McKENZIE BRIDGE, Ore. (AP) - After a week of searching, rescue teams facing foul weather called off efforts to find a University of Oregon mathematics professor missing in the foothills of the Cascade Range.

Fog settled on the mountains Monday morning, and high winds whipped rain and sleet against the search parties.

"This was going to be the last day anyway," said Russell Gubele, command officer for Mountain Wave Search and Rescue. "It was becoming unsafe. The weather is really bad up there."

He said the search had been suspended indefinitely.

The Lane County Sheriff's Office described the status of the search for Daming Xu, 63, as passive rather than active.

"As weather permits and resources are available, search teams will continue searching for Xu," the sheriff's office said.

The on-site command post will be taken down.

Posters have been placed in the area, which will be reopened to hunting.

Over the weekend, Lane County sheriff's search and rescue coordinator John Miller said Xu's survival chances were "just about nil."

Xu was last seen on Nov. 4. He was an experienced hiker, but he apparently began his day hike east of Eugene without food, water, a warm jacket or a cell phone.

"All of us at the University of Oregon join the Xu family and our community with our thoughts and prayers during this very difficult time," said university President Dave Frohnmayer.

Many of Xu's colleagues in the mathematics department joined in the search effort and maintained a vigil alongside his family.