Cumulonimbus capillatus

A cumulonimbus capillatus is a cumulonimbus cloud with dense cirrus clouds above it, making the cloud top appear to contain hair-like structures. The name comes from the Latin word capillatus, meaning "with hair".^[1]

Cumulonimbus capillatus
Abbreviation	Cb cap.
Symbol
Altitude	Ground to 23,000 m (75,000 ft)
Appearance	Dark-based storm cloud capable of impressive vertical growth, with a fibrous upper portion
Precipitation	Very often rain, snow, snow pellets, or hail; heavy at times

It is an intermediate stage between cumulonimbus calvus and cumulonimbus incus.

Hazards

A cumulonimbus capillatus is a mature and powerful cumulonimbus cloud and can produce multiple severe weather.

• Lightning; this is a strong thunderstorm cloud and it is capable of producing bursts of cloud to ground and cloud to cloud lightning.
• Hail; hailstones may fall from this cloud if it is in a highly unstable environment (which favors a more vigorous storm updraft).
• Heavy rain; the cloud may drop several inches of rain in a short amount of time. This can cause flash flooding.
• Strong wind; gale-force winds from a downburst may occur under this cloud.
• Strong to weak tornado can occur.