Warm and moist conditions between high pressure extending from the Atlantic and a Lee trough positioned inland led to thunderstorms developing upstream of the area before activity shifted over Southeast South Carolina during mid to late afternoon hours.
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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 CHS wrote it up.
Warm and moist conditions between high pressure extending from the Atlantic and a Lee trough positioned inland led to thunderstorms developing upstream of the area before activity shifted over Southeast South Carolina during mid to late afternoon hours.
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 Charleston, SC wrote its last area forecast discussion before the first event at Aug 6, 2:52 PM EST, 28 minutes earlier.
Area Forecast Discussion National Weather Service Charleston SC 352 PM EDT Mon Aug 6 2018 .SYNOPSIS... Atlantic high pressure will continue over or near the area through the middle of the week, as a lee side trough persists inland. A cold front could approach the area from the northwest late in the week. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... This Evening and Tonight: A mid/upper lvl ridge of high pressure centered over the Southeast United States will gradually slide west and weaken through tonight. At the sfc, high pressure will extend from the Atlantic while a lee trough persists inland. A slight chance to chance of showers and thunderstorms will persist over much of the area into at least evening hours, with the bulk of activity occurring well inland where convection developed within the lee trough and is currently drifting toward western most zones. Ahead of these thunderstorms, the atmosphere is quite unstable with SBCAPE near 4000 J/kg and PWATs near 2.0 inches. This is combination with DCAPES near 800-1000 J/kg suggests thunderstorms being capable of brief heavy rainfall and strong wind gusts, especially over inland areas of Southeast South Carolina and Southeast Georgia into the evening. Given a lack of shear, expect a downward trend in shower/thunderstorm activity late evening into early tonight due to the loss of diurnal heating. Most areas should be dry within a couple hours of sunset. Overnight, the mid/upper level high will continue to drift west while a h5 shortwave attempts to shift over northern areas late. Although this shortwave could spawn a few showers over northern areas later tonight, increasing cloud coverage appears to be the most likely result. For this reason, low temps could be a degree or two warmer overnight. In general, lows should dip into the low/mid 70s inland to upper 70s near the coast. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/... Atlantic high pressure and a lee side trough will will persist through Wednesday before a cold front replaces the trough moves across northwestern SC Thursday. Plentiful moisture and mesoscale boundaries such as the sea breeze will support scattered showers and thunderstorms in the afternoon and evening. Some storms could become severe and locally heavy rain could lead to at least minor flooding given the slow storm motions. Temperatures are likely to be near normal Tuesday and then above normal thereafter. Heat indices could reach near 105 degrees inland Wednesday and Thursday, but likely staying below Advisory levels (110 degrees). && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... The area will be located between H5 ridging to the south and east and a trough digging into the Mississippi Valley through the weekend. At the surface, a cold front crossing the Mid-Atlantic looks to get hung up north of the area late in the week, keeping us entrenched within a sector of warm and moist west to southwesterly flow through the period. Overall, near normal storm chances have been maintained in the forecast, with the caveat that if the trough to our west approaches close enough to induce height falls aloft locally, we could enter a more active period over the weekend or early next week. Temps will generally be seasonable. && .AVIATION /20Z MONDAY THROUGH SATURDAY/... VFR conditions will prevail at both CHS and SAV terminals through 18Z Tuesday. However, temporary flight restrictions are possible at either terminal this afternoon with showers and/or thunderstorms. VCTS remains at both terminals between 19Z and 2330Z this afternoon and evening. Extended Aviation Outlook: Brief restrictions from mainly afternoon showers/thunderstorms. && .MARINE... Tonight: High pressure will remain the dominant weather feature over the coastal waters. Winds will primarily be south early around 10 kt or less, then become more south/southwest after midnight. Seas will remain between 1-2 ft, highest beyond 10 nm from the coast. Tuesday through Saturday: The local waters will remain between Atlantic high pressure to the east and low pressure to the west through the week. This pattern means mostly south/southwest winds generally 15 knots or less. Wave heights should stay 3 feet or less. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. MARINE...None. && NEAR TERM...DPB SHORT TERM...RJB LONG TERM... AVIATION...DPB/RJB MARINE...DPB/RJB
Hazardous Weather Outlook National Weather Service Charleston SC 339 AM EDT Mon Aug 6 2018 AMZ330-350-352-354-374-GAZ087-088-099>101-114>119-137>141-SCZ040- 042>045-047>052-070745- Charleston Harbor- Waters from South Santee River to Edisto Beach SC out 20 NM- Waters from Edisto Beach SC to Savannah GA out 20 NM- Waters from Savannah GA to Altamaha Sound GA out 20 NM, including Grays Reef National Marine Sanctuary- Waters from Savannah GA to Altamaha Sound GA extending from 20 to 60 NM-Jenkins-Screven-Candler-Bulloch-Effingham-Tattnall-Evans- Inland Bryan-Coastal Bryan-Inland Chatham-Coastal Chatham-Long- Inland Liberty-Coastal Liberty-Inland McIntosh-Coastal McIntosh- Allendale-Hampton-Inland Colleton-Dorchester-Inland Berkeley- Inland Jasper-Beaufort-Coastal Colleton-Charleston-Coastal Jasper- Tidal Berkeley- 339 AM EDT Mon Aug 6 2018 This Hazardous Weather Outlook is for Atlantic coastal waters, southeast Georgia and southeast South Carolina. .DAY ONE...Today and tonight. The probability for widespread hazardous weather is low. .DAYS TWO THROUGH SEVEN...Tuesday through Sunday. The probability for widespread hazardous weather is low. .SPOTTER INFORMATION STATEMENT... Spotter assistance is not anticipated at this time.
The Charleston,SC radar (KCLX), 47 km away, was scanning. The volume nearest the first event began at 20:17 UTC.
12 thunderstorm wind, 1 lightning. Local standard time, as filed.
The Allendale 911 Call Center reported a tree down on a power line along Highway 278.
The Allendale County 911 Call Center reported a tree down near Fairfax.
The South Carolina Highway Patrol reported a tree down along Williams Street.
The South Carolina Highway Patrol reported a tree down at Old Salkehatchie Highway and Cope Creek Road.
The South Carolina Highway Patrol reported a tree down on Bamberg Highway before Old Salkehatchie Highway.
The Hampton County 911 Call Center reported trees and power lines down on Lento Road near the intersection with Speed Limit Road.
The South Carolina Highway Patrol reported a tree down on Cypress Branch Road near the intersection with Gillison Branch road.
The South Carolina Highway Patrol reported a tree down on Old Salkehatchie Highway between Ram Horn Road and Anna Laurel Road.
The South Carolina Highway Patrol reported a tree down near the intersection of Black Creek Road and Highway 21.
Law enforcement reported a tree down on Highway 61 near Interstate 95.
The South Carolina Highway Patrol reported a tree down along Interstate 95 between mile marker 40 and 42.
The South Carolina Highway Patrol reported a tree down on Beech Hill Road near Mossy Rock Crossing.
The media relayed a report of a double-wide mobile home catching fire and burning to the ground due to lightning striking the roof. The fire resulted in the death of two dogs and one cat.
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: 780391, 780392, 780393, 780394, 780395, 780396, 780397, 780398, 780399, 780400, 780401, 780402, 781121.