Sounder commuter trains connecting Snohomish County to Seattle will be canceled all week because of continued rain in the weather forecast that raises the threat of landslides.

A so-called atmospheric river has brought more than the usual January dose of precipitation.

So far this month, 9.4 inches have fallen in the Snohomish River basin, or 87% more than normal. The National Weather Service predicted a 90% chance of rain Tuesday evening, and more showers Thursday evening.

Traffic Lab is a Seattle Times project that digs into the region’s thorny transportation issues, spotlights promising approaches to easing gridlock, and helps readers find the best ways to get around. It is funded with the help of community sponsors Alaska Airlines, Kemper Development Co., Madrona Venture Group, NHL Seattle, PEMCO Mutual Insurance Company and Seattle Children’s hospital. Seattle Times editors and reporters operate independently of our funders and maintain editorial control over Traffic Lab content.

Soils are so saturated that even a $16 million bluff-strengthening project in Mukilteo last decade isn’t enough to ensure safe travel in an area where the tracks run between steep slopes and Puget Sound.

Sound Transit made the decision to halt service following a small mudslide just south of Edmonds on Tuesday morning, combined with a look at US Geological Survey monitoring data in Mukilteo. Soils on the bluffs became soaked with water by Jan. 3 and currently exceed USGS thresholds for landslides “very likely to occur” if heavy rains arrive.

Advertising

Replacement buses will leave Everett Station at 6:15 a.m. and 7:15 a.m.; leave Mukilteo Station at 6:26 a.m. and 7:26 a.m.; and leave Edmonds Station at 6:41 and 7:41 a.m. Returning northbound, buses will leave King Street Station at 4:33 p.m. and 5:35 p.m. Additional service is available on Community Transit Route 416 in Edmonds, Route 417 in Mukilteo and Sound Transit Express Routes 510 and 512 in Everett.

Trains north of Seattle were previously suspended Christmas week when debris slid onto the tracks, and again part of last week, for a total 22 missed trips.

The North corridor served only 1,600 riders a day last year, and spokesperson John Gallagher said Tuesday the coronavirus epidemic has reduced that ridership by about 80%.

The Sounder South line linking Lakewood, Tacoma and Seattle, which operates mainly through valleys, remains on schedule.