What is the scope and impact of the current winter storm in the United States?

The current winter storm is affecting 100 million Americans across 25 states, with severe weather conditions extending from Montana down to Texas and eastward to the mid-Atlantic region. The storm is bringing dangerous snow and ice accumulation to multiple regions, creating hazardous travel conditions with ice-covered roads in Oklahoma City where a semi-truck was reported sideways on Interstate 40. Extreme cold temperatures accompany this weather system, with wind chills plummeting to 21 degrees below zero in Chicago and feeling like just 1 degree in Dallas. Whiteout conditions have been reported in Oswego County, New York, with lake effect snow expected to continue through the following morning, creating widespread dangerous winter conditions throughout much of the country.