FORMATION - Classifications
Cumulus - Rising Air Currents
Stratus - Air Cooled below Saturation
without Vertical Movement
ALTITUDE - Classifications
HIGH - 20,00'+
Cirrus - Thin, Wispy, Ice Crystals, Form above 25,00'
Cirrocumulus - Thin, Patchy, Wave Pattern, Mackerel Sky, Uncommon, Form at 20,000-25,000'
Cirrostratus - Patchy Fine Veil, Form Sun & Moon Halos,
Form at 20,000-25,000'
MIDDLE - 10,000'
Altostratus - Dense, Grey, Water-Vapor,
Moon shines through (translucent)
Altocumulus - Patchy, Puffy Layers, Grey-White,
Water-Vapor
LOW - below 6,500'
Stratus - Low, Uniform Sheet, Grey, Base Above Ground,
Produce Drizzle, No Vertical Movement
Nimbostratus - Dark. Thick, Rain Clouds
Stratocumulus - Irregular, Puffy Layered, Grey,
Don't Produce Rain
TOWERING
Cumulonimbus - Tops to 80,000', Thunderheads,
 Violent Up-Drafts Produce Lightning & Tornadoes
Cumulus - Puffy, White, Form in Day, Disappear at Nite
DEFINITIONS
Alto - Prefix, High
Cumulus - Piled-Up, Accumulated
Fracto - Prefix, Fragmented, Wind-Blown
Nimbus - Rain
Stratus - Layered