EF2 tornado, Lingle to Harrison, Wyoming, June 12, 2017

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 mphthis tornado

   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

EF2

Date

June 12, 2017

Touchdown

6:09 PM CDT (23:09 UTC)

Lifted

7:01 PM CDT (00:01 UTC)

On the ground

52 minutes

Path length

25.6 miles (41.1 km)

Path width

500 yards (457 m)

Deaths

0

Injuries

2

Property damage

$603,000

Counties

Goshen and Sioux counties

Touchdown point

42.276, -104.196

Lift-off point

42.583, -103.920

Record number

1706121709-01

2 damage points were recorded along this path by NWS CYS, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF2. The highest wind the damage implies is 130 mph.

• Large farm work and tool shop completely destroyed with debris blown several hundred yards.

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

One of the most significant severe weather episodes to affect southeast Wyoming and the western Nebraska Panhandle occurred on the afternoon and early evening of Monday 12 June 2017. Eleven confirmed tornadoes, hail to grapefruit size, and damaging winds were observed. Supercell thunderstorms developed during the early afternoon along Interstate 25 between Fort Collins, CO and Wheatland. Lifting northeast, these thunderstorms spread into the southeast Wyoming plains late in the afternoon and into the western Nebraska Panhandle during the evening. Two people suffered injuries with an EF-2 rated tornado north of Torrington near the Wyoming/Nebraska stateline.

One of the most significant severe weather episodes to affect the western Nebraska Panhandle occurred during in the early evening of Monday 12 June 2017. Several tornadoes, hail to baseball size, and damaging winds were observed. Supercell thunderstorms developed during the afternoon along Interstate 25 between Fort Collins, CO and Wheatland. Lifting northeast, these thunderstorms spread into the western Nebraska Panhandle during the early evening.

Significant tornado damage was noted at a ranch 20 miles north-northeast of Torrington, WY, just west of the Union Pacific railway line. Significant damage consistent with EF-2 intensity winds was to the main ranch residence and surrounding barns (DI 1, DOD 8). Several three-quarter ton pickup trucks were vaulted several yards by tornadic winds, with several horse trailers rolled 50 to 100 yards and severely damaged. Several horses at this location were seriously injured with 3 horses killed. One person in the residence received minor head injuries. The tornado continued northeast, moving into Sioux County, NE at 1630 MST.

A tornado crossed the WY/NE state line into Sioux County, NE at 1630 MST, and continued northeast before lifting west of Highway 29, 8 miles south-southwest of Harrison, NE at 1701 MST. Damage consistent with EF-2 intensity was noted by the survey team to the residence, as well as to surrounding trees and outbuildings (DI 2, DOD 6) 13 miles southwest of Harrison, NE. One resident at this location was treated and released at a local hospital with injuries incurred from flying debris in the home.

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

28 minutes of warning. NWS CYS issued a tornado warning for this county at 22:41 UTC, 28 minutes before the tornado touched down, in force until 23:15 UTC.

The county was under a tornado watch, issued at 19:11 UTC and running to 01:36 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 0.15 chance of a tornado within 25 miles, in the hatched area where significant tornadoes were expected. The outlook in force was issued at 20:00 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 Cheyenne radar (KCYS), 155 km away, was scanning. The volume nearest the touchdown began at 23:07 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 2017 tornado in WyomingEvery tornado in Wyoming since 1950Warnings in force in Wyoming 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.