The next two weeks will feature multiple "powerhouse" storm systems and a polar vortex event that together will affect the U.S. from coast to coast, snarling travel, threatening lives and causing damage. Threat level: The first storm is poised to bring multiple hazards from Monday through Wednesday, including a "ferocious blizzard" in the Plains, plus torrential rain, severe weather and high winds on the Gulf and East Coasts. • Some of the upcoming extremes have clear ties to climate change. The warm side of this first in a series of storms is where heavy rain, severe thunderstorms including a strong tornado risk, ... (full story)