During any vacancy that occurs in a single judge court pursuant to RCW 3.50.093 or 3.50.095, a presiding judge pro tempore who has been predesignated pursuant to court rule or appointed pursuant to RCW 2.56.040(2) may fulfill presiding judge duties, and the authority of the predesignated or appointed presiding judge pro tempore endures until the chief justice appoints someone else to fulfill the presiding judge duties pursuant to RCW 2.56.040(2)(b), or until a vacancy in the position is filled as provided by law, whichever occurs first.