The National Weather Service says a tornado touched down near Shelton, Mason County.
KOMO television reports the tornado on Friday night had winds up to 100 mph.
The tornado started on land and traveled more than a half-mile before moving over the waters of Pickering Passage and becoming a waterspout. It dissipated after moving over the water.
On land, the tornado cut a path about 90 yards wide. It was on the ground for about five minutes. The twister uprooted trees. Falling trees damaged at least two homes.
The tornado is the second in the South Sound this year. A weak tornado touched down Oct. 4 near Tenino.