EF1 tornado in Ottawa County, Oklahoma

This is the first segment of a two segment tornado. In Ottawa County, Oklahoma, this tornado damaged several houses, damaged barns and outbuildings, and snapped or uprooted a number of trees. Based on this damage, maximum estimated wind in the tornado was 100 to 110 mph. The tornado moved in an easterly direction for much of its life cycle but turned more to the northeast as it approached the state line. It continued into Newton County, Missouri, and dissipated on the south side of the town of Seneca.

Severe thunderstorms developed along a nearly stationary frontal boundary over central Oklahoma during the early afternoon hours of the 20th. Very unstable air combined with strong low-level and deep-layer shear resulted in long-lived supercells forming over central Oklahoma and moving eastward into eastern Oklahoma. Several tornadoes occurred from these storms across Osage, Washington, and Nowata Counties. The storms organized into bow echos and line segments over eastern Oklahoma, from which several other tornadoes developed during the early evening hours across Ottawa, Adair, and Le Flore Counties. Damaging wind and large hail was also widespread across the region from these storms.