EF1 tornado, Henry to Magnolia, Illinois, February 8, 2024

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

EF1

Date

February 8, 2024

Touchdown

4:40 PM CST (22:40 UTC)

Lifted

4:52 PM CST (22:52 UTC)

On the ground

12 minutes

Path length

10.0 miles (16.1 km)

Path width

100 yards (91 m)

Deaths

0

Injuries

0

Counties

Marshall and Putnam counties

Touchdown point

41.070, -89.360

Lift-off point

41.150, -89.200

Record number

2402081640-01

13 damage points were recorded along this path by NWS DVN and NWS ILX, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF1. The highest wind the damage implies is 110 mph.

• Preliminary damage estimate.
• Semi flipped over and damage to metal garage building.
• NWS storm survey determined straight line winds produced damage to several power poles along N 14th Rd.
• Report of a semi blown over on I-39 near Mile Marker 43

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

As a deep area of low pressure tracked slowly northeastward across the Upper Midwest, a warm front surged northward through central Illinois on February 8th. Thanks to strong southerly flow in the wake of the front, near record high temperatures in the lower to middle 60s were observed. With modest instability in place and increasing deep-layer wind shear ahead of an approaching upper wave, scattered supercell thunderstorms developed across the Illinois River Valley during the late afternoon and evening. One of the cells produced an EF-1 tornado in northern Marshall County near Henry that tracked northeastward into Putnam County. Other storms dropped hail as large as quarters.

Several thunderstorms developed across much of eastern Iowa and northwest Illinois on the afternoon and early evening of February 8, 2024. Many of these storms had pea to dime size hail. The strongest storms occurred in Jackson County, IA and Jo Daviess, Stephenson, and Putnam counties in IL. Quarter to ping pong ball size fell with the storms in Jackson, Jo Daviess, and Stephenson counties, with the larger hailstones reported near Freeport, IL. A brief tornado developed just south of the Quad Cities County Warning Area in Marshall county and moved into Putnam county. A stronger tornado developed in Wisconsin.

A tornado touched down in a field about 3 miles south of Henry at 4:40 PM CST. The tornado tracked northeastward through rural northern Marshall County, damaging numerous trees and a few farm outbuildings before crossing into southern Putnam County between County Road 1220 North and Illinois Highway 18 at 4:44 PM CST.

A tornado touched down just east of Hwy 26 south of Henry, in northern Marshall County, at 440 pm CST. It crossed into Putnam county about 300 yards southeast of IL Highway 18, around 4:44 pm CST, and later overturned a semi on Hwy 18. Several large trees were uprooted or snapped along the path. In addition, some damage to a few outbuildings was observed. The tornado then dissipated in an open field that was seen by a chaser. Estimated peak winds reached 110 mph.

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.

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 19:54 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 Lincoln radar (KILX), 107 km away, was scanning. The volume nearest the touchdown began at 22:40 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

2 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.