Atmospheric River Notice Issued for West Coast, Heavy Snow, Rain, and High Winds Possible
Across the West Coast, the coming days look wet, with the Climate Prediction Center warning of atmospheric river activity potentially bringing heavy rain, snow, strong winds, and flooding.
The notice, updated on November 3, pegs the odds of heavy precipitation hitting western Washington, Oregon, and parts of California at “moderate” (between 40% and 60%) starting on November 11, 2026.
The “moderate” risk of heavy snow is less widespread but still applies to the higher elevations of the Klamath and Sierra Nevada mountain ranges between November 11 and November 15.
A “slight risk” of heavy snow (20% to 40%) extends to November 17 for high elevations of the Cascades, Klamath, and Sierra Nevada, as well as the Northern Intermountain, Great Basin, and Central and Northern Rockies.
“Monitor local forecasts for safety alerts, avoid driving through flooded roadways, and use caution if traveling through high elevations,” the CPC advised. “Be prepared for power outages due to high winds.”
NOAA/CPC
There is potential for significant, multi-foot snow totals during the cycle.
Chris Tomer, a meteorologist who shares detailed snow updates during the winter on YouTube, offered some prospective mid-mountain snow totals by the end of November 13, accounting for the wet period.
British Columbia is slated to be the biggest winner in his forecast, with more than three feet of snow falling on Whistler Blackcomb. But along the West Coast, from Crystal Mountain, Washington, to Mammoth Mountain, California, Tomer called for between 1 and 2 feet of snow. At Whistler, the highest peaks might even see over 100 inches.
But temperatures remain an unanswered question, depending on elevation.
“Details on snow levels and precipitation totals are foggy at this point, but I think it’s safe to say we could be looking at a very wet couple of days next week,” Clinton Alden, a meteorologist for OpenSnow, wrote in a recent Washington forecast.
Tomer also pointed to the rain-snow line in his latest video. He called that aspect of the system “critical,” with “potentially rain at a lot of base areas but heavy snow somewhere between mid-mountain and the top, the very top of these ski areas.”
“On the highest peaks we’re gonna be looking at some big time snow accumulations,” he said, adding that he thinks the 100-inch setup is “still very much in the cards.”
The prospective wet and wild period arrives as more and more ski resorts begin thinking about opening dates. On the West Coast, the current frontrunners are Mt. Rose, Nevada, and Mammoth Mountain, California, which plan to open this week on November 6 and November 5, respectively.
Heavy snow, even if it only arrives at the mid-mountain, could help other ski resorts build their base ahead of their opening dates.
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