Dear Tom,
Do thunderstorms that grow higher than usual also tend to be more severe?
Ronny Nauta
Dear Ronny,
A general relationship between thunderstorm height and thunderstorm severity does
indeed exist: The higher the cloud top relative to other thunderstorms in the air mass,
the greater is the storm's severity. We measure thunderstorm severity by the strength of
its straight-line winds, the size of its hail and its ability to generate tornadoes.
Thunderstorm top height is the single most telling factor in storm severity, but speed
is also critical. Fast-moving thunderstorms (40 m.p.h. or greater) tend to be more
severe than slower-moving storms. Note that lightning production and heavy rain, even
flood-producing rain, are not defined to be severe criteria even though such aspects of
thunderstorm weather are dangerous and potentially deadly.
