EF0 tornado, Amish to Windham, Iowa, March 31, 2023

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.

Rating

EF0

Date

March 31, 2023

Touchdown

4:37 PM CDT (21:37 UTC)

Lifted

4:46 PM CDT (21:46 UTC)

On the ground

9 minutes

Path length

6.1 miles (9.8 km)

Path width

50 yards (46 m)

Deaths

0

Injuries

0

County

Johnson County

Touchdown point

41.530, -91.790

Lift-off point

41.600, -91.720

Record number

2303311537-01

66 damage points were recorded along this path by NWS DVN, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF4. The highest wind the damage implies is 170 mph.

• House swept from foundation.
• 3 story farmhouse wiped away and spun with debris landing about 100 feet away. Car lofted about 1000 feet into field.
• Wall collapsed on home. Tree damage. Roof damage
• Lots of tree damage. Trees uprooted and snapped and limbs broken

Survey points are preliminary and are the raw material the published rating was built from. Source: NWS Damage Assessment Toolkit.

A very strong system developed on the morning of March 31st and tracked across the state of Iowa. This system pulled unseasonably warm and moist air into the Midwest, which combined with a very favorable wind profile to create a volatile environment for severe thunderstorms. Discrete supercell thunderstorms occurred initially, but quickly transitioned into a QLCS mode. This system produced a historic tornado outbreak for the area, with a record 29 tornadoes on the day, including 13 rated EF-2, 1 rated EF-3, and 1 rated EF-4. This was the first EF-4 tornado in the NWS Quad Cities service area since 1995. 11 injuries were reported, with no known fatalities. In addition to the numerous tornadoes, there were many large hail and damaging wind reports. Maximum straight line thunderstorm winds were estimated at 80 to 90 mph.

Another large, violent tornado developed in eastern Keokuk County as the initial tornado was weakening southwest of Keota. The tornado tracked to the northeast, on the western fringe of Keota, and crossed into Washington County near the intersection of Keokuk-Washington Road and 180th St. The tornado then continued through northwest Washington county, extreme southeast Iowa County, and into far southwest Johnson County. The tornado severely damaged several homes near Keota, wiping one house completely off its foundation, resulting in EF-4 level damage. A car was lofted in the air and tossed about 1000 feet into a nearby field and trees were completely debarked with only stubs of the largest branches remaining. As the tornado tracked west of Wellman, Iowa it knocked over a 325 ft cell phone tower. The tornado moved into extreme southeast Iowa County near the intersection of Iowa-Washington Road and Ginkgo Ave., and then into far southwest Johnson County, about a third of a mile north of the intersection of Iowa-Washington Road and Johnson Iowa Road SW. The tornado dissipated just northwest of Hillcrest Academy in Johnson County. The tornado was rated EF-4 in Keokuk County, EF-3 in Washington County, and EF-1 in Iowa and Johnson Counties.

A review of Sentinel satellite data confirms that a separate tornado developed near Amish, and moved northeast around 6 miles to near Frytown, before dissipating. The tornado caused damage to farm outbuildings along its path. The tornado was rated EF0 with maximum winds around 85 mph. After the tornado dissipated, the associated supercell thunderstorm cycled again and produced an EF2 tornado that tracked from Coralville to Solon.

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

32 minutes of warning. NWS DVN issued a tornado warning for this county at 21:05 UTC, 32 minutes before the tornado touched down, in force until 21:45 UTC.

The county was under a tornado watch, issued at 16:47 UTC and running to 23:35 UTC.

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 Storm Prediction Center had this point in a High Risk, with a 0.30 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 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.

Iowa City (IOW), 19 km from the path, in the two hours either side.

From the Iowa Environmental Mesonet's archive of airport observations.

The Quad Cities radar (KDVN), 98 km away, was scanning. The volume nearest the touchdown began at 21:39 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.

Local storm reports within 60 km of the path, in the three hours either side.

From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.

The live radar over the trackEvery 2023 tornado in IowaEvery tornado in Iowa since 1950Warnings in force in Iowa nowThe forecast where you are

126 more were confirmed in the United States that day.

All 127 of them

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.

NOAA Storm Prediction Center tornado database, 1950-2025, the official record kept by NOAA's Storm Prediction Center.