What is Altostratus?
A middle cloud type within the B family in the international cloud classification. These clouds consist of water droplets and sometimes ice crystals. In mid-latitudes, the cloud base varies between 15,000 and 20,000 feet. They can range in color from white to gray and bluish. Altostratus clouds can be fibrous or layered and may occasionally form a thick layer that obscures the sun and moon. The halo phenomenon is not observed with this cloud type. It is a good indicator of precipitation or a precursor to a storm. Virga-type clouds fall into this category. They are often formed by variations in low altostratus. They can cause light rain and snowfall. Subtypes of altostratus include opacus, precipitans, and translucidus.
Schedule a Demo Today
A new era is starting with fundamentally new forecasting with unprecedented precision!
Contact UsGlossary
The upward movement of air caused by a topographic barrier, such as a mountain, which can lead to cloud formation and precipitation.
The formation of ice crystals on surfaces when the temperature drops below freezing, typically overnight, causing potential...
Conduction is the transfer of heat or electricity through a material without the material itself moving. This occurs when...
A type of cloud consisting mostly of small particles such as ice particles.
A cloud that develops from Cirrus, completely or partially covering the sky, creating a halo effect, thin, sheet-like, milky...
Convection is the vertical movement of air caused by temperature differences, where warm air rises and cool air sinks. It...
The formation of fog when warm and moist air passes over a cool or cold surface or, conversely, when cold air passes over...
A line on a weather map connecting points of equal atmospheric pressure, used to identify high and low-pressure systems.
A condition in which the stratification of the atmosphere depends on both air temperature and pressure, and where surfaces...
The decrease in temperature with height in an adiabatically rising air parcel (lapse rate). For dry air, this value is 1...

