SNOQUALMIE, Wash. — More than 30,000 people have been urged to leave their flood-endangered Western Washington homes as snowmelt and rain swelled rivers cause mudslides and avalanches that are engulfing neighborhoods and roadways.

Though the pounding rain that melted mountain snow and caused the flooding eased today, flood warnings remain in effect for 14 counties in Western Washington and seven on the state’s east side. The National Weather Service further warns that rain-soaked hillsides are at a high risk for landslides.

Rising waters led state highway crews to close a 20-mile stretch of Interstate 5 around Chehalis on Wednesday evening, the same area hit by a devastating flood just 13 months earlier. All three major east-west routes across the Cascade Range also were closed by avalanches and the threat slides.

“It’s right up there with some of our most memorable flood events,” National Weather Service forecaster Doug McDonnal said today. “The thing that’s kind of amazing in the past few years is how many flood episodes we’ve had.”

Highway officials hoped to reopen one main route across the mountains sometime today — likely Interstate 90 across Snoqualmie Pass.

“The most unfortunate part of this is all three passes are closed,” state Transportation Secretary Paula Hammond said. “We’re in a place until we can open Snoqualmie Pass, which is our first best hope, we’re in a real bind in this state.”

Flooding in December 2007 closed I-5 at Chehalis for four days and caused widespread damage in the area halfway between Seattle and Portland.

Hammond visited the scene this morning and said: “It’s just deja vu, I tell you. Water everywhere.”

The Chehalis River was forecast to crest tonight and by Friday crews planned to use pumps and breach a levy to help the water drain out.

The National Weather Service issued flood warnings for about two dozen rivers in Western Washington. Amtrak passenger train service out of Seattle was suspended due to mudslides.

McDonnal said that with steady rain turning to showers in Western Washington, most rivers should drop below flood stage Friday but some, like the Chehalis, won’t return to their banks until the weekend.

Warmer temperatures and heavy rains were rapidly melting the record levels of snow that dumped on the Cascade mountains over the weekend. Ten inches of snow melted in a 12-hour period at Snoqualmie Pass, according to weather service meteorologist Andy Haner.

Fire trucks rolled through Orting, about 10 miles southeast of Tacoma, with loudspeakers Wednesday, advising everyone to leave the town and surrounding valley, home to about 26,000 people. Sandbags were placed around many downtown homes and businesses as the Puyallup River neared record levels.

Tacoma Mayor Bill Baarsma declared a civil emergency for his city of about 200,000, south of Seattle, largely because of Puyallup River flooding risks to the city’s wastewater treatment plant.

Chris Caviezel, who has lived at Snoqualmie Pass for about seven years, said conditions were the worst he has seen. “We’re getting avalanches and we’re being flooded,” Caviezel said.

In Snoqualmie, kayakers paddled in the street as city officials urged residents in the flood plain of the Snoqualmie River to leave before they became trapped.

Rachel Myers stood across a flooded parking lot from her home and waited for her father to pick her up in a boat. She said her family has lived in the house since her great-grandmother built it, but they’ve decided this will be their last winter there.

“With flood after flood, it just gets more ruined every time,” Myers said.

In the east, Spokane, already beset by more than 6 feet of snow in the past three weeks, was hit with rain and temperatures in the mid-40s, triggering a flood warning for the area. The city’s schools were closed today, giving its 29,000 students a third unscheduled day off this week.