Atmospheric Rivers Will Soak The West Coast This Week, Including Flood-Weary Washington State
- - Atmospheric Rivers Will Soak The West Coast This Week, Including Flood-Weary Washington State
Jonathan Belles December 15, 2025 at 6:00 AM
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The Pacific Northwest has had a couple of days to dry out after days of flooding rainfall, but there is another atmospheric river washing ashore early this week, and that's just one of a series that will strike the West Coast, including Oregon and California into next weekend.
The map below shows the first of these atmospheric rivers pushing into the Northwest.
(MORE: What Is An Atmospheric River?)
Warmer colors indicate deeper moisture content in the atmosphere.Timing Through This Week
Monday: Heavy rain for western Washington and northwest Oregon.
Tuesday: A brief break in the rain early in the day, then rain and strong winds arrive from a cold front later in the evening and overnight across Washington, Oregon and northwestern California.
Wednesday: Heavy snow and strong winds in the Cascades. Lighter showers continue in lower elevations of western Washington and northwest Oregon.
Thursday: Another atmospheric river arrives, but the heaviest rain will be focused in Oregon.
Friday: The atmospheric river shifts into Northern California. The impacts will remain mainly north of the Bay Area, with showers and mountain snow.
Data: CW3EImpacts
It won’t take as much rainfall to create significant issues, especially in Washington, given the amount of rain they have received last week.
With the first atmospheric river moving onshore, the lowlands could see around an inch of rain, 1 to 2 inches along the coast, and 2 to 3 inches in the mountains. Some isolated locations could see as much as 4 inches. This will cause rivers and streams to rise once again.
Winds could gust as high as 55 mph through Tuesday evening as well, increasing the likelihood of power outages.
As more rain pushes onshore by mid-week, heavy snow will also impact the Cascades Tuesday night through Wednesday.
One to three feet of snow will be possible in the mountains, with several passes also picking up several feet of snow.
For Northern California, rainfall totals should largely be less than 2 inches across much of the region, however, travel will remain treacherous due to slick roads. More impacts will be felt with the system moving onshore later in the week, with significant rain and mountain snow possible.
Areas receiving snow are depicted in white.More Atmospheric Rivers Later This Week, Month?
Most people in the Pacific Northwest, and probably people around the country who know people who live in the Pacific Northwest, are likely wondering if a more long-term dryness is in the forecast.
I hate to be the bearer of bad news, but we may have more atmospheric rivers on the way. After several rounds of rain this week, expect more as we head into the last few weeks of December.
The atmospheric conditions, including a mid-level ridge over the Bering Sea and a downstream trough in the northeastern Pacific, will serve as a a sort of an atmospheric nozzle that will likely steer additional moisture to the already waterlogged West Coast.
I guess a slight silver lining here is that most models are suggesting that the heaviest rain is expected across Oregon and California, however, should any new rainfall hit Washington, it could easily cause flooding due to saturated soils.
Another slight sign of good news is that temperatures may not be as warm in the coming weeks across the West as they are currently, which means snowfall is more likely across the Cascades and Sierra Nevada.
Note that snowmelt across the Cascades exacerbated the flooding from the heavy rainfall across the Pacific Northwest, so more of the precipitation across the mountains falling as snow will help to reduce some river flooding and can also help rebuild snow for skiiers and snowboarders planning to hit the slopes to end 2025.
Jonathan Belles has been a digital meteorologist for weather.com for 9 years. His favorite weather is tropical weather, but also enjoys covering high-impact weather and news stories and winter storms. He's a two-time graduate of Florida State University and a proud graduate of St. Petersburg College.
Source: “AOL Breaking”
