Ruth Quist (Member 49,516) saw a big splash in the sky over Charlo, Montana, US. This is an example of a mighty Cumulonimbus storm cloud that is dissipating and losing its power. The lower part of the cloud will likely shower itself away, leaving just a dense, white expanse of ice crystals at the top. This would be classed as a Cirrus spissatus cumulonimbogenitus, meaning it’s a high ice-crystal cloud that looks thick and that evolved from a Cumulonimbus. Trust an ostentatious Cumulonimbus storm cloud to make a splash even as it’s on its way out.