WEEKLY SOUTH CAROLINA WEATHER 2018
July 23, 2018 - July 29, 2018
A stagnant weather pattern dominated the weather during most of the week, with high-pressure in the West and a broad upper-level trough across the Eastern United States. This set up a nearly stationary front draped across the Carolinas, from central North Carolina into the South Carolina Midlands and the formation of small surface troughs and low-pressure systems along the stalled boundary.
Early on Monday, July 23, a 40-mph wind gust from a thunderstorm was measured by a coastal station in Murrell's Inlet. Later that afternoon, a waterspout formed offshore from Myrtle Beach and moved onshore near the 900 Block of Ocean Avenue. The tornado was about 15 yards wide and moved onshore for about 1,000 yards before dissipating. While there was no structural damage, beach chairs and umbrellas were tossed into the area. The National Weather Service (NWS) in Wilmington rated it an EF0, with wind gusts up to 65 mph. Afternoon thunderstorms caused pea-sized hail (0.25 inch) in Irmo in Richland County and pea- to quarter-sized hail (0.25 to 1.00 inch) in Red Bank in Lexington County. Quarter-sized hail (1.00 inch) and downed trees were reported near Fort Jackson, and a nearby RWINDS station at Horrell Hill recorded a 56-mph wind gust. Columbia Metro picked up 0.98 inches of rain, which was almost double the amount of rainfall it had received since the beginning of the month (0.51 inches).
During the late evening hours on Monday and into the early morning of July 24, many National Weather Service NWS and CoCoRaHS stations in Berkeley, Charleston, and Dorchester counties reported rainfall totals between 3 and 4 inches and standing water up to a foot deep in some low-lying areas was reported in Moncks Corner. A weather station in Briarcliff Acres (Horry County) observed a 51-mph wind gust at 3:30 a.m. Tuesday morning. There were multiple social media reports of waterspouts offshore of Hunting Island and Hutchinson Island. The NWS Station in Ninety-Nine Islands reported a new record low maximum temperature of 78 degrees on the 24th. The weather pattern persisted, and on the afternoon of Wednesday, July 25, a CoCoRaHS observer at Gaffney 5.9 WNW (SC-CK-17) measured nearly 2 inches of rain that fell in an hour, and the CoCoRaHS station at Daufuskie Island 1.7 SW in Beaufort County (SC-BF-23) reported 3.20 inches in 90 minutes. Strong thunderstorms in the Midlands produced strong winds and storm damage in the Dentsville area of Richland County, near Camden in Kershaw County, and multiple locations across Lexington County.
A cold front moved through the Upstate on July 26, bringing somewhat drier air into the area with limited shower activity, mainly in the afternoon as it became a stationary boundary across the Midlands. This pattern set up a somewhat typical summer pattern with thunderstorms initiating along the sea breeze front. Thunderstorms produced dime-sized (0.75 inches) to quarter-sized (1.00 inch) hail in Mount Pleasant, while heavy rains in Hardeeville in Jasper County and College Park in Berkeley County caused flooding on low-lying roads. The drier air in the Upstate led to stations reporting minimum temperatures in the mid-60’s, two to four degrees below normal, on the morning of Friday, July 27. By the end of the week, the state was positioned on the western side of a high-pressure over the Atlantic and on the eastern edge of a broad trough of low pressure in the Great Lakes. The southerly flow and increased moisture caused another day of scattered thunderstorms beginning near the coast along the developing sea breeze, followed by thunderstorms developing in further inland locations during the afternoon. A strong thunderstorm caused trees to fall on power lines near Minturn, knocking out power to portions of Marlboro County.
A low-pressure surface trough across the state helped scattered thunderstorms form across portions of the Lowcountry, Midlands, and Pee Dee regions on Saturday, July 28 and Sunday, July 29. Very heavy and localized rains impacted Florence starting late in the evening on July 28. The Florence Airport reported a total of 3.74 inches from the event, and the following morning, the CoCoRaHS station Florence 2.1 SW (SC-FL-13) reported a 24-hour rainfall total of 7.60 inches. The rains caused Black Creek near Quinby to rise 3 feet over a period of 7 hours. Multiple reports were made via social media of a waterspout south of Folly Beach the morning of July 29. Training thunderstorms produced heavy rains across portions of the Midlands during the afternoon. A NWS employee reported 3.82 inches of rain in 90 minutes in Lexington County. Along the coast, heavy rains in Charleston caused the closure of some downtown streets due to flooding, and nearly 3.50 inches of rain were reported in McClellanville.
(Note: The highest and lowest official temperatures and highest precipitation totals provided below are based on observations from the National Weather Service Cooperative Observer network and the National Weather Service's Forecast Offices.)
The highest official temperature reported was 97 degrees at Wateree Dam in Kershaw County on July 27.
The lowest official temperature reported was 56 degrees at Jocassee in Oconee County July 27.
The heaviest official 24-hour precipitation reported was 3.36 inches at the National Weather Service Cooperative station at the Georgetown County Airport ending at midnight on July 26.
The state average precipitation for the seven-day period was 2.40 inches.
Florence Regional Airport had three days with more than 1.00 inch of rain during the week, with a total of 5.54 inches over the 7-day period.
| ||Weekly*||Since Jan 1||Departure
|Charlotte, NC Airport||1.90||24.84||0.7
|Columbia Metro Airport||3.12||19.94||-6.3
|Augusta, GA Airport||0.98||26.74||0.5
|North Myrtle Beach Airport||2.78||32.52||5.0
|Charleston Air Force Base||2.72||32.55||4.5
|Savannah, GA Airport||1.49||22.56||-4.8
| *Weekly precipitation totals ending midnight Sunday. |
4-inch depth soil temperature: Clinton: 77 degrees. Columbia: 80 degrees. Barnwell: 75 degrees. Mullins: 71 degrees.
River levels improved in some locations of the north Midlands and Pee Dee regions, such as the Edisto River near Orangeburg. Black Creek at Hartsville and the Little Pee Dee near Galivants Ferry reported below normal streamflow, despite rainfall in the region. Above normal rainfall in the Lowcountry and along the coast has the stream flows in some area rivers higher than normal, but below flood stage at the time of this report.
COASTAL OCEAN TEMPERATURES:
Charleston Harbor (CHTS1): 84.9 degrees.
Capers Nearshore Buoy (Station 41029): 82.9 degrees.
Fripps Nearshore Buoy (Station 41033): 84.7 degrees.