I found a great one to share with you that works with network atlas, it may say linked background failed, but go ahead and save it then look on solarwinds. The size is really good and much better than that weather underground one. And yes it updates every 10-15 min.
http://archive.khou.com/weather/images/core/animated-loops/comp/1280x720/usa_anim.gif
I was wondering though if any of you know any weather radar sites that have a map for weather for each state separately??