Question 1:
The jet stream plays a major role in the location of mid-latitude cyclones. The jet stream brings down colder air from the north into the southern regions of the United States. A front separates these two air masses. The low pressure system forms to the east of the upper-level trough of the jet stream.
Question 2:
Most tornadoes are found in the Great Plains of the central United States – an ideal environment for the formation of severe thunderstorms. In this area, known as Tornado Alley, storms are caused when dry cold air moving south from Canada meets warm moist air traveling north from the Gulf of Mexico.