Imminence is when something is just about to occur. You might talk about the imminence of snow on a cold, cloudy winter morning.
The noun imminence is good for describing the quality of something that's likely to happen soon. It comes from the adjective imminent, or "about to happen." A small country might worry about the imminence of invasion from a larger country, or you could predict the imminence of your dog running to bark at the door after hearing him growl at a noise outside. The Latin root word is imminere, "to overhang, impend, or be near."