Winter weather may have retreated across much of the central and eastern United States, but parts of the Upper Midwest and areas along the Canada border in the Northeast face more rounds of snow and ice this week. Enough will occur to create travel problems and possibly cause power outages. Part of the same storm breaking down the two-week-long record heat wave in parts of the West will track toward the Upper Midwest by midweek. At the same time, a fresh surge of cold air will push southward