How would the climate of the Americas change if the Rockies and Andes mountain ranges were located on the Eastern Coast? (precipitation, cities)

[Raysuxx]

Rain shadows and orographic precipitation would be changed drastically I imagine, as would the climate of many cities. Anyone want to hazard a guess at how the movement of these ranges would affect the climate of the Americas and some of the major cities?

[ProtoStrata]

Well, the Rockies aren't the only mountains that impact North America's weather. The Sierra Nevada, Cascades, and Coast Ranges create more significant rain shadows than the Rockies. But assuming the Rockies were located somewhere in the center of North America (extending from southern Texas to northwest Ontario) and that the elevations of the east and west coast ranges were swapped, North America would probably be wetter overall. The southwest would still be arid/semi-arid, of course, but more moisture would reach the interior northwest with the neutered rain shadow of the Cascades. The actual Rockies and western ranges inhibit the movement of polar air masses during the winter into the western U.S., so the climate of western North America would be more continental. California, though still Mediterranean, would experience more extreme winters low, similar to the southeastern U.S. Oregon, Washington, and British Columbia would still experience oceanic climates, but more like central Europe. The Rockies, being in the center of the continent, would receive more gulf moisture and would be much more lush than they are now.

If the Andes were situated on the east coast of South America, the interior of the continent would probably be much more arid, like the Atacama Desert and coastal Peru, but over a much larger area and much hotter. Conditions within 25 degrees N or S of the equator would probably become wetter moving from the mountains towards the west coast, but not substantially. An east-west Amazon river system, if it existed at all, would be tiny. The majority of Patagonia would lie west of the Andes, which means that there would be more fertile, flat land in southern South America.