Revealing mistake: When the tornadoes are hitting Los Angeles you hear a woman say,'Is anyone hurt?' The angle is high and you can see the Capitol Records building, the tornado and the helicopter. If you look very closely at the bottom right you see lots of cars on the road driving like mad and one of them drives under a large truck trailer, betraying that they are CG cars. (00:26:35)
Revealing mistake: When a newscaster is mentioning that two airplanes were caught up in the storm and crashed, they show footage of the AVIANCA (Colombian airline) Flight number 52, which crashed in New York on January 25th, 1990. (00:30:00)
Revealing mistake: Very near the end of the movie, when the NOAA director is viewed in the helicopter as it approaches NYC, the image is reversed, verified by the David Clark logo on his headset being reversed. There are two different shots of this just a few seconds apart, and they are both reversed.
Revealing mistake: During the tornado scene there is a part where you see lots of cars on the highway flying and crashing and if you look carefully at the second car falling it doesn't touch the ground, yet it manages to cause sparks and dents.
Revealing mistake: In the scene where Dennis Quaid jumps over the ice crevasse to the other side, note the position of his ice axe, which is strapped to the right side of his hip. When he jumps back over with the metal tubes in his hands, he balances a little, then falls. We see his gloved hands disappear as he falls into the crevasse. The next shot shows he is holding onto the ice axe, which is embedded into the ice with his left hand. In reality he would not be able to unhook the ice axe so quickly and then put it in his left hand and thrust it into the ice. Remember what gravity does.
Answer: Antarctica.
Friso94