Moisture Making a Return to the Pacific Northwest to Start the Week

Posted: April 3, 2022 10:24 am

After a relatively dry end to the month of March, a new round of wet weather is set to kick off April with a soggy start in the Pacific Northwest.

Moisture to Dive Down from Canada Late Sunday

Most areas of this corner of the country wrapped up the month with precipitation levels below normal, including major cities such as Seattle, Portland, and Boise. This will make this new influx of moisture a significant change for those who may have become accustomed to the dry conditions.

The system is currently positioned over British Columbia, Canada. The storm is forecast to move to the southeast through the southern tier of Alberta and into Washington state, Idaho, Montana, Oregon, and northern California beginning late Sunday. This weather maker will eventually make its way into the Midwest and the Great Lakes by the middle of the week as it tracks to the east over the next several days.

What to Expect Out of the Precipitation

The mass of moisture is expected to manifest itself as rain in the lower elevations, with snow falling in the higher terrains. Rainfall amounts measuring up to two inches are forecast for the inland section of southern British Columbia, Washington, and Oregon. This persistent rain will continue through Tuesday, raising concerns of flooding for rivers and urban waterways.

The coastal areas in this region will face an even higher flood risk as rainfall totals could potentially approach four inches over a 48-hour time period. The cities of Seattle and Portland should expect rain showers that bring 1 – 2 inches of rain.

Despite the dry conditions of the last few weeks, it has been a wet start to the year for Seattle. The Emerald City measured 114% of its normal rainfall for the first three months of 2022. Heading into April, Seattle measures an average of 3.18 inches of rain. Farther to the south in Portland, residents typically see 2.89 inches of rain for the month. This upcoming storm system could deliver a significant head start on hitting these April averages with up to one-third of the total monthly amount possible.

What to Expect with the Snow

In the higher elevations, it will be snow that may complicate the weather landscape. In addition to snow, gusty winds may whip throughout the Cascade Mountains in Washington and Oregon starting Sunday and continuing through late Tuesday.

Snow levels may drop to 3,000 feet on Sunday, causing a slew of travel issues over the mountain passes. By Monday morning, snowfall accumulations may hit 3 to 6 inches throughout the Cascades with the heaviest snow falling early Monday through Tuesday morning. During this time, the snow levels may drop to 2,000 feet. Up to two feet of snow may fall in the highest elevations of this region.

The roadways most likely to be impacted by snow and blustery winds include Interstate 90 and Routes 2 and 12, including the heavily traveled Snoqualmie and Stevens passes in Washington.

Winds to Whip Up

This massive system will also bring the concern of damaging winds, even at the lower elevations. Gusts of 40 – 50 mph will be a possibility starting early Monday throughout Washington and Oregon. The winds will begin to move into the northern Rocky Mountains by late Monday.

These winds will bring the threat of blowing snow or dust. The gusts may also present dangers for high-profile vehicles.

This system is forecast to exit the region by Wednesday as it continues its journey to the east. A brief period of dry weather will settle into the Pacific Northwest for a few days to end the week before more moisture arrives in time for the weekend.