On Monday, June 9, showers and thunderstorms developed as an upper-level disturbance sent a cold front slowly toward the region. Severe thunderstorms produced wind gusts up to 50 mph in the Lowcountry and Midlands, with wind damage reported in several counties. A survey team from the National Weather Service Columbia office confirmed an EF1, with estimated peak winds of 95 mph, that touched down near Chapin and was on the ground for about six miles before lifting near the Lexington-Richland County line. As the front gradually moved through the state on Tuesday, additional strong to severe storms were reported, especially in the Lowcountry. The Marine Corps Air Station in Beaufort County recorded a 46-mph wind gust, and there were reports of minor wind damage in Charleston, Colleton, Hampton, and Jasper counties. With ample cloud cover and rain, maximum temperatures were up to ten degrees cooler in some locations across the state, with highs in the low to mid-80s.
The unsettled weather pattern continued on Wednesday, triggered by a stalled frontal boundary over the state that dissipated throughout the day. Strong thunderstorms moved through portions of the Midlands and Coastal Plain, producing heavy rain and strong winds. Minor wind damage was reported in Aiken, Lexington, and Marion counties. Hail, ranging between pea and quarter-sized, was reported in Moncks Corner in Berkeley County, and two houses were struck by lightning near Sangaree.
Warm and humid conditions continued throughout the period, allowing for typical summertime diurnally driven showers, thunderstorms, and heat indices to approach 100 degrees in the Midlands and Pee Dee. Training thunderstorms on Friday prompted a flash flood warning in parts of Richland and Sumter counties, with rain rates up to two inches per hour produced by some storms. Multiple cars were stuck in flood waters around Oakland and Dalzell in Sumter County, and parts of downtown Columbia in Richland County. The USGS gauge on Rocky Branch Creek in Columbia crested at 9.76 ft. Two CoCoRaHS observers in Sumter County recorded 24-hour rainfall totals over six inches ending on Saturday morning. The active weather continued on Saturday, with showers and thunderstorms producing between one and two inches of rain in the Charleston area. This caused freshwater flooding on some of the low-lying roads.
(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 | 1.84 | 19.86 | -1.9 |
| Greer Airport | 1.29 | 23.66 | 1.1 |
| Charlotte, NC Airport | 1.57 | 18.10 | -1.8 |
| Columbia Metro Airport | 2.73 | 22.66 | 3.4 |
| Orangeburg 2 (COOP) | 2.07M | 24.90M | 3.2M |
| Augusta, GA Airport | 2.54 | 22.82 | 2.9 |
| Florence Airport | 1.90 | 17.30 | -0.9 |
| North Myrtle Beach Airport | 2.08 | 15.74 | -1.7 | Charleston Air Force Base | 2.50 | 16.61 | -2.8 |
| Savannah, GA Airport | 2.41 | 20.79 | 1.0 |
| *Weekly precipitation totals ending midnight Sunday. M - denotes total with missing values. s - denotes total with suspect data. |
4-inch depth soil temperature: Columbia: 77 degrees. Barnwell: 73 degrees. Mullins: 71 degrees.
Most of the state received at least half an inch of rain during this period. However, areas in the Charlotte Metropolitan Area and along the Interstate 85 corridor in Anderson, Oconee, Pickens, and Greenville recorded slightly less than half an inch. Rainfall totals between 1.50 and 2.00 inches were observed south and east of the Interstate 20 corridor, with locally higher amounts. Heavy rain fell across the Midlands on Wednesday afternoon, and one CoCoRaHS observer in Calhoun County recorded 1.34 inches of rain in just one hour. Slow-moving thunderstorms on Friday produced heavy rainfall across parts of Calhoun, Lexington, Richland, and Sumter counties. CoCoRaHS observers near Oakland in Sumter County recorded over 6.00 inches of rain from the event.
The U.S. Drought Monitor map, released on Thursday, June 12, indicated improvements in the region facing abnormally dry (D0) conditions in parts of Pee Dee, as D0 conditions were removed from Florence, Marion, and Williamsburg counties. Areas in Horry County under moderate drought (D1) conditions improved by one category to abnormally dry (D0) conditions, and sections of Horry County classified as D0 the previous week were taken off the map. Additionally, there was a one-category improvement in D0 and D1 conditions in Charleston and Georgetown counties.
Rain over the past few periods helped keep the 14-day average streamflow values at normal to above-normal levels. The additional precipitation during this period caused water levels at most river gauges to rise. The North Fork Edisto River at Orangeburg, the Edisto River near Givhans Ferry, and the Little Pee Dee River near Galivants Ferry approached action stage, and the Savannah River near Clyo River rose into minor flood stage by the end of the period. Tidal gauges reported values that were below the action stage during the period.
