Accumulating snow on the way for Seattle, Portland
A state of emergency has been declared for Oregon residents through January 3rd as a result of the winter weather hazards.
By
Renee Duff, AccuWeather senior meteorologist
Published Dec 23, 2021 1:20 PM EDT
|
Updated Dec 26, 2021 4:04 AM EDT
While the weather in some parts of the United States may have people thinking it's spring, forecasters say residents in the Pacific Northwest will certainly know which season it is into the last week of 2021.
Mother Nature will be providing a late snowy Christmas gift to residents in Seattle and Portland, Oregon, as frigid air rushing into the region will mesh with waves of moisture. Although some Northwest residents may get more than what they bargained for as a state of emergency was declared for Oregon from Christmas Eve through Jan. 3rd due to the expected cold and snow.
The two temperate cities see much more rain than snow most years, with average snowfall totals standing at a mere 4.3 inches for Portland and 6.3 inches in Seattle. But this holiday season, snow won't be exclusively for the region's mountainous areas.
"Bitterly cold Siberian air began to rush southward across British Columbia and Alberta, Canada, at the end of the week, dropping temperatures 15-30 degrees Fahrenheit (8-16 degrees Celsius) below average," AccuWeather Meteorologist Jessica Storm said. "This chill is anticipated to spill over the Canada-U.S. border by early in the coming week, bringing shiver-worthy weather to the Northwest."
"Snow levels can drop close to valley floors, possibly yielding accumulating snow for the I-5 corridor between Seattle and Portland," AccuWeather Lead Long-Range Meteorologist Paul Pastelok said.
The official criteria of a white Christmas, defined by the National Weather Service as at least an inch of snow on the ground on Christmas morning, was not met for many of the lower elevations, due to the timing of the coldest air and snow. The greatest chance of snowflakes flying in Seattle and Portland will continue through Sunday night, with 1-3 inches expected to whiten the cityscapes.
The last time Seattle experienced a white Christmas was in 2017, when 1 inch fell on Christmas Day after 1.6 inches fell the previous day.
In Portland, it's been a much longer wait. It’s been over a decade since the city had Christmas snow, when 0.9 of an inch fell in 2008.
AccuWeather meteorologists say that motorists will have the highest risk of encountering treacherous travel with slippery road conditions through Sunday morning as temperatures dip to near freezing levels.
CLICK HERE FOR THE FREE ACCUWEATHER APP
Travelers over I-90, including Snoqualmie Pass, and other mountain roads across the Washington and Oregon Cascades can expect snow-jammed roadways and extremely difficult driving conditions into the early week, with several feet of snow expected to pile up.
By Sunday, high temperatures are likely to top out in only around 30 F in Seattle and upper 30s in Portland. The average high for both cities at this time of year is 46.
The mercury will plummet further after dark Sunday as the thrust of the icy air charges in. A low of 17 is currently projected in Seattle on Sunday night, which would break the daily record of 20 from 1968. Portland is forecast to challenge its record low of 23 set in 1971.
As precipitation begins to wind down and the sky starts to clear early in the week, temperatures are projected to fall even lower. Seattle and Portland have record lows on Monday night of 12 and 19, respectively, both of which were set in 1990 and could be challenged in the upcoming cold spell.
AccuWeather's long-range team expects colder-than-average weather to linger right through the end of 2021 in the Northwest, setting the stage for a few more opportunities for snow, both in the higher and lower elevations. The unusual chill can add strain on residents' wallets due to increased heating demands.
Farther south along the West coast, rounds of precipitation will continue to pummel California into early this week, with below-average temperatures reaching the Golden State for the final week of 2021.
This active weather pattern in the West is expected to settle down as December shifts to January, according to Pastelok. He added that while there could still be some storms in the West, they will likely not feature as much moisture, which would result in lower rainfall and snowfall amounts.
For the latest weather news check back on AccuWeather.com. Watch the AccuWeather Network on DIRECTV, Frontier, Spectrum, fuboTV, Philo and Verizon Fios. AccuWeather Now is now available on your preferred streaming platform.
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News / Winter Weather
Accumulating snow on the way for Seattle, Portland
A state of emergency has been declared for Oregon residents through January 3rd as a result of the winter weather hazards.
By Renee Duff, AccuWeather senior meteorologist
Published Dec 23, 2021 1:20 PM EDT | Updated Dec 26, 2021 4:04 AM EDT
While the weather in some parts of the United States may have people thinking it's spring, forecasters say residents in the Pacific Northwest will certainly know which season it is into the last week of 2021.
Mother Nature will be providing a late snowy Christmas gift to residents in Seattle and Portland, Oregon, as frigid air rushing into the region will mesh with waves of moisture. Although some Northwest residents may get more than what they bargained for as a state of emergency was declared for Oregon from Christmas Eve through Jan. 3rd due to the expected cold and snow.
The two temperate cities see much more rain than snow most years, with average snowfall totals standing at a mere 4.3 inches for Portland and 6.3 inches in Seattle. But this holiday season, snow won't be exclusively for the region's mountainous areas.
"Bitterly cold Siberian air began to rush southward across British Columbia and Alberta, Canada, at the end of the week, dropping temperatures 15-30 degrees Fahrenheit (8-16 degrees Celsius) below average," AccuWeather Meteorologist Jessica Storm said. "This chill is anticipated to spill over the Canada-U.S. border by early in the coming week, bringing shiver-worthy weather to the Northwest."
"Snow levels can drop close to valley floors, possibly yielding accumulating snow for the I-5 corridor between Seattle and Portland," AccuWeather Lead Long-Range Meteorologist Paul Pastelok said.
The official criteria of a white Christmas, defined by the National Weather Service as at least an inch of snow on the ground on Christmas morning, was not met for many of the lower elevations, due to the timing of the coldest air and snow. The greatest chance of snowflakes flying in Seattle and Portland will continue through Sunday night, with 1-3 inches expected to whiten the cityscapes.
The last time Seattle experienced a white Christmas was in 2017, when 1 inch fell on Christmas Day after 1.6 inches fell the previous day.
In Portland, it's been a much longer wait. It’s been over a decade since the city had Christmas snow, when 0.9 of an inch fell in 2008.
AccuWeather meteorologists say that motorists will have the highest risk of encountering treacherous travel with slippery road conditions through Sunday morning as temperatures dip to near freezing levels.
CLICK HERE FOR THE FREE ACCUWEATHER APP
Travelers over I-90, including Snoqualmie Pass, and other mountain roads across the Washington and Oregon Cascades can expect snow-jammed roadways and extremely difficult driving conditions into the early week, with several feet of snow expected to pile up.
By Sunday, high temperatures are likely to top out in only around 30 F in Seattle and upper 30s in Portland. The average high for both cities at this time of year is 46.
The mercury will plummet further after dark Sunday as the thrust of the icy air charges in. A low of 17 is currently projected in Seattle on Sunday night, which would break the daily record of 20 from 1968. Portland is forecast to challenge its record low of 23 set in 1971.
As precipitation begins to wind down and the sky starts to clear early in the week, temperatures are projected to fall even lower. Seattle and Portland have record lows on Monday night of 12 and 19, respectively, both of which were set in 1990 and could be challenged in the upcoming cold spell.
AccuWeather's long-range team expects colder-than-average weather to linger right through the end of 2021 in the Northwest, setting the stage for a few more opportunities for snow, both in the higher and lower elevations. The unusual chill can add strain on residents' wallets due to increased heating demands.
Farther south along the West coast, rounds of precipitation will continue to pummel California into early this week, with below-average temperatures reaching the Golden State for the final week of 2021.
This active weather pattern in the West is expected to settle down as December shifts to January, according to Pastelok. He added that while there could still be some storms in the West, they will likely not feature as much moisture, which would result in lower rainfall and snowfall amounts.
In other news:
For the latest weather news check back on AccuWeather.com. Watch the AccuWeather Network on DIRECTV, Frontier, Spectrum, fuboTV, Philo and Verizon Fios. AccuWeather Now is now available on your preferred streaming platform.
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