photo #4946594

Based on the images of cloud formations in reference books, you’d be forgiven for assuming the pouch-like cloud features known as mamma appear only, like the ones on the left here, attached to large Cumulonimbus storm clouds. While it is true that the majority of sightings of mamma are when the cloud features are associated with storms, this is just because the lobes look most dramatic when they’ve formed on a huge Cumulonimbus. In fact, the features can develop on several of the ten main cloud types.Mamma can appear wherever the air within a cloud cools rapidly and starts to sink in pockets that shape the cloud’s underside. They form at different levels in the atmosphere, from those of low Stratocumulus clouds to high Cirrus and in between. On the right here, subtle mamma features have developed in a region of the high ice-crystal cloud Cirrus, giving it an uncharacteristically bumpy appearance. Take your cloudspotting skills to the next level, and try to find mamma not just in dramatic stormy skies, where they scream for everyone’s attention, but also tucked away in the cloudy margins, where they gather in patches on some of the other main cloud types, and where they rarely make a fuss.Left: Cumulonimbus with mamma spotted over Mannheim, Germany by Julia Vogelsgesang (Member 41,128). Right: Cirrus with mamma spotted over Haywards Heath, West Sussex, England by Elliot Chandler (Cloud Appreciation Society Member 16,353).