What occurs when stable air flows over a mountain at slow speeds?

When stable air flows over a mountain at slow speeds, smooth laminar flow typically occurs due to the characteristics of stable air. Stable air is defined by a lack of significant vertical movement, which means that it tends to follow the contour of the underlying terrain without creating substantial turbulence. In this scenario, because the airflow is slow, the air can smoothly ascend and descend along the mountain slopes without the disruptive forces that would create significant turbulence.

Laminar flow refers to a state of flow where the fluid moves in parallel layers, with minimal mixing or disruption between these layers. This is typical for stable conditions where the air is stratified and experiencing minimal friction or disturbances, allowing the airflow to remain smooth as it interacts with the mountain topography.

The nature of stable air implies that any vertical movement induced by the terrain will be gentle, further supporting the presence of laminar flow rather than the chaotic conditions associated with turbulence or downdrafts.