Wall cloud

Wall cloud (Murus)
A wall cloud seen from Pikes Peak, Colorado on July 20, 2023.
AbbreviationCb mur.
Symbol
GenusCumulonimbus (heap, rain)
Species
  • Calvus
  • Capillatus
VarietyNone
Altitude500-16,000 m
(2,000-52,000 ft)
ClassificationFamily C (Low-level)
AppearanceA dark cloud feature that protrudes from the base of a cumulonimbus more popularly known as a wall cloud.
PrecipitationVery common nearby, but not under : Rain, Snow, Snow pellets or Hail, heavy at times

A wall cloud (murus[1] or pedestal cloud) is a large, localized, persistent, and often abrupt lowering of cloud that develops beneath the surrounding base of a cumulonimbus cloud and from which tornadoes sometimes form.[2] It is typically beneath the rain-free base (RFB)[3] portion of a thunderstorm, and indicates the area of the strongest updraft within a storm. Rotating wall clouds are an indication of a mesocyclone in a thunderstorm; most strong tornadoes form from these. Many wall clouds do rotate; however, some do not.[4][5]

  1. ^ Sutherland, Scott (March 23, 2017). "Cloud Atlas leaps into 21st century with 12 new cloud types". The Weather Network. Pelmorex Media. Retrieved 24 March 2017.
  2. ^ "Definition of Wall Cloud". A Comprehensive Glossary of Weather. Retrieved 2013-01-21.
  3. ^ Branick, Mike L. (1996). NOAA Technical Memorandum NWS SR-145: A Comprehensive Glossary of Weather Terms for Storm Spotters. National Weather Service. OCLC 39732655.
  4. ^ Branick, Mike L. (1996). NOAA Technical Memorandum NWS SR-145: A Comprehensive Glossary of Weather Terms for Storm Spotters. National Weather Service. OCLC 39732655.
  5. ^ Cite error: The named reference Training was invoked but never defined (see the help page).