####018007738#### FXUS61 KOKX 161827 AFDOKX Area Forecast Discussion National Weather Service New York NY 227 PM EDT Fri May 16 2025 .SYNOPSIS... Multiple surface troughs move through today and Saturday, followed by a cold frontal passage Saturday night. A secondary cold front moves through Sunday afternoon and Sunday night. Low pressure lingers in New England and into the Canadian Maritimes through Monday as high pressure pushes in. High pressure remains in control Tuesday into Tuesday night. Another frontal system impacts the area Wednesday into Thursday. && .NEAR TERM /THROUGH TONIGHT/... Remnant MCS that had been advancing east through Pennsylvania has weakened substantially as it reached the local region, with only a few lingering showers over western LI at 18Z. Largely dry conditions expected thru the remainder of the day, with an outside chance of a few isolated showers popping up as forcing remains rather weak with a slow moving boundary to the south over the Mid Atlantic, and parent low parent well off to the west. CAMs have been hinting at another MCS developing along the boundary tonight, before working east. Should this occur, it's possible the remnants work into the region toward and after 3Z Sat, though this is far from a guarantee, and any local severe risk from this potential activity is low. Otherwise, likely see areas of fog development once again into the night with light flow and abundant surface moisture. The fog may become locally dense depending on the evolution of any convective system to the west. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... The upper level low continues approaching on Saturday with shortwave energy ejecting out ahead of it. Similar forecast challenges in the morning hours as there may be some sort of approaching convection left over from what happens in the Ohio Valley and Great Lakes region tonight. Then, once again, the area destabilizes ahead of a cold front. While CAMs are not overly excited about this either, there is potential for more widespread convection over the area Sunday afternoon given stronger forcing, instability(MLCAPE approaching 2000 J/kg) and shear(0-6km bulk shear around 40kt). This will also lead to more widespread chances of storms reaching severe thresholds. The SPC has placed the western half of the area in a slight risk. As of right now, the main threat is damaging wind gusts. Model hodographs will have to be watched as there is some indication of favorable low level shear and an isolated tornado can not be ruled out. Latest Nam3km and HRRR show around 150 m2/s2 of effective inflow layer SRH. The cold front moves through Saturday night and then a secondary cold front moves through Sunday and Sunday night. PoPs lower significantly, but there will be additional slight chances of showers across the interior Sunday afternoon with the upper low above us. && .LONG TERM /MONDAY THROUGH FRIDAY/... Mostly sunny skies take over as high pressure centered over or near Hudson Bay in Canada gradually noses into the area Monday into Tuesday night, keeping the area dry. To our northeast, low pressure will continue to exit into New England and into the Canadian Maritimes through. This will lead to breezy W/WNW winds from an increased pressure gradient through Monday. A frontal system from the Great Plains then moves into the Ohio or Tennessee River Valleys on Tuesday, moving through or in the vicinity of our region Wednesday into Thursday. Expecting showers during this timeframe. Too soon to call chances for thunderstorms. Model guidance still varies with timing, magnitude, and track of this frontal system. Have gone with chance POPs Wednesday into Thursday as a result. Temperatures look to cool each day in the long-term period, especially towards Wednesday and Thursday with clouds and rain limiting any heating. Highs on Monday will be in the upper 60s to lower 70s and by Thursday, with will be in the upper 50s to lower 60s. Overnight lows will range from the middle 40s to lower 50s. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... Weak low pressure with a surface trough near the area today, followed by a warm front moving through Saturday. Cold front follows for Saturday evening. Showers and embedded thunderstorms moving farther southeast away from the local area. Mainly dry conditions expected through early this evening. Two additional rounds of precipitation in the TAF period. Next one is coming up late this evening into overnight, just mainly showers north and west of NYC. Next one after that is Saturday afternoon into early Saturday evening which is when showers and thunderstorms will be possible. Conditions initially this afternoon have improved to mainly VFR with some lingering isolated MVFR and below. Tonight, IFR to LIFR with the redevelopment of low clouds and fog. These low conditions will linger into Saturday morning. Some improvement is expected to close out the TAF period. Southerly flow near 5-10 kts expected through much of the TAF period. Southerly winds pick up to near 10-15 kt with some gusts up to 20 kt Saturday afternoon. ...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty... Timing of IFR, MVFR, and LIFR changes could be a few hours off from TAF. VLIFR possible early Saturday, 08-12Z. .OUTLOOK FOR 18Z SATURDAY THROUGH WEDNESDAY... Saturday: Mainly VFR but MVFR possible in the afternoon with chance of showers, and a slight chance of thunderstorms with MVFR conditions. Sunday: Mainly VFR. Slight chance of showers inland with MVFR possible. W winds G20-25kt. Monday - Tuesday: VFR. Monday NW winds G20-25kt day into evening. Wednesday: MVFR or lower with showers likely, mainly at night. E wind gusts 15-20 kt. Detailed information, including hourly TAF wind component forecasts, can be found at: https:/www.weather.gov/zny/n90 && .MARINE... Areas of fog return tonight, potentially becoming dense again and persisting into mid Saturday morning. Winds and waves remain below SCA criteria through Sunday for the most part. There looks to be brief potential for 25 kt gusts Sunday afternoon, mainly for NY Harbor, western Sound and western Ocean. During this time, seas on the ocean could also approach 5 ft. Outside of this, there is potential for showers and thunderstorms each day, with potential for severe thunderstorms Saturday afternoon. Winds and seas will be locally higher in any storms. Winds are expected to remain below SCA criteria for Monday. However, there is a low to medium chance of 25 kt wind gusts over the ocean waters with low pressure over the Gulf of Maine creating an increased pressure gradient. Thereafter winds and waves should remain below SCA criteria due to lack of any strong pressure gradient across the waters. && .HYDROLOGY... Locally heavy downpours are possible with any thunderstorms this afternoon, and again Saturday aft/eve. While the overall flash flood threat is low, the brief heavy rainfall could lead to minor nuisance flooding in urban and poor drainage areas. There are no other hydrologic concerns through the end of next week. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...JP/JT NEAR TERM...DR/JT SHORT TERM...JT LONG TERM...JP AVIATION...JM MARINE...DR/JP/JT HYDROLOGY...DR/JP/JT