In which situation is advection fog most likely to form?

Advection fog forms when warm, moist air moves over a cooler surface, causing the air to cool to its dew point and form fog. In this context, the situation where an air mass moves inland from the coast in winter is particularly conducive to advection fog. When this warm, humid air encounters cooler land temperatures, especially if the land has relatively low thermal inertia like coastal areas in winter, it cools rapidly, leading to condensation and the formation of fog.

The distinction is important; in winter, coastal air is often warm and moist, while the land inland cools, providing the necessary conditions for this type of fog. Other conditions, such as the geography or temperature differentials, can significantly enhance the likelihood of advection fog formation, making this scenario a classic example of the phenomenon.