018
FXUS61 KOKX 101953
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
353 PM EDT Tue Sep 10 2024

.SYNOPSIS...
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High pressure will strengthen across the local region tonight into Wednesday. High pressure will remain in control thereafter through next Tuesday.
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&& .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
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Dry conditions expected with high pressure in control. Nearly steady trend in the 500mb height tendency. Models are indicating some weak positive vorticity advection moving across tonight. This will present as an increase in clouds in the upper levels. However, on the larger scale the pattern indicates some confluence across the local area, which should strengthen surface high pressure. This will allow for more subsidence. Only expecting the sky to trend from mostly clear to partly cloudy and still think there will be nearly optimal radiational cooling. Surface winds will become very light. Preferred the MAV guidance for min temperatures tonight. This guidance depicts a larger spatial difference between temperatures with cooler temperatures for rural, outlying, and valley areas. Nearly optimal radiational cooling is expected tonight so anticipating spatial differences of near 20 degrees between these cooler outlying locations (lower 40s) and some locations within NYC (lower 60s). For parts of the Pine Barrens and the Lower Hudson Valley as well as interior SW Connecticut, some patchy fog is forecast to develop late tonight into early Wednesday morning. This will be a radiational fog and was placed in the forecast where there is forecast to be saturation as temperatures lower to the dewpoint. Within these areas, the fog likely favor development along the river valleys. The NAM indicated this possibility more than other models such as the HRRR.
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&& .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY/...
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Dry conditions remain Wednesday through Thursday with high pressure remaining in control. Mid levels from Wednesday through Thursday exhibit an overall ridging trend with rising heights. At the surface, high pressure across the region Wednesday will eventually shift offshore Wednesday afternoon into Wednesday night, where it will continue to build. The high pressure will continue building offshore on Thursday. Winds will gradually shift from calm across the interior and light northerly flow along the coast to more of a SE flow across the entire region Wednesday and Thursday. Winds are expected to diminish once again Wednesday night. For max temperatures forecast on Wednesday, used a blend of MAV and MET guidance along with the NBM 50th percentile. This blend keeps coastal locations relatively cooler. For Wednesday night, another optimal night of radiational cooling is expected. Again favored the MAV guidance for min temperatures with their display of more vast temperature differences between outlying and urban temperatures. This guidance indicates lows in the upper 40s for outlying, rural, and valley locations and low to mid 60s within NYC. With warmer temperatures present at 850mb compared to the previous night, this will present an inversion within the soundings in the region. With the more SE low level winds and the diminishing of these winds, there will be more low level moisture to work with. As a result, there is a larger part of the region forecast to have patchy fog develop, but again mostly across the interior and within the Pine Barrens where low level saturation is forecast as temperatures lower to the dewpoint. For Thursday, 850mb temperatures trend slightly warmer than the prior day. Despite low level SE flow, still think temperatures will trend warmer. Used the NBM for max temperature forecast which conveyed warmest temperatures across the interior and NE NJ. These locations will have the least marine influence with the low level winds and thereby should mix more vertically during the afternoon compared to locations to the east.
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&& .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
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The period will feature an extended period of warm and dry weather as a nearly full amplitude ridge remains from eastern Canada into the southeast. Meanwhile high pressure remains near stationary over northern New England to off the New England coast. The high may weaken going into Monday night and Tuesday as low pressure potentially develops off the southeastern coast and tracks north. Low temperatures will be near normal through the period while daytime high temperatures will be up to 5 degrees above normal Friday through Sunday, and close to normal Monday and Tuesday with more of an easterly flow becoming established. There is the chance for valley fog and radiational fog each night Thursday night, through Monday night. And, at this time have only included in the weather grids Thursday night through Saturday night. The NBM was followed through the extended period.
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&& .AVIATION /20Z TUESDAY THROUGH SUNDAY/...
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VFR as high pressure builds in. NW flow under 10 kt expected for most. Sea breeze has pushed through KJFK and will likely hold just north of the terminal. It is also heading towards KISP, but thinking now is it will likely slow and hold just south of the terminal. Winds become light N-NE late this evening/overnight. S/SE sea breezes are expected on Wednesday. Any locations that don`t see a sea breeze will eventually become S/SE later in the afternoon with the synoptic flow. ...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty... An ocnl gust 15-18 kt possible this afternoon, mainly for KEWR. The sea breeze has pushed through KJFK and will likely stay north of the terminal now for at least a couple of hours. Have put NW flow in a TEMPO 21 through 23z. OUTLOOK FOR 18Z WEDNESDAY THROUGH SATURDAY... Mainly VFR. Some late night/early morning low clouds/patchy fog may be possible at terminals outside of NYC Wednesday through Saturday night. 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 on the forecast waters remain well below SCA thresholds with high pressure staying in control for the short term period through Thursday. With high pressure remaining in control winds and seas remain below advisory levels Thursday night through Monday.
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&& .HYDROLOGY...
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No hydrologic impacts are expected through next Tuesday with high pressure in control.
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&& .TIDES/COASTAL FLOODING...
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There is a low rip current risk at the ocean beaches through Thursday.
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&& .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...JM/MET NEAR TERM...JM SHORT TERM...JM LONG TERM...MET AVIATION...JT MARINE...JM/MET HYDROLOGY...MET TIDES/COASTAL FLOODING...MET