More Rain Coming After a Record Wet Winter

Mar 2, 2020

Several more rounds of rain are on the way to the Palmetto State, adding to the record wet winter many areas of the state have officially recorded.

Meteorological winter begins on December 1st and ends on the last day of February each year. The Southeast Regional Climate Center (SERCC) supplies climate data for a six state region, including South Carolina, and its data reveal that several sites across the state have recorded their wettest winter. They include:

Columbia Metro Airport
Anderson Airport
Greenville/Spartanburg International Airport
Florence
North Myrtle Beach

Charleston International Airport recorded its second wettest winter on record, missing its rainest winter in 1963-64 by about 3 inches. Many of these locations have 50 to 75 years of reliable precipitation records, except North Myrtle Beach, which has 21 years of data and Charleston which has more than 90 years of data.

The soggy winter months followed what meteorologists often refer to as “flash drought”, which began late last summer and fall. Hurricane Dorian brushed the South Carolina coast, leaving many residents of the Upstate and Midlands dry. The trend continued after several more hurricanes, including Humberto and Lorenzo, stayed far out at sea. A strong ridge of high pressure over the Southern U.S. — which effectively blocked tropical storms and hurricanes from directly moving into the state — also contributed to the excessively hot and dry conditions at that time.

More Rain Ahead

A proverbial conveyor belt of moisture will continue to stream across Mexico, through the Southern U.S., and into South Carolina this week. Several high-altitude disturbances within this flow will bring an additional 1 to 3 inches of rain over a wide portion of the state. The rain is expected to be spread out over several days and come in waves. As a result, widespread flash flooding is not anticipated, but spotty locations that get underneath persistent heavier showers may see flash flooding, particularly on Tuesday and Wednesday.

The moderate to major flooding along some rivers in the state early in February has subsided over the past few weeks. As of Monday morning, the Edisto River at Givhans Ferry and the Savannah River near Clyo, GA (on the state line), are the remaining rivers experiencing moderate flooding. NOAA’s official forecast brings the Edisto River down to minor flood stage either Tuesday evening or Wednesday morning. If this verifies, the lower Savannah River would be the only river at moderate flood stage or higher.

It is difficult to confidently say for certain whether the wet conditions will continue into the remainder of spring. There are several climatic factors that govern seasonal rainy patterns, including the presence of El Nino or La Nina, thunderstorms in the tropical Pacific Ocean, the concentration of relatively warm air closer to the North Pole (often referred to as “high latitude blocking”), among others. Forecasters from NOAA’s Climate Prediction Center — who examine these and other factors — say odds are favoring a wet and warm spring over the state. The greatest chances for above normal rainfall in their latest outlook are in the Upstate region.

Should these odds play out, the state may be in for more of the same over the next couple of months.