EF0 tornado, Dempster, South Dakota, May 30, 2022

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 30, 2022

Touchdown

2:30 PM CDT (19:30 UTC)

Lifted

2:31 PM CDT (19:31 UTC)

On the ground

1 minutes

Path length

0.7 miles (1.0 km)

Path width

10 yards (9 m)

Deaths

0

Injuries

0

County

Hamlin County

Touchdown point

44.632, -96.987

Lift-off point

44.637, -96.976

Record number

2205301330-01

32 damage points were recorded along this path by NWS ABR, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF2. The highest wind the damage implies is 115 mph.

• Shifted 15ft from original location
• Point moved to actual location, photo taken from a distance
• Flipped over, moved east 15-20ft
• Photos are mainly of distant objects.

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

Storms redeveloped in the late morning, with supercell characteristics across eastern South Dakota producing up to one inch diameter hail and winds of 70 mph, in addition to 6 confirmed tornadoes, one of which was rated EF3. Heavy rain also occurred with this system, with the greatest amount of rainfall measured by a CoCoRaHS observer being 4.69 inches measured near Columbia, and the highest COOP observer report coming out of Milbank with a two day total of 2.86. This heavy rain resulted in flooding in several rural locations but also included parts of Watertown and Aberdeen.

Eyewitness reported a brief tornado touchdown which did only minor damage to a cattle shed.

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.

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 0.15 chance of a tornado within 25 miles, in the hatched area where significant tornadoes were expected. The outlook in force was issued at 16:25 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.

Watertown (ATY), 34 km from the path, in the two hours either side.

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

The Sioux Falls radar (KFSD), 118 km away, was scanning. The volume nearest the touchdown began at 19:27 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.

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 2022 tornado in South DakotaEvery tornado in South Dakota since 1950Warnings in force in South Dakota nowThe forecast where you are

36 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.