000
FXUS61 KOKX 181458
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
958 AM EST Mon Dec 18 2023

.SYNOPSIS...
Strong low pressure passes through the area today. The low then
tracks north into southeastern Canada tonight with high pressure
slowly building in during Tuesday. High pressure will then remain in
control through the upcoming weekend.

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.NEAR TERM /UNTIL 6 PM THIS EVENING/...
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Changes with this update: The high wind warning for Queens, Brooklyn, and Nassau counties has been cancelled. The wind advisory for Hudson, Bergen, Essex, Union, Westchester, Manhattan, Bronx, and Richmond Counties. A broad 983 mb low is situated over eastern upstate NY with the center extending down across the NYC metro and off the NJ shore. The strongest winds have shifted east and will continue across S CT and eastern Long Island. The LLJ should shift further east through the rest of the morning. A middle level dry slot has allowed the heaviest rain to end over NE NJ, Lower Hudson Valley, and NYC metro. A band of heavy rain with isolated thunder continues across eastern Long Island and SE CT. This band should shift east of the area in the next few hours. The low should slowly pivot across the region into the afternoon. Bands of rain may should redevelop on the backside of the low into the early afternoon with some additional locally moderate to briefly heavy rainfall possible. The threat for high winds likely ends late this morning. There should be a brief lull in gusty winds with the center of the broad low over the area. Gusty W winds will follow the passage of the low center with fairly steep pressure rises. However, gusts 25-40 mph are expected, under advisory levels. No changes were made to the Flood Watch. Multiple rivers and stream across NE NJ and Lower Hudson Valley are in flood with several reaching moderate flood stage and even one river currently in Major (Saddle River ad Ridgewood). Mild with high temperatures in the upper 50s to lower 60s. A few sites have broken their daily high temperature records and RERs will be sent later this morning. See the climate section below for more details.
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&& .SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/... The low will be north of the area tonight with a brief break in precipitation. Wrap around moisture in the back side of the storm with the approach of a closed mid-level will bring a chance of rain/snow showers well NW of the city late tonight into Tuesday morning. There may even be slight coating of snow in the higher terrain of Western Orange County. Dry for Tuesday night with the flow aloft becoming anticyclonic and surface high pressure building in. && .LONG TERM /WEDNESDAY 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 during Tuesday night will remain over the area through next weekend. This will sustain a period of dry weather Wednesday through Sunday. 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 /15Z MONDAY THROUGH FRIDAY/...
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HIGH IMPACT AVIATION EVENT TODAY... Strong low pressure approaches tracks near the region this morning and then lifts to the north and east, dragging a cold front through this afternoon. Low pressure is currently over the region, allowing for a bit of a lull in the conditions. Some terminals are improving to VFR and the winds have dropped off a bit. However, once the low tracks east of the region, conditions should deteriorate once again. Do not think they will be as bad as earlier, but MVFR conditions or lower is expected and winds will pick up again, with gusts around 30 to 35 kt range. This should occur around 17Z for the metro terminals and KHPN and KSWF, 18Z for KISP and KBDR, and 20-21Z for KGON. Widespread IFR/LIFR conditions this 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 should follow by early evening. Cigs on Tuesday may occasionally go MVFR. Peak S/SE winds occurring now thru mid morning or so, 20-30kt G30-50kt, with strongest along the coast. Slow improvement late morning through the afternoon, with winds veering to S/SW, then W/NW around 20kt G30-35kt in the afternoon into early evening. Winds will then gradually diminish and back to the SW G20-25kt Monday evening. Gusts 20 to 25 kt linger through Tuesday. NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty... Isolated 45 to 50 kt gusts thru 15Z this morning, especially at KJFK and KLGA. Gusts after 13Z could be more occasional than frequent until low passes to the east in the early afternoon. Timing of flight categories could vary by 1-2 hours. OUTLOOK FOR 12Z TUESDAY THROUGH FRIDAY... Tuesday: Mainly VFR, brief MVFR cigs possible. 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...
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Have cancelled the Storm Warning on the NY Harbor and ocean west of Fire Island Inlet and replaced with a gale warning. The strongest winds are shifting to the eastern waters this morning. The ongoing Storm Warnings will gradually be converted to gale warnings on the ocean and possibly LI Bays and eastern Sound with SCAs elsewhere. Gales should then prevail this afternoon on the ocean and perhaps over the eastern bays and eastern LI Sound. Otherwise, solid SCA conditions this afternoon for the rest of the waters. Ocean seas are expected to range roughly up to 16-21ft during the day today. All waters will probably be experiencing SCA conds by midnight tonight, then as winds continue to subside, conditions should be below advisory thresholds by the end of tonight on the non-ocean waters. Seas remain elevated on the ocean through at least the end of the week as long period swells from an offshore storm keep waves elevated.
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&& .HYDROLOGY...
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The heaviest rain has shifted to eastern Long Island and southeast CT. Additional moderate to locally heavy rain is possible late this morning into the afternoon. This could add to the already ongoing river and stream flooding across NE NJ and Lower Hudson Valley. Several rivers and streams are in minor to moderate flooding with Saddle River at Ridgewood current in major. Total rainfall amounts have ranged from 1.5 to 4.5 inches. An additional 0.5 to 1 inch is possible with the higher totals across eastern Long Island and Southeast CT. The Flood Watch remains in effect tonight through this afternoon. Residual river flooding will then continue tonight as levels subside. Afterwards, no hydrologic impacts expected through next weekend.
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&& .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 today. 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 this morning. A later timing of windshift closer to today`s early 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 this afternoon`s 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 today (8-12ft for NYC beachfront), which combined with elevated water levels, will likely result in widespread dune erosion and scattered overwashes. && .CLIMATE... Record high temperatures for December 18th... EWR...64/1937 BDR...61/1937 NYC...63/1964 LGA...63/2006 JFK...64/1984 ISP...59/1984 && .OKX WATCHES/WARNINGS/ADVISORIES...
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CT...Flood Watch until 5 PM EST this afternoon for CTZ005>007- 009>011. Wind Advisory until noon EST today for CTZ005>007. High Wind Warning until noon EST today for CTZ008>012. Coastal Flood Warning until 6 PM EST this evening for CTZ009>012. NY...Flood Watch until 5 PM EST this afternoon for NYZ067>075-176- 178. High Wind Warning until noon EST today for NYZ078>081. Coastal Flood Warning until 6 PM EST this evening for NYZ071- 079>081-178-179. Coastal Flood Warning until 4 PM EST this afternoon for NYZ074- 075. Coastal Flood Advisory until 6 PM EST this evening for NYZ072- 073-078-176-177. NJ...Flood Watch until 5 PM EST this afternoon for NJZ002-004-006- 103>108. Coastal Flood Warning until 4 PM EST this afternoon for NJZ006- 104-106-108. MARINE...Storm Warning until 1 PM EST this afternoon for ANZ331-332-335- 340-345-350-353. Gale Warning until 6 PM EST this evening for ANZ338. Gale Warning until 9 PM EST this evening for ANZ355.
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&& $$ SYNOPSIS...JC/JP NEAR TERM...JC/DS SHORT TERM...JC LONG TERM...JP AVIATION...DR/DW/JP MARINE...JC/JP HYDROLOGY...JC/JP TIDES/COASTAL FLOODING... CLIMATE...