Turbulence factor of the surface winds layer. Returns 0 (no turbulence) to 255 (most turbulent). Integer. Read-only.
Note: All weather variables report the weather in the aircraft's current location. This weather information only reflects the weather defined by the weather commands if the aircraft is in the area defined by the Weather and Weather_Char commands.
Example
DECLARE WIND_STU
WIND_STU = WIND_SURF_TURB