Tornadoes · United States · Ohio · 1973
F3 tornado, Seneca and Huron counties, Ohio, May 10, 1973
This F3 tornado ran 50.1 miles across Seneca and Huron counties on May 10, 1973, touching down at 5:40 PM EDT and reaching 27 yards wide. It killed 6 people and injured 100, and did $500,000 to $5 million of property damage.
The rating scale
Tracks are drawn in the color of the rating. The Fujita scale rates the damage rather than measuring the wind: the speeds are what that damage is taken to imply.
F040 to 72 mph
Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.
F173 to 112 mph
Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.
F2113 to 157 mph
Considerable damage. Roofs torn off well-built houses, frame homes shifted on their foundations, mobile homes destroyed, large trees snapped or uprooted, cars lifted off the ground.
F3158 to 206 mphthis tornado
Severe damage. Whole stories of well-built houses destroyed, large buildings badly damaged, trains overturned, trees debarked, heavy cars lifted and thrown.
F4207 to 260 mph
Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.
F5261 to 318 mph
Incredible damage. Strong frame houses swept off their foundations, car-sized missiles thrown more than 100 meters, steel-reinforced concrete badly damaged, high-rise buildings deformed.
Unrated
The survey recorded a tornado but could not put a number on it, most often because it crossed open country and damaged nothing a rating can be read from.
The record
- Rating
- F3
- Date
- May 10, 1973
- Touchdown
- 5:40 PM EDT (21:40 UTC)
- Path length
- 50.1 miles (80.6 km)
- Path width
- 27 yards (25 m)
- Deaths
- 6
- Injuries
- 100
- Property damage
- $500,000 to $5 million
- Counties
- Seneca and Huron counties
- Touchdown point
- 41.230, -83.430
- Lift-off point
- 41.030, -82.500
- Record number
- 344
What the Weather Service recorded
The deaths
6 direct deaths are recorded for this tornado, each with what Storm Data knows of it.
| Age | Sex | Where | Kind |
|---|---|---|---|
| Direct |
From NOAA NCEI's Storm Events Database, the narrative the local forecast office wrote for Storm Data.
The air that afternoon
The radiosonde launches on either side of the tornado, from the nearest station that was launching then, drawn and analyzed the way Storm Lab does: the same diagram, the same parcel and shear definitions SPC's mesoanalysis uses.
Dayton/James M C, OH (KDAY), 12:00Z
9.7 hours before the tornado, 172 km from the path. May 10, 1973.
- Mixed-layer CAPE
- 107 J/kg
- Mixed-layer CIN
- -132 J/kg
- Surface CAPE
- 0 J/kg
- Mixed-layer LCL
- 1181 m above ground
- 0-6 km bulk shear
- 36 kt
- 0-1 km bulk shear
- 13 kt
- 0-1 km storm-relative helicity
- 54 m²/s²
- 0-3 km storm-relative helicity
- 89 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
- 0-3 km lapse rate
- 5.5 K/km
Dayton/James M C, OH (KDAY), 00:00Z
2.3 hours after it, 172 km from the path. May 11, 1973.
- Mixed-layer CAPE
- 854 J/kg
- Mixed-layer CIN
- -9 J/kg
- Surface CAPE
- 1003 J/kg
- Mixed-layer LCL
- 1013 m above ground
- 0-6 km bulk shear
- 63 kt
- 0-1 km bulk shear
- 17 kt
- 0-1 km storm-relative helicity
- 141 m²/s²
- 0-3 km storm-relative helicity
- 210 m²/s²
- Significant tornado parameter
- 0.8
- Supercell composite
- 3.1
- 0-3 km lapse rate
- 7.5 K/km
This ground now
The live radar over the trackEvery 1973 tornado in OhioEvery tornado in Ohio since 1950Warnings in force in Ohio nowThe forecast where you are
The other tornadoes of May 10, 1973
14 more were confirmed in the United States that day.
| Date | Time | Rating | Where | Path (mi) | Width (yd) | Deaths | Injuries | Damage |
|---|---|---|---|---|---|---|---|---|
| May 10 | 11:45 AM CDT | F1 | Warren, KY | 0.1 | 10 | $500 to $5,000 | ||
| May 10 | 2:00 PM EDT | F2 | McCreary, KY | 2.7 | 10 | 5 | $5,000 to $50,000 | |
| May 10 | 1:45 PM CDT | F1 | Davidson, TN | 0.1 | 10 | $500 to $5,000 | ||
| May 10 | 2:00 PM EST | F1 | Allen, IN | 1.0 | 30 | $5,000 to $50,000 | ||
| May 10 | 2:05 PM EST | F1 | Allen, IN | 0.1 | 20 | $5,000 to $50,000 | ||
| May 10 | 2:10 PM EST | F1 | Allen, IN | 1.0 | 80 | $50,000 to $500,000 | ||
| May 10 | 2:15 PM CDT | F1 | Putnam, TN | 0.1 | 10 | $5,000 to $50,000 | ||
| May 10 | 3:30 PM EDT | F1 | Lycoming, PA | 1.6 | 67 | $50,000 to $500,000 | ||
| May 10 | 5:41 PM EDT | F2 | Wyandot, OH | 58.2 | 267 | 14 | $5,000 to $50,000 | |
| May 10 | 6:15 PM EDT | F2 | Ashland, OH | 40.4 | 667 | 8 | $50,000 to $500,000 | |
| May 10 | 6:49 PM EDT | F3 | Champaign, OH | 89.6 | 300 | 8 | $500 to $5,000 | |
| May 10 | 8:25 PM EDT | F2 | Holmes, OH | 6.2 | 17 | 1 | $50,000 to $500,000 | |
| May 10 | 10:30 PM EDT | F1 | Washington, PA | 2.0 | 10 | 3 | $5,000 to $50,000 | |
| May 10 | 11:30 PM EDT | F1 | Grainger, TN | 0.1 | 10 | $500 to $5,000 |
What this means
Ratings are the survey's, read off the damage rather than measured; the rating scale is above. Tornado counts rise through the record as reporting improved, so a year in the 1950s is not comparable with one today except for the strongest tornadoes, which were always noticed.
Sources
NOAA Storm Prediction Center tornado database, 1950-2025, the official record kept by NOAA's Storm Prediction Center.