4 flash flood, 2 thunderstorm wind, as filed by the National Weather Service.
Every event with a place to put it; 4 filed by county or forecast zone are drawn at its center, in a lighter ring. 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 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 Wilmington, OH wrote its last area forecast discussion before the first event at Aug 11, 1:40 PM EST, 5 hours 20 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON OH 240 PM EDT SAT AUG 11 2001 SFC WAVE HAS MOVED INTO SE INDIANA LATE THIS AFTN...WITH FRONTAL BNDRY NOW APPARENTLY NORTH OF CVG. L-M 70S DWPTS WERE POOLING ALONG AND SOUTH OF THE BNDRY...LIKELY SETTING THE STAGE FOR SOME EFFICIENT RAINERS OVER FAR SOUTHERN (NORTHERN KY) PARTS OF THE FORECAST AREA. DECENT LLVL CONVERGENCE PROGGED ACRS THE ENTIRE AREA OVERNIGHT AS WAVE MOVES ACRS...AND PLAN ON CARRYING POPS ALL ZONES. WL HIT POPS HARDEST OVER THE SOUTH WHERE PCPN EFFICIENCY THE GREATEST...AND DUE TO SLOW MOVEMENT WL MENTION +RA. BASICALLY PLANNING A 20% NORTH TO 60% FAR SOUTH BREAKDOWN. FWC TEMPS HV GOTTEN A LOT BETTER...BUT STILL WL LIKELY RAISE A DEG OR SO. GUID IN PRETTY GD AGREEMENT THAT SFC WAVE/UPPER FORCING WL SHIFT EAST OF THE CWFA BY LATE AFTN SUN...FOLLOWED BY A DEEP DRYING OF THE ATMOS. WL CARRY MORNING CHC POPS SOUTHWEST...AND THRU ERLY AFTN IN THE EAST...AND ADVERTISE SOME MANNER OF CLEARING ALL ZONES. WITH FAIRLY WIDESPRD CLDS ERLY...AND CAA KICKING IN LATE...HV UNDERCUT THE FWC TEMPS A DEG OR 2. FLOW CONTS TO AMPLIFY THRU THE SHORT RANGE...WITH THE NEW GUID INDC A WEAK BNDRY WL MV ACRS THE RGN ON MONDAY. MSTR LKS SPARSE HWVR...AND DO NOT PLAN ON INTRODUCING POPS. .ILN...NONE. JOHNSTONE
The Cincinnati radar (KILN), 65 km away, was scanning. The volume nearest the first event began at 00:12 UTC.
4 flash flood, 2 thunderstorm wind. Local standard time, as filed.
Heavy rainfall caused flooded streets. Many vehicles were stranded in the high water including an ambulance that was transporting a patient to a hospital.
Several trees knocked down.
Several inches of rain in less than 1 hour caused flooded roads around Maineville. Also, cars were submerged in water and a woman was swept through a drain pipe at the Tennis Masters Series tournament in Mason. She was injured but survived.
Trees knocked down in several locations across the county.
Heavy rainfall caused flooded roads across the county. A few of the roads were washed out.
Roads were flooded in the town of Sycamore.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Ohio in 2001Every state in 2001This day in weather historyWarnings in Ohio, August 2001
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: 5257477, 5257472, 5257476, 5257473, 5257474, 5257475.