A type of dark grey layered cloud that brings almost continous rain or snow. It is formed at an altitude of approximately 19,000 feet.
A dark, gray cloud characterized by more or less continuously falling precipitation. It is not accompanied by lightning, thunder, or hail.
A principal cloud type, gray in color and often dark, appearing as a solid sheet. Nimbostratus produce more or less continuous rain or snow or other type of precipitation, not accompanied by thunder and lightning.