Passengers on Sound Transit should prepare for serious delays this morning on buses and trains because of the weather.

Power outages, frozen switches and frozen overhead lines have interrupted the train system and schedule. Treacherous streets have impacted buses heading into downtown Seattle, said Sound Transit spokesman Geoff Patrick.

Passengers on these bus routes: 577,578,586,590,593,594,595 should anticipate possible delays and changes in service. These passengers will be dropped off at the Royal Brougham station and then shuttled into downtown, Patrick said.

The freezing rain and fallen trees also disrupted bus routes elsewhere in King County Thursday morning, Metro Transit spokeswoman Linda Thielke said.

About a dozen buses were stuck earlier Thursday, but Thielke said that got worse as the morning commute picked up. She wasn't sure how many buses were stuck around 8:30 a.m., but said it was fewer than on Wednesday.

In some places, she said, buses had to turn around because roads were closed or fallen trees and car accidents made them impassable. For example, she said, the bus that usually runs between Fall City and Snoqualmie was not able to get all the way to Snoqualmie Thursday morning.

"I think people inside Seattle might know that it's icy, but they might not understand how icy it is in some areas," she said.

Thielke said the best thing for people to do is to stay home. Individual trips are "unpredictable," she said. To learn whether a snow route is running at all, travelers can visit kingcounty.gov/metro/snow or call 206-553-3000.

Sounder and Link light-rail lines are seeing delays of up to 25 minutes. One train had to be taken to the maintenance yard because of mechanical troubles; passengers were loaded onto a different train, said agency spokeswoman Kimberly Reason.

"We're experiencing delays in both directions," Reason said, adding that passengers should sign up for Web alerts.