Mini Cloud Atlas
Sometimes mammatus clouds don't arise from a thunderstorm. In this case, a dense chunk of cirrostratus clouds developed pronounced bags of mammati, probably with internal motions and processes similar to those in thunderstorm anvils (which also are thick cirrostratus plumes). The technical name for mammatus clouds associated with a thunderstorm is cumulonimbus mammatus; so for consistency this should be cirrostratus mammatus. The metal dish is the old NSSL Doppler radar antenna, which for three decades transmitted and received some of the most valuable research data ever gathered in meteorology. It now resides as an outdoor exhibit a few hundred feet from its former domed home.
Norman OK (1 May 6) Looking NNW.