Use 'oncoming' to refer to potential danger that is quickly approaching and needs immediate attention. The hikers alerted each other of the oncoming landslide.
Pro Tip 2/3
Visual Perception
'Oncoming' often describes something you can see moving towards you, not abstract concepts. She gazed at the oncoming parade with excitement.
Pro Tip 3/3
Time Sensitivity
'Oncoming' implies a need to be vigilant or to take action due to the proximity of the approach. Drivers should slow down for oncoming traffic in narrow streets.