Mountain passes and higher elevations in Washington and Oregon are in line for heavy snow, with some flakes also forecast for Seattle and Portland. File Photo by Ken Cedeno/UPI | License Photo
Frigid air will precede a wintry storm bringing heavy snow to the higher elevations of Washington and Oregon starting Saturday night, with some possible in Seattle and Portland.
Snow could fall close to sea level in the region next week as even colder air pours in across much of the West, AccuWeather meteorologists say.
The stormy weather will follow a spell of benign weather conditions. A beautiful Thanksgiving Day is in store for much of the Northwest with mild air, areas of sunshine and light winds making for good travel conditions for those visiting relatives for the holiday.
Typical highs around Thanksgiving range from the mid-30s Fahrenheit in the Washington passes to near 40 in eastern Washington and Oregon to the low 50s at sea level along the Northwest coast.
"Mild air has been very difficult to come by so far this month across the Northwest, with many interior locales averaging between 8 and 12 degrees below average through the first three weeks of November," AccuWeather Long-Range Meteorologist Brandon Buckingham said.
Temperatures have averaged 3-6 degrees below normal during the first three weeks of November along the Interstate 5 corridor of Washington and Oregon.
"The only exception to favorable weather conditions for travel in the Northwest will be patchy fog Thursday morning in the I-5 corridor," AccuWeather Senior Meteorologist Dave Houk said. "There is a chance of slippery spots on bridges where temperature dip close to freezing."
However, the atmosphere will change gears to a stormier and more wintry pattern starting this weekend.
A cold front will start to push through the region on Friday with low-elevation rain showers and mixed rain and snow showers that will end as a bit of snow over the Cascades and mountain passes during the evening.
|This image of the northern Pacific Ocean was captured on Wednesday, Nov. 23, 2022. (AccuWeather Enhanced RealVue&trade satellite)|
Two storms were lining up over the northern Pacific on Wednesday. With cold air in place as the first of two storms arrives later Saturday and Saturday night, snow will begin to fall over the mountains and passes.
"Between Saturday night and Sunday, rain and mountain snow can begin to expand in coverage across Washington, Oregon, Idaho and western Montana," Buckingham said.
Travel over Snoqualmie and Stevens passes may become difficult by Sunday with the risk of the passes closing for a time due to rapidly accumulating snow and slippery driving conditions. There is the potential for several inches to a foot or more of snow to pile up at pass level by late Sunday in the Cascades of Washington and northern Oregon.
A few inches of snow may fall on Spokane, Wash., and northern Idaho along Interstate 90, as well as over the Blue Mountains and portions of I-84 in northeastern Oregon on Sunday.
In order to reduce the risk of delays and accidents, motorists may want to consider adjusting their travel dates to before or after the snowstorm moves through, forecasters say.
"Progressing into early next week, nearly every location along and west of the Colorado Front Range will feel the effects of this storm," Buckingham said. During Sunday night and Monday, a mixture of rain and snow is in store for the Salt Lake City area as mostly snow falls around Boise, Idaho.
Cold Canadian air will likely be forced southward over much of the western U.S. to close out the month of November, and it will stick around into early December. Temperatures during this time will average 8-15 degrees below average, Buckingham said.
During much of next week, high temperatures in Seattle will range from the mid-30s to near 40. Farther inland, highs in Spokane will trend downward from near freezing on Monday to the low 20s by the first weekend of December.
The combination of cold air and lingering moisture can lead to rain and wet snow showers along the I-5 corridor of Washington and northern Oregon from this upcoming Monday to Tuesday.
The second storm is forecast to drop southward along the Pacific coast from the middle to latter stages of the week.
A typical storm track in the Northwest during this time of year is usually accompanied by milder air. However, with the air being so cold and extensive, snow levels may be rather low in the Northwest. A wintry mix is possible at the onset of the storm on Wednesday even near sea level, prior to transitioning to rain. Accumulating snow cannot be ruled out over the hilltops in the I-5 corridor this far in advance, according to AccuWeather meteorologists.
It is possible that this second storm may push significant rain and mountain snow all the way to Southern California during early December.
"While the persistent chill and upcoming much colder conditions may not be appreciated by residents due to the high energy demand for heating, ski resort operators in much of the West will relish in the fact that they will be able to continue to add to the snowpack amid subfreezing temperatures," Buckingham said.
AccuWeather's team of long-range meteorologists predicted a fruitful and early start to the ski season in the Cascades and Rockies when it released its winter forecast in September.