A middle altitude cloud. Characterized by a generally uniform gray to bluish-gray sheet or layer, lighter in color than nimbostratus and darker than high cirrostratus.
large dark, rounded masses, usually in groups, lines, or waves.
The term stratus is used to describe flat, hazy, featureless clouds of low altitude varying in color from dark gray to nearly white.
Noticeable vertical development and clearly defined edges. Cumulo- means "heap" or "pile"
Fog is a collection of liquid water droplets or ice crystals suspended in the air at or near the Earth's surface. Fog is distinguished from mist only by its density, as expressed in the resulting decrease invisibility: Fog reduces visibility to less than 1 km (5/8 statute mile), whereas mist reduces visibility to no less than 1 km. Fog forms when the difference between temperature and dew point is generally less than 2.5 °C or 4 °F.