Area Forecast Discussion
Issued by NWS Upton, NY

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168 FXUS61 KOKX 111444 AFDOKX Area Forecast Discussion National Weather Service New York NY 1044 AM EDT Fri Jul 11 2025 .SYNOPSIS... A weak cold frontal boundary will slowly push south of Long Island today into tonight. High pressure then builds in from the north and east going into this weekend. A warm front approaches early Sunday, followed by a cold front approaching Sunday night. High pressure eventually returns early next week, building in through the middle of next week. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... While fog has not been observed too much this morning within the forecast region, there have been reports of some light drizzle in different portions of the area. Any fog and drizzle expected to diminish later this morning when there is more warmth. A slow moving cold front boundary pushes farther south through today. The frontal boundary will also be weakening. Looking aloft, ridging is taking place as a shortwave and its associated jet streak move farther northeast of the region. There won`t be much steering flow. CAMs depicting some shower and thunderstorm activity along a daytime trough developing across the interior with some interaction with higher terrain. Convective initiation appears to be delayed in some of the CAMs until mid to late afternoon. The convection is expected to be isolated to scattered and restricted to mainly north and west of NYC where there will be higher CAPE. More sun is expected but extra clouds with convection and some easterly component to the flow will limit the high temperature potential. Used a blend of MAVs and NBM, ranging mainly within the 80s, highest across parts of the interior and NE NJ. Without much change in dewpoint, heat indices reach a few degrees higher than the actual temperature. However, they still max out in the lower 90s range, below advisory criterion. && .SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/... With the lack of synoptic forcing aloft tonight, would expect any shower or thunderstorm activity to rapidly diminish this evening with the loss of diurnal instability. Models are showing however some increase in shortwave activity late tonight into early Saturday morning with some increase in upper level winds. Might have a shower or thunderstorm across parts of the interior with otherwise a mainly dry night expected. Light southeast flow at the surface tonight as well as abundance of clouds will help mitigate radiational cooling. Lows forecast tonight will only be ranging mainly from upper 60s to lower 70s. Another round of late night into early morning fog is forecast, but kept more areas across the interior with coverage more patchy elsewhere. HRRR indicated this fog development offshore and moving into the area from the low level southeast flow. For the rest of this weekend, with daytime instability each day, potential for showers and thunderstorms, mainly north and west of NYC. Airmass remains very warm and humid but looks like heat indices still expected to remain below advisory thresholds. && .LONG TERM /MONDAY THROUGH THURSDAY/... A broad mid level trough centered over the Upper Great Lakes translates east into early next week, helping advance a frontal system toward and through the region, bringing increased chances for a more widespread rainfall, especially on Monday ahead of the cold front. Parameters appear at least marginally supportive of thunderstorm development, but steering flow appears progressive enough to mitigate significant flood concerns. Conditions dry behind the fropa into midweek as weak high pressure drifts in and NW flow aloft looks to lower the humidity. Temperatures through the period look to largely stay in the 80s most afternoons thru early week, with a gradual warm up then into mid next week. National blended guidance was followed for this update. && .AVIATION /15Z FRIDAY THROUGH TUESDAY/...
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A weak frontal boundary slowly shifts south of the terminals through tonight. Flight categories are improving as low cigs are gradually eroding late this morning. Most return to VFR by 16Z, but MVFR could linger at KISP and KGON into early afternoon. A shower or thunderstorm remains possible at KSWF late afternoon and early this evening. Conditions should start falling back to MVFR or IFR tonight, but timing and extent remain uncertain. Light NE or variable flow to start will gradually become SE into the afternoon. Wind speeds will remain under 10 kt. Winds become light and variable tonight. ...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty... MVFR may linger an hour longer late this morning. Low confidence with flight categories tonight. .OUTLOOK FOR 12Z SATURDAY THROUGH TUESDAY... Saturday-Sunday: Mainly VFR. A chance of showers and thunderstorms during the afternoon and early evening near and northwest of the NYC terminals. Monday: VFR. Showers and thunderstorms possible, mainly in the afternoon and evening. Tuesday: VFR. Showers or thunderstorm possible in the afternoon and evening, mainly NYC metro on N and W. Detailed information, including hourly TAF wind component forecasts, can be found at: https:/www.weather.gov/zny/n90
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&& .MARINE... Not much forcing and absence of a steep pressure gradient keeps conditions below SCA thresholds on all waters through this weekend. Light flow and low seas should then maintain sub Small Craft Advisory conditions on all coastal waters through early next week. && .HYDROLOGY... Any thunderstorm that develops could deliver a quick period of heavy rain and localized minor flooding through this weekend. PWATs forecast to increase to near 1.7 to 2 inches this weekend. Most locations expected to stay dry though. No significant hydro concerns in the long term. && .TIDES/COASTAL FLOODING... Rip current risk is low through Saturday along Atlantic facing ocean beaches with onshore flow 5-10 kt and a 3 ft swell from the southeast at a 7-8 sec period. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...JM NEAR TERM...JM SHORT TERM...JM LONG TERM...DR AVIATION...DR/DS MARINE...JM/DR HYDROLOGY...JM/DR TIDES/COASTAL FLOODING...