This loop of GOES-8 10.7 micron IR imagery shows transverse cirrus bands forming along the northern periphery of a Mesoscale Convective System on 21 July 1998. These cirrus bands are often a satellite signature of high-altitude turbulence; some reports of moderate turbulence were received from aircraft flying at 33,000 to 39,000 feet across eastern South Dakota, southern Minnesota, and northwestern Wisconsin during the time period of this loop.