Friday will be the hottest day of 2021 so far. Temperatures will soar into the upper 90s in the afternoon as deep westerly to northwesterly flow in the troposphere pins the seabreeze to the coast, keeping the cooler marine air at bay for much of the day. On the other hand, this will allow very humid air characterized by dewpoints approaching 80° to pool near the coast. When the seabreeze finally begins its inland trek in the mid-to-late afternoon, the highest heat indices will then be realized as this incredibly moist air moves across the much warmer air found over land. Given this potential, an Excessive Heat Watch is in effect for the Tri-County area. Ridging aloft will put the kibosh on any shower or thunderstorm activity, so don’t count on that to bring any relief, either.

If it’s at all humanly possible, avoid exertion in the heat of the day tomorrow. If you must be outdoors, get shade and hydration on a very regular basis. If you begin to feel ill, move into an air-conditioned area immediately. If you feel faint and your skin is hot to the touch, that’s quite possibly heat stroke — a 911-worthy medical emergency requiring swift treatment.

High heat will continue through Sunday, and heat advisories for heat indices approaching 110° are certainly possible. Please take it easy!

We’ll trade the persistent rain of the last few days for a real taste of summer beginning on Thursday. Temperatures will easily rise into the low 90s in the afternoon under mostly sunny skies as high pressure builds in aloft and at the surface. The humidity will make it feel closer to 105°, which is as hot as the heat index has been all summer. Take appropriate precautions: Plenty of water, plenty of shade, and most importantly, look before you lock. One hot car death is too many.

Today will continue to feature scattered showers and thunderstorms, especially this morning as slow-moving storms develop and move in from the west. Flooding will certainly be a concern wherever thunderstorms set up and rain for long periods. The next high tide will be at 12:07 PM.

It won’t rain all day, however; high-res models have this batch of storms eventually fizzling out by early this afternoon. Another round of storms could fire along the coast this evening, and this may drive additional heavy rain concerns before departing later tonight.

This will be our last day in the 80s until next week; the hottest temperatures of the season will begin Thursday and last into Sunday with highs well into the 90s and heat indices approaching 110°. (More on that later today.)

We’ve got a muggy and potentially soggy Tuesday ahead. While it won’t rain all day, expect plenty of shower and thunderstorm coverage to bring just about everyone some rain at some point tomorrow. Given plentiful tropical moisture, some of this rainfall could become quite heavy at times, leading to the potential for isolated bouts of flooding where the heaviest rain falls. Heavy rain will be possible possibly as soon as shortly after daybreak, similarly to today, as it likely won’t take much heating to start convection. We’ll want to watch the 11:18am high tide closely as high-resolution guidance suggests storms in the area around that time.

Temperatures will remain on the warm and muggy side. We’ll start in the upper 70s across much of the area, with 80° lows possible along the coast and in downtown Charleston. Highs will only top out in the upper 80s given the expected shower and thunderstorm coverage.

High rain chances continue into Wednesday before moisture departs and we heat up for Thursday and especially on Friday, which could be the hottest day of 2021 thus far if the forecast of 96° remains on track. Stay tuned.

We start this Thursday with temperatures already approaching 80° as of 8am. Highs around 90° look to be common before showers and thunderstorms erupt this afternoon.

Today’s setup could portend a flooding event in downtown Charleston this afternoon and evening. Westerly winds look to pin the seabreeze closer to the coast, and with a front advancing from the north, there will be numerous focal points for showers and thunderstorms to develop. Atmospheric moisture is readily available, with precipitable water values running over 2″ once again today (anything 2″ or over generally requires more scrutiny for flooding). Finally, we are in a king tide period, and this morning’s thinking from NWS on tonight’s high tide is that it will fall just short of the 7′ level at which sunny-day salt water flooding typically begins. (It may yet be high enough, though, to begin to produce some flooding on Fishburne and Hagood.)

Guidance suggests that showers and thunderstorms generally should start to form between 1-3 PM. Storm motions will approach the coastline today, and with a seabreeze trying to push the opposite direction, this certainly invites concern about heavy rainfall stalling out for a period of time. The high-resolution model ensemble this morning once again paints a 30% chance of 3″ of rain in 3 hours across the metro area this evening, further lending credence to this concern. While this isn’t a slam dunk, it’s important to keep an eye on the weather today as impacts to the evening commute are certainly in the cards. More on this later today — stay tuned.

We look to have another wet day ahead, with some showers already popping up west of the Ashley as I write this. The best chance for showers and thunderstorms will again be later this afternoon into this evening. There will once again be a chance for localized heavy rain, with a 30% probability of 3” of rain in 3 hours once again being indicated by the high-resolution ensemble data. Yesterday this bore out in the 17-A corridor headed into College Park, with floodwater on the ground for a few hours after the main rain event. Thus, we are going to need to watch radar trends carefully, noting that high tide will be coming up at 5:39 PM.

Clouds and rain will keep temperatures a few degrees below normal, with highs in the mid-80s expected across the area. A few peeks of sun aren’t out of the question, allowing temperatures in a few spots to perhaps jump quickly. Humidity will still factor in, though, and it’ll feel closer to 94-95° in the afternoon.

Try to stay dry and weather-aware once again today!

We’re starting today with partly cloudy skies and muggy temperatures in the mid-70s. This will give way to 90s ahead of the seabreeze this afternoon; heat indices will push 100° with low 70s surface dewpoints in place. Showers and thunderstorms will fire on the seabreeze possibly as soon as noon-1pm, which could portend some rainfall or lightning concerns at area beaches early this afternoon. The seabreeze will then make its usual daily inland trek, bringing the risk for showers and thunderstorms more inland with time. This will happen as a mid-level disturbance moves into the area, which will enhance the coverage of showers and thunderstorms today into tonight. Some areas of heavy rain are certainly possible, with the high-resolution model ensemble painting a 10% chance of 3″ of rain in 3 hours across the entire coastal plain. This could lead to isolated bouts of flooding, so we’ll want to watch this closely throughout the day.

Rain chances will continue overnight into Monday, with the risk for heavy rain continuing throughout the day Monday. More on that later today as we get the daytime guidance package in.

We’re in full-blown Command-C/Command-V mode here at @chswx HQ this week, as one would typically expect in a Charleston summer: Highs in the low 90s with isolated afternoon thunderstorms expected. This forecast is right on the dot with mid-July climatology, and there’s really not too much else to write home about.

If you’re headed to the beaches or out on the water this morning, there is the risk of a waterspout underneath any tall cumulus towers, and there will be a persistent rip current risk all day. These are the only caveats — mind these and you’ll be in good shape.

The work week rolls on with pretty standard July weather as we remain under the influence of Atlantic high pressure. We’ll stay warm and muggy with lows in the low to mid-70s away from the coastal communities (where lows likely won’t dip below 80°). Highs each afternoon will continue to top out around 90-91° — right around where we should be for this time of year. Rain chances come down a touch on Friday, with mostly sunny skies currently expected.

Overall, brief heavy rain will be possible within any thunderstorms, though storms today did show a propensity to train a bit, with 2″ of rain recorded at a gauge in Mt. Pleasant within a persistent round of thunderstorms earlier today. The strongest storms could produce sporadic wind damage, but widespread severe weather is not in the forecast by any stretch.

Rain chances stay around normal for July heading into the weekend before ramping up a bit as we get into next week.

Another rather normal July day is in store for Tuesday. Expect a muggy start with lows in the mid-70s heading toward a high of around 90° in the afternoon. Like today, scattered showers and thunderstorms will factor into the weather picture possibly right out of the gate in the morning near the coast. This scattered storm risk progresses inland during the day with the seabreeze, leaving rain-free conditions in many spots by evening.

Heat indices will peak in the mid-90s in the afternoon, particularly around seabreeze passage as dewpoints surge in its wake, so be aware if you’re working outside around this time.