Are giant tornadoes in Los Angeles possible as seen in The Day After Tomorrow?

I'm writing a paper on the movie The Day After Tomorrow and my teacher wanted to know if a couple of the weather conditions it showed were possible and why or how. My 3 environmental situations i picked are the tornadoes in LA, the super- cold air that froze everyone and the super- blizzards over the northern hemisphere. If anyone knows if they could happen and why, please answer.