Aeronautical Terms beginning with G

Glaze

A coating of ice, generally clear and smooth, formed by freezing of super.cooled water on a surface.

Gradient

In meteorology, a horizontal decrease in value per unit distance of a parameter in the direction of maximum decrease; most commonly used with pressure, temperature, and moisture.

Ground clutter

Pertaining to radar, a cluster of echoes, generally at short range, reflected from ground targets.

Ground fog

In the United States, a fog that conceals less than 0.6 of the sky and is not contiguous with the base of clouds.

Ground visibility

Prevailing horizontal visibility near the earth’s surface as reported by the United States National Weather Service or an accredited observer.

Gust

A sudden brief increase in wind; according to U.S. weather observing practice, gusts are reported when the variation in wind speed between peaks and lulls is at least 10 knots.