The Weather Underground ("Wunderground") has long been one of my favorite weather sites. Lot of info at its main site.
I recently saw the Wunderground app running on an iPad, and was surprised to see that a much more detailed and colorful map was apparently available for the iPad than for the PC. So I wrote to the site and asked if I could get that same map through a regular browser.
Here's the answer.
(click and slide to move the map around, zoom controls on the left.)