Cumulonimbus capillatus

Cumulonimbus capillatus
AbbreviationCb cap.
Symbol
AltitudeGround to 23,000 m
(75,000 ft)
AppearanceDark-based storm cloud capable of impressive vertical growth, with a fibrous upper portion
PrecipitationVery often rain, snow, snow pellets, or hail; heavy at times

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]

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.[2]

  • 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:[3] 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.
  • Weak to strong tornados can occur.

References

  1. ^ "capillatus". Oxford Reference. Oxford University Press. Retrieved 2021-10-18.
  2. ^ Korosec, Marko (2025-02-21). "Types of convective clouds – from fair-weather clouds to thunderstorms". Severe Weather Europe. Retrieved 2026-02-01.
  3. ^ "Cumulonimbus clouds". Met Office. Retrieved 2025-10-22.