EF0 tornado, Blaine to Darien, Illinois, May 7, 2024

1. EF065 to 85 mphthis tornado

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

2. EF186 to 110 mph

   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

EF0

Date

May 7, 2024

Touchdown

2:05 PM CDT (19:05 UTC)

Lifted

2:25 PM CDT (19:25 UTC)

On the ground

20 minutes

Path length

14.3 miles (23.1 km)

Path width

50 yards (46 m)

Deaths

0

Injuries

0

Property damage

$60,000

Counties

Boone, McHenry and Walworth counties

Touchdown point

42.440, -88.804

Lift-off point

42.532, -88.555

Record number

2405071305-03

20 damage points were recorded along this path by NWS LOT and NWS MKX, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF1. The highest wind the damage implies is 90 mph.

• Two sheep killed with barn collapse
• Roofing panels found lofted in adjacent field.
• Some tree branches snapped too.
• Horse stable. Roof collapse walls blown in.

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

Scattered thunderstorms moved across parts of northern Illinois during the afternoon of May 7th producing large hail, localized flooding and one tornado. Additional scattered thunderstorms developed during the evening of May 7th producing locally severe winds.

A few rounds of strong to severe thunderstorms moved along a stationary front that was draped across southern WI. Two tornadoes occurred with the second line of storms in the early afternoon. One of those tornadoes tracked across the IL/WI border and hit a couple barns before it ended south of Geneva Lake. Both the second and third rounds of storms produced large hail and damaging downburst winds. Mostly tree damage occurred with the downburst winds. A couple reports of flooding on the Milwaukee interstate system was also received.

A weak tornado touched down just west of Beaverton Road, about halfway between Hunter Road and Blaine Road. The tornado moved northeast producing sporadic tree damage in Boone County and crossed into McHenry County just north of Engelhardt Road.

A tornado that touched down in Boone County crossed into McHenry County just north of Perkins Road. The tornado produced scattered tree damage along its path. A barn collaspsed along Weidner Road. Several sheep were inside the barn when the tornado struck and two of the sheep were killed. It is at this location where the tornado was likely at peak intensity with estimated wind speeds of 85 mph. The tornado continued moving northeast and crossed into Walworth County in southern Wisconsin west of Lilja Road where a silo and barn were damaged.

Tornado originated in northern Illinois and came across the border into Walworth county before ending south of Geneva Lake. Damage occurred to a couple of farm outbuildings.

Brief tornado went through mainly rural lands, but did hit a horse barn where farmers were actively feeding their horses. No injuries occurred, but a door blew in and nearly hit one of the farm workers.

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 tornado watch, issued at 18:28 UTC and running to 20:00 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 Marginal Risk, with a 0.02 chance of a tornado within 25 miles. The outlook in force was issued at 16:36 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.

The Milwaukee radar (KMKX), 55 km away, was scanning. The volume nearest the touchdown began at 19:07 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 2024 tornado in IllinoisEvery tornado in Illinois since 1950Warnings in force in Illinois nowThe forecast where you are

52 more were confirmed in the United States that day.

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.

NOAA Storm Prediction Center tornado database, 1950-2025, the official record kept by NOAA's Storm Prediction Center.