Endless rounds of rain take over South Carolina; flash flood risk

South Carolina remains under an active weather pattern for much of this week. There is a series of low-pressure systems traveling over the Southeast and another one that could develop into a tropical system later this week just offshore, more on this later. All this instability, combined with moisture, will create prolific thunderstorms across the Palmetto State. The risk for flash floods continues on Tuesday, mainly impacting the Upstate, the southern portion of the Midlands, and the Lowcountry.  There’s a slight risk of flash floods happening across this region. By Wednesday, the risk for flash floods will take over much of the state, but I’ll remain on level one out of four, marginal.

Between Monday night and Wednesday night, the heaviest rainfall is expected to have an impact on the upstate. Areas will receive between 2 and 4 inches of rain, but isolated areas could get above 5 inches of rain. The Midlands will also expect rainfall between 1 and 3 inches. While the coastal region, the Pee Dee, and the Lowcountry will also experience rainfall between one and 3 inches, some isolated amounts, especially across the Lowcountry, could reach 5 inches.

We’re not expecting organized, severe thunderstorms, but these showers will mostly bring continuous rounds of rain and thunderstorms that will enhance the risk for flooding. Make sure you stay away from flooded roads. Water could be deeper than expected. Six inches of water could make your vehicle stall, and 12 inches of water could make your vehicle float.

Temperatures are taking a dip, finally. The clouds and thunderstorms will keep the highs between the low 70s across the Upstate, while the temperatures will rise to around the mid-80s across the rest of South Carolina. With clouds lingering even at night, the lows will remain between the upper 60s and low 70s, and very muggy.

One of these slow pressure systems traveling over our area could develop into a tropical system by the end of the week once it moves over the Atlantic, a few hundred miles off the coast of Georgia or South Carolina. We will continue to monitor the tropics closely, but most importantly, we will bring you prompt updates about the rounds of heavy rains and their impact. Dexter does not represent a threat to South Carolina as it is moving away, over the open Atlantic waters.

Further away, a tropical wave could enter an area (highlighted in orange) over the open Atlantic. The National Hurricane Center gives it a medium chance to develop, but it is possible that this wave could be entrenched by dry air, which would put a halt to its development or its strengthening. Regardless, it is something to monitor but not something to worry about at this point. It is too far away, and if a system develops, it is likely to stay over water.