Nimbostratus is the first mid-level cloud in our series, but you can evaluate it like a low-level cloud! Why? Let us find out!

Nimbostratus is the second highest cloud. The highest (vertically most developed) is Cumulonimbus, that appeared in our previous article. Nimbostratus can reach 4 km (13 000 ft) in high and thousands of kilometres horizontally. Its base is below 3 km (10 000 ft) from the ground, and sometimes it can be created below 2 km (6 500 ft), which would make it a low-level cloud. But how does one look like?

It is basically a thick grey or even darker layer. For its thickness, you cannot see Sun through it, which is the most notable difference between Nimbostratus and Stratus. Also, Nimbostratus is not so uniform and mainly causes persistent precipitation that cannot be associated with Stratus. But the precipitation can be caught in a layer above the ground and the rain can vaporize just before falling down on us.

Nimbostratus occurs along a warm or occluded front, where warm air rises and the cloud is created just like cumulus, but in a way larger area. It can also appear from the transformation of Altostratus, Altocumulus or Cumulus.

Nimbostratus can sometimes hide Cumulonimbus inside and therefore it can be associated with storms. There are special meteorological warnings for flights about the chances of thunderstorms in Nimbostratus and only meteorological radars can detect it for its detailed scan of the structure of clouds.

Nimbostratus has no species and even no varietes.

Have you seen this big boy? Send your photos!