Area Forecast Discussion
Issued by NWS Upton, NY

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262 FXUS61 KOKX 300304 AFDOKX Area Forecast Discussion National Weather Service New York NY 1104 PM EDT Sat Jun 29 2024 .SYNOPSIS... A warm front moves northeast of the region going into this evening. A cold front approaches tonight into early Sunday and moves across the area Sunday afternoon into Sunday night. High pressure builds into the area from the northwest Monday through Tuesday and pushes offshore late Tuesday into Tuesday night. A warm front lifts north of the area on Wednesday. A cold front approaches Wednesday night and stalls near the area through the end of next week into the first half of next weekend. && .NEAR TERM /UNTIL 8 AM SUNDAY MORNING/...
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Line of showers associated with some middle level energy and a warm front continues to weaken as it heads over Long Island. The warm front will lift north of the area into early Sunday morning. There is very little instability, but it does look like elevated CAPE increases overnight. Some regeneration of showers and possibly a thunderstorm looks probable especially near the coast. Elsewhere, scattered showers with maybe a rumble of thunder are possible. Brief downpours are possible, but the forward speed will prevent any flooding issues despite the increasing subtropical moisture over the area. Think the strong low level flow will prevent any fog development, but a few areas could see patchy fog along the coast overnight. It will be muggy with lows struggling to fall out of the 70s.
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&& .SHORT TERM /8 AM SUNDAY MORNING THROUGH MONDAY/... Large scale numerical weather prediction models show a consensus with mid level height falls continuing Sunday afternoon through Sunday night. This will be ahead of an approaching strong shortwave from eastern part of the Great Lakes through SE Canada. The height falls appear to occur more rapidly compared to the previous night. The models indicate a return of positive vorticity advection Sunday afternoon into early Sunday evening. At the surface, a cold front will be approaching from the west, eventually moving Sunday afternoon and then moving west to east across the region Sunday afternoon into Sunday evening. The cold front passes southeast of Long Island late Sunday night. The models show 0-6 km bulk shear increases to near 40-50 kt and potentially above 50 kt as well. This combined with surface instability as conveyed by CAPE values between 2000 and 4000 J/kg across the region near NYC and locations north and west. Less CAPE to the east with more marine influence. There will be potential for strong to severe thunderstorms with damaging winds and large hail possible. Primary threat would be damaging winds. The forcing further is evident from the local region being relatively closer to the right rear quad of an upper level jet streak from SE to NE from New England into the Canadian Maritimes. This will provide for greater divergence aloft. CAMs show ongoing convection south of Long Island for early Sunday morning in the 6am to 10am timeframe. Then, shower activity sparse with mainly dry conditions thereafter until around 1-2 pm. From 1-2 pm, convection starts to redevelop north and west of the forecast and may start to move into parts of the Lower Hudson Valley. Between 2 and 5pm, the convection develops and solidifies into a squall line as it moves southeast farther into the local region, reaching through Southern CT, northeast NJ, Lower Hudson Valley, NYC into much of Long Island. Convection expected to linger across much of the area Sunday evening with much of the activity gradually shifting to more eastern locations. Eastern Long Island and Southeast CT could have some lingering showers and thunderstorms for the first half of the overnight. PWATs will remain a little above 2 inches Sunday into early Sunday evening for much of the region, again near 2.2 inches. Flooding will remain possible with thunderstorms. Also to note, some indication with max updraft helicity across parts of the region, mainly across interior. This signals a potential for rotation within thunderstorms. A brief tornado cannot be ruled out. Regarding temperatures, this will be quite dependent on cloud coverage. Still even with abundant cloud coverage, warm air advection expected to have much warmer high temperatures compared to the previous day. Forecast highs are well into the 80s for most locations with values more in the lower 80s along much of the coastline. Some parts of NYC and northeast NJ are forecast to reach the lower 90s. Max heat indices can be expected to be a few degrees above the actual temperature, keeping the forecast region below heat advisory criteria. The highest heat indices are forecast to be mainly between 90 and 95 with some 95 to 97 degree heat indices for mainly parts of northeast NJ. Overnight Sunday night into early Monday, dry conditions expected to eventually re-establish across the region from NW to SE. Forecast lows range from the upper 50s to mid 60s. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... The cold front will continue to push offshore Monday morning as the upper level trough over western and central portions of the Northeast treks southeast. This will be the focus for some lingering showers for eastern areas Monday morning and early afternoon. The high continues to build in for Tuesday and pushes offshore late in the day Tuesday into Tuesday night. Meanwhile, upper level ridging over the Great Lakes noses into the Northeast. This allows a warm front to lift north of the region sometime on Wednesday, and the associated cold front to start moving through sometime on Thursday, which then may stall somewhere near the area through the end of the week. With high pressure in place, conditions should be dry through Wednesday as the warm front lifts north too far west to bring any precipitation. Precipitation is expected with the approaching cold front and chances for showers and thunderstorms look to continue through the first half of next weekend. As for temperatures, they are expected to be seasonable through Wednesday. With upper level riding nosing in on Thursday, warmer conditions are forecast, with highs in the upper 80s to lower 90s away from the coast. Similar readings are expected through Saturday. Humidity levels will also be on the rise. Prior to Wednesday night, dew points will generally be in the 50s to around 60. From Wednesday night onward, dew points rise into the 60s to around 70. && .AVIATION /03Z SUNDAY THROUGH THURSDAY/...
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A warm front will continue to push NE through the terminals overnight. A pre-frontal trough approaches and settles nearby on Sunday, followed by a cold front Sunday evening. Most terminals lower to IFR tonight with the exception of most of the city terminals. -Shra overnight, then still a chance of a few showers Sunday morning through early afternoon, but will leave it out for now. Better chance of showers and thunderstorms with a convective line somewhere between 21z-02z, depending on location. Improving back to VFR otherwise during Sunday morning with VFR prevailing outside of any showers/thunderstorms. S-SW winds 10-15 kt with winds diminishing a little overnight. Winds are expected to become more SW Sunday morning, increasing back to 10- 15 kt. Occasional gusts around 20kt in the afternoon. Much stronger gusts possible if afternoon/evening thunderstorms materialize ...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty... KTEB and KEWR possibly lowers to IFR for a few hours late tonight. IFR start/end timing may be off by 1-2 hours for KLGA. End timing of IFR for KJFK may be off by 1-2 hours. Occasional or frequent gusts around 20kt possible Sunday afternoon. Much stronger gusts possible if afternoon/evening thunderstorms materialize. OUTLOOK FOR 00Z MONDAY THROUGH THURSDAY... Sunday evening: Sub-vfr in TSRA potential early on, then VFR returns by midnight. Monday through Wednesday: VFR. Thursday: Mainly VFR, with possible sub VFR later in the day and at night in possible SHRA or TSRA. 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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SCA on the non-ocean has been cancelled. The SCA remains on South Shore Bays and ocean through Sunday early evening with other waters staying mainly below SCA criteria. The ocean has SCA remaining through all of Sunday evening. Sub-SCA conditions expected Sunday overnight into early Monday. In terms of specially seas, just the ocean meets the SCA criteria through Sunday evening with other waters staying well below SCA thresholds for seas. Any SCAs for non- ocean waters are due to gusty winds near 25 kt. Winds and waves are expected to remain below SCA criteria from Monday through Friday. However, late day winds in the NY Bight area just E of Sandy Hook could gust close to 25 kt both Wed through Fri afternoons.
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&& .HYDROLOGY...
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No hydrologic issues anticipated into Sunday morning. Minor flooding more probable Sunday afternoon and evening with thunderstorms. Localized flash flooding cannot be ruled out. Total rainfall amounts through Sunday evening between a half to 1 inch, with locally higher amounts possible. Locally heavy rainfall may be possible Thu night into Fri with a passing frontal system.
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&& .TIDES/COASTAL FLOODING... The rip current risk is high this afternoon and evening with strengthening SE winds and building seas. The high risk continues into Sunday with swells of 5-6 ft and 7 second period. The high risk continues into Monday morning, but it looks like most beaches will transition to moderate from late morning onward. && .OKX WATCHES/WARNINGS/ADVISORIES...
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CT...None. NY...High Risk for Rip Currents through Sunday evening for NYZ075-080- 081-178-179. NJ...None. MARINE...Small Craft Advisory until 8 PM EDT Sunday for ANZ345. Small Craft Advisory until midnight EDT Sunday night for ANZ350-353-355.
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&& $$ SYNOPSIS...JM/JP NEAR TERM...DS SHORT TERM...JM LONG TERM...JP AVIATION...JC MARINE...JM/JP HYDROLOGY...JM/JP TIDES/COASTAL FLOODING...