Forecasters warn an extreme winter storm could trigger rare “exploding trees” across the Upper Midwest as temperatures plunge ...

Experts say it’s extremely rare, but not completely unheard of.

As more than half of the United States braces for a powerful winter storm, some meteorologists are warning on social media that “exploding trees” are possible.

While the Wisconsin DNR says ‘exploding’ may be an exaggeration, there is a risk for frost cracking. That happens when the sap inside a tree gets below freezing, and expands.