[Dach]

Meh, it's only a cool idea when you aren't doing anything and one occurs. If you are in the middle of something important, and a tornado runs across your level or an earthquake hits, it sucks. Granted you can have it affect the monsters so they are also affected, thus releving some of the problematic situations, but not all of them. Overall, it'd be fine if there is some kind of forewarning like a storm, tornadoes and floods don't appear out of nowhere. Earthquakes do, but they don't last very long. Point being, do it right if it is done at all.