Here are some of the websites I use to forecast/prepare a weathercast.
Computer Models, satellite, radar:
Penn State Ewall
College of Dupage
CoolWx
BUFKIT (Need to download the program)
Weatherunderground
Air Quality:
Dept. of Environmental Protection
UV Index:
NWS UV Index Forecast
Hurricanes:
National Hurricane Center
River Levels, River Forecasts:
Advanced Hydrologic Prediction Service