Biggest snowfall of the winter unfolding for Seattle, Portland
By
Alex Sosnowski, AccuWeather senior meteorologist
Updated Feb 11, 2021 8:58 PM EDT
The first wave in what's shaping up to be the biggest snowfall event of the season for areas of the Interstate 5 corridor began early Thursday and will continue through Thursday night. The snow was the result of a storm from the Pacific that is being followed by a separate storm that will produce heftier snowfall amounts through the weekend.
Light snow was occurring instead of rain in some areas thanks to Arctic air that spilled westward from the Rockies. This is allowing for snow to fall below 500 feet in elevation in some locations, including at Quillayute, Washington, which is located near the Pacific Coast at an elevation of 177 feet. Higher elevations in the coastal areas are likely to pick up greater amounts of snow than locations near sea level in the current setup. In parts of Oregon, including around the Portland metro area, freezing rain was reported early Thursday.
Both Seattle and Portland have dodged much in the way of snowfall so far this winter with only 0.5 of an inch of snow for Seattle and less than 0.1 of an inch for Portland as of Wednesday, Feb. 10. These coastal Northwest cities and others stand a significant chance of picking up a few inches of snow and reaching or exceeding their seasonal average, and possibly significant icing.
The average seasonal snowfall for Seattle is 6.8 inches while 4.3 inches typically falls on Portland.
Higher elevations in the coastal areas are likely to pick up greater amounts of snow than locations near sea level in the setup.
"The spread of just enough Arctic air with the first storm's will lead to snow over a large part of of the Northwest, including a significant part of the Interstate 5 corridor in Washington and Oregon," AccuWeather Meteorologist Adam Sadvary said.
At this time, AccuWeather meteorologists are projecting the Seattle area to receive an average of 1-3 inches of snow with coastal areas farther south toward Olympia, Washington, standing a better chance for 6 inches or more from the first storm.
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“There is a chance that sleet and freezing rain mix in at the height of the first storm in Portland, but if that does not happen or the mixing is limited, then a 3- to 6-inch snowfall amount could easily be reached from the first storm,” AccuWeather Senior Meteorologist Bob Smerbeck said.
AccuWeather is projecting 1-3 inches of snow to fall on Portland from the first storm with sleet and freezing rain forecast to hold back accumulations in the city.
"There is the likelihood for a foot of snow to fall on the Cascades of southern Washington and northern Oregon into Friday, with more on the way this weekend," Sadvary said.
"Snowfall amounts of this magnitude can enhance the risk for avalanches, which have already been occurring at a high frequency over the West in general this season," Sadvary said.
Rain along with high country snow is forecast farther south in Oregon and Northern California into Friday. Enough rain may fall along the coast of southern Oregon and Northern California to lead to isolated flash flooding and mudslides.
A combination of rain and wet snow is forecast for Donner Pass, California, along I-80.
Rain showers may make it as far to the south as the Los Angeles area by Friday. While even spotty showers can be a nuisance for motorists, enough rain is not expected to fall to raise the risk of mudslides in Southern California.
After Friday, even more wintry weather is on the way, and this second storm could be even more robust than the first in terms of both snow and ice.
"With more arctic air set to drain in from the northeast, snow is likely to be more widespread and perhaps heavier Friday night through Sunday than during the first storm from Bellingham to Seattle and Portland, AccuWeather Meteorologist Matt Benz said.
With little time and a lack of warmth between the first and second storm, it is unlikely that much of the snow from the first storm will have the opportunity to melt, making for some substantial snow totals by the end of the weekend.
By the time the second storm pushes inland Saturday night, some areas near or just above sea level on the Washington and northern Oregon coasts may have double-digit accumulations of snow on the ground.
"Seattle is forecast to 6 to as much as 10 inches of snow by the end of both storms, which could surpass the city's average annual snowfall of 6.8 inches," said AccuWeather Senior Meteorologist Courtney Travis.
The Washington and northern Oregon Cascades may be buried under 2-3 feet of new snow since the middle of this week.
Another round of icing is expected for southwestern Washington and northwestern Oregon, which could include cities like Portland and Salem Oregon, and even southward to Eugene.
Between the ice of both storms, there could be an area of significant ice accumulation, near and possibly exceeding 0.50. In this zone of most severe icing, travel is expected to be very dangerous.
Gusty winds will accompany both storms and the Arctic air pouring in through the weekend. The wind will create blowing and drifting snow and poor visibility at times. Forecasters say it can also lead to blizzard conditions over the passes and high country in the Cascades.
Gusty winds will also result in AccuWeather RealFeel® Temperatures being 10-20 degrees Fahrenheit lower than the actual temperature at times. Seattle, for example, can expect RealFeel® Temperatures in the teens to lower 20s through the weekend.
Temperatures are forecast to rebound some in the Pacific Northwest early next week with afternoon high temperatures in the lower to middle 40s.
Keep checking back on AccuWeather.com and stay tuned to the AccuWeather Network on DirecTV, Frontier and Verizon Fios.
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News / Winter Weather
Biggest snowfall of the winter unfolding for Seattle, Portland
By Alex Sosnowski, AccuWeather senior meteorologist
Updated Feb 11, 2021 8:58 PM EDT
The first wave in what's shaping up to be the biggest snowfall event of the season for areas of the Interstate 5 corridor began early Thursday and will continue through Thursday night. The snow was the result of a storm from the Pacific that is being followed by a separate storm that will produce heftier snowfall amounts through the weekend.
Light snow was occurring instead of rain in some areas thanks to Arctic air that spilled westward from the Rockies. This is allowing for snow to fall below 500 feet in elevation in some locations, including at Quillayute, Washington, which is located near the Pacific Coast at an elevation of 177 feet. Higher elevations in the coastal areas are likely to pick up greater amounts of snow than locations near sea level in the current setup. In parts of Oregon, including around the Portland metro area, freezing rain was reported early Thursday.
Both Seattle and Portland have dodged much in the way of snowfall so far this winter with only 0.5 of an inch of snow for Seattle and less than 0.1 of an inch for Portland as of Wednesday, Feb. 10. These coastal Northwest cities and others stand a significant chance of picking up a few inches of snow and reaching or exceeding their seasonal average, and possibly significant icing.
The average seasonal snowfall for Seattle is 6.8 inches while 4.3 inches typically falls on Portland.
Higher elevations in the coastal areas are likely to pick up greater amounts of snow than locations near sea level in the setup.
"The spread of just enough Arctic air with the first storm's will lead to snow over a large part of of the Northwest, including a significant part of the Interstate 5 corridor in Washington and Oregon," AccuWeather Meteorologist Adam Sadvary said.
At this time, AccuWeather meteorologists are projecting the Seattle area to receive an average of 1-3 inches of snow with coastal areas farther south toward Olympia, Washington, standing a better chance for 6 inches or more from the first storm.
CLICK HERE FOR THE FREE ACCUWEATHER APP
“There is a chance that sleet and freezing rain mix in at the height of the first storm in Portland, but if that does not happen or the mixing is limited, then a 3- to 6-inch snowfall amount could easily be reached from the first storm,” AccuWeather Senior Meteorologist Bob Smerbeck said.
AccuWeather is projecting 1-3 inches of snow to fall on Portland from the first storm with sleet and freezing rain forecast to hold back accumulations in the city.
"There is the likelihood for a foot of snow to fall on the Cascades of southern Washington and northern Oregon into Friday, with more on the way this weekend," Sadvary said.
"Snowfall amounts of this magnitude can enhance the risk for avalanches, which have already been occurring at a high frequency over the West in general this season," Sadvary said.
Rain along with high country snow is forecast farther south in Oregon and Northern California into Friday. Enough rain may fall along the coast of southern Oregon and Northern California to lead to isolated flash flooding and mudslides.
A combination of rain and wet snow is forecast for Donner Pass, California, along I-80.
Rain showers may make it as far to the south as the Los Angeles area by Friday. While even spotty showers can be a nuisance for motorists, enough rain is not expected to fall to raise the risk of mudslides in Southern California.
Related:
After Friday, even more wintry weather is on the way, and this second storm could be even more robust than the first in terms of both snow and ice.
"With more arctic air set to drain in from the northeast, snow is likely to be more widespread and perhaps heavier Friday night through Sunday than during the first storm from Bellingham to Seattle and Portland, AccuWeather Meteorologist Matt Benz said.
With little time and a lack of warmth between the first and second storm, it is unlikely that much of the snow from the first storm will have the opportunity to melt, making for some substantial snow totals by the end of the weekend.
By the time the second storm pushes inland Saturday night, some areas near or just above sea level on the Washington and northern Oregon coasts may have double-digit accumulations of snow on the ground.
"Seattle is forecast to 6 to as much as 10 inches of snow by the end of both storms, which could surpass the city's average annual snowfall of 6.8 inches," said AccuWeather Senior Meteorologist Courtney Travis.
The Washington and northern Oregon Cascades may be buried under 2-3 feet of new snow since the middle of this week.
Another round of icing is expected for southwestern Washington and northwestern Oregon, which could include cities like Portland and Salem Oregon, and even southward to Eugene.
Between the ice of both storms, there could be an area of significant ice accumulation, near and possibly exceeding 0.50. In this zone of most severe icing, travel is expected to be very dangerous.
Gusty winds will accompany both storms and the Arctic air pouring in through the weekend. The wind will create blowing and drifting snow and poor visibility at times. Forecasters say it can also lead to blizzard conditions over the passes and high country in the Cascades.
Gusty winds will also result in AccuWeather RealFeel® Temperatures being 10-20 degrees Fahrenheit lower than the actual temperature at times. Seattle, for example, can expect RealFeel® Temperatures in the teens to lower 20s through the weekend.
Temperatures are forecast to rebound some in the Pacific Northwest early next week with afternoon high temperatures in the lower to middle 40s.
Keep checking back on AccuWeather.com and stay tuned to the AccuWeather Network on DirecTV, Frontier and Verizon Fios.
Report a Typo