The service also issued and then canceled a tornado warning for central Orange County shortly after midnight. The warning applied to areas including Newport Beach, Costa Mesa, Santa Ana and Irvine.
The service said a "severe thunderstorm likely producing a tornado" was observed shortly before 10 p.m. near far eastern portions of Santa Barbara, Montecito, Carpinteria and Summerland. It will continue to move north into the Santa Ynez Mountains.
Residents in the area are warned to seek shelter and that flying debris can cause damage to buildings, vehicles and trees, along with people outside.
By about 10:30 p.m. the service said the warning was canceled and the storm had slightly weakened.
While the tornado warning was active, the service advised:
"TAKE COVER NOW! Move to a basement or an interior room on the lowest floor of a sturdy building. Avoid windows. If you are outdoors, in a mobile home, or in a vehicle, move to the closest substantial shelter and protect yourself from flying debris."
Hail the size of pennies was also possible, the NWS said. The impacted area was estimated to have a population of about 23,000.
Tornado Warning including Carpinteria CA, Montecito CA, Summerland CA until 10:30 PM PST pic.twitter.com/rSsMTqGyMA— NWS Los Angeles (@NWSLosAngeles) December 26, 2019