That's because of "another atmospheric river event" that will bring copious rainfall to coastal and valley locations and 3 to 4 feet of snow to the Sierra, forecasters said. The storm will move into the Rockies by midweek: "One tricky travel area will be in and around the Denver area as snow spreads across the area on Wednesday,

The holiday travel rush is expected to be bigger than ever this year, and staffing shortages and weather can lead to delays.