Most of the precipitation for the region east of the Rocky Mountains comes from:

Question

Quizplus · Accepted Answer

Most of the precipitation for the region east of the Rocky Mountains comes from mT (maritime tropical) air masses. These air masses originate over the Gulf of Mexico and the Atlantic Ocean, and they bring warm, moist air that often leads to the development of thunderstorms and heavy precipitation in this region. Modified mP (maritime polar) air masses may also contribute to precipitation in some areas, but they are not as dominant as mT air masses. mA (maritime arctic) air masses are generally too cold and dry to produce significant precipitation in this region. Evaporation from soils and vegetation is not a primary source of precipitation, as it is only a small fraction of the water cycle.

Most of the Precipitation for the Region East of the Rocky