upper-level chart[¦əp·ər ¦lev·əl ′chärt]
A synoptic chart of meteorological conditions in the upper air, almost invariably referring to a standard constant-pressure chart. Also known as upper-air chart.
A chart used for forecasting and showing the wind pattern and pressures at 40,000, 35,000, 30,000, 18,000, 10,000, and 5000 ft above mean sea level (200, 250, 300, 500, 700, and 850 hectopascals). Contours are drawn at intervals of 200 ft (60 m) at lower levels and 400 ft (120 m) at levels above 30,000 AMSL (300 hectopascals). Also called an upper-level chart