Altocumulus clouds with dark stratus cloud beneath near sunset

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Altocumulus clouds form between 6500 feet (2000 meters) and 20,000 feet (6000 meters). When mid-altitude altocumulus or high-altitude cirrocumulus display an undulating or rippled appearance, the so-called 'mackerel sky,' they often signal a change in weather.

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Size: 5200px × 3467px
Location: Northern California, CA, United States
Photo credit: © Denise Dethlefsen / Alamy / Afripics
License: Licensed
Model Released: No

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