CAROL COSTELLO, CNN ANCHOR: Just when people in the eastern half of the country thought spring had sprung, winter is back with a wallop. CNN's Lisa Leiter reports on the return of snow.</s>LISA LEITER, CNN CORRESPONDENT (voice-over): The first big winter blast dumped a foot of snow on Chicago, interrupting one of the warmest and dries winters on record.</s>TOM SKILLING, METEOROLOGIST: Virtually, the entire area east of the Rockies has had had -- except for the Northern Plains, like the Dakotas -- has had what can be described as an unusually mild winter. And snowfall has been a fraction of what's been normal in many of those areas.</s>LEITER: In Kansas City, heavy ice weighed on tree branches, snapping power lines and leaving 100,000 people without electricity. One official said, "It's the worst storm the city has ever seen." The snow even took Detroit by surprise, causing dozens of car accidents there. And the snow frustrated thousands of air travelers. United Airlines canceled more than a third of its flights out of O'Hare Airport and delayed most others an hour or two. (on camera): It's not so unusual that a foot of snow would blanket Chicago at the end of January. What is strange is that just four days ago it was a near record 61 degrees. And people were in this park in short sleeves. (voice-over): So exactly what is behind this weird weather?</s>JOSEPH D'ALEO, METEOROLOGIST: The sun is one of the key factors so far this winter. The sun has re-surged to a new peak in this current 11-year cycle. And at these high levels of solar activity, the sun is a little brighter, a little warmer. And the result is, of course, much of the country, temperatures are above normal.</s>LEITER: For farmers, warm winters are more productive ones. They can work in the fields and the livestock can stay outdoors. But they may be inside before too long. Meteorologists are not ruling out a frigid and snowy end to this mild winter. Lisa Leiter, CNN Financial News.
Despite Recent High Temperatures, Snow and Cold May Soon Return