Thunderstorms, CB / TCU
Turbulence, hail, snow, lightning, sustained up- and downdrafts, icing conditions – are all present in thunderstorms. Up- and downdrafts extend far beyond the visible storm cloud. Severe turbulence can be expected up to some distance from large thunderstorms.
Source: ICAO
See also:
Downdraft and Microburst (MB)
Mountain Waves (MTW)
Thunderstorms, CB / TCU
Turbulence Grade Classification
Clear Air Turbulence (CAT) Encounter
Wind Shear