http://weatherlabs.planet-science.com/weather-forecasts/using-a-computer-to-predict-the-weather.aspx
USA Today Forecasters Rely on computer Models
http://usatoday30.usatoday.com/weather/wmodels.htm
Live Science
http://www.livescience.com/39135-incredible-technology-how-to-forecast-severe-storms.html
If you have extra class time...
http://discoverykids.com/?s=hurricane