Wintertime mP air masses are less common along the Atlantic coast of North America than along the Pacific coast mainly because
A) the water is colder along the Pacific coast.
B) the prevailing winds aloft are westerly.
C) the source region for mP air on the Atlantic coast is western Europe.
D) the water is warmer along the Atlantic coast.
E) the land is colder along the Atlantic coast.

Question

Quizplus · Accepted Answer

The prevailing winds aloft are westerly along the Atlantic coast, which means that any air masses that originate in the Pacific and move eastward will be blocked from reaching the Atlantic coast. Meanwhile, wintertime mP air masses are more likely to come from the west in the Pacific region, making them more prevalent along the coast. The temperature of the water or land is not a significant factor in determining the prevalence of mP air masses. The source region for mP air on the Atlantic coast is mainly Canada or the North Atlantic, not western Europe.

Wintertime MP Air Masses Are Less Common Along the Atlantic