With Frances slowly trundling over Florida, hurricanes seem to be the theme of the day and it brings to mind by favourite movie on this subject, John Ford's 1937 The Hurricane. (Of course, there's also Key Largo.)
The movie climaxes with what may be my favourite special effects sequence, certainly one of the best on film. It's all the more amazing because it's from 1937.
(It should be said, however, special effects are helped greatly by being in black and white.)