Tornadoes · United States · Illinois · 2024
EF0 tornado, Saint Clair County, Illinois, April 18, 2024
This EF0 tornado ran 1.1 miles across Saint Clair County on April 18, 2024, touching down at 5:58 PM CDT and reaching 35 yards wide. It killed nobody, and did $10,000 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 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
- April 18, 2024
- Touchdown
- 5:58 PM CDT (22:58 UTC)
- Lifted
- 5:59 PM CDT (22:59 UTC)
- On the ground
- 1 minutes
- Path length
- 1.1 miles (1.8 km)
- Path width
- 35 yards (32 m)
- Deaths
- 0
- Injuries
- 0
- Property damage
- $10,000
- County
- Saint Clair County
- Touchdown point
- 38.552, -90.177
- Lift-off point
- 38.554, -90.157
- Record number
- 2404181658-01
The damage survey
10 damage points were recorded along this path by NWS LSX, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF0. The highest wind the damage implies is 80 mph.
Survey points are preliminary and are the raw material the published rating was built from. Source: NWS Damage Assessment Toolkit.
The warnings
9 minutes of warning. NWS LSX issued a tornado warning for this county at 22:49 UTC, 9 minutes before the tornado touched down, in force until 23:30 UTC.
The county was under a severe thunderstorm watch, issued at 17:59 UTC and running to 00:56 UTC.
| Issued (UTC) | Expired | Product | Office |
|---|---|---|---|
| 17:59 UTC | 00:56 UTC | Severe Thunderstorm Watch | LSX |
| 22:25 UTC | 23:30 UTC | Severe Thunderstorm Warning | LSX |
| 22:39 UTC | 23:45 UTC | Severe Thunderstorm Warning | LSX |
| 22:49 UTC | 23:30 UTC | Tornado Warning | LSX |
| 23:10 UTC | 23:47 UTC | Tornado Warning | LSX |
| 23:13 UTC | 00:20 UTC | Severe Thunderstorm Warning | LSX |
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 0.05 chance of a tornado within 25 miles. The outlook in force was issued at 19:53 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.
Lincoln, IL (KILX), 12:00Z
11.0 hours before the tornado, 223 km from the path. April 18, 2024.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- -105739 J/kg
- Surface CAPE
- 0 J/kg
- Mixed-layer LCL
- 1827 m above ground
- 0-6 km bulk shear
- 35 kt
- 0-1 km bulk shear
- 13 kt
- 0-1 km storm-relative helicity
- 90 m²/s²
- 0-3 km storm-relative helicity
- 269 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
- 0-3 km lapse rate
- 3.0 K/km
Lincoln, IL (KILX), 00:00Z
1.0 hours after it, 223 km from the path. April 19, 2024.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- -88178 J/kg
- Surface CAPE
- 0 J/kg
- Mixed-layer LCL
- 1011 m above ground
- 0-6 km bulk shear
- 69 kt
- 0-1 km bulk shear
- 33 kt
- 0-1 km storm-relative helicity
- 468 m²/s²
- 0-3 km storm-relative helicity
- 850 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
- 0-3 km lapse rate
- 5.0 K/km
The radar
The St Louis radar (KLSX), 48 km away, was scanning. The volume nearest the touchdown began at 22:57 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 |
|---|---|---|---|---|
| 22:40 UTC | TSTM WND DMG | 1 E East Carondelet | St. Clair, IL | location approximate, time estimate from radar, multiple trees and powerlines down. |
| 22:52 UTC | TORNADO | 1 S Pontoon Beach | Madison, IL | Tree damage with winds up to 80 mph. NWS storm survey continues. |
| 22:57 UTC | TSTM WND DMG | 1 Sw Dupo | St. Clair, IL | Report from mPING: 3-inch tree limbs broken; Power poles broken. |
| 22:57 UTC | TSTM WND DMG | 2 Nw Columbia | Monroe, IL | Report from mPING: 1-inch tree limbs broken; Shingles blown off. |
| 22:58 UTC | TORNADO | 1 Se Cahokia | St. Clair, IL | The tornado touched down near the western edge of the Prairies of Cahokia Golf Course and moved east for about 1.1 miles where it lifted near the intersection of Carol Rd and Lynn St. Damage consisted of uprooted trees a |
| 23:01 UTC | TORNADO | 1 S Prairietown | Madison, IL | Corrects previous tstm wnd dmg report from 1 S Prairietown. Report from mPING: Trees uprooted or snapped; Roof blown off. NWS survey team found EF1 damage with max winds to 95 mph. |
| 23:02 UTC | TSTM WND DMG | 1 S Prairietown | Madison, IL | Report from mPING: Trees uprooted or snapped; Roof blown off. |
| 23:05 UTC | TSTM WND DMG | 1 E Troy | Madison, IL | Large tree blown over. |
| 23:06 UTC | TSTM WND DMG | Worden | Madison, IL | power poles down. |
| 23:09 UTC | TORNADO | 3 Se Kuhn | Madison, IL | Tree damage (limbs snapped) and minor roof damage (shingles off) along Lower Marine Road. NWS storm survey continues. |
| 23:14 UTC | TSTM WND DMG | Marine | Madison, IL | Corrects previous tornado report from Marine. Corrects previous tstm wnd dmg report from Marine. trees down, trees in houses, and powerlines down. |
| 23:14 UTC | TORNADO | Marine | Madison, IL | Corrects previous tstm wnd dmg report from Marine. trees down, trees in houses, and powerlines down. NWS survey team determined the damage was from a EF0 tornado. Maximum winds of 80 mph. |
| 23:15 UTC | TSTM WND DMG | 2 Ese Centreville | St. Clair, IL | Downed tree and powerlines. |
| 23:15 UTC | TSTM WND DMG | Marine | Madison, IL | trees down, trees in houses, and powerlines down. |
| 23:18 UTC | TSTM WND DMG | 1 E O'Fallon | St. Clair, IL | Report from mPING: 3-inch tree limbs broken; Power poles broken. |
| 23:19 UTC | TSTM WND DMG | 1 Nw Fairview Heights | St. Clair, IL | Report from mPING: 3-inch tree limbs broken; Power poles broken. |
| 23:55 UTC | TSTM WND DMG | 1 Ene Okawville | Washington, IL | Tree debris was found off of I-64 at the Okawville exit. Time estimated from radar. |
| 23:55 UTC | HAIL 1.25 | Okawville | Washington, IL |
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 IllinoisEvery tornado in Illinois since 1950Warnings in force in Illinois nowThe forecast where you are
The other tornadoes of April 18, 2024
13 more were confirmed in the United States that day.
| Date | Time | Rating | Where | Path (mi) | Width (yd) | Deaths | Injuries | Damage |
|---|---|---|---|---|---|---|---|---|
| April 18 | 1:30 PM PDT | EF0 | Spokane, WA | 0.0 | 5 | |||
| April 18 | 4:51 PM CDT | Unrated | Greene, IL | 4.3 | 10 | |||
| April 18 | 5:30 PM CDT | EF1 | Jefferson, MO | 7.8 | 40 | $100,000 | ||
| April 18 | 5:36 PM CDT | Unrated | Jersey, IL | 0.0 | 10 | |||
| April 18 | 5:52 PM CDT | EF0 | Madison, IL | 0.9 | 100 | |||
| April 18 | 5:52 PM CDT | EF1 | Macoupin, IL | 0.2 | 75 | $50,000 | ||
| April 18 | 5:57 PM CDT | EF1 | Madison, IL | 3.1 | 75 | $100,000 | ||
| April 18 | 6:09 PM CDT | EF0 | Madison, IL | 0.3 | 75 | $5,000 | ||
| April 18 | 6:13 PM CDT | EF0 | Madison, IL | 4.4 | 100 | $10,000 | ||
| April 18 | 7:18 PM CDT | EF1 | Logan, IL | 3.8 | 200 | 1 | ||
| April 18 | 7:23 PM CDT | EF1 | Macon, IL | 2.1 | 300 | |||
| April 18 | 7:27 PM CDT | EF1 | Macon, IL | 3.7 | 200 | |||
| April 18 | 7:37 PM CDT | EF1 | Macon, IL | 7.2 | 500 |
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.