[sp332]

Chaos theory does not mean that literally anything can happen. Weather changes are still bounded by energy inputs and outputs. It can't rain if the humidity in the air is too low. The jetstream isn't just going to reverse course anytime soon, although it is shifting slowly. It's physically impossible to have snow if the weather is too warm - complex dynamics can't change that. I'm not saying a forecast will never be wrong, but not every case is an edge case. With good data and a useful model, you can be right most of the time.