By AccuWeather meteorologist
Updated Nov. 16, 2020 12:50 PM
After two quick-hitting systems back-to-back to end the week, rounds of unsettled weather will continue to affect the Northwest through at least midweek.
The first storm system to impact the northwestern United States brought heavy rain and mountain snow to the region into the early weekend, while the second system arrived shortly after the first departed.
The second system tracked east over the eastern Pacific Ocean and pushed into southern British Columbia, Canada, late Saturday afternoon. Periods of rain began across the coastal Pacific Northwest as a warm front associated with this system nosed into the area.
By Saturday evening, a potent cold front swept in right behind this warm front and brought a threat for heavy rain to lower elevations and heavy snow to higher elevations across the Northwest and the northern Rockies that lasted through Sunday.
As was the pattern over the weekend, many locations will not have adequate time to dry out before yet another system approaches the Northwestern states on Monday.
Moisture will stream into the Pacific Northwest on Monday as a powerful storm system churns a few hundred miles off the coast of Washington. Early Monday, a warm front associated with this system will stretch from the the Washington-Oregon border coastline to the northern Rockies. Rain and higher-elevation snow will develop on Monday as this warm front slowly pushes north across the Canadian border.
Generally, the heaviest rain that falls on Monday will be confined to the western portions of Washington and Oregon, as well as southern British Columbia, Canada. Locations like Seattle and Victoria, B.C., Canada, can experience periods of drenching rain Monday afternoon.
CLICK HERE FOR THE FREE ACCUWEATHER APP
While late fall into early winter is typically the wettest time of the year for the region, heavy rain is still likely to cause quite a few issues for the Northwestern states. With the soil already saturated in many locations, flash flooding will likely be a threat where the heaviest rain falls on Monday.
In addition to rain, snow will likely fall across the highest elevations of the Washington Cascades and portions of the northern Rockies.
This same storm system will push closer to the coast on Tuesday and trigger yet another soggy day for many.
Portions of the Northwestern states will likely experience a brief break between rounds of precipitation during Tuesday morning before a cold front approaches the area. Tuesday afternoon, a cold front associated with the same storm system will stretch from western Oregon to central California and push eastward throughout the day.
This cold front will trigger rounds of rain and high-elevation snow from Tuesday afternoon through Tuesday night for much of the Northwest and northern Rockies. Even Northern and central California will get in on the action on Tuesday with rain expected in San Francisco and showers forecast to reach as far south as Cambria, California.
RELATED:
Winds will also kick up significantly on Tuesday as the center of the storm system strengthens and approaches southwestern British Columbia. The strongest winds from this system will occur at the coast and in the higher elevations from California and Nevada to Montana.
At the coast as well as in some mountain locations, wind gusts of 50-60 mph are likely from Northern California to northwestern Washington. Wind gusts of this magnitude can contribute to coastal flooding, especially around high tide, as well as lead to downed trees and power lines. A few localized wind gusts of 70-80 mph are possible in the areas. Even interior portions of Oregon will also see wind gusts of 35-45 mph as well.
Moisture from this system will persist across the northwestern U.S. through at least Wednesday. On Wednesday, another cold front will push from the Pacific coast through the Pacific Northwest. This front will interact with the leftover moisture from the early week storm system and prompt another soggy day for the Northwest, especially at the coast.
This week will really start to sound like a broken record weather-wise on Wednesday as showers target the lower elevations and snow once again targets the higher elevations. Unlike earlier in the week, accumulating snowfall will be able to reach much farther south.
Snow levels will fall to around 6,000 to 7,000 feet across the central Sierra and as low as 5,000 feet in the northern Sierra. Above these levels, which include Donner Pass, 6-12 inches of snow can fall.
"Travel could get tricky along Interstate 80 up and over the Sierras Tuesday night and Wednesday." said AccuWeather Meteorologist Jake Sojda. "The snow will also be combined with gusty winds in the Sierras, leading to even worse visibility along with the already slippery roads and falling snow."
Localized snowfall of 1-2 feet will also be possible where the heaviest snow falls in the Sierra. Ski resorts will enjoy the fresh powder as they look forward to getting the season started.
More snow will also bury parts of the Cascades again Tuesday night into Thursday. Snow levels will generally fall to around 2,000 to 3,000 feet by Wednesday in the Cascades. Over the 2 day period, many places in the mountains will see at least and additional foot or more of fresh snow. Travelers through passes like Stevens and Snoqualmie will once again have to be prepared for hazardous winter weather.
While much of the first half of the week will be dreary and soggy for many, any rain and snow that falls will be beneficial for much of the Northwest and portions of California, especially where significant drought remains in place. Much of Oregon and Northern California are still in the midst of severe to extreme drought, according to the United States Drought Monitor, but days of unsettled weather are a step in the right direction.
Late in the week, a more extended reprieve from the rain and snow finally looks to be in the offing for the Northwest.
Keep checking back on AccuWeather.com and stay tuned to the AccuWeather Network on DirecTV, Frontier and Verizon Fios.
No comments:
Post a Comment