Nimbostratus

Description of Formation: The dark rain clouds and the ones that form in layers represent Nimbostratus. Its a low, dark blanket or clouds that spread gloom.

Height: Low, below 2,000 meters.

Shape: It is formless, flat and layered and it is often described as a blanket of cloud.

Color: Dark gray.

Weather: Rain or snow.

Source of Photo: http://www.free-background-wallpapers.com/p7ssm_img_1/fullsize/nimbostratus_clouds_fs.jpg