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APTOPIX Ominous Clouds
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  • APTOPIX Ominous Clouds
APTOPIX Ominous Clouds
Mammatus clouds move over the Fredericksburg Agricultural Fair after a round of thunderstorms passed through the area on Thursday, Aug. 1, 2013. Mammatus are most often associated with severe thunderstorms. (AP Photo/The Free Lance-Star, Peter Cihelka)