National Weather Service United States Department of Commerce



Severe thunderstorms developed across Iowa, Illinois and Missouri on Sunday, June 20th. Early in the morning, an MCS from the night before moved into our area along a stationary boundary and brought widespread rain showers to the area. This died off early in the day and then some clear skies moved in, providing some surface heating ahead of an approaching cold front. Ahead of this front, several discrete supercell thunderstorms formed, which posed a threat for tornadoes, hail, and severe wind gusts. Later in the day. these supercells generally grew upscale into a line of thunderstorms with embedded supercell structures. A tornado was spotted near Bernard, Iowa and lead to some damage to trees and farm outbuildings. Otherwise, severe winds reports and a few hail reports resulted from these storms. The severe threat continued on after our area heavily impacted some suburbs near Chicago. Please see NWS Chicago's webpage for more information.


Surrounding Office Summaries

Tornado near Bernard, Iowa. (Courtesy Sabra Lyons)