While tornadoes can occur all year long, tornado season in Texas runs from March through August. During these months, it is not uncommon for several tornadoes to occur at once.
The way tornadoes form is not completely understood, but scientists believe they begin when wind shear causes thunderstorms to rotate. As the winds rotate faster, a funnel cloud is formed, and if this cloud reaches the ground, it is called a tornado.
Tornadoes are classified according to the Fujita scale, developed by Dr. Tetsuya Fujita in 1971. The scale ranges from an F0 tornado, with winds less than 73 miles per hour, to an F5, with winds of 261-318 miles per hour.
If a tornado approaches, take shelter in a basement or a room on the lowest floor of the house — preferably one without windows. Cover yourself with a blanket or mattress, if possible, and remain there until the tornado passes.