High pressure wedging southward across the area has brought some cooler and drier air to the area this evening, with dewpoints falling into the mid-60s (it’s been a minute!). This will yield a fairly nice (but still warm) day on Thursday. We’ll start the day in the low 70s and warm to the upper 80s in the afternoon under partly cloudy to mostly sunny skies. With the lack of moisture and influence of high pressure, rain isn’t expected (and won’t be for a few days). Overall, not too shabby for mid-August!
Tuesday’s forecast will continue to feature warm temperatures and afternoon thunderstorms as Berkeley and Charleston head back to school. We have another warm start ahead of us — generally expect lows in the upper 70s once again, followed by highs in the low 90s in the afternoon. This should run a couple degrees cooler with a little more onshore flow, but it’ll still be toasty with heat indices peaking around 102° before showers and storms fire. Once again, heavy downpours could cause localized flooding, especially near swollen rivers and streams and in urban areas, so stay alert for possible Flood Advisories.
All Tropical Storm Warnings were dropped this morning as Debby, which made landfall around Bulls Bay at 2am, continues to lift north away from the area. The risk for flooding continues, especially near rivers, creeks, and streams. An Areal Flood Warning remains in effect across the entire Tri-County area through at least 2:45pm. Additional rain should develop courtesy of some wraparound moisture from Debby as we get into the heat of the day, which could inhibit recovery from flooding, so the warning continues. The Flood Watch continues until Friday morning as well.
Temperatures today will run in the upper 80s, closer to normal after a record cool high temperature of 80° on Wednesday. We’ve seen some peeks of sun and blue sky this morning and should hopefully see a bit more of that just for our spirits’ sake. The sun will make a more complete comeback for Friday and the weekend.
Debby made landfall this morning along the Big Bend of Florida as a Category 1 hurricane. It’s since fallen back to being a tropical storm with max winds now at 50 MPH, but its forward speed has been slowing as steering currents collapse around it. This is setting the stage for the well-advertised prolonged deluge and flash flood threat that will unfold particularly over the next couple days.
Tropical Storm Debby, newly christened as of 5PM, will march up the Florida coast on Sunday, strengthening as it goes over 90°+ degree water in the Gulf of Mexico. Here at home, moisture will begin to increase ahead of the storm, and that should lead to scattered to numerous showers and thunderstorms in the afternoon and evening hours. Expect balmy lows in the upper 70s to yield to highs in the upper 80s in the afternoon as the flow begins to turn more onshore and showers and thunderstorms become more numerous. A strong storm or two can’t be ruled out, as is normally the case this time of year.
Heat will be the main weather story on Thursday as air temperatures reach into the mid-90s and dewpoints peak in the mid-70s, combining for heat indices that could approach 110-115° in the afternoon. This has prompted an Excessive Heat Watch from noon-8PM, when heat indices could be highest. If the forecast indicates heat indices approaching or exceeding 113°, this could be upgraded to an Excessive Heat Warning; otherwise, a Heat Advisory would likely be the move barring an unexpected cooler start (like we saw today, in fact!)
Showers and thunderstorms will be possible in the afternoon and evening hours as the seabreeze pushes inland. We could also see storms coming our way from the Midlands once again as well. Widespread severe weather is not expected, but you can never rule out a damaging wind gust or two this time of year.
Well, the respite is decidedly over: we’re back to 100°+ heat indices on Tuesday as surface high pressure shifts offshore and higher-dewpoint air returns to the area. We start the day in the low 70s one more time, but will warm quickly into the 80s by mid-morning and should be back in the 90s by early afternoon. Dewpoints look to climb into the mid-70s throughout the day, and this will yield heat indices around 103° — hot to be sure, but shy of advisory criteria. Scattered showers and thunderstorms are primarily expected in the afternoon and evening hours, though a few showers can’t be ruled out in the morning. A few showers may try to get going on the seabreeze, but high-resolution guidance suggests that the bulk of any activity will get going perhaps in the Midlands and Upstate before dropping southeasterly into the metro. Some heavy rain is possible, and a damaging wind gust or two is not out of the question, either. Keep an ear out for possible warnings Tuesday evening, just in case.
More active weather is expected Thursday as a stalled front combines with a favorable upper-air configuration and plenty of available moisture for numerous showers and thunderstorms. While it won’t rain all day at any one location, be ready for downpours to affect your day. We could see showers and storms fire overnight near the coast, in fact, and those could impact the morning commute, while guidance continues to paint solid afternoon thunderstorm chances as well.
This at least helps drives temperatures down a touch: while the low of 77° is still quite balmy, highs top out in the low 90s at best with heat indices running lower than they have on previous days. (A meteorological Pyrrhic victory, perhaps, but so it goes in late July.)
Heat and humidity will continue to rule the roost for Tuesday and for the next couple days as we stay within southerly flow at the surface and aloft, keeping the moisture pump moving right along. This will also lead to periods of storms. Guidance is hinting at another round of morning showers and storms near the coast as the land breeze develops before afternoon storms develop further inland. Coverage will generally be scattered in nature, and not all of us will see rain as a result. Highs top out in the low 90s after a start in the upper 70s; expect heat indices to get close to advisory criteria in the afternoon, perhaps approaching 107°.
A stalling front will briefly usher in slightly drier air on Thursday, helping to keep heat indices below heat advisory levels, but it’ll still be plenty warm with air temperatures peaking in the mid-90s and heat indices in the mid-100s expected. We should still see a few showers and thunderstorms pop in the afternoon, but like Wednesday, coverage should be reasonably limited.