


Area Forecast Discussion
Issued by NWS Upton, NY
Issued by NWS Upton, NY
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-- Discussion containing changed information from previous version are highlighted. --681 FXUS61 KOKX 011738 AFDOKX Area Forecast Discussion National Weather Service New York NY 138 PM EDT Tue Jul 1 2025 .SYNOPSIS... A cold front will approach later today and pivot through late tonight into Wednesday morning. Another cold front will approach on Thursday and move through Thursday evening, followed by high pressure on Independence Day and into the weekend. Another frontal system may impact the area early next week. && .NEAR TERM /THROUGH TONIGHT/... Except for SE CT/eastern Long Island, skies has cleared out as last night`s convection has pulled off to the east, with MLCAPE already 1000-1500 J/kg and forecast to increase to 1500-2500 J/kg this afternoon. A pre-frontal trough will set up from NYC north/west this afternoon as thickness ridging works into the area (H5-10 values up to 576 dm), a very moisture- laden air mass with PW 2.2 inches on the KOKX 12Z sounding. It will be very warm and humid, with high temps in the lower 90s in the urban corridor and heat index values in the mid/upper 90s in spots within this area. Elsewhere high temps will be in the upper 80s most elsewhere, and mid 80s along most south facing shorelines, with heat index values generally 90-95. There is some question as to when convective initiation will take place today. Attm most likely scenario appears to be numerous shower/tstms developing across central/southern NJ by 18Z and drifting up into parts of the NYC metro area and Long Island, while scattered activity develops to the north/west of NYC around that same time and exhibits some upscale growth to multi-cell clusters given effective bulk shear of about 25 kt as it propagates SE toward the NYC metro area later in the afternoon and early evening. SPC maintains a slight risk for NJ and a marginal risk for areas to the northeast, with the main threat damaging wind from water-loaded downdrafts. Marginal mid level lapse rates may limit the severe potential somewhat, hence the slight risk only for NJ. There could be another pulse of convection later in the evening/overnight, but it would likely be primarily non-severe as previous activity may have worked thing over a little and also getting away from the peak diurnal heating later at night with the arrival of the actual cold front. There is also a slight risk of excessive rainfall across much of the area. Training/repeating storms would be the culprit if flash flooding were to take place, but at this point leaning more towards a localized urban related risk due to high instantaneous rainfall rates. Kept PoP elevated all night long based on the newest data with things progressing a tad slower, with higher PoP east into the overnight. With the cold front more or less slowing late at night look for a damp and cloudy, muggy night with temperatures remaining primarily in the 70s, and dewpoints remaining elevated. && .SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/... Clouds remain into Wednesday morning as the front struggles to get further east. Western most location should begin to clear sooner than eastern sections. Chance showers remain for most of the morning across eastern most sections, primarily east of the metro. Toward mid day PoPs really trail off with only a slight chance of lingering showers across eastern most sections during the afternoon. Dew point readings will remain elevated and only lower slightly, mainly across NW sections later in the day. Temperatures overall will be a tad cooler with mainly middle 80s, with some lower 80s closer to the coast on a light W to SW wind. More of a sea breeze influence is anticipated further southeast and along the coast in the afternoon with a light synoptic gradient and the front more or less washing out nearby. Cannot totally rule out an isolate shower or storm in the afternoon as hinted by some CAMs, but have kept this out of the forecast wording for the time being. For Wednesday night clouds get further east and mainly offshore late with only a subtle drop in humidity was dewpoint remain primarily in the middle 60s across much of the area. Thus temperatures should only fall into the middle and upper 60s in most places, with lower 70s in the metro, with perhaps a little patchy fog in the outlying areas possible. && .LONG TERM /THURSDAY THROUGH MONDAY/... No significant changes were made to the extended forecast with only a few minor edits made to NBM guidance. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/...-- Changed Discussion --A cold front approaches from the west today and stalls over the area into Wednesday morning. VFR to start the afternoon. Scattered SHRA, with possible TSRA, develops into late aft and could lead to MVFR or IFR vsbys at times. Best window for TSRA generally btwn 19Z and 01Z Wed. SHRA persist into the overnight, and MVFR cigs likely prevail late tonight until daybreak or so, then improvement and return to VFR thru mid morning. Winds SW 10-15 kt this afternoon with gusts around 20 kt. Flow becomes lighter tonight, and speeds remain at or under 10 kt on Wed. ...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty... Start time of potential shra/tstm this afternoon could be off an hour or two. Timing of improvement Wed AM could be off by a few hours. Isolated shra/tsra possible late Wed afternoon. .OUTLOOK FOR 18Z WEDNESDAY THROUGH SUNDAY... Wednesday PM: Mainly VFR. Isolated SHRA/TSRA possible late aft. Thursday: Possible showers and thunderstorms with brief MVFR or lower possible day into early eve, higher chances north and west of NYC terminals. Friday-Sunday: VFR. Detailed information, including hourly TAF wind component forecasts, can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --&& .MARINE... As a cold front approaches, S flow will increase, with ocean seas building to 4-5 ft and perhaps a few gusts close to 25 kt mainly E of Fire Island Inlet this afternoon into tonight. SCA remains in effect there but has been cancelled to the west. Elsewhere, a few gusts close to 25 kt may occur on the eastern Sound/bays of Long Island later today into this evening. For Wednesday sub advisory conditions should return on the ocean with a W-SW wind and ocean seas mainly remaining at around 4 ft. Generally tranquil conditions Wednesday night through Saturday will result in sub-SCA on all waters. && .HYDROLOGY... There is a slight risk of rainfall for most of the area through tonight. With high PW in place instantaneous rain rates should be high, with to a localized risk of flash flooding in stronger thunderstorms. Repeating/training cells could lead to a higher risk, which is possible given deep layer SW flow with speeds getting over 30 kt in the mid levels. && .TIDES/COASTAL FLOODING... There is a high risk of rip currents today, and this could also be the case into Wednesday, with wave heights not coming down much, along with a lingering 9-second E swell component. && .OKX WATCHES/WARNINGS/ADVISORIES...-- Changed Discussion --CT...None. NY...High Risk for Rip Currents until 9 PM EDT this evening for NYZ075- 080-081-178-179. NJ...None. MARINE...Small Craft Advisory until 6 AM EDT Wednesday for ANZ350-353.-- End Changed Discussion --&& $$ SYNOPSIS...JE NEAR TERM...JE/BG SHORT TERM...JE LONG TERM... AVIATION...JC/DR MARINE...JE/BG HYDROLOGY...JE/BG TIDES/COASTAL FLOODING...