Alto is a section of clouds along side that of nimbus. Alto Clouds are known as altostratus and altocumulus clouds which have a medium altitude from sea level.Altostratus clouds-Sheets of grey or blue clouds, where the sun or moon may appear to be behind frosted class.here is no alto cirrus cloud. The ten major cloud types are: Cirrus (high, wispy clouds. Look feathery) Cirrocumulus (high lumpy clouds) Cirrostratus (high sheety clouds w … ith a halo around the sun.