EF0 tornado, Butterfield to Butternut, Minnesota, May 8, 2014

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 8, 2014

Touchdown

5:09 PM CDT (22:09 UTC)

Lifted

5:13 PM CDT (22:13 UTC)

On the ground

4 minutes

Path length

2.1 miles (3.4 km)

Path width

50 yards (46 m)

Deaths

0

Injuries

0

Property damage

$1,000

Counties

Watonwan, Blue Earth and Brown counties

Touchdown point

44.107, -94.379

Lift-off point

44.126, -94.345

Record number

1405081609-01

8 damage points were recorded along this path by NWS MPX, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF0.

• Tornado Begin. No Survey. Weak tornado near Madelia.
• No survey, point along county line.
• No Survey. Point along county line.

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

Several rounds of thunderstorms occurred Thursday afternoon and evening as warm air surged northward across the Plains, and into the Upper Midwest. A warm front extended across far southern Minnesota. Two tornadoes formed along this front near St. James and Butternut, and moved northeast across parts of Watonwan and Blue Earth Counties. Another complex of severe thunderstorms developed near Waseca, and moved northeast across the southern Metro area, and into west central Wisconsin. Several reports of damaging winds occurred with this bow type thunderstorm complex Thursday afternoon.

Tornado was witnessed and filmed my multiple storm chasers. It moved across open fields and caused no damage.

A trained spotter reported a tornado touching down briefly in an open field in extreme northeastern Watonwan County before it moved into extreme southeastern Brown County and then Blue Earth County. The tornado was videotaped by a storm chaser when it was in Blue Earth County.

A tornado touched down in the extreme northeastern corner of Watonwan County before crossing the extreme southeast corner of Brown County. It continued into Blue Earth County. During its time crossing Brown County, it crossed open fields. The tornado was caught on video by a storm chaser when it was in Blue Earth County.

A tornado originated in extreme northeastern Watonwan County and traversed across extreme southeastern Brown County before moving into Blue Earth County. It was filmed by a storm chaser during its time in Blue Earth County. The tornado hit a farm and damaged the roofs of some hog barns and then dissipated.

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

14 minutes of warning. NWS MPX issued a tornado warning for this county at 21:55 UTC, 14 minutes before the tornado touched down, in force until 22:11 UTC.

The county was under a tornado watch, issued at 18:47 UTC and running to 00:23 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 Moderate 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 20:03 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.

The Minneapolis radar (KMPX), 103 km away, was scanning. The volume nearest the touchdown began at 22:09 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 2014 tornado in MinnesotaEvery tornado in Minnesota since 1950Warnings in force in Minnesota nowThe forecast where you are

7 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.