WW2010
University of Illinois

WW2010
 
welcome
 
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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

Tstorm Components
 
introduction
 
updrafts/downdrafts
 
wind shear
 
outflow phenomena
 
wall clouds

Outflow Phenomena
 
introduction
 
gust fronts
 
microbursts
 
scud clouds, virga
 
rain foot, dust foot

User Interface
 
graphics
text

.
Rain Foot and Dust Foot
driven by microbursts

We are looking west at the south flank of a severe multicell storm that bordered on becoming a supercell at times. Some rotation and several wall clouds accompanied the bursts of large hail and microbursts with this southwest Texas storm.

[Image: initial spotting of rain foot (55K)]
Photograph by: Moller

A rain foot (below) was developing at this time, with rain-free base in the foreground and a small wall cloud southwest of the rain shaft.

[Image: developing rain foot (56K)]
Photograph by: Moller

Several minutes later the rain foot was beginning to curl up towards the wall cloud. Even from this distance of about 10 miles, strong winds were evident from the motions of the laterally spreading precipitation.

[Image: rain foot curls (51K)]
Photograph by: Moller

This seems to verify that a microburst is occurring, and also that many wall clouds likely result from an injection of rain-cooled air into the severe storm updraft.

[Image: has appearance of a tornado (54K)]
Photograph by: Moller

This is not a tornado, but a microburst with precipitation being pulled into the wall cloud and updraft of the multicell storm.

[Image: dust foot (57K)]
Photograph by: Moller

Similar to the rain foot is a "dust foot," seen here spreading and curling upwards from left to right. An aircraft engaged in low-level operations should not venture into these rain or dust feet! Spotters should check out the area that has been affected (if possible) for any sign of damage. This was a multicell storm that also produced heavy rain and small hail.



scud clouds, virga
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.

Wall Clouds