What is ‘thundersnow’ and why would lightning occur within snowstorms?

Sometimes lightning can occur within snowstorms and is called thundersnow.

Thundersnow can be found where there is relatively strong instability and abundant moisture above the surface, such as above a warm front. The ingredients that create thundersnow are similar to the dynamics of a typical thunderstorm -- moisture, instability, and a lifting mechanism.

Thundersnow is sometimes observed downstream of the Great Salt Lake and the Great Lakes during lake-effect snowstorms, too, according to the NOAA National Severe Storms Laboratory.

Here’s more from NOAA:

Here’s the simple science: air is considered unstable if it continues to rise on its own after getting a nudge from a cold front or warm front. This rarely occurs when it’s snowing because the air temperature in winter snowstorms is consistently cold, at both high and lower points in the atmosphere.

However, in some winter storms, shallow layers of warm air are lifted and continue to rise on their own - increasing snowfall and causing enough electric charge separation for lightning to occur.

So if you hear a rumble of thunder during the storm -- no, you’re not hallucinating! It’s real.

---> MIPics: Share your Michigan winter storm photos