Snow in mountain passes could disrupt travel this week

The Cascades and western Washington are expected to get a significant amount of snow Tuesday and Wednesday, to the point that the National Weather Service (NWS) has issued a Winter Storm Warning.

According to meteorologists with the NWS, rain, and snow will start up around the Puget Sound region early Tuesday morning as a front comes in from the Pacific alongside strong winds gusting from 30-40 mph. Widespread rain will pour in the lowlands around Seattle and Tacoma, and the rain/snow mix at the mountain passes will change to heavy snow Tuesday afternoon.

Mountain snowpack has fallen behind; could impact water supply

This comes in time to make up the winter snowpack that has been lagging behind normal levels for this time of year, according to KIRO Newsradio meteorologist Ted Buehner.

“Last winter, we also had a milder and drier period from mid-January to mid-February resulting in the mountain snowpack ranging from 65% to 95% of the standard average for the middle of February. As of Feb. 1 this year, the latest snow depth statistics from the Northwest Avalanche Center showed that the Cascade and Olympic Mountain snowpack ranged from 58% to 93% of normal,” Buehner said.

The National Weather Service (NWS) issued a Winter Storm Warning from early Tuesday through Wednesday morning for the Cascades of Whatcom and Skagit counties, including the Mount Baker Ski Area. Heavy snow is expected above 3,000 feet, and total accumulations of 12 to 24 inches are possible, according to the NWS.

“Snow-covered roads and travel delays possible across the Cascade passes. Expect difficult travel conditions at times. Temporary pass closures are possible due to incidents. Gusty winds may cause localized power outages and tree limb damage. Temporary structures could be damaged,” the NWS warn in their advisory.

A Winter Weather Advisory will also be in effect for the same time period for Stevens and Snoqualmie passes. The most significant accumulations are expected to be at elevations above 3,500 feet, with around 14-18 inches possible at Stevens Pass, and 7 to 11 inches at Snoqualmie Pass, the NWS said.

Snow is expected across the mountain passes over the next couple of days. For Snoqualmie Pass in particular, snow will likely begin to accumulate quickly Tuesday afternoon through Wednesday morning and may result in difficult travel conditions at times. #wawx pic.twitter.com/JhgiJYzNkM

— NWS Seattle (@NWSSeattle) February 6, 2023

River flooding may lead to minor inundation of flood-prone areas such as farmland and low-lying roadways.

The Washington State Department of Transportation (WSDOT) warns that drivers should be cautious as travel over the passes could be especially slick and dangerous, and traffic could be heavier than normal due to the road conditions. Drivers should plan ahead, and check conditions before traveling through the mountains this week, WSDOT said.

As we move into the weekend, the rain and snow will peter out, leaving only lingering showers and some sunny skies Saturday, with a possibility of mountain snow again early next week.