Soggy weather triggers slides

With forecasters calling for more rain today and Sunday night, the soggy Seattle area could see more landslides like the ones that shut down passenger-rail service between the city and Everett.

On Friday, the U.S. Geological Survey (USGS) issued an advisory that if 1 inch of rain fell in a 24-hour period in the next few days, it would likely be enough to trigger more slides in King, Snohomish and Pierce counties.

In Seattle, "it's rained almost every day for the past couple of weeks," said Rex Baum, the USGS research geologist responsible for monitoring the Puget Sound region's probability of slides. "A half-inch there, a quarter-inch here, and it adds up over time."

The prolonged rainfall triggered four landslides between Seattle and Edmonds, along BNSF Railway lines early Friday.

Nearly 1.5 inches of rain fell at Seattle-Tacoma International Airport between 4 a.m. Thursday and 4 a.m. Friday, according to the National Weather Service. During the same period, 0.93 of an inch of rain fell in Everett. Baum said his prediction that an inch of rainfall in a 24-hour period could cause hillsides to slip may be overly cautious, but he wanted to draw attention to the situation. "I hope that it will take more [rain] than that, but I'm trying to be on the cautious side because it is already so wet right now," Baum said.

According to the USGS, steep coastal bluffs and hillsides are particularly susceptible to landslides under current conditions.

The National Weather Service is forecasting a half-inch of rain to fall Saturday with another quarter-inch falling Sunday in Seattle, said meteorologist Johnny Burg. "Early Monday, we have another rain band moving in that's looking to dump a lot of precipitation, but that's still a long way off" and the forecast may change, he said.

Travel updates

Commuters who ride the Sounder train between Everett and Seattle should look for updates about Monday service by visiting www.soundtransit.org or calling Sound Transit's rider information line at 888-889-6368.

Amtrak passengers with questions about the service interruption can call 800-USA-RAIL, or visit Amtrak.com.

Tips for preparing for, and responding to, landslides are posted on the U.S. Geological Survey's Web site at http://landslides.usgs.gov/learningeducation/hazards.php

Burg said that during the 10-day period ended Dec. 30, at least 0.33 of an inch of rain fell each day in Seattle. Since 1931, the longest consecutive stretch of similar rain patterns was eight days. On Dec. 31, 0.3 of an inch fell.

As of midnight Thursday, Burg said, the Seattle area had recorded 1.88 inches of rainfall so far this year. The norm is 0.85 inches, he said.

"We've been pretty well-saturated at this point," Burg said.

Gus Melonas, a spokesman for BNSF Railway, said cleanup operations after Friday's landslides were completed by noon.

Around 1 a.m., a track inspector discovered the first and largest slide from a slope in Ballard, between Golden Gardens and Carkeek parks, Melonas said. Mud nearly 3 feet deep and covering an area 30 feet long covered one of two sets of train tracks at the spot, he said. Within an hour, three more slides, two of them minor, occurred.

Trees up to 70 feet high were swept down a hillside, landing on the tracks between Mukilteo and Edmonds, Melonas said. In two other slides — one about a mile north of Golden Gardens Park and the other, two miles south of Mukilteo — a small amount of mud set off sensors in an electronic fence that warns of any slope movement but didn't impact the tracks, he said.

Although the tracks had been cleared of debris by early Friday, federal law requires that passenger train service be halted for 48 hours following a landslide to ensure that the slope and rail bed have stabilized, Melonas explained. Barring more rain and slides, the tracks will reopen to Amtrak passenger trains early Sunday, he said.

Because only one set of tracks was covered by mud, freight trains were allowed to travel the route at reduced speed, he said. "We'll be keeping a close eye on the track and on the slopes," Melonas said.

Sound Transit spokesman Lee Somerstein said there was no Sounder train service between Seattle and Everett Friday afternoon because of the 48-hour rule. Additional buses were sent to the Everett transit station to help commuters get to work Friday morning, he said. So-called "street ambassadors" were also dispatched to the station to notify people of the slides and direct them to buses, Somerstein said.

The Sounder doesn't run on weekends, except for special trains to sports events. The Seahawks aren't playing this weekend.

Bus service will be used during the track closure for Amtrak's four north-south trains, two each between Seattle and Bellingham and between Seattle and Vancouver, B.C., Melonas said. For the two daily runs between Chicago and Seattle, a route that goes through Everett, passengers will be bused between Seattle and Everett, he said.

Melonas said landslides are not uncommon this time of year.

On Christmas Day, a slide occurred south of Tacoma, covering both tracks in mud 3 feet deep and 30 feet long. Buses were used to shuttle Amtrak passengers between Seattle and Portland, he said.

Sara Jean Green: 206-515-5654 or sgreen@seattletimes.com

Information from The Associated Press is included in this report.