Atmospheric river timeline as multiple storms take aim at US
What’s New
“Yet another” atmospheric river is unleashing stormy weather across the Pacific Northwest on Tuesday, with two more similar storms set to hit this coming weekend, a National Weather Service (NWS) Weather Prediction Center forecast said.
Why It Matters
The Pacific Northwest is known for its atmospheric rivers, particularly during the winter months. They bring a deluge of rain and heavy snow to California, Oregon and Washington. Though the moisture-laden storms can help alleviate drought, they also pose life-threatening risks with mudslides and floods.
Multiple storms have already hit the West Coast this month, with more on the way, meteorologists predict.
With this holiday season expected to be one of the busiest for travelers, the stormy weather could cause challenges for those with Christmas travel plans.
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What to Know
Atmospheric rivers are a “long, narrow region in the atmosphere—like rivers in the sky—that transport most of the water vapor outside of the tropics,” according to the National Oceanic and Atmospheric Administration.
According to the NWS forecast, the current storm will take a northerly track that will bring the heaviest rainfall to the coastal ranges of northern Oregon and Washington with up to 6 inches. Heavy mountain snow is expected in the northern Cascade Mountains.
Some locations in the Pacific Northwest are already seeing moisture from the first atmospheric river that will impact the region on Tuesday, though the storm won’t be intense. The next storm will clip far northwest Washington on Thursday night, with the third atmospheric river hitting the West Coast from the San Francisco Bay area northward through Washington on Sunday night into Monday. None of the atmospheric rivers are expected to be particularly strong.
Winter storm warnings and winter weather advisories issued by NWS offices in the impacted areas are concentrated in north central Oregon and across much of Washington. Some winter weather advisories extend into Idaho and Montana as the storm continues its trek into the U.S.
Parts of California, Oregon and Washington are among the states that have the highest chance at a white Christmas this year, according to an AccuWeather forecast, in part due to the heavy snow hitting the area from the atmospheric rivers.
What People Are Saying
NWS Weather Prediction Center in a forecast: “Yet another Pacific system will help to usher in a wave of Pacific moisture/Atmospheric River into the Pacific Northwest and inland over the northern Great Basin/Rockies Tuesday.”
NWS Weather Prediction Center meteorologist Brian Hurley told Newsweek: “The first atmospheric river isn’t impacting major metropolitan areas outside of some moderate rain. Once that moves out, we are then looking at the next potential starting Thursday or Friday, though it doesn’t look like it will affect anybody outside of northwest Washington.”
AccuWeather long-range expert Paul Pastelok previously told Newsweek: “Back-to-back” storms continue to hammer the West Coast, with one likely to unleash an atmospheric river early next week.
What’s Next
The West Coast is expecting a break in the storms in the middle of the week this week, but at least two more storms are lining up to hit the West Coast over the weekend and early next week, with a wet weather pattern expected for the Pacific Northwest up until Christmas.
Weather patterns also are hinting at another atmospheric river that could hit on Christmas Day, although there’s uncertainty with the storm’s timing and strength.
