Convective Cumulus

This cumulus tower was located northeast of the town of Postville, in northeastern Iowa at 4:07 PM CDT on Sunday, May 17, 2015. The Storm Prediction Center (SPC) had earlier in the day posted an Enhanced Risk for this area, but downgraded it to Slight before this image was captured. The building at right background is a Cenex convenience store on West Tilden Street (US Highway 18).

The image above is the same cell as the top photo, but much farther away-about 23 miles distant in northern Allamakee County, Iowa. Time was 4:15 PM. The scene was viewed on US Highway 52  from about 2.6 miles SE of Postville. The structure of the storm cell reminded me very much of the atomic bomb test mushroom cloud photo taken during Operation Crossroads at Bikini Atoll in 1946.

This image was captured along US Highway 52 about a minute after the middle shot was taken. Nikon
D5000 DSLR camera.