Standard July warmth and mugginess will continue on Sunday. We’ll start the day in the mid-70s under partly cloudy skies, and we should get the first part of the day in rain-free. From there, we’ll start to see showers and thunderstorms develop by mid-afternoon and make their way into the area from the west and southwest throughout the rest of the evening. The strongest storms could produce strong wind gusts, while heavy rain and frequent lightning will be more widespread concerns. Be ready to bring outdoor activities inside if thunderstorms approach.
Thursday is going to be another hot day across the area. Expect to start the day just barely below 80° inland and likely a couple degrees above it closer to the coast. We’ll warm back into the mid-90s during the day, and with dewpoints not mixing out quite as much — expect them to hang around in the mid-70s — we should see heat indices peak around 110° or so in the afternoon. This is certainly well into the danger zone for heat illness, so please do take it easy if you must be outside. There’s no Heat Advisory as of this writing, but don’t be surprised if one is issued by morning.
Attention then turns to the potential for showers and thunderstorms to move into the area in the afternoon and evening courtesy of a disturbance rounding a retreating ridge of high pressure. Most of these storms should be efficient rainfall and lightning producers, and a few of these storms could be on the strong side with damaging wind gusts the main concern. Hail can’t be ruled out, either. Stay alert to rapidly changing conditions as we get into tomorrow afternoon and evening, and don’t be surprised if there are evening commute impacts.
Fortunately, wildfire smoke will play much less of a role in Thursday’s weather as it continues to disperse southward.
We begin a rather hot stretch of weather — yes, even warmer than we’ve been — starting Tuesday as ridging builds aloft. Downslope flow from the northwest will act to warm the air as it sinks as well as help to keep the seabreeze pinned closer to the coast, which will help drive air temperatures well into the mid-to-upper 90s across the area after an already warm start in the upper 70s to around 80° at the coast. Mix in humidity and you’ll find heat indices across the area ranging from about 105-110° during the height of the afternoon. We’ll be in this heat index “danger zone” for a few days, so be sure to take it easy if you have to be outdoors during this time, and get lots and lots of water.
As the ridge builds aloft, this will also help to put a lid on afternoon thunderstorms for the most part; a shower or storm can’t be totally ruled out, but don’t count on one for any sort of heat relief.
Finally, Canadian wildfire smoke will add a milky haze to the overall sky composition. Upstream observations suggest that there could be some minor air quality impacts, but so far no major issues are anticipated. Stay tuned, though.
Expect one more generally quiet weather day on Thursday (though a shower or storm can’t be ruled out in the afternoon, especially further inland) before things turn more unsettled as a trough digs in for Friday and the weekend.
Somewhat drier air (aloft, anyway) moving into the area Tuesday will put an end to the soggy weather for a few days, though an isolated afternoon thunderstorm does remain possible. We start the day in the low 70s — the coolest start to a day since June 28 — before warming into the low 90s in the afternoon. While the drier air will provide for generally partly cloudy skies amidst a somewhat brilliant blue sky, it’ll still be fairly humid at the surface; expect heat indices to peak around 100° in the afternoon as the seabreeze moves by. All in all, though, we should have plenty of sun to help sop up this latest round of heavy rain.
We have another hot day ahead on Sunday before showers and thunderstorms erupt once more generally in the mid-to-late afternoon and evening hours. Lows in the mid-to-upper 70s will warm to the mid-90s in the afternoon. Ever-so-slightly drier air should keep heat indices below 105° and delay the onset of thunderstorms later than they started on Saturday. Storm coverage also should be a little thinner than Saturday as well. Still, a strong to severe storm can’t be totally ruled out, so stay alert for possible warnings, and just be ready to change outdoor plans to indoor ones if a thunderstorm approaches your area.
More showers and thunderstorms are forecast for Thursday afternoon as a warm and humid atmosphere remains firmly in place across the area. Temperatures will warm to the low-to-mid-90s before storms start to kick up after convective temperatures are met. Shear is weak and instability is about average, but there will still be plenty of moisture to wring out of the atmosphere, so expect frequent lightning and heavy rain with the stronger of Thursday’s thunderstorms. There will be the risk for storms to anchor a bit and rain a lot in one spot as westerly flow aloft fights against an inland-moving seabreeze. (Daniel Island knows all about this, with several stations on the island recording 2-3″ of rain in a couple hours’ time.) A damaging wet microburst or two can’t be discounted either especially near where outflow boundaries collide. Once again, keep an ear out for warnings and take it easy on the commute.
One more round of coastal flooding is possible with the Thursday night high tide at 11:43 PM. Expect water levels between 7.1-7.3′ to produce some minor flooding generally between 9 PM-1 AM. A Coastal Flood Advisory will likely be issued. From there, the astronomical influences of the full moon will wane further, and while water levels may get close on Friday night, we should be done with this round of king tides.
We will not get to declare independence from hot weather this July 4th, that’s for sure: After a balmy start in the upper 70s, temperatures will once again head into the mid-90s in the afternoon with heat indices running between 105-110°. Once again, you’re going to want to make sure you’re getting plenty of water and getting in the shade at times. Headed to the beach? Definitely deploy the sunscreen with the UV index forecast to be at 11, in the “Extreme” category.
As we get further into the afternoon and the seabreeze begins to move inland, we’ll see showers and thunderstorms begin to fire in a reasonably unstable environment. A storm or two could be on the strong to even severe side with gusty winds the main concern. Regardless of severity, the lightning a thunderstorm produces makes them all dangerous. This is especially important on a big outdoors day like the Fourth. Remember: When thunder roars, go indoors!
Finally, there will be a risk for minor coastal flooding with high tide around 9:53 PM. This tide has already caused Folly Beach to cancel their fireworks, unfortunately, and may be problematic for other beach displays as well. Be ready to avoid flooded roadways an hour or two around high tide.
After the first 95° reading of the year on Wednesday, we’ll likely repeat that on Thursday, with plenty more 90s to come as we head into the holiday weekend. Downslope flow should once again keep dewpoints in the mid-60s, thus keeping heat indices in check as well. Expect partly cloudy skies — and as always, a shower can’t be totally discounted — but overall expect a rain-free, warm day.
A cold front will move through and stall out nearby on Tuesday, allowing drier air to mix into the area. This will largely suppress cloud cover and will help drive temperatures to the mid-90s in the afternoon; fortunately, the drier air mixing in will also keep dewpoints reasonably in check, so heat indices will only top out around 96°-98° or so.
A few thunderstorms will still be possible very early Tuesday morning, but widespread severe weather does not look to be an issue. Still, there’s a small chance you could be woken up overnight, especially the further north you go.
