Maldonado, Uruguay

At a Glance Wednesday marked the 13th consecutive day with eight or more reported tornadoes. The jet stream has been stuck, leading to more supercell thunderstorms.Researchers can't say what, if any, effect global warming has on individual tornadoes. Tornadoes have been wreaking havoc over much of the United States for the past two weeks, and the daily drumbeat of destruction has some wondering if climate change is to blame. Wednesday marked the 13th consecutive day with at least eight reported...