From nbc news World Headquarters in new york, this is nbc nightly news with lester holt. Good evening, im Peter Alexander, in tonight for lester. For millions of americans at the end of the long Holiday Weekend, the weather is a top concern tonight. Already the post christmas rush is off to a slow start after whiteout conditions and fierce winds in parts of the plains and upper midwest. And freezing rain that could complicate travel in the northeast. Tonight for the first time, were also hearing one mothers incredible survival story, hiking 26 miles in the snow after her familys car got trapped near the grand canyon. Dave gutierrez is tracking the worst of the weather tonight. Reporter tonight the upper midwest is digging out after a relentless christmas blizzard. How the heck am i getting out of here . Reporter many roads in the dakotas, impassable. 240 miles of i94 shut down. A foot of snow blanketed bismarck. While treacherous wind, snarled air traffic. We pulled up to check our bag