The National Weather Service issued flash flood warnings for parts of Southern California on Sunday morning as rain associated with Post-Tropical Cyclone Rachel moved through the region.

A warning issued around 4 a.m. covered parts of southern Orange County. Portions of Riverside and Imperial counties also faced a threat of dangerous flooding.

On the coast, waves have heavily damaged the Alamitos Peninsula waterfront in Long Beach. The city red-tagged eight structures covering 13 addresses, and crews deployed heavy sandbags to support a failing bulkhead. Newport Beach closed Newport Pier, Balboa Pier and the Wedge after streets flooded on Friday.

Forecasters expected eight-foot tides Sunday morning and warned that severe, damaging ocean flooding was likely at south-facing beaches. How much further damage the storm might cause remained unclear.