It was a dark and stormy night indeed – literally! Tuesday night’s storm was the latest soggy storm this month and ‘blew’ through the North Sound overnight as it headed further inland.
This storm produced strong wind gusts in the North Sound, peaking between 35 and 50 mph. Normally, these kinds of winds would not do too much damage. Yet with the saturated soils, it was much easier to blow down trees and take power lines with them, knocking power out for over 400,000 customers in Western Washington including nearly 100,000 Snohomish County PUD customers.
Trees and power lines fell onto many roads including southbound I-5 just south of SR 531 in Arlington, SR 9 in Lake Stevens, and SR 9 just north of SR 522 in Woodinville. All the debris was cleared and the roadways were open again by mid-morning on Wednesday. In addition, the strong wind blew a semi-truck over onto the Deception Pass Bridge guard rail. The truck was righted and moved off the bridge, opening the highway again around sunrise Wednesday.
This storm was associated with a moist atmospheric river – aka – pineapple express – that started on Monday, producing several days of significant rain amounts. The system’s associated cold front moved through the North Sound overnight Tuesday, producing the strong winds.
This storm generated a lot of rain, punctuating our wettest early January on record. From Monday into Wednesday morning, the Cascade foothills received between 3 and 7 inches of rain while the lowlands got 1 to 3 inches of rainfall. For the month so far, many locations have gotten between 6 and 15 inches of rain. Snow levels rose to 6000 feet Monday. Fortunately, the mountain snowpack soaked up much of the rain like a sponge, but lower elevation snow did contribute to runoff into rivers and streams.
Many North Sound rivers rose above flood stage Tuesday night into Wednesday. With the passage of the cold front, snow levels dropped well below the passes Wednesday morning, cutting off both the rain and runoff, and permited rivers to recede rather quickly.
Soils are soaked and the landslide risk will remain high through at least the weekend. Sounder train service between Everett and Seattle has been suspended the rest of this week thanks to the landslide threat along the route. Replacement bus service will continue until the rail service resumes. Other areas with steep slopes remain at risk for landslides throughout the North Sound.
Take note of these continued risks. If you live on a hillside, be on alert for landslides. If you live in a flood prone area, be prepared with sand bags or evacuation routes if necessary.
Fortunately, this period of wet, mild and windy weather has run its course. Cooler drier weather is in store next week. Thursday looks like a more than welcome dry day with sunshine. A couple of weak weather systems may produce a little light rain Thursday night into Friday morning, and again late in the weekend, yet nowhere near as much rain as has fallen so far this month.
The overall weather pattern is expected to change next week. Much cooler weather with showers at times is expected to develop with snow levels perhaps falling as low as the foothills before the end of the week. This weather pattern will be a welcome break from the incessant rain thus far this month.