Montserrat and Massive Mammatus Clouds

Mammatus Clouds Over Montserrat, Catalunya, July 31, 2021

“For photography, I am not a fan of clear blue skies.”

–Said by me.

Why not?

Simple. Clear blue skies lack interest.

Maybe that’s why I prefer to do my photography during the fall, winter, and early spring months. Usually, the weather is more unsettled and can even be quite exciting, meaning more attractive images.

Today, though, was one of those odd summer days when the sky was actually worth gaping at and worth photographing.

Unfortunately, I was not in a position to place an appropriately intriguing foreground in the same rectangle along with the spectacular “mammatus sky”. So… I just used my iPhone to record the heavenly spectacle. I did, however, manage to catch an airliner passing underneath the extraterrestrial curtain, so I was very happy with that–it gives things some scale and adds a nice focal point, making an interesting image a bit more interesting. Ah, serendipity!

So, what is this other-worldly phenomenon? 

They are: “Mammatus Clouds”

Here is what Ms. Wikipedia has to say (to save you the effort of a click):

“Mammatus (also called mamma or mammatocumulus, meaning “mammary cloud”) is a cellular pattern of pouches hanging underneath the base of a cloud, typically a cumulonimbus raincloud, although they may be attached to other classes of parent clouds. The name mammatus is derived from the Latin mamma (meaning “udder” or “breast”).

According to the WMO International Cloud Atlas, mamma is a cloud supplementary feature rather than a genus, species or variety of cloud. The distinct “lumpy” undersides are formed by cold air sinking down to form the pockets contrary to the puffs of clouds rising through the convection of warm air. These formations were first described in 1894 by William Clement Ley…

True to their ominous appearance, mammatus clouds are often harbingers of a coming storm or other extreme weather system. Typically composed primarily of ice, they can extend for hundreds of miles in each direction and individual formations can remain visibly static for ten to fifteen minutes at a time. While they may appear foreboding they are merely the messengers – appearing around, before or even after severe weather.”

[Note: In today’s case, there was no immediate bad weather once the mammatus clouds disappeared–but we did have a massive thunder/rain/lightning storm in Barcelona that evening.]

For a better view of the airliner (likely leaving Barcelona’s El Prat Airport), here is a close-in crop of the above image. They say that severe turbulence can accompany this type of cloud formation, so I imagine the tray tables were stowed and the Captain had the seat belt sign illuminated–and she probably avoided climbing through that cloud deck. What did it look like from her viewpoint in the left seat, I wonder?

Mammatus Clouds Over Montserrat, Catalunya, July 31, 2021 (Cropped.)