


Area Forecast Discussion
Issued by NWS Upton, NY
Issued by NWS Upton, NY
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470 FXUS61 KOKX 021822 AFDOKX Area Forecast Discussion National Weather Service New York NY 222 PM EDT Tue Sep 2 2025 .SYNOPSIS... High pressure continues to shift offshore and weaken tonight. A series of fronts will moves through the region Thursday night through Sunday. High pressure builds in from the west Sunday and lingers into early next week. && .NEAR TERM /THROUGH TONIGHT/... As high pressure shifts farther offshore and weakens tonight, a very light return flow likely sets up. The big forecast challenge tonight is if low stratus/fog develops and if so how that will affect temperatures. As always the NAM is the most aggressive and covers the whole area while other guidance is dry. Leaning away from the NAM for now given the weaker return flow signal. Some guidance even has winds flipping back to the N or NE for a short period tonight given the very weak pressure gradient. However, agree with some stratus creeping into Long Island and eastern CT like the MET MOS guidance has. Because of this, bumped sky cover up across Long Island for tonight and also bumped temps up a few degrees in the spots that were lower due to expected radiational cooling. Locations across the interior will likely be able to get lower tonight, upper 40s to low 50s. && .SHORT TERM /WEDNESDAY THROUGH FRIDAY/... The area remains under troughing aloft through the short term, with the first of a few shortwaves swinging through early Friday. At the surface an associated cold front will move through early Friday, draping down from low pressure centered over Ontario. Ahead of the aforementioned cold front, dry and mostly sunny conditions are expected Wednesday and Thursday. As the front passes through however, showers and thunderstorms are possible. The most likely timing for this will be late Thursday night into early Friday morning. Confidence is thunder is very low at this time given the time of day and weak CAPE profile. Held on to slight chance for now. While there could be some localized downpours, rainfall rates will likely not be has high as we have seen with past events this summer. There does not appear to be any connection with tropical moisture offshore and pwats look to peak around 1.5-1.7 inches. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... The long term period starts with the region under the SE peripheral influence of an anomalously deep (3-4 std) closed upper low across Ontario into the upper Great lakes, and it associated longwave trough. The trough will slowly lift NE into Canada through the weekend with a transition to a zonal upper flow to start the week, and then heading into midweek western Atlantic ridging builds up the east coast ahead of the remnant upper low from Lorena deepening over the Central US. At the surface, an associated cold front approaches the region on Saturday, crossing Sat evening, with a secondary cold frontal passage later Sunday. Slightly above seasonable temps on Saturday with S/SW flow ahead of approaching cold front. The deep southerly flow between offshore ridging and troughing to the NW will allow a bit of southern moisture to work into the area ahead of front, developing a high shear-low CAPE environment. Low predictability this far out on timing of shortwave energy into the area, but potential for some thunderstorm activity along the front/pre-frontal trough Sat aft/eve, although early indication that most activity with the front could be post-frontal and more-so to the NW of the region with best forcing displaced well NW of the region. The NW displacement of the trough will make for a slow progress of the cold front through the region Sat Night into Sunday morning, likely not cleanly pressing through until Sun aft with trough axis passage and secondary cold front. This could set off a few showers on Sunday as well. Temps falling to near or slightly below seasonable on Sunday. In the wake of secondary passage, moderating Canadian surface high pressure builds in from the west early next week, bringing slightly below seasonable temps and dry conditions. No significant changes for the long term, so the NBM was closely followed. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... High pressure remains over the region through the TAF period. SE winds around 10 kt will become light and variable overnight. Prevailing VFR conditions through Wednesday. There is a chance of low stratus and patchy fog to develop tonight with an onshore flow, but confidence remains low. ...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty... Low chance of low stratus and patchy fog tonight and into early Wednesday morning. .OUTLOOK FOR 18Z WEDNESDAY THROUGH SUNDAY... Wednesday: Any morning MVFR/IFR conditions with low stratus become VFR. Thursday: VFR during the day with S gusts 20-25kt in the afternoon. SHRA and possible MVFR at night. Friday: SHRA/MVFR possible mainly in the morning. S gusts 20-25kt. Saturday: Mainly VFR. Low chance of MVFR/shra. Sunday: VFR. Detailed information, including hourly TAF wind component forecasts, can be found at: https:/www.weather.gov/zny/n90 && .MARINE... Sub-Small Craft Advisory conditions are expected through early Thursday. There is then potential for some 25 knot gusts ahead of an approaching cold front Thursday night. There will then likely be a lull in the gusts until Friday afternoon where there is a more widespread chance of 25 knot gusts. Marginal SCA gusts possible and SCA ocean seas into likely Fri Night into Sat in S/SW flow ahead of approaching cold front. Winds will likely subside Sat aft into eve and then shift NW Sat Night, with seas falling below SCA. Sub-SCA conditions likely Sun (outside of 20 kt NW gusts in wake of secondary cold frontal passage Sun aft/eve) into Mon as high pressure builds into the waters. && .HYDROLOGY... At this time there are no hydrologic concerns through early next week. && .TIDES/COASTAL FLOODING... There is a moderate rip current risk today and Wednesday as ESE swells build to 3-4 ft at 8-9 seconds. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...JT/NV NEAR TERM...JT SHORT TERM...JT LONG TERM...NV AVIATION...20 MARINE...JT/NV HYDROLOGY...JT/NV TIDES/COASTAL FLOODING...