The frigid cold that has set records across the Midwest, stopping trains and planes and driving up energy use, may deliver the coldest day across the U.S. in almost 20 years by a measure of heating demand. Yesterday’s low in Chicago reached a record for the date of minus 16 degrees Fahrenheit (minus 27 Celsius), beating the mark of minus 14 set in 1884 and 1988, according to the National Weather Service. Today, New York’s high will struggle to reach 10 degrees, a day after Central Park reached 50. “It is a pretty ferocious air mass coming down,” said Tom Kines, a meteorologist with AccuWeather Inc. in State College, ... (full story)