August 21, 1996?

Okay, this link is old. But since VFX and science are both built on what came before, it's still very relevant.

http://library.thinkquest.org/3496/twister.html

It's a great page about much of the problem solving and process used to create the tornadoes in the film Twister. Weather is someone we are all familiar with and have a strong mental image of what real storms, tornadoes, hurricanes, etc. look like. So to duplicate them well digitally requires a lot of painstaking research.

What seems interesting is it's the little extras that really make it believable. People didn't notice the tornadoes in Twister as much as the noticed the flotsam and jetsam that was thrown about by the tornadoes (everyone remembers the cows). This carries over to The Day After Tomorrow (TDAT), of all the LA-ravaging tornadoes in TDAT, the ones that really seems convincing are the ones ripping about objects like the Capitol Records building.