678 FXUS61 KOKX 291413 AFDOKX Area Forecast Discussion National Weather Service New York NY 1013 AM EDT Mon Jun 29 2026 .WHAT HAS CHANGED... No significant changes to the forecast. && .KEY MESSAGES... 1) Dangerous heat likely Wed to Fri, potentially continuing into Saturday. 2) Low potential for aft/eve thunderstorms on Tuesday, with potential increasing for mid to late week. && .DISCUSSION... .KEY MESSAGE 1... Heights start to rise aloft today as a strong upper level ridge begins to build in from the west. While some differences are still seen in the latest guidance in terms of amplification of this ridge, the general consensus of peaking between 592-594dam would be over the 90th percentile of observed 500mb heights for the OKX Sounding. At the surface, high pressure strengthens over the area through Tuesday and then shifts just offshore, basically remaining in control through the weekend. With this pattern in place, and a modified subtropical airmass, there is potential for a prolonged period of dangerous heat mid to late week. There have been no changes to the Extreme Heat Watch since it was issued on Sunday. A few things that still need to be ironed out, with one of the more important factors being dewpoints as is typical this far out. Given ambient temperatures in most inland areas are expected to already be near 100, forecast dewpoints will likely have more impact on heat headlines (Warning vs Advisory) for coastal areas like southeast CT and Long Island. Large spread in dewpoints are seen in the latest NBM with upwards of a 10-12 degree difference between the 10th and 90th and a 5-7 degree difference between the 25th and 75th. The LREF seems more reasonable with a lower spread, closer to 3 to 5 degree difference (between 25th and 75th percentile), with the spread being between the upper 60s and lower 70s. Did lower forecast dewpoints slightly each afternoon to reflect this uncertainty. Even with this, still seeing forecast Heat Index values between 105 and 110 for most. This set up will also limit overnight relief with lows potentially as high as the upper 70s to lower 80s for most. This could be a dangerous situation especially for sensitive groups. .KEY MESSAGE 2... Given our placement on the northern periphery of the upper level ridge, we are set up for potential convection/MCSs rounding the base of the ridge. While this is common in this pattern, there is usually a lot of uncertainty in timing, placement and strength of this activity. This is being seen currently with large spread in the latest guidance. However, guidance is currently hinting at activity Tuesday and Wednesday. Most notably the 00z 6/29 HRRR, FV3 and ARW showing a decaying MCS moving in from the northwest Tuesday afternoon. The SPC has kept the marginal severe risk northwest of our area. If any activity is approaching, it will likely be moving into an unfavorable environment with very little instability with distinct 600-800mb capping. Additional thunderstorm activity is possible on Wednesday, with the SPC expanding the marginal risk through the Lower Hudson Valley. There is a bit more uncertainty in the guidance for this time frame with difference in strength/existence of a shortwave moving through and its ability to weaken the ridge. This would be a high instability, weak shear situation with uncertainty in a trigger. This will have to be monitored by subsequent shifts. && .AVIATION /14Z MONDAY THROUGH FRIDAY/... High pressure in control with VFR through the TAF period. Chance of MVFR or lower at the eastern terminals late tonight. Winds are expected to remain at or under 10 kts today. S-SW winds do pick up Tuesday to near 10-15 kt by the early afternoon. NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty... No unscheduled amendments expected. .OUTLOOK FOR 12Z TUESDAY THROUGH FRIDAY... .Tuesday: Mainly VFR, but chances for IFR/LIFR in fog/stratus east of NYC terminals, more likely at KGON for early morning. Also, brief localized MVFR or lower possible in late day into nighttime showers or thunderstorms. S-SW wind gusts 15-20 kt mainly along the coast, afternoon into night. .Wednesday: Mainly VFR, but brief localized MVFR or lower possible in late day into nighttime showers or thunderstorms. SW wind gusts 15-20 kt mainly along the coast, afternoon into evening. .Thursday: VFR. .Friday: Mainly VFR, but chances for MVFR or lower with chances of showers and thunderstorms, especially towards the evening. Some SW- NW wind gusts 15-20 kt are possible. Detailed information, including hourly TAF wind component forecasts, can be found at: https:/www.weather.gov/zny/n90 && .MARINE... A Marine Dense Fog Advisory was issued for the eastern Long Island Sound, Peconic and Gardiners Bays and the ocean waters from Moriches Inlet to Montauk out 20 NM. The dense fog is expected to dissipate by mid morning. Mainly sub-Small Craft Advisory criteria expected through the weekend. There will just likely be a brief period Tuesday afternoon and then again Wednesday into Wednesday night when a S/SW flow will likely gust up to 25+ kt. During the Wednesday/Wednesday night period the ocean seas will also likely reach 5 to 6 ft. Rip Currents: No changes to the rip current forecast. Light winds and a 1-2 ft swell will lead to a low risk of rip activity today. A S/SW flow increases on Tuesday and Wednesday and will raise the risk to moderate, potentially high, with the developing S/SW wind wave. && .CLIMATE... Record High Temperatures: July 1: KEWR: 100/1963 KBDR: 95/1963 KNYC: 100/1901 KLGA: 97/2018 KJFK: 102/1963 KISP: 96/1964 July 2: KEWR: 102/1966 KBDR: 100/1966 KNYC: 100/1966 KLGA: 101/1966 KJFK: 101/1966 KISP: 99/1966 July 3: KEWR: 105/1966 KBDR: 99/1966 KNYC: 103/1966 KLGA: 107/1966 KJFK: 104/1966 KISP: 104/1966 Record High Minimum Temperatures: July 1: KEWR: 77/2018 KBDR: 73/2013 KNYC: 79/2018 KLGA: 79/2018 KJFK: 75/1968 KISP: 73/2025 July 2: KEWR: 79/2022 KBDR: 73/2022 KNYC: 82/1901 KLGA: 78/2002 KJFK: 74/2018 KISP: 74/2014 July 3: KEWR: 82/2002 KBDR: 75/2002 KNYC: 82/2002 KLGA: 81/1966 KJFK: 78/2002 KISP: 76/2018 July 4: KEWR: 81/2002 KBDR: 80/2002 KNYC: 81/2002 KLGA: 82/1999 KJFK: 80/2002 KISP: 76/2002 && .OKX WATCHES/WARNINGS/ADVISORIES... CT...Extreme Heat Watch from Wednesday afternoon through Friday evening for CTZ005>012. NY...Extreme Heat Watch from Wednesday afternoon through Friday evening for NYZ067>075-078>081-176>179. Air Quality Alert until 11 PM EDT this evening for NYZ069>075- 176-178. NJ...Extreme Heat Watch from Wednesday afternoon through Friday evening for NJZ002-004-006-103>108. Air Quality Alert until 11 PM EDT this evening for NJZ002-004- 006-103>108. MARINE...None. && $$ DISCUSSION...JT/NV AVIATION...DBR MARINE...JT/NV