The high incidence of tornadoes over the central portions of North America: a. Is related to the continent's geographic setting, that favors the occurance of potentially unstable conditions over this region. b. Is caused by the low friction over the region due to its flat terrain. c. Is mostly related to the above average values of the Coriolis force over this portion of the world.
d. Is a direct result of moisture adveted by the area by hurricanes coming from the Gulf of Mexico
