Weather Wonders: wall clouds vs shelf clouds

Weather Wonders: wall clouds vs shelf clouds

This week's Weather Wonders is all about clouds - specifically, how to tell the difference between a wall cloud and a shelf cloud.

This photo of a shelf cloud was sent in to us from Jessica McCloy, of New Boston. A shelf cloud forms as rain-cooled air from a downdraft sinks and spreads out across the earth's surface. Ahead of this cooler air, is rising warm moist air. The rising air tilts above the cooler air, feeding the storm. The warm moist air condenses and forms the shelf cloud appearance. They often form at the leading edge of a gust front, which is why you may feel a strong cool blast of air as this cloud passes overhead.

Shelf clouds slant downward away from the precipitation that follows it.

Fabiola Marth Hdz of Keithville sent this photo of a wall cloud to us. A wall cloud is a cloud that is lowered from a thunderstorm. It forms when rapidly rising air causes lower pressure below the storm's main updraft. If this cloud begins to rotate, that could be an indication that a tornado may form. Shelf clouds could stretch for miles, whereas wall clouds are typically smaller in length.

Wall clouds generally slope upward away from the area of precipitation.

If you have any of your own Weather Wonders send them my way!


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