Mammatus clouds over Cleveland Mammatus are pouch-like cloud structures. They're also a rare example of clouds in sinking air-- most clouds form in rising air. Although mammatus most frequently form on the underside of a cumulonimbus, they can develop underneath cirrocumulus, altostratus, altocumulus and stratocumulus. For a mammatus to form, the sinking air must be cooler than the air around it and have high liquid water or ice content. They derive their name from their appearance, like the bag-like sacs that hang beneath the cloud resemble cow's udders. Mammatus are long-lived if the sinking air contains large drops and snow crystals since larger particles require greater amounts of energy for evaporation to occur. Over time, the cloud droplets do eventually evaporate and the mammatus dissolve.
Another shot from last Saturday evening. I raced down to Raby bay thinking that I would get some storm shots instead I was greeted by this amazing sunset. is it any wonder that I love doing this.
The sky lit up beautifully as a storm passed to the north at sunset