WW2010
University of Illinois

WW2010
 
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Online Guides
 
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> meteorology
 
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Meteorology
 
  introduction
 
  air masses, fronts
 
  clouds, precipitation
 
  el nino
 
  forces, winds
 
  hurricanes
 
  hydrologic cycle
 
  light, optics
 
  midlatitude cyclones
 
> severe storms
 
  weather forecasting

Severe Storms
 
  introduction
 
  dangers of t-storms
 
> types of t-storms
 
  tstorm components
 
  tornadoes
 
  modeling

Types of T-storms
 
  storm spectrum
 
  single cell storms
 
  multicell clusters
 
  multicell lines
 
> supercells

Supercells
 
> introduction
 
  on radar
 
  schematic diagrams
 
  features
 
  variations
 
  hp supercells
 
  lp supercells
 
  multicell to supercell
 
  tornadic supercell

User Interface
 
  graphics
> text

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Supercell Thunderstorms
thunderstorms with deep rotating updrafts

The last of the four major storm types is the supercell. We define a supercell as a thunderstorm with a deep rotating updraft (mesocyclone). In fact, the major difference between supercell and multicell storms is the element of rotation in supercells. As we shall see, circumstances keep some supercells from producing tornadoes, even with the presence of a mesocyclone.

[Image: supercell storm (57K)]
Photograph by: Moller

Even though it is the rarest of storm types, the supercell is the most dangerous because of the extreme weather generated. This storm was producing baseball hail east of Carnegie, Oklahoma, as it was photographed looking east from 30 miles. From right to left (south to north), we note the flanking line, main Cb, and downwind anvil above the precipitation area.

The flanking line of the supercell behaves differently than that of the multicell cluster storm, in that updraft elements usually merge into the main rotating updraft and then explode vertically, rather than develop into separate and competing thunderstorm cells. In effect, the flanking updrafts "feed" the supercell updraft, rather than compete with it.

In summary, supercells are extremely dangerous, but excellent warnings are possible once the storm has been properly identified. The demarcation between supercell and multicell storms is most important, obviously much more so than that between single cell and multicell storms, or between multicell and squall line storms. As mentioned earlier, it has been suggested that thunderstorms simply be classified as "supercells" and "ordinary" storms. A few supercells will have the updraft located on the leading southeast (or east) flank, as we shall see in the section, Supercell Variations.



Multicell Lines
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Credits and Acknowledgments for WW2010.
Department of Atmospheric Sciences (DAS) at
the University of Illinois at Urbana-Champaign.

on radar