A massive storm blowing across the country spawned tornadoes that wrecked homes and injured a handful of people in parts of Oklahoma and Texas, including the Dallas-Fort Worth area, as much of the central United States from the Rocky Mountains to the Midwest braced Tuesday for blizzard-like conditions.An area stretching from Montana into western Nebraska and Colorado was under blizzard warnings, and the National Weather Service said that as much as 2 feet 61 centimeters of snow was possible in some areas of western South Dakota and northwestern Nebraska.