When it became clear that the conditions over Moore, Okla. were ripe for a huge tornado, the National Oceanic and Atmospheric Administration put its GOES-13 satellite into high gear.
Instead of imaging the earth every 30 minutes, it was doing it every 5 minutes. The images it beamed back are stunning. Here's a time-lapse video that NOAA put together and released today:
NOAA says that their GOES-15, which sits over the Western U.S. and Pacific, was taking pictures at 1-minute intervals. Here are images from that satellite: