Climate Central: From blooming flowers to twittering birds, the signs of spring are popping up and the miseries of winter are becoming a distant memory for many. But not for some climate scientists. The curiosity of a growing group of researchers has been piqued by the tenacious temperature divide that has separated East from West over the past two winters as a wild zigzag of the jet stream has brought repeated bouts of Arctic air and snow to the East and kept the drought-plagued West baking under a record-breaking...