Tornadoes · United States · Minnesota · 1985
F3 tornado, Pipestone and Murray counties, Minnesota, April 20, 1985
This F3 tornado ran 8.0 miles across Pipestone and Murray counties on April 20, 1985, touching down at 8:19 PM CST and reaching 250 yards wide. It killed nobody and injured 2, 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
- April 20, 1985
- Touchdown
- 8:19 PM CST (02:19 UTC)
- Path length
- 8.0 miles (12.9 km)
- Path width
- 250 yards (229 m)
- Deaths
- 0
- Injuries
- 2
- Property damage
- $500,000 to $5 million
- Counties
- Pipestone and Murray counties
- Touchdown point
- 43.900, -96.100
- Lift-off point
- 44.020, -96.000
- Record number
- 97
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.
Aberdeen, SD (KHON), 00:00Z
2.3 hours before the tornado, 214 km from the path. April 21, 1985.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- -10546 J/kg
- Surface CAPE
- 5 J/kg
- Mixed-layer LCL
- 1649 m above ground
- 0-6 km bulk shear
- 51 kt
- 0-1 km bulk shear
- 9 kt
- 0-1 km storm-relative helicity
- 63 m²/s²
- 0-3 km storm-relative helicity
- 292 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
- 0-3 km lapse rate
- 7.6 K/km
Aberdeen, SD (KHON), 12:00Z
9.7 hours after it, 214 km from the path. April 21, 1985.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- -9548 J/kg
- Surface CAPE
- 0 J/kg
- Mixed-layer LCL
- 1017 m above ground
- 0-6 km bulk shear
- 64 kt
- 0-1 km bulk shear
- 21 kt
- 0-1 km storm-relative helicity
- 177 m²/s²
- 0-3 km storm-relative helicity
- 346 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
- 0-3 km lapse rate
- 2.4 K/km
This ground now
The live radar over the trackEvery 1985 tornado in MinnesotaEvery tornado in Minnesota since 1950Warnings in force in Minnesota nowThe forecast where you are
The other tornadoes of April 20, 1985
13 more were confirmed in the United States that day.
| Date | Time | Rating | Where | Path (mi) | Width (yd) | Deaths | Injuries | Damage |
|---|---|---|---|---|---|---|---|---|
| April 20 | 4:36 PM CST | F1 | Holt, NE | 0.5 | 20 | |||
| April 20 | 5:05 PM CST | F1 | Knox, NE | 1.0 | 100 | $5,000 to $50,000 | ||
| April 20 | 5:10 PM CST | F2 | Knox, NE | 35.0 | 440 | $500,000 to $5 million | ||
| April 20 | 6:00 PM CST | F2 | Bon Homme, SD | 3.5 | 1,000 | $50,000 to $500,000 | ||
| April 20 | 6:01 PM CST | F1 | Bon Homme, SD | 0.1 | 10 | $5,000 to $50,000 | ||
| April 20 | 6:02 PM CST | F0 | Yankton, SD | 2.0 | 80 | |||
| April 20 | 6:06 PM CST | F0 | Yankton, SD | 0.1 | 10 | |||
| April 20 | 6:25 PM CST | F2 | Yankton, SD | 10.0 | 440 | $5,000 to $50,000 | ||
| April 20 | 6:25 PM CST | F0 | Bon Homme, SD | 0.1 | 10 | |||
| April 20 | 6:40 PM CST | F1 | Clay, SD | 0.1 | 10 | $5,000 to $50,000 | ||
| April 20 | 6:45 PM CST | F2 | Turner, SD | 12.0 | 440 | $500,000 to $5 million | ||
| April 20 | 9:42 PM CST | F1 | Woodward, OK | 3.6 | 100 | $5,000 to $50,000 | ||
| April 20 | 10:01 PM CST | F0 | Woodward, OK | 15.3 | 100 | $5,000 to $50,000 |
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.