Air currents and land topography work in tandem to affect rainfall. As wind and air currents blow into areas with higher elevation (for instance the rocky mountains) the moisture in the atmosphere is forced out of the atmosphere and precipitates out as either rain or snowfall. This can also affect the area following an elevated region because after the rainfall, there is not much moisture in the atmosphere so as the air currents continue on after the mountain there is little rainfall in the following area.
Hopefully this helps!
Mar 4th, 2015
Studypool's Notebank makes it easy to buy and sell old notes, study guides, reviews, etc.