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FXUS61 KOKX 112142
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
442 PM EST Thu Jan 11 2024

.SYNOPSIS...
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An area of low pressure dissipates across western New York tonight, while high pressure builds in from the west. Another strong low pressure system low will track to our west and impact the area Friday night into Saturday. The low will send a cold front through the area early Saturday, followed by a secondary cold front on Sunday. High pressure briefly builds in for the end of the weekend into early next week. A coastal low looks to potentially impact the area sometime early to mid next week. High pressure briefly builds in thereafter.
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&& .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
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A weak area of low pressure is association with a passing mid level shortwave trough will dissipate across western New York state this evening. It`s possible for a sprinkle and/or flurry across western portions of Orange County this evening, otherwise we can expect mostly clear skies with high pressure building in from the west. W/SW winds will gradually diminish and become NW by morning. Lows will be in the upper 20s/lower 30s for all but the NYC metro, where it will be a few degrees warmer.
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&& .SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY/...
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Another strong, negatively tilted upper trough will lift northeast across the mid Mississippi Valley on Friday and up into the Great Lakes Friday night, preceded by deepening low pressure. A strong frontal system out ahead of the low will be preceded by deep-layered lift and anomalously high PWATs (1.15-1.30"). Friday will be mainly dry as high pressure passes to the east. NW winds in the morning turn around to the SE by afternoon. Rain will advance across the area from SW to NE during the late evening, overspreading the entire area by around or shortly after midnight. This will be a progressive system with the heaviest rain clearing far eastern LI and SE CT by around 8 AM. This system will bring less rainfall to the area than it`s predecessor, a widespread 1 to 2 inches, with locally higher amounts possible. However, due to the recent stretch of rainfall events, starting back in mid December, streamflows are running high, and grounds are saturated. FFG values are extremely low across NE NJ (under an inch), and while higher elsewhere, it will not take long for faster responding river and streams to reach or exceed bankfull. In addition, a strong SE flow will favor orographic enhancement. Thus, a Flood Watch has been issued for Friday night for NE NJ, portions of the Lower Hudson Valley (Rockland and Westchester), and all of southern CT. Coastal flooding could also exacerbate flooding for tidal rivers. Elsewhere, the threat will be for mainly minor nuisance freshwater flooding (outside of coastal flooding - see sections below), but basement flooding has also been a problem for the area due to the saturated soils. SE winds will steadily ramp up during the evening hours Friday with the potential for winds reaching advisory levels across coastal sections after midnight, especially Long Island. Expect gusts up to 40 mph inland and 45 to 55 mph at the coast. A few lingering showers are possible Saturday morning, otherwise conditions dry out with clearing. Gusty west winds on the backside of the storm system will get up to 35 mph. Cold advection will also ensue following a cold frontal passage in the morning. Temperatures Friday through Saturday will remain on the warm side. In fact, temperatures ahead of the cold front Saturday morning will get to around 50 at the coast. Thereafter, readings may remain steady before falling off late in the day.
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&& .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
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As strong surface low pressure, and associated upper level low, continue to move into eastern Canada Saturday night, the area remains in a tight pressure gradient as high pressure starts to build in. Windy conditions will continue, with 25 to 30 mph gusting 35 to 40 mph through Sunday, with a few isolated higher gusts possible along the coast. Later on Sunday, a shortwave trough rotating around the upper low will move over the area and help push a cold front through. This will usher in the coldest airmass of the season for the area. A few light snow showers will be possible with the front. Extended slight chance a bit further into the Lower Hudson Valley, but did not go farther east as confidence is still low. This may trend up over the next several forecasts. High pressure continues to build in from the west and the pressure gradient looks to finally relax by early Monday. High pressure will only briefly be in control as attention then turns to a potential coastal low that looks to impact the area sometime early to mid next week. Uncertainty remains with this system, and model spread has actually increased with today`s 12z guidance vs the 00z guidance. Although slight timing differences, the GFS and Canadian are similar and closest to the coast with the low. However, their ensembles are farther south and east. The latest ECMWF is a big change from the previous run and shows a much weaker low well offshore, leaving the area dry. This is the result of a less amplified upper level trough and any energy out ahead of the trough staying farther south off the southeast coast. Stuck relatively close to NBM given the spread across guidance. PoPs are capped at low end likely for the southern half of the area. Given the cold air in place, taking a mean track between the ensembles and deterministic guidance, excluding the ECMWF, precip type looks to be snow across much of the area, with rain and/or snow across Long Island. Did no want to jump on the ECMWF outlier yet, but this trend will have to be monitored. At this time it is too early to talk specific amounts. Behind this system, brief high pressure looks to build in. Temperatures will trend down From Sunday through the middle of next week. Highs in the mid to upper 20s are forecast Wednesday.
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&& .AVIATION /21Z THURSDAY THROUGH TUESDAY/...
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Weak high pressure will remain over the area through tonight before moving offshore on Friday. An area of low pressure then approaches from the southwest Friday afternoon. VFR through the TAF period. W winds will diminish into the evening. A few lingering gusts to around 20 kt are possible through 22Z. Winds then shift to the NW at less than 10 kt tonight before becoming light and variable early Friday morning. ...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty... No unscheduled amendments expected. OUTLOOK FOR 18Z FRIDAY THROUGH TUESDAY... Friday: VFR. Friday night: Becoming MVFR early, then IFR or lower in rain. SE winds 15-25kt G30-40kt. Winds and gusts highest along the coast. Saturday: MVFR or lower early in rain, then VFR. S winds becoming W 20-30kt G30-35kt. Sunday...VFR. W 15-25kt G30-35kt. Monday...Mainly VFR. Low chance for light snow late with MVFR to IFR. Tuesday...MVFR or lower possible with a chance of snow or a rain/snow mix. 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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Storm and Gale watches remain up for Friday night as another strong low passes to the west, resulting in strong SE winds. Behind the system, a westerly gale is likely on Saturday, especially for the ocean waters. Although the center of the low will be well to our north Saturday night, windy conditions will continue across the waters. Gale conditions are expected on all waters through at least Sunday and lingering on the ocean waters through the first half of Sunday night. Small craft conditions likely only last a few hours longer on the non-ocean waters, but will continue on the ocean with 5 ft waves through early Monday. Quiet conditions then expected until a coastal low potentially impacts the area sometime early to mid next week. At this time, at least Small Craft Advisory criteria is expected.
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&& .HYDROLOGY...
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Some river flood warnings continue across portions of NE NJ and southern CT. The Passaic River is still in moderate to major and will crest later tonight, otherwise other locations are receding from minor levels. Hydrologic impacts are likely Friday night into Saturday. WPC continues a slight risk of excessive rainfall, due to another round of moderate to heavy rain. One to two inches of rainfall is currently forecast, with locally higher amounts possible. With rivers and streams running high from previous rainfall, widespread minor to moderate river flooding looks likely along the quick responding rivers and streams in Northeast NJ, the Lower Hudson Valley and southern CT. There are no hydrologic concerns Saturday night through Thursday at this time. It is too early to talk specific amounts with the potential coastal low sometime early to mid next week, but in areas with recent hydrologic issues, precip type is expected to be mainly in the form of snow at this time.
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&& .TIDES/COASTAL FLOODING... Widespread moderate to locally major coastal flood impact potential for the Saturday morning high tide as SE gales build surge to 3-4 ft Fri night, with a wind shift to SW gales Saturday morning near the time of high tide. Timing of wind shift will be critical for magnitude of surge. This scenario, like the Tue night and and Dec 18th events, is conducive to water piling up in the Great South Bay during strongest wind forcing, inhibited from drainage thru inlets as tide comes in and accompanied by high wave action, and then shifting this elevated water to the east side of the bay with the wind shift. Elsewhere, widespread minor to locally moderate flooding is likely. Along the oceanfront, breaking surf height should be lower than the last couple of events, but 12-16 ft breaking surf with similarly elevated water levels impacting compromised dune structure will likely result in another round of widespread dune erosion and scattered overwashes. Localized breaches possible where dunes have been severely compromised and barrier beaches are narrow. Forecast details will be refined over the next 48 hrs. && .OKX WATCHES/WARNINGS/ADVISORIES...
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CT...Flood Watch from Friday evening through Saturday morning for CTZ005>012. Coastal Flood Advisory from 9 AM to 3 PM EST Saturday for CTZ009-010. Coastal Flood Warning from 7 AM to 2 PM EST Saturday for CTZ011-012. NY...Flood Watch from Friday evening through Saturday morning for NYZ069>071. Coastal Flood Advisory from 9 AM to 3 PM EST Saturday for NYZ071-073-078-176-177. Coastal Flood Warning from 7 AM to 2 PM EST Saturday for NYZ178. Coastal Flood Advisory from 7 AM to 2 PM EST Saturday for NYZ072-074-075. Coastal Flood Warning from 7 AM to 6 PM EST Saturday for NYZ079>081-179. NJ...Flood Watch from Friday evening through Saturday morning for NJZ002-004-006-103>108. Coastal Flood Advisory from 7 AM to 2 PM EST Saturday for NJZ006-104-106-108. MARINE...Gale Watch from Friday evening through Saturday afternoon for ANZ331-332-335-338-340-345. Small Craft Advisory until 10 AM EST Friday for ANZ350-353. Storm Watch from Friday evening through late Friday night for ANZ350-353-355. Small Craft Advisory until 6 AM EST Friday for ANZ355.
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&& $$ SYNOPSIS...JT/DW NEAR TERM...DW SHORT TERM...DW LONG TERM...JT AVIATION...FEB MARINE...JT/DW HYDROLOGY...JT/DW TIDES/COASTAL FLOODING...