In the west, a warmer system will bring snowfall Thursday to higher elevations before a much colder and larger weekend storm produces snow closer to sea level in places like Portland, Oregon and Seattle, where the climatological probabilities of such vacation weather are only 1% to 3%.
“A cold front predicted to move toward the coast this morning and slowly progress through Intermountain West over the next few days will interact with the humidity… to produce heavy snowfall over the high elevation terrain of the Cascades to the Rockies.” , Weather forecast center described Thursday.

The rest of the United States during this time appears to be unusually warm, with record high temperatures expected to fall from Texas to the southeast on Saturday. Southern cities will be 20 degrees above average for this time of year, peaking in the 70s and 80s for the highs – and nearly 90s along the Texas-Mexico border.

In Texas, “while the high temperature records on Christmas Eve are probably untouchable (88 to [Dallas/Fort Worth International Airport] and 91 in Waco), the records on Christmas Day are much more attainable (80 in DFW and 79 in Waco) and look likely to break this Saturday, ”said the National Weather Service in Dallas.

Snow and rain expected in the parched west

Pumping arctic air over the next few days in the Pacific Northwest, coupled with substantial moisture provided by an atmospheric river, could lead to low-level snowfall on Saturday.

The last measurable snowfall on Christmas Day in Seattle was in 2017, with an inch build-up, the National Meteorological Service in Seattle said. The last time measurable snow fell on Christmas Day in Portland was in 2008, although they did have an inch of snow on the ground on Christmas Day in 2017 thanks to a storm the day before.
Check your climatological luck for a white Christmas

The drought-stricken West has already benefited from recent atmospheric riverine events, which transmit streams of moisture to the surface that typically travel thousands of feet in the sky. They are generally 250 to 375 wide and are said to carry an amount of water vapor equivalent to 7.5 to 15 times the average water flow at the mouth of the Mississippi River.

In the Sierra Nevada Mountains, isolated snow could pile up high enough this weekend to reach a building’s second story – up to 10 feet, according to meteorologists from the Sacramento National Weather Service office. .

Over the Sierra Nevada it is possible for more than 5 feet of snow to accumulate until Christmas morning, while more moderate totals of around 1 to 4 feet are expected in the rest of the ranges. mountains of the west, ”he added. prediction center noted.

Snowfall at these levels lead to dangerous road conditions and bad vacations in the area.

“Travel through the Sierra will be difficult at times, if not impossible during the bank holiday weekend,” the Reno Weather Service office said Wednesday morning.

Certain parts of the Intermountain Ouest will also measure snow on their feet, delighting ski enthusiasts.

Those at lower elevations will see about 1 to 3 inches of rain, sometimes heavy, affecting road conditions and potentially causing air travel delays. Flash floods are also possible, and mudslides are always a risk with so much rain.

“Along low-lying coastal areas, this abnormal humidity will translate into heavy rainfall over the next two days, some locations, including terrain adjacent to metro Los Angeles and San Diego, are expected to receive 1 to 3 inches or more of rain in 24 hours “, the prediction center said Thursday.
Track airport delays and travel weather conditions

“Given the potential for flash flooding as well as runoff over nearby burn-scorched and hydrologically sensitive areas, the Weather Prediction Center has issued a slight risk of excessive precipitation for parts of southwestern California. until Saturday morning. “

While this will hamper travel and hamper Christmas plans, rain and snow are a welcome development, given that over 97% of the West remains in drought, even after recent atmospheric rivers – which account for nearly the half of the West Coast’s annual precipitation – – delivered inches of rain and feet of snow.

On a scale of 1 to 5, this week’s atmospheric river is expected to be Category 3 high in California and even 5 in parts of Baja California.

Icy roads and the risk of fire threaten the rest of the United States

Icy conditions on I-94 cause crashes, vehicle runoff in Wisconsin
In the Great Lakes and New England, a pair of systems may have a slight impact on movement with typical winter conditions. Icy roads and dangerous driving conditions were reported in Wisconsin Thursday, with vehicle crashes and leaks along Interstate 94, the state patrol said.

More storm systems are expected to bring rain, winter mix and snow throughout the weekend to the Midwest.

The drought-ravaged southern plains could experience dangerous fires on Friday due to high winds, dry conditions and warm temperatures.

“Conditions will be favorable for the rapid ignition and spread of forest fires, especially near and in the western United States. 281. For this reason, roasting chestnuts on roasts is generally not recommended. a fire open this holiday, “said the Dallas National Weather Service.

Wind alerts are in place for Gusts of 80 mph, which could easily exacerbate forest fires and make highway travel precarious, are expected on Friday.