Clouds

Appearance (texture)

Layered: develop horizontally ("strato")

Heaped: develop vertically ("cumulo")

Distance above ground

High-level: 23,000 feet and above ("cirro")

Mid-level: 6,500 to 23,000 feet ("alto")

Low-level: below 6,500 feet

Other characteristics

Includes rain or snow ("nimbo")

Cloud Graphic Source: Clouds | NWS

Cloud Images Sources: Ten Basic Clouds | NWS

Rain or snow comes from low-level clouds. Check the "Low-level" box on the side to see related clouds.

Cirrus

Wispy, feathery, and composed entirely of ice crystals. They often are the first sign of an approaching warm front or upper-level jet streak.

Cumulus

More cellular (individual) in nature, have flat bottoms and rounded tops, and grow vertically

Stratus

Uniform and flat, producing a gray layer of cloud cover which may be precipitation-free or may cause periods of light precipitation or drizzle

Cirrostratus

Form more of a widespread, veil-like layer (similar to what stratus clouds do in low levels)

Cirrocumulus

Layered clouds permeated with small cumuliform lumpiness. They also may line up in streets or rows of clouds across the sky denoting localized areas of ascent (cloud axes) and descent (cloud-free channels).

Altostratus

"Strato" type clouds that possess a flat and uniform type texture in the mid levels.

Altocumulus

Exhibit "cumulo" type characteristics (see below) in mid levels, i.e., heap-like clouds with convective elements.

Stratocumulus

Hybrids of layered stratus and cellular cumulus, i.e., individual cloud elements clumped together in a continuous distribution. Stratocumulus also can be thought of as a layer of cloud clumps with thick and thin areas.

Nimbostratus

Generally thick, dense stratus or stratocumulus clouds producing steady rain or snow

Cumulus congestus

A cumulus cloud that exhibits significant vertical development (but is not yet a thunderstorm)

Cumulonimbus

Thunderstorm producing heavy rain. In addition, cloud electrification occurs within cumulonimbus clouds due to many collisions between charged water droplet, graupel (ice-water mix), and ice crystals, resulting in lightning.