photo #4296657

As Cumulus congestus clouds grow in height, they can lift up moist, stable airstreams overhead. The air is cooled as it is lifted, sometimes enough for the moisture it carries to condense into an accessory cloud known as a pileus, Latin for a ‘cap’. When building clouds don their hats like this, they’re telling anyone below to do the same before the showers start.Cumulus congestus with pileus, spotted near Venice, Florida, US by Dan Piorier (Member 58,837).