PORTLAND, Ore. - Roads leading to the Oregon coast were closed Monday as a series of powerful storms dumped heavy rain on the region, pushing smaller rivers and streams over their banks, downing trees across highways and causing mudslides.

Highways 26, 6, 18 and 30 all were closed Monday morning, isolating coastal communities. Many areas lost power as winds measuring near 100 mph battered towns and building. Trees blew over, buildings sustained damage and debris blew down streets in Tillamook, where the Wilson River began flowing down the lanes of Highway 101, which was also closed in several locations.

"This storm is hitting the coast so hard, it's not leaving any road open," Department of Transportation spokeswoman Christine Miles said.

According to KATU Meteorologist Rhonda Shelby, the stormy weather will be the strongest on Monday and should last into the late evening hours. The heaviest rain is expected to end after noon, however.

Officials issued a debris warning for Highway 6 and later expanded it to all other northern Oregon highways that run along rivers, saying earthen slides and other debris is expected to fall onto roadways. High water may also compromise roads.

Drivers are strongly urged to stay off roads leading to the coast until after the storm passes and the warning is lifted.

In Washington, officials prepared to closed the northbound lanes of Interstate 5 near Chehalis at about 11:15 a.m. due to high water on the highway. Officials there said there was going to be "no detour" around the closure as nearby roads were also flooded out. A full closure of the highway was under consideration.

Shortly after noon Monday, Washington Governor Christine Gregoire declared a statewide emergency in response to storms lashing Washington. Seattle received over 5 inches of rain in a 24-hour period.

According to KOMO-TV in Seattle, the Skokomish River set all-time record high levels Monday and major flooding was expected. The Chehalis River was also at record levels.

State Emergency Management officials in Washington said helicopter rescues were launched for stranded hikers in King County and flood-trapped homeowners in Mason and Thurston counties.

In Tillamook, Ore., the Wilson River was over its banks and flowing down Highway 101 through town. Power was out in large parts of the city during the morning and also in many towns along the northern Oregon coast. Closed highways had Tillamook almost completely isolated Monday morning.

Pacific Power reported that 37,000 customers were in the dark Monday morning, mostly along the northern coast. Power was restored to most customers as the day wore on but crews battled high winds and heavy rain to restore service.

Other utility companies reported scattered outages and said crews were working to repair downed power lines, many of which were hit by falling trees.

Coastal wind gusts were reported to be over 100 mph in some areas on Sunday. Some Willamette Valley locations had prepared for predicted gusts between 50 and 60 mph on Monday, but most inland areas had just blustery winds of not more than 30 mph.

Downed trees and debris slides closed many roads in the northwest part of the state.

Highway 26 linking the coast to the Willamette Valley was closed in the Coast Range due to treacherous conditions. Mudslides, downed trees and water over roadways also closed Highway 30 near the Columbia-Clatsop County line.

Highway 18 between Salem and Lincoln City was also closed. ODOT advised drivers not to go to the northern Oregon coast if at all possible. They urge motorists to check their Web site for specific roadway information and updates.

Aside from the high winds, the amount of rain falling on the Northwest is expected to lead to some flooding problems Monday and into Tuesday. In King City, rescue workers used rubber rafts to evacuate some residents as water rose around homes due to a blocked culvert. Many of the evacuees were seniors and some refused to leave.

The Southwest Barber Boulevard exit off Interstate 5 stranded several drivers Monday morning when standing water several feet deep swamped cars trying to make their way through. A plugged-up storm drain was suspected and road crews waded in to get the water drained. The exit was reopened.

The Columbia and Willamette rivers are not expected to flood, but smaller rivers and streams such as Fanno Creek and Johnson Creek in Portland quickly overran their banks as the deluge wore on. Use the links below to stay updated on rivers and streams near you:

• River forecasts and data
• Local bulletins and warnings
• Flood map
• Sandbag locations

The precipitation will mean plenty of new snow in the Cascades on Monday, where there is a winter storm warning. The snow level started at about 2,000 feet in the morning and rose to 4,000 feet later in the day Monday. It is expected to move to 8,000 feet late Monday as the storm moves through the area.

The rising snow level will mean more water in mountain streams and rivers due to melting snow and rainfall runoff, all of which could lead to more flooding.

In 2006, a powerful storm wiped out large section of Highway 35 between Mount Hood and Hood River. The current storm is not expected to cause similar damage.

The Red Cross set up shelters in the areas hardest hit by the storm, including St. Helens, Clatskanie, Vernonia, and Tillamook.

Vernonia was especially hard-hit and additional shelters were opened at Lincoln School, 7th-Day Adventist Church, and Cedar Ridge. The Red Cross shelter is also located at St. Mary's Church.

KATU Meteorologist Rod Hill said a dry stretch of weather may arrive Wednesday after the storm system moves east out of the area.

Sunday's Stormy Weather

As of 5 p.m. on Sunday, peak wind gusts along the Oregon coast were in the 80s and 90s, with a Bay City weather watcher registering an unconfirmed gust of 129 mph. Other recorded wind speeds included:

• Cannon Beach - 80
• Cape Meares - 109
• Lincoln City - 91
• Newport - 83

Although storm damage on Sunday was not widespread, some areas were hit hard. A KATU viewer sent in a picture of the Chinook Winds Casino in Lincoln City, which apparently had part of its exterior ripped off by high winds.

Further inland, the storm knocked out power to some homes in Washington County and Molalla. The power also went out near Kelso and Castle Rock. More power outages were reported around the region but crews were in the field working to get the power back on overnight Sunday and on Monday.

Peak wind gusts in and around the Willamette Valley area on Sunday were pretty tame with Salem having a peak gust of 44 mph. Some other winds speeds recorded Sunday included:

• Portland - 24
• Vancouver - 23
• Salem - 44
• McMinnville - 40
• Forest Grove - 38
• Corbett - 15