EVERETT — Longtime Snohomish County Superior Court Judge James Allendoerfer plans to step down from the bench for health reasons.

Allendoerfer, of Mukilteo, has been undergoing treatment for brain cancer since mid-April.

He made clear earlier this week that he won’t return to the bench. His resignation is effective Wednesday.

Letters have been sent to County Executive Aaron Reardon as well as Gov. Chris Gregoire, who may appoint his successor.

Presiding Superior Court Judge Larry McKeeman said he’d just received word of his colleague’s decision Friday morning.

Allendoerfer was first elected to the bench in 1990 and took office the following year. He is the second-longest seated jurist on the county’s 15-person panel.

Three years remain of his current term.

County officials expect that there will be an election in November to fill the vacated position.

Resignations received 11 weeks before the general election allow the auditor’s office to put the position on the November ballot, Snohomish County Auditor Carolyn Weikel said.

A special three-day filing period likely will occur after the Aug. 18 primary election, she said.

It was unclear Friday if Gregoire will appoint someone to the fill position until the voter-selected candidate takes office in January.

The governor is tasked with appointing Superior Court judges to fill vacancies that occur outside the election cycle.

The appointment process can take months, Superior Court Administrator Bob Terwilliger said.

“Applicants may be applying with the governor and running for election at the same time,” he said.

The Snohomish County Bar Association typically conducts a poll to rate those seeking appointment.

Governors usually rely on the bar associations’ recommendations.

Gregoire last appointed a judge to the county Superior Court in 2007 after a new position was funded. She picked Bruce Weiss, who was elected last fall.

Two other Superior Court judges are out on medical leave.

Judges George Bowden and Ronald Castleberry are expected to return to the bench later this fall.

Diana Hefley: 425-339-3463, hefley@heraldnet.com.