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FXUS61 KOKX 212025
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
425 PM EDT Thu Mar 21 2024

.SYNOPSIS...
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High pressure builds in from the south and west through Friday. Low pressure approaches from the south Friday night into Saturday and moves across late Saturday afternoon into early Saturday evening. This low pressure system then moves east of the region for the remainder of Saturday night. High pressure ridges down from the north Sunday into Monday and remains into Tuesday. A frontal system approaches from the west Tuesday night and moves slowly eastward through midweek.
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&& .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
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High pressure builds in from the south and west through tonight. Mostly clear sky conditions are expected but winds will gradually lower as a result of a weakening pressure gradient. Radiational cooling will be effective but not totally maximized with winds staying up within the boundary layer. Forecast lows are in the upper teens to upper 20s.
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&& .SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY/...
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Dry conditions are expected to continue with high pressure in control Friday. Winds will be light and daytime mixing will be limited. With increasing clouds in the afternoon, daytime high temperatures are only forecast to be in the low to mid 40s which will be below normal for this time of year. Low pressure and an upper level trough approach Friday night. For Friday night, cloud coverage will eventually become overcast with rain showers starting overnight and into daybreak Saturday. Low pressure continues to approach the region Saturday with an increase in SE flow. The trough will continue to approach as well aloft with an associated increase in precipitable water. This will lead to a greater moisture potential with this approaching system. Rain becomes steady, falling at moderate to occasionally heavy intensities during the day. There is a flood watch in effect for NE NJ, NYC, Rockland NY, Westchester NY for 4AM Saturday through 2AM Sunday. Less of a diurnal temperature range expected Friday night into Saturday. Used consensus of raw model data Friday night and Saturday. Forecast actually has increasing temperatures late Friday night into Saturday morning. Depending on exact start time, there could be a brief mix of rain and snow for some parts of the far interior but expect any accumulations of snow to stay under an inch. This will be primarily a rain event.
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&& .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
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With the precipitation ending during Saturday night, leaned more toward the global guidance which is a little quicker than the NBM. Upper troughing, and the surface low will be moving into the western Atlantic through Sunday night, and then track slowly east into early next week. Meanwhile an upper ridge builds into the eastern coast Monday and moves offshore Tuesday, as surface high pressure noses into the coastal plain from the north. With high amplitude riding moving through the western Atlantic an approaching low pressure system Tuesday,moves slowly across Tuesday night into Thursday. *Key Messages* * Lingering rain into Saturday night, then dry Sunday through Tuesday. * Gusty northerly winds likely late Saturday night through Sunday. Remaining gusty, especially east, Sunday night into Monday evening. * Unsettled, wet weather returns Tuesday night into Thursday. * Near normal temperatures expected Saturday night through Wednesday with a slight warm up Wednesday night and Thursday.
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&& .AVIATION /20Z THURSDAY THROUGH TUESDAY/...
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High pressure through Friday. VFR. NW winds and gusts 15-25kt with G30kt early this evening will be diminishing after 00Z Friday. Winds becoming W around 10 kt Friday. NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty... No unscheduled amendments expected. OUTLOOK FOR 18Z FRIDAY THROUGH TUESDAY... 18z Friday: VFR. Friday night: MVFR or lower developing after midnight with rain near the coast and rain perhaps some brief wet snow inland for KSWF. Saturday: IFR and rain. Rain heavy at times into evening. SE wind gusts 20-25kt during the day with LLWS possible city east, becoming N all areas with gusts 30-35kt at night. Sunday: VFR. A slight chance of rain. N-NE wind gusts around 25kt. Monday: VFR. NE gusts 20-25kt. Tuesday: VFR. Detailed information, including hourly TAF wind component forecasts, can be found at: https:/www.weather.gov/zny/n90
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&& .MARINE...
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The pressure gradient remains tight between low pressure going into the Canadian Maritimes and high pressure to the north and west of the local waters. Gusty NW flow remains through this afternoon and into much of this evening before more substantially diminishing overnight. SCA for all forecast waters continues until 11PM. Then, with some lingering gusts and higher seas over the eastern parts of the forecast ocean waters, SCA from Fire Island to Montauk continue until 6AM Friday. After 11PM aside from these eastern ocean zones, sub-SCA conditions are expected. A relaxing pressure gradient due to high pressure building in will allow for conditions to go below SCA criteria for most waters late tonight and then for all waters Friday into Friday night. Conditions on Saturday trend back up to SCA range for wind gusts for most waters and seas on the ocean. Western LI Sound and NY Harbor are below SCA criteria Saturday in current forecast but may trend more into SCA with wind gusts on subsequent forecasts. Strong and gusty northerly winds will develop behind a departing low pressure system Saturday night. Winds and gusts will be increasing to SCA levels across all the waters, with gale gusts becoming likely across all the waters by late Saturday night. Gales on the non ocean waters will be ending Sunday morning, with SCA conditions then continuing into Monday night. Meanwhile, gales will be remaining on the western ocean waters into late day Sunday, and the eastern waters into Monday night as offshore low pressure remains nearby and slowly weakens. Once gale conditions end on the western ocean SCA conditions will then remain into Monday night.
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&& .FIRE WEATHER... Based on collaboration with Fire WX partners and surrounding WFOs, there are special weather statements for the entire region with elevated fire weather concerns today into early this evening. Gusty winds around 25 to 30 mph are expected with Min RH values of 25 to 30 percent. The airmass remains anomalously dry as rainfall the last 24 hours was mostly under a tenth of an inch, therefore not sufficiently wetting the ground. && .HYDROLOGY...
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Dry until late Friday night into early Saturday morning when rain begins entering the area. Rain steady, moderate to heavy during the day Saturday. Rain tapers off Saturday night from west to east. Total rainfall forecast near 2 to 3 inches withe locally higher amounts possible. There will be potential for flooding for NE NJ, NYC, as well as Rockland and Westchester counties in NY. This region contains rivers and streams that may potentially flood especially if locally higher than 3 inch rainfall amounts occur. Low lying, poor drainage and urban areas will also be vulnerable spots prone to flooding. There is a flood watch in effect from 4AM Saturday until 2AM Sunday for these aforementioned areas. Hydrologic issues prior to Saturday night, rain ending during Saturday night with little west, couple of hundredths, to 1 to 1.25 inches east. No hydrologic issues expected Sunday through the middle of next week.
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&& .OKX WATCHES/WARNINGS/ADVISORIES...
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CT...None. NY...Flood Watch from late Friday night through late Saturday night for NYZ069>075-176-178. NJ...Flood Watch from late Friday night through late Saturday night for NJZ002-004-006-103>108. MARINE...Small Craft Advisory until 11 PM EDT this evening for ANZ331- 332-335-338-340-345-355. Small Craft Advisory until 6 AM EDT Friday for ANZ350-353.
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&& $$ SYNOPSIS...JM/MET NEAR TERM...JM SHORT TERM...JM LONG TERM...MET AVIATION...IRD MARINE...JM/MET FIRE WEATHER... HYDROLOGY...JM/MET