Coastal communities across Southern California are bracing for more flooding Thursday and Friday as El Niño conditions keep water levels very high.
The forecast
Unusually high tides that caused flooding in low-lying areas of Southern California, including Newport Beach and Long Beach, may persist longer than initially expected.
The National Weather Service on Wednesday extended flood advisories for all coastal counties in Southern California until 2 p.m. Friday, said Devin Black, a meteorologist at the weather service’s Oxnard office. They were initially scheduled to expire on Thursday at 1 p.m.
Orange and San Diego counties, which were under a more severe flood warning until Thursday afternoon, will be downgraded to a coastal advisory until Friday afternoon.
The weather service found that “seawater covered low-lying areas,” Black said, and “some structures had shallow water all the way to the base of the building.”
High tide floods businesses and homes along Pacific Coast Highway in Sunset Beach.
(Robert Gauthier/Los Angeles Times)
The impact
The Balboa neighborhood of Newport Beach experienced widespread flooding this week. Sunset Beach is another hard-hit area, where several streets have been flooded and the Pacific Coast Highway is closed. Caltrans also plans to close PCH for part of Thursday.
Long Beach was hardest hit on Thursday and has been a major area of concern for weeks, Black said.
Tides are expected to approach 8 feet Thursday morning, then gradually decrease over the weekend.
Some tides this week were record-breaking: “They were definitely on the extreme side,” Black said.
The San Pedro tide gauge in Los Angeles Harbor had its record broken Tuesday, reaching 8.19 feet. This is the highest level since records were first kept in November 1923.
In Santa Barbara, high tide reached a record 8.04 feet Tuesday before receding slightly Wednesday, said Ryan Kittell, meteorologist for the NWS in Oxnard.
In La Jolla, the tide reached 7.98 feet Tuesday, breaking the November 2015 record of 7.83 feet.
At the San Diego tide gauge, Tuesday’s high tide was a record 8.52 feet, breaking the previous record of 8.26 feet from last July.
“Tuesday was a record and Wednesday was a similar but slightly lower record,” and tides are expected to drop throughout the week, Kittell said.
It remains unclear whether the upcoming winter king tides in the coming months will break these records again. “We’ll just have to wait and see,” he said.
Even though tides were high throughout the region, “the angle and magnitude of the swells is also a huge factor,” Black said, so the risk for San Diego and Orange counties was higher because they were more exposed to a southwest swell.
What’s next?
For coastal communities, this could be the start of a long winter season. Even higher tides are expected during the Thanksgiving, Christmas and Martin Luther King Jr. holidays, and if a strong storm arrives during these times, it could lead to even more severe flooding.
Something similar happened during the historic storm of late January 1983, which occurred during one of the strongest El Niños on record and struck the coast up and down California, damaging many piers. A strong storm arrived precisely at a time of the month when the tides were very high.
Although the pace of coastal flooding may seem incredible to some, it was predicted a few months ago, at a town hall where Mark Merrifield, director of UC San Diego’s Center for Climate Change Impacts and Adaptation, warned that he expected “probably the highest sea levels ever recorded on the California coast associated with this event,” referring to a strengthening El Niño. “Flooding…along the Southern California coast will likely be a major problem for the winter season.”
What is happening?
Ocean temperatures have been affected not only by human-caused climate change, but also by an El Niño-fueled Kelvin wave that brings warmer water from the equatorial Pacific Ocean along the coasts of the Americas, and by a months-old marine heat wave unrelated to El Niño.
Scientists say this marine heatwave caused sea water levels to rise 1.25 to 1.8 feet above what they would have been due to the simple movement of the Moon, Earth and Sun.
Gn usa
