654 FXUS62 KCHS 292359 AFDCHS Area Forecast Discussion National Weather Service Charleston SC 759 PM EDT Mon Jun 29 2026 .WHAT HAS CHANGED... The Aviation Section has been updated for the 00Z TAF issuance. The Marine Section has been updated for ongoing trends. && .KEY MESSAGES... - 1) A few strong thunderstorms are possible into early evening across Southeast Georgia. - 2) High temperatures will be slightly above normal on Tuesday, then gradually rising through the holiday weekend. Heat Advisories could be needed during the holiday weekend across portions of our area. && .DISCUSSION... KEY Message 1: A few strong thunderstorms are possible into early evening across Southeast Georgia. A boundary along the eastern periphery of a synoptic high will continue to provide a forcing/focusing mechanism for late afternoon into early evening showers and thunderstorms, mainly across Southeast Georgia (well inland across Jenkins to Tattnall County and across Long/McIntosh counties near the Altamaha River). Latest mesoanalysis indicates ample instability with MLCAPE between 2500-3000 J/kg and PWATs near 2.0 inches across areas which have yet to experience precip activity. DCAPE around 1000 J/kg and low-lvl lapse rates between 7.5-8.0 C/km suggest thunderstorms capable of producing gusty winds, and perhaps an isolated instance of damaging wind gusts with strongest convection during the next few hours. However, the risk for a severe thunderstorm should trend lower heading toward sunset. After sunset, activity should noticeably weaken with diurnal heat loss and a lack of shear in place KEY MESSAGE 2: High temperatures will be slightly above normal on Tuesday, then gradually rising through the holiday weekend. Heat Advisories could be needed during the holiday weekend across portions of our area. Ridging aloft will remain the dominant synoptic feature this week, initially centered over the TN Valley on Tuesday. It will then shift eastward towards the East Coast by the end of the week and remain in place through the holiday weekend. The main forecast highlight will continue to be the temperatures. Wednesday will feature highs slightly above normal, with temperatures warming to above normal into the holiday weekend. High temperatures could again reach into the mid to upper 90s late week and into the holiday weekend, which combined with dewpoint values in the 70s will likely yield heat index values in the 100-110 range. Heat Advisories could be required for portions of the forecast area at the end of the week and into the holiday weekend. Generally a dry forecast has been maintained, with PoPs trending upwards towards a more typical summertime pattern in the later half of the holiday weekend. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... VFR conditions are expected to prevail at CHS/JZI/SAV terminals through 00Z Wednesday. Winds will become light from the northeast overnight, then become more directly east Tuesday morning and afternoon, possibly gusting upwards to 15-20 kt during peak heating hours. A few showers and/or thunderstorms could impact the SAV during the afternoon, but confidence remains too low to mention in the latest TAF issuance. Extended Aviation Outlook: VFR conditions are anticipated at CHS/JZI/SAV terminals through late week. && .MARINE... This Evening and Overnight: East/southeast winds around 10 kt or less this evening will shift to northeast and slightly surge to 10-15 kt overnight well behind a boundary/weak front departing south of local waters. Seas will generally range between 2-3 ft, possibly building a foot approaching daybreak (largest beyond 20 nm from the coast). Extended Marine: The synoptic pattern will generally support winds from the NE or E through Thursday. Then, they will clock around to the SW by Friday morning. Friday into the holiday weekend, winds will have a typical summertime pattern. This will consist of some backing during the day, with the highest winds along the land/sea interface with the formation of the sea breeze. Gusts could approach 20 kt, especially in Charleston Harbor as the sea breeze moves through. At night, expect winds to veer and possibly ease a few kt. Seas should stay 5 ft or less. No Small Craft Advisories are expected. && .CLIMATE... Record High Temperatures: July 4: KCHS: 98/2023 KSAV: 99/1997 Record High Minimum Temperatures: July 3: KCHS: 78/2016 July 4: KCHS: 79/2016 KSAV: 79/1931 && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. MARINE...None. && $$