EF1 tornado in Osage County, Oklahoma

This is the second segment of a three segment tornado. The tornado crossed into Osage County over Keystone Lake and quickly crossed Highway 412. It then moved through a wooded area that was inaccessible by road. The first damage that was accessible by the survey team was at S 209th W Avenue, where the tornado damaged a church, snapped large tree limbs, and damaged a home. It moved east-southeast toward W Archer Road snapping or uprooting trees and damaging homes. Based on this damage, maximum estimated wind in this segment of the tornado was 95 to 105 mph. The tornado continued into Tulsa County, Oklahoma.

Severe thunderstorms developed during the afternoon hours to the east of a surface low pressure system located over southwestern Oklahoma and near a stationary frontal boundary that was draped across northeastern Oklahoma. Several of these storms developed supercell characteristics due to a very unstable air mass that was in place over the region coupled with strong vertical wind shear. These supercells produced several tornadoes, including a strong tornado that resulted in a fatality in Sand Springs. The storms also produced hail up to softball size and wind gusts to around 90 mph.

The storms evolved into a line during the evening hours and moved swiftly across eastern Oklahoma producing wind damage and hail to golfball size.

Locally heavy rainfall as a result of storms moving repeatedly across the same locations resulted in flash flooding. Two flash flood fatalities occurred in Muskogee County when a vehicle was driven into flood waters and was swept off the road.