Tornadoes · United States · Wisconsin · 2020
EF0 tornado, Cadott, Wisconsin, July 21, 2020
This EF0 tornado ran 2.9 miles across Chippewa County on July 21, 2020, touching down at 8:44 PM CDT and reaching 150 yards wide. It killed nobody.
The rating scale
Tracks are drawn in the color of the rating. The Enhanced Fujita scale rates the damage rather than measuring the wind: the speeds are what that damage is taken to imply.
EF065 to 85 mphthis tornado
Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.
EF186 to 110 mph
Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.
EF2111 to 135 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.
EF3136 to 165 mph
Severe damage. Whole stories of well-built houses destroyed, large buildings badly damaged, trains overturned, trees debarked, heavy cars lifted and thrown.
EF4166 to 200 mph
Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.
EF5over 200 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
- EF0
- Date
- July 21, 2020
- Touchdown
- 8:44 PM CDT (01:44 UTC)
- Lifted
- 8:53 PM CDT (01:53 UTC)
- On the ground
- 9 minutes
- Path length
- 2.9 miles (4.7 km)
- Path width
- 150 yards (137 m)
- Deaths
- 0
- Injuries
- 0
- County
- Chippewa County
- Touchdown point
- 44.943, -91.185
- Lift-off point
- 44.951, -91.127
- Record number
- 2007211944-01
The damage survey
24 damage points were recorded along this path by NWS MPX, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF0. The highest wind the damage implies is 85 mph.
- baseball field fencing and dugout destroyed. bleachers tossed
- trees down east of here along the tracks
- Several trees down at a cemetery.
Survey points are preliminary and are the raw material the published rating was built from. Source: NWS Damage Assessment Toolkit.
What the Weather Service recorded
During the afternoon of Tuesday, July 21st, a few thunderstorms developed along a frontal boundary over east-central Minnesota. Several spotters and storm chasers were following these storms as the storms moved into Wisconsin. ||The storm that moved into Polk County had a consistent funnel cloud associated with it with a brief tornado touchdown near Clear Lake and then again near Arland. Another storm developed across northern Dunn County and produced an EF0 tornado northeast of Wheeler. More storms developed over southeast Dunn and central Chippewa Counties to produce the majority of the damage. ||The worst damage occurred in the city of Cadott where numerous trees, power lines and a few structures were damaged as it moved through the town before dissipating.||The two tornadoes in Chippewa County had an average path length of 3 to 4 miles and an average width of 75 yards.
Numerous trees were down, with some on houses and vehicles. Part of a roof was taken off a church. Other minor roof damage was noted on homes. A shed slid off its foundation.
From NOAA NCEI's Storm Events Database, the narrative the local forecast office wrote for Storm Data.
The warnings
25 minutes of warning. NWS MPX issued a tornado warning for this county at 01:19 UTC, 25 minutes before the tornado touched down, in force until 02:00 UTC.
| Issued (UTC) | Expired | Product | Office |
|---|---|---|---|
| 00:03 UTC | 00:45 UTC | Tornado Warning | MPX |
| 01:19 UTC | 02:00 UTC | Tornado Warning | MPX |
| 01:52 UTC | 02:31 UTC | Tornado Warning | MPX |
Every warning and watch covering the touchdown point that day, from the Iowa Environmental Mesonet's archive of National Weather Service products. Lead time is measured from the issue of the warning in force to the touchdown time in the database, both of which were recorded to the minute by different people.
The forecast that day
The Storm Prediction Center had this point in a Marginal Risk, with a 0.02 chance of a tornado within 25 miles. The outlook in force was issued at 00:58 UTC.
SPC's Day 1 convective outlook as it stood when the tornado began, read at the touchdown point. The same archive is on the radar archive.
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.
Minneapolis, MN (KMPX), 00:00Z
1.7 hours before the tornado, 193 km from the path. July 22, 2020.
- Mixed-layer CAPE
- 8 J/kg
- Mixed-layer CIN
- -37 J/kg
- Surface CAPE
- 674 J/kg
- Mixed-layer LCL
- 1146 m above ground
- 0-6 km bulk shear
- 43 kt
- 0-1 km bulk shear
- 7 kt
- 0-1 km storm-relative helicity
- -2 m²/s²
- 0-3 km storm-relative helicity
- 44 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.1
- 0-3 km lapse rate
- 6.9 K/km
Minneapolis, MN (KMPX), 12:00Z
10.3 hours after it, 193 km from the path. July 22, 2020.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- -96179 J/kg
- Surface CAPE
- 0 J/kg
- Mixed-layer LCL
- 996 m above ground
- 0-6 km bulk shear
- 30 kt
- 0-1 km bulk shear
- 23 kt
- 0-1 km storm-relative helicity
- -10 m²/s²
- 0-3 km storm-relative helicity
- -30 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
- 0-3 km lapse rate
- 2.7 K/km
The surface observations
Eau Claire (EAU), 27 km from the path, in the two hours either side.
| Time (UTC) | Temp (°F) | Dew point (°F) | Wind | Gust (kt) | Pressure (mb) | Weather |
|---|---|---|---|---|---|---|
| 23:15 UTC | 160° 7 kt | 1010.8 | ||||
| 23:20 UTC | 180° 5 kt | 1010.8 | ||||
| 23:25 UTC | 170° 5 kt | 1010.5 | ||||
| 23:35 UTC | 180° 9 kt | 1010.5 | ||||
| 23:40 UTC | 170° 8 kt | 1010.8 | ||||
| 23:45 UTC | 180° 5 kt | 1010.8 | ||||
| 23:50 UTC | 180° 8 kt | 1010.8 | ||||
| 23:56 UTC | 77 | 66 | 170° 6 kt | 1010.8 | ||
| 00:00 UTC | 190° 8 kt | 1010.8 | ||||
| 00:05 UTC | 180° 5 kt | 1010.8 | ||||
| 00:10 UTC | 190° 5 kt | 1010.8 | ||||
| 00:15 UTC | 170° 5 kt | 1010.5 | ||||
| 00:20 UTC | 170° 5 kt | 1010.5 | ||||
| 00:25 UTC | 160° 5 kt | 1010.5 | ||||
| 00:30 UTC | 170° 5 kt | 1010.5 | ||||
| 00:35 UTC | 170° 7 kt | 1010.5 | ||||
| 00:40 UTC | 180° 7 kt | 1010.5 | ||||
| 00:50 UTC | 180° 5 kt | 1010.2 | ||||
| 00:55 UTC | 180° 7 kt | 1010.2 | ||||
| 00:56 UTC | 75 | 67 | 180° 7 kt | 1010.2 | ||
| 01:00 UTC | 180° 5 kt | 1010.2 | ||||
| 01:05 UTC | 180° 8 kt | 1010.2 | ||||
| 01:10 UTC | 180° 5 kt | 1010.2 | ||||
| 01:15 UTC | 170° 5 kt | 1010.2 | ||||
| 01:20 UTC | 160° 5 kt | 1010.2 | ||||
| 01:25 UTC | 150° 8 kt | 1010.2 | ||||
| 01:30 UTC | 170° 10 kt | 1010.2 | ||||
| 01:35 UTC | 75 | 67 | 230° 9 kt | 1010.5 | VCTS | |
| 01:35 UTC | 230° 9 kt | 1010.5 | ||||
| 01:40 UTC | 300° 7 kt | 1010.5 | ||||
| 01:42 UTC | 74 | 67 | 300° 9 kt | 1010.5 | VCTS | |
| 01:45 UTC | 11 kt | 1010.8 | ||||
| 01:50 UTC | 330° 11 kt | 17 | 1010.8 | |||
| 01:55 UTC | 330° 10 kt | 1011.2 | ||||
| 01:56 UTC | 71 | 63 | 330° 11 kt | 30 | 1011.2 | VCTS |
| 02:00 UTC | 320° 10 kt | 1011.2 | ||||
| 02:03 UTC | 69 | 63 | 330° 10 kt | 17 | 1011.2 | VCTS -RA |
| 02:10 UTC | 350° 2 kt | 1011.2 | +RA BR | |||
| 02:14 UTC | 67 | 64 | 4 kt | 1011.5 | VCTS RA BR | |
| 02:15 UTC | 300° 5 kt | 1011.5 | RA BR | |||
| 02:17 UTC | 67 | 64 | 310° 5 kt | 1011.2 | -RA BR | |
| 02:20 UTC | 350° 4 kt | 1011.5 | -RA | |||
| 02:30 UTC | 330° 4 kt | 1011.5 | ||||
| 02:40 UTC | 320° 2 kt | 1011.9 | ||||
| 02:50 UTC | 280° 2 kt | 1011.9 | ||||
| 02:55 UTC | 0° 0 kt | 1011.9 | ||||
| 02:56 UTC | 67 | 64 | 0° 0 kt | 1011.9 | ||
| 03:00 UTC | 0° 0 kt | 1011.9 | ||||
| 03:05 UTC | 0° 0 kt | 1011.9 |
From the Iowa Environmental Mesonet's archive of airport observations.
The radar
The La Crosse radar (KARX), 125 km away, was scanning. The volume nearest the touchdown began at 01:41 UTC.
Open the radar archive at this moment, over the track
Reflectivity and velocity, decoded from the Level II archive in the browser. Volumes take a few seconds to open the first time.
What was reported nearby
Local storm reports within 60 km of the path, in the three hours either side.
| Time (UTC) | Report | Where | County | Remark |
|---|---|---|---|---|
| 23:35 UTC | FUNNEL CLOUD | 8 Wsw New Auburn | Dunn, WI | |
| 23:41 UTC | TORNADO | 6 Ne Wheeler | Dunn, WI | BRIEF TOUCHDOWN NORTHEAST OF WHEELER. |
| 01:16 UTC | TORNADO | 5 Ene Elk Mound | Chippewa, WI | STORM SPOTTERS INDICATED A TORNADO EAST OF ELK MOUND MOVING EAST. |
| 01:26 UTC | TORNADO | 5 Nnw Eau Claire | Chippewa, WI | SEVERAL TRAINED SPOTTERS CONFIRMED A TORNADO NEAR HIGHWAY 29, NORTH OF EAU CLAIRE. THERE WAS DEBRIS ASSOCIATED WITH THE FUNNEL THAT MADE CONTACT WITH THE GROUND. IT LASTED FOR 4 MINUTES BEFORE LIFTING. |
| 01:45 UTC | TORNADO | 3 S Chippewa Falls | Chippewa, WI | BRIEF TOUCHDOWN REPORTED. |
| 01:53 UTC | TORNADO | Cadott | Chippewa, WI | A TORNADO WAS CONFIRMED MOVING THROUGH THE TOWN OF CADOTT. THE SPOTTER NOTED POWER FLASHES AS IT WENT THROUGH THE TOWN. LAW ENFORCEMENT OFFICIALS ARE IN ROUTE. |
| 01:55 UTC | TORNADO | Cadott | Chippewa, WI | THE LOCAL LAW ENFORCEMENT OFFICIALS AND SPOTTERS INDICATED THAT DAMAGE OCCURRED ON THE NORTH SIDE OF THE VILLAGE OF CADOTT, MAINLY NORTH OF THE RAILROAD TRACK AND WEST OF HIGHWAY 27. THERE WAS ROOF DAMAGE TO A CHURCH AND |
| 02:32 UTC | FUNNEL CLOUD | 2 W Gilman | Taylor, WI | SPOTTED NEAR THE INTERSECTION OF EAST EDDY LN AND STATE HWY 64. |
| 02:32 UTC | FUNNEL CLOUD | 2 W Gilman | Taylor, WI | SPOTTED NEAR THE INTERSECTION OF EAST EDDY LN AND STATE HWY 64. && |
From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.
This ground now
The live radar over the trackEvery 2020 tornado in WisconsinEvery tornado in Wisconsin since 1950Warnings in force in Wisconsin nowThe forecast where you are
The other tornadoes of July 21, 2020
6 more were confirmed in the United States that day.
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.