000
FXUS61 KOKX 180056
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
756 PM EST Sun Dec 17 2023

.SYNOPSIS...
Strong low pressure along the Carolina coast this evening
approaches form the south tonight and passes through the region
during Monday. The low tracks north of the area Monday night.
Low pressure moves away from the area on Tuesday with high
pressure building in. High pressure will remain in control
through next weekend.

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.NEAR TERM /THROUGH MONDAY/...
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Added isolated thunderstorms to the forecast as a thunderstorm moved onshore and was observed over the NWS office just after 4 pm. Additionally, dew points across the area are rising into the 50s, and closing in on middle 50s for Long Island. Also, increased POPs over the eastern areas as the current batch of showers moves out, but another areas of showers looks to move over those areas by around 830 this evening from the south. Otherwise, the forecast is on track. Scattered areas of light rain have become more widespread this evening as moisture levels increase, and in response to the approach of a northern stream upper trough. Rainfall then becomes categorical later tonight and overnight as deepening low pressure along the southeastern coast this evening approaches the region from the south. Timing and track of the low remain fairly consistent with the previous forecast. With the low continuing to rapidly deepen tonight and a strong low level jet developing on the eastern side of the low, a period of moderate to heavy rainfall is expected late tonight into Monday morning. Some of the highest rainfall totals are expected across portions of northeastern New Jersey into the lower Hudson Valley, and even into southwestern Connecticut (Fairfield County) with strong southeasterly flow enhancing lift on the upslope sides of the higher terrain. Rainfall totals have increased slightly across these areas. Weak elevated instability, especially late tonight into Monday morning, will also enhance rainfall, as isolated thunder remains possible. A flood Watch remains in effect tonight through Monday afternoon. A period of high winds and strong gust also remain likely late tonight into early Monday morning as a strong low level jet of 60-85kt moves over the eastern regions. And a High Wind Warning remains in effect for the coastal locations. With a slightly more western track of the low and winds gusts possibly reaching advisory levels farther west and north, have expanded the winds advisory to include Eastern Bergen, Eastern Essex, and Eastern Union Counties. While the period of the strongest winds and gusts will be a few hours late tonight into early Monday morning, the timing of the Warning and Advisory remain as initially issued.
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&& .SHORT TERM /MONDAY NIGHT/... The low will be north of the area by Monday night with a brief break in precipitation. Wrap around moisture in the back side of the low will maintain chance and slight chance probabilities Monday night. With some colder air wrapping into the northwest sections a few snow showers and flurries will be possible. There may even be slight coating of snow in the higher terrain of Western Orange County. && .LONG TERM /TUESDAY THROUGH SUNDAY/... Upper level low over the eastern Great Lakes region will weaken into a trough as it moves toward the forecast area. A weak area of low pressure looks to form along the frontal boundary offshore, and a blocking pattern will then set up as the trough becomes an upper level low once again and will interact with the weak surface low offshore, becoming vertically stacked by the middle of the week. With a blocked pattern over the region, the surface high that builds in late Tuesday into Tuesday night will remain over the area through next weekend. The only chance for any precipitation for this time frame is during the day on Tuesday. This will be due to the trough aloft and one at the surface that will move through. These features may provide enough lift for some precipitation, however any precipitation will be light. It will be cold enough well inland Tuesday morning for some snow flakes to fall, or snow mixed with rain, but little if any accumulation is expected. The area will be on the eastern side of the high during much of the week, with a northwest to northerly flow for much time. This will lead to seasonable temperatures with highs in the 40s. && .AVIATION /00Z MONDAY THROUGH FRIDAY/...
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HIGH IMPACT AVIATION EVENT OVERNIGHT INTO MONDAY... Deepening low pressure tracks up the East Coast through Monday. Overall trend will be for lowering conditions as moderate to heavy rain overspreads the area from south to north through the early morning hours. Expect widespread IFR/LIFR conditions through Monday morning with improvement behind the departing surface low and cold front in the afternoon. Conditions are forecast to improve to MVFR in the afternoon, becoming VFR by late afternoon for all but KGON, which could take into early Monday evening. E/SE around 10 to 15 kt with gusts up to 20 kt through this evening. Winds steadily ramp up tonight after 03Z Monday, with strongest winds after 06Z Monday. SE winds increasing to 20-30kt G35-55kt, strongest along the coast. Slow improvement late Monday morning through the afternoon, with winds gradually decreasing in the afternoon and into the evening. Winds become S/SW Monday morning then shift to the W/NW in the afternoon into early evening. ...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty... E/NE winds around 10 kt early at KLGA, shifting to the E/SE by 00Z. Isolated 50 kt gusts late tonight into Monday morning (by 12Z), especially at KJFK and KLGA. Gusts after 13Z Monday could be more occasional than frequent until low passes to the east in the early afternoon. OUTLOOK FOR 00Z TUESDAY THROUGH FRIDAY... Monday Night: VFR, possibly MVFR to start at KGON. W/SW 10-15 G20-25kt in the evening. Tuesday: Chance of flurries mainly north and west of the NYC terminals early, then a few rain or snow showers possible along the coast during the afternoon. MVFR, possibly IFR, especially in any snow showers. WNW G20-25kt in the afternoon. Wednesday through Friday: VFR. Detailed information, including hourly TAF wind component forecasts, can be found at: https:/www.weather.gov/zny/n90
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&& .MARINE... With winds, gusts, and seas expected to increase tonight, especially late tonight, have begun the Storm Warning for all the forecast waters with the evening issuance. The strongest winds and gusts will likely continue into Monday morning before diminishing rather quickly from west to east midday through Monday afternoon. The highest winds will likely be after 100 AM through about 1000 AM Monday. Once the Storm Force gusts diminish there will be a brief period of gale force gusts before winds diminish to SCA levels Monday evening, wind winds falling below advisory levels late Monday night, ending by Tuesday morning. However, very high ocean seas will remain through Monday night. An extended period of SCA is expected on the ocean waters through at least the end of the week as long period swells from an offshore storm keep waves elevated. Wave heights on the ocean will range from 8 to 13 ft Tuesday morning will slowly diminish through Thursday morning to around 5 ft. They then may build again slowly through the end of the week. Winds should remain below SCA criteria, except for Tuesday on the ocean waters as a tight pressure gradient weakens with high pressure building in. && .HYDROLOGY... A total of 2 to nearly 5 inches of rainfall is expected through Monday afternoon, with most of this falling from late tonight through Monday morning. Locally higher amounts, as much as 5 to 6 inches, are possible across portions of northeastern New Jersey, into the Lower Hudson Valley, and possibly into portions of Southwestern Connecticut (Fairfield County). The location of the highest amounts will be dependent on the track of the low, and will be more likely on the upslope sides of higher terrain. With flooding of fast responding streams, possibly reaching moderate flooding benchmarks, and flooding of poor drainage and urban areas, and localized to scattered flash flooding becoming more likely, the Flood Watch remains in effect tonight through Monday afternoon. A few of the faster responding stream of northeastern New Jersey may even reach major flooding benchmarks. Afterwards, no hydrologic impacts expected through next weekend. && .TIDES/COASTAL FLOODING... Coastal flood warnings continue for southern Queens, southern and eastern portions of LI and coastal CT, and expanded for NE NJ as widespread moderate coastal flooding is likely with the daytime high tide cycle on Monday. This includes the tidally affected rivers, particularly Hudson and Hackensack rivers, where the surge is favored to be forced upstream by the strong southerly flow. There is potential for locally major flood thresholds to be reached for southern Queens, SW LI and twin forks, if windshift occurs near or after the time of high tide. Elsewhere minor to locally moderate coastal flood potential exists for NE LI and northern portions of NYC. Peak surge of 3 1/2 to 5 ft will likely be between high tidal cycles Monday morning. A later timing of windshift closer to the early Monday afternoon time of high tide will aid potential for major flood thresholds to be reached or exceeded for the most vulnerable southern Queens, SW and E LI portions of the area. This will likely not be evident until the time of high tide is approaching. Forecast is a blend of 75th percentile of PETSS, Stevens, and deterministic ESTOFS. Heavy rainfall and/or runoff coinciding with the Monday afternoon high tides will exacerbate street and property flooding issues along the coast and tidally affected rivers. Along the ocean beachfront, potential exists for 12-16 ft breakers Sunday overnight into Monday (8-12ft for NYC beachfront), which combined with elevated water levels, will likely result in widespread dune erosion and scattered overwashes. Finally, minor coastal flooding possible with tonight`s high tide mainly for southern Queens, SW LI and coastal Westchester and SW CT. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...Flood Watch through Monday afternoon for CTZ005>007-009>011. Wind Advisory from midnight tonight to noon EST Monday for CTZ005>007. High Wind Warning from midnight tonight to noon EST Monday for CTZ008>012. Coastal Flood Warning from 10 PM this evening to 6 PM EST Monday for CTZ009>012. NY...Flood Watch through Monday afternoon for NYZ067>075-176-178. Wind Advisory from midnight tonight to noon EST Monday for NYZ071>074. High Wind Warning from midnight tonight to noon EST Monday for NYZ075-078>081-176>179. Coastal Flood Warning from 10 PM this evening to 6 PM EST Monday for NYZ071. Coastal Flood Warning from 10 AM to 4 PM EST Monday for NYZ074- 075. Coastal Flood Advisory from 10 PM this evening to 6 PM EST Monday for NYZ072-073-078-176-177. Coastal Flood Warning from 11 PM this evening to 6 PM EST Monday for NYZ079-081. Coastal Flood Warning until 6 PM EST Monday for NYZ080-178-179. NJ...Flood Watch through Monday afternoon for NJZ002-004-006- 103>108. Wind Advisory from midnight tonight to noon EST Monday for NJZ006-104-106-108. Coastal Flood Warning from 10 AM to 4 PM EST Monday for NJZ006- 104-106-108. MARINE...Storm Warning until 1 PM EST Monday for ANZ331-332-335-338-340- 345-350-353-355. && $$ SYNOPSIS...JP/MET NEAR TERM...JP/MET SHORT TERM...MET LONG TERM...JP AVIATION...DW MARINE...JP/MET HYDROLOGY...JP/MET TIDES/COASTAL FLOODING...