Thundersnow is a particularly rare meteorological phenomenon that includes the typical behavior of a thunderstorm but with snow falling as the primary precipitation instead of rain.

There are usually two forms of thundersnow:

• A normal thunderstorm on the leading edge of a cold-front that passes over a colder body of water (with subsequently colder air around it) which in turn changes the precipitation to snow.
• A heavy snowstorm that catches a warm draft of air which allows favorable conditions for lightning and thunder to occur.

One unique aspect of thundersnow is that the snowfall acts as an acoustic suppresor of the thunder. The thunder from a typical thunderstorm can be heard many miles away, while the thunder from thundersnow can usually only be heard within a 1-2 mile radius from the lightning.

Thundersnow, while rare anywhere, is more common to the Great Lakes area of the United States and Canada, the midwestern U.S., the Great Salt Lake, and has also been reported around the Sea of Japan and even around Mt. Everest during expeditions.

External Links

• What causes thundersnow?
• A study of opposites: Thundersnow
• Straight Dope Staff Report: Why don't snowstorms produce lightning?