Fall 'hole punch clouds' seen across the Bay Area

SAN FRANCISCO (KGO) -- Did you see it? There were several across our Bay Area sky Friday morning. It looked like somebody punched holes in the cloud deck.

PHOTOS: Is it a UFO? Hole punch clouds seen around the Bay Area

This cloud formation is called a fallstreak hole. We also call it a hole punch cloud.
Something, like a plane, travels through the cloud layer and disrupts the pressure and humidity within that layer. This causes the super-cooled water and ice crystals to evaporate and sublimate as they fall from the cloudy layer. This creates the brush-like streaks you see below it.

As the moisture falls it leaves dry air behind which produces the hole, and in some cases, an elliptical opening in the cloud deck.

Share your photos and videos of the rare cloud formations on Twitter, Instagram, or Facebook by tagging them #abc7now and we may show them online or on TV.
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