The phrase "___ is coming up" means that something is scheduled, and is going to happen soon:

Sorry, I can't. Final exams are coming up in a couple of weeks.

Our anniversary is coming up soon.

The final deadline is coming up at the end of this month.

These examples are all about events that are scheduled for a certain day. But you wouldn't use "coming up" to talk about things that you're not sure about, like an earthquake.