Overview
- The National Weather Service has issued winter alerts across 19 states and Washington, D.C., with officials warning of hazardous travel and life‑threatening wind chills.
- Snow is forecast to fall Saturday night into Sunday along a broad swath from the northern Plains to southern New England, with typical totals of about 1–6 inches and locally higher bands.
- Mountains and high terrain face the heaviest snowfall, with localized totals near 30 inches in parts of Alaska and the West and heightened avalanche danger in backcountry areas.
- Cold air surges in behind the storm late Sunday into Monday, driving temperatures 15–30 degrees below normal and pushing wind chills to subzero levels, including values near or below −30°F in parts of the Upper Midwest.
- A rapid warmup is expected by midweek for much of the U.S., and U.K. model guidance hints at a separate wintry spell around Dec. 19 that remains uncertain.