CGI and cinematic depiction of freak weather events go together like apples and oranges. Films such as Twister, The Day After Tomorrow, Deep Impact and The Perfect Storm have used computer generated tornados, tidal waves and other phenomena to great effect.
Cloudy With A Chance Of Meatballs may just be the CGI weather blockbuster to rule them all. It's a children's film with a witty script, a sharp message about junk food, greed and waste, and possibly the best simulation of a spaghetti twister I've seen all year. There are also some subtle-ish nods to Independence Day as well as many of the features above.
If you enjoyed the film, check out the concept art at io9.