"Tornado Alley
The Midwestern United States is home to "Tornado Alley," a portion of Texas, Oklahoma, Kansas, and Nebraska commonly plagued with powerful and plentiful tornadoes. Tornado Alley is located at a point where the jet stream drives cool, dry, high-pressure air masses from the deserts and mountains of the West toward the East Coast."
When the cool, dry, high-pressure system moves into "Tornado Alley", which type of air mass does it run into where a tornado could be the result?