The thing is: There really isn't a border. How the local weather is displayed is determined by your cable/sat TV provider. Mine chooses to smush the screen - you get the full view, but it is smaller to provide local info.
The cable company gives a full screen, but with a blue bar at the bottom of the screen - which does block the lower portion of the screen. Take the comparison of the desk shot in my caps, and this one, courtesy of Kim's Yahoo! fan group for an example.
I prefer the shrunk screen to the cut screen.
