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FXUS61 KOKX 252025
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
325 PM EST Sat Nov 25 2023

.SYNOPSIS...
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High pressure over the region tonight will slowly move off the New England coast on Sunday. Low pressure then impacts the area Sunday night into early Monday morning. High pressure slowly builds in Monday afternoon through Wednesday followed by low pressure passing to the north of the area Wednesday night. High pressure then returns for late in the week followed by low pressure approaching from the southwest late Friday.
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&& .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
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Dry and cold conditions will continue tonight with high pressure over the region. The main challenge will be with temperatures and the amount of cloud cover. The first half of the night will likely be mostly clear. However, mid and high clouds increase well ahead of an amplifying upper trough over the Plains. Temperatures will fall quickly this evening under mostly clear skies and light winds before leveling off or only slowly falling early Monday morning. Lows look to be similar to Friday night/early Saturday for most locations with readings in the lower 20s inland and middle and upper 20s elsewhere. Since cold advection has ended, NYC likely stays just above freezing. If clouds are quicker to move in overnight, lows may end up a few degrees warmer. If the clouds are slower to move in, then lows could be a few degrees colder outside of the NYC metro.
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&& .SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY/...
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High pressure slowly shifts offshore on Sunday as heights aloft gradually fall in response to the aforementioned amplifying upper trough. The return flow around the surface high will help bring an increase in moisture in the low levels through the day. Moisture profiles indicate saturation occurring around 3-5 ft which will result in a stratocu deck expanding from south to north through the day. An inverted trough off the Carolinas will also develop a low pressure late in the day. Have continued to keep the forecast dry for the daytime hours on Sunday. Temperatures will moderate into the 40s for highs, a few degrees below normal for this time of year. The upper trough will interact with the developing low near the North Carolina coast Sunday evening. The trough will help lift this low towards the area overnight. The model guidance is in fairly good agreement that the low will near the Long Island coast after 06z and then track towards Cape Cod by 12z Monday. This fast movement is supported by the progressive synoptic pattern in place. The system will bring a quick shot of rain beginning late Sunday evening and continuing into early Monday morning. The rain could become moderate at times, especially across Long Island and southern Connecticut, where slightly stronger thermal forcing sets up closer to the low center. The rain will end quickly from west to east from early Monday morning as the low pulls away to the northeast. Confidence is fairly high that the rain will end by the beginning of the morning rush hour from the NYC metro on north and west. The rain should end by around 12z across eastern Long Island and southeast Connecticut. Forecast amounts range from around a half inch or less along the Hudson River corridor to three quarters to an inch eastern Long Island and southeast Connecticut. While winds may briefly become gusty for eastern portions of the area late Sunday night, stronger winds are more likely on Monday behind the low. The pressure gradient tightens on Monday due to the low continuing to deepen as it tracks into SE Canada by late day. This will bring increasing winds into Monday afternoon with sustained winds 15-20 mph gusting 25-30 mph. A few gusts up to 35 mph are possible near the coast in the afternoon. Temperatures may peak in the upper 40s to low 50s early in the day and then fall in the afternoon as colder air begins advecting into the area.
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&& .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
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Global ensemble guidance is in agreement with the overall pattern evolution with an anomalously deep low centered over eastern Canada to start the period with a more zonal pattern taking shape by week`s end. The NBM with some adjustments to winds/gusts was predominately used for this forecast update. The highlights for the long term are: * Below normal temperatures for much of the period with Tuesday and Wednesday the coldest days. A gradual warmup ensues thereafter, into next weekend. * Dry and windy conditions Monday night through Wednesday, with the next chance of precipitation late Friday into Saturday. A strong pressure gradient remains intact as a surface low continues to deepen as it heads northeast of the region on Tuesday. Behind this system, cold air advection and thicknesses in the low 500s dam will result in a blustery, but dry, period. NBM winds have been adjusted up toward the 90th percentile from Monday night into Tuesday afternoon, as model soundings indicate deep mixing up to 650- 700mb. In addition, an upward trend in NBM winds/gusts was noted over the past several cycles with 30-35mph gusts looking more and more likely late Monday and again on Tuesday afternoon. Given the combination of cold temperatures (low to mid 20s) and elevated winds, wind chills in the upper teens and lower 20s are possible Monday night and Tuesday night, should the forecast hold. Highs on Tuesday and Wednesday will struggle to get into the 40s for the urban and coastal areas, and into the upper 30s across the interior. The upper flow deamplifies by late Wednesday into Thursday with a return to southerly flow as sfc high pressure slides offshore. This will allow temperatures to moderate a bit, Thursday and Friday, into the mid and upper 40s, as dry conditions continue. By late Friday, guidance is advertising a low pressure approaching the area from the southwest, as a southern stream mid/upper shortwave lifts out of the Southern Plains. For now, given the large uncertainty this far out, have maintained the NBM chance PoPs starting late Friday.
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&& .AVIATION /21Z SATURDAY THROUGH THURSDAY/...
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High pressure builds overhead into this evening, moving offshore late tonight. VFR. Winds remain light, less than 10 kt, through tonight. Direction backs to the W, then S/SW late today, before becoming light and variable at all terminals this evening. S/SE flow on Sunday with speeds under 10 kt. Lowering cigs late Sun AM into the afternoon ahead of the next incoming storm system that brings rain to the terminals Sunday evening. MVFR cigs develop by the afternoon or early evening. ...NY Metro(KEWR/KLGA/KJFK/KTEB) TAF Uncertainty... No unscheduled amendments expected. Timing of wind direction changes may be off by a few hours. Timing of MVFR cigs on Sunday may be off by a few hours. OUTLOOK FOR 21Z SUNDAY THROUGH THURSDAY... Sun PM: Rain showers develop in the evening, with MVFR or lower conds. Mon: Improvement to VFR in the morning. WNW wind 15-20kt, G25-30kt. Tue: VFR. W wind 15-20kt, G25-35kt. Wed: VFR. SW wind 10-15kt, G20kt. Thu: VFR. W wind 10-15kt, G20kt. 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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Tranquil conditions will persist on the waters through Sunday as a weak pressure gradient remains in place. Low pressure then develops along the Carolina coast late Sunday and quickly tracks over the waters Sunday night into early Monday. This will bring an increase in winds with the best chance for SCA conditions on the ocean east of Moriches Inlet. Seas may also build to around 5 ft east of Moriches Inlet late Sunday night. Have held off on the issuance of an SCA for now. SCA conditions are more likely on all waters on Monday as the low pulls away to the northeast. Latest trends in the model guidance indicate lower potential for gales on Monday, but will still mention in the HWO for now on the ocean. The increasing winds will result in 6 to 8 ft waves on the ocean waters and 4 to 5 ft waves across the central and eastern Sound. SCA conditions continue Monday night into Tuesday evening on all waters. There is a chance of a short period of gales on the ocean waters Tuesday afternoon. Conditions will be improving slowly from the west as high pressure builds into the area by Wednesday morning. SCA conditions will remain on the ocean waters, mainly east of Fire Island Inlet. Marginal SCA conditions then remain on the ocean waters Wednesday night into Thursday as the pressure gradient remains rather strong as a low passes to the north.
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&& .HYDROLOGY...
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Dry conditions will continue through Sunday afternoon. There are no hydrologic concerns from around one half to one inch of rain Sunday night into early monday morning. There are no hydrologic concerns Monday afternoon through Friday.
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&& .TIDES/COASTAL FLOODING...
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Astronomical tides will be increasing into early next week due to a full moon early Monday morning. Water levels may just touch minor benchmarks during the Sunday morning high tide for a few vulnerable locations across the south shore back bays of Nassau and along coastal Fairfield. Have held off on any statements at this time. Minor coastal flooding looks more likely for the south shore back bays of Nassau and Queens, Western Long Island Sound across coastal Westchester and coastal Fairfield with the Monday morning high tide. A quickly developing low pressure may help bring enough of a surge (only around 0.50-0.75 ft needed) to reach minor benchmarks. Water levels may also come close to minor benchmarks across the Lower NY Harbor and the bays along the SE coast of Long Island.
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&& .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...DBR/DS NEAR TERM...DS SHORT TERM...DS LONG TERM...DBR AVIATION...DR MARINE...DBR/DS HYDROLOGY...DBR/DS TIDES/COASTAL FLOODING...JT/DS