It was a stifling hot Wednesday in the Lowcountry, with highs reaching the upper 90s and heat indices peaking between 113-116° in parts of the metro area. Another round of high heat is in store for Thursday, as temperatures once again return to the upper 90s. Dewpoints near the coast and behind the seabreeze should surge well into the mid-to-upper 70s once again, sending heat indices between 108-113° (with locally higher readings possible) in the Highway 17 corridor. This has prompted another Extreme Heat Warning for Charleston County as well as the southern portion of Berkeley County that includes Hanahan and Daniel Island. Elsewhere, a Heat Advisory will be in effect for heat indices around 108-110°. Model guidance still suggests a few showers and thunderstorms will fire off along and ahead of the seabreeze, which will help cool some of us off. Coastward storm motions moving against the inland-moving seabreeze could cause some back-building of thunderstorms with some locally heavy rain. The strongest storms could produce damaging wind gusts, and a warning or two can’t be totally ruled out as a result.

Dangerous heat and humidity continues across the Lowcountry as we get into the second half of the work week with fewer opportunities for relief from thunderstorms.

The heat wave continues Tuesday with another hot and humid day on tap, followed by a scattering of afternoon thunderstorms. We’ll start in the upper 70s inland to low 80s near the coast and downtown, warming to the mid-90s in the afternoon. Dewpoints in the mid-70s will drive heat indices toward 108-110°. Another Heat Advisory will be in effect for Charleston and Berkeley counties as a result. Further inland toward Dorchester, dewpoints should be ever so slightly low enough to stay out of Heat Advisory criteria, but it’s still going to be plenty hot.

From there, a few thunderstorms should fire along and ahead of the seabreeze. Storm motions should be a little more coastward, so keep an eye out at the beaches for possible thunderstorms. A stray severe storm is not out of the question, with damaging wind gusts and hail to the size of quarters possible.