Frequent storms to slam northwestern US beginning this weekend
By
Renee Duff, AccuWeather senior meteorologist
Updated Dec 11, 2020 8:59 PM EDT
A woman was skiing with her husband when she fell down a hidden vent of Mount Hood, an active volcano, in Oregon. The rescued skier speaks out after the terrifying fall.
Forecasters say the increased storminess across the Northwest will put the region "back on track" following a lackluster start to December rain and snowfall.
Up until Tuesday, precipitation was scarce across the region as storm systems were steered to the north into southeastern Alaska and western British Columbia during the first week of December.
A storm on Tuesday brought the most significant rainfall yet this month for places such as Portland, Oregon, and Seattle, with 0.32 and 0.73 of an inch recorded, respectively.
Intermittent rain and mountain snow will linger over parts of the Northwest through Friday before a change in the atmosphere brings heavier precipitation into the area.
"The jet stream over the North Pacific will strengthen, leading to more frequent storms across the Northwest," AccuWeather Lead Long-Range Meteorologist Paul Pastelok said.
When the jet stream is stronger, the storms that this fast-flowing river of air guide along tend to be more intense. This results in more widespread significant precipitation and gusty winds with each storm.
CLICK HERE FOR THE FREE ACCUWEATHER APP
"Beginning this weekend, the period lasting through mid-December will likely start with a bang as a powerful storm appears likely to pound Washington and Oregon with high winds, heavy rain and mountain snow," Pastelok said.
Soaking rain along the Interstate-5 corridor from Seattle to Portland and Medford, Oregon, and perhaps as far south as Redding, California, will lead to a poor weekend to put out last-minute holiday decorations or check out light displays.
A half inch of rain or more is likely in these areas over the weekend, with up to a couple of inches possible along the coast.
Colder air trapped in the lower elevations at the onset of precipitation could lead to a period of freezing rain and slippery travel east of the Cascades.
Across the Cascades, snow levels are likely to rise initially as the storm crashes ashore and milder Pacific air moves in. Just as quickly as temperatures and snow levels come up, however, they will come crashing down as colder air gets dragged in behind the storm.
Travelers over I-90's Snoqualmie Pass should be ready to face road conditions ranging from wet at the onset of precipitation to slushy and snowcovered as the storm progresses.
Beyond the weekend, there may be few discernible breaks between storms as the jet stream remains aimed at the region and moisture continues to stream ashore.
"Up to this point, December has been rather dry, but this increase in storminess will get the region back on track for normal rainfall and snowfall for the month," Pastelok said.
The worst drought across the region is occurring in Oregon, where nearly 70% of the state is experiencing severe to exceptional drought, according to the U.S. Drought Monitor.
The rounds of precipitation past the middle of the month will do well in helping ease these dry conditions, but depending on the intensity and frequency of rainfall, flooding may become a concern. This will be especially true in communities left vulnerable by wildfire burn scars.
At the very least, travel disruptions are likely to mount and opportunities to safely dine and exercise outdoors will dwindle.
AccuWeather will continue to provide details on each storm's impact to the area as they become clearer.
Keep checking back on AccuWeather.com and stay tuned to the AccuWeather Network on DirecTV, Frontier and Verizon Fios.
Report a Typo
News / Winter Weather
Frequent storms to slam northwestern US beginning this weekend
By Renee Duff, AccuWeather senior meteorologist
Updated Dec 11, 2020 8:59 PM EDT
A woman was skiing with her husband when she fell down a hidden vent of Mount Hood, an active volcano, in Oregon. The rescued skier speaks out after the terrifying fall.
Forecasters say the increased storminess across the Northwest will put the region "back on track" following a lackluster start to December rain and snowfall.
Up until Tuesday, precipitation was scarce across the region as storm systems were steered to the north into southeastern Alaska and western British Columbia during the first week of December.
A storm on Tuesday brought the most significant rainfall yet this month for places such as Portland, Oregon, and Seattle, with 0.32 and 0.73 of an inch recorded, respectively.
Intermittent rain and mountain snow will linger over parts of the Northwest through Friday before a change in the atmosphere brings heavier precipitation into the area.
"The jet stream over the North Pacific will strengthen, leading to more frequent storms across the Northwest," AccuWeather Lead Long-Range Meteorologist Paul Pastelok said.
When the jet stream is stronger, the storms that this fast-flowing river of air guide along tend to be more intense. This results in more widespread significant precipitation and gusty winds with each storm.
CLICK HERE FOR THE FREE ACCUWEATHER APP
"Beginning this weekend, the period lasting through mid-December will likely start with a bang as a powerful storm appears likely to pound Washington and Oregon with high winds, heavy rain and mountain snow," Pastelok said.
Soaking rain along the Interstate-5 corridor from Seattle to Portland and Medford, Oregon, and perhaps as far south as Redding, California, will lead to a poor weekend to put out last-minute holiday decorations or check out light displays.
A half inch of rain or more is likely in these areas over the weekend, with up to a couple of inches possible along the coast.
Colder air trapped in the lower elevations at the onset of precipitation could lead to a period of freezing rain and slippery travel east of the Cascades.
Across the Cascades, snow levels are likely to rise initially as the storm crashes ashore and milder Pacific air moves in. Just as quickly as temperatures and snow levels come up, however, they will come crashing down as colder air gets dragged in behind the storm.
Related:
Travelers over I-90's Snoqualmie Pass should be ready to face road conditions ranging from wet at the onset of precipitation to slushy and snowcovered as the storm progresses.
Beyond the weekend, there may be few discernible breaks between storms as the jet stream remains aimed at the region and moisture continues to stream ashore.
"Up to this point, December has been rather dry, but this increase in storminess will get the region back on track for normal rainfall and snowfall for the month," Pastelok said.
The worst drought across the region is occurring in Oregon, where nearly 70% of the state is experiencing severe to exceptional drought, according to the U.S. Drought Monitor.
The rounds of precipitation past the middle of the month will do well in helping ease these dry conditions, but depending on the intensity and frequency of rainfall, flooding may become a concern. This will be especially true in communities left vulnerable by wildfire burn scars.
At the very least, travel disruptions are likely to mount and opportunities to safely dine and exercise outdoors will dwindle.
AccuWeather will continue to provide details on each storm's impact to the area as they become clearer.
Keep checking back on AccuWeather.com and stay tuned to the AccuWeather Network on DirecTV, Frontier and Verizon Fios.
Report a Typo