Here in the Midwest, the sound of thunder in the distance is a familiar one. We are used to hearing the claps and booms as thunderstorms approach, but have you ever heard a clap of thunder during a snowstorm?

Thundersnow is not nearly as common as the thunder we experience during rainstorms, but it does happen from time to time when the right combination of conditions come together. The conditions needed for thundersnow are the same factors required for a summer storm to develop: instability, moisture and a lifting mechanism in the atmosphere. However, thundersnow requires relatively strong instability and an abundant supply of moisture over a warm front, according to the National Oceanic Atmospheric Administration.

Thunder is not common during snowstorms because normally when it snows the air is the same temperature at the high and low levels of the atmosphere, the NOAA reports. On rare occasions, however, shallow layers of warm air can lift into the atmosphere during a snowstorm. This can cause an electrical charge in the atmosphere, leading to lightning and thundersnow. Yes, just like during a traditional thunderstorm, thundersnow is accompanied by lightning. In fact, thunder is always accompanied by lightning because thunder is the sound lightning makes.

Thundersnow occurs during heavy snowfall because those same shallow layers of warm air that cause the lightning and thunder also increase snowfall rates. Meteorologists often track incidents of lightning — and therefore thundersnow — during winter storms because it is an indication of heavy snowfall and rapid accumulation, which can cause hazardous conditions.

Thundersnow is a relatively rare phenomenon for a few reasons. First, thunder during a snowstorm is quieter than during a typical thunderstorm because of the sound-dampening effect of snow. While thunder from a summer thunderstorm might be heard from many miles away, you typically have to be within 2 miles or 3 miles of thundersnow to hear it, the United Kingdom Met Office reports. That means even when thundersnow does occur, fewer people hear it than they would hear thunder from a spring or summer storm.

And because of the precise conditions needed for thundersnow to occur, you have to be lucky to experience it for yourself. It’s most common during periods of intense, heavy snowfall, and it also most commonly occurs when the air temperature is around or even a little above freezing, according to the University of Illinois Extension.

Both the heavy snowfall and temperatures hovering around freezing level are indicators of instability in the atmosphere. During these periods of instability, pockets of air are sent upward, higher into the atmosphere. As they ascend, an electrical charge can build and build until it is discharged in the form of a bolt of lightning and clap of thunder.

Thundersnow most commonly occurs in areas that experience lake-effect snow, including the Great Lakes region and the area around Great Salt Lake in Utah. This is because the conditions necessary for thundersnow occur more frequently around these large bodies of water, where differences in air and water temperature can create the instability that sets the process into motion.