The long answer requires you tell me what skin are you using.
I have created screens that are called from buttons on my weather screen that loads jpgs snapshots of weather maps for National, regional, and local radar. (Clicking on any pic makes it full screen
If you look closely at the lower right ot the top screen capture, there is a button marked "Animated Weather." This button has a different function on the one day screen and the 5 day screen. On the one day main weather screen it downloads 4 animated gifs (in case I lose internet) that are displayed via the bottom buttons in a IE window.
Animated US Radar:
Notice how the IE window is purposely embedded in the skin. This is what you're looking to do and its easy if you can get the actual internet address of just the map image. If you use the webpage you listed that entire page gets embedded wasting a loy of real-estate on your skin. You have to get just the map.
This is the simple way of doing it, but there is another. Remember, when I said the "Animated Weather" button behaves differently from the 5 day screen. That button calls up an RR Webpage screen with an embedded flash file that accesses an animated regional weather page. This one is really cool because it is not only animated, but also interactive.
This one requires someone write a flash program to capture the animated file.
Hope that helps some.