2018 Labor Day Tornado Genesis

A September 3, 2018 Labor Day isolated severe storm cell produced two quick tornadoes in Iowa. The following images show the tornado genesis as it progressed from my spotting position in Linn County. Above, the cell moves east (left) at 5:17 pm CDT after having produced a previous twister west of Alburnett, Iowa. An inflow cloud feeds into the base of the storm like a counter-clockwise wheel. The camera looks southwest from Central City Road and Sutton Road, about 2.3 miles WSW of Central City.

5:35 pm. Looking SW from Central City Road and Sutton Road. The inflow cloud at lower right has the appearance of frozen black water.

5:36 pm. Looking SSW. A lowering forms under a striated rotating cloud as it moves right-to-left in the image. Dangerous CG lightning was occurring at this time.

5:40 pm. The leading edge of the storm has now almost reached Sutton Road (background left). Note the appearance of a clear slot at background center.

5:42 pm. My position has now been moved to Sutton Road, about .22-mile south of Central City Road. Camera looks SSW at funnel moving right-to-left (west-to-east) in the image.

5:43 pm. Touchdown. Funnel has now become a tornado. Tornado is about .6-mile distant. It remained on the ground for no more than 30 seconds. Note the rain band circulation on the ground around the tornado. Nikon D7200 DSLR camera.