555 FXUS62 KCHS 292159 AFDCHS Area Forecast Discussion National Weather Service Charleston SC 559 PM EDT Mon Jun 29 2026 .WHAT HAS CHANGED... Key Message 1 has been replaced with strong thunderstorm potential into early evening hours. && .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 /21Z MONDAY THROUGH SATURDAY/... Prevailing VFR through the 18Z TAF period at KCHS/KJZI/KSAV. Winds at KCHS/KJZI initially out of the NW around 18Z will shift to the S/SE as the afternoon sea breeze works its way inland over the next hour or so. KSAV has the best chance of seeing afternoon showers/thunderstorms today, with a TEMPO group in place from 18 to 21Z. Once convection wanes this evening conditions overnight should remain precipitation free, with winds shifting back to the NE in the early morning hours. Extended Aviation Outlook: Brief flight restrictions are possible with isolated showers and thunderstorms Tuesday afternoon. && .MARINE... Rest of This Afternoon and Tonight: SE winds this afternoon gusting to around 10 to 15 knots will shift to the NE, remaining elevated. 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: June 29: KCHS: 99/1998 KSAV: 101/1959 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. && $$