Tornado Journal Entry

Deadly Tornado Rips Oklahoma (February 12, 2009)

A rare winter tornado ripped across southern Oklahoma this week. The deadly twister struck at around 7:30 P.M., leveling much of the town of Lone Grove about 100 miles (160 km) south of Oklahoma City. Eight people were killed, some by flying debris. The tornado destroyed mobile homes, uprooted trees, and tossed cars around like toys.

Twisters usually don't form in the winter because they need a big supply of warm, moist air near the ground. Oklahoma has been hit with 44 February twisters since 1950. The most recent one was in 2000, when a tornado damaged a barn and power lines in the western part of the state.

Tornadoes often result from collisions of two huge air masses. In the United States, cold, dry air from Canada or the Rockies slams into warm, humid air rising from the Gulf of Mexico. The collision can create a funnel cloud of violent winds surrounding an area of extremely low barometric pressure. The cloud becomes a tornado when it touches the ground.

The United States gets struck with more tornadoes than anywhere else on the planet. Most occur in the spring and summer months. They are most common in the central and southern parts of the country. About 800 tornadoes touch down in the U.S. every year, killing an average of 80 people and injuring 1,500 others. The most violent twisters have wind speeds of over 250 mph (400 km/h).