This document discusses different types of severe weather events including tornados, blizzards, and thunderstorms. It defines a tornado as a rapidly rotating column of air in contact with the ground and cloud, often forming a funnel shape. Tornados are formed when cold air mixes with hot air, causing the air masses to rotate quickly. Blizzards are severe snowstorms with sustained winds over 56 km/hr that last for 3 or more hours. They form when rain mixes with cold air below 0°C and wind. Thunderstorms contain lightning and the sound of thunder, and are characterized by the presence of lightning in the atmosphere.