Mega Meso

This massive mesocyclone cloud, taking up a good portion of the sky, was not as visible to the eye as it is in this image. A 12-second exposure at f/8 and an ISO of 250 brought out details the eye had trouble discerning. Frequent lightning flashes provided the exposure's illumination. Getting a sharp image was a difficult proposition here, even with a tripod--sustained RFD winds of near 50 mph buffeted the cameraman. This 12 second exposure reveals a slight blur from the rotation of the storm structure, containing a lowering at left. The meso had produced a wedge tornado near Nemaha, Iowa about a half-hour earlier. This view, shot around 9:45 PM, Saturday, April 9, 2011, looks north from County Road D15, about 1.5 miles west of the town of Knoke, in northwest Iowa. The red lights in the background belong to a wind farm. The road leading off into the horizon and past a farm at left is County Road N33.