A blizzard warning took effect this evening across the Cascade Mountains and the Olympic Peninsula as a powerful storm system brought whiteout conditions to mountain passes and threatening wind gusts to lowland communities across Western Washington.
The National Weather Service issued the warning for Stevens Pass, Snoqualmie Pass, and the Olympics, covering a period from 6 p.m. Today through 5 a.m. Thursday. Forecasters warned that heavy snow combined with wind gusts of 40 to 60 mph would reduce visibility on roadways to below a quarter mile. The criteria for a blizzard warning require large amounts of snow, winds exceeding 35 mph, and visibility under a quarter mile sustained for at least three hours. NWS Seattle has issued just seven blizzard warnings total, four of them in the last two years.
Mountain travel became dangerous or impossible due to Blizzard
Conditions in the Cascades deteriorated quickly this afternoon. Around 11 inches of snow had already fallen at the Summit at Snoqualmie in the 24 hours leading up to the storm’s main push, and forecasters expected an additional 1 to 3 feet of snow across much of the range through Friday.
Washington State Department of Transportation said conditions at Snoqualmie Pass on Interstate 90, Stevens Pass on Highway 2, White Pass on Highway 12, and other mountain routes were expected to worsen significantly through Wednesday night. WSDOT said it would redirect snow plows from other regions to assist with the mountain passes if forced closures became necessary. Drivers who could not avoid mountain travel were urged to allow substantial extra time and prepare for severe winter conditions.
Meteorologists warned that any brief improvement at Snoqualmie Pass during the afternoon, when a temporary rise in snow levels could briefly change conditions to rain, was not a reliable travel window. The heavy snow and wind were expected to return within hours.
Lowlands faced a damaging evening commute
For communities in the Puget Sound lowlands, the primary threat Wednesday was wind. A wind advisory went into effect at 3 p.m. and extended through 6 a.m. Thursday, covering much of western Washington. Forecasters said the storm center was tracking toward Vancouver Island during the afternoon, pulling south winds up through the region.
Peak gusts in the lowlands were expected between 5 and 8 p.m., with gusts of 45 to 50 mph forecast for Seattle, Tacoma, and surrounding areas. Coastal zones and areas near the water faced gusts up to 55 mph. A second wind surge was expected between 8 and 11 p.m. driven by west winds through the Strait of Juan de Fuca, with Whidbey Island, Camano Island, the San Juan Islands, and parts of Snohomish, Skagit, and northern King counties at risk for gusts of 50 mph or more out of the west and northwest.
Forecasters said the west wind direction was less common than south winds and could affect trees in unexpected ways, raising the risk of downed limbs and power outages. Heavy rain accompanying the wind was expected to make driving conditions miserable through the evening, with standing water on roads and reduced visibility adding to commute hazards.
What comes after the weekend for blizzard update
Snow in the mountains was expected to continue through Thursday and Friday before a brief break this weekend. Saturday into Sunday offered the best window for mountain travel and ski conditions before the next system arrived.
The larger concern was a warm atmospheric river forecast to arrive early next week, with snow levels rising to 6,000 to 8,000 feet between Sunday and Tuesday. Forecasters described the incoming system as similar in character to warm, Hawaii-originating storms that struck the region in November and December, bringing heavy rain on top of fresh mountain snowpack and raising concerns about localized flooding in lower elevation areas.
Residents in Western Washington were advised to charge devices, prepare for potential power outages, and avoid mountain travel through at least Thursday morning.
