Gold Canyon / NW Mesa Weather and Arizona Lightning Data
Shelf cloud over Camelback

Posted on Sep-23-2016 at 00:00:00

A storm system moved through the state Thursday (Sept 22), resulting in the development of several strong thunderstorms.

One storm moved directly over Camelback Mountain giving many in the Valley a spectacular view. So what exactly was this cloud formation?

Quite simply, this was a shelf cloud. It forms when there is a clash between two different air masses.

The first air mass is the cold/dense air moving out from underneath the thunderstorm. The cool air is the result of the rain falling in the downdraft portion of the thunderstorm. 

The second air mass is warm/humid air already ahead of the thunderstorm.

When the cold/dense air moves rapidly across the surface out ahead of the thunderstorm, it forces the warm/humid air off the ground. As the air rises it cools slightly and condenses, forming the shelf looking cloud.

Shelf clouds are often associated with very strong winds directly ahead of a strong thunderstorm.

As the shelf cloud moves over a given location, expect strong winds, much cooler temperatures and at times, rain directly following the passage.

Did you snap any photos? Tweet them to me: @mattpaceweather 

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