Weather service extends Southern California flood advisories to Friday afternoon

The National Weather Service extended flood advisories for Southern California's coastal counties through 2 p.m. Friday, adding a day to warnings that had been scheduled to expire Thursday at 1 p.m.

Devin Black, a meteorologist with the weather service's Oxnard office, confirmed the extension on Wednesday. Orange and San Diego counties, previously under a more severe flood warning through Thursday afternoon, were downgraded to a coastal advisory running through Friday afternoon.

The weather service received reports of seawater over low-lying areas, Black said, and some structures had shallow water reaching the base of the building. Long Beach has been a main area of concern for several weeks and remains the most acutely affected city, he said. Tides were expected to approach 8 feet Thursday morning before gradually subsiding into the weekend.

Some tides this week set records. The San Pedro tide gauge reached 8.02 feet Monday morning, passing the previous record of 7.93 feet recorded in January 2005. Other gauges across Southern California approached record levels, including in La Jolla. Black described the readings as "definitely on the extreme end." High tides occurred across the region, but the angle and magnitude of swells also played a role, he said; San Diego and Orange counties faced higher risk because they were more exposed to a southwesterly swell.

The current conditions may preview higher tides expected around the Thanksgiving, Christmas and Martin Luther King Jr. Day holidays. A weather system is expected to move over the region Saturday and Sunday, possibly bringing rain to Los Angeles.