Tornado "not out of the question" for Southern California, says NWS

The National Weather Service has not ruled out the possibility of a tornado popping up during the latest atmospheric river on Sunday.

"We do have a lot of low-level rotation in the atmosphere that could spawn some waterspout activity over coastal waters," NWS meteorologist David Gomberg said. "And not out of the question that we could get a brief small tornado across the region."

Gomberg added that if a tornado were to happen, it would be Sunday night since the weather provides the "most favorable conditions." He reiterated that the possibility of one is very slim. 

Last year, a weak tornado briefly touched down in Montebello, injuring one person and damaging 17 buildings — 11 of which were red-tagged. The NWS classified it as an EF-1 and said it was the strongest to hit the Los Angeles County area since March 1983.

A trio of EF-0 tornados touched down last year also, wreaking havoc in Carpinteria, Carson and Compton. 

The ones in Carson and Compton damaged at least one building an car. However, the tornado in Carpinteria struck a mobile home park and damaged 26 residences.