Fronts and Lows â¢ Occluded front: when a cold front âcatches upâ to a warm front. This happens because cold fronts typically moves twice as fast as warm fronts. â¢ Stationary front: is a front that is not moving forward. This occurs because the approaching warm front is not strong enough to force the cold front to continue its forward motion. â If a stationary front remains stationary for too long, flooding can occur.