F1 tornado, Rochelle, Wyoming, June 12, 2001

1. F040 to 72 mph

   Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.

2. F173 to 112 mphthis tornado

   Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.

3. F2113 to 157 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. F3158 to 206 mph

   Severe damage. Whole stories of well-built houses destroyed, large buildings badly damaged, trains overturned, trees debarked, heavy cars lifted and thrown.

5. F4207 to 260 mph

   Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.

6. F5261 to 318 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

F1

Date

June 12, 2001

Touchdown

2:35 PM MDT (20:35 UTC)

Path length

20.0 miles (32.2 km)

Path width

30 yards (27 m)

Deaths

0

Injuries

0

County

Weston County

Touchdown point

43.600, -104.970

Lift-off point

43.630, -104.600

Record number

246

This tornado developed over Rochelle in southwestern Weston County, moving northeast to 7 miles southeast of Clareton. No one continuously tracked this storm as spotters were focused on another tornado in the county at the same time. A plot of damage reports received does follow the track of the meso-cyclone of the parent thunderstorm. It is likely that this tornado displayed an "up and down" intermittent tendency like many of other storms in the area at this time. This storm did do damage when it encountered property. It tipped over a mobil home 7 miles northeast of Rochelle and another blown over 7 miles southeast of Clareton. This storm also damaged a barn roof and out buildings as well as breaking windows in a residence southeast of Clareton.

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

34 minutes of warning. NWS UNR issued a tornado warning for this county at 20:01 UTC, 34 minutes before the tornado touched down, in force until 20:45 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 20:41 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.

Belle Fourche (BFU), 64 km from the path, in the two hours either side.

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

The Rapid City radar (KUDX), 167 km away, was scanning. The volume nearest the touchdown began at 20:32 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.

The live radar over the trackEvery 2001 tornado in WyomingEvery tornado in Wyoming since 1950Warnings in force in Wyoming nowThe forecast where you are

35 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.