Which phenomenon is typically marked by a change in wind direction?

A weather front is typically indicated by a noticeable change in wind direction. This occurs because a front represents a boundary between two different air masses, which can vary in temperature, humidity, and pressure. As these air masses interact, they cause shifts in wind patterns. When a cold front moves into an area, for instance, wind may shift from a southerly direction to a northwesterly direction as the colder air displaces the warm air ahead of the front.

In contrast, storm surges, fog formation, and cloud development do not inherently involve a change in wind direction. Storm surges are primarily related to changes in atmospheric pressure and wind speed associated with storms, but they do not specifically denote a shift in wind direction in the way that fronts do. Fog formation is usually a result of humidity levels and temperature, rather than changes in wind. Similarly, while cloud development can be influenced by wind patterns, it does not represent an intrinsic change in wind direction itself; rather, it reflects the conditions in which air rises and cools, leading to condensation. Thus, the presence of a front is the most direct and clear marker of a change in wind direction.