ALTOONA, Pa (WTAJ)- Did you get to see the Pileus clouds over Central Pa? They are the soft umbrella shape clouds that form on top of cumulus and cumulonimbus clouds.
What causes this type of cloud to form? Pileus clouds form when warm moist air rises very quickly and condenses on top and around the top of cumulus and cumulonimbus clouds. The quick speed of the updraft and water condensing forms the smooth umbrella or cape shape. These clouds are often called scarf clouds or cap clouds and are short-lived.