminals, taking longest to reach KSWF (04-07z). Flight categories are expected to fall to IFR and then LIFR once the stratus/fog overspread the terminals. LIFR likely persists through day break with gradual improvement to IFR and then MVFR Thursday morning. Some patchy drizzle is also possible overnight and early Thursday morning. Mainly MVFR conditions with local IFR expected Thursday afternoon with a chance of improvement to VFR. SE-S winds 10 kt or less will continue through the rest of the afternoon. Winds will weaken this evening and back towards the E, becoming light and variable outside of the NYC metro terminals. SE winds increase again Thursday morning, with gusts around 20 kt possible, mainly in the afternoon. ...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty... Amendments likely for timing of IFR/LIFR this evening. Visibilities could lower to 1/2SM several hours faster than currently indicated overnight. Timing of improving ceilings/visibilities Thursday morning may be off by 1-3 hours. .OUTLOOK FOR 18Z THURSDAY THROUGH MONDAY... Thursday Afternoon: MVFR-IFR possible. SE winds G20kt. Thursday night: IFR likely in rain. Precip could mix with snow late at KSWF. NW winds G20-25kt late from the NYC metros north/west. Friday: Chance showers and MVFR early, becoming VFR. NW winds G30- 40kt morning and afternoon. NW gusts 20-25 kt in the evening. Saturday: Mainly VFR. Slight chance showers NW of NYC. SW winds G20kt in the afternoon at the NYC metros. Sunday: VFR. NW winds G20kt. Monday: IFR with rain likely. S-SW winds G20 kt possible. Detailed information, including hourly TAF wind component forecasts, can be found at: https:/www.weather.gov/zny/n90 && .MARINE... Sub small craft conditions will persist overnight before ocean seas begin to gradually increase beginning Thursday morning. Small craft seas should prevail by afternoon with a SE wind around 15 kts late in the day and evening. Low pressure and its associated frontal system pass through Thursday night with an abrupt shift in winds that will gust to gales from the NW into Friday. Winds and seas then subside through Friday night with advisory conditions, but perhaps a gust or two to gale force across the eastern ocean waters early on. Sub-advisory conditions otherwise prevail by Saturday morning, however increasing winds from the SW probably push ocean seas back up over 5 ft Saturday afternoon into Saturday night. A few gusts to 25 kt will also be possible for some of the non-ocean waters Saturday night. Winds then subside once again on Sunday with sub-advisory conditions Sunday afternoon through Monday morning. Winds increase Monday afternoon with SCA conds likely at least on the ocean. && .HYDROLOGY... At this time no hydrologic impacts are expected throughout the forecast period. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...Gale Watch from Friday morning through Friday afternoon for ANZ331-332-335-338-340-345-350-353-355. Small Craft Advisory from 8 AM Thursday to 6 AM EDT Friday for ANZ350-353-355. && $$ SYNOPSIS...JC/MD NEAR TERM...MD SHORT TERM...MD LONG TERM...JC AVIATION...DS MARINE...JC/MD HYDROLOGY...JC/MD