Tornado in Polk County, Nebraska

A brief touchdown occurred in rural northern Polk County, causing no damage. Location was approximated from radar data and a photo provided by a deputy.

A mesoscale convective system (MCS) brought locally damaging wind gusts and a brief tornado to portions of south central Nebraska during the late evening and overnight hours of August 13th. Thunderstorms developed over the central High Plains during the late afternoon and evening hours then shifted eastward into south central Nebraska, aided by a strong low level jet after 10PM. Some of this activity became severe, most notably a small bow echo that impacted areas generally between I-80 and Hwy 6 to the west-southwest of the Tri-Cities. Here, wind gusts of 60-65 MPH were estimated, and minor tree and outbuilding damage was reported. The bow echo weakened below severe levels prior to reaching the Highway 281 corridor just after midnight. However, another band of strong thunderstorms developed along a west-northwest to east-southeast axis along the warm air advection wing of the MCS and affected areas mainly N and NE of the Tri-Cities. Later, it was determined that a brief tornado touched down out of this activity in far northern Polk County, based on evidence from a law enforcement photo along with and radar data. No damage was reported, so the tornado was rated EF-U. Non-severe thunderstorm activity continued well into the overnight hours.