Thundersnow is a thing; we explain what it is.

IDAHO FALLS — East Idaho residents woke to a rare weather phenomenon on Saturday morning: thundersnow.

Thundersnow is precisely what the name suggests — a regular thunderstorm, but with snow instead of rain. But the winter version of a thunderstorm is relatively rare, according to the National Oceanic and Atmosphere Administration.

Where there is thunder, there is lightning. Lightning associated with thundersnow storms is less frequent than in summertime storms, says the NOAA. Instead of strikes that travel to the ground, it is usually the cloud-to-cloud variety.

Thundersnow happens when there’s a lot of moisture and instability in the air above the ground, like above a warm front. The key factors are moisture, instability and rising warm air. These ingredients are plentiful in the spring and summer but less so during winter snow storms.

Eastern Idaho experiences thundersnow a couple of times a year, according to the National Weather Service in Pocatello.