" In some sense, preparing for wildfires is more like preparing for an earthquake than an approaching storm because of their speed and unpredictability in many cases."

Absolutely. You probably should consider some combination of distance and wind velocity in transitioning between preparedness levels. It is better to leave earlier than later.

I will never forget the smoky, flaming early morning when I couldn't leave my driveway for all the fire engines bumper to bumper straining to get to the advancing fire. Not to worry - it was at least 400 yards away.