I've always found wind chill as informative as I needed. When I was in the AF, we used wind chill as ways to determine the length of time we would allow folks to work on the flightline. Below a certain wind chill factor, only work inside or inside the aircraft was allowed. I don't think his vernacular allows for the fidelity I'd like. Where does the extreme cold alert begin? -20? -30? Is that with the wind being factored in? It makes a difference. Not convinced based upon his explanation.