A stationary front is a boundary between two air masses that have different temperatures. They are either stalled, or moving slowly. Winds are parallel along a stationary front. If the winds in one air mass shift, the stationary front will become either a cold front or a warm front. The weather along a stationary front is usually clear to partly cloudy. Though if there is enough moisture, clouds and rain can form, and rain will continue to fall as long as the front is in one place.