An upper trough, sufficient moisture, diurnal heating, and atmospheric shear led to severe thunderstorm development.
Every event with a place to put it. Tap one for its entry below.
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 trough, sufficient moisture, diurnal heating, and atmospheric shear led to severe thunderstorm development.
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 May 3, 1:23 PM EST, 1 hour 17 minutes earlier.
Area Forecast Discussion National Weather Service Columbia SC 223 PM EDT Mon May 3 2021 .SYNOPSIS... Severe thunderstorms are possible this afternoon. An upper trough will move eastward from the Mississippi Valley on Tuesday bringing another potentially active day of weather before a cold front crosses the region on Wednesday. Drier and cooler weather expected for the end of the week into the weekend. && .NEAR TERM /THROUGH TONIGHT/... Tornado Watch in effect until 7 pm. Upper trough will move across the Ohio Valley through tonight. Surface high pressure well off the coast with a low pressure system crossing the Mississippi Valley. Our area remains in the warn sector. Deep, moist SW flow with embedded weak shortwaves support moderate destabilization with surface based CAPE 1000 to 2000 J/kg. Deep convergence moving into the Midlands early this afternoon. PWATs around 1.7 inches. Showers and thunderstorms west of the area at 2 pm expected to move east into the CSRA and Midlands through this evening. Severe potential include damaging wind gusts, large hail, isolated tornadoes and locally heavy rainfall. The shortwave will move out of the region after sunset, leading to decreasing activity during the evening. Any lingering convection should dissipate around midnight as the airmass becomes less unstable. Overnight, a moderate low level jet will develop and generally hinder fog development despite abundant low level moisture. Lows will be above normal, once again in the mid 60s to around 70 degrees. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... Ridge will have strengthened over the area by Tuesday morning with a lull expected in shower and convective activity, although with PWATs remaining around 1.5 inches or greater, still can't rule out some showers across the area. Deeper trough will approach from the west and strengthening surface front moving into the area Tuesday afternoon which will generate strong to severe storms to the west of the area with the flow pushing these storms east. While shear may be a bit weaker tomorrow afternoon, instability will be similar so still expect storms to move into the area and may actually be higher in coverage than we saw today with better forcing. Severe weather threat remains low with a marginal risk in place from SPC mainly for isolated damaging wind gusts. Temperatures will climb to above normal with SW winds and warm advection while dew points will make conditions feel somewhat stifling once again. CAMs favor somewhat linear convection to develop along the strong forcing which should push through the area overnight with increasing low level jet keeping at least some instability and allowing storms to continue. Cut back pops a bit for Wednesday with drier air likely to move in at some point during the day with EC ensembles trending a bit drier but still seeing the potential for the front to stall out and some convection develop along it but with drier air moving in aloft, QPF amounts are likely to be low. A bit more sun Wednesday should also keep highs in the low to mid 80s. Cold advection will increase Wednesday night with lows dropping into the 50s. && .LONG TERM /THURSDAY THROUGH MONDAY/... Drier long term period expected with high pressure moving in and cooler conditions into the end of the week. A more amplified trough will push into the area late Thursday into Friday which will likely develop a coastal low although there is uncertainty as to how far into the Atlantic this would be and so pops will remain low and only in the far north and east forecast areas. Cooler high pressure with lower 500mb heights into the weekend before the surface high slowly moves offshore and we will start to see moderating temperatures and a ridge building over the region once again. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... Scattered to numerous showers and thunderstorms to affect the TAF sites through this evening. Some thunderstorms may produce strong wind gusts or hail. Isolated tornadoes also possible. Should see convection diminish or move east of the area early this evening. Have indicated tempo for tstms 19z-23z. Outside of convection, mainly VFR with southwest winds 10-12 kts with gusts around 20 kts. Winds are expected to stay up overnight with a moderate nocturnal jet developing. Mixing should generally prevent fog development tonight. However low level moisture will remain high and ceiling restrictions can't be ruled out near the end of the TAF period. EXTENDED AVIATION OUTLOOK...Restrictions possible in showers and thunderstorms through Wednesday as an unsettled weather pattern crosses the region. && .CAE WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. &&
Hazardous Weather Outlook National Weather Service Columbia SC 129 PM EDT Mon May 3 2021 GAZ040-063>065-SCZ016-018-020>022-025>031-035-037-038-041-115-116- 135>137-041730- Lincoln-McDuffie-Columbia-Richmond-Chesterfield-McCormick-Newberry- Fairfield-Kershaw-Edgefield-Saluda-Lexington-Richland-Lee-Aiken- Sumter-Barnwell-Calhoun-Clarendon-Bamberg-Northern Lancaster- Southern Lancaster-Northwestern Orangeburg-Central Orangeburg- Southeastern Orangeburg- 129 PM EDT Mon May 3 2021 ...TORNADO WATCH 129 IN EFFECT UNTIL 7 PM EDT THIS EVENING... This Hazardous Weather Outlook is for the Midlands of South Carolina and the Central Savannah River area of Georgia. .DAY ONE...This afternoon and tonight. Please listen to NOAA Weather Radio or go to weather.gov on the Internet for more information about the following hazards. Tornado Watch. .DAYS TWO THROUGH SEVEN...Tuesday through Sunday. Strong to severe thunderstorms possible again on Tuesday and Wednesday with damaging wind gusts and large hail as the primary threats. .SPOTTER INFORMATION STATEMENT... Spotter activation will likely be needed. GAZ077-041730- Burke- 129 PM EDT Mon May 3 2021 This Hazardous Weather Outlook is for the Midlands of South Carolina and the Central Savannah River area of Georgia. .DAY ONE...This afternoon and tonight. Strong to severe thunderstorms will be possible this afternoon with damaging wind gusts and large hail as the primary threats. .DAYS TWO THROUGH SEVEN...Tuesday through Sunday. Strong to severe thunderstorms possible again on Tuesday and Wednesday with damaging wind gusts and large hail as the primary threats. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time.
Special Weather Statement
National Weather Service Columbia SC
235 PM EDT Mon May 3 2021
GAZ040-SCZ018-031900-
Lincoln GA-McCormick SC-
235 PM EDT Mon May 3 2021
...Strong Thunderstorms Will Impact Portions of northwestern Lincoln
and northwestern McCormick Counties Until 300 PM EDT....
...Boaters on Lake Strom Thurmond Should Seek Safe Harbor...
At 234 PM EDT...National Weather Service doppler radar indicated a
strong thunderstorm over Calhoun Falls, or 14 miles southwest of
Abbeville, moving northeast at 45 mph.
HAZARD...gusty winds 40 to 50 mph.
IMPACT...expect minor damage to tree limbs and blowing around of
light, unsecured objects.
Some locations in the path of this storm include...
Lake Strom Thurmond, Bobby Brown State Park, Willington, Gill's
Point, Mount Carmel Park, Hester's Ferry Campground, Chennault, Mount
Carmel and Leroy's Ferry Recreation Area.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Boaters on Lake Strom Thurmond should move to shore and seek shelter.
Strong, erratic wind gusts and lightning are possible. If you can
hear thunder, you are close enough to be struck by lightning.
&&
LAT...LON 3398 8264 3397 8263 3398 8261 3396 8257
3402 8259 3407 8253 3407 8251 3408 8248
3406 8245 3406 8233 3402 8232 3400 8232
3387 8260 3387 8261 3398 8265
TIME...MOT...LOC 1834Z 246DEG 40KT 3410 8260
CRLThe Columbia radar (KCAE), 72 km away, was scanning. The volume nearest the first event began at 19:41 UTC.
13 thunderstorm wind, 9 hail. Local standard time, as filed.
Newberry Co Sheriff's Office reported trees down near Hwy 76 and Garys Ln. Time estimated.
Newberry Co Sheriff's Office reported trees down along Hwy 56 and Brehmer Road. Time estimated.
Newberry Co Sheriff's Office reported trees down off of Hwy. 121 and Drayton St. Time estimated.
SCHP reported a tree on roadway at Pisgah Church Road and US Hwy. 1. Time estimated.
COOP Observer at Saluda Water Plant reported ping pong ball size hail. Time estimated.
Saluda Co Emergency Manager reported golf ball size hail at the Saluda Co Courthouse. Time estimated.
NWS Employee reported a tree partially snapped on Canting Way in Lexington. Time estimated.
Lexington Co Emergency Manager reported a power line down on Harmon St and Laurel St. Time estimated.
Lexington Co Emergency Manager reported a power line down at the intersection of Barr Rd and Wildlife Rd. Time estimated.
Public report, via social media, of golf ball size hail in the Red Bank area at the intersection of SC Hwy 6 (S Lake Dr) and SC Hwy 602 (Platt Springs Rd). Time estimated.
NWS Employee reported golf ball size hail in Red Bank.
Public report of golf ball size hail along Savannah Hills Dr. Time estimated.
SC DOT reported a tree down in the roadway blocking all lanes at the intersection of Horatio-Hagood Road and SC 261 near Rembert. Time estimated.
Trained spotter reported golf ball size hail in the Dunhill neighborhood off of Corley Mill Road. Time estimated.
A trained spotter reported dime to penny size hail at the intersection of I-20 and US Hwy 378. Time estimated.
Public reported pea to dime size hail on Old Barnwell Road near the Airport. Time estimated.
Reported a tree down on a vehicle with a person trapped inside.
Report received via social media of a mid sized tree that fell on a property near the Five Points area in Columbia. Time estimated.
Lee Co Emergency manager reported 3 trees down on the roadway and 1 power line down between St. Charles Rd and Dog Island Rd. Time estimated.
Trained spotter reported hail up to golf ball size in the town of Lynchburg. Time estimated.
SCHP reported a tree down along W Brewington Rd near October Cir, south of Dalzell. Time estimated.
SCDOT reported a tree that had fallen, partially blocking SC 64 near the town of Olar. Time estimated.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in South Carolina in 2021Every state in 2021This day in weather historyWarnings in South Carolina, May 2021
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: 952854, 952862, 952874, 952868, 952850, 952876, 952852, 952864, 952872, 952869, 952873, 952858, 952860, 952863, 952875, 952866, 952870, 952855, 952856, 952861, 952853, 952851.