Thundersnow Only Occurs in 7 of Every 100,000 Thunder Storms

Many of the ingredients of this rare weather phenomenon align with normal thunderstorm conditions, except that thundersnow occurs in regions which experience significant snowfall.

Lake effect snowfalling (cold air over warm water) is a common cause of turning a typical thunderstorm into a thundersnow storm.

In these cases — more commonly experienced by people living in northwestern Europe or near the North American Great Lakes region and similar environments — air rises quickly when contacting relatively warm water surface temperatures.

Cold air aloft (near the top of the cumulus cloud), as well as steep lapse rates as the air temperature cools rapidly in its climb, create favorable conditions for a storm with greater destructive potential.

Other than lake effect snow, another standard weather system that causes thundersnow is a trough of warm air aloft (most commonly known by its acronym TROWAL).

This inverted trough extends backward into the cold sector of a main cyclone, causing increased winter storm instability.

Hail and snow falling are the most essential ingredients of this winter storm phenomenon. Without the low temperatures required to create a precipitation change from rain to heavy snow showers, you will have the same electric charge that causes lightning and thunder, but flurries will not accompany it.

You might expect that the National Weather Service records copious thundersnow occurrences between the Mid-Atlantic and the Great Salt Lake region each year. However, out of the roughly 100,000 thunderstorms, there are generally less than seven thundersnow storms that occur during winter months.

That means that if you have experienced thundersnow, you are a member of an extremely small club.