YOUR PHOTOS: Shelf clouds spotted throughout the Valley ahead of severe thunderstorms

Scattered showers and storms moved through the Tennessee Valley Saturday afternoon, and a few packed straight-line winds that were strong enough to topple numerous trees and power lines.

In addition, these storms produced clouds that look like the ones in the gallery below.

These are called shelf clouds, and they occur when the leading edge of rain-cooled air shoves warm, humid air higher into the sky. Occasionally, wall clouds (precursors to tornadoes) can be found within a shelf cloud, but for the most part, shelf clouds indicate the possibility of gusty winds as well as very heavy rain.