958 FXUS62 KCHS 290247 AFDCHS Area Forecast Discussion National Weather Service Charleston SC 1047 PM EDT Sun Jun 28 2026 .WHAT HAS CHANGED... All sections have been updated for ongoing trends this evening. && .KEY MESSAGES... - 1) Hot and humid conditions will continue into Monday and another Heat Advisory may be required. - 2) High temperatures will be slightly above normal on Tuesday, then gradually rising through the holiday weekend. Heat Advisories could be required through the holiday weekend across portions of the forecast area. && .DISCUSSION... KEY MESSAGE 1: Hot and humid conditions will continue into Monday and another Heat Advisory may be required. Tonight: Overnight lows will be very mild providing little relief from the heat, only dropping into the mid to upper 70s. These values will challenge the record high minimums at the local climate sites, see the Climate Section for more details. Monday: The ridging aloft will persist into Monday, while the surface high pressure shifts to the south and weak low pressure develops along a stalled front off the southeastern coastline in the vicinity of the Outer Banks, NC. Another hot day is forecast, with temperatures reaching into the mid/upper 90s. These temperatures combined with dewpoints in the 70s will yield heat index values in the 103-110 range. Another Heat Advisory for portions of the forecast area, generally along and east of I-95, is possible. A complicating factor in regards to a potential Heat Advisory is with the stalled front and weak low pressure off the NC coast. With these features in the vicinity of the local forecast area an increase in afternoon convection is forecast, with PoPs in the 30-40% range. These showers/thunderstorms could disrupt peak heating - yielding heat index values shy of Heat Advisory criteria. At this juncture a Heat Advisory for Monday will not be issued and the need for a Heat Advisory will be reassessed with future forecast updates. While widespread severe weather is not anticipated, strong to marginally severe storms are possible, especially along boundary interactions. KEY MESSAGE 2: High temperatures will be slightly above normal on Tuesday, then gradually rising through the holiday weekend. Heat Advisories could be required through the holiday weekend across portions of the forecast 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 story 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. As for the convective potential, the pattern will only support chance POPs along our GA coast on Tuesday, then dry conditions Wednesday and Thursday, followed by slight chance POPs for portions of our area Friday into the holiday weekend. Even though POPs are not very high, any convection that forms this time of year, especially with these temperatures, will have the potential to be strong to borderline severe, along with having locally heavy rainfall. && .AVIATION /00Z MONDAY THROUGH FRIDAY/... VFR conditions should prevail at CHS/JZI/SAV terminals tonight through late morning Monday. However, a few showers could impact CHS/JZI terminals temporarily through 04-05Z Monday. Scattered showers/thunderstorms are also forecast Monday afternoon along/ahead of a front entering the region. PROB30 -TSRA groups have been added at CHS/JZI between 18-21Z Monday and at SAV between 19-23Z as a result. North/northeast winds around 10 kt are likely post fropa mid-late afternoon. Extended Aviation Outlook: Brief flight restrictions are possible due to showers and thunderstorms Monday afternoon and maybe Tuesday afternoon. && .MARINE... This Evening and Overnight: Southerly winds will continue to surge into the 15-20 kt range this evening. Overnight, southwest flow will remain somewhat elevated through the early morning hours. Seas are expected to be mostly 3-4 feet across most of the waters. Also of note, thunderstorms could develop/persist across coastal waters for the next few hours with gusty winds and lightning. The largest thunderstorm coverage will remain possible across the SC waters. Extended Marine: Expect weak winds on Monday as a front approaches from the north. The front will move south through our area Monday night, causing winds to shift to the NE by Tuesday morning. Then, the synoptic pattern will generally support winds from the NE or E through Thursday. Seas should stay 4 ft or less. No Small Craft Advisories are expected. && .CLIMATE... Record High Temperatures: June 29: KCHS: 99/1998 KSAV: 101/1959 July 3: KCHS: 98/2019 July 4: KCHS: 98/2023 KSAV: 99/1997 Record High Minimum Temperatures: June 29: KCHS: 79/1977 KSAV: 80/1885 July 3: KCHS: 78/2016 July 4: KCHS: 79/2016 KSAV: 79/1931 && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. MARINE...None. && $$