Altitude MSL of base of thunderstorm layer. Returns 0 if no thunderstorm layer is active. Measured in feet. 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
IF CLOUD_THUNDER_BASE < 5000 AND CLOUD_THUNDER_TOP > 35000 THEN
PRINT "Stay well clear of those thunderstorms."
ENDIF