Area Forecast Discussion
Issued by NWS Upton, NY

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601 FXUS61 KOKX 031428 AFDOKX Area Forecast Discussion National Weather Service New York NY 1028 AM EDT Mon Jun 3 2024 .SYNOPSIS... A weak disturbance passes offshore early today, with high pressure then gradually building down from New England into midweek. High pressure moves out into the Atlantic Wednesday night. A warm front approaches thereafter and moves within the region Thursday. The warm front then moves north, leaving the area with an approaching central area of low pressure for Friday. The low meanders near the area going into the upcoming weekend. && .NEAR TERM /THROUGH TONIGHT/...
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Forecast remains on track this morning. A dry and mild start to the day with temperatures in the 60s and lower 70s. Any early morning showers have come to and end with drying conditions as ridging begins to return and a 1020 mb high over Quebec gradually noses south into midweek and sets up an onshore flow. Cloud cover should begin to break up, especially away from the coast, and bring a return to sunshine by early afternoon with the exiting of the disturbance. With ample sun, temperatures will once again rise into the low to middle 80s for much of the area. Hints of instability off to the west this afternoon may be able to instigate a few pop up showers or thunderstorms with daytime heating, but coverage looks limited given dry air, lack of significant forcing, and only marginal instability. Maintained a slight chance (20%) for this late afternoon activity, but confined to areas from NYC on west. BUFKIT soundings do indicate DCAPE values approaching 1000 J/kg given the dry low levels and steepening lapse rates, so not out of the question that any thunderstorm that goes up could produce an isolated damaging wind gust. Still, severe threat looks minimal and SPC has maintained the local area in a general thunder. Any convection weakens by evening with loss of heating and as heights begin to recover behind the shortwave begin to ridge a bit more. Lows tonight will be in the mid 50s to low 60s, or near just to above normal for early June.
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&& .SHORT TERM /TUESDAY THROUGH WEDNESDAY/... Ridging aloft continues to shift east on Tuesday and Wednesday with surface high pressure situated off to the north. Dry on Tuesday with high pressure sliding down the New England coast keeping fair weather conditions in place. The developing onshore flow Tuesday will keep coastal locales a bit cooler than recent days, with highs likely in the low to mid 70s during the afternoon. Away from this influence, mainly the far interior and areas west of the Hudson River, lower 80s is where temperatures top out. A vigorous shortwave rounding the base of a sprawling upper low over Central Canada will eject into the Midwest midweek, spelling an end to the relatively quiet pattern that has been in place. Rain chances increase Wednesday afternoon and evening with the approach of an associated warm front from the south and west. While the bulk of the day appears dry, global ensembles have trended a bit quicker with this WAA, and will need to continue to monitor these trends. It`s just as possible however any wet weather holds off until later Wednesday night. Temperatures on Wednesday will be held down some by the increasing cloud cover and persistent onshore flow, with highs in the 70s for most. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... Main points * Heavy showers and thunderstorms looking likely for Wednesday night into Thursday. Possibility for mainly minor flooding. See hydro section for more details. * Periodic shower activity for Friday and into upcoming weekend. Possible thunderstorms at times as well. * Temperatures will not depart much from normal values this time of year. Synoptic pattern shows a transition from mid level ridge to a longwave mid level trough that eventually closes off. The mid level cutoff low then moves towards the local region towards the end of the week and into the upcoming weekend. The base of the trough and its axis potentially get within the local region by Sunday night. This analysis is from the LREF grand ensemble. Here is how the forecast changed compared to the previous forecast: Temperatures no significant changes. Max temperature forecast lower 80s NYC and locations N&W Thursday and Friday. Min temperatures forecast mid 50s to around 60 for much of area Friday night and Saturday night, lower 60s for NYC. POPs trended up Wednesday night, overnight, now into likely NYC and locations N&W, overnight Wed night into early Thursday AM, 6-12Z Thursday, likely POPs all forecast region 12-18Z Thursday, just about entire area 18Z Thursday - 00Z Friday. Otherwise no significant changes. Despite marginal elevated instability in the Thursday into Friday timeframe, there is potential for some low to mid level omega to aid in vertical lift, so that is why there are higher chances of thunderstorms and wanted to have higher than slight chance thunder. && .AVIATION /14Z MONDAY THROUGH FRIDAY/...
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Offshore high pressure remains through the TAF period. Mainly VFR conditions are expected through the TAF period. A pop-up shower or thunderstorm will be possible for this afternoon, mainly in the latter half in and around NYC terminals, KHPN and KSWF. There is a low possibility of MVFR with any shower or thunderstorm as well as a strong isolated wind gust. Winds overall will be quite light through the TAF period with wind speeds under 10 kts. Wind direction will be quite variable this morning, followed by more of a sea breeze circulation for most terminals during the afternoon before weakening going into early this evening. For tonight, wind direction becomes variable again. A more east to southeast wind is expected to develop going into early Tuesday. NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty... Low confidence in wind direction forecast today. Wind direction may turn out to be more variable for today with occasional large differences from forecast possible this afternoon. OUTLOOK FOR 12Z TUESDAY THROUGH FRIDAY... Tuesday: VFR. Wednesday: VFR during the day. MVFR or lower possible late day into the night with chances of showers and thunderstorms. Thursday: MVFR or lower possible in rain showers, possible thunderstorms afternoon into night. Friday: MVFR possible at times. A chance of showers with thunderstorms possible. Detailed information, including hourly TAF wind component forecasts, can be found at: https:/www.weather.gov/zny/n90
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&& .MARINE... Conditions will remain below SCA levels through late week with seas on the ocean generally 3 ft or less. && .HYDROLOGY... There are no hydrologic concerns through Wednesday. With precipitable waters potentially approaching near 2 inches Wednesday night into Thursday, some showers and especially any thunderstorms could have heavy downpours. The potentially torrential rain could cause minor flooding in low lying, urban and poor drainage areas. With sufficient movement to showers and thunderstorms, would think much of the flooding potential would be minor. && .TIDES/COASTAL FLOODING... Coastal flood statement in effect for South Shore Bays, Southern Nassau NY 4PM this afternoon to 8PM this evening. Coastal flood statement in effect for Southern Westchester NY, Southern Fairfield CT 8PM this evening to 12AM tonight. The indication here seen in Stevens and ETSS indicates these locations are touching or slightly exceeding minor coastal flood benchmarks for this evening high tide. With the approach of a new moon this week, astronomical levels will be on the rise. With winds becoming more southerly and eventually southeasterly, this will allow for increasing surge this week. As a result, some locations especially across the Western LI Sound and LI South Shore back bays may see minor coastal flooding, starting with Monday afternoon`s high tide cycle and becoming more widespread Tuesday night and Wednesday night. Stevens guidance shows minor flood benchmarks being approached, or exceeded by a few tenths for a few spots along southern Nassau and the Western Sound. Thus, trends will need to be monitored in subsequent cycles as minor coastal flooding will become more likely for these areas Tuesday into Wed. There is a low rip current risk through Tuesday due to low seas on the ocean and winds mainly 10 kt or less. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...JM/DR NEAR TERM...BC/DR SHORT TERM...DR LONG TERM...JM AVIATION...JM/DW MARINE...JM/DR HYDROLOGY...JM/DR TIDES/COASTAL FLOODING...