The clash of cold, dry air over the Central U.S. with warm, moist air over the Southeast U.S. provided the set-up for a significant tornado outbreak from April 12-13, 2020. The system developed early Saturday (4/11), producing tornadoes and 2-to 4-inch diameter hail across Texas to Nebraska. On Easter Sunday (4/12), the storm system spawned tornadoes across six states, including two powerful EF4s. Severe weather continued overnight and into early Monday morning, where it impacted the entire state of SC. As of this report, there have been 137 confirmed tornadoes across 10 states, with 35 significant tornadoes (EF2+), and a combined length of damage paths of over 900 miles. A preliminary report and climatological perspective of the tornado outbreak in South Carolina can be found at the following link: April 13, 2020 Tornado Outbreak
After the severe weather to start the period, the rest of the week was comparatively calm. A weak front remained along the coast, allowing for additional showers and thunderstorms to develop on Tuesday and Wednesday, though none of these storms reached severe limits. Temperatures rose from the 50s into the upper 70s to low 80s on Tuesday, however, maximum temperatures were much cooler on Wednesday, reaching the mid-50s to low 60s. The National Weather Service (NWS) station in Andrews reported a low maximum temperature of 52 degrees, breaking the previous record of 62 degrees set in 2016. The 48-hour rainfall totals ending on Wednesday morning ranged from up to four inches in the Charleston Area and portions of the Upstate to just below an inch in the Central Savannah River Area and northern Midlands.
As drier air moved into the Southeast during Wednesday night into Thursday morning, overnight low temperatures dropped into the upper 30s, prompting frost advisories to be issued for some locations. The fair weather remained in place across the region heading into the weekend, with seasonable temperatures, with lows in the upper 30s to low 40s, and highs in the upper 60s to low 70s. A weak storm system brought isolated showers and thunderstorms across the state Friday evening and into early Saturday morning, but quickly moved out of the region, allowing for blue skies by the afternoon. Another round of severe weather impacted the state on Sunday, April 19, though it was not as widespread or intense as the event the previous Monday. A strong low pressure moved across the Gulf Coast, producing thunderstorms across the Lowcountry that caused localized wind damage in Japer and Beaufort counties. The NWS station at the Hilton Head Airport reported a wind gust of 47mph.
(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 | 2.19 | 23.97 | 9.8 |
| Greer Airport | 1.90 | 24.12 | 9.7 |
| Charlotte, NC Airport | 1.62 | 16.54 | 3.9 |
| Columbia Metro Airport | 0.96 | 17.14 | 4.6 |
| Orangeburg Airport | 1.26 | 14.00 | 0.5 |
| Augusta, GA Airport | 2.57 | 19.79 | 5.9 |
| Florence Airport | 0.48 | 14.81 | 3.7 |
| North Myrtle Beach Airport | 1.24 | 14.90 | 1.9 |
| Charleston Air Force Base | 4.64 | 15.01 | 2.8 |
| Savannah, GA Airport | 3.80 | 15.87 | 3.6 |
| *Weekly precipitation totals ending midnight Sunday. M - denotes total with missing values. |
4-inch depth soil temperature: Clinton: 59 degrees. Columbia: 64 degrees. Barnwell: 59 degrees. Mullins: 51 degrees.
In addition to the tornadoes produced during the strong storm system at the beginning of the period, the showers and thunderstorms produced heavy rain in the Upstate and portions of the Lowcountry. Lower rainfall totals were reported in the Central Savannah River Area and Midlands, with many stations reporting half an inch to an inch and a half. Streamflow levels remained normal due to the multiple weeks of rain that fell during the previous periods. After the initial surge in river heights due to the added rainfall in the basins, most of the river gauges dropped back out of flood stage. Only a few gauges along portions of the Santee and Savannah rivers near the coast were at major and minor flood stage.
