What causes the tornadoes at tornado ally? What circumstances led to all the tornadoes in April 2011?

1: 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. Tornadoes can form at any time of year, but most occur in the spring and summer months along with thunderstorms.

2: On March 29, a warm front over the Gulf of Mexico associated with an upper-level low over Texas moved northward into the Gulf Coast States, bringing scattered severe weather. In Louisiana, three tornadoes touched down, including an EF1 which caused a three-story building to collapse.
BRAINLIEST PLEASE! ❤️