EF0 Tornado — Big Horn, Wyoming

2017-06-12 · near Winchester, Big Horn, Wyoming

Event narrative

A supercell thunderstorm dropped a weak rope tornado that moved slowly northward in southern Big Horn County and skipped along around a 3 mile path. The tornado remained over open country and caused no damage.

Wider weather episode

A combination of an abnormally strong upper level low, strong jet dynamics and an approaching cold front produced one of the biggest severe weather outbreaks across western and central Wyoming in many years. A total of 4 tornadoes were confirmed, including an EF2 tornado which was the strongest tornado that occurred in the NWS Riverton county warning area since 2001 which completely destroyed a trailer and threw it's base over 200 yards. There were also multiple reports of large hail, especially in Johnson County where hail up to tennis ball size was reported. In the dry slot across central and southern Wyoming, strong mid level winds mixed to the surface. The strongest winds were in the Lander foothills where wind gusts up to 76 mph occurred. Many trees were uprooted with some damage to outbuildings. Wind gusts 58 mph or over were also reported in Sweetwater County.

View location on OpenStreetMap → (44.1700, -108.4200)

Source: NOAA Storm Events Database, event_id 698417. Narrative written by the NWS forecast office that issued the report.