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.
Tuesday will be a lot like Monday was, it looks like, with lows in the mid-70s yielding to highs in the low 90s in the afternoon. With the persisting stationary front to our west and the afternoon seabreeze, we can expect generally scattered thunderstorms to develop once again in the afternoon. Not everyone will see a storm, but those that do could see heavy downpours and even some severe weather, with damaging wind gusts the main concern.
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.
Another extremely hot day is on tap for Tuesday as temperatures take what should be one last shot at the 100° mark before sanity begins a slow return to the forecast. We’ll start the day near 80° inland of the coast, and we’re almost assuredly not getting below 80° at the coast and in downtown Charleston. From there, temperatures will soar into the upper 90s to near 100°, with the best risk of reaching the 100° mark inland of Highway 17. And then there are the dewpoints running in the mid-to-upper 70s, which will propel heat indices well into the mid-110s for many of us, with a few readings getting uncomfortably close to 120° in more rural spots. For the first time in this heat wave, an Extreme Heat Warning is in effect for the entire Tri-County, including Dorchester; to this point, we’ve only seen those warnings come out for Berkeley and Charleston. Continue to heed precautions for extreme heat: air conditioning if at all possible, but frequent breaks in the shade with water if you must be outdoors.
There will be a slightly better chance of thunderstorms Tuesday afternoon than we saw on Monday, which will cool some of us off. The price for this, though, is an elevated risk for strong and potentially damaging wind gusts, excessive lightning, and very heavy — perhaps flooding — rain in a few spots. Instability will be running on the high end of what we usually see around these parts, so any storm that can take advantage could take off like a rocket. The good news is that without much shear, storms will generally pop, rain for a while, and then collapse.
Extreme Heat Warnings look to take a break on Sunday, but that is little solace with heat indices expected to continue to peak into the lower 110s in the afternoon, well into Heat Advisory criteria. Scattered showers and thunderstorms should develop again in the afternoon along the seabreeze, and a few of those could be on the strong side given plenty of instability once again. We’ll also see a risk for flooding, especially where storms train in the same areas, courtesy of a well-saturated atmosphere. Be ready for conditions to change quickly, particularly after 3-4 PM.
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.
It’s a very toasty start to the school year for Charleston County on Tuesday as this week’s heat wave will begin in earnest as high pressure aloft takes hold. We’ll start the day on a very mild note, with lows in the mid-to-upper 70s warming to the mid-90s in the afternoon. Dewpoints will run in the low-to-mid-70s inland, while closer to the coast, they’ll run in the upper 70s. That will help drive heat indices solidly into the 100s, with the highest heat indices expected in the Highway 17 corridor and points east. A Heat Advisory will be in effect for Charleston County and the southern part of Berkeley County from 11am-8pm, when heat indices should exceed 108° and could top out near 111° as the seabreeze pushes by. The aforementioned high pressure will make it much harder for thunderstorms to develop, though a couple popup showers will be possible. With that in mind, though, don’t count on thunderstorms to impart any relief from the heat.
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.
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.
