Let's suppose I'm high in the mountains, it's a little cloudy, and I want to go back down. The pressure would rise as the altitude decreases. Let's say more clouds gather up for a storm (but I can't notice them because the sky was already cloudy), hence the pressure decreases. What would a Pathfinder show me? Is there any chance it might show me a constant or slightly increasing pressure (leading me to believe that the weather could actually improve)? I don't think the temperature could be such a big deal maybe I'm literally chilling out as I go downslope. So could this happen?
Or would the air pressure actually go down because of the bad weather? Are clouds a much more powerful pressure modifier than the descent speed I could achieve on foot? But what if I was on my bike, or in a car and I would have descended more rapidly? The actual formula on which those calculations are made would be useful.
Sorry for not beeing more explicit, hope you understood my question and I'm looking forward on your answers. Some sort of mathematic understanding of those relationships would be useful.