The drama of last week’s pre-winter snowstorm was heightened by the booming sound of thunder-snow. This is the term used to describe thunder and lighting that takes place during a large winter storm, a rare meteorological event.

Thunder-snow, like any thunderstorm, is the result of convective processes. What makes it rare, is the fact that it requires very precise conditions that are unusual in winter. For example, the air near the ground needs to be warmer than the air above it, yet still cool enough to support snow. The main difference between thunder-snow and a regular thunderstorm is the form of precipitation that reaches the ground…snow instead of rain.

Growing up in the northeast, I never experienced thunder-snow until last winter here in New York City. During that busy winter season, we heard it’s startling sound a few times. Last week’s pre-season snowstorm unleashed it again. For a rare phenomenon, it seems to be happening more often. I wonder if there is a reason for this increased frequency?