WW2010
University of Illinois

WW2010
 
welcome
 
online guides
 
archives
 
educational cd-rom
 
current weather
 
about ww2010
 
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

.
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