An upper level disturbance and surface trough contributed to a band of scattered thunderstorms developing and moving through the region in the evening, some of which reached severe limits.
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Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS CAE wrote it up.
An upper level disturbance and surface trough contributed to a band of scattered thunderstorms developing and moving through the region in the evening, some of which reached severe limits.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Columbia, SC wrote its last area forecast discussion before the first event at Aug 8, 1:44 PM EST, 2 hours 55 minutes earlier.
Area Forecast Discussion National Weather Service Columbia SC 244 PM EDT Wed Aug 8 2018 .SYNOPSIS... An upper ridge will extend westward from the Atlantic into our region through Thursday. This will allow a return to more typical summerlike weather with scattered mainly afternoon and evening thunderstorms, along with a warming trend. The upper ridge will gradually weaken late this week into this weekend as an upper trough digs into the eastern US. && .NEAR TERM /THROUGH TONIGHT/... This Afternoon: Isolated to scattered thunderstorms expected with only weak surface forcing present in the form of a lee- side trough. Potential instability will be strong today with MLCAPE values around 3000 J/kg and SB LI values around -8. The RAP may be over doing the instability, suggesting 500mb temps of -9 C to -10 C while ACARS soundings indicate values only around -8 C. Otherwise, convection allowing models are in good agreement with isolated to scattered coverage and strong instability. Highs will be in the mid 90s today with overnight lows in the low to mid 70s. This Evening and Tonight: Convective coverage may increase this evening as an upper-level shortwave pushes into the Southern Appalachians. Outflow from convection developing along the higher terrain and in the SC Upstate may trigger thunderstorms which push into the western forecast area this evening. Storms should diminish late this evening and overnight with the upper disturbance remaining to our west. Severe Potential: Steep lapse rates and a deep inverted V sounding support the potential for isolated downburst winds in pulse-type thunderstorms. Although, deep moisture over the Southeast will limit evaporative cooling and keep DCAPE values around or less than 800 J/kg. It seems reasonable that there will be a few strong to severe storms this afternoon and evening. PWAT values around 2.0 inches suggest high rain rates and localized flash flooding will also be possible. Mean wind speeds around 10 kts should promote some storm motion and generally limit the threat to flood-prone areas. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... An upper level trough will amplify over the eastern half of the country through Friday night. Short wave energy move through the trough will affect the area mainly on Thursday. At the surface, a lee side trough will linger over the Carolinas. The airmass will remain moist and unstable. Scattered showers and storms will continue each day. Have indicated pops in the 30 to 40 percent range. The threat of locally heavy rainfall along with a few strong wind gusts will continue. High temperatures both day will range from the low to mid 90s with overnight lows in the lower 70s. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... Models remain consistent with deepening the trough over the east coast this weekend. By Sunday, an upper low will close off across the lower Great Lakes/Ohio Valley region producing a deep southerly flow across the region. A slow moving cold front will move into the area this weekend and exit late Tuesday. We can expect an increased chance for showers and storms Saturday through Tuesday. Drier air looks to arrive Tuesday night into Wednesday. High temperatures will be in the upper 80s and lower 90s with lows in the low 70s. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... VFR conditions generally expected through the TAF period. Isolated to widely scattered thunderstorms are expected this afternoon with only weak surface forcing present. Therefore kept mention of t-storms out of TAFs due to low probability. However t-storm coverage may increase this evening to our west as new storms trigger along the outflow of upstream convection. Any storms in the area should dissipate late this evening and overnight. Expect WSW around 7 to 10 knots this afternoon. Cannot rule out patchy fog/stratus early Thursday morning at AGS/OGB, but a 20 knot low level jet should help suppress development. Winds will pick up out of the WSW Thursday morning with speeds around 10 kts through the afternoon. Scattered thunderstorms are expected to develop and may bring restrictions at times. EXTENDED AVIATION OUTLOOK...Scattered diurnal convection expected during the extended period. Restrictions from stratus and fog will also be possible during early morning hours. && .CAE WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. &&
Hazardous Weather Outlook National Weather Service Columbia SC 344 AM EDT Wed Aug 8 2018 GAZ040-063>065-077-SCZ015-016-018-020>022-025>031-035>038-041-090745- Lincoln-McDuffie-Columbia-Richmond-Burke-Lancaster-Chesterfield- McCormick-Newberry-Fairfield-Kershaw-Edgefield-Saluda-Lexington- Richland-Lee-Aiken-Sumter-Barnwell-Orangeburg-Calhoun-Clarendon- Bamberg- 344 AM EDT Wed Aug 8 2018 This Hazardous Weather Outlook is for the Midlands of South Carolina and the Central Savannah River area of Georgia. .DAY ONE...Today and Tonight. Showers and thunderstorms are expected to develop once again this afternoon. Stronger storms will be capable of heavy rainfall, along with periods of strong gusty winds. .DAYS TWO THROUGH SEVEN...Thursday through Tuesday. No hazardous weather is expected at this time. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time.
Special Weather Statement
National Weather Service Columbia SC
519 PM EDT WED AUG 8 2018
SCZ016-082145-
Chesterfield SC-
519 PM EDT WED AUG 8 2018
...Strong Thunderstorms Will Impact Portions of southeastern
Chesterfield County Until 545 PM EDT....
At 519 PM EDT...National Weather Service doppler radar indicated a
strong thunderstorm near Cheraw, moving northeast at 25 mph.
HAZARD...gusty winds 40 to 50 mph and excessive cloud to ground
lightning.
IMPACT...expect minor damage to tree limbs and blowing around of
light, unsecured objects. All outdoor activities should
cease. Move indoors immediately.
Some locations in the path of this storm include...
Cheraw and Patrick.
Move indoors immediately. Excessive cloud to ground lightning is
occurring with this storm. If you can hear thunder, you are close
enough to be struck by lightning.
LAT...LON 3460 7981 3453 7983 3453 7984 3449 7990
3450 7992 3449 7997 3450 7998 3449 8003
3449 8005 3446 8011 3464 8002 3473 7989
3468 7986 3465 7980 3462 7978
TIME...MOT...LOC 2119Z 240DEG 21KT 3461 7991
LCVThe Columbia radar (KCAE), 140 km away, was scanning. The volume nearest the first event began at 21:40 UTC.
3 thunderstorm wind, 2 hail, 1 lightning. Local standard time, as filed.
Spotter reported pea size hail along US Hwy 52 near Cheraw.
Trees down on Sunset Ave near Mayes Ave, blocking the roadway.
Tree down in roadway at the intersection of Halfacre Rd and St. Philips Church Rd.
Trees were downed in the vicinity of Mealing Rd and Martintown Rd, blocking all lanes of Mealing Rd.
Buford Fire Dept reported that lightning struck a house near the intersection of Shiloh Unity Rd and Plyler Mill Rd. The house sustained moderate damage. Time estimated.
NWS COOP observer 4 miles SW of Cassatt reported small hail along with a few small limbs down.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in South Carolina in 2018Every state in 2018This day in weather historyWarnings in South Carolina, August 2018
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 767490, 767480, 767485, 767486, 767478, 767491.