Violent weather can occur anywhere. Depending on where an outbreak occurs, there will be different types of storms. However, not all storms are violent. There are, for example, thunderstorms that are not severe, and tornadoes that do not cause extensive damage. Common measurement scales do not provide an understanding of the strength of a weather disturbance. Consequently, meteorologists must use different scales to measure the strength of weather systems, and to make predictions about when violent weather may strike.

Thunderstorms

There are three ingredients necessary for a thunderstorm to form:

1. moisture must be present in the lower levels of the atmosphere;
2. cold air must be present in the upper atmosphere; and
3. there must be a catalyst to push the warm air into the cold air.

This catalyst is usually in the form of a front, which is the interface between air masses at different temperatures. As...