Why does Ontario get tornadoes?

Most parts of North America get tornadoes. In the eastern portions of Canada and the United States, tornadoes generally happen when a low-pressure systems moves through with an associated cold front, where cool air pushes into moist air, forcing it upward. If the warmer air mass is unstable enough, strong thunderstorms can develop along or ahead of the cold front. If there is sufficient wind shear, or a change in the speed and direction of wind with altitude, the thunderstorms can start to rotate. If the rotation is strong enough the storms become supercells. The rotation can then narrow and intensify to produce a tornado. In other cases the storms may develop into a severe squall line. Spin ups along the line's leading edge or kinks in the line can sometimes produce to rotation needed to produce tornadoes. These, especially spin ups, are generally not as strong as supercell tornadoes.