EF1 tornado in Sublette County, Wyoming

A tornado touched down in open country north of Merna, Wyoming, and caused tree damage along its approximately 2.4 mile path. At its widest, the tornado produced sporadic tree damage approximately 300 yards across. The trees fell on some fence lines, but otherwise caused no property damage.

A thunderstorm rapidly developed near Merna, Wyoming, on the afternoon of Sunday, September 4. Southeast wind at the surface coupled with strong southwest flow aloft created a favorable environment in which the storm could rotate. The storm strengthened, began rotating, and moved north across several private ranches and spawned a funnel cloud. The funnel eventually touched down as a tornado and caused areas of considerable tree damage just below The Rim, between Merna and Hoback Ranches. Large, old growth aspen trees of 12 to 15 inches in diameter were snapped in half, and other trees were topped, twisted, and/or uprooted. Hail up to the size of ping pong balls also fell near The Rim during the height of the thunderstorm.