The main weather story for the week was unstable atmospheric conditions, which led to the development of strong to severe afternoon thunderstorms. Slightly above normal maximum and minimum temperatures dominate the period, with low temperatures in the upper 60's to mid-70's, and daytime highs reaching the upper 80's to mid-90's.
A high-pressure ridge remained offshore as a weak cold front pushed into the area late Monday, July 8. The boundary helped trigger isolated afternoon thunderstorms across parts of the northern Midlands and Pee Dee. Thunderstorms in Lancaster County produced nickel-sized hail near Elgin in the early evening and heavy rain close to midnight created standing water on roads in Newberry and Ridgeway. The National Weather Service (NWS) station in Newberry reported a 24-hour rainfall total ending Tuesday morning of 2.25 inches, and a CoCoRaHS observer recorded an amount of 2.67 inches. The front did little to change the airmass, and humid and warm conditions persisted through the middle of the week. Isolated afternoon thunderstorms developed on Tuesday and Wednesday afternoon, producing localized heavy rains. Canals choked by vegetation caused the stormwater to back up, closing the bridge and surrounding low-lying roads on Trinity Place in Berkeley County. Along the Charleston County coast, lifeguards reported strong rip currents at Folly Beach on Tuesday morning and Kiawah Island on Wednesday afternoon.
The upper-level ridge over the western Atlantic shifted to the east and allowed an upper trough to move into the region on Thursday, July 11, which drove another weak cold front toward the state. The surface trough continued to hold in the area and help with the development of showers and thunderstorms. The warm and humid air did not allow minimum temperatures to cool much overnight. The NWS station at Walhalla in Oconee County measured a low temperature of 74 degrees, tying the previous high minimum temperature record for the day set back in 2011. Early evening storms in the Upstate produced penny-sized hail (0.75 inches) in Greer and caused downed trees in the Spartanburg area. Later in the evening, strong winds with some nocturnal thunderstorms downed trees in the Gilbert and Irmo areas of Lexington County. Heading into Friday, July 12, Tropical Storm Barry began making its approach toward the Gulf Coast, and moisture from the Gulf funneled into the Southeast. When combined with the slow-moving frontal boundary approaching the region, instability increased, along with the potential for heavy rain and severe thunderstorms.
On Saturday, July 13, strong to severe thunderstorms developed across the state due to the very moist and unstable atmosphere, aided by the surface trough and stalled front just north of the area. Most of the major NWS stations located at airports across the state measured wind gusts up to 30 mph, however, stronger winds were embedded in some of the severe thunderstorms across the state. These strong winds downed trees in Charleston, Dorchester, Fairfield, Kershaw, Lancaster, Orangeburg, Richland, Spartanburg and Union counties. Powerlines were felled in Rembert, Spartanburg and Whitmire. A strong outflow boundary caused damage near Grays in Jasper County. Unfortunately, the intense storms are suspected to be the cause of a fatal boating accident on Lake Marion. The boat was heading to a landing at Lake Marion Resort when strong wind and waves associated with a nearby thunderstorm caused the boat to overturn, resulting in one fatality. Some of the observed rainfall totals from these storms were 1.98 inches at the NWS station located at the North Myrtle Beach Airport and 1.11 inches at the Clemson Oconee County Airport. Mostly cloudy skies on Sunday, July 14, gave way to sunshine by the late afternoon as slightly drier conditions began to settle into the region.
(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 | 0.92 | 24.24 | 0.4 |
| Greer Airport | 0.74 | 28.38 | 3.1 |
| Charlotte, NC Airport | 0.37 | 27.79 | 5.6 |
| Columbia Metro Airport | 0.78 | 22.26 | -1.2 |
| Orangeburg Airport | 0.17 | 15.58 | -9.7 |
| Augusta, GA Airport | 0.32 | 21.43 | -2.7 |
| Florence Airport | 2.56 | 21.04 | -1.2 |
| North Myrtle Beach Airport | 2.97 | 22.29 | -2.3 |
| Charleston Air Force Base | 2.70 | 21.07 | -3.9 |
| Savannah, GA Airport | 0.06 | 25.14 | 0.6 |
| *Weekly precipitation totals ending midnight Sunday. M - denotes total with missing values. |
4-inch depth soil temperature: Clinton: Not Available. Columbia: 82 degrees. Barnwell: 77 degrees. Mullins: 75 degrees.
Rainfall totals over the seven days were varied across the Palmetto State, with localized areas of Horry and Oconee counties observing up to five inches of rain, while locations in the Central Savannah River Area (CSRA) received less than half an inch. River and stream levels remain below critical flood thresholds through the period, though the isolated rainfall caused stream levels to continue to rise slightly. Similarly, streamflow values in areas that received the heaviest rainfall totals increased and remained slightly above normal through Sunday. Year-to-date rainfall totals in the Upstate remain near to above normal for this time of year, with more than twenty-five inches reported at many locations and over fifty inches in some of the more mountainous areas. Between twenty and thirty inches of rain have fallen since the beginning of the year in the Midlands. However, portions of the Central Savannah River Area are close to ten inches below normal since January 1. Parts of the Lowcountry and Pee Dee continue to be the driest areas of the state, with less than twenty inches of rain for the year in areas from the Interstate 95 corridor to the coast, with isolated totals of over twenty-five inches in portions of Beaufort, Charleston and Colleton counties. In areas that have missed the beneficial rainfall, the totals are six to eight inches below normal for this time of year, and portions of Horry and Marion counties close to twelve inches below normal.
