Encroaching Outflow

Although the thin line of advancing thundershowers

in Cedar Rapids, Iowa was relatively weak just before 6:30 AM on Thursday, June 2, 2011, it produced many visual examples of outflow turbulence that were worth photographing. In this image looking south on Brentwood Drive NE, the leading edge of the cold air (dark cumulus) is colliding with warm air as it moves right-to-left, creating a ripple formation ahead of it. The spectacle was short lived as the sky soon became flat gray, and rain and lightning ensued within minutes.