Let's review the destructive and deadly thunderstorm elements before introducing the thunderstorm spectrum. By definition, all thunderstorms contain lightning. This photograph shows lightning coming from the side of a cumulonimbus cloud.

Photograph by: Moller

In most years it is the thunderstorm's greatest killer. A possible contributing reason for this is that lightning victims frequently are struck before or just after the occurrence of precipitation at their location. Many people apparently feel safe from lightning when not experiencing rain.