Cloud-watchers can talk all about the interesting shapes they've noticed over the years. They may have been gazing out the car window during a road trip, or tanning on the beach, or on a morning walk.

A “roll cloud” spotted off the coast of Portugal looked like something out of a movie. Here’s the science behind it.

Owen told me that the picture was simply of a sunset over Hawaiian ocean waters. Yep, that's it. It is not even volcanic activity as some have also reported.

The impact of the recent Saharan dust cloud was likely most severe in the Caribbean. Ordinarily, the concentration of PM10 is 10 to 20 micrograms per cubic meter of air, mostly due to sea salt.

The clouds are called Kelvin-Helmholtz clouds and are unusual to see in Florida. ... The faster wind above actually pushes over the tops of the clouds and creates the ocean wave-like appearance.

Coloradans across the Denver metro area were treated to some incredible views of clouds during Monday and night's sunset. Even more viewers saw a similar-looking cloud Tuesday night in the metro ...