".....many times the two sides were more interested in killing each other than swapping meteorological knowledge."

That is so true. I have never seen a western where settlers and Native Americans exchanged detailed historical meteorological data.

There is a large ocean just west of California/Oregon/Washington. Desalinization is very expensive, uses a lot of power, and creates waste products that would hard to get rid of. But either desalinization or a drastic drop in population will have to happen as the west continues to be aridified.