What characterizes a stationary front?

A stationary front is characterized by a frontal boundary between two air masses that show minimal horizontal movement over time. This situation occurs when neither the warm air mass nor the cold air mass is strong enough to replace the other. As a result, the weather conditions associated with a stationary front can persist for an extended period, leading to prolonged clouds, precipitation, and sometimes fog, depending on the moisture content of the air masses involved.

In contrast, a rapid shift in weather indicative of strong movement would pertain more to a cold or warm front, where significant changes in temperature and weather conditions occur quickly. A combination of warm and cold fronts moving together typically relates to occluded fronts rather than stationary fronts. Lastly, a constantly shifting boundary resembles the behavior of a warm or cold front, where air masses are actively displacing each other. Therefore, the defining aspect of a stationary front is its relative lack of movement, which makes option B the correct characterization.