The period started on Monday, April 26, with ridging and high pressure over the Southeast, which would lead to dry and warm weather through Thursday. With clear skies overnight, morning lows dropped into the mid- to upper 40s due to radiational cooling, and daytime highs rose to near normal values in the mid- to upper 70s. Lows on Tuesday morning were slightly cooler than normal, in the 50s, while afternoon temperatures climbed into the low 80s across much of the state.
The first King Tide cycle for 2021 started on Tuesday, and the tidal gauge in the Charleston Harbor reached 7.53 ft MLLW on Tuesday evening and 7.40 ft on Wednesday evening. There were multiple reports of shallow saltwater flooding in downtown Charleston and low-lying areas along the entire South Carolina coast.
Temperatures continued to rise through the remainder of the workweek, with both high and low temperatures up to ten degrees above normal. The National Weather Service (NWS) station at the Greenville-Spartanburg International Airport recorded a high of 83 degrees on Wednesday, April 28. High pressure moved off the coast on Thursday, winds picked up in the afternoon, and gusts up to 35 mph were measured across the Midlands. A cold front moved through the area overnight and pushed through the state on Friday. There was limited rainfall associated with the front, resulting in less than a tenth of an inch in the Upstate.
The South Carolina Forestry Commission (SCFC) called for a Red Flag Fire Alert on Friday for the state through the remainder of the period due to low relative humidity values and dry conditions. High pressure settled into the region behind the front, keeping temperatures near normal and suppressing any chance of rain on Saturday and Sunday.
(Note: The highest and lowest official temperatures and highest precipitation totals provided below are based on observations from the National Weather Service (NWS) Cooperative Observer network and the National Weather Service's Forecast Offices.)| Weekly* | Since Jan 1 | Departure | |
|---|---|---|---|
| Anderson Airport | Trace | 12.80 | -2.6 |
| Greer Airport | 0.04 | 16.47 | 0.6 |
| Charlotte, NC Airport | 0.00 | 15.14 | 1.2 |
| Columbia Metro Airport | 0.00 | 15.94 | 2.2 |
| Orangeburg Airport | 0.00 | 10.38M | -4.2M |
| Augusta, GA Airport | 0.00 | 17.73 | 2.7 |
| Florence Airport | 0.00 | 14.93 | 2.7 |
| North Myrtle Beach Airport | 0.00 | 15.15 | 1.0 |
| Charleston Air Force Base | 0.00 | 13.39 | -0.1 |
| Savannah, GA Airport | 0.00 | 14.14 | 0.7 |
| *Weekly precipitation totals ending midnight Sunday. M - denotes total with missing values. |
4-inch depth soil temperature: Clinton: 71 degrees. Columbia: 72 degrees. Barnwell: 66 degrees. Mullins: 68 degrees.
After the welcomed rain last week, much of the state reported little to no rainfall over the period. Totals over the seven days amounted to less than a tenth of an inch in parts of the Pee Dee and Upstate. The remainder of the state recorded no rainfall, and the United States Drought Monitor expanded the abnormally dry conditions (D0) across the region. April 2020 was one of the driest Aprils on record for many locations, including the NWS station at the Florence Regional Airport, which recorded only 0.15 inches of rain during the month.
Most of the streamflow values across the state remained near normal values. Due to the continued lack of rainfall across the region over the recent periods, streamflow gauges on the Black, Little Pee Dee, and the Waccamaw reported below normal streamflow values, and river height levels across the entire state were below flood stage.
