What weather conditions can be expected beneath a low-level temperature inversion layer with high humidity?

The presence of a low-level temperature inversion layer typically results in distinct atmospheric conditions. In this scenario, the cool air trapped below the inversion layer can lead to a buildup of moisture. When high humidity is present, the air beneath this layer can become saturated, resulting in poor visibility due to fog, haze, or low clouds.

As warm air overlays cooler air at the surface, any upward movement is restricted, which can further contribute to the development of these conditions without significant turbulence. The inversion stabilizes the air and inhibits mixing, leading to the smooth air often associated with such layers. Therefore, the expected weather conditions beneath a low-level temperature inversion with high humidity include a combination of smooth air, poor visibility, fog, haze, or low clouds, making this the correct answer.