Late-summer heat and humidity continues to build as temperatures look to return to the 90s for Thursday after a balmy start in the mid-70s. We should see a bit more in the way of afternoon showers and thunderstorms on the seabreeze with high pressure beginning to weaken, though not everyone will see rain, either. A few pockets of heavy rain will be possible with moderate instability and precipitable water values (generally the amount of water you could wring out of a column of air) a little over 2″.

There may be one more round of salt water flooding with Thursday evening’s high tide around 8:18 PM, but it’ll be on the minor side with water levels peaking in the 7-7.2′ range. Rain shouldn’t be an issue as the seabreeze will be well inland by that point, though. From here, we should see diminishing astronomical influences and less of a chance for coastal flooding, though there remains an outside shot on Friday coincident with the full moon.

Summer won’t loosen its grip just yet, especially as we head into Friday and Saturday as a front approaches the area, sending air temperatures back to the mid-90s and heat indices close to heat advisory territory.

Thursday looks to generally be a repeat of Wednesday (weather-wise, anyway). We’ll start the day in the mid-70s once again, warming to the low 90s in the afternoon. Mid-70s dewpoints will help drive the heat index into the upper 90s to around 100° — not quite August, but getting long in the tooth. The day should be primarily quiet with partly cloudy skies expected, though like we saw roll through Moncks Corner on Wednesday, a stray shower can’t be totally ruled out.

A front at the surface and a trough of low pressure aloft will keep things on the unsettled side heading into Friday and the weekend, with the potential for heavy rain especially Friday and Saturday.

Thursday’s weather setup will be similar to what we saw on Wednesday with scattered to numerous thunderstorms affecting some spots while the sun peeks out elsewhere. Temperatures will start in the low to mid-70s once again, warming to around 90° in the afternoon — just a smidge above normal for late August. The severe weather risk is low, but once again, a storm or two could produce gusty winds. There is also the risk for flooding given slow storm motions and potential training of rain across the same spots, so stay alert as you get out and about tomorrow.

The hot pattern we have been stuck in for the better part of a week and a half finally begins to break down starting Friday, helping to temper some of the extreme heat that we’ve experienced while also allowing for more showers and thunderstorms, particularly Friday and Saturday.

Another hot day lies ahead on Thursday, but we do have some changes coming that will turn conditions a little more unsettled, which in turn will start to take the edge off this heat some.

That being said, Thursday will mark the ninth consecutive day of heat headlines of some sort, whether it be a Heat Advisory or an Extreme Heat Warning, and it’s getting very difficult to find new ways to tell you it’s going to be hot. We start Thursday in the upper 70s to low 80s once again, with air temperatures in the afternoon peaking in the mid-90s. Heat indices will once again peak between 108-112° — not as bad as it has been, but still pretty gnarly — and that’s prompted the aforementioned heat advisory for Charleston and Berkeley counties. (Looks like we’ll fall short of heat advisory criteria in Dorchester County, but it will still be quite hot to the point where you’ll want to monitor for heat illness if outdoors for an extended period.) A few of us should see some isolated to scattered thunderstorms in the afternoon along and ahead of the seabreeze. There’s not much shear and storm motions will be slow, so heavy rain will continue to be a concern, and with plenty of instability available, storms could produce frequent lightning and gusty winds in downbursts. Be ready for conditions to change on a dime if out and about.

Dangerous heat will continue to be the main weather story as we head into Friday and the weekend, with an isolated to scattered afternoon thunderstorm the only real shot at bringing about any reprieve.

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.