These are rotor clouds, and are manifestations of "Lee Waves", a particular kind of internal "gravity wave" (better defined as "buoyancy effect").

Convection has nothing to do with their formation as warm, moist air is literally forced upward by both wind from behind and the mountain barrier in front. The upward movement forces cooling and condensation of vapor into clouds. Once past the mountain barrier, this instability dissipates it's momentum through a series of less intense waves as a function of distance away from the mountain range. The clouds themselves are "standing": they do not move, but are constantly regenerated by the windward moist air mass; nor do they build increasingly larger as they are dissipated on their lee side.

These are rotor clouds, and are manifestations of "Lee Waves", a particular kind of internal "gravity wave" (better defined as "buoyancy effect").

Forced convection helps form these clouds as warm, moist air is forced upward by both wind from behind and the mountain barrier in front. The upward movement forces cooling and condensation of vapor into clouds. Once past the mountain barrier, this instability dissipates it's momentum through a series of less intense waves as a function of distance away from the mountain range. The clouds themselves are "standing": they do not move, but are constantly regenerated by the windward moist air mass; nor do they build increasingly larger as they are dissipated on their lee side.