We’ll take the heat up a notch for Thursday as even hotter air temperatures in the upper 90s — perhaps approaching 100° in a few spots — combine with dewpoints in the mid-to-upper 70s to produce heat indices pushing 110-113°. This potential has prompted an Extreme Heat Warning for Charleston and tidal Berkeley counties (Daniel Island, Hanahan) from 11am-8pm. Elsewhere in Berkeley and Dorchester counties, a Heat Advisory will be in effect for the same time period. In these areas, heat indices should peak in the 108-110° range — still quite dangerous, but not nearly as intense as what folks will see closer to the coast, where the moisture-rich maritime air will make it that much harder for your body to cool down. If you must be outside during the advisory/warning period tomorrow, take frequent breaks in the shade with plenty of water.
There will be a risk for a few showers and thunderstorms in the afternoon as some energy ripples by aloft, riding around the periphery of a strong ridge of high pressure centered in the midsection of the continental US. If storms can get going, a stray strong storm or two won’t be out of the question given plenty of moisture to work with. However, don’t count on a thunderstorm to impart much, if any, relief from the extreme heat.
Showers and thunderstorms will remain in the forecast as we head into Friday and the weekend, with the best rain chances on Saturday as a slug of moisture moves ashore.
Like the past few days, we will be getting our storms out of the way during Thursday’s morning and early afternoon hours as storms developing over the Atlantic drift coastward. Expect a warm and muggy start in the mid-70s, warming to around 90° in the afternoon once the sun emerges from behind the clouds. Showers and thunderstorms will once again be capable of producing heavy rain, with a flood advisory or two not out of the question especially if storms begin to train. We may also see a waterspout or two as well; earlier today, a storm off Kiawah produced four waterspouts (none of which made it to shore, at least). Keep an eye out on the beaches or if you have some boating planned.
A brief interlude in midsummer humidity comes to a close as a stalled front that’s been hanging just south of the area lifts back northward on Friday. A stronger front approaches over the weekend, with deeper moisture and more widespread storms possible Sunday.
What looks to be a top-five-warmest July on record will close on a slightly cooler and drier note as high pressure nudges in from the north. Thursday starts in the mid-70s across the area, warming to the low-to-mid-90s in the afternoon with plenty of sunshine. As mentioned, the drier air will keep heat indices a little more in check, though they may still get close to 100° near the coast where the more humid maritime airmass resides. But with all that in mind, it’ll still feel better outside than it did at the start of the week.
A cold front that’s brought quite a bit of rain to North Carolina today will continue to sag southward Friday, stalling out around the area over the weekend and keeping our weather relatively unsettled as a result.
Heat and humidity continues for Friday and the weekend with high pressure aloft the main weather driver. Atlantic high pressure will continue to drive high dewpoints into the area, and that not only will drive heat indices well into the 100s, but it will keep us quite toasty at night, too. Expect lows in the upper 70s each day, perhaps not dropping below 80° closer to the coast and downtown.
High pressure rebuilding aloft will bring more sunshine — but more heat, too. We’ll start Thursday in the mid-70s inland to upper 70s near the coast. From there, plenty of sunshine will drive highs into the mid-90s. Dewpoints will be fairly juicy — generally in the mid-to-upper 70s — and this will drive heat indices well into the mid-100s. Closer to the coast as well as in downtown, dewpoints near 80° will help drive the heat index up toward 108° for at least a brief period. Heat Advisory criteria is a heat index 108°-112° for two hours or more, and we certainly could be close in the coastal corridor. Regardless, be sure you’re taking frequent breaks in the shade with plenty of water if you’re working outside.
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.
