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FXUS61 KOKX 230222
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
1022 PM EDT Sun Oct 22 2023

.SYNOPSIS...
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Strong low pressure over the Canadian Maritimes will gradually move farther out into the north Atlantic overnight as high pressure build from the west. The high will be along the coast on Tuesday, then shift just offshore and allow a warm front to pass to the north late Tuesday into Tuesday night. The high will remain in place through Friday, then drift southward this weekend as low pressure passes well to the north and drags one weakening cold front toward the area this weekend. Another weak cold front approaching from the west may get close enough to bring the next chance of rain late Sunday or Sunday night.
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&& .NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
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Steep pressure gradient between low pressure northeast of the region across the Canadian Maritimes and high pressure near the western Great Lakes will be gradually weakening overnight, and gusty NW flow will subside as a result. A mid-level vorticity maximum was tracking south of Long Island. The associated cyclonic flow aloft will keep cloud cover with us tonight. At the surface, a trough moves across at night, allowing for the winds to take on a more northerly component. The pressure gradient weakens tonight with the low moving farther away from the local region and the high pressure area to the west getting closer. Less cyclonic flow is expected by late tonight, allowing for clouds to decrease. With the winds staying up though, radiational cooling will be mitigated. Forecast low temps are in the 40s.
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&& .SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/... For Monday, high pressure will be more of an influence in the region with greater subsidence and a further decrease of the pressure gradient. Less gusty winds and more sun will lead to a relatively warmer day. Forecast high temperatures are more in the upper 50s to lower 60s, which will be closer to normal for this time of year. For Monday night, while surface high pressure builds overhead, models depict a weak shortwave moving in at night. Most guidance agrees with an increase in cloud cover at night because of this. The 12Z HREF member mean is showing max cloud cover Monday night between 40-50%, building west to east along the track of the shortwave. The increased cloud cover may inhibit significant radiational cooling. Took a blend of MOS and did not take the coldest of the MOS because of this. Forecast lows still range mainly in the mid 30s to upper 40s. Forecast lows still have outlying areas and interior locations in the lower 30s. Frost with low level saturation is forecast for north and west of NYC and parts of the Pine Barrens but confidence is not high due to uncertainty in the maximum extent of cloud coverage Monday night. Parts of the Lower Hudson Valley have forecast temperatures near freezing. && .LONG TERM /TUESDAY THROUGH SUNDAY/...
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A significant warmup expected going into mid week after sfc high pressure along the coast shifts offshore on Tue, and a warm front passes well to the north late Tue into Tue night. Expecting near record warmth mid to late week, as H5 heights reach 588 dm on Thu with H5-10 thicknesses at least 567 dm Thu- Sat. For temps took a 12Z GFS MOS/00Z ECMWF MOS blend which for the most part was even warmer than the NBM 75th percentile...with some modest downslope component to the flow (WSW) can`t see why some spots west of NYC wouldn`t push 80 for highs on at least Thu. Thicknesses remain high into Sat but heights fall aloft, and guidance does show a mostly dry cool front sagging southward toward the area this weekend, so it is possible that Fri/Sat may be not quite as warm. Meanwhile GFS likely too fast with cold frontal approach from the west on Sunday and lowering heights aloft too quickly, while other guidance is slower. As a result have kept most of the weekend dry, with chance PoP holding off until Sunday night.
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&& .AVIATION /03Z MONDAY THROUGH FRIDAY/...
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High pressure builds in from the west through Monday. VFR. There is a low chance of high end MVFR ceilings at KSWF late tonight. A gusty NW flow continues until around 06Z, and then both sustained winds and gusts gradually diminish. Gusts may become more occasional after 04Z before ending 06Z to 09Z. Monday winds become more northerly. ...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty... No unscheduled amendments expected. OUTLOOK FOR 00Z TUESDAY THROUGH FRIDAY... Monday night 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... SCA remains in effect through tonight for all waters for wind gusts 25-30 kt, and through noon Monday on the ocean where residual 5+ ft seas are still likely through the morning. Quiet conditions expected thereafter with high pressure in control. Persistent SW flow 15 kt on Wed could build ocean seas up to 4 ft during that time frame. Swells from distant Tammy could start to arrive on the ocean waters very late in the fcst period (Fri night). && .HYDROLOGY... No hydrologic impacts expected through the week. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...Small Craft Advisory until 6 AM EDT Monday for ANZ331-332-335- 338-340-345. Small Craft Advisory until noon EDT Monday for ANZ350-353-355. && $$ SYNOPSIS...BG/BR NEAR TERM...BG/BR/MET SHORT TERM...BR LONG TERM...BG AVIATION...MET MARINE...BG/BR HYDROLOGY...BG/BR