June 17, 2011 > NASA's Space Place: When Clouds Attack!
NASA's Space Place: When Clouds Attack!
This has been a terrible year for those who live in "Tornado Alley," the region of the Mid-west most likely to experience these violent storms. April 2011 set the U.S. record for the most tornados in any month.
There's little or no warning. One minute it's just raining or hailing, and the next minute the roof or even the whole house is gone. If you were lucky, your family had a few seconds to dive into your basement-if you have one-and not be seriously injured.
With most weather events, you do have a few days or hours warning. This early warning is thanks partly to hard-working satellites that keep a constant eye on Earth's weather from space.
Predicting tornados is a different story. Where do these violent and unpredictable monsters come from? Why do they destroy some buildings, but not others nearby? And why can't weather forecasters warn people to get out of the way?
Certain conditions make tornados more likely. But no one ever knows when, where, how intense, and how many tornados a thunderstorm will create.
Tornados start in thunderstorms. Inside a huge thundercloud, warm and humid air is rising, while cool air is falling along with rain or hail. This situation creates a spinning air current inside the cloud. One end of this spinning column of air can drop down out of the cloud like a finger reaching toward the ground. If it touches, it becomes a tornado.
The winds inside some tornados are the fastest on Earth. They can reach over 300 miles per hour! As the column spins, it also moves along the ground, leaving piles of splinters where once stood perfectly good buildings and trees.
Although current weather satellites can identify storms likely to produce tornadoes, a new kind of weather satellite, the GOES-R, will do a much better job. It will give people more time to prepare for storms that might produce tornadoes, and it will be much better at predicting their severity.
See what a developing storm looks like from space in several videos on the SciJinks weather website for kids at http://scijinks.gov. Play cool weather games while you're there.
This article was written by Diane K. Fisher and provided by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.
Download this image from http://spaceplace.nasa.gov/news-images/ringgold-tornado.jpg.