The bitter cold accompanying this powerful winter storm broke some long-standing record lows for parts of Montana and Wyoming. Casper, Wyoming, saw its coldest day ever on Thursday as temps plummeted to a bone-chilling 42 degrees F below. It was also a Casper record for Dec. 22, with the old record of 33 below set in 1983. Other areas breaking records Thursday included Riverton, Wyoming, which dropped to 31 degrees below, shattering a 24-year record.