In a nutshell, you'd have to know the time that the "event" will arrive or at least a good approximation, compare that with the time you'll need to do whatever you want to do, when the arrival time coincides with your preparation time, do whatever you plan on doing.

In other words, if you know it will take you an hour to bug out and your best guess is that the "event" is one hour away from happening, activate your plan.

Asking what things need to be known in every possible scenario is a huge job.

What you want to know is a full time job for many people, how can you expect to learn about fire behaviour, meteorology, fluid mechanics, engineering standards, and all of the other things that you'd need to know in order to make a decision about any given situation that might occur? It's impossible.

I know for a fact that firefighters are taught about specific things to watch for before making their decision to bail out, I also know that they routinely ignore those things as do many professionals. They take their entire body of knowledge and then make a subjective decision on the fly all the time. Which is one reason why I got caught taking cover under a fire truck during a wildfire once. Even the folks who do this stuff for a living can't know all the things that might happen.

Using a wild fire as an example, knowing that a fire is a particular distance away is only one piece of data, in order to make a well reasoned decision about when to evacuate you'd need to know the wind direction and speed, the terrain between you and the fire, the fuel load of the terrain, the number and type of any structures between you and the fire, the current and predicted weather conditions, the manpower available to get between you and the fire, the technical resources available and a few other things I'm probably forgetting. Wouldn't it be smarter to have a plan that says that if a wildfire gets within a given distance to you to evacuate? You can overanalyze yourself to death. Literally. In the time you take trying to make the BEST response, you can die. I'd rather over-react then under-react.

I might be wrong but I don't think anyone posting here would be able to give anyone specific guidelines on what to do for every possible scenario. And frankly,
I'd be very cautious in believing anyone who claims that they could do so. I've worked at a few emergency operations and controlled chaos is the best way to describe most of them. One need look no further then the recent Station Fire here in SoCal to see where otherwise intelligent, highly trained people made some fundamental errors in judgement about how and where to fight the fire. If the experts can get it wrong, how can a lay person expect to know all the stuff needed in all of the scenarios listed earlier? It really is very subjective.