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In The Photos of the Readers of La Vanguardia we can see these two images from this morning in Barcelona with showy mammas in medium clouds.
The supplementary feature mamma appears often but not exclusively associated with thunderclouds. This is not the case this Monday, as they are medium altostratus clouds, which have barely dropped four drops of mud at the Fabra Observatory, from where the photographs were taken.
Mammatus clouds can persist in the sky from a few minutes to several hours, until they fade and disappear.
These formations were first described in 1894 by William Clement Ley, who was a pioneer clergyman in meteorology who used weather forecasts.
The Fabra is not only an astronomical observatory, but, as we can see in these images, it is also a splendid viewpoint of Barcelona and even Mallorca. It is located on a buttress of the Tibidabo mountain, facing south, at an altitude of 415 metres.
