Since stationary fronts move very slowly or not at all, it can help predict longer term weather.
Fronts mark the boundary between two air masses. A stationary front is the boundary between two different air masses with different densities when neither is advancing. The air masses are not moving strongly enough to overtake each other, so the front remains in one place.
Winds along a stationary front are usually parallel to the front blowing in opposite directions on either side which is one reason why the front does not move.
When one of the air masses moves into the other air mass, the stationary front will begin to move. When this transition occurs, the front will then either be classified as a warm front or a cold front, depending on which air mass is pushing ahead.
So, you want to be a weatherman? Learn how to become a climatologist at Study.com.