Tom Skilling's Severe Weather Seminars http://AskTom.org/
Annual seminar on severe weather conducted in conjunction with support and assistance from Fermilab, the National Weather Service, the Severe Storms Forecast Center and others.
Weather By Giannetta http://www.enter.net/~wxdata/
Articles on "Weather and Meteorology," El-Nino, Hurricanes, Tornadoes. Many weather charts/graphics/maps/pictures. Links to other weather sites, some as far away as the South Pole.
Weather One http://www.urbanext.uiuc.edu/weather/
Discusses several topics of weather including clouds, seasons, air pressure, winds, global warming, and violent weather. Also contains activities to give students a hands-on experience with weather.