They may have been gazing out the car window during a road trip, or tanning on the beach ... to see Kelvin-Helmholtz clouds, which look like a pattern of ocean waves in the sky.

Swimmers and beachgoers were advised to remain on alert on Wednesday and, in some places, avoid going into the ocean.

Capture the tranquility of a deserted beach as the sun sets ... this dramatic wallpaper of an ocean storm, capturing the ...