The National Weather Service confirms the winds that damaged industrial buildings in western Washington, including a Boeing factory, were a tornado.
Meteorologist Johnny Burg says a team from the Weather Service office in Seattle went to the scene Monday and certified the tornado, based on eyewitness accounts.
The tornado at 7:20 a.m. tore a hole in the roof of the Northwest Door factory at Frederickson, halting production of garage doors.
The tornado also caused minor damage to the nearby Boeing factory and cars in the parking lot. Boeing says work has resumed.
The winds topped a weekend of record rains from a wintry storm in the Northwest.