Which situation is most conducive to the formation of advection fog?

The formation of advection fog is primarily influenced by the movement of air masses and their respective temperatures and moisture levels. In the context of the correct answer, the process involves a warm, moist air mass settling over a cool surface, which results in cooling of the lower layers of the air. When the warm air gains contact with the cooler surface, its temperature drops, causing the moisture in the air to condense into tiny water droplets, thereby forming fog.

This scenario is particularly effective for advection fog because the cool surface efficiently removes heat from the warm, moist air above. The calm conditions often accompanying this setup—where winds are light or nonexistent—further facilitate the condensation process, allowing fog to develop and persist.

In contrast, cold, dry air over a warm surface tends to create different weather phenomena rather than fog, as the temperature contrast can lead to evaporation and potentially to the development of other types of clouds. Similarly, cool air moving over warm water could lead to the formation of steam fog rather than advection fog. When warm air rises quickly over cold terrain, it generally leads to instability and potential convection but is not conducive to the gradual cooling and condensation required for fog formation. Thus, the characteristics of the warm, moist air mass