Add Yahoo as a preferred source to see more of our stories on Google. An imposing, ominous shelf cloud was spotted in the skies above Chicago. The cloud is a sign of severe thunderstorms and you ...

At first glance, the shelf cloud that passed through the skies of Chicago on Wednesday morning looked like something out of "Independence Day." But don't worry — this ominous-looking formation isn't ...

An imposing, ominous shelf cloud was spotted in the skies above Chicago. The cloud is a sign of severe thunderstorms and you should take shelter if one is coming your way. Video shows the cloud moving ...