EF1 tornado in Carbon County, Wyoming

A Quasi-Linear Convective System (QLCS) with an embedded supercell structure

developed across far SE Carbon County around 2:45pm on 6/6/2020, and moved

across western and northern portions of the Snowy Mountain Range. The overall

radar presentation of the co-located cyclonic rotation at the leading edge of

the reflectivity surge improved near 2:50-2:56pm per the radar scans from KCYS.

The first note of tree damage from the tornado occurred on Forest Service Road 115

(FS115) that ran west of the main Forest Service Road 100 (FS100) at an elevation

around 9200 feet. Sporadic softwood pine trees were uprooted along FS115 and fell to

the N/NW direction. The survey team continued north on FS100, and additional tree

branches and smaller pine trees were uprooted. Progressing farther north along FS100,

tree damage became more widespread and severe with degree of damage indicators increasing

as more snapped softwood pine trees were cataloged and noted. This portion of FS100

decreases in elevation and into a narrow localized valley along Turpin Creek to the north

and northwest. A vantage point at the south end of the valley, higher in elevation,

allowed for a landscape view towards the main tree damage path. This enhanced visual

perspective allowed the survey team to see east-northeast uprooted and bent

softwood pine trees. There were also snapped pine trees down the main center line of the damage path oriented to the north to north-northwest, and softwood pine trees to the east of the main centerline, converging back to the west to northwest. It was noted the greatest tree damage on the south to middle portions of the local Turpin Creek Valley. This damage was located along the west side of FS100, crossed FS100, with the greatest snapping to the East as one progressed farther north along FS100. This evidence indicated the tornado crossed FS100 in following the main snapping of tree damage along with the notable convergent pattern of tree fall. From the south side of the local Valley, tree damage extended at least 100-200 yards west of the road, with a wider damage swath noted to the east of FS100 as one progressed farther north. The damage swath of uprooted and snapped trees east of FS100 was approximately 200-300 yards from the road. The damage area narrowed substantially and became indiscernible as the team progressed north towards Bow River Campground near the intersection of FS100 and FS101. The end point was marked at the north end of a concentrated area of tree debris, small tree uprooting, and dislodged branches at an elevation around 9000 feet.

It should be noted that sporadic tree damage was also noted both southwest and northwest of the main track and the concentrated damage area. Sporadic softwood pine uprooting was noted along FS100 just north of HWY 130, but showed no conclusive evidence of a converging pattern. Likewise, FS105, FS120, and FS111 also had sporadic trees down, but once again, all trees fell in a northerly direction. The uniform direction suggested straight-line winds were the likely culprit of this tree damage.

Widespread derecho moved through the area producing severe and significant wind gusts and causing damage to numerous outbuildings and sheds. A QLCS tornado developed over the Snowy Range along this line of storms producing mostly tree damage that was rated EF-1.