The tornado was the smallest type, an EF-0, with estimated peak wind speeds of 75 mph, said Ted Buehner of the National Weather Service in Seattle.
He said a storm survey team visited Eatonville on Monday and determined that Sunday's tornado had touched down for less than one minute and created a path about a fifth of a mile in length and about 25 yards wide.
The twister ripped away a carport roof, damaged a utility pole and knocked down a road sign.
The carport belonged to Michael Tonkin, who said he heard his whole house shake.
"Thought it was an earthquake and walked outside and it was all gone," he said.
His carport roof was now on the other side of the road, a pontoon boat inside still missing.
"I just looked and everything was everywhereI didn't know what the hell happened," he said.
Robin McClyde, who works at a fast food restaurant in the area, also witnessed the twister.
"I looked out the window and I saw a tornado," she said. "It was swirling pretty good."
She said it caused some damage to a neighbor's home and then briefly knocked out power.
"Then it dispersed and dropped all the debris in the road," she said.
It's the first confirmed tornado in Western Washington since an EF-1 tornado touched down in Frederickson in September.
The storm also brought a burst of heavy rain and nickel-sized hail.