A meteorologist took this picture at dinner. Here's his explanation of the stunning cumulonimbus cloud.

This cool time-lapse clip showcases the amazing way cumulonimbus clouds form, shift, grow, and move across the sky, proving that even "ordinary" fluffy clouds are anything but placid.

Large cumulonimbus clouds filled the sky on Monday night ahead of record-setting heat and the first 100 degree day.

Mother Nature put on a display of convection (rising air) over the mountains, lifting moisture rapidly toward an invisible ceiling in the atmosphere.The event ...