Average (50%) Meteorology
Average (50%) Meteorology : Meteorological conditions that, for a particular area, correspond to the median amount of mixing of pollutants with the less contaminated surrounding air. The term indicates conditions during which more favorable mixing conditions occur 50% of the time and less favorable mixing conditions occur 50% of the time. The term "average meteorology" is often used without further definition; it corresponds to a median value. See: Conservative (95%) Meteorology