Burst of Arctic air, snow on the way for the western US
A major outbreak of cold, stormy weather could snarl travel at higher elevations of the northwest United States and British Columbia this week, AccuWeather meteorologists say. The pattern will hit close to the one-year mark from a cold wave in 2022.
"During last year's cold and snowy outbreak, Seattle set a record low of 23 degrees on Feb. 23," AccuWeather Meteorologist Joseph Bauer said.
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The jet stream is preparing to make a major southward lunge along the West Coast of North America starting on Sunday and continuing well into this week. This shift will set into motion features in the lower part of the atmosphere that will bring frigid conditions for late winter to much of the West.
"High pressure building southward from Alaska, combined with a storm near Hudson Bay, Canada, will help to pull Arctic air southward across western and central Canada and into the Northwestern and North Central states," Bauer said.
Temperatures could be as much as 25-50 degrees Fahrenheit below historical averages, and feet of snow could pile up in some of the mountains of the western U.S., Bauer added.
The core of the deep freeze is likely to occur from Wednesday, Feb. 22, through Saturday, Feb. 25, when temperature records are most likely to be challenged along the Pacific coast. However, subsequent rounds of cold air will follow into early March.
One or more storm systems will pivot from the Pacific to the interior western United States from early this week through the end of the month and beyond. Each storm will bring rounds of snow, gusty winds and reinforcing bursts of cold air.
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"Feet of snow can pile up in the Cascades, the Sierra Nevada and over some of the various ranges of the Intermountain West this week and the following weekend," Bauer said.
Accumulating snow is possible along the Interstate 5 corridor, including in Seattle and Portland, in the Northwest. The exact storm track will determine precisely when and where snow falls in lower elevations of the region.
The magnitude of gusty winds, combined with blowing and drifting snow over the mountains and passes, could pose a major problem for regional highway and rail traffic. Strong winds from the storms could lead to vehicle rollovers. Periodic airline delays and flight cancellations are likely at some of the major hubs in the Northwest and interior West as the pattern ramps up.
The same pattern that will hit the Northwest hard will also bring significant impacts to the Southwest, including Central and Southern California, from late in the week through early March. Low snow levels could bring rounds of accumulating snow to the passes, including over the Grapevine, just north of Los Angeles.
While the amount of rain is still questionable for low-elevation locations in California, there is little doubt that the stormy and cold pattern will provide a boost to existing snow cover and vital runoff this spring over the Sierra Nevada and other ranges in the West.
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