258
FXUS61 KOKX 171951
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
351 PM EDT Fri May 17 2024

.SYNOPSIS...
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Weak high pressure remains over the region tonight through Saturday night as a weakening trough of low pressure approaches and then dissipates by Saturday evening. Otherwise, high pressure generally remains in control through the middle of next week. A cold front approaches late in the week.
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&& .NEAR TERM /THROUGH SATURDAY/...
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With the longwave global waves remaining nearly stationary tonight through Saturday night there will be little movement of surface systems. A weak low will remain south of Nova Scotia and meander through Saturday as a weak surface ridge from high pressure over southeastern Canada extends along the east coast. A northeast to east flow will bring low level moisture into region tonight into Saturday morning. And with some weak low level convergence and lift light drizzle will be possible. Meanwhile, a weak surface trough will be moving very slowly east and weaken tonight into Saturday. And by Saturday morning a few showers may move into the western portion of the region with some weak lift with the trough. The offshore low weakens Saturday afternoon with lift ending, so end the chances for drizzle by then. With little airmass change overnight temperatures will be similar tonight to Friday morning`s lows. And with more clouds and the easterly flow high temperatures Saturday will be around 5 degrees below seasonal normals.
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&& .SHORT TERM /SATURDAY NIGHT/...
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The weakening surface trough to the west may move into the region, and into the surface ridge, and then dissipate Saturday night. Any lift and showers with this system will then be ending. Otherwise, weak high pressure remains in control. Once again with little airmass change temperatures Saturday night will be in the lower to mid 50s across the region.
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&& .LONG TERM /SUNDAY THROUGH FRIDAY/...
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*Key Points* *Mainly dry with above temperatures Sunday through next week. *A cold front approaches late in the week with the next chance at showers, possibly thunderstorms, Wednesday night through Thursday. Relatively quiet weather is expected Sunday through the middle of the week. Ridging both aloft and the surface will begin building over the northeast on Sunday and should remain in control through Wednesday. The modeling continues to signal the break down of the ridge late Wednesday as an upper level trough heads east from the Rockies towards the Great Lakes. There is relatively good agreement for this shortwave to move across the region sometime late in the week. However, the guidance is not in agreement on its amplitude and timing, which impacts the strength of a cold front. This cold front should approach late in the week bringing an increase in chances for showers and possibly Thunderstorms. Will continue to use the NBM given the time range, which looked reasonable for PoPs Wednesday night into Thursday night. The consensus indicates the front should be moving through on Thursday, but this could speed up or slow down, especially with uncertainty with the aforementioned trough and weakening of the ridge. Mainly used the NBM deterministic for temperatures, but blended in the 50th percentile for Monday through Thursday. There is a fair amount of temperature spread, and the NBM deterministic is lying closer to the 25th percentile. This is most prominent away from the immediate coast where temperatures typically are warmer during onshore flow days. The onshore flow should keep coastal locations in the upper 60s to lower 70s, but elsewhere should be able to warm into the upper 70s and lower 80s. Temperatures could be even warmer (middle to upper 80s away from the coast), especially if the flow takes on a more westerly component ahead of the front Wednesday or Thursday.
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&& .AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
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Weak high pressure will be in place through Saturday. VFR through this evening. MVFR ceilings will return late tonight, first across the eastern terminals during the early morning hours, and then around 14-15Z Saturday for the NYC and Lower Hudson terminals. Timing will probably need to be refined. Mostly southerly winds under 10kt with sea breezes, lasting into early evening before winds become light and variable for a short time tonight. Winds then prevail mostly NE overnight. Winds remain mostly NE 5-10kt on Saturday. ...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty... Low chance that sea breeze does not reach KEWR and KTEB, with winds remaining more easterly there into early evening. OUTLOOK FOR 18Z SATURDAY THROUGH WEDNESDAY... Saturday PM: MVFR, mainly east of the city terminals. Sunday...MVFR in the morning, then VFR. MVFR or lower could persist at the eastern terminals all day. Monday...MVFR/IFR in the morning, then VFR in the afternoon. Tuesday-Wednesday...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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Ocean seas east of Fire Island Inlet remain elevated, at 5 to 6 feet, with a east to southeast 8 second swell from weak low pressure meandering south of Nova Scotia. The low weakens further during Saturday. Ocean seas will take awhile to subside, and have extended the SCA from Fire Island to Moriches Inlet until midnight, and to the east of Moriches Inlet until 1000 AM Saturday. Then Saturday afternoon and Saturday night winds and seas remain below advisory levels. On the non ocean waters winds and seas remain below advisory levels tonight through Saturday night. A weak pressure gradient over the waters will lead to conditions below SCA levels Sunday through the middle of next week.
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&& .HYDROLOGY...
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There are no hydrologic issues through the middle of next week.
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&& .OKX WATCHES/WARNINGS/ADVISORIES...
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CT...None. NY...None. NJ...None. MARINE...Small Craft Advisory until 10 AM EDT Saturday for ANZ350. Small Craft Advisory until midnight EDT tonight for ANZ353.
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&& $$ SYNOPSIS...DS/MET NEAR TERM...MET SHORT TERM...MET LONG TERM...DS AVIATION...JC MARINE...DS/MET HYDROLOGY...DS/MET