WW2010
University of Illinois

WW2010
 
  welcome
 
> online guides
 
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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

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

Dangers of T-storms
 
  lightning
 
  flash floods, hail
 
> outflow
 
  downbursts
 
  tornadoes

User Interface
 
  graphics
> text

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Outflow
winds flowing outward from thunderstorms

Thunderstorm winds also cause widespread damage and occasional fatalities. Thunderstorm "straight-line" winds originate from rain-cooled air that descends with accompanying precipitation. This central Texas windstorm, approaching from the west, was packing 80 MPH winds behind the spectacular appearing gust front. The same thunderstorm earlier produced several small tornadoes, grapefruit size hail, and flash flood rainfall. (Looking west from about 5 miles.)

[Image: thunderstorm outflow (70K)]
Photograph by: Moller

After the thunderstorm gust front passes and before precipitation, if any, arrives, blowing dust often is kicked up by thunderstorm induced winds. The amount of dust depends on soil type, soil moisture content, and wind intensity.

[Image: wind sock hidden by blowing dust (43K)]
Photograph by: Moller

Note the aviation "wind sock" in the photograph. Winds were estimated to be about 50 MPH at this time along the Texas-New Mexico border east of Hobbs, New Mexico. Severe thunderstorm winds are especially dangerous to aviation interests, particularly aircraft which are on final approach or taking off.

Many western US storms, such as this one in southern Colorado, have extremely high bases and low tops. Don't let the weak appearance fool you! Some of the "dry storms" can produce dangerous microbursts and copious amounts of fire-setting lightning.

[Image: high-based storm (39K)]
Photograph by: Moller

Recent research has shown that microbursts, both "dry" ones such as this (actually some very light rain may fall with a dry microburst) and "wet" ones frequently are the cause of wind shear induced aircraft accidents.



flash floods, hail
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.

downbursts