Science / Weather / Nimbostratus: This cloud exhibits a combination of rain or snow, and sometimes the base of the cloud cannot be seen because of the heaviness of precipitation. They are generally associated with fall and winter conditions, but can occur during any season.
Technology / Aviation / Scud: A low, foglike cloud layer. MORE
Science / Weather / Middle Clouds: A term used to signify clouds with bases between 6,000 and 18,000 feet. At the higher altitudes, they may also have some ice crystals, but they are composed mainly of water droplets. Altocumulus, alto MORE