Basic Cloud Families

Family Midlatitude Characteristics of Cloud Names Comments
Elevation of Bases Family
High 12 km (36000 ft) Ice crystals. "Feathery." cirrus Fernlike
Halo arond sun or moon. cirrostratus Sheets
Jet stream levels. cirrocumulus Small lumps
Middle 6 km (18000 ft) Mostly water droplet. altostratus Thick sheets
Bases appear gray and altocumulus Large lumps
block out sun's light.
Low Sfc to 1 km (3000 ft) Water droplet (except stratus Cloud on the ground
nimbostratus, which may stratocumulus Same as stratus with some vertical growth
be stacked above freezing level) nimbostratus Multiple layers of stratiform clouds
Vertical Sfc to 2 km (6000 ft) Water droplets make up cumulus Width of base greater than height.
Development bottom portion (cauliflower cumulus congestus Height greater than width of base.
or whipped cream texture) cumulonimbus Anvil tops, lightning, rain, hail.
and ice crystals make up anvil top.