Polar vortex chilled central US, downing trees, blasting snow, shuttering schools and causing traffic pile-upsThe next round of bitter cold enveloped the southern US on Tuesday, after the first significant winter storm of the year blasted a huge swath of the country with ice, snow and wind as far south as Florida and Texas.The immense storm system brought disruption over the weekend and on Monday to much of the mid-Atlantic region, triggering the announcement of states of emergency in several states. It even hit areas of the country that usually escape winter’s wrath, downing trees in some southern states, threatening a freeze in Florida and causing people in Dallas to dip deep into their wardrobes for hats and gloves. Continue reading...