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What can you guys tell me about Mammatus Clouds, what conditions cause their formation, have we ever seen any in the SLC area?
Thanks and be well,
Vern G.
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Great Question Vern, and no mammatus clouds contrary to belief are not rare and if you look for them, they are outside a lot of the time during the summer monsoon season.
Mammatus clouds (personally are my favorite) are given this name, derived from "mamma or mammary" or the cows udder and how it hangs down. They look like hanging down pouches on the underside of a cloud. They generally form on the underside of a thunderstorm anvil but can also occur as a supplement to some other clouds.
The mammatus clouds or the "mamma" which it can be referred to as in some dictionaries is very special. It forms from sinking air, while most regular clouds form from rising air. The sinking air is usually a sign of a weakening thunderstorm. The thunderstorm anvil contains ice crystals, this spreads out at the top of the storm and as it begins to fall it cools the air below it.
A lot of people are put off by these clouds, thinking that it's an indication of a tornado or other wild weather. But it's usually an indication that the severe weather has passed. However, that same thunderstorm can have nasty weather with it closer to the base of the storm. Winds aloft work to spread out the anvil, that's where you see the mammatus forming.
So, no, mammatus clouds aren't rare, but if you live in an area that recieves very few thunderstorms a year, you might not see them as often, especially if you aren't paying attention. Not all of them are as vivid as some of those photos you see and here's some on the links on the right. Mammatus clouds in the midwest happen on a regular basis along with the enormous thunderstorms that appear there. We also have them here in Utah, be sure to be on the look out during the late summer months, but be safe of course and don't go out during a thunderstorm! You can see them when the storm has passed or a decaying thunderstorm is in another place far away from you. They might not look as amazing as some of the ones in the midwest at times, but they are still pretty neat.
Answered by KSL Meteorologist Dina Freedman.
