Caught Napping

Literally. I was watching the Texans/Cardinals NFL preseason game on Sunday afternoon, August 28, 2016 when I dozed off. Weather forecasts had been benign: the SPC had a virtual no risk for Eastern Iowa, and I had lazily monitored garden variety cells drifting around the Cedar Rapids area an hour or so before. Sometime before 4:30, my better half verbally woke me amid the sounds of a siren saying there was a tornado warning for Linn County. What?? I know I was only half awake, but this sounded impossible! After I gathered my wits about me it was time to gather my gear and head north. A tornado was spotted on the ground near Troy Mills in northern Linn County at 4:33 pm. Tornadoes at this time of the year are almost always weak and short-lived, so I had no illusions about catching up to this one while it was still on the ground. My objective was to capture cloud structure, and I believe I at least achieved that. The above image shows my vehicle eastbound on Boyson Road in Marion, about .3-mile west of 10th Street at 4:46 pm. The cell at left is located about 18 miles to the NNE, near Coggon, and the cell at right to the northeast, about 35 miles distant near Cascade.

4:52 pm. Looking northeast from the intersection of 29th Avenue and Highway 13 in Marion.

4:55 pm. Northbound on Highway 13, about a half-mile south of County Home Road.

4:57 pm. Eastbound on County Home Road, about a half-mile east of Highway 13. It was about this time that the storm had weakened and the tornado warning was soon to be removed by the NWS. Too late for me! Nikon D7200 DSLR camera.

Above is a progression of radar screen captures from 4:10-4:50 pm, showing the evolution of the cell.
Besides materializing out of "nowhere," this storm was also curious by the fact that it was nearly devoid of all electrical activity and energized by a moisture-laden outflow boundary.