On motion of a party made not later than thirty days after an arbitrator gives notice under RCW 26.14.140(1) of an award, the arbitrator may correct the award:
(1) If the award has an evident mathematical miscalculation or an evident mistake in the description of a person, thing, or property;
(2) If the award is imperfect in a matter of form not affecting the merits on the issues submitted; or
(3) To clarify the award.