Just when I thought about putting away my winter coats, the weather turned again. On Tuesday, I was driving home from work when a large mass of storm clouds loomed into view. Within a few minutes, thunder boomed and multiple lightning strikes flashed before me. I was actually enjoying the light show until the heavy downpour of rain came. Even though I had the windshield wipers going full blast, I could barely see the painted lines on the road. I never drove in rain as heavy as this before, and I slowed down along with other drivers on the road in the hope of avoiding an accident. Water swelled and flooded the streets. Suddenly, the storm disappeared as fast as it came, and the sun shone again . . .
Besides giving me a free car wash, Tuesday’s rain inspired me to do a post about storm clouds. This week’s post features storm clouds called shelf clouds. Here is a brief description of them from the Mother Nature Network website:
Shelf clouds are a type of arcus cloud, formed by colliding updrafts and downdrafts. As a storm vacuums up warm air from below, it also pumps out cooler air at the top, which can spill forward, slip below the warm updrafts and condense into a horizontal “shelf” . . . .
Some shelf clouds have a blue glow to them. The Mother Nature Network website describes this as a “’glow discharge,’” which “can occur when a thunderstorm is close to the ground, creating a large ‘surface charge density’ for a long, slow-burning lightning strike — similar to how an electrical charge illuminates suspended particles in a fluorescent light bulb.”
Furthermore, shelf clouds are not always as menacing as they appear to be. They “mainly serve as harbingers of more severe weather on the way — and even then, they’ve been known to exaggerate the threat. ”
Source for all quotes in this post: “9 scary images of shelf clouds” (a photo gallery with text by Russell McLendon) – Mother Nature Network