Tornadoes · United States · Iowa · 2024

EF0 tornado, Madrid to Napier, Iowa, May 24, 2024

From Madrid to Napier, this EF0 tornado ran 10.7 miles across Boone County on May 24, 2024, touching down at 4:42 AM CDT and reaching 180 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.

  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.

The record

Rating
EF0
Date
May 24, 2024
Touchdown
4:42 AM CDT (09:42 UTC)
Lifted
4:54 AM CDT (09:54 UTC)
On the ground
12 minutes
Path length
10.7 miles (17.2 km)
Path width
180 yards (165 m)
Deaths
0
Injuries
0
Property damage
$10,000
County
Boone County
Touchdown point
41.895, -93.931
Lift-off point
41.941, -93.733
Record number
2405240342-01

What the Weather Service recorded

A strong QLCS moved across central Iowa during the early morning hours of May 24 producing widespread wind damage and five tornadoes.

This QLCS tornado started a few miles north of Woodward and moved eastward quickly. Most of the damage along the entire path was to trees although one farmstead south of Luther had damage to one of the outbuildings. The tornado lifted to the south of Napier in eastern Boone County.

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

The warnings

28 minutes of warning. NWS DMX issued a tornado warning for this county at 09:14 UTC, 28 minutes before the tornado touched down, in force until 09:45 UTC.

The county was under a severe thunderstorm watch, issued at 07:44 UTC and running to 11:07 UTC.

Issued (UTC)ExpiredProductOffice
07:44 UTC11:07 UTCSevere Thunderstorm WatchDMX
08:56 UTC09:45 UTCSevere Thunderstorm WarningDMX
09:00 UTC18:00 UTCFlood WatchDMX
09:14 UTC09:45 UTCTornado WarningDMX
09:28 UTC10:00 UTCTornado WarningDMX
09:40 UTC10:30 UTCSevere Thunderstorm WarningDMX
09:41 UTC10:15 UTCTornado WarningDMX
09:46 UTC10:07 UTCTornado WarningDMX
12:00 UTC15:01 UTCFlood WatchDMX
17:39 UTC19:03 UTCFlood WarningDMX

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 General Thunderstorms Risk. The outlook in force was issued at 05:52 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.

Omaha, NE (KOAX), 00:00Z

9.7 hours before the tornado, 221 km from the path. May 24, 2024.

Skew-T log-pSkew-T log-p diagram, Omaha, NE at 00:00Z on 2024-05-24Temperature 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 -100176, lifted condensation level 2328 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, Omaha, NE at 00:00Z on 2024-05-24The 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 61 square meters per square second, 0 to 6 km bulk shear 32 knots.193958Sfc1 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
-100176 J/kg
Surface CAPE
184 J/kg
Mixed-layer LCL
2328 m above ground
0-6 km bulk shear
32 kt
0-1 km bulk shear
11 kt
0-1 km storm-relative helicity
61 m²/s²
0-3 km storm-relative helicity
226 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
7.4 K/km

Open this sounding in Storm Lab

Omaha, NE (KOAX), 12:00Z

2.3 hours after it, 221 km from the path. May 24, 2024.

Skew-T log-pSkew-T log-p diagram, Omaha, NE at 12:00Z on 2024-05-24Temperature 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 -91020, lifted condensation level 1012 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, Omaha, NE at 12:00Z on 2024-05-24The 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 -89 square meters per square second, 0 to 6 km bulk shear 67 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
-91020 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
1012 m above ground
0-6 km bulk shear
67 kt
0-1 km bulk shear
29 kt
0-1 km storm-relative helicity
-89 m²/s²
0-3 km storm-relative helicity
-2 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3
0-3 km lapse rate
4.0 K/km

Open this sounding in Storm Lab

The radar

The Des Moines radar (KDMX), 23 km away, was scanning. The volume nearest the touchdown began at 09:42 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
08:05 UTCHAIL 0.88ElkhartPolk, IAPea to nickel sized hail in Elkhart. Delayed report.
08:20 UTCHAIL 1.254 Ssw NevadaStory, IASocial Media report between Cambridge and Nevada.
08:20 UTCHAIL 1.254 Ssw NevadaStory, IASocial Media report between Cambridge and Nevada.
08:30 UTCHAIL 1NevadaStory, IA
08:30 UTCHAIL 1NevadaStory, IA
09:32 UTCTSTM WND GST 633 Wsw PerryDallas, IAPeak wind at Perry Airport.
09:32 UTCTSTM WND GST 633 Wsw PerryDallas, IAPeak wind at Perry Airport.
09:40 UTCTSTM WND DMGBoxholmBoone, IADelayed social media picture of power poles down near Boxholm. Time estimated by radar.
09:40 UTCTSTM WND DMGBoxholmBoone, IADelayed social media picture of power poles down near Boxholm. Time estimated by radar.
09:40 UTCTSTM WND GST 652 N PattersonMadison, IAReported by Trained Spotter.
09:40 UTCTSTM WND GST 652 N PattersonMadison, IAReported by Trained Spotter.
09:47 UTCTSTM WND DMGMadridBoone, IACorrects previous tstm wnd dmg report from Madrid. Large branch and power line down in street.
09:47 UTCTSTM WND DMGMadridBoone, IACorrects previous tstm wnd dmg report from Madrid. Large branch and power line down in street.
09:47 UTCTSTM WND DMGMadridBoone, IALarge branch and power line down in street.
09:55 UTCTSTM WND DMG1 Nnw West Des MoinesPolk, IADelayed report of a tree down on a house. Time estimated from radar.
09:55 UTCTSTM WND DMGJohnstonPolk, IADelayed report. Social media picture of large tree branches down in Johnston. Time estimated by radar.
09:55 UTCTSTM WND DMGJohnstonPolk, IADelayed report. Social media picture of large tree branches down in Johnston. Time estimated by radar.
09:55 UTCTORNADO1 E JohnstonPolk, IANWS damage survey identified damage consistent with an EF0 tornado that tracked from southern into eastern portions of Johnston from 453 AM to 457 AM.
10:00 UTCTSTM WND DMG2 Sse AmesStory, IADelayed social media report of a large tree down on the south side of Ames. Time estimated by radar.
10:00 UTCTSTM WND DMG2 Sse AmesStory, IADelayed social media report of a large tree down on the south side of Ames. Time estimated by radar.
10:04 UTCTSTM WND DMG1 Sw PerryDallas, IASeveral larger trees down in Perry. 3500 without power in Perry.
10:04 UTCTSTM WND DMG1 Sw PerryDallas, IASeveral larger trees down in Perry. 3500 without power in Perry.
10:04 UTCTSTM WND GST 58JohnstonPolk, IAPersonal weather station.
10:04 UTCTSTM WND GST 58JohnstonPolk, IAPersonal weather station.
10:07 UTCTSTM WND DMG1 Se AmesStory, IALarge tree snapped on S Duff on the south edge of town. Time and location estimated with radar. Relayed with social media.
10:07 UTCTSTM WND DMG1 Se AmesStory, IALarge tree snapped on S Duff on the south edge of town. Time and location estimated with radar. Relayed with social media.
10:08 UTCTSTM WND DMG3 E Pleasant HillPolk, IAReport from mPING: 1-inch tree limbs broken; Shingles blown off.
10:08 UTCTSTM WND DMG3 E Pleasant HillPolk, IAReport from mPING: 1-inch tree limbs broken; Shingles blown off.
10:13 UTCTSTM WND GST 601 W Webster CityHamilton, IA
10:13 UTCTSTM WND GST 601 W Webster CityHamilton, IA
10:15 UTCTSTM WND DMG6 N EllsworthHamilton, IADelayed report of semis tipped over on I35 near mile marker 139, along with power line damage. Time estimated from radar.
10:15 UTCTSTM WND DMG6 N EllsworthHamilton, IADelayed report of semis tipped over on I35 near mile marker 139, along with power line damage. Time estimated from radar.
10:20 UTCTSTM WND GST 75MingoJasper, IAWinds estimated 70 to 80 from Sheriff deputy.
10:20 UTCTSTM WND GST 75MingoJasper, IAWinds estimated 70 to 80 from Sheriff deputy.
10:22 UTCTSTM WND GST 683 E ColfaxJasper, IAPersonal weather station.
10:22 UTCTSTM WND GST 683 E ColfaxJasper, IAPersonal weather station.
10:22 UTCHAIL 1.5Prairie CityJasper, IAPing pong hail briefly fell followed by winds. Time estimated with radar.
10:22 UTCHAIL 1.5Prairie CityJasper, IAPing pong hail briefly fell followed by winds. Time estimated with radar.
10:26 UTCTSTM WND DMGPrairie CityJasper, IAPowerlines and trees down. Campers flipped. Time estimated with radar.
10:26 UTCTSTM WND DMGPrairie CityJasper, IAPowerlines and trees down. Campers flipped. Time estimated with radar.

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 IowaEvery tornado in Iowa since 1950Warnings in force in Iowa nowThe forecast where you are

The other tornadoes of May 24, 2024

42 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
May 241:08 AM CDTEF1Platte, NE11.8700
May 241:13 AM CDTEF1Platte, NE1.350
May 241:30 AM CDTEF1Colfax, NE4.8400
May 241:43 AM CDTEF0Seward, NE0.020
May 241:50 AM CDTEF0Dodge, NE1.175
May 242:03 AM CDTEF0Saunders, NE0.120
May 242:12 AM CDTEF0Saunders, NE0.160
May 242:18 AM CDTEF0Washington, NE3.460
May 242:18 AM CDTEF0Washington, NE1.860
May 242:25 AM CDTEF0Sarpy, NE0.150
May 242:32 AM CDTEF0Sarpy, NE0.560
May 242:35 AM CDTEF0Sarpy, NE3.7300
May 242:41 AM CDTEF1Harrison, IA0.7150
May 243:00 AM CDTEF0Pottawattamie, IA0.360
May 243:08 AM CDTEF1Sevier, AR8.2300$500,000
May 243:10 AM CDTEF0Montgomery, IA2.160
May 243:13 AM CDTEF0Shelby, IA0.140
May 243:22 AM CDTEF0Montgomery, IA1.230
May 244:38 AM CDTEF0Dallas, IA9.280$60,000
May 244:53 AM CDTEF0Polk, IA3.2100$50,000
May 244:57 AM CDTEF0Warren, IA2.250$2,000
May 245:07 AM CDTEF0Polk, IA1.550$90,000
May 245:10 AM CDTEF1Hamilton, IA2.975$80,000
May 245:56 AM CDTEF1Keokuk, IA7.270
May 246:26 AM CDTEF1Washington, IA18.3100
May 246:45 AM CDTEF1Washington, IA22.5150
May 246:55 AM CDTEF1Muscatine, IA15.075
May 247:12 AM CDTEF0Johnson, IA0.150
May 247:20 AM CDTUnratedCedar, IA11.010
May 247:30 AM CDTEF1Cedar, IA15.050
May 247:36 AM CDTUnratedScott, IA0.110
May 247:45 AM CDTEF1Scott, IA15.350
May 247:52 AM CDTEF1Rock Island, IL20.250
May 247:52 AM CDTEF1Scott, IA7.250
May 248:09 AM CDTUnratedScott, IA0.810
May 248:21 AM CDTUnratedClinton, IA0.310
May 248:50 AM CDTUnratedHenry, IL0.310
May 249:12 AM CDTUnratedWhiteside, IL1.010
May 249:31 AM CDTUnratedBureau, IL0.510
May 242:52 PM CDTUnratedRichland, ND0.510
May 245:24 PM EDTEF1Onslow, NC8.8150
May 247:05 PM CDTEF1Bowie, TX1.8275

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.