EF1 tornado, Delavan Lake, Wisconsin, April 15, 2026

1. EF065 to 85 mph

   Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.

2. EF186 to 110 mphthis tornado

   Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.

3. 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.

4. 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.

5. EF4166 to 200 mph

   Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.

6. 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.

7. 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.

Rating, as surveyed

EF1, preliminary

Date

April 15, 2026

Touchdown

9:01 PM CDT (02:01 UTC)

Lifted

9:06 PM CDT (02:06 UTC)

On the ground

5 minutes

Path length

2.8 miles (4.5 km)

Path width

75 yards (69 m)

Deaths

0

Injuries

0

County

Walworth County

Touchdown point

42.685, -88.644

Lift-off point

42.665, -88.597

Highest wind the damage implies

100 mph

Surveyed by

NWS MKX

The office's name for it

Elkhorn

Survey last edited

April 18, 2026

Record number

None yet. SPC numbers 2026 in the spring of 2027.

Tornado began west of Quinney Rd and tracked to the southeast, hitting 4 barns as it tracked across farmland west of Elkhorn.

Written by NWS MKX in the NWS Damage Assessment Toolkit. A survey is revised as better evidence arrives.

19 damage points were recorded along this path by NWS MKX, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF1. The highest wind the damage implies is 100 mph.

• Beam from shed across the drive impaled in roof of barn, some damage to siding.
• Debris dented top of cylinder.
• Two snapped pines facing east.
• Small shed mangled, shingles from roof of house and garage lost, fascia on east side of garage missing.

Survey points are preliminary and are the raw material the published rating was built from. Source: NWS Damage Assessment Toolkit.

An organized area of low pressure tracked along a stationary over the region and brought lines and clusters of strong thunderstorms and heavy rainfall to southern WI. Flash flooding occurred in spots from Rock County to the Milwaukee area. One storm produced a tornado in Walworth county with a brief path.

The tornado began west of Quinney Road and tracked to the southeast, hitting 4 barns as it tracked across farmland west of Elkhorn.

From NOAA NCEI's Storm Events Database, the narrative the local forecast office wrote for Storm Data.

No tornado warning for this county appears in the archive as in force at the moment the tornado touched down. One was issued for the county at another hour that day.

The county was under a severe thunderstorm watch, issued at 00:57 UTC and running to 04:43 UTC.

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 Storm Prediction Center had this point in a Slight Risk, with a 0.02 chance of a tornado within 25 miles. The outlook in force was issued at 00:57 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 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.

East Troy (57C), 24 km from the path, in the two hours either side.

From the Iowa Environmental Mesonet's archive of airport observations.

The Milwaukee radar (KMKX), 33 km away, was scanning. The volume nearest the touchdown began at 02:02 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.

Local storm reports within 60 km of the path, in the three hours either side.

From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.

The live radar over the trackEvery 2026 tornado in WisconsinEvery tornado in Wisconsin since 1950Warnings in force in Wisconsin nowThe forecast where you are

6 more have been surveyed in the United States that day, so far.

Ratings are the survey's, read off the damage rather than measured; the rating scale is above. A survey can be revised, so the rating, the path and the casualties can all still change.

NWS Damage Assessment Toolkit, the record the survey teams file from the damage, and NOAA Storm Prediction Center storm reports. Neither is the official database for 2026, which SPC publishes in the spring of 2027.