WW2010
University of Illinois

WW2010
 
  welcome
 
> online guides
 
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  educational cd-rom
 
  current weather
 
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  index

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

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

Features
 
  overshooting tops
 
> rotating updrafts
 
  backlighting

User Interface
 
  graphics
> text

NOTE: We've guessed that you're not using a client that supports colored tables and have tried to compensate. Low graphics mode looks much better on clients that do... we recommend switching to Netscape 3.0 or Microsoft Internet Explorer.
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Rotating Updrafts
visual clues

There are ample signatures of updraft rotation in this hazy, northeastward view of a very intense supercell from 40 miles away. The circular mid-level cloud bands and the smooth, cylindrical Cb strongly hint of updraft rotation. Above the mid-level cloud band, an extremely hard Cb top is barely visible (upper right) towering into the anvil. Note the smooth, "laminar" flanking line on the extreme left. A strong, "capping" temperature inversion in the low levels probably accounted for the laminar appearance of the flank.

[Image: supercell with signs of updraft rotation (76K)]
Photograph by: Doswell

Cloud elements moved along the flank into the main Cb, with rapid vertical development occurring at the merger point. Close examination of the photo will reveal a wall cloud beneath the lower left edge of the Cb, with a relatively bright "clear slot" ahead of the wall cloud. Within 20 minutes, the storm produced two significant tornadoes near Alfalfa, Oklahoma.

[Image: westward view of supercell updraft and wall cloud (59K)]
Photograph by: NSSL

A close, westward view of a supercell updraft and adjacent precipitation cascade strikingly resembles the model we have just seen. Wall clouds frequently slope downward towards the precipitation area, as shown. If you are a mobile spotter and encounter a view such as this, turn around and out-run the storm by going eastward or, better yet, move away from the storm to the southeast. This is very close to the fall area of large hailstones, and moving north or waiting at this location will put you in danger from large hail and tornadic winds.



overshooting tops
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.

backlighting