Whirlwinds!
It is late afternoon in the summer. The air is hot and sticky. In the
distance, a long line of clouds is gathering. There is a rumble of
thunder.
The line of dark clouds comes swirling over the prairie. Small, shaggy
lumps of cloud hang from the bottoms of some of the larger clouds. A
crackling rain of hail comes pouring down, and the sky flickers with
lightning.
Suddenly, from the lumpy mass at the bottom of a cloud, a dark cone
sweeps down toward the earth. It looks like a huge, twisting snake
hanging from the cloud. There is a terrible roaring noise!
It’s a tornado!
Tornadoes are sometimes called whirlwinds or twisters. A tornado is a
spinning, whirling wind that forms a long tube of air. Where the tube
touches the ground, terrible things happen! The whirling wind can pick
up a heavy truck and throw it through the air. It can pull houses apart
and knock big, thick trees over.
Tornadoes are caused when there is warm, moist air beneath cold, dry
air. The warm air rises up and cools quickly, letting go of its heat and
water. This makes hail and rain fall. Air comes rushing in from all
sides to take the place of the rising warm air. Because the wind blows
from several different directions, the air begins to whirl.
Tornadoes can happen in many parts of the world. But most tornadoes
happen over the central part of the United States.
