Nimbostratus
What is Nimbostratus?
These clouds are similar to stratus clouds in that they form a gray layer that cover all or a large part of the sky, however, they are thicker and darker than stratus clouds. Nimbostratus clouds may fuse with stratocumulus clouds below or altostratus clouds above, making their upper and lower edges difficult to distinguish.
Nimbostratus often brings continuous, light to heavy precipitation that last more than twelve hours. This precipitation may evaporate and produce a low-lying cloud or fog, further reducing visibility on the ground. Because the base of nimbostratus cloud is formed around 4 km above the ground, this type of cloud is sometimes classified as part of the middle group of clouds.
Nimbostratus often brings continuous, light to heavy precipitation that last more than twelve hours. This precipitation may evaporate and produce a low-lying cloud or fog, further reducing visibility on the ground. Because the base of nimbostratus cloud is formed around 4 km above the ground, this type of cloud is sometimes classified as part of the middle group of clouds.