A mesoscale convective complex developed in the middle and upper northwest flow over the region. This complex moved southeast across the Northern and Central Midlands overnight.
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.
A mesoscale convective complex developed in the middle and upper northwest flow over the region. This complex moved southeast across the Northern and Central Midlands overnight. The system produced numerous reports of downed trees and large hail.
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 9, 9:13 PM EST, 3 hours 42 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE COLUMBIA SC 1013 PM EDT MON MAY 9 2011 .SYNOPSIS... A BACK DOOR COLD FRONT EXTENDING NORTHWEST TO SOUTHEAST ACROSS THE STATE WILL BECOME DIFFUSE ON TUESDAY AS HIGH PRESSURE RIDGES IN FROM THE NORTH THROUGH MID-WEEK. THE RETURN OF SOUTHERLY WINDS WILL BRING INCREASING MOISTURE TO THE REGION INTO WEDNESDAY. && .NEAR TERM /THROUGH TUESDAY/... THE LATEST RUC AND SATELLITE IMAGERY INDICATES A MID-LEVEL SHORTWAVE TROUGH WILL BE MOVING INTO THE FORECAST AREA OVERNIGHT. THIS FEATURE PLUS THE DIFFUSE NORTHWEST TO SOUTHEAST ORIENTED BOUNDARY COULD POSSIBLY SUPPORT SHOWERS OR THUNDERSTORMS. THE MAV AND MET MOS POPS WERE LESS THAN 20 PERCENT. THE SREF SHOWED POPS OF 20 TO 40 PERCENT IN THE NORTH PART. STILL BELIEVE THE CHANCE IS TOO LOW TO INCLUDE IN THE FORECAST BASED ON LIMITED MOISTURE...DIURNAL COOLING...AND CURRENT RADAR. EXPECT LOW TEMPERATURES IN THE 60 TO 65 DEGREE RANGE. && .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/... UPPER RIDGE TO THE WEST BECOMES MORE AMPLIFIED AS A DEEP TROUGH DIGS INTO THE FOUR CORNERS REGION ON TUESDAY...WHILE A CLOSED UPPER LOW REMAINS OFF THE NORTHEAST COAST. THE FORECAST AREA REMAINS IN A BAND OF HIGHER PRECIPITABLE WATER AIR TUESDAY THROUGH THURSDAY WHICH WILL ALLOW FOR THE ATMOSPHERE TO BECOME DIURNALLY UNSTABLE. MODELS INDICATE CONVECTION DEVELOPING ACROSS THE OHIO VALLEY TUESDAY AFTERNOON THEN DIVING SOUTH THROUGH THE CAROLINAS TUESDAY NIGHT INTO WEDNESDAY...SUPPORTED BY NORTHERLY CORFIDI VECTORS. SPC CONTINUES TO HAVE THE AREA IN A SLIGHT RISK OF SEVERE WEATHER GIVEN A MODERATE TO HIGHLY UNSTABLE AIR MASS THAT IS EXPECTED TO DEVELOP TUESDAY AFTERNOON INTO THE EVENING HOURS...AIDED BY SHORTWAVE ENERGY DROPPING DOWN THE BACKSIDE OF THE UPPER RIDGE. WILL INCREASE POPS TO HIGH CHANCE LATE TUESDAY AFTERNOON THROUGH THE OVERNIGHT HOURS. THE WEATHER PATTERN DOES NOT CHANGE MUCH ON WEDNESDAY WITH A SHARP UPPER RIDGE AXIS JUST WEST OF THE FORECAST AREA WITH NORTHERLY FLOW ALLOWING ANY UPPER DISTURBANCES TO TRACK SOUTH INTO THE AREA. THERE DOES NOT APPEAR TO BE A STRONG SHORTWAVE TO TRIGGER CONVECTION LIKE THERE WILL BE TUESDAY...BUT WILL NEED TO CARRY DIURNAL POPS GIVEN AN UNSTABLE AFTERNOON AIR MASS. THE UPPER RIDGE AXIS SHIFTS MORE OVER THE FORECAST AREA BY THURSDAY AND SHOULD HELP MINIMIZE AFTERNOON CONVECTION...BUT WILL KEEP THE INHERITED SLIGHT CHANCE POPS. TEMPERATURES THROUGH THE PERIOD SHOULD REMAIN ABOVE NORMAL ON TUESDAY AND WILL BE NEAR TO SLIGHTLY ABOVE NORMAL ON WED/THU. && .LONG TERM /FRIDAY THROUGH MONDAY/... LONGER RANGE GUIDANCE STILL SHOWS AN UPPER-LEVEL CLOSED LOW DEVELOPING ACROSS THE UPPER MISSISSIPPI RIVER VALLEY REGION FRIDAY...THEN SLOWLY MOVING EASTWARD AS THE MAIN UPPER-LEVEL RIDGE OFF TO THE EAST BEGINS TO WEAKEN AND FLATTEN OUT. COLD FRONT ASSOCIATED WITH THE UPPER LOW WILL MOVE THROUGH FRIDAY NIGHT INTO SATURDAY...THEN LINGER ACROSS THE REGION INTO NEXT WEEK. EXPECT TO SEE A CHANCE OF SHOWERS/STORMS FROM FRIDAY THROUGH MONDAY. TEMPERATURES IN THE MID 80S FRIDAY...THEN COOLING DOWN SLIGHTLY FOR THE REMAINDER OF THE FORECAST PERIOD BEHIND THE FRONT.TO REMAIN NEAR NORMAL THROUGH THE PERIOD. && .AVIATION /02Z TUESDAY THROUGH SATURDAY/... TAFS SHOULD REMAIN MAINLY VFR THROUGH THE PERIOD. EXCEPTION WILL BE AT KAGS/KOGB WHERE BRIEF MVFR VISIBILITIES MAY BE FOUND TOWARDS SUNRISE TUESDAY MORNING. MAIN FRONTAL BOUNDARY REMAINS OFF TO THE SOUTHWEST OF TAF SITES BUT WILL DRIFT INTO THE CSRA BY TUESDAY AFTERNOON. NOT ANTICIPATING ANY CONVECTION OVERNIGHT INTO TUESDAY MORNING...BUT SCATTERED THUNDERSTORMS MAY DEVELOP LATE TUESDAY AFTERNOON INTO THE EARLY EVENING AS UPPER LEVEL ENERGY ROTATES THROUGH THE REGION. AS A RESULT...WILL MENTION CB AT ALL TAF SITES AFTER 18Z TUESDAY. EXTENDED AVIATION OUTLOOK...SOME EARLY MORNING FOG/STRATUS POSSIBLE AS WELL AS AFTERNOON/EVENING CONVECTION POSSIBLE THROUGH THE PERIOD. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. &&
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE COLUMBIA SC 333 AM EDT MON MAY 9 2011 GAZ040-063>065-077-SCZ015-016-018-020>022-025>031-035>038-041-100745- LINCOLN-MCDUFFIE-COLUMBIA-RICHMOND-BURKE-LANCASTER-CHESTERFIELD- MCCORMICK-NEWBERRY-FAIRFIELD-KERSHAW-EDGEFIELD-SALUDA-LEXINGTON- RICHLAND-LEE-AIKEN-SUMTER-BARNWELL-ORANGEBURG-CALHOUN-CLARENDON- BAMBERG- 333 AM EDT MON MAY 9 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR EAST CENTRAL GEORGIA AND CENTRAL SOUTH CAROLINA. .DAY ONE...TODAY AND TONIGHT. NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY. THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS TUESDAY AFTERNOON AND EVENING OVER THE ENTIRE AREA. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION MAY BE NEEDED TUESDAY AFTERNOON AND EVENING.
The Columbia radar (KCAE), 33 km away, was scanning. The volume nearest the first event began at 05:57 UTC.
22 thunderstorm wind, 5 hail. Local standard time, as filed.
Public reported trees and powerlines down at Chapin Elementary School.
Public reported trees down in Whitmire.
Sheriff dispatch reported trees down in the Van Wyck community.
EM reported numerous tress and powerlines down in Lancaster. Newspaper reported 4600 people were without power throughout the county.
County EM reported trees and powerlines down in Heath Springs.
County EM reported dime to nickel size hail.
County EM reported trees down in Northern Fairfield County from White Oak to Mitford.
County EM reported trees down across Northern Fairfield County from White Oak to Mitford.
County EM reported dime to nickel size hail.
County EM reported trees and powerlines down in Heath Springs.
Public reported trees down n Pomeria.
Sheriff dispatch reported trees down across Northern Kershaw County.
Public reported 3/4 inch hail on the northeast side of Columbia.
Public reported large branches down in northeast Columbia.
Public reported and measured half dollar size hail near the southwest corner of Ft. Jackson off Leesburg Road about 2 miles east of I-77.
NWS Employee reported large limbs and trees down near Lexington.
Sheriff dispatch reported powerlines down in Lugoff and large hail of unknown size.
Spotter reported large limbs down at the intersection of Hwy. 378 and Trotter Rd. just east of Columbia.
Sheriff dispatch reported trees and powerlines down from Elgin to Lugoff to Camden and then to Bethune.
Sheriff dispatch reported trees down from Blythewood to Dentsville.
Shaw meteorologist reported 1 inch hail near Highway 378 just east of Columbia.
Sheriff dispatch reported trees down in Southeast Richland County in the Eastover area.
Spotter reported large limbs down at Patriot Pkwy and Highway 441.
Spotter reported large limbs down at Hwy. 441 and Hwy. 378 and also 1 to 2 miles south of the same intersection.
Sheriff dispatch reported trees down at Highway 378 and Highway 261 and also along Highway 261 to Wedgefield. The Sumter Newspaper also reported around 80 trees snapped off on San Souci Farms near Statesburg.
Highway patrol reported trees down near the intersection of Highway 301 and Highway 47 near Elloree.
Sheriff dispatch reported trees down between Summerton and Manning on Alex Harvin Road and also on Highway 261 west of Manning.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in South Carolina in 2011Every state in 2011This day in weather historyWarnings in South Carolina, May 2011
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: 290282, 290176, 290184, 290183, 290185, 290186, 290174, 290175, 290181, 290182, 290165, 290171, 290177, 290179, 290187, 290192, 290180, 290197, 290172, 290169, 290170, 290173, 290194, 290196, 290188, 290166, 290167.