Got this link from the firstname.lastname@example.org list. It illustrates the micrometeorology over a large mountain range such as the sierra nevada. How quickly one can go from hero to zero. Airmasses of different temperatures and traveling in different directions at altitude can have profound effects on a pilot's flight path. Unfortunately, air is invisible and you only know it when youre in it. Planning for both the best and the worst can help you make it home for dinner.
Nevada Triangle vid.