Answer by  
                                                                                          HotelWhiskey (19)
                                                            
                          
                          
                                                          When there is no discernible difference between two air masses, a stationary front or stationary boundary is formed. Often times this front shows very little movement. This is due to the large, semi-permanent air masses that it separates. An example of this would be a stationary front trailing a cold front that separates two areas of high pressure.