Tornadoes · United States · Missouri · 2024
EF0 tornado, Calhoun, Missouri, May 21, 2024
This EF0 tornado ran 0.3 miles across Henry County on May 21, 2024, touching down at 5:25 PM CDT and reaching 50 yards wide. It killed nobody.
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
- May 21, 2024
- Touchdown
- 5:25 PM CDT (22:25 UTC)
- Lifted
- 5:26 PM CDT (22:26 UTC)
- On the ground
- 1 minutes
- Path length
- 0.3 miles (0.6 km)
- Path width
- 50 yards (46 m)
- Deaths
- 0
- Injuries
- 0
- County
- Henry County
- Touchdown point
- 38.465, -93.594
- Lift-off point
- 38.467, -93.588
- Record number
- 2405211625-01
The damage survey
3 damage points were recorded along this path by NWS EAX, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF0. The highest wind the damage implies is 85 mph.
- Nailed sill plate to concrete slab for back half of structure. Fire Chief next door measured 91mph on his anamometor, which was to the north and northwest of his property, about 150 yards from track. Based on construction and debris spread, hard to go EF-1 damage, believe winds were 85 mph.
- Fire Chief lost two apple tree branches on the northwest side of the EF-0 Track.
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 May 21st, strong to severe storms developed over far eastern Kansas, and moved into western Missouri. These storms produced some hail, damaging wind gusts, and one tornado in Henry County.
At 5:26 PM CDT a brief EF-0 Tornado occurred east of Calhoun, MO just north of MO Hwy OO. The tornado lifted the roof off of a metal outbuilding, tossing the metal sides and roof to the north and northwest as well as some of the lighter contents of the structure. The tornado continued to track northeast for 0.35 miles, resulting in minor tree debris.
From NOAA NCEI's Storm Events Database, the narrative the local forecast office wrote for Storm Data.
The warnings
0 minutes of warning. NWS EAX issued a tornado warning for this county at 22:25 UTC, 0 minutes before the tornado touched down, in force until 22:38 UTC.
The county was under a tornado watch, issued at 19:43 UTC and running to 23:43 UTC.
| Issued (UTC) | Expired | Product | Office |
|---|---|---|---|
| 19:43 UTC | 23:43 UTC | Tornado Watch | EAX |
| 21:39 UTC | 22:15 UTC | Severe Thunderstorm Warning | EAX |
| 22:10 UTC | 22:45 UTC | Severe Thunderstorm Warning | EAX |
| 22:25 UTC | 22:38 UTC | Tornado Warning | EAX |
| 22:42 UTC | 23:00 UTC | Severe Thunderstorm Warning | EAX |
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 19:57 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 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.
Springfield, MO (KSGF), 12:00Z
10.4 hours before the tornado, 175 km from the path. May 21, 2024.
- Mixed-layer CAPE
- 594 J/kg
- Mixed-layer CIN
- -286 J/kg
- Surface CAPE
- 166 J/kg
- Mixed-layer LCL
- 999 m above ground
- 0-6 km bulk shear
- 39 kt
- 0-1 km bulk shear
- 7 kt
- 0-1 km storm-relative helicity
- 27 m²/s²
- 0-3 km storm-relative helicity
- 82 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
- 0-3 km lapse rate
- 3.8 K/km
Springfield, MO (KSGF), 00:00Z
1.6 hours after it, 175 km from the path. May 22, 2024.
- Mixed-layer CAPE
- 1607 J/kg
- Mixed-layer CIN
- -43 J/kg
- Surface CAPE
- 2548 J/kg
- Mixed-layer LCL
- 912 m above ground
- 0-6 km bulk shear
- 57 kt
- 0-1 km bulk shear
- 34 kt
- 0-1 km storm-relative helicity
- 341 m²/s²
- 0-3 km storm-relative helicity
- 268 m²/s²
- Significant tornado parameter
- 3.4
- Supercell composite
- 16.1
- 0-3 km lapse rate
- 6.5 K/km
The radar
The Pleasant Hill radar (KEAX), 70 km away, was scanning. The volume nearest the touchdown began at 22:27 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 |
|---|---|---|---|---|
| 22:09 UTC | TSTM WND DMG | 1 Nne Clinton | Henry, MO | Trees snapped and tree limbs broken in area Gaines Drive and N 2nd St. Building post sign blown over and fence damaged by outflow winds. |
| 22:10 UTC | TSTM WND DMG | Clinton | Henry, MO | Report of large tree limbs and powerlines down. Time estimated from radar. |
| 22:17 UTC | HAIL 1 | Appleton City | St. Clair, MO | Delayed report. Hail ranged from pea to quarter size. Lasted five minutes. |
| 22:26 UTC | TSTM WND DMG | 1 Ene Calhoun | Henry, MO | Barn largely destroyed near Calhoun. |
| 22:26 UTC | TORNADO | 2 E Calhoun | Henry, MO | Corrects previous tornado report from 2 E Calhoun. NWS Damage Survey confirmed a brief EF-0 Tornado occurred east of Calhoun, MO just north of MO Hwy OO. The tornado lifted the roof off of a metal outbuilding, tossing th |
| 22:26 UTC | TORNADO | 2 E Calhoun | Henry, MO | NWS Damage Survey confirmed a brief EF-0 Tornado occurred east of Calhoun, MO just north of MO Hwy OO. The tornado lifted the roof off of a metal outbuilding, tossing the metal sides and roof to the north and northwest a |
| 22:52 UTC | TSTM WND DMG | 1 Wsw Lowry City | St. Clair, MO | Small branches down Highway D and 1st St. Dime size hail. Estimated 60 mph wind gust. |
| 23:02 UTC | TSTM WND DMG | 1 Ene Warsaw | Benton, MO | Tree down on powerline. power outage in town. |
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 MissouriEvery tornado in Missouri since 1950Warnings in force in Missouri nowThe forecast where you are
The other tornadoes of May 21, 2024
42 more were confirmed in the United States that day.
| Date | Time | Rating | Where | Path (mi) | Width (yd) | Deaths | Injuries | Damage |
|---|---|---|---|---|---|---|---|---|
| May 21 | 4:54 AM CDT | EF0 | Polk, NE | 4.1 | 75 | $1.0 million | ||
| May 21 | 5:14 AM CDT | EF0 | Colfax, NE | 0.5 | 50 | |||
| May 21 | 5:23 AM CDT | EF0 | Butler, NE | 0.6 | 50 | |||
| May 21 | 5:27 AM CDT | EF0 | Butler, NE | 2.6 | 50 | |||
| May 21 | 5:45 AM CDT | EF0 | Saunders, NE | 0.4 | 50 | |||
| May 21 | 7:10 AM CDT | EF0 | Montgomery, IA | 0.7 | 40 | |||
| May 21 | 7:32 AM CDT | EF1 | Page, IA | 3.3 | 80 | |||
| May 21 | 12:52 PM CDT | EF0 | Saunders, NE | 0.2 | 50 | |||
| May 21 | 2:30 PM CDT | EF1 | Buena Vista, IA | 1.6 | 75 | |||
| May 21 | 2:35 PM CDT | EF1 | Montgomery, IA | 2.9 | 70 | |||
| May 21 | 2:43 PM CDT | EF3 | Page, IA | 33.9 | 1,300 | $1.0 million | ||
| May 21 | 2:57 PM CDT | EF1 | Page, IA | 1.7 | 85 | |||
| May 21 | 2:59 PM CDT | EF4 | Greenfield tornado, IA | 40.6 | 1,600 | 5 | 35 | $32 million |
| May 21 | 3:09 PM CDT | EF0 | Audubon, IA | 7.2 | 100 | $10,000 | ||
| May 21 | 3:18 PM CDT | EF1 | Adams, IA | 12.7 | 200 | $101,000 | ||
| May 21 | 3:39 PM CDT | EF2 | Adair, IA | 14.6 | 200 | $750,000 | ||
| May 21 | 3:48 PM CDT | EF0 | Martin, MN | 2.3 | 75 | |||
| May 21 | 3:50 PM CDT | EF0 | Union, IA | 4.0 | 75 | $20,000 | ||
| May 21 | 4:25 PM CDT | EF0 | Warren, IA | 1.0 | 40 | $30,000 | ||
| May 21 | 4:28 PM CDT | EF0 | Warren, IA | 2.0 | 75 | $10,000 | ||
| May 21 | 4:30 PM CDT | EF2 | Polk, IA | 40.8 | 1,000 | 4 | $8.4 million | |
| May 21 | 5:27 PM CDT | EF1 | Rogers, OK | 5.3 | 500 | $100,000 | ||
| May 21 | 5:39 PM CDT | EF1 | Rogers, OK | 1.0 | 100 | $10,000 | ||
| May 21 | 5:41 PM CDT | EF0 | Goodhue, MN | 0.7 | 25 | |||
| May 21 | 6:01 PM CDT | EF1 | Winona, MN to WI | 19.7 | 110 | $320,000 | ||
| May 21 | 6:14 PM CDT | EF1 | Buffalo, WI | 3.9 | 100 | $80,000 | ||
| May 21 | 6:17 PM CDT | EF1 | Buffalo, WI | 2.7 | 45 | $126,000 | ||
| May 21 | 6:34 PM CDT | EF1 | Trempealeau, WI | 0.8 | 150 | $79,000 | ||
| May 21 | 6:56 PM CDT | EF1 | Eau Claire, WI | 9.5 | 440 | |||
| May 21 | 6:59 PM CDT | EF1 | Jackson, WI | 3.1 | 75 | |||
| May 21 | 7:08 PM CDT | EF1 | Clark, WI | 7.0 | 300 | $140,000 | ||
| May 21 | 7:20 PM CDT | EF1 | Clark, WI | 9.1 | 120 | $88,000 | ||
| May 21 | 7:27 PM CDT | EF1 | Clark, WI | 4.0 | 150 | $270,000 | ||
| May 21 | 7:29 PM CDT | EF1 | Clark, WI | 2.2 | 75 | $70,000 | ||
| May 21 | 7:33 PM CDT | EF0 | Clark, WI | 1.4 | 75 | $33,000 | ||
| May 21 | 7:34 PM CDT | EF1 | Clark, WI | 4.0 | 110 | $345,000 | ||
| May 21 | 7:47 PM CDT | EF1 | Marathon, WI | 2.1 | 60 | |||
| May 21 | 7:49 PM CDT | EF1 | Dane, WI | 4.6 | 75 | $1.1 million | ||
| May 21 | 7:51 PM CDT | EF1 | Marathon, WI | 2.1 | 80 | |||
| May 21 | 7:59 PM CDT | EF1 | Marquette, WI | 5.3 | 60 | $60,000 | ||
| May 21 | 8:58 PM CDT | EF1 | Outagamie, WI | 2.7 | 80 | |||
| May 21 | 10:32 PM CDT | EF1 | Door, WI | 2.3 | 50 |
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.