On Monday, April 4, the dry weather gave way as high pressure shifted offshore. With a return of moisture increasing overnight, low temperatures were in the mid to upper 40s, with highs in the low to mid-70s.
The main weather event during the period occurred on Tuesday when a warm front lifted north across the state, helping to trigger a severe weather event south of the Fall Line, with heavy rain, strong winds, and tornadoes. Some locations in the Central Savannah River Area (CSRA) and Midlands recorded between three and four inches of rain, prompting flash flood advisories to be issued in portions of Columbia. Supercell and severe thunderstorms spawned 13 tornadoes, including an EF3 tornado that moved through the town of Allendale and another EF3 that touched down in Allendale County and was on the ground for nearly 35 miles until it lifted in Orangeburg.
Another round of severe weather occurred on Wednesday, though not as prolific as the event on Tuesday, as the cold front associated with the same weather system started to move through the state. 1.75” hail was reported in Hampton and Berkeley counties, and a funnel cloud was reported near Moncks Corner in Berkeley County. Heavy rain near Trenton in Edgefield County and the surrounding area contributed to flooding in low-lying portions along the Savannah River and Augusta.
The lingering cold front caused additional thunderstorms on Thursday, which produced hail in Charleston and Horry counties, including baseball-sized hail near Galivants Ferry. The cold front had pushed offshore, and breezy, cool conditions built into the region by Friday. Even though skies were clear, high and low temperatures were between five and ten degrees below normal, with minimums in the upper 30s to upper 40s and daytime temperatures reaching the 60s. The dry and unseasonably cool weather continued into the weekend. Highs on Saturday reached the mid to upper 50s, up to twenty degrees below normal. Under a surface high pressure, overnight temperatures dropped into the upper 20s in the Upstate, to mid-30s closer to the coast, and rose throughout the day into the upper 60s and low 70s.
(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 | 1.97 | 13.76 | 0.3 |
| Greer Airport | 1.55 | 15.77 | 2.0 |
| Charlotte, NC Airport | 1.56 | 14.42 | 2.6 |
| Columbia Metro Airport | 4.03 | 12.00 | 0.6 |
| Orangeburg 2 (COOP) | 4.22s | 15.56s | 2.9 |
| Augusta, GA Airport | 3.99 | 12.94 | 0.2 |
| Florence Airport | 1.75 | 11.84 | 1.6 |
| North Myrtle Beach Airport | 1.34 | 10.36 | -0.4 | Charleston Air Force Base | 2.87 | 8.00 | -2.9 |
| Savannah, GA Airport | 0.58 | 6.61 | -4.2 |
| *Weekly precipitation totals ending midnight Sunday. M - denotes total with missing values. s - denotes total with suspect data. |
4-inch depth soil temperature: Clinton: 55 degrees. Columbia: 61 degrees. Barnwell: 52 degrees. Mullins: 55 degrees.
Severe weather at the beginning of the period produced excessive rainfall across portions of the state. Widespread rainfall totals of at least an inch were measured statewide; however, a swath of rain exceeding two inches fell across the Central Savannah River Area, Midlands, and Pee Dee. Most of Aiken, Edgefield, and McCormick counties reported over four inches of rain, with isolated pockets receiving over six inches. A CoCoRaHS observer near Moncks Corner in Berkeley County recorded 5.79 inches of rain. Over the past few weeks, rainfall has helped alleviate abnormally dry conditions (D0) and moderate drought (D1) in some areas; however, these conditions persist in the state's eastern half.
With heavy precipitation falling across the middle of the state, streamflow values at gauges in the impacted area increased to above normal flows. Some ACE Basin gauges reported much above normal flows after weeks of reporting below normal flows. Similarly, the gauges on the Little Pee Dee River at Galivants Ferry and the Waccamaw River near Longs, which had been reporting extremely low flows, saw an increase in the streamflow values after the rainfall at the beginning of the period. As the water moved through the state's watersheds, a few river height gauges reached minor flood stage and were forecast to continue to rise. Most of the rivers observed heights below the flood stage.
