As thunderstorms formed in the area tonight, an odd cloud took shape before the rain hit. Sometimes this type of cloud can look like a spaceship, or like a scene out of Independence Day. So what is this ominous cloud?
This is a shelf cloud and it's actually more common than you may realize.
This cloud is found at the leading edge of a thunderstorm and has a large wedge-shaped appearance. It's not going to form with all storms though.
The cloud is a a good visual of the boundary between the updraft (rising air in a storm) and the downdraft (sinking air in a storm). That's what creates the smoothed "shelf" part of the storm.
But how does it form?
Rain-cooled air descends in the storm's downdraft. Once that cool air hits the ground, it spreads out and often races ahead of the thunderstorm. At the same time, warm moist air ahead of the storm is lifted at the edge of cooler air. When that warm moist air rises, it condenses, forming the shelf cloud.
Often times a shelf cloud can mean it's about to get windy. We often have gusty winds just ahead of the heavy rain. It doesn't always mean it's about to get windy, but in many cases it does. After that, then comes the heavy rain.
Check out the photos that were submitted below:
You can always submit your great weather photos on whsv.com and the WHSV weather app. (Only if you can take these photos safely of course)