Unrated tornado, Voorhies to Evansdale, Iowa, March 28, 2020

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 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. Unratedthis tornado

   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

Unrated

Date

March 28, 2020

Touchdown

5:39 PM CDT (22:39 UTC)

Lifted

5:42 PM CDT (22:42 UTC)

On the ground

3 minutes

Path length

2.3 miles (3.7 km)

Path width

40 yards (37 m)

Deaths

0

Injuries

0

County

Black Hawk County

Touchdown point

42.314, -92.469

Lift-off point

42.340, -92.440

Record number

2003281639-02

1 damage points were recorded along this path by NWS DMX, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF0. The highest wind the damage implies is 85 mph.

• Building was overturned with base structure remaining intact. Southern flank of building was open allowing wind to flow underneath and lift roof off, hence the EF0 rating.

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

Six tornadoes occurred across central Iowa during the afternoon. The tornadoes remained in rural areas with some damage to farm buildings and trees. No injuries or deaths were reported.

Picture of tornado near Voorhies was received from trained spotter. The path of the tornado was later discovered in high resolution satellite imagery and adjusted accordingly. The tornado remained in rural farm fields although passed very close to a house near the intersection of State Highway 175 and Highway 63, although no damage was reported. With no damage occurring to any damage indicators, the tornado was rated an EFU.

Tornado developed in rural farmland between Hudson and Waterloo moving quickly northeast. The tornado encountered an building site destroying a hay shelter building that was open on both sides. Additional damage occurred to a small storage building and trees on the site. All damage was rated EF0. The tornado continued northeast and dissipated before reaching Highway 20 on the south side of Waterloo.

Brief tornado was caught on video by a storm chaser. The chaser was located just south of the Highway 20 and Highway 218 intersection looking northward toward downtown Waterloo. The tornado occurred in an unpopulated area southeast of downtown near the Waterloo Waste Water Treatment Plant along the Cedar River. It is likely some tree damage occurred, however no reports were received, therefore the tornado was rated EFU.

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

No tornado warning for this county appears in the archive as in force at the moment the tornado touched down. One was issued for the county at another hour that day.

The county was under a tornado watch, issued at 19:45 UTC and running to 00:01 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 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 20:06 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.

Waterloo (ALO), 26 km from the path, in the two hours either side.

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

The Des Moines radar (KDMX), 124 km away, was scanning. The volume nearest the touchdown began at 22:39 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 2020 tornado in IowaEvery tornado in Iowa since 1950Warnings in force in Iowa nowThe forecast where you are

20 more were confirmed in the United States that day.

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.