Tornadoes · United States · Illinois · 2024

EF1 tornado, Vernon, Illinois, April 7, 2024

This EF1 tornado ran 1.3 miles across Marion County on April 7, 2024, touching down at 5:21 PM CDT and reaching 25 yards wide. It killed nobody, and did $30,000 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.

  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.

The record

Rating
EF1
Date
April 7, 2024
Touchdown
5:21 PM CDT (22:21 UTC)
Lifted
5:23 PM CDT (22:23 UTC)
On the ground
2 minutes
Path length
1.3 miles (2.0 km)
Path width
25 yards (23 m)
Deaths
0
Injuries
0
Property damage
$30,000
County
Marion County
Touchdown point
38.812, -89.137
Lift-off point
38.822, -89.116
Record number
2404071621-01

The damage survey

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

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 the afternoon of April 7th, convection fired along a cold front stretching along the Mississippi River. There was an isolated threat of severe weather through the evening hours. Portions of Clinton and Marion counties were impacted by this, seeing isolated large hail, damaging winds, and an EF-1 tornado.

Around 5:21 pm, a brief tornado touched down just southeast of the intersection of North 600th Street and Davis Road, where it destroyed a farm outbuilding, lofting debris into surrounding trees and powerlines. The tornado continued to the northeast causing minor damage to the roof of a small farm shed on Flat Creek Drive before lifting and dissipating. The tornado was rated EF-1 with a maximum estimated wind speed of 90 mph. The path length was 1.26 miles with a maximum path width of 25 yards. No deaths or injuries were reported.

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

The warnings

4 minutes of warning. NWS LSX issued a tornado warning for this county at 22:17 UTC, 4 minutes before the tornado touched down, in force until 23:00 UTC.

Issued (UTC)ExpiredProductOffice
22:17 UTC23:00 UTCTornado WarningLSX
22:20 UTC23:15 UTCSevere Thunderstorm WarningLSX
22:33 UTC23:15 UTCSevere Thunderstorm WarningLSX
23:00 UTC23:15 UTCSevere Thunderstorm WarningLSX
23:15 UTC00:00 UTCSevere Thunderstorm WarningLSX
01:34 UTC04:17 UTCFlood AdvisoryLSX

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 Marginal Risk, with a 0.02 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

10.4 hours before the tornado, 155 km from the path. April 7, 2024.

Skew-T log-pSkew-T log-p diagram, Lincoln, IL at 12:00Z on 2024-04-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 0 joules per kilogram, CIN -100554, lifted condensation level 1605 meters above ground. Wind barbs in knots down the right edge.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed. The warm shading is its CAPE, the cool shading the inhibition it has to break through.
HodographHodograph, Lincoln, IL at 12:00Z on 2024-04-07The wind through the lowest 10 kilometers as a curve, rings every 10 meters per second labeled in knots. Zero to 1 km storm-relative helicity 432 square meters per square second, 0 to 6 km bulk shear 45 knots.19395878Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km. RM and LM are the right and left moving storms Bunkers' method gives; the shaded area is the 0 to 1 km storm-relative helicity.
Mixed-layer CAPE
0 J/kg
Mixed-layer CIN
-100554 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
1605 m above ground
0-6 km bulk shear
45 kt
0-1 km bulk shear
36 kt
0-1 km storm-relative helicity
432 m²/s²
0-3 km storm-relative helicity
610 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
2.3 K/km

Open this sounding in Storm Lab

Lincoln, IL (KILX), 00:00Z

1.6 hours after it, 155 km from the path. April 8, 2024.

Skew-T log-pSkew-T log-p diagram, Lincoln, IL at 00:00Z on 2024-04-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 5 joules per kilogram, CIN -91, lifted condensation level 1133 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed. The warm shading is its CAPE, the cool shading the inhibition it has to break through.
HodographHodograph, Lincoln, IL at 00:00Z on 2024-04-08The wind through the lowest 10 kilometers as a curve, rings every 10 meters per second labeled in knots. Zero to 1 km storm-relative helicity 56 square meters per square second, 0 to 6 km bulk shear 70 knots.1939587897117Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km. RM and LM are the right and left moving storms Bunkers' method gives; the shaded area is the 0 to 1 km storm-relative helicity.
Mixed-layer CAPE
5 J/kg
Mixed-layer CIN
-91 J/kg
Surface CAPE
16 J/kg
Mixed-layer LCL
1133 m above ground
0-6 km bulk shear
70 kt
0-1 km bulk shear
19 kt
0-1 km storm-relative helicity
56 m²/s²
0-3 km storm-relative helicity
136 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
6.2 K/km

Open this sounding in Storm Lab

The radar

The St Louis radar (KLSX), 136 km away, was scanning. The volume nearest the touchdown began at 22:22 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)ReportWhereCountyRemark
21:49 UTCHAIL 1AvistonClinton, IL
22:08 UTCTSTM WND DMG3 Nne CarlyleClinton, IL3-4 inch tree branches down and food trailer flipped over. Time is radar estimate.
22:08 UTCTSTM WND DMG4 Nne CarlyleClinton, ILCorrects previous tstm wnd dmg report from 4 NNE Carlyle. Trees down on Hazlet Park Road. Time corrected and time is radar estimate.
22:08 UTCHAIL 13 Nne CarlyleClinton, ILWide spread damage to siding and a window is broke. Time estimate from radar.
22:21 UTCTORNADO3 Wnw VernonMarion, ILMajor loss of roof panels to a well built farm building.
22:23 UTCHAIL 1.51 Ne FerrinClinton, ILPictures provided via social media.
22:39 UTCTSTM WND DMG4 Nne CarlyleClinton, ILTrees down on Hazlet Park Road.
22:53 UTCHAIL 12 Wsw AlmaMarion, ILEstimated half inch up to one inch hail. Time estimated from radar.
23:04 UTCHAIL 11 E FarinaFayette, ILReport from mPING: Quarter (1.00 in.).
23:14 UTCTSTM WND DMGSalemMarion, ILLarge tree uprooted and fell on to a mobile home.
23:17 UTCHAIL 1SalemMarion, ILSocial media report. Time estimated on radar.
23:23 UTCHAIL 12 Ene CentraliaMarion, ILtime estimate from radar.
00:51 UTCHAIL 0.751 Ne SelmavilleMarion, ILReport from mPING: Dime (0.75 in.).

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 7, 2024

1 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
April 73:50 PM CDTEF1Hamilton, IA0.770$20,000

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.