These are Mammatus Clouds, and they are a meteorological
phenomenon caused by sagging cellular accumulations produced in clouds of ice and water. When you see clouds like these,
it means a storm is trying to develop.
Tending to form in warmer months over the Midwest and eastern areas of the USA, Mammatus are nonetheless found
elsewhere, as our chase across the States to track this singular meteorological phenomenon will reveal.
The above photograph was taken in Colorado, where citizens are being warned that a storm is brewing. Nature can be
frightening and passionate!