Seventy-five percent of the world’s tornadoes occur in the united states during the late spring and early summer months, when warm moist air from the tropics rises to meet cold air descending from canada. as the warm tropical air rises, it condenses quickly into cumulus clouds. cumulus clouds can then evolve into cumulonimbus clouds, which eventually can form super cells (thunderstorms). wind moving in various directions causes the condensing air to spin like a top. if the resulting funnel is able to stretch between the bottom of the cloud and the ground, it becomes a tornado. which of the following would increase the intensity of the tornado? a. decrease in wind speed b. decrease in condensation c. increase of cold air d. increased rate of evaporation