Tornadoes · United States · Iowa · 2024

EF2 tornado, Mt Hamill to Toolesboro, Iowa, April 16, 2024

From Mt Hamill to Toolesboro, this EF2 tornado ran 41.7 miles across Lee, Henry, Des Moines and Louisa counties on April 16, 2024, touching down at 4:25 PM CDT and reaching 600 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.

  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 mph

    Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.

  3. EF2111 to 135 mphthis tornado

    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
EF2
Date
April 16, 2024
Touchdown
4:25 PM CDT (21:25 UTC)
Lifted
5:21 PM CDT (22:21 UTC)
On the ground
56 minutes
Path length
41.7 miles (67.0 km)
Path width
600 yards (549 m)
Deaths
0
Injuries
0
Counties
Lee, Henry, Des Moines and Louisa counties
Touchdown point
40.770, -91.640
Lift-off point
41.160, -91.040
Record number
2404161525-01

The damage survey

32 damage points were recorded along this path by NWS DVN, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF2. The highest wind the damage implies is 125 mph.

  • Public video of a tornado southeast of Morning Sun.

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

Eastern Iowa, northwest Illinois, and far northeast Missouri sat in the warm sector of an intense Spring storm system that brought widespread severe thunderstorms to the area during the afternoon and evening hours on April 16th. There were reports of hail, damaging winds, and two tornadoes. One of the tornadoes was on the ground for 42 miles across parts of Lee, Henry, Des Moines and Louisa Counties and was rated EF-2 with maximum winds of 130 MPH.

An NWS survey team confirmed a long-track EF2 tornado Tuesday afternoon in southeast Iowa. The tornado developed just southwest of Houghton, Iowa in Lee County. The tornado caused mainly EF-1 damage in Lee county to hardwood trees and farm outbuildings. Significant damage to homes, trees, and outbuildings was observed. The worst damage occurred at a farmstead north of New London in Henry County, where the roof was removed from a brick house, one of the exterior walls collapsed, and the garage was destroyed. Numerous out buildings were also destroyed at nearby farmsteads. Maximum winds were estimated around 130 mph. The tornado continued into northwest Des Moines County and caused additional damage at several farmsteads southeast of Yarmouth. Public video confirmed that the tornado continued northeast into Louisa County, where a vehicle was blown off the road just east of Morning Sun. The tornado then damaged trees near the Port Louisa National Wildlife refuge, and finally lifted near the confluence of the Iowa and Mississippi Rivers. The tornado had a maximum path width around 600 yards. The tornado path length was around 42 miles. There were no injuries. Numerous emergency managers provided valuable assistance to NWS Quad Cities during the survey.

An NWS survey team confirmed a long-track EF2 tornado Tuesday afternoon in southeast Iowa. The tornado developed just southwest of Houghton, Iowa in Lee County. Significant damage to homes, trees, and outbuildings was observed. The worst damage occurred at a farmstead north of New London in Henry County, where the roof was removed from a brick house, one of the exterior walls collapsed, and the garage was destroyed. Numerous out buildings were also destroyed at nearby farmsteads. Maximum winds were estimated around 130 mph. The tornado continued into northwest Des Moines County and caused additional damage at several farmsteads southeast of Yarmouth. Public video confirmed that the tornado continued northeast into Louisa County, where a vehicle was blown off the road just east of Morning Sun. The tornado then damaged trees near the Port Louisa National Wildlife refuge, and finally lifted near the confluence of the Iowa and Mississippi Rivers. The tornado had a maximum path width around 600 yards. The tornado path length was around 42 miles. There were no injuries. Numerous emergency managers provided valuable assistance to NWS Quad Cities during the survey.

An NWS survey team confirmed a long-track EF2 tornado Tuesday afternoon in southeast Iowa. The tornado developed just southwest of Houghton, Iowa in Lee County. Significant damage to homes, trees, and outbuildings was observed. The worst damage occurred at a farmstead north of New London in Henry County, where the roof was removed from a brick house, one of the exterior walls collapsed, and the garage was destroyed. Numerous out buildings were also destroyed at nearby farmsteads. Maximum winds were estimated around 130 mph. The tornado continued into northwest Des Moines County and caused additional damage at several farmsteads southeast of Yarmouth. Public video confirmed that the tornado continued northeast into Louisa County, where a vehicle was blown off the road just east of Morning Sun. The tornado then damaged trees near the Port Louisa National Wildlife refuge, and finally lifted near the confluence of the Iowa and Mississippi Rivers. The tornado had a maximum path width around 600 yards. The tornado path length was around 42 miles. There were no injuries. Numerous emergency managers provided valuable assistance to NWS Quad Cities during the survey.

An NWS survey team confirmed a long-track EF2 tornado Tuesday afternoon in southeast Iowa. The tornado developed just southwest of Houghton, Iowa in Lee County. Significant damage to homes, trees, and outbuildings was observed. The worst damage occurred at a farmstead north of New London in Henry County, where the roof was removed from a brick house, one of the exterior walls collapsed, and the garage was destroyed. Numerous out buildings were also destroyed at nearby farmsteads. Maximum winds were estimated around 130 mph. The tornado continued into northwest Des Moines County and caused additional damage at several farmsteads southeast of Yarmouth. Public video confirmed that the tornado continued northeast into Louisa County, where a vehicle was blown off the road just east of Morning Sun. The tornado then damaged trees near the Port Louisa National Wildlife refuge, and finally lifted near the confluence of the Iowa and Mississippi Rivers. The tornado had a maximum path width around 600 yards. The tornado path length was around 42 miles. There were no injuries. Numerous emergency managers provided valuable assistance to NWS Quad Cities during the survey.

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

The warnings

12 minutes of warning. NWS DVN issued a tornado warning for this county at 21:13 UTC, 12 minutes before the tornado touched down, in force until 21:39 UTC.

The county was under a tornado watch, issued at 17:06 UTC and running to 00:33 UTC.

Issued (UTC)ExpiredProductOffice
16:47 UTC17:30 UTCSevere Thunderstorm WarningDVN
17:06 UTC00:33 UTCTornado WatchDVN
18:14 UTC19:00 UTCSevere Thunderstorm WarningDVN
21:13 UTC21:39 UTCTornado WarningDVN
21:54 UTC22:45 UTCTornado WarningDVN
22:46 UTC22:58 UTCSevere Thunderstorm WarningDVN

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 0.10 chance of a tornado within 25 miles, in the hatched area where significant tornadoes were expected. 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 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.

Davenport, (KDVN), 12:00Z

9.4 hours before the tornado, 101 km from the path. April 16, 2024.

Skew-T log-pSkew-T log-p diagram, Davenport, at 12:00Z on 2024-04-16Temperature 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 -94180, lifted condensation level 1439 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, Davenport, at 12:00Z on 2024-04-16The 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 392 square meters per square second, 0 to 6 km bulk shear 39 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
-94180 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
1439 m above ground
0-6 km bulk shear
39 kt
0-1 km bulk shear
29 kt
0-1 km storm-relative helicity
392 m²/s²
0-3 km storm-relative helicity
424 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.4
0-3 km lapse rate
3.6 K/km

Open this sounding in Storm Lab

The radar

The Quad Cities radar (KDVN), 96 km away, was scanning. The volume nearest the touchdown began at 21:27 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)ReportWhereCountyRemark
20:18 UTCTSTM WND GST 58EldonWapello, IA
20:18 UTCTSTM WND GST 58EldonWapello, IA
20:55 UTCHAIL 0.25BirminghamVan Buren, IA
21:03 UTCHAIL 1Mount SterlingVan Buren, IA
21:10 UTCTSTM WND GST 604 Ene Mount SterlingVan Buren, IAStraight line winds estimated at least 60 mph. Also reported half inch hail.
21:11 UTCTSTM WND DMG1 S BonaparteVan Buren, IATree branches down.
21:20 UTCHAIL 0.7RiversideWashington, IAdime sized hail right now.
21:34 UTCTORNADO4 E SalemHenry, IACorrects previous tornado report from 4 E Salem. A storm spotter was following storm and came across major house damage near Jewell Ave/Salem Rd or east of 218 on Salem Road. No injuries at this time. Time is estimated b
22:04 UTCTSTM WND DMG2 Se YarmouthDes Moines, IAReport from mPING: Trees uprooted or snapped; Roof blown off.
22:14 UTCTSTM WND DMGAmberLouisa, IATree branches down.
22:18 UTCHAIL 11 S West PointLee, IAReport from mPING: Quarter (1.00 in.).
22:20 UTCHAIL 12 Ese DavenportScott, IADime to Quarters near Vanderveer Park, delayed report.
22:45 UTCHAIL 0.251 Sse BeaverdaleDes Moines, IABeaverdale Rd near U.S. 34 becoming covered with pea sized hail.
22:46 UTCHAIL 0.52 Se SperryDes Moines, IAReport from mPING: Half-inch (0.50 in.).
22:47 UTCHAIL 1.252 E West BurlingtonDes Moines, IAPhoto from spotter. Time estimated.
22:48 UTCHAIL 0.51 E West BurlingtonDes Moines, IAReport from mPING: Half-inch (0.50 in.).
22:49 UTCHAIL 1West BurlingtonDes Moines, IA
22:50 UTCHAIL 0.255 Se SperryDes Moines, IA
22:51 UTCHAIL 0.88SalemHenry, IAOccurring right now.
23:14 UTCTSTM WND GST 503 Ene Spring LakeScott, IAAlso half inch hail.
23:15 UTCRAIN 0.995 Se SperryDes Moines, IA
23:20 UTCHAIL 12 Ese DavenportScott, IACorrects previous hail report from 2 ESE Davenport. Dime to Quarters near Vanderveer Park, delayed report.
23:23 UTCHAIL 0.71 N DavenportScott, IAReport from mPING: Dime (0.70 in.).
23:29 UTCTSTM WND GST 502 Nne Credit IslandScott, IAAlso pea sized hail.
23:30 UTCHAIL 0.52 Nw BuffaloScott, IA
23:36 UTCHAIL 0.881 Nnw Fort MadisonLee, IASocial media photo of hail. Delayed report. Time estimated.
00:09 UTCTSTM WND GST 581 S Burlington RegionalDes Moines, IAASOS station KBRL Burlington Arpt.

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 April 16, 2024

30 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
April 161:53 AM CDTEF0Smith, KS6.835$2,000
April 162:28 AM CDTEF0Webster, NE0.830
April 164:21 AM CDTEF1Greenwood, KS7.5200
April 165:51 AM CDTEF1Osage, KS3.5100
April 166:06 AM CDTEF1Osage, KS12.8752
April 167:34 AM CDTEF2Greenwood, KS2.7116
April 168:50 AM CDTEF0Nodaway, MO3.450
April 169:00 AM CDTEF1Nodaway, MO0.650
April 169:12 AM CDTEF0Taylor, IA2.650$5,000
April 169:31 AM CDTEF0Adams, IA2.450$15,000
April 169:58 AM CDTEF1Cass, IA0.930$25,000
April 1610:13 AM CDTEF1Clay, MO2.450
April 1611:05 AM CDTEF0Dallas, IA7.060$20,000
April 1611:35 AM CDTEF0Platte, NE8.450
April 1612:37 PM CDTEF0Platte, NE2.930
April 161:18 PM CDTEF0Colfax, NE1.130
April 161:39 PM CDTEF0Colfax, NE5.240
April 161:46 PM CDTUnratedPlymouth, IA0.010
April 161:48 PM CDTUnratedPlymouth, IA0.010
April 162:00 PM CDTEF1Plymouth, IA1.325
April 162:11 PM CDTUnratedSioux, IA0.010
April 162:26 PM CDTEF1Calhoun, IA5.275$12,000
April 162:27 PM CDTEF0Sioux, IA0.925
April 162:30 PM CDTEF0Sioux, IA0.325
April 162:57 PM CDTUnratedCalhoun, IA0.630
April 162:58 PM CDTEF1Lyon, IA1.075
April 163:02 PM CDTEF1Buchanan, IA10.0125
April 163:11 PM CDTEF0Pocahontas, IA1.775$200
April 163:32 PM CDTUnratedPocahontas, IA1.475
April 163:41 PM CDTEF0Pocahontas, IA0.640$10,000

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.