A rare tornado touched down in a Seattle suburb on Tuesday, damaging several homes and toppling trees, authorities said.

Based on radar imagery and video evidence, a tornado touched down south of Port Orchard shortly before 2 p.m., the National Weather Service in Seattle said on Twitter.

There were no immediate reports of injuries.

Emily Silverman told a local television station she was driving to a store with her husband at the time.

National Weather Service in Seattle can confirm that a tornado touched down near Port Orchard just before 2pm on December 18. An extensive, official damage survey will be conducted by the NWS Wednesday morning. Until then, the strength of the tornado can't be determined. <a href="https://twitter.com/hashtag/WAwx?src=hash&ref_src=twsrc%5Etfw">#WAwx</a> <a href="https://t.co/Hs1MVIkzoz">pic.twitter.com/Hs1MVIkzoz</a> —@NWSSeattle

"It's raining and it's pouring down really bad and before you know it everything was flying everywhere," Silverman said.

"Our car back windows blew out, our side windows blew out ... I thought I was a goner."

Her two-year-old son was in the back seat.

"So glad he's OK because the whole back window just busted in," Silverman said. "It was just crazy. I've never seen anything like this in my life."

Damage has been reported on Rhapsody Drive and at the Bethel Tavern.

Based on radar imagery and video evidence, a tornado touched down south of Port Orchard shortly before 2 p.m. (KOMO-TV)

Video from the television station's helicopter at the scene showed trees down, homes with roofs ripped off and debris scattered across yards.

The weather service said it wouldn't be able to survey the area before it was dark and that it would send a team Wednesday morning. It said it was working with emergency management partners to learn the extent of the damage.

Port Orchard is about 24 kilometres west of Seattle, across Puget Sound.