000
FXUS61 KOKX 030035
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
835 PM EDT Tue Apr 2 2024

.SYNOPSIS...
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A warm front will continue to slowly approach from the south tonight. Low pressure strengthening to the southwest early Wednesday will then pass over or just south of the area Wednesday evening through Thursday morning. The low will drift slowly east of New England later this week into Saturday, with high pressure building in early next week.
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&& .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
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A warm front will continue to slowly approach from the south tonight as strong surface low pressure and an upper low slowly spin in place near the western Great Lakes. Latest radar trend and hi-res guidance indicate light rain lessening in coverage from west to east this evening before picking up again after midnight. E flow will continue and strengthen overnight. Gusts along the coast should likely reach 30 to 35 mph. Temperatures won`t drop too much overnight with the strong easterly flow, rain and cloud cover. Expect lows in the upper 30s/lower 40s.
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&& .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY/...
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Upper level low and associated surface low continue to spin in place over the Great Lakes Wednesday through Wednesday night. Low pressure then forms along a frontal boundary near the Mid- Atlantic extending southeast of the low over the Great Lakes. This low looks to strengthen and pass over or just south of our area deepening to around 985mb. This low will bring another round of moderate to locally heavy rain as well as high winds. Model fcst winds have increased over the past few runs and have bumped forecast winds up. Both the 12z NAM and GFS show 65 to 75 kt at 925mb. Bufkit soundings show no real inversion in place with mean boundary layer winds around 50 kt at several coastal locations. Have issued a High Wind Watch for all of Long Island, NYC, coastal CT and southern Westchester and Hudson Counties. In these areas, expecting a period from mainly Wednesday afternoon through the first half of Wednesday night where wind gusts could potentially reach 60 mph. Elsewhere (except Orange County and Western Passaic County) have issued a Wind Advisory for 45 to 50 mph wind gusts. As previously mentioned, this low will also bring another round of moderate to locally heavy rain to the area, as well as the potential for isolated thunderstorms. See hydrology section below. Any thunderstorms are expected to remain below severe criteria as instability is real marginal. MUCAPE values will likely only be up to a few hundred J/kg. The Storm Prediction Center has maintained the "general thunderstorm" area in their outlook. This low will also bring coastal flooding to the area. See the tides/coastal flood section below. As the low pull away, cold air gets wrapped up into the system and precip may end as a wintry mix across far northern and western locations. At this time, there is potential for snow and sleet to mix in. There will likely be little to no accumulation due to marginal surface temperatures.
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&& .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
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A blocky pattern will persist through the period courtesy of a developing omega block over the CONUS and southern/central Canada. Its eastern leg (the upper low associated with this week`s storm) will be moving across Thu night, accompanied by snow/rain showers especially in the evening. Another fairly good chance for showers will come on Friday as a mid level vort max trailing the upper low moves across. This disturbance will have some low level instability to work with as model fcst sounding show steep sfc-H7 lapse rates and available moisture above the LCL, so have bumped up NBM PoP to at least 30 percent throughout, and while fcst does not include this could not entirely rule out some isolated thunder and/or graupel/small hail with some of this activity. Another vort max pinwheeling around the slow moving upper low E of New England should bring another chance for showers on Sat mainly across S CT and ern Long Island. Then fair and milder wx likely for Sun-Tue with sfc high pressure finally building in and heights rising aloft. Siding more with slower ECMWF vs faster GFS solution with a weakening upper ridge axis sliding across, and some mid level shortwave energy riding atop the ridge axis in the afternoon. This means there could be a fair amt of bkn high clouds present during the time of the solar eclipse in the afternoon. Temps a few degrees below normal Thu night through Sat should moderate to near normal on Sunday, then warm up to a few degrees above normal Mon-Tue, with highs in the lower/mid 60s both days.
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&& .AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
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A large developing low pressure system will impact the area through Thursday. The center of the low passes over the area Wednesday night into Thursday morning. Mainly IFR expected for all terminals through the TAF period. LIFR conditions will be possible, especially for coastal terminals. Widespread rain becomes lighter this evening and overnight. More steady and moderate rainfall moves into the area during the day Wednesday. Heavy rain with embedded TS possible after 21Z Wednesday, but confidence in occurrence and coverage too low to include in the TAFs at this time. E winds will increase tonight, strengthening significantly on Wednesday. Winds gust beyond 35 kt at the NYC terminals between 12- 15Z. Peak gusts to around 50 kt possible after 18Z Wednesday across the NYC and coastal terminals, particularly at KJFK, KLGA, KHPN, KBDR, KISP. Winds less further inland but gusts up to 40kt remain possible. Winds slowly weaken and become more northerly with the passage of the low pressure after 04Z Thursday. Though winds at 1-2kft will be 50-60 kt Wednesday afternoon into the evening, LLWS was not included in the TAF as surface winds will be strong as well. ...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty... Amendments likely through the TAF period for changing cigs/vis and possible fluctuations in flight categories. Gusts may fluctuate between occasional and frequent tonight before becoming prevailing by 09Z-12Z Wednesday. OUTLOOK FOR 00Z THURSDAY THROUGH SUNDAY... Wednesday Night: IFR or lower in rain. The rain could be mixed with wet snow at KSWF late Wednesday night. E winds with peak gusts around 50 kt possible. Winds 50kt or more at 2kft. Thursday: MVFR or lower with lingering rain, possibly mixed with wet snow at KSWF. NW gusts 20-25 kt. Friday: Mainly VFR. Slight chance of showers. NW flow with gusts around 25kt. Saturday: MVFR possible with N flow. Sunday: VFR with N flow. 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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Winds will be increasing tonight and a Gale Warning is in effect for the ocean W of Moriches Inlet, where gusts up to 35 kt are expected after midnight, with ocean seas building to 7-9 ft. A Storm Warning is then in effect starting Wednesday morning on all waters. Strong low pressure will pass over or just south of the waters and bring a period of 50 kt wind gusts, mainly from Wednesday afternoon through he first half of Wednesday night. Waves on the ocean waters likely reach 15 to 17 ft on the ocean waters and 9 to 11 ft across the Sound. Winds drop below Gale criteria by Thursday morning, with lingering SCA criteria mainly in the form of elevated ocean seas persisting into Thu night-Fri night. Some gusts up to 25 kt are also possible in NW flow Fri afternoon and early evening on most waters, and later into Fri night on the ocean.
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&& .HYDROLOGY...
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An additional 1.5 to 2.5 inches of rainfall is expected tonight through early Thursday. The bulk of this rain will fall Wednesday afternoon and evening. Rainfall rates with the round on Wednesday will be mainly 0.25 to 0.5 inch per hour, with locally 0.75 to 1.0 inches per hour in any thunderstorms. Poor drainage flooding and urban low lying flooding is possible along with minor river flooding across quick responding rivers. The WPC has maintained a marginal risk of excessive rainfall.
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&& .TIDES/COASTAL FLOODING...
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Local minor flooding benchmarks may be reached, or just touched, late tonight/early Wednesday morning along the Long Island south shore back bays. Around 2.5-3 ft of surge is needed for minor coastal flood Wed aft/eve and around 3.5-4 ft for moderate coastal flooding. With easterly winds ramping up through gale to storm force during the time of high tide, as well as building wave action, widespread moderate coastal flood thresholds are likely to be eclipsed along the southern and eastern bays of Long Island and along the western Sound. Elsewhere widespread minor coastal flooding likely. In addition, the combination of heavy rain and elevated water levels on Wednesday afternoon into evening may cause localized flash flooding along some shoreline roads and properties. Easterly winds gradually subside late Wed night as low pressure moves over the area, and then switch to NW gales behind the low Thu AM. High easterly swells will likely inhibit drainage, particularly bay areas, bringing potential for widespread moderate flooding (locally major for the southern and eastern bays of Long Island) late Wednesday night into early Thu morning. The coverage and areas of greatest coastal flood impact will be highly dependent on track of the low, and timing of the wind shift from easterly SCA/Gales to northwest gales. Forecast is based on a 75th percentile of Stevens, blended with ETSS, STOFS guidance, which applies a bit of margin for safety. This will be refined over the next 24 hours. Along the oceanfront, breaking waves of 6-10 ft Wednesday into Thursday morning, along with elevated water levels, will result in widespread beach flooding and erosion. Scattered areas of dune erosion with localized overwashes are likely during the times of high tide Wed afternoon into Thursday morning. Along Long Island Sound, breaking waves of 3-7 ft Wednesday evening, along with elevated water levels, will result in beach erosion with damage to shoreline structures possible. Wave splashover over bulkheads and seawalls will likely exacerbate flooding of shoreline roadways and properties. A similar threat exists for the twin forks, with breaking waves of 4-8 ft Wednesday evening and Thursday morning.
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&& .OKX WATCHES/WARNINGS/ADVISORIES...
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CT...Wind Advisory from 11 AM Wednesday to 5 AM EDT Thursday for CTZ005>008. High Wind Watch from Wednesday morning through late Wednesday night for CTZ009>012. Coastal Flood Warning from 4 PM Wednesday to 10 AM EDT Thursday for CTZ009-010. Coastal Flood Watch from late Wednesday night through Thursday morning for CTZ011-012. NY...Wind Advisory from 11 AM Wednesday to 5 AM EDT Thursday for NYZ068>070. High Wind Watch from Wednesday morning through late Wednesday night for NYZ071>075-078>081-176>179. Coastal Flood Warning from 4 PM Wednesday to 10 AM EDT Thursday for NYZ071-073-078-176-177. Coastal Flood Advisory from 2 PM Wednesday to 7 AM EDT Thursday for NYZ072-074-075. Coastal Flood Warning from 2 PM Wednesday to noon EDT Thursday for NYZ079>081-179. Coastal Flood Advisory from 2 PM to 7 PM EDT Wednesday for NYZ178. Coastal Flood Warning from 3 AM to 7 AM EDT Thursday for NYZ178. NJ...Wind Advisory from 11 AM Wednesday to 5 AM EDT Thursday for NJZ004-103>108. High Wind Watch from Wednesday morning through late Wednesday night for NJZ006. Coastal Flood Advisory from 2 PM Wednesday to 7 AM EDT Thursday for NJZ006-104-106-108. MARINE...Small Craft Advisory until 6 AM EDT Wednesday for ANZ331-332- 335-338-340-345-350. Storm Warning from 6 AM Wednesday to 2 AM EDT Thursday for ANZ331-332-335-338-340-345-350-353-355. Gale Warning until 6 AM EDT Wednesday for ANZ353-355.
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&& $$ SYNOPSIS...BG/JT NEAR TERM...BG/JT SHORT TERM...JT LONG TERM...BG AVIATION...MW MARINE...BG/JT HYDROLOGY...BG/JT TIDES/COASTAL FLOODING...NV