The National Weather Service has an online photo library of historical meterological events, such as this 1969 picture at right of a waterspout photographed from an airplane off the Florida Keys. Other images include lightning storms in Boston, the Great Dustbowl of 1935, and colorful aurora australis photographed at the South Pole station. One of the oldest historical storm records on the website is a 1772 letter from Alexander Hamilton to his father recounting a hurricane that passed overhead in St. Croix. The NWS album is part of a larger NOAA photo library of over 20,000 images. Unfortunately, the site design itself is rather dated (they use tables!!), and the album website isn't as easily searched as, say, Flickr, but it's a great site for free, publicly available, uncopyrighted images.