One person was injured and taken to the hospital.
The National Weather Service sent teams to assess the damage and later confirmed that a tornado had touched down around 11:20 a.m.
Fire officials said city inspectors examined 17 buildings in the tornado-affected area, and 11 of them were red-tagged or marked unsuitable for use.
The tornado was an apparent landspout formed over Montebello.
It was part of a strong late-season Pacific storm that brought damaging winds and more rain and snow to saturated California.
The winter storms inspired not one but two tornadoes in California that week. A small tornado briefly touched down in Carpinteria on Tuesday night, damaging around two dozen mobile homes.
Tornadoes are rare in California because the environment is so isolated for these things to develop. They last only like a minute or two because of the stable marine layer always in place across California.