WEEKLY SOUTH CAROLINA WEATHER 2018
August 20, 2018 - August 26, 2018
It was another fairly quiet weather week, starting off with a moist, southwest flow around the west side of high pressure in the Atlantic and a cold front approaching the state from the northwest. Overnight storms on Sunday, August 19, into Monday, August 20, produced localized rainfall totals up to 3 inches in Beaufort and Jasper counties. High temperatures across the entire state ranged from the mid-80's to mid-90's on August 20, with the National Weather Service station in Charleston reporting a maximum temperature of 93 degrees. A stalled surface front over southern North Carolina focused the development of showers and thunderstorms in portions of the Piedmont and northern Midlands during the late afternoon on Monday. The event produced over an inch of rain in localized areas. The CoCoRaHS Station at York 6.3 E measured 1.26 inches, while the NWS station in Catawba recorded 0.91 inches.
A cold front started to push through the Upstate on Tuesday, August 21, and a pre-frontal trough formed along the South Carolina and North Carolina border. This atmospheric set-up led to the development of heavy rain, especially in the northern Piedmont, and a few thunderstorms caused downed trees both in Starr and Anderson (Anderson County). All of the substantial rain in the Upstate and Piedmont during the week occurred from this system. The CoCoRaHS station at Mountville 1.6 SE reported a total for the week of 2.64 inches, with 2.61 inches from the 24-hour period ending on the morning of August 22. During the morning of August 22, dense fog was reported in the Upstate and southern Piedmont. The Greenville-Spartanburg Airport recorded visibilities reduced to 0.5 miles, and the Greenwood Airport had visibilities to less than a mile. The front continued to push toward the coast on Wednesday, and high pressure began to spread over the region, bringing a dry air mass and low humidity to portions of the state.
By Thursday, August 23, the cold front had moved offshore and become stationary over the Atlantic. With the wind shift from the southwest to more northerly winds, dewpoints began to drop into the upper 50's, and at most locations, high temperatures for the day were below normal under mainly clear skies. The high temperature of 81 degrees at Walhalla was 7 degrees below normal, and the maximum temperature of 83 degrees at Summerville was 5 degrees below normal for this time of year. On the morning of Friday, August 24, many NWS stations reported low temperatures in the lower to mid-50's. The NWS station at Little Mountain recorded a minimum temperature of 54 degrees, which is the lowest minimum temperatures at the location since May 7 and broke the previous record low temperature of 55 degrees at the station set back in 1930. The 59 degrees at the Greer-Spartanburg Airport also broke the record low temperature of 60 degrees from 1969. The drier air mass and cooler temperatures made it feel more like mid-September than the last full week of August. The NOAA Ocean Service gauge in Charleston Harbor reported an astronomical high tide value of 7.14 feet MLLW around 8:00 p.m. at high tide and minor saltwater flooding was observed in low-lying areas of the city.
Some reporting stations in the Lowcountry and Pee Dee awoke on Saturday, August 25, to temperatures in the mid-60's, atypical for this time of year. The NWS station in Hartsville in Darlington County reported a minimum temperature of 63 degrees, which is the fourth coldest August 25 on record at the station, which has been collecting observations since 1947. A round of localized heavy rains overnight on August 25 and into August 26 in Beaufort County caused up to 4 inches of rain in Bluffton and Forest Beach, while the NWS stations in Bamberg, Orangeburg, Horry, Sumter, Darlington and Dillon counties, along with other portions of in the south Midlands and Pee Dee regions, reported no rain during the 7-day period.
(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 temperature reported was 97 degrees at the Orangeburg 2 station in Orangeburg County on August 26.
The lowest temperature reported was 51 degrees at Ninety-Nine Islands in Cherokee County on August 24.
The maximum 24-hour precipitation reported was 2.20 inches at the National Weather Service Cooperative Weather Station in Jocassee 8 NWN in Oconee County ending at 8:30 a.m. on August 20.
The CoCoRaHS Station Bluffton 2.9 ENE (SC-BF-22) reported a 24-hour precipitation total of 2.81 inches, ending at 8:00 a.m. on August 20.
The state average precipitation for the seven-day period was 0.20 inches.
| ||Weekly*||Since Jan 1||Departure
|Charlotte, NC Airport||0.07||29.33||1.2
|Columbia Metro Airport||Trace||23.24||-8.1
|Augusta, GA Airport||0.36||31.15||0.8
|North Myrtle Beach Airport||0.14||37.77||3.4
|Charleston Air Force Base||0.04||37.82||3.2
|Savannah, GA Airport||0.25||26.32||-7.3
| *Weekly precipitation totals ending midnight Sunday.
| + Missing precipitation from previous week added into total.
4-inch depth soil temperature: Clinton: NA. Columbia: 81 degrees. Barnwell: 75 degrees. Mullins: 74 degrees.
During the week of August 20-26, the only areas to receive measurable rainfall were in Beaufort and Jasper counties in the Lowcountry and portions of the Piedmont and Upstate. Most of the rainfall that fell across the state this week was less than 1.00”, with higher amounts in localized areas. Another week with a lack of rainfall elsewhere across the state led to a continued drop off in streamflow values in some of the area creeks and rivers; especially in the upper Pee Dee region. The Lynches River near Bishopville is reporting streamflow of 95.8 cubic feet per second (CFS), below the minimum flow of 109 CFS in 2002. Other rivers across the state, such as the Saluda River near Ware Shoals and the South Fork of the Edisto River near Denmark, are now reporting below normal streamflow values. Only a few rivers across the state, like the Pee Dee River at Pee Dee and Santee River near Pineville, were reporting slightly above normal stream flows going into the week of August 27.
COASTAL OCEAN TEMPERATURES:
Charleston Harbor (CHTS1): 84.0 degrees.
Capers Nearshore Buoy (Station 41029): 80.8 degrees.
Fripps Nearshore Buoy (Station 41033): 82.6 degrees.