Thundersnow in Central Indiana? What to know about the rare occurrence

About 8:10 a.m. Wednesday, as the snowfall in Central Indiana began picking up, the National Weather Service confirmed Johnson and Brown counties has experienced thundersnow.

Did anyone happen to hear this?

While many are familiar with the weather phenomenon, some people were left wondering, “what the heck?”

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What is thundersnow?

“Essentially what is happening is just like with a thunderstorm. During winter events we can get lightning with snow,” said National Weather Service meteorologist Andrew White, stationed at the Indianapolis office. “It's just a much, much less common occurrence. It's a lot more difficult to get lightning during snow compared to a heavy rain event."

Is there always lightning with thundersnow?

“Thunder is a direct consequence of lightning, and it can only happen if lightning occurs,” said Joseph Nield, also a meteorologist at the local office. “The thunder is the sound created by the rapid expansion of air due to the heat from the lightning.”

Is the threat of lightning any bigger in winter storms than in summer thunderstorms?

"The amount of danger is the same as it would be during a summer thunderstorm. The only difference is it's not going to be as frequent or as widespread. But being struck by lightning out here in the snow would be the same as it would be during a summer thunderstorm,” White said.

How rare is thundersnow?

“It is an unusual event. It’s maybe something we see once a year or so across the area. It's one of those events that when it happens a lot of people take note because it is kind of a more unusual occurrence,” White said. “And it's just not something you think about when it's snowing outside; that there could be some thunder with it.”

How does the lightning and thunder differ in winter storms from rainstorms?

“It’s more difficult to create lightning in the wintertime because typically you’re relying on rapid upward motion that we more tend to associate with summertime thunderstorms as opposed to winter storms,” Nield said. “But  it can happen if the overall force is strong enough to create those rapid motions.”

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Can we expect more today?

“There’s definitely the potential for more of this as we go into the mid-morning hours as the snow banding continues to tighten and get heavier in spots,” White said. “We just want to remind people that the most dangerous time for travel is going to be through the morning hours. So, we want to help people avoid it if possible. And if they do, they want to make sure they give themselves enough playing space and play at time while on the roads.”

Contact IndyStar reporter Cheryl V. Jackson at cheryl.jackson@indystar.com or 317-444-6264. Follow her on Twitter:@cherylvjackson.

This article originally appeared on Indianapolis Star: What is thundersnow? Here's why it happens and where it happened