Review cloud name roots - how the types are named

Shape/form
Altitude
Precipitating

Cloud types

Cirrus
Look: White, thin, wispy, often like streamers
Characteristics: Made of ice crystals; Tend to move rapidly with upper-level winds
Signals: Often seen in fair weather, typically do not mean much if alone


Cirrostratus
Look: White to light-gray, thin, uniform
Characteristics: Made of ice crystals, may make sky glary white, often can see sun or moon through them, also halo around sun or moon typically visible and may be only indication of their presence
Signals: May denote approaching storm system, especially if in winter and if followed by lower clouds


Cirrocumulus
Look: White, small puffs which appear close together since so high
Characteristics: Made of ice crystals, may be disorganized but often aligned in rows that look like ripples; Generally relatively rare
Signals: If isolated not very significant, but if widespread may indicate approaching weather system


Altocumulus
Look: Variable colors from white to gray, variable thickness
Characteristics: Almost all liquid, often organized into rows or bands; Gray bottoms and larger cell size distinguish from cirrocumulus
Signals: If persistent and widespread, along with other clouds good indication of approaching weather system


Altostratus
Look: Gray to gray-blue, covers all or almost all of sky with very little variation, variable thickness
Characteristics: Almost all liquid; Sun may appear dimly visible, "watery"; No halo around sun, no shadows on ground, darker grayness distinguish from cirrostratus
Signals: Typically form ahead of rainy weather systems


Nimbostratus
Look: Dark gray to pale blue, precipitating thus bottom is blurry
Characteristics: Liquid water; Cannot see sun
Signals: Obviously precipitating, but precipiation is widepread, fairly uniform, and not very heavy


Stratus
Look: Light to dark gray, uniform and widespread across sky
Characteristics: Liquid water; Low, may appear somewhat ragged, looks like fog or may be fog that has lifted
Signals: Indicative of low-level moisture; Occurs around disturbed weather systems, but may be insignificant like morning clouds that burn off later in the day


Stratocumulus
Look: White to gray, distinct structures and base (not homogeneous across sky)
Characteristics: Liquid water; Larger elements and lower than altostratus
Signals: More likely to occur after passing of storm system, or may be locally recurring event such as around some coasts certain times of year


Cumulus
Look: Light color, often with darker base; Typically flat bottom and rounded top with fairly sharp outline
Characteristics: Liquid water; Range from very small and shallow to rather large and precipitating
Signals: Small cumulus in afternoon indicate fair weather; In morning may indicate conditions conducive to showers later in the day; If increasing in size showers may be developing


Cumulonimbus
Look: Bright white to dark gray depending on whether on sunlit side or if sun is being blocked; Very deep, may have anvil top
Characteristics: Liquid at lower levels, top is ice; Grows from smaller cumulus through towering phase to eventually precipitating
Signals: Produces severe weather (lightning, hail, tornadoes, etc), though not in all cases