FYI: Snow, Thunder, and Lightning

Why don't snowstorms produce thunder and lightning?

Snowstorms do produce thunder and lightning - only less frequently than summertime thunderstorms. Also, snowflakes - with a larger surface than raindrops - scatter sound and light more efficiently. In addition, visibility during snowstorms is often very low, making the flashes harder to see.

The flashes, or lightning, that you see in the sky are giant atmospheric sparks caused by a sudden release of energy between separated electrical charges in the clouds. Local variations of wind speed and direction - or shear - transport charges to different areas within a cloud, until the potential grows strong enough for a discharge.

In winter, strong localized shears are uncommon and charge separation is weak. Lightning will still occur at the frontal zones, however, where cold air meets warmer air.

In the Great Lakes region, cold air from Canada meets the warmer air over the lakes and causes precipitation. "You'll get thunder snowstorms right along the south shores of Lakes Ontario and Erie," says Rick Watling, a meteorologist with the National Weather Service.

And although lightning is less common in winter, it is even more deadly than at any other time of the year, Watling says. That's because wintertime strikes tend to carry more current then their summertime counterparts.