I’ve used a few different desktop weather applications (and recently some mobile ones) to get the lowdown on what’s really coming my way during inclement weather.  What I usually look at is the Doppler radar which paints a pretty good picture of what precipitation one can expect.  As per usual, Google (GOOG) is now one-upping the ante on those products.  You’ve been able to see weather in Earth since 2007, but now you can actually see that view that you see on TV weather forcasts:

The only downside is that this layer isn’t available for Earth on mobile devices yet.  I’m sure it is on the drawing board.