EF0 tornado, Etna to Greenleafton, Iowa, May 27, 2019

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

May 27, 2019

Touchdown

1:49 PM CDT (18:49 UTC)

Lifted

1:58 PM CDT (18:58 UTC)

On the ground

9 minutes

Path length

6.2 miles (10.0 km)

Path width

30 yards (27 m)

Deaths

0

Injuries

0

Property damage

$202,000

Counties

Howard and Fillmore counties

Touchdown point

43.498, -92.260

Lift-off point

43.581, -92.212

Record number

1905271249-01

13 damage points were recorded along this path by NWS ARX, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF1. The highest wind the damage implies is 97 mph.

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

As an area of low pressure moved across the Upper Midwest, thunderstorms developed during the afternoon of Memorial Day (May 27th) across portions of southeast Minnesota. These storms quickly became severe and produced four tornadoes across Fillmore County. The first tornado moved into the southern part of the county from Iowa and damaged some farm buildings and trees along its path as it moved toward Greenleafton. The other three tornadoes were just brief touchdowns over the western portions of the county south and east of Spring Valley.

As an area of low pressure moved across the Upper Midwest, thunderstorms developed during the afternoon of Memorial Day (May 27th) across portions of northeast Iowa. These storms quickly became severe and produced tornadoes across Floyd, Chickasaw and Howard Counties. The first tornado developed near Charles City (Floyd County) and was on the ground for about 7 miles, extensively damaging some buildings at the Floyd County fairgrounds along damaging three houses severe enough to make them inhabitable. Another tornado moved across rural portions of Howard County for 12 miles and damaged a wind turbine and cattle barns. Two other weaker tornadoes also touched down across northwest Chickasaw County and northern Howard County very close to the Minnesota state line.

A brief tornado touched down in rural southwest Fillmore County south of Ostrander. The tornado flipped a farm shed over a tree line.

A tornado briefly touched down near Etna and uprooted some trees at a cemetery.

A tornado briefly touched down east of Spring Valley. A cattle barn was heavily damaged just north of County Highway 16.

A tornado formed over far northern Howard County north of Lime Springs before quickly moving across the state line into Fillmore County, Minnesota. This was the third tornado of the day in Howard County.

A tornado that developed just south of the Minnesota state line moved into Fillmore County south of York and then moved north-northeast before dissipating near Greenleafton. A small barn and machine shed was destroyed and another sustained roof damage from the tornado. Another two farms also sustained some minor damage to buildings and a few homes sustained minor wind and tree damage.

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

9 minutes of warning. NWS ARX issued a tornado warning for this county at 18:40 UTC, 9 minutes before the tornado touched down, in force until 19:00 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 General Thunderstorms Risk. The outlook in force was issued at 16:22 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.

Preston (Awos) (FKA), 16 km from the path, in the two hours either side.

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

The La Crosse radar (KARX), 90 km away, was scanning. The volume nearest the touchdown began at 18:45 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 2019 tornado in IowaEvery tornado in Iowa since 1950Warnings in force in Iowa nowThe forecast where you are

62 more were confirmed in the United States that day.

All 63 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.