Much needed rainfall is in the forecast over the Palmetto state this week, and periods of heavy rain could pose the risk for flash flooding.
In the latest drought monitor released by the United States Department of Agriculture on Thursday, June 23, most of South Carolina was classified as under abnormally dry or moderate drought conditions. Over the southern tip of the Low County, in Jasper and Beaufort counties, conditions were more serious, and the region was classified as under a severe drought.
From the Midlands to the Low Country, month to date precipitation accumulations range from between two to three inches below normal. Year to date, departures in these regions are up to five inches below normal. According to hydrological calculations, nearly five to 10 inches of rainfall will be needed in some spots to alleviate the drought that has developed. Although these amounts will not be addressed in one weather event, relief is on the way.
On Monday morning, a trough of low pressure was draped over Dixie Alley, while a cold front was approaching the Mid Atlantic from the Tennessee Valley and Appalachians. At the same time, a rather humid airmass was beginning nudge into the area. Over the next several days, the frontal boundary is expected to stall over South Carolina and atmospheric moisture levels will remain elevated. These conditions will prime the environment for scattered downpours, capable of producing locally heavy rainfall rates.
According to model guidance, shower chances will be greatest over the northwestern half of the state on Monday. Thunderstorm activity should expand to cover the entire state by Tuesday, and these storms could drop excessive rainfall over a short period of time. Forecasters at the Weather Prediction Center have placed portions of the Palmetto State under a level one out of five risk for flooding for the next several days. Over the three-day period from Monday morning to Thursday morning, two to four-inch accumulations are possible in some parts of the Midlands and Low Country. Isolated pockets of four to six inches accumulations are possible in the higher elevations of the Upstate. Should the forecast verify, these amounts will not totally alleviate the drought, but they should lessen its severity.
By the end of the week, the weather pattern is expected become more typical for this time of year: Rain and thunderstorm chances will mostly be confined to the afternoon.