The week started with a high-pressure system centered over the western Atlantic, which provided unseasonably warm temperatures through the middle of the week. High temperatures on Monday, May 4, climbed from the mid-60s into the mid to upper 80s. A few localized areas in the Lowcountry reached the lower 90s, including 91 degrees reported at the National Weather Service (NWS) station at the Charleston International Airport.
A warm front stalled near the North and South Carolina border on Tuesday, and supercell thunderstorms with heavy rain, frequent lightning, large hail, and tornadoes trained along the boundary. The NWS Greer Office confirmed an EF1 tornado, with estimated peak winds at 100 mph, in Chester County. The tornado was on the ground for 5 miles, causing some damage to homes, but snapped and uprooted numerous trees along its path. Unfortunately, a man was struck and killed by lightning while getting out of his car in Chester County and was the first lightning fatality national for the year. The same supercell spawned another tornado, confirmed by both the NWS Greer and Columbia Offices. The tornado began near Great Falls in Chester County and was on the ground for almost 15 miles before it dissipated in Lancaster County south of Heath Springs. Based on the snapped and uprooted hardwood and softwood trees and damage to homes and vehicles, the tornado was rated an EF2, with max winds of 115 mph. The supercell also produced golf ball-sized hail along the tornado path and tennis ball-sized hail in Bethune.
The warmer than normal temperatures started to ease on Wednesday, May 6, as many locations across the state, reported high temperatures in the mid to upper 70s, only five degrees above normal. By Thursday morning, low temperatures dropped into the 40s, up to 15 degrees below normal, and daytime highs reached the upper 60s. A weak front approached the area on Friday, producing a few scattered thunderstorms and some gusty winds. The frontal passage brought a reinforcing shot of unseasonably cool, dry air into the region. High and low temperatures continued to be below normal, and frost and freeze advisories were issued across much of the Upstate as low temperatures dipped into the mid-30s. Due to the lack of rainfall and low relative humidity, there was increased fire danger across the state.
(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 | 1.20 | 28.54 | 12.3 |
| Greer Airport | 3.65 | 32.32 | 15.4 |
| Charlotte, NC Airport | 0.45 | 21.78 | 7.0 |
| Columbia Metro Airport | 0.03 | 18.50 | 4.0 |
| Orangeburg Airport | Trace | 15.45 | 0.2 |
| Augusta, GA Airport | 0.01 | 22.61 | 7.0 |
| Florence Airport | 0.64 | 17.46 | 4.5 |
| North Myrtle Beach Airport | 0.51 | 17.27 | 2.3 |
| Charleston Air Force Base | Trace | 18.46 | 4.2 |
| Savannah, GA Airport | Trace | 20.76 | 6.6 |
| *Weekly precipitation totals ending midnight Sunday. M - denotes total with missing values. |
4-inch depth soil temperature: Clinton: 60 degrees. Columbia: 67 degrees. Barnwell: 61 degrees. Mullins: 58 degrees.
Much of the rain that fell occurred during the middle of the week as a strong cold front pushed through the state. Rainfall totals ranged from close to four inches in portions of the Upstate, to one to two inches in the Midlands, to lower amounts (0.10 to 0.33 inches) in the Lowcountry. With some of the heaviest rain falling in the headwaters of the river basins, some river gauges along portions of the Pee Dee, Santee, and Savannah rivers were at an action or minor flood stage.
The rainfall helped keep streamflow values across much of the state near normal due to the multiple weeks of rain that fell during the previous periods. However, the lack of general rainfall across the Pee Dee Basin caused lower than normal streamflow values along some rivers in that basin, including the Little Pee River near Galivants Ferry.
