Some interesting weather sites:

http://www.ducksters.com/science/earth_science/weather_forecasting.php

http://pbskids.org/dragonflytv/show/forecasting.html

http://easyscienceforkids.com/understanding-the-weather-forecast/

http://www.weatherwizkids.com/weather-folklore.htm

http://www.almanac.com/content/weather-proverbs-and-prognostics-animals