The rare formation is known as "morning glory clouds," CNN meteorologist Brandon Miller explained.
"The low, horizontal clouds form as a wave travels through the atmosphere and encounters layers of air with different temperatures and humidity levels," he said. "If these layers are at just the right combination of temperature and humidity, they can form clouds as the air rises at the waves' crests -- and no clouds in between, where the air is sinking.
"This explains why the clouds look like "breaking waves approaching a shoreline," Miller said.
We also like this shot of Milford Sound in New Zealand with menacing clouds threatening to bring rain.