208 FXUS61 KOKX 251938 AFDOKX Area Forecast Discussion National Weather Service New York NY 338 PM EDT Fri Jul 25 2025 .SYNOPSIS... High pressure slides east this morning. A cold front will move through the area late this afternoon and evening. High pressure briefly builds into the area tonight into Saturday. A weak frontal system moves across the area Saturday Night into Sunday. High pressure returns to the area for Monday into Tuesday. A cold front approaches from the west on Tuesday afternoon and moves offshore Tuesday evening. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... Key points... * Severe Thunderstorm Watch now in effect through 9pm * Heat headlines remain in effect. Heat indices of 100 to 105F for most of the area, with locally up to 108F. Northern stream shortwave slides from Ontario/Quebec towards northern New England this evening with a cold front across W NY pushing across the region this evening. The combination of temperatures well into the 90s, combined with dew points in the lower to middle 70s, will have widespread heat index values of 100-105F continuing into early evening for much of the area. Max temps will likely flirt with daily records through this afternoon. Heat alerts continue through 8pm. Numerous discrete tstms (isolated severe) already developing across NE PA, Central NY and central New England as convective temps in the lower to mid 90s are being met. Pre-frontal trough across Central NY/PA and outflow boundaries from ongoing tstm activity. moving into a moderate to highly unstable airmass with marginal deep layer shear, along with approaching weak shortwave/vort axis, should allow for groups of these storms to cluster and developing into a few bowing line segments moving across the area. Severe thunderstorms watch in effect through 9pm to address this threat. Primary threat will be damaging wind gusts from wet downbursts (possibly a few bowing segments) in primarily a uni-directional WNW flow aloft, high PWAT environment with some mid- level dry air entrainment potential, and steep low-level lapse rates. 60 mph winds gusts likely, with isolated gusts to 70+ mph possible where mature bowing segment develops. Isolated large hail possible with right moving supercells in slightly veered low levels with undirectional shear aloft. In addition, any storms will be capable of producing heavy rainfall. 0.4"/5min rate noted with one of the cells as it moved over a mesonet, presenting a localized flash flood threat with any storms repeating over a location. See hydrology section for low and localized flash flood threat in a 2+ STD PWAT environment ( 2 1/4"-2 1/2" PWATs). Cold front expected to push SE of the region by 7-9pm this evening as northern stream shortwave slides through northern New England, with a relatively cooler and drier airmass filtering in its wake as high pressure builds down from the north. Low tonight into the lower to mid 70s along the coast and upper 60s interior with Tds gradually falling into the mid to upper 60s. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/... Region remain on northeast periphery of strong southern upper ridge through the weekend, with subtle ridging nosing in on Saturday giving way to a shearing central plain short wave Sat Night into Sunday. At the surface, this evening`s cold front slides well SE of the region by Saturday morning, with surface high pressure building in from the north and centering to the E of the region by Sat Night. Dry conditions expected on Saturday, with noticeably drier and cooler airmass advecting in on gusty N/NE flow Saturday AM, and a veil of high clouds in upper flow. Temps will still run slight above seasonable with highs in the mid to upper 80s, and heat indices similar. Models in general agreement with a shearing Central plains shortwave approaching Sat Night and moving across the area Sunday. At the surface, this will have a warm front approaching the area Sat Night but likely not cleanly moving through the area till Sun aft with a trailing trough crossing the region in the afternoon or evening. Models have had a hard time locking in on the specific of this event for a few days, with likely difficulty in resolving the synoptic development tied to mesoscale convective activity. Seems to be some general agreement in a weak wave of low pressure tracking across the region Sun morning into afternoon, which would be a focus for more widespread shower and thunderstorms activity and a low flash flood and severe risk in a high shear and marginally unstable airmass. Latest guidance has trended this wave north of the region, which would limit severe/flash flood potential in the morning, and keep it low and isolated in the aft/eve with warm front/trough passage. This will be refined through the weekend as the convectively modified shortwave gets better sampled it resolved by high res CAMs. Otherwise near seasonable temps for Saturday Night with increasing humidity levels as return flow develops. Warm and muggy for Sunday, but temps may remain below seasonable with clouds and shra/tsra activity. && .LONG TERM /MONDAY THROUGH FRIDAY/... No major changes were made to the long term with this update. Key Points: *High heat and humidity will return early next week, potentially lingering into Wednesday. The peak of the heat currently looks to occur on Tuesday with max heat index values 100 to around 105F. *A few showers and thunderstorms are possible Tuesday afternoon and evening with a weak cold front. The threat for showers and thunderstorms continues Wednesday, potentially lingering into Thursday as a stronger cold front moves into the area. *Temperatures trend down to end the week with potential of below normal temperatures. Humidity levels also should be much lower than the first half of the week. Good model agreement continues with a large upper ridge over much of the central and southern CONUS dominating the weather pattern early next week. The ridge builds towards the area Monday and Tuesday then slowly gets pushed southward as a deep upper trough digs down from southeast Canada to end the week. A series of shortwaves will move across the northeast as the ridge weakens late Tuesday into the mid week period. 850 mb temperatures nearing 18-21C early next week, peaking on Tuesday, will result in max temperatures in the low to mid 90s (upper 80s at the coast). Dew points will likely increase to the low and mid 70s by Tuesday resulting in heat indices potentially as high as the low 100s (upper 90s coastal areas). Heat headlines are likely to be needed Monday and Tuesday. There is a bit more uncertainty with the extent of the heat on Wednesday due to timing of the aforementioned second cold front. This front passage may not occur until Wednesday night or Thursday, which would potentially bring another day of heat and humidity on Wednesday. The air mass then cools significantly Thursday into Friday with the cold front pushing to our south and east. The latest NBM deterministic indicates highs in the upper 70s and lower 80s with dew points in the 50s by Friday. A shower or thunderstorm is possible Tuesday afternoon/evening, but the chances are a bit higher on Wednesday with the stronger cold front. Model soundings indicate 500-1000J/kg of MUCAPE though shear is weak (~20kts) on Tuesday. Shear increases on Wednesday and modest instability may be present. CSU-MLP machine learning output is highlighting a 15-30% chance of severe thunderstorms, mainly from NYC north and west Tuesday. It also indicates a similar potential on Wednesday although it is shifted from NYC metro on south and west. These details will come into more focus over the next few days, but the trend in the last 24 hours is leaning towards Wednesday with the main cold front and more organized forcing for convection. && .AVIATION /20Z FRIDAY THROUGH WEDNESDAY/... A cold front passes through late this afternoon/evening, with high pressure briefly following for Saturday. VFR through much of the TAF period. MVFR or lower visibilities are likely as TSRA may impact the terminals until around 22-23z. Strong gusty winds are possible with any thunderstorm as storms could reach severe levels. Have kept TEMPO groups for TSRA and added enhanced wording for gusts for some sites given strong to severe cells currently being observed. Also given the slightly earlier start time have moved up the end time of TSRA. SW winds around 10 kt become NW behind the frontal passage in the late afternoon/evening. Winds then veer overnight into Saturday becoming SE by Saturday afternoon around 10 kt. Occasional gusts up to about 20 kt are possible during this afternoon outside of TSRA. ...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty... Occasional gusts up to 20 kt are possible this afternoon outside of thunderstorms. Severe thunderstorms are possible this afternoon/evening. Strong to damaging wind gusts are the biggest threat should a severe storm develop. Large hail looks like less of a threat. .OUTLOOK FOR 18Z SATURDAY THROUGH WEDNESDAY... Saturday: VFR. Saturday night - Sunday: Mainly VFR. MVFR or lower possible in any showers or thunderstorms. Monday: VFR. Tuesday - Wednesday: Mainly VFR with possible MVFR or lower in showers and thunderstorms each afternoon. Detailed information, including hourly TAF wind component forecasts, can be found at: https:/www.weather.gov/zny/n90 && .MARINE... Some occasional gusts to 25 kt are possible in a S flow on ocean waters and southern bays of LI this afternoon/evening ahead of a cold frontal passage. Scattered severe thunderstorms are likely late this afternoon and this evening ahead of a cold frontal passage this evening. A brief period of 20 kt gusts are possible in wake of cold frontal passage Friday night into Saturday morning. A relatively weak pressure gradient Monday through Wednesday will lead to conditions staying below SCA levels. && .HYDROLOGY... Primarily a minor urban and poor drainage flooding threat with thunderstorm activity this afternoon that could produce rainfall rates of 2+"/hr with PWATS as high as 2"-2 1/2", but will be overall progressive limiting duration over an one area. Based on these rainfall rates, there is a localized flash flood threat with any repetitive thunderstorm activity, particularly if the cold front orients in a more W to E fashion as indicated by some CAMs. A general 1/4 to 3/4" basin average, with a low and localized probability for 2-3" in 1 to 2 hrs with any training. Showers and thunderstorms associated with a frontal system could produce locally heavy downpours on Sunday that present a minor urban flooding threat, with localized flash flood threat appears low at this time. There are currently no hydrologic concerns next week. && .TIDES/COASTAL FLOODING... A moderate to locally high rip current risk is in effect through this evening with southerly wind waves building to 3 to 4 ft. A moderate rip current risk continues for Saturday, though surf heights lessen to 2-3ft and winds become east/southeasterly. && .CLIMATE... Daily record high temperatures maybe be tied or broken today July 25th. Here are the current records for the day... EWR 99/2016 BDR 93/2001 NYC 97/1999 LGA 97/1999 JFK 93/2010 ISP 94/1987 && .OKX WATCHES/WARNINGS/ADVISORIES... CT...Heat Advisory until 8 PM EDT this evening for CTZ005>011. Air Quality Alert until 11 PM EDT this evening for CTZ009>012. NY...Heat Advisory until 8 PM EDT this evening for NYZ067>075- 078>080-176>179. Air Quality Alert until 11 PM EDT this evening for NYZ069>075- 078>081-176>179. NJ...Heat Advisory until 8 PM EDT this evening for NJZ002. Air Quality Alert until 11 PM EDT this evening for NJZ004-006- 103>108. Extreme Heat Warning until 8 PM EDT this evening for NJZ004- 006-103>108. MARINE...None. && $$ SYNOPSIS...DS/NV NEAR TERM...NV SHORT TERM...NV LONG TERM...DS AVIATION...JT MARINE...DS/NV HYDROLOGY...DS/NV TIDES/COASTAL FLOODING... CLIMATE...