Aeronautical Terms beginning with C

Center Weather Advisory (CWA)

An unscheduled weather advisory issued by NWS meteorologists for use by ATC in alerting pilots to existing or anticipated adverse weather conditions within the next 2 hours. A CWA may modify a SIGMET.

Clear Ice

A glossy, clear, or translucent ice formed by the relatively slow freezing of supercooled water drops. The terms “clear” and “glaze” have been used for essentially the same type of ice accretion, although some reserve “clear” for thinner accretions, which lack horns and conform to the airfoil. If the freezing becomes more rapid, clear ice will turn cloudy as small bubbles of air become trapped in the ice. If the conditions persist, the ice would be classified as mixed.

Cold Front

Any nonoccluded front that moves in such a way that colder air replaces warmer air.

Convection

An atmospheric motion resulting in the transport and mixing of atmospheric properties.

Cumulus Clouds

Clouds in the form of detached domes or towers that are usually well defined. Cumulus clouds develop vertically in the form of rising mounds of which the bulging upper part often resembles a cauliflower; the sunlit parts of these clouds are mostly brilliant white. Their bases may be relatively dark and nearly horizontal.

Current Icing Product (CIP)

A graphical planning product that combines sensor and numerical model data to provide a three-dimensional diagnosis of the probability and severity of icing, plus the potential for the presence of supercooled large drops (SLD). This product is automatically produced with no human modification. More information can be found on the Aviation Weather Center (AWC) Aviation Digital Data Service (ADDS) Web site.