• photography
• chase logs
• weather
• links

• storm chasing
• weather
• photography

forecasts

• Weather.gov
  Home of the National Weather Service, the best source for forecasts in the U.S.
• Weather Underground
  Excellent site for viewing current conditions, NWS forecasts and more.
• Storm Prediction Center
  NOAA unit responsible for issuing severe weather watches, as well as many other convective products.

model data

• pivotalweather.com (weather forecast model maps)
  Large, fast-updating graphics for virtually all major NWP models.
• NCEP Model Graphics
  Official source for NCEP model output.

observations

• RAP Real-Time Weather
  Nice, large graphics for surface observations, upper-air charts and more.
• CoD Satellite
  My personal favorite source for satellite images.
• SPC Mesoanalysis
  High-quality graphics for a myriad of meteorological fields, derived from the latest RAP analysis.