This holiday weekend is a tale of two Christmases: Heavy snow, rain and wind are forecast for the entire US West Coast, while potentially record-breaking warmth will toast the South.
Out West, a warmer system will bring snowfall Thursday to the highest elevations before a much colder and more significant weekend storm could deliver snow closer to sea level in places like Portland, Oregon, and Seattle, where the climatological odds of such holiday weather are just 1% to 3%.
The rest of the United States over this period looks to be unseasonably warm, with high temperature records set to fall Saturday from Texas into the Southeast. Cities in the South will reach 20 degrees above average for this time of the year, topping out in the 70s and 80s for highs — and near 90 along the Texan-Mexican border.
In Texas, “while Christmas Eve high temperature records are likely untouchable (88 at [Dallas/Fort Worth International Airport] and 91 at Waco), records on Christmas Day are much more attainable (80 at DFW and 79 at Waco) and appear likely to break this Saturday,” the National Weather Service in Dallas said.
The drought-strained West already has benefited from recent atmospheric river events, which deliver to the surface flows of moisture that usually travel thousands of feet in the sky. They tend to be 250 to 375 miles wide and are said to transport an amount of water vapor equivalent to 7.5 to 15 times the average flow of water at the mouth of the Mississippi River.In the Sierra Nevada mountains, isolated snow could pile high enough this weekend to reach the second story of a building — up to 10 feet, according to meteorologists at the Sacramento National Weather Service office.
“Over the Sierra Nevada there is potential for 5+ feet of snow to accumulate through Christmas morning, while more moderate totals of around 1 to 4 feet are expected across the rest of the western mountain ranges,” the prediction center said.Snowfall at these levels would make for hazardous road conditions and poor holiday travel across the region.