Wednesday will be another quite hot July day ahead of the usual round of scattered afternoon thunderstorms. After a very muggy start — lows in the upper 70s inland, probably not getting below 80° downtown and at the beaches — expect air temperatures to top out in the low-to-mid-90s across the area. Mix in dewpoints running in the mid-to-upper-70s and that’ll yield heat indices approaching 107° in the peak of the afternoon. You’ll definitely want to be taking frequent breaks and getting plenty of water if you’ll be outside for an extended period tomorrow. (Note that Heat Advisory criteria for July onward is heat indices at or above 110° for more than two hours, so while these heat indices would have garnered an advisory last month, they will not in this case.)
Showers and thunderstorms should once again develop along and ahead of the seabreeze in the afternoon. The atmosphere will be primed for a strong storm or two, with plenty of available energy for storms to tap into once the capping inversion erodes. Damaging wind gusts and maybe even some hail will be possible in the strongest storms, while all storms will be capable of locally heavy rain and frequent lightning. Not everyone will see severe weather, much less a storm at all — coverage looks scattered at best. But if you do, it could be a good one.
As is customary for the Lowcountry, heat and humidity will feature prominently in the Independence Day forecast, with some scattered afternoon and evening thunderstorms to cool some of us off. Before thunderstorms fire, we should see temperatures reach into the upper 80s to low 90s away from the somewhat cooler (but still quite humid) coastline. This warmth when combined with mid-70s dewpoints will yield heat indices in the low 100s for tomorrow. Be sure to get plenty of water and shady breaks if you’re outside for an extended period. (Don’t forget the sunscreen, either.)
By 1-2 PM, we should begin to see some showers and thunderstorms start to initiate along and inland of the seabreeze circulation. We’ll want to watch the 1-4PM period closely for the greatest risk for lightning to the beaches as there will be more than ample instability for strong updrafts to develop. (Remember: When thunder roars, go indoors!) Places that get caught under a thunderstorm will not see it move too terribly much during its lifecycle; with precipitable water values at or exceeding 2″, we could see some pockets of rather heavy rain in a short time in some spots. Wind shear is nearly nonexistent, so severe weather looks quite unlikely outside of the potential for a wet microburst somewhere. Severe potential aside, lightning makes all thunderstorms dangerous, so please do move indoors if you see lightning or hear thunder.
The good news, though, is that the Fourth of July will not be a complete washout. We should see storms begin to clear the Tri-County by early evening as the seabreeze progresses inland, and fireworks shows should be very much go for liftoff. Have a safe and fun holiday!
After record rainfall today — 1.87″ of rain at the airport breaks the record of 1.54″ set in 2000, while stations in West Ashley picked up 2.5-3″ — more storms are on the horizon for the next few days as we remain within a very humid airmass with plenty of upper-air and surface features to help spur on shower and thunderstorm development.
Thursday looks to go similarly to the past couple days, though there may not be quite as much coverage as we’ve seen thus far this week. We could see showers and storms forming early in the day near the coast, with storms becoming scattered to numerous while translating inland with the seabreeze throughout the afternoon. With precipitable water values near 2″, we once again could see pockets of very heavy rainfall. The past couple days have seen a couple 4″ bullseyes, and I can imagine that will be the case somewhere again tomorrow. The severe weather risk remains very low given the very saturated atmosphere, but lightning and isolated bouts of excessive rainfall will make any thunderstorm dangerous. High temperatures will remain suppressed in the mid-80s, though the humidity will still be rather swampy.
Showers and thunderstorms return to the forecast on Tuesday as a front sinks into the area and stalls out. A good bit of you should see at least some rain tomorrow and over the next few days as the stalled front continues to hang around with plenty of available moisture. Given the time of year, of course, not everyone will see the same amount of rain — some of you could see very little, while others may be crying “Uncle!” by the time the week is over. It all ultimately depends on small mesoscale accidents that are impossible to predict with more than an hour or two of lead time. On average, a half-inch to an inch of rain in spots through the end of the week looks pretty reasonable.
Showers and storms will keep us out of the 90s for the foreseeable future, too. Tuesday will run in the upper 80s, but we should see temperatures suppressed solidly in the mid-80s for the rest of the week with the ongoing unsettled pattern. It looks like we’ll keep elevated storm chances into the holiday weekend, too, so be thinking about a backup plan for your outdoor activities to celebrate the Fourth.
Thursday will be the hottest day this week as air temperatures return to the mid-to-upper 90s across the Lowcountry in the afternoon. Unfortunately, dewpoints will also have recovered back into the 70s, and that could put us close to heat advisory territory for Thursday afternoon as heat indices could approach 105°. There will, however, be a shot at some isolated thunderstorms later in the afternoon into the evening hours as the seabreeze makes its move inland. Lightning and gusty winds will be the primary concern from any thunderstorm that forms, but so far widespread severe weather doesn’t look likely.
Folks, we’ve been handed a gift: A very not-humid, spring-ish mid-June day for Father’s Day. We start the day with lows in the mid-60s away from the coastline under mostly clear skies. Temperatures will warm into the mid-80s in the afternoon while dewpoints mix out into the 50s — very rare air for this point in the year around here. This will yield relative humidity values below 40%, and as such, a wonderful Father’s Day gift from Mother Nature. We’ll have a few clouds from time to time, so make sure you’re using sunscreen, but other than that, there are no weather concerns. Enjoy!
Another hot day lies ahead as air temperatures head back up to the mid-90s thanks to downslope flow from the Appalachians. Said downsloping, though, will help keep dewpoints — and the heat index — from getting too far out of bounds. Heat indices will “only” peak around 100° this afternoon. While still quite hot, we aren’t headed into that more dangerous temperature territory today as a result of the drier air. This will also essentially suppress thunderstorm development; in fact, today marks the beginning of what looks to be a rain-free few days across the area. With just a few clouds expected, definitely deploy the sunscreen as the UV index approaches 11 during the peak of the day.
Thursday will run a little cooler — 91° with a heat index of 94° certainly qualifies — as onshore flow behind a backdoor cold front gives us a little break before the heat picks back up on Friday. With the slightly cooler weather comes a somewhat more stable atmosphere, which will keep the risk for afternoon showers and thunderstorms to a bare minimum. All in all, should be a fairly decent day for an outdoor dinner. (Might still be a bit much for eating lunch outside, though.)
Another dangerously hot day for the Lowcountry is on tap for Tuesday, as temperatures soar into the upper 90s — and perhaps over 100° well inland — in the afternoon courtesy of an anomalously strong ridge of high pressure aloft. Factor in the humidity, and it’ll feel as hot as 110°+ during the peak of the afternoon, prompting a Heat Advisory from 11am to 7pm for the entire Tri-County area.
We haven’t seen heat like this in a long while. The last time air temperatures reached Tuesday’s forecast high of 98°, COVID wasn’t even in our vocabulary: it was August 10, 2019.
Looking for thunderstorms to help temper the heat? Don’t count on them, as coverage should be isolated at best. If storms do get going, they’ll be able to take off and become severe with damaging wind gusts and large hail. We’ll also be watching areas to our north with close interest tonight into tomorrow, as a potential mesoscale convective system could move into and through the Mid-Atlantic states during the day. This could help drive a cold front southward, bringing with it perhaps a better shot at some showers and storms later in the evening. These, too, could be on the strong side. The Storm Prediction Center outlines the area in a marginal (1 out of 5) risk for severe storms Tuesday.
Oppressive heat looks to continue for much of the rest of the week, with a slight downshift in intensity Thursday and Friday (but not enough to elude more Heat Advisories). Mercifully, this heat wave should break on Sunday after another front pushes through the area and actually cools things off somewhat. But for now, make sure you’re getting plenty of shade and water if you must be outside in the afternoon.
Coastal flooding will continue to be an issue as well around the times of evening high tide. Watch for the potential for road closures each evening, and be on the lookout for Coastal Flood Advisories from the National Weather Service.
Despite the air temperature topping out around 91°, Thursday’s going to be the hottest day of the week because of quite a bit of humidity. Heat indices could approach 100° in the afternoon before scattered thunderstorms develop along the inland-moving seabreeze. A storm or two could be on the strong side where outflow boundaries intersect, but as is typical in the summertime, any severe weather will be quite localized. Heat will certainly affect everyone, though, so be sure that you’re getting plenty of water and shade if you’re outdoors in the height of the afternoon.
