Area Forecast Discussion
Issued by NWS Upton, NY

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103 FXUS61 KOKX 130006 AFDOKX Area Forecast Discussion National Weather Service New York NY 806 PM EDT Sat Jul 12 2025 .SYNOPSIS... High pressure remains along the New England coast into Sunday morning, then drifts east through Monday as a cold front moves into the region late Monday. The frontal boundary likely remains just offshore through mid week. Another frontal system may then impact the area towards the end of the week. && .NEAR TERM /THROUGH SUNDAY/... Surface high pressure remains along the New England coast tonight with a light flow across the region, and a warm and humid airmass remaining in place. Any convection across the Lower Hudson Valley will be weakening and dissipating early this evening with the loss of daytime heating. Any storms that do develop will be slow moving, and have the potential to produce briefly heavy rainfall. With the airmass in place, and a light southerly flow, low clouds are expected to develop along and offshore of the coast, and drift inland late tonight into Sunday morning. && .SHORT TERM /SUNDAY NIGHT THROUGH MONDAY/... Any low clouds and possibly fog will dissipate Sunday morning as low level mixing increases. The surface high off the New England coast drifts east late Sunday into Monday as the upper ridge axis moves offshore and heights gradually fall with the approach of an upper trough. Much of the energy with the trough will be passing to the north during Monday, and the trough weakens. A weak, and weakening cold front moves into the region either late Monday or Monday evening. And a warm and humid airmass remains through Monday, becoming unstable late morning into the afternoon with CAPE increasing to over 1000 J/kg. Precipitable water values will be around 2 inches Monday. With the weakening front, and little forcing convection will be more scattered, and opted for areal coverage wording. There will once again be the potential for any of the storms to produce briefly heavy rainfall, however the steering flow does increase Monday, and storms are expected to be moving southeast 20 to 25 mph. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... ***Key Points*** *While still some uncertainty, there is at least potential for a heat wave Tuesday through Friday for many areas with Max Heat Index values each day between 95 and 100 (Heat Advisory criteria). *Relatively active pattern with chances for several days of afternoon showers and thunderstorms. A cold front will just be passing through at the start of the long term period. This boundary will likely stall just offshore and linger for several days. A frontal system may then impact the area later in the week. Aloft, the pattern stays the same through the period. Although we are under some high heights, we are somewhat on the eastern end of a broad upper level trough centered over central Canada and few shortwaves likely pass through. With strong Bermuda high in place, a S/SW flow will allow plenty of moisture to be sent our way. This combined with above normal high temperatures brings some potential for a heat wave. NBM dewpoints are likely too high but even after manually lowering afternoon dewpoints when mixing is expected still seeing some 95-100 heat index values. However, there still is uncertainty especially given the potential for convection and slight inconsistencies in a late week frontal system among the guidance. Too early to talk specifics when it comes to severe or flooding concerns with the aforementioned convection. These details will be ironed over the next few days. There is plenty of moisture around with pwats 1.75-2.00+ for much of the period so any convection that does develop will likely be able to produce heavy downpours. As for severe, while we are pretty unstable, shear looks weak through much of the period. && .AVIATION /00Z SUNDAY THROUGH THURSDAY/...
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Weak high pressure remains in place offshore through Sunday. Mostly MVFR tonight. Some IFR mainly east of the city terminals. For Sunday, conds improve to VFR for most by noon. All but KGON likely eventually improve to VFR. SE winds under 10kt, becoming light and variable or a light E flow overnight. SE winds for Sunday at around 10kt. ...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty... Moderate confidence in conds lowering to at least MVFR for all terminals, however lower confidence in IFR chances and timing. For KJFK, IFR might not occur at all, or prevail for a few hours overnight. For KLGA/KEWR/KTEB, tempo IFR cigs possible for a few hours after midnight. If IFR occurs at any of these 3 terminals, chances are that it won`t prevail for more than a few hours. .OUTLOOK FOR 00Z MONDAY THROUGH THURSDAY... Sunday night: Mostly MVFR, but IFR possible east of the city terminals. Monday: MVFR or lower in the afternoon and early evening with showers and thunderstorms likely. Tuesday-Thursday: Mainly VFR. Showers or thunderstorm possible in the afternoon and evening. Detailed information, including hourly TAF wind component forecasts, can be found at: https:/www.weather.gov/zny/n90
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&& .MARINE... With a weak pressure gradient, winds and waves likely remain below Small Craft Advisory criteria tonight through next week. However, a relatively active pattern is expected next week with chances of afternoon showers and thunderstorms for several days. Winds and waves will be higher in any storms. && .HYDROLOGY...
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Isolated thunderstorms across the Lower Hudson Valley Sunday afternoon have the potential of producing localized heavy rainfall as the storms will be slow moving. And any potential flooding will also be localized. For Monday, there is a chance of minor flooding with heavy rainfall potential across a larger area as a cold front approaches during the day. However, any flooding will be localized. At this time there are no hydrologic concerns Monday night through the week.
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&& .TIDES/COASTAL FLOODING...
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The rip current risk on Sunday is moderate with an onshore flow near 10 kt, a 3-4 ft swell from the southeast at a 7 to 8 sec, and an added long period onshore swell.
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&& .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...High Risk for Rip Currents until 9 PM EDT this evening for NYZ075- 080-081-178-179. NJ...Air Quality Alert until 11 PM EDT this evening for NJZ002-004- 006-103>108. MARINE...None. && $$ AVIATION...JC