FXUS61 KOKX 041950 AFDOKX Area Forecast Discussion National Weather Service New York NY 350 PM EDT Fri Apr 4 2025 .SYNOPSIS... High pressure passes overhead tonight. A warm front approaches the area on Saturday and may lift to the north Saturday night. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... Heights rise aloft slightly tonight as ridging builds into the area. A very strong ~190kt anticyclonically curved upper level jet streak will build well north of the area in southeastern Canada. At the surface, the cold front that passed through this morning will stall offshore. High pressure centered to our north will move through and offshore tonight. With a northwesterly flow, some drier air is filtering into the area. Clouds continue to gradually thin and clear from north to south. The clearing will not last too long as mid and upper level clouds increase around midnight with a wave of low pressure approaching from the south west. So even though winds will be light tonight, the cloud cover will not allow for efficient radiational cooling. The winds also turn easterly as the high shifts offshore, which will start to bring in an increase in low level moisture. Stuck with NBM for low temperatures which gave 40s everywhere. With some lift ahead of the approaching wave and associated warm front, some light rain will be possible, mainly for NYC north and west after midnight. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/... The warm front continues its approach on Saturday and may lift north of the area Saturday night. There is some uncertainty across the latest guidance on whether it will lift completely through or stall somewhere over the area. Regardless, with the front at least nearby, wet conditions are expected. There is also some disagreement across the CAMs on exact timing of rain. The HRRR is the fastest, bringing widespread rain in after 8AM. If this verifies, the current forecast may be a few hours too slow. Much of the rain will be light to locally moderate. However, Saturday night elevated instability increases and may allow for some heavier showers and thunder. No severe weather is expected. Highs will be cooler than the normals for early April on Saturday. Highs may just break 50 across LI, NYC and northeast NJ, but likely stay in the 40s up in the Lower Hudson Valley and southern CT. Lows Saturday night will actually run a bit warmer than normal, in the 40s. && .LONG TERM /SUNDAY THROUGH FRIDAY/... The period begins with an amplified ridge in the west and a developing eastern CONUS trough as the ridge in SW Atlantic migrates east. A cold front slowly pushes in from the west and moves across on Sunday. This will yield high end chance and lower end likely PoPs for much of the CWA during the day Sunday. PoPs then increase further Sunday night as some strung out PVA is progged just downstream by NWP on a SW flow aloft. This should develop a wave or waves of low pressure along the boundary late Sunday into Sunday night / early Monday. Uncertainty remains slightly above average with respect to how far to the south and east the cold front slows down and possibly stalls late Sunday into early Monday. For now have taken a middle of the road approach and followed consensus PoPs, thus stuck very close to the NBM in this regard. Any low pressure that develops gets east of the area later Monday into Monday night. Thus, any likely PoPs move offshore Monday afternoon into Monday evening. A secondary boundary, a cold / occluded type boundary approaches into Tuesday morning. It won't be until we get behind this boundary that a large portion of the column dries out. Look for strong cold air advection to follow with a W to NW flow as a cP air mass out of Southern Canada builds. This will result in temperatures not getting out of the 40s during the day Tuesday with variable cloudiness with a cold pool aloft and likely strat-cu cloud deck at times. 850 mb temps are progged to get down to -10 to -12C with 1000- 500mb thickness in the lower 520s by Wed AM. Wed AM wind chills are likely to get down into the upper teens to lower 20s across a good portion of the area, with actual air temperatures mainly around or below freezing. With high pressure in control look for dry conditions for the mid week. The high will begin to push offshore sometime on Thursday with a return flow out of the south developing. Temperatures begin to moderate on Thursday, with coastal areas remaining rather chilly with a wind off the ocean during the afternoon hours which will likely drop temperatures back into the 40s. Towards Friday low pressure out of the Ohio Valley and its attendant frontal system will start to draw closer. Any precipitation though will likely hold off until either late in the day or at night based on the latest NWP consensus. && .AVIATION /20Z FRIDAY THROUGH WEDNESDAY/... A cold front will settle over the Mid Atlantic states by early this evening before lifting back to the north late tonight into Saturday. At the same time, high pressure will build in from NW, passing to the north and east tonight. VFR through tonight. Overrunning rain will begin to work into the area Saturday morning, mainly after 12Z. Ceilings and visibilities will gradually lower through the afternoon, with IFR/LIFR conditions expected. NW winds around 10 kt with occasional gusts to 15-20kt will quickly drop off early this evening. Winds will then veer to the N this evening, NE overnight, becoming ESE toward 12Z Saturday, increasing to 10-15kt G20kt. ...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty... No unscheduled amendments expected. Occasional gusts 15-20kt early. .OUTLOOK FOR 18Z SATURDAY THROUGH WEDNESDAY... Saturday Afternoon/Night: Rain and/or drizzle likely with IFR/LIFR conditions. Isolated thunderstorm possible at night. SE winds G15-20kt in the afternoon. Sunday: Becoming MVFR with a chance of showers, then MVFR/IFR in rain Sunday night. Monday: Rain, mainly early, with MVFR conditions, IFR possible. Tuesday: VFR. A slight chance of showers. NW winds 15kt, G25-30kt. Detailed information, including hourly TAF wind component forecasts, can be found at: https:/www.weather.gov/zny/n90 && .MARINE... Sub SCA conditions expected tonight with high pressure passing overhead. An easterly flow picks up on Saturday and conditions may reach marginal SCA criteria on the ocean waters. For now, no headline is in effect. Winds lower again on Saturday night. Mainly sub advisory conditions prevail on the coastal waters, with perhaps the eastern ocean waters being an exception with seas around 5 ft at times Sunday through Monday night. Behind a secondary cold front Tuesday look for small craft conditions to develop on all the waters with a W to NW wind increasing. A brief period of marginal gales is possible late in the day Tuesday into the first half of Tuesday night. Sub advisory conditions return by Wednesday. && .HYDROLOGY... There are no hydrologic concerns through next week. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...JE/JT NEAR TERM...JT SHORT TERM...JT LONG TERM...JE AVIATION...DW MARINE...JE/JT HYDROLOGY...JE/JT