High tides caused coastal flooding in Orange County on Monday, impacting communities from Newport Beach to Long Beach, as the region prepares for several days of near-record or record-high sea levels. The National Weather Service (NWS) has issued a coastal flood warning for Orange and San Diego counties, set to remain in effect through Thursday afternoon.
In Newport Beach, water surged from Newport Harbor onto the streets of the Balboa Peninsula, resulting in the flooding of some businesses within the Balboa Fun Zone. City crews responded by pumping out knee-high water and reinforcing sandbags along the harbor side of the Peninsula. Despite these impacts, city officials had not received reports of significant widespread damage as of Monday. Georgia Rios, a spokesperson for the city of Newport Beach, attributed this outcome to community preparedness, stating that approximately 25,000 sandbags were distributed over the weekend. Rios said the community's participation in taking sandbags contributed to "not having immense amount of flooding damage."
Long Beach residents reported flooding along Bayshore Beach, Naples, and the Peninsula. Officials in both cities had been actively preparing for the anticipated high tides by moving sand to fortify beaches, installing sandbags, and working to protect vulnerable areas that have experienced recent impacts. Residents in flood-prone zones were urged over the weekend to take precautions, including relocating vehicles to higher ground and protecting property with sandbags.
The extreme sea levels observed are a result of a rare convergence of factors. These include El Niño conditions contributing to an active eastern Pacific hurricane season, an ongoing marine heat wave, and an astronomical alignment that occurs approximately once every 20 years. Scientists explain that record-hot ocean water temperatures off California are elevating sea levels by 1.25 to 1.8 feet beyond what would be expected from the moon, Earth, and sun's gravitational movements alone. These ocean temperatures are influenced by human-caused climate change, an El Niño-fueled Kelvin wave, and a marine heat wave that has persisted for months. Reinhard Flick, a researcher at the Scripps Institution of Oceanography at UC San Diego, further detailed the impact of the 18.6-year lunar node tidal cycle and the 4.4-year lunar perigee tidal cycle, which arise from subtle changes in the moon's orbit and intensify tide-generating forces.
Total water levels in Orange County, along with Los Angeles and San Diego counties, could surpass 8 feet above the baseline—defined as the average daily lowest water level observed between 1983 and 2001. In Newport Beach, seawater levels reached 8 feet on Sunday and climbed to 8.3 feet on Monday, nearly 2 feet higher than the expected high tide alone. Forecasts indicate potential seawater levels on the city’s coastline could reach 8.5 feet on Tuesday at 9:50 a.m. and Wednesday at 10:28 a.m. The NWS warned that "Significant coastal flooding expected," noting that low-lying property, including homes, businesses, and some critical infrastructure, is at risk of inundation. The warning also indicated that some shoreline erosion is expected during the morning hours.
Farther south, the San Pedro tide gauge recorded 8.02 feet Monday morning, exceeding the previous record of 7.93 feet set in January 2005. In La Jolla, officials measured the sea level at 7.75 feet, close to its station record of 7.81 feet from November 2015, with expectations for it to potentially be broken given Tuesday's anticipated higher tides. The NWS has specifically warned that even higher sea levels are projected for Tuesday.
Looking ahead, coastal flooding is expected to intensify throughout the remainder of this year and into next year. Exceptionally extreme "king tides"—the annually anticipated highest tides around the Thanksgiving, Christmas, and Martin Luther King Jr. Day holidays—are projected due to the near-peak confluence of the lunar node and perigee tidal cycles. Scientists caution that if major storms coincide with these king tide events, the risk of coastal flooding will be further exacerbated.
