WW2010
University of Illinois

WW2010
 
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Online Guides
 
  introduction
 
> meteorology
 
  remote sensing
 
  reading maps
 
  projects, activities

Meteorology
 
  introduction
 
  air masses, fronts
 
> clouds, precipitation
 
  el nino
 
  forces, winds
 
  hurricanes
 
  hydrologic cycle
 
  light, optics
 
  midlatitude cyclones
 
  severe storms
 
  weather forecasting

Clouds, Precipitation
 
  introduction
 
  development
 
> cloud types
 
  precipitation

Cloud Types
 
  introduction
 
  high-level clouds
 
  mid-level clouds
 
  low-level clouds
 
> vertically developed
 
  other cloud types

Vertically Developed
 
  fair wx cumulus
 
> cumulonimbus

User Interface
 
  graphics
> text

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Cumulonimbus Clouds
reaching high into the atmosphere

Cumulonimbus clouds (Cb) are much larger and more vertically developed than fair weather cumulus. They can exist as individual towers or form a line of towers called a squall line. Fueled by vigorous convective updrafts (sometimes in excess 50 knots), the tops of cumulonimbus clouds can easily reach 39,000 feet (12,000 meters) or higher.

[Image: example of cumulonimbus clouds (74K)]
Photograph by: NOAA

Lower levels of cumulonimbus clouds consist mostly of water droplets while at higher elevations, where temperatures are well below 0 degrees Celsius, ice crystals dominate. Under favorable atmospheric conditions, harmless fair weather cumulus clouds can quickly develop into large cumulonimbus clouds associated with powerful thunderstorms known as supercells.

[Image: example of supercell (77K)]
Photograph by: Knupp

Supercells are large thunderstorms with deep rotating updrafts and can have a lifetime of several hours. Supercells can produce frequent lightning, large hail, damaging winds, and tornadoes.

[Image: approaching cumulonimbus clouds at sunset (69K)]
Photograph by: Holle

These storms tend to develop during the afternoon and early evening when the effects of heating by the sun are strongest. For more information about supercells and other types of severe weather phenomena, visit the Severe Storm Spotters Guide.



fair wx cumulus
Terms for using data resources. CD-ROM available.
Credits and Acknowledgments for WW2010.
Department of Atmospheric Sciences (DAS) at
the University of Illinois at Urbana-Champaign.

Other Cloud Types