Winter returns: Rain, mountain snow, and blustery conditions ahead in Western Washington

Better late than never! More typical winter-like weather is in store this week, with lowland rain and mountain snow, along with blustery conditions and even the threat of a thunderstorm.

A strong airflow aloft, called the jet stream, at roughly 30,000 feet, will be funneling cold, unstable air from the Gulf of Alaska region into Western Washington through this week. This weather pattern will generate showers in the lowlands, with rain totals ranging from a half-inch to more than 2 inches, and plenty of snow in the mountains.

Low Snow Levels

Snow levels are expected to vary from as low as 500 feet on Monday and Tuesday to as high as about 3,000 feet on Wednesday, before dropping to around 2,000 feet for the rest of the week. The lower snow levels early this week will likely result in a mix of rain and snow in some Western Washington lowland areas during overnights and morning hours. Some locations may receive light snow accumulations on grassy surfaces and rooftops.

Piling Up Mountain Snow – Rising Avalanche Conditions

The real snow accumulations will be in the mountains. During the week, upwards of 2 to 4 feet of snow is expected. Drivers going over the mountain pass highways should anticipate hazardous winter driving conditions.

Per state law, always carry chains and be prepared to use them if directed. Otherwise, ensure your vehicle has winter weather resources, such as extra food, water, a snow shovel, traction sources like kitty litter or sand, and flashlights with extra batteries. Be prepared in case highway crews need to hold traffic for avalanche control.

This late winter surge in mountain snow will also create rising avalanche conditions. Monitor the Northwest Weather and Avalanche Center for the latest forecasts and conditions before heading into the backcountry.

More Mountain Snow Needed

Earlier this month, the Northwest Weather and Avalanche Center reported snow depths in the Olympics and Cascades were averaging only about 35 to 65 percent of normal. This week’s mountain snows will help cut into this deficit, yet even more is needed to approach average. April 1 is usually when the mountain snowpack reaches its peak for the season.

The new snow is welcome news for ski areas and snow enthusiasts who have had a tough winter so far—this fresh snow has been long-awaited.

This surge in mountain snows will also help with the region’s water supply heading into summer and early fall, particularly for agriculture, power generation, recreation, fish, and drinking water.

The need for more mountain snow is at a critical point. According to the Natural Resources Conservation Service, the amount of water in the snowpack this past weekend was only about 35 to 45 percent of average, with the exception of the North Cascades, which were close to 75 percent of average.

Cooler Temperatures Than Average This Week and Blustery

In the lowlands, temperatures this week will be cooler than mid-March averages, which are in the lower 50s for highs. Low temperatures are expected to range from the lower 30s to mid-40s throughout the week.

This active weather pattern is also expected to generate blustery conditions at times. The strongest winds are expected along the coast and in the north interior, from about Whidbey Island northward, peaking on Wednesday with gusts up to 50 mph. Isolated power outages are possible.

This cooler, more winter-like weather pattern is expected to extend into the coming weekend. Beyond that, the latest 8- to 14-day outlook shows good odds of above-average temperatures and precipitation.

March is feeling like a lion. Will it go out like a lamb, as the phrase dating back to the early 18th century goes? The latest weather outlook for the rest of the month shows odds tipping toward warmer-than-average temperatures and around-average precipitation—so perhaps the month will finish more like a lamb.