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FXUS61 KOKX 090301
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
1001 PM EST Mon Jan 8 2024

.SYNOPSIS...
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High pressure over the area overnight will move offshore Tuesday morning. Intensifying low pressure will track from the Central States to the Great Lakes Tuesday into Tuesday night. This will send a strong frontal system across the area Tuesday night into Wednesday. High pressure briefly builds in Wednesday night through Thursday night. Another strong low pressure system could bring heavy rain and high winds to the area late Friday through Saturday. Weak high pressure returns Sunday into Monday.
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&& .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
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The brief period of tranquil weather continues overnight. High pressure over the area has lead to mostly clear skies, with calm to very light winds now in place. The leading edge of some high clouds is beginning to push in, with more clouds towards day break. This should not impact temperatures too much. Lows will drop into to the lower 20s across the interior and middle to upper 20s for most other locations. The NYC metro should only fall into the lower 30s.
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&& .SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY/...
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**Major storm system to impact the area late Tuesday through early Wednesday with heavy rainfall, potential flooding, and strong to damaging winds** No changes have been made to the Flood Watch. A High Wind Warning is now in effect from 6pm Tuesday through 6am Wednesday for Staten Island, Brooklyn, Queens, Long Island, coastal Connecticut along the I-95 corridor, and northern New London County. The high wind watch is no longer in effect. A Wind Advisory is now in effect from 6pm Tuesday through 6am Wednesday for Manhattan, Bronx, NE NJ, Lower Hudson Valley, northern Fairfield, northern New Haven, and northern Middlesex counties. Tuesday will start out dry with increasing clouds as high pressure moves offshore. The storm system will continue intensifying as it begins to move towards the midwest and southeast. The associated upper trough will amplify and begin going negatively tilted allowing for anomalous feed of subtropical moisture along the eastern seaboard. The intense parent low will track towards the Great Lakes through the day which sends a strong frontal system towards the region. The frontal system will then sweep across Tuesday night and should be offshore by day break Wednesday. Models have continued to speed up the timing of both the rainfall and strongest winds over the last 24 hours. Rain should begin developing from west to east by afternoon becoming widespread by mid to late afternoon. Initially the rain will be light to moderate. The rain will become moderate late afternoon into the evening with locally heavy rainfall. The precip may briefly mix with some wet snow well inland at the onset, but warmer air should change any snow over to rain quickly. No accumulation expected. A more widespread heavy rainfall is expected Tuesday night with the peak of the rainfall likely occurring between 00 and 09z. PWATs peak around 1.2-1.3 inches which is near the top of the observed values on the SPC Sounding Climatology for OKX for January 7. The latest 12z HREF shows fairly high probabilities of seeing hourly rainfall rates of around 0.50 per hour. Rates could be briefly locally higher at times, especially if the CAMs projections of a squall line/narrow cold frontal rain band move through along or ahead of the main windshift/cold front. If this band materializes, rainfall rates could briefly touch an inch an hour, but the line will be moving quickly from west to east so that rainfall rate should not last for an actual hour. An isolated rumble of thunder cannot be ruled out. A general consensus of the modeling indicates the rain should begin tapering off west of the city midnight to 3am, in the NYC metro 2am to 4am, and east of the city 3am to 6am. The forecast average rainfall amounts for the event range from 2 to around 3 inches with locally higher amounts possible. This rainfall may lead to flooding with some of the main stem rivers reaching moderate to locally major flood stages. Snow melt, runoff, and higher than normal soil moisture will only add to the threat of flooding. There is a chance for some flash flooding, but widespread urban flooding appears more likely given the average hourly rates of about 0.50 inches per hour. SE winds will increase through the day Tuesday with the strongest winds expected Tuesday night. The low level jet that is modeled is concerning with around 95-100 kt between about 4-5 kft. These winds are well above an inversion, but winds around 1-2ft are quite strong around 50-70kt when the jet peaks overhead. A model consensus has the peak of the low level jet and winds over the area between 03-09z from west to east. The highest winds are still expected near the coast with gusts around 60 mph (in the High Wind Warning). Gusts 45- 55 mph are expected in the wind advisory area away from the immediate coast. Sustained winds could reach 25-35 mph at times Tuesday night. The peak of the winds may occur in just a few hours coinciding with the passage of the low level jet, 10pm-1am north and west of the city, 11pm-2am in the NYC metro, 12am-4am Long Island and Southern CT. Once the front and winds shift more to the S and SW, winds should weaken, which is expected to occur before day break Wednesday. It will then remain breezy on Wednesday with gusts 25-35 mph possible. See Tides/Coastal flooding section for coastal/shoreline impacts. The main axis of moisture and lift will be well offshore on Wednesday. The intense low will lift towards northeast New England and the Maritimes by late in the day with the upper low moving over New England. Instability clouds may remain with the cold pocket aloft. There could be an isolated shower, but for now have gone with a mainly dry forecast in the afternoon. Highs Wednesday range from the upper 40s inland to the lower 50s near the coast.
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&& .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... Another southern stream trough will be moving onshore of the Pacific northwest midweek and tracks quickly to the east coast by Friday night. Before the arrival of another strong low late Friday a weak upper ridge and weak surface high will be across portions of the northeast and Mid Atlantic regions. The upper trough and surface low will be tracking well inland Friday night into Saturday with an occluded low tracking through the area Saturday. With a low level jet of 60-70kt developing Friday night and the low level low over the region, along with precipitable water increasing to 1 to 1.25 inches, another round of moderate to heavy rainfall is becoming more likely Friday night into Saturday morning. Also, with the strong low level and upper dynamics, and elevated CAPE up to 300 J/kg, isolated thunder is becoming more likely during the same timeframe as the heavy rainfall. The is the potential for another flooding event as WPC have placed all the area in at least a marginal risk for excessive rainfall, with an inland portion in a slight risk. Finally, with the strong winds another high wind event is also becoming more likely. The low tracks northward through Eastern Canada late Saturday through Sunday with a strong westerly flow developing across the region as the precipitation comes to an end. Some wrap around moisture may move into the northwest portions Saturday night into Sunday with snow showers, or flurries possible. However, with the westerly flow drying will be likely and precipitation may not make it too far toward the coast. There is a chance of yet another low tracking toward the area for next Monday. The NBM looked reasonable for all parameters Wednesday night through Monday. && .AVIATION /03Z TUESDAY THROUGH SATURDAY/...
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High pressure shifts offshore overnight ahead of an incoming storm system that approaches on Tuesday, and moves across Tuesday night. VFR conditions prevail thru 12-13Z Tue. MVFR cigs develop late Tuesday morning into early Tuesday afternoon, becoming IFR in the late afternoon, with a steady rain developing into the evening push. Moderate to heavy rain likely prevails after 0z Wed for the 36 hr terminals. Light and vrb winds overnight, increasing after 12Z Tue out of the SE. Gusts up to 40 kt possible toward 00Z Wed. LLWS develops towards the Tue eve push. NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty... Timing of category changes during the day Tuesday and Tuesday evening may be off by a couple of hours. OUTLOOK FOR 0Z WEDNESDAY THROUGH SATURDAY... Tuesday night: IFR, with possible LIFR. Rain, locally heavy at times. ESE/SE winds 15-20kt gusts 25-30kt in the afternoon. SE winds, becoming S late and increasing to 25-35kt, gusting 40-50kt, highest winds along the coast. LLWS at night with SE-S winds at 2 kft of 55-75kt. Wednesday: MVFR or lower with rain early in the the morning. Rain ending by noon with conditions improving. S-SW wind 20-25kt gusting 30-40kt. Gusts gradually decrease afternoon into the night. Thursday: VFR. WSW winds 10-15kt with gusts near 20kt. Friday: VFR early, becoming MVFR or lower with rain. Increasing SE winds late. Saturday: MVFR or lower with rain. SE winds 15-25kt G30-35 kt early in the day. 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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Conditions will remain below SCA levels overnight into Tuesday morning. Winds will start to ramp up in the afternoon ahead of an approaching storm system. The system will bring a fairly quick increase in winds to the waters late Tuesday afternoon and evening. The strongest winds are likely to occur overnight into early Wednesday morning. The Storm Watch has been converted to a Storm Warning. Have also started the Warning at 4pm for the ocean and NY Harbor as winds start to increase into gales and then storm force by evening. The warning is in effect elsewhere from 6pm Tue to 6am Wed. Dangerous seas are expected on the ocean, generally 15-20 ft Tuesday night into early Wednesday. Waves on the LI Sound look to reach 5- 8ft, highest east of the Mouth of the CT Ricer. Winds weaken Wednesday morning, but gales are possible into the afternoon on the ocean, eastern LI Bays, and eastern LI Sound, with SCA conditions elsewhere. On-going gales on the ocean waters diminish to SCA levels Wednesday night, meanwhile SCA conditions will remain on the non-ocean waters Wednesday night, falling below by Thursday morning. On the ocean SCA conditions remain into Friday. The sub advisory conditions will be shortlived as a strong low pressure system will be affecting the waters late Friday into Saturday, Gales will be developing on all the waters Friday night with the potential for storm force gusts on the ocean waters late Friday night into Saturday morning. SCA and gale conditions will then continue Saturday night through Sunday.
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&& .HYDROLOGY... No hydrologic impacts are expected through Tuesday morning. A major storm system will bring a total of 2 to around 3 inches of rain with locally higher amounts Tuesday afternoon into early Wednesday. The bulk of the heaviest rain will occur Tuesday night. Widespread urban flooding is possible as runoff from snowmelt and saturated grounds add to the flooding concerns. There is also a chance for flash flooding given the antecedent conditions, but one factor that may inhibit flash flooding is hourly rainfall rates on average around 0.50 inches. River flooding is a bigger concern across NE NJ, Lower Hudson Valley, and interior Southern CT. The runoff from snowmelt, higher than normal stream flows will combine with the heavy rainfall to raise several rivers and streams into moderate flooding. Localized major flooding is possible and current projections take the Saddle River at Lodi into major flooding early Wednesday morning. Ramapo River at Mahwah is forecast to reach moderate flooding Wednesday morning. The Yantic River may also near minor flooding, but a reasonable worst case scenario is for moderate flooding if higher rainfall amounts occur. Many other quick responding rivers and stream will likely reach bankfull and could exceed moderate flooding levels. Hydrologic impacts are possible again Friday night and Saturday with more moderate to heavy rainfall. The exact magnitude and extent of the issues are uncertain this far out. && .TIDES/COASTAL FLOODING...
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Significant ocean dunefront damage expected Wednesday... Widespread minor to moderate coastal flooding with Wed AM high tide... SE storm force expected Tuesday Night into early Wednesday, with a windshift to west southwest gale likely just before the time of high tide for most areas. This windshift will likely limit potential for locally major coastal flooding to just the Great South Bay of LI. Elsewhere, widespread moderate flooding likely for southern bays of NYC/LI and eastern bays of LI, and SE CT. Elsewhere generally minor flooding. Minor coastal flooding possible for the southern bays of W LI, and along W LI Sound Tuesday evening as E/SE increase towards gale force. Along the oceanfront, potential for 15-20 ft surf causing widespread dune erosion and scattered overwashes Wed AM. Localized dune inundation/breaches possible where dunes have been compromised by earlier storm events. 10 to 15 ft breaking surf expected with Wed PM high tide, and with lower water levels, expect dune impacts to be lower magnitude and less widespread. Coastal flood impacts are possible around the times of high tide Friday night and Saturday with another deep low tracking west of the area.
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&& .OKX WATCHES/WARNINGS/ADVISORIES... CT...Flood Watch from Tuesday evening through Wednesday afternoon for CTZ005>012. Wind Advisory from 6 PM Tuesday to 6 AM EST Wednesday for CTZ005>007. High Wind Warning from 6 PM Tuesday to 6 AM EST Wednesday for CTZ008>012. Coastal Flood Advisory from 7 PM Tuesday to noon EST Wednesday for CTZ009-010. Coastal Flood Warning from 6 AM to noon EST Wednesday for CTZ011-012. NY...Flood Watch from Tuesday evening through Wednesday afternoon for NYZ067>071. Wind Advisory from 6 PM Tuesday to 6 AM EST Wednesday for NYZ067>073. High Wind Warning from 6 PM Tuesday to 6 AM EST Wednesday for NYZ074-075-078>081-176>179. Coastal Flood Advisory from 7 PM Tuesday to noon EST Wednesday for NYZ071-078-177. Coastal Flood Advisory from 5 AM to 10 AM EST Wednesday for NYZ072-074-075. Flood Watch from Tuesday evening through Wednesday morning for NYZ072>075-078>081-176>179. Coastal Flood Warning from 4 PM Tuesday to 1 PM EST Wednesday for NYZ079>081-179. Coastal Flood Warning from 5 AM to 9 AM EST Wednesday for NYZ178. NJ...Flood Watch from Tuesday evening through Wednesday afternoon for NJZ002-004-006-103>108. Wind Advisory from 6 PM Tuesday to 6 AM EST Wednesday for NJZ002-004-006-103>108. Coastal Flood Advisory from 5 AM to 10 AM EST Wednesday for NJZ006-104-106-108. MARINE...Storm Warning from 6 PM Tuesday to 6 AM EST Wednesday for ANZ331-332-335-340-345. Storm Warning from 4 PM Tuesday to 6 AM EST Wednesday for ANZ338-350-353-355. && $$ SYNOPSIS...DS/MET NEAR TERM...JE/DS SHORT TERM...DS LONG TERM...MET AVIATION...JE MARINE...DS/MET HYDROLOGY...DS/MET TIDES/COASTAL FLOODING...