Severe weather (thunderstorms, tornadoes, and floods) can happen year round here in the Deep South.
Terms to know:
Tornado: A violently rotating column of air in contact with the ground. Winds inside a tornado could exceed 250 miles per hour, making it capable of causing extensive damage. They may last from just a few seconds or minutes to well over an hour.
Severe Thunderstorm: A thunderstorm that has winds of 58 miles per hour or greater and/or hail 3/4 an inch in diameter (about the size of a penny). They are also capable of producing numerous lightning strikes and heavy rainfall capable of flash flooding.
Flash Flood: A flood which is caused by heavy or excessive rainfall in a short period of time, generally less than 6 hours. Also, at times a dam failure can cause a flash flood, depending on the type of dam and time period during which the break occurs.