“Speak Now” (Taylor’s Version) is not the only thing that’s going to get replayed over and over this weekend — so it shall be with the forecast as well. Expect muggy starts in the mid-70s each morning (with temperatures struggling to get below 80° downtown) followed by high temperatures in the mid-90s each afternoon. Heat indices will peak around 105° each day. While that would be a Heat Advisory in June, it happens so frequently in July and August that the criteria is moved to 110° on July 1. So, even though there’s no advisory, the risk for heat stroke is elevated in the afternoons.
From there, scattered showers and thunderstorms will fire along and ahead of the seabreeze as convective temperatures are reached, eliminating the cap that we’ll start the day with. Heavy rain and frequent lightning from slow-moving storms are the main concerns, and these will once again be mostly pulse-type storms (essentially pop up and fizzle out, much like Friday’s storms) with very weak wind shear in place. However, a damaging wind gust or two can never be totally ruled out where outflow boundaries get together and help improve lift, leading to stronger storms.
All in all, don’t expect a washout, but just be ready to move outdoor activities indoors at a moment’s notice. And stay hydrated!
Afternoon showers and thunderstorms remain in the forecast for Friday and the weekend with an active seabreeze and plenty of heat and humidity. Highs each day will top out in the low to mid-90s, with heat indices over 105° expected. Sunday’s heat index could approach 110°, in fact. Airmass showers and thunderstorms will be possible in the early afternoon, with more activity kicking up along the inland-moving seabreeze as we head into the evenings. As always, keep up to date with forecast changes as small tweaks — such as the pocket of drier air aloft that enveloped the area Thursday, which kept thunderstorms to a dull roar — could mean a better (and vice versa) day of weather.
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.
