Tornadoes · United States · Wisconsin · 2024
EF1 tornado, Christie to Unity, Wisconsin, May 21, 2024
From Christie to Unity, this EF1 tornado ran 4.0 miles across Clark County on May 21, 2024, touching down at 7:27 PM CDT and reaching 150 yards wide. It killed nobody, and did $270,000 of property damage.
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 mph
Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.
EF186 to 110 mphthis tornado
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
- EF1
- Date
- May 21, 2024
- Touchdown
- 7:27 PM CDT (00:27 UTC)
- Lifted
- 7:31 PM CDT (00:31 UTC)
- On the ground
- 4 minutes
- Path length
- 4.0 miles (6.5 km)
- Path width
- 150 yards (137 m)
- Deaths
- 0
- Injuries
- 0
- Property damage
- $270,000
- Crop damage
- $18,000
- County
- Clark County
- Touchdown point
- 44.846, -90.542
- Lift-off point
- 44.884, -90.479
- Record number
- 2405211827-01
The damage survey
75 damage points were recorded along this path by NWS ARX and NWS GRB, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF1. The highest wind the damage implies is 107 mph.
- Narrow but strong damage swath in satellite data.
- Harvester silo fell on barn. No signs of metal distress on the bottom of the silo, calling into question how well it was anchored.
- Loss of siding on side of church.
- Report from EM. Damage cleaned up prior to survey.
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
On May 21st, a line of severe storms moved through the region during the late afternoon and evening hours bringing widespread wind damage and several tornadoes across western Wisconsin. Additionally, a few storms produced large hail across portions of southwestern Wisconsin.
This tornado damaged several farmsteads, powerlines, and trees. It was strongest to the west of Loyal, with the path becoming weaker and less defined to the north of town.
This tornado occurred on the left flank of a broad area of downburst wind damage with the tornado path intermittent in nature as the downburst mixed in at times. Multiple farmsteads were hit with damage mainly to trees and outbuildings.
This was a brief tornado that damaged a farmstead and trees.
This was a weak and brief tornado that damaged a farmstead and a grove of trees.
A tornado touched down southwest of Unity, moved through the village, and ended northeast of town in Marathon County (NWS Green Bay's warning area). Besides damage to trees and power lines, several homes and garages had extensive damage, especially to roofs.
From NOAA NCEI's Storm Events Database, the narrative the local forecast office wrote for Storm Data.
The warnings
20 minutes of warning. NWS ARX issued a tornado warning for this county at 00:07 UTC, 20 minutes before the tornado touched down, in force until 00:45 UTC.
The county was under a tornado watch, issued at 23:43 UTC and running to 02:07 UTC.
| Issued (UTC) | Expired | Product | Office |
|---|---|---|---|
| 23:43 UTC | 02:07 UTC | Tornado Watch | ARX |
| 23:55 UTC | 01:00 UTC | Severe Thunderstorm Warning | ARX |
| 00:07 UTC | 00:45 UTC | Tornado Warning | ARX |
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 Enhanced Risk, with a 0.10 chance of a tornado within 25 miles, in the hatched area where significant tornadoes were expected. The outlook in force was issued at 19:57 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.
Green Bay/Straub, WI (KGRB), 00:00Z
0.5 hours before the tornado, 195 km from the path. May 22, 2024.
- Mixed-layer CAPE
- 442 J/kg
- Mixed-layer CIN
- -98 J/kg
- Surface CAPE
- 232 J/kg
- Mixed-layer LCL
- 1016 m above ground
- 0-6 km bulk shear
- 57 kt
- 0-1 km bulk shear
- 11 kt
- 0-1 km storm-relative helicity
- 49 m²/s²
- 0-3 km storm-relative helicity
- 149 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.1
- 0-3 km lapse rate
- 5.5 K/km
Green Bay/Straub, WI (KGRB), 12:00Z
11.5 hours after it, 195 km from the path. May 22, 2024.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- -98567 J/kg
- Surface CAPE
- 404 J/kg
- Mixed-layer LCL
- 616 m above ground
- 0-6 km bulk shear
- 34 kt
- 0-1 km bulk shear
- 18 kt
- 0-1 km storm-relative helicity
- 106 m²/s²
- 0-3 km storm-relative helicity
- 86 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
- 0-3 km lapse rate
- 3.6 K/km
The surface observations
Medford (MDZ), 31 km from the path, in the two hours either side.
| Time (UTC) | Temp (°F) | Dew point (°F) | Wind | Gust (kt) | Pressure (mb) | Weather |
|---|---|---|---|---|---|---|
| 22:35 UTC | 65 | 61.7 | 120° 9 kt | 15 | 998.6 | |
| 22:55 UTC | 65.3 | 62 | 110° 9 kt | 17 | 997.6 | |
| 23:15 UTC | 64.4 | 61 | 120° 14 kt | 20 | 997 | |
| 23:35 UTC | 63.5 | 60.3 | 120° 12 kt | 18 | 996.3 | VCTS |
| 23:55 UTC | 63 | 60 | 120° 12 kt | 20 | 995.3 | |
| 00:15 UTC | 63 | 60 | 130° 9 kt | 18 | 994.6 | VCTS |
| 00:35 UTC | 63 | 60 | 130° 8 kt | 18 | 994.2 | VCTS |
| 00:55 UTC | 61 | 57.7 | 230° 12 kt | 998 | TS | |
| 01:15 UTC | 58.6 | 55.4 | 220° 12 kt | 998 | ||
| 01:35 UTC | 58.5 | 55.2 | 200° 8 kt | 16 | 997.6 | |
| 01:55 UTC | 58.6 | 55.4 | 200° 5 kt | 996.3 | ||
| 02:20 UTC | 58 | 55 | 140° 5 kt | 995.3 |
From the Iowa Environmental Mesonet's archive of airport observations.
The radar
The La Crosse radar (KARX), 128 km away, was scanning. The volume nearest the touchdown began at 00:27 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 |
|---|---|---|---|---|
| 23:42 UTC | TSTM WND DMG | 2 W Alma Center | Jackson, WI | Barn destroyed. |
| 23:54 UTC | TORNADO | 4 E Northfield | Jackson, WI | EF1 tornado in rural northwest Jackson County that produced intermittent tree damage along its path. Estimated peak winds of 90 mph. |
| 23:56 UTC | TSTM WND DMG | 4 S Alma Center | Jackson, WI | Branches and tree damage. Time estimated. |
| 23:56 UTC | TSTM WND DMG | Augusta | Eau Claire, WI | Emergency Management reported powerlines and trees down in Augusta. Time estimated via radar. |
| 23:56 UTC | TSTM WND DMG | Augusta | Eau Claire, WI | Emergency Management reported powerlines and trees down in Augusta. Time estimated via radar. |
| 23:56 UTC | TORNADO | Augusta | Eau Claire, WI | PRELIMINARY INFORMATION: Storm survey results identified an EF1 tornado that touched down near Augusta, and moved north. The path length was about 10 miles, maximum width about 1/4 mile, and peak speeds near 90 mph. Time |
| 23:56 UTC | TORNADO | Augusta | Eau Claire, WI | PRELIMINARY INFORMATION: Storm survey results identified an EF1 tornado that touched down near Augusta, and moved north. The path length was about 10 miles, maximum width about 1/4 mile, and peak speeds near 90 mph. Time |
| 00:07 UTC | TORNADO | 4 Ene Humbird | Clark, WI | EF1 tornado that leveled trees and powerlines along a 16 mile path through Clark County, with more intermittent damage along its last 6 miles. Estimated peak winds of 105 mph. |
| 00:08 UTC | TSTM WND DMG | 6 Sse Cornell | Chippewa, WI | Branches and trees down 6 miles SSE of Cornell. Time estimated via radar. |
| 00:08 UTC | TSTM WND DMG | 6 Sse Cornell | Chippewa, WI | Branches and trees down 6 miles SSE of Cornell. Time estimated via radar. |
| 00:08 UTC | TSTM WND DMG | 9 S Boyd | Eau Claire, WI | EM reported that in the Town of Wilson there are multiple trees down in laying various directions. Time estimated by radar. |
| 00:08 UTC | TSTM WND DMG | 9 S Boyd | Eau Claire, WI | EM reported that in the Town of Wilson there are multiple trees down in laying various directions. Time estimated by radar. |
| 00:10 UTC | TSTM WND DMG | 5 Wnw Sidney | Clark, WI | Power poles and lines down along Highway 10. |
| 00:10 UTC | TSTM WND DMG | 4 Se Boyd | Chippewa, WI | 15-20 inch tree down, several 3-4 inch branches down. Time estimated via radar. |
| 00:10 UTC | TSTM WND DMG | 4 Se Boyd | Chippewa, WI | 15-20 inch tree down, several 3-4 inch branches down. Time estimated via radar. |
| 00:16 UTC | TSTM WND DMG | 4 Sse Stanley | Chippewa, WI | Multiple trees uprooted & large limbs snapped. Time estimated from radar. |
| 00:16 UTC | TSTM WND DMG | 4 Sse Stanley | Chippewa, WI | Multiple trees uprooted & large limbs snapped. Time estimated from radar. |
| 00:25 UTC | TSTM WND GST 56 | Greenwood | Clark, WI | Wisconet reading at 3 meter height. |
| 00:25 UTC | TORNADO | 2 Wnw Loyal | Clark, WI | EF0 tornado that damaged mainly trees along an intermittent 10 mile damage path through Clark County along with several outbuildings. Estimated peak winds of 85 mph. |
| 00:27 UTC | TORNADO | 4 Se Longwood | Clark, WI | EF1 tornado that traveled about 4 miles through northern Clark County producing intermittent damage. Multiple farmsteads were hit with damage mainly to trees and outbuildings. Estimated peak winds of 95 mph. |
| 00:29 UTC | TSTM WND DMG | Lublin | Taylor, WI | Report of barn blown down. Time estimated. |
| 00:30 UTC | TORNADO | 4 Ne Loyal | Clark, WI | Brief EF0 tornado that occurred just to the southeast of a longer-tracked tornado. Damage occurred to a farmstead, trees, and to a garage attached to a manufactured home. Estimated peak winds of 80 mph. |
| 00:32 UTC | TSTM WND GST 60 | 6 N Chili | Clark, WI | Trained spotter estimates 60 mph wind gust. |
| 00:34 UTC | TORNADO | 4 E Riplinger | Clark, WI | EF1 tornado that touched down southwest of Unity and traveled a little over 4 miles northeast into Marathon County. Besides damage to trees and power lines, several homes and garages had extensive damage, especially to r |
| 00:36 UTC | TORNADO | Unity | Marathon, WI | NWS survey team conducted damage survey on 5/22/24 and confirmed an EF1 tornado that impacted Unity, Wisconsin along the Clark and Marathon county line. Wind speeds were estimated at 105 mph. Time estimated from radar wh |
| 00:37 UTC | TSTM WND GST 70 | Marshfield Municipal Ai | Wood, WI | |
| 00:37 UTC | TSTM WND GST 70 | Marshfield Municipal Ai | Wood, WI | |
| 00:39 UTC | TSTM WND GST 53 | 4 Wsw Colby | Clark, WI | |
| 00:39 UTC | TSTM WND DMG | 3 Nnw Bakerville | Wood, WI | Trees down in Marshfield. Wren and Robin roads partially blocked. |
| 00:39 UTC | TSTM WND DMG | 3 Nnw Bakerville | Wood, WI | Trees down in Marshfield. Wren and Robin roads partially blocked. |
| 00:39 UTC | TSTM WND DMG | 4 Wnw Bakerville | Wood, WI | Marshfield area. Trees down at Eagle Road and County H. |
| 00:39 UTC | TSTM WND DMG | 4 Wnw Bakerville | Wood, WI | Marshfield area. Trees down at Eagle Road and County H. |
| 00:42 UTC | TSTM WND GST 50 | 2 N Dorchester | Taylor, WI | |
| 00:45 UTC | TSTM WND GST 58 | 2 Ssw Stratford | Marathon, WI | Measured at the Marshfield Wisconet station. |
| 00:45 UTC | TSTM WND GST 58 | 2 Ssw Stratford | Marathon, WI | Measured at the Marshfield Wisconet station. |
| 00:45 UTC | TORNADO | Unity | Marathon, WI | Law Enforcement has received a public report of a tornado on the ground near Unity, WI. |
| 00:45 UTC | TORNADO | Unity | Marathon, WI | Law Enforcement has received public tornado on the ground near Unity, WI. |
| 00:47 UTC | TSTM WND DMG | 1 Sw Thorp | Clark, WI | Report from mPING: 3-inch tree limbs broken; Power poles broken. |
| 00:47 UTC | TORNADO | 2 W Fenwood | Marathon, WI | NWS Green Bay Damage Survey, with coordination from Marathon County Emergency Management, found an EF-1 tornado that started at this location and went NE for 2.11 miles. Estimated Peak Wind was 87 mph. Delayed Report. |
| 00:51 UTC | TORNADO | 4 Wsw Poniatowski | Marathon, WI | EF-1 Tornado to the northwest of the Village of Edgar. 90 mph max wind speeds. 5/21/24 751 pm to 754 pm. Damage survey conducted by NWS on 5/22/24. Damage to farm buildings and silos. Damage to trees along the path of th |
From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.
This ground now
The live radar over the trackEvery 2024 tornado in WisconsinEvery tornado in Wisconsin since 1950Warnings in force in Wisconsin nowThe forecast where you are
The other tornadoes of May 21, 2024
42 more were confirmed in the United States that day.
| Date | Time | Rating | Where | Path (mi) | Width (yd) | Deaths | Injuries | Damage |
|---|---|---|---|---|---|---|---|---|
| May 21 | 4:54 AM CDT | EF0 | Polk, NE | 4.1 | 75 | $1.0 million | ||
| May 21 | 5:14 AM CDT | EF0 | Colfax, NE | 0.5 | 50 | |||
| May 21 | 5:23 AM CDT | EF0 | Butler, NE | 0.6 | 50 | |||
| May 21 | 5:27 AM CDT | EF0 | Butler, NE | 2.6 | 50 | |||
| May 21 | 5:45 AM CDT | EF0 | Saunders, NE | 0.4 | 50 | |||
| May 21 | 7:10 AM CDT | EF0 | Montgomery, IA | 0.7 | 40 | |||
| May 21 | 7:32 AM CDT | EF1 | Page, IA | 3.3 | 80 | |||
| May 21 | 12:52 PM CDT | EF0 | Saunders, NE | 0.2 | 50 | |||
| May 21 | 2:30 PM CDT | EF1 | Buena Vista, IA | 1.6 | 75 | |||
| May 21 | 2:35 PM CDT | EF1 | Montgomery, IA | 2.9 | 70 | |||
| May 21 | 2:43 PM CDT | EF3 | Page, IA | 33.9 | 1,300 | $1.0 million | ||
| May 21 | 2:57 PM CDT | EF1 | Page, IA | 1.7 | 85 | |||
| May 21 | 2:59 PM CDT | EF4 | Greenfield tornado, IA | 40.6 | 1,600 | 5 | 35 | $32 million |
| May 21 | 3:09 PM CDT | EF0 | Audubon, IA | 7.2 | 100 | $10,000 | ||
| May 21 | 3:18 PM CDT | EF1 | Adams, IA | 12.7 | 200 | $101,000 | ||
| May 21 | 3:39 PM CDT | EF2 | Adair, IA | 14.6 | 200 | $750,000 | ||
| May 21 | 3:48 PM CDT | EF0 | Martin, MN | 2.3 | 75 | |||
| May 21 | 3:50 PM CDT | EF0 | Union, IA | 4.0 | 75 | $20,000 | ||
| May 21 | 4:25 PM CDT | EF0 | Warren, IA | 1.0 | 40 | $30,000 | ||
| May 21 | 4:28 PM CDT | EF0 | Warren, IA | 2.0 | 75 | $10,000 | ||
| May 21 | 4:30 PM CDT | EF2 | Polk, IA | 40.8 | 1,000 | 4 | $8.4 million | |
| May 21 | 5:25 PM CDT | EF0 | Henry, MO | 0.3 | 50 | |||
| May 21 | 5:27 PM CDT | EF1 | Rogers, OK | 5.3 | 500 | $100,000 | ||
| May 21 | 5:39 PM CDT | EF1 | Rogers, OK | 1.0 | 100 | $10,000 | ||
| May 21 | 5:41 PM CDT | EF0 | Goodhue, MN | 0.7 | 25 | |||
| May 21 | 6:01 PM CDT | EF1 | Winona, MN to WI | 19.7 | 110 | $320,000 | ||
| May 21 | 6:14 PM CDT | EF1 | Buffalo, WI | 3.9 | 100 | $80,000 | ||
| May 21 | 6:17 PM CDT | EF1 | Buffalo, WI | 2.7 | 45 | $126,000 | ||
| May 21 | 6:34 PM CDT | EF1 | Trempealeau, WI | 0.8 | 150 | $79,000 | ||
| May 21 | 6:56 PM CDT | EF1 | Eau Claire, WI | 9.5 | 440 | |||
| May 21 | 6:59 PM CDT | EF1 | Jackson, WI | 3.1 | 75 | |||
| May 21 | 7:08 PM CDT | EF1 | Clark, WI | 7.0 | 300 | $140,000 | ||
| May 21 | 7:20 PM CDT | EF1 | Clark, WI | 9.1 | 120 | $88,000 | ||
| May 21 | 7:29 PM CDT | EF1 | Clark, WI | 2.2 | 75 | $70,000 | ||
| May 21 | 7:33 PM CDT | EF0 | Clark, WI | 1.4 | 75 | $33,000 | ||
| May 21 | 7:34 PM CDT | EF1 | Clark, WI | 4.0 | 110 | $345,000 | ||
| May 21 | 7:47 PM CDT | EF1 | Marathon, WI | 2.1 | 60 | |||
| May 21 | 7:49 PM CDT | EF1 | Dane, WI | 4.6 | 75 | $1.1 million | ||
| May 21 | 7:51 PM CDT | EF1 | Marathon, WI | 2.1 | 80 | |||
| May 21 | 7:59 PM CDT | EF1 | Marquette, WI | 5.3 | 60 | $60,000 | ||
| May 21 | 8:58 PM CDT | EF1 | Outagamie, WI | 2.7 | 80 | |||
| May 21 | 10:32 PM CDT | EF1 | Door, WI | 2.3 | 50 |
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.