Continuing with our review of the cloud genera cataloged by the WMO, we remember that last time we talked about the Altostratus, today we talk about the third type of middle clouds, we refer to the Nimbostratus or Nimbostratus.
They are described as a gray cloud cover, often dark, with a veiled appearance by the precipitation of rain or snow that falls more or less continuously from it. The thickness of the cloud is great enough to hide the Sun completely. They are made up of water droplets, supercooled raindrops, raindrops, crystals, and snowflakes.
The Nimbostratus usually forms when a huge and extensive layer of relatively warm and humid air rises
above a cold mass, on a progressive and gentle slope. It is, together with the Altostratus, the main nucleus of
un warm forehead. It is a very difficult cloud to distinguish, as it appears as a uniform dark gray veil,
without any discontinuity and occupying the entire sky, mixed with precipitation. Likewise, it occupies a
great vertical dimension, in the thickest sites it can cover between 1 - 5 km, occupying, in part,
the floor under the clouds. They usually give continuous rain or snowfall, mainly associated with warm fronts.
They are very difficult to photograph. The lack of light, together with the precipitation that falls from its interior, makes the sky
look like a huge dark gray canvas without any detail. It is advisable to try to photograph them when low torn clouds are passing under them, that is, stratus fractus. It is important not to confuse them with the Altostratus, the Nimbostratus do not allow us to see the Sun in any way and they almost always produce moderate rainfall. Nor should they be confused with the Stratocumulus as they are less uniform.
These clouds do not have any type of species or varieties.
Source - AEMET
More information - The Altostratus
so strange clouds that you already like them