Glossary
Aviation Weather
Visibility (VIS)
Definition
The greatest distance at which prominent objects can be identified with the unaided eye
Related Terms
Ceiling
The height of the lowest layer of clouds covering more than half the sky
Decision Height (DH)
The altitude during a precision approach at which the pilot must decide to land or go around
Fog
Visibility-reducing water droplets suspended near the surface, a major cause of airport delays
METAR (METAR)
Aviation Routine Weather Report — a standardized format for reporting current weather conditions
Statute Mile (SM)
A unit of distance equal to 5,280 feet or approximately 1.609 km