Jared Smith founded @chswx on Twitter in 2008 as an experiment in disseminating weather data through social media. In the ensuing decade-and-a-half, @chswx has provided live coverage of tropical cyclones, tornadoes, severe weather, and even a couple bouts of winter weather to the good people of Charleston, SC.
Thursday should be generally quiet across the metro area for the vast majority of the day as dry air characterized by dewpoints in the mid-60s — about as good as it gets at this point in the year — hang around for one more day. Expect the day to start in the low 70s once again with highs warming to the upper 80s in the afternoon. Clouds will be on the increase throughout the day as a disturbance approaches, with a slight chance of showers after sunset, but again, the vast majority if not all of us get Thursday in rain-free.
After the fourth-warmest July on record at North Charleston, we catch a bit of a break from the high heat as we get over the hump into the rest of the work week as highs only look to get into the mid-to-upper 80s through Friday. The drier air will be quite noticeable especially Wednesday and Thursday mornings as lows look to dip into the low 70s. The drier air will also act to keep shower and thunderstorm chances to a minimum Wednesday and Thursday, with maybe a popup or two on the inland-moving seabreeze in the afternoons.
Rain chances head back up on Friday as high pressure weakens and moisture surges back into the area. We’ll likely see off and on showers and storms break out with just a little sunshine, continuing throughout the day. Some very heavy rain will be possible at times, and we’ll need to watch for the risk for flooding in a few spots with fairly slow storm motions expected.
Finally, onshore flow with the recent full moon will continue to drive tides into flood stage over the next couple nights. The water level peaked at 7.93′ at 8:48 PM on Tuesday evening, and water levels between 7.6-7.8′ look probable for Wednesday evening. Expect road closures downtown as a result. Keep an ear out for Coastal Flood Advisories from the National Weather Service.
We start August with a relatively “cool” day, at least in contrast to that second half of July we just had, anyway. We start the day in the low 70s before temperatures head to the upper 80s in the afternoon. A little drier air will be mixing in, but it’ll still be humid enough to get heat indices into the mid-90s. Still, though, this is what passes for improvement at this time of year.
A few thunderstorms will be possible in the afternoon, though we shouldn’t see the high coverage that we’ve seen the past two nights. The risk for severe weather is a little lower, too.
The main fly in the ointment on Tuesday evening will be tidal flooding; high tide around 8:43 PM should top out around 7.3-7.5′ in the harbor, producing minor to moderate coastal flooding and likely causing some road closures, which were observed with Monday evening’s 7.52′ high tide. Be ready to route around flooding if you have plans downtown Tuesday evening.
The week ahead starts out unsettled as a front meanders in the area before we “cool off” a bit heading into mid-week as the aforementioned front pushes south, ushering in a slightly cooler and drier airmass. Ridging then builds back in to warm us up later in the week.
The brief interlude away from the mid-90s air temperatures that have punctuated a fair bit of July will end Sunday as a tropical low and its associated showers and thunderstorms moves away. We’ll start the day in the mid-70s before highs top out in the mid-90s in the afternoon; mix in humidity and we should see heat indices around 105-106° around peak heating.
Scattered showers and thunderstorms should fire later in the afternoon into the evening hours and head coastward within northwest flow. A storm or two could get strong enough to produce a damaging wind gust or two, so we’ll want to watch that potential closely. Not everyone will see rain and storms, but if you do, be ready to move outdoor activities inside.
Periods of showers and thunderstorms will figure somewhat prominently into Saturday’s forecast as a low pressure system moves across the area. The feed of moisture and shower and thunderstorm coverage should help keep highs from getting into the 90s, though even upper 80s combined with rich mid-70s dewpoints yield heat indices in the upper 90s. The tropical moisture feed could lead to some very heavy rain in some spots, with nuisance flooding possible where the heaviest rains set up. It won’t rain all day in any one location, either, but expect interruptions to outdoor activities.
Sunday should be a little quieter rain-wise (at least to start) as the disturbance lifts away. This will let temperatures head well into the mid-90s, yielding heat indices 105-110°. Scattered showers and thunderstorms should develop in the afternoon and evening hours, and there is a small chance of a thunderstorm complex trying to make inroads into the area later in the evening, so be ready to dodge those if being out Sunday is in your plans. All in all, no washout, but just be flexible.
Heat indices head back into the danger zone for Friday and the weekend as an uptick in moisture within onshore flow sends dewpoints up into the mid-to-upper 70s. This will also help in bringing scattered to numerous showers and thunderstorms ashore across the area, perhaps as early as the morning, pressing inland with time with the seabreeze as the day goes on, much like Thursday. We’ll see a similar setup on Saturday, while Sunday should feature a more standard afternoon/evening thunderstorm configuration. The good news is that rain will not hang out terribly long in any one location, and should represent nothing more than a brief inconvenience.
Highs on Friday top out around 90° and in the low 90s on Saturday, while air temperatures warm into the mid-90s on Sunday. Heat indices will head above 105° each afternoon thanks to the aforementioned tropical air. Sunday could feature heat indices approaching 110°, which could lead to a heat advisory. Be cautious if you are out and about during the heat of the afternoons over the next few days!
Standard late-July weather continues for Thursday. We’ll see primarily partly cloudy skies across the area with highs topping out in the low 90s ahead of the seabreeze. Heat indices should top out around 103° or so, with some locally higher values closer to the coast possible for a brief time as the seabreeze moves inland. Said seabreeze should be responsible for a few showers and thunderstorms during the afternoon hours, moving inland with time. Some locally heavy rainfall and gusty winds will be possible in the strongest storms, but they shouldn’t last terribly long at any one location.
Not too much to write home about in the weather department for the rest of the work week — just more in the way of heat, humidity, and a slight uptick in showers and storms as we head toward Friday.
Air temperature-wise, Wednesday will be the warmest day of the rest of the work week with highs topping out in the mid-90s. However, drier mid-level air will mix down to the surface during the heat of the day, and this will help keep heat indices around 100-101°. (Not great, but it could be worse.) The aforementioned dry mid-levels should keep most, if not all, shower and storm activity at bay, though you can never truly rule any stray shower or storm out during this point of the year.
Moisture starts to return Thursday, and this manifests itself with a little higher heat index in the afternoon — approaching 105° — and a slightly better (but still low) chance of seabreeze thunderstorms. Friday could see a little better coverage of afternoon thunderstorms as heat indices top out over 105° at peak heating. (Remember, heat advisory criteria for July 1 and beyond is 110° for two hours.) Overall, there’s nothing in this forecast that’s terribly out of bounds for this point in the year — just mind the heat and be ready to head inside if a thunderstorm gets close.
Tuesday’s forecast looks relatively benign across the area as partly cloudy skies dominate thanks to increasingly drier air aloft. We’ll start the day in the low 70s away from the coast before highs top out in the low-to-mid-90s in the afternoon. Heat indices should top out in the low 100s with low-70s dewpoints across the area. A shower or storm can’t be ruled out along the seabreeze, but most of us should get Tuesday in rain-free.