Weather Clouds Flashcards
Cirrocumulus
CC
High level (16,000’ to 40,000’), ice crystals small amount of liquid water, white, patchy sheets with ripples or tufts without gray shading
Form as part of a short-lived transitionary phase within an area of cirrus clouds and can also form briefly as a result of the breaking up of part of a cumulonimbus anvil.
Cirrostratus
CS
High-level, sheet-like, ice crystals, transparent, white veil.
May signal approach of a warm front if covers the sky. Indicates moisture at high altitudes.
Altocumulus
AC
Mid-height (6,500’ to 20,000’), globular masses or rolls in layers or patches, white or grey, signifies convection
Towering altocumulus, known as altocumulus castellanus, frequently signals the development of thunderstorms later in the day, as it shows instability and convection in the middle levels of the troposphere, the area where towering cumulus clouds can turn into cumulonimbus. It is therefore one of three warning clouds often recorded by the aviation industry, the other two being towering cumulus and cumulonimbus.
Altocumulus lenticularis is formed by uplift usually associated with mountains.
Altostratus
AS
Middle altitude (6,500’ to 20,000’), sheet, grey to bluish-grey, can see the sun through it
Indicates precipitation: Rain possible in thickened clouds. Classification is changed to nimbostratus if rain becomes persistent.
Nimbostratus
NS
Low level (base below 6,500’), formless layer, dark grey, rain, thickness 1 mile
Occurs along a warm front or occluded front where the slowly rising warm air mass creates nimbostratus along with shallower stratus clouds producing less rain
Mutatus mother clouds: Nimbostratus can form due to the complete transformation of altocumulus, altostratus and stratocumulus.
Stratocumulus
SC
Low level (
Stratus
ST
Low level (
Cumulus
CU
Latin: mass or heap, accumulate, formed by rising thermals
Cirrus
CI
High level (>16,500) ice crystals, thin, wispy strands, white or light grey.
Latin: a ringlet or curling lock of hair.
Forms when water vapor undergoes deposition at altitudes above 16,500 ft in temperate regions and above 20,000 ft in tropical regions. It also forms from the outflow of tropical cyclones or the anvils of cumulonimbus cloud. Since cirrus clouds arrive in advance of the frontal system or tropical cyclone, it indicates that weather conditions may soon deteriorate. While it indicates the arrival of precipitation (rain), cirrus clouds only produce fall streaks (falling ice crystals that evaporate before landing on the ground).
These conditions commonly occur at the leading edge of a warm front.
https://en.m.wikipedia.org/wiki/Cirrus_cloud#
lenticularis
Lens shape
castellanus
Towering, or castle like
Nimbus
Precipitation, Rain cloud
Virga
Rain that doesn’t reach the ground.
Cumulonimbus
CB
