Meso 'n' Mammatus

This image, taken just before 4:00 PM on Sunday, May 22, 2011, shows three separate cloud types: Low to the ground in the foreground is fast moving cumulus scud. Resembling the top of a water tower at center is a pileus cloud or banding structure, the result of a strong updraft acting on a moist lower level air. The cloud, probably cumulonimbus congestus, was small but growing fast vertically--its top can be seen just above the dark cloud at right. Above everything else and spread across most of the sky were mammatus clouds, indicators of a high wind shear environment. This view looks northeast from the grounds at Noelridge Christian Church in Cedar Rapids, Iowa, one of my storm spotter locations which affords a great all-around view of the sky. Cedar Rapids was lucky this time as storm cells passed north and south of the city. Over-protective warning sirens sounded at this location twice before 3:00 PM--but no real suggestion of rotation over the city was evident. Despite ripe conditions for widespread tornadic formation in Eastern Iowa, only about four locations confirmed touchdowns.