Sea levels reach 1.9 feet above normal in California, triggering coastal flooding

Coastal communities along both the Pacific and Atlantic Oceans faced street flooding and property damage this week as king tides pushed water levels well above average. The surge began with the full moon earlier in the week and is expected to persist through the weekend, according to National Weather Service forecasters. These events occur when the gravitational pull of the sun and moon aligns with the Earth, a phenomenon that happens several times a year but can last for several days.

Forecasters cited specific meteorological factors that amplified this week's tides beyond typical king tide levels. In Florida, Chris Fisher, a meteorologist with the NWS in Miami, identified strong high pressure to the north and low pressure over the Caribbean as drivers for increased swells. Along the California coast, Roger Gass, a meteorologist at the Bay Area forecast office in Monterey, pointed to the ongoing super El Niño warming ocean waters and increasing volume. He also noted that Kelvin waves, which are pulses of warm water, further lifted sea levels.

Residents in Southern California dealt with the rising water on Wednesday. In Huntington Beach, people placed sandbags outside homes to block floodwaters. Some locals used paddleboards and surfboards to travel through flooded streets. The Pacific Coast Highway saw multiple closures, and tides were expected to approach record levels in Orange and San Diego counties. In Northern California, minor flooding was forecast for low-lying shoreline areas through Saturday.

Gass stated that coastal flooding generally occurs within 1.5 hours before and after high tides. In Northern California, high tides are peaking 1.9 feet, or about a half-meter, above normal levels. This metric provides a concrete measure of the anomaly affecting the region's infrastructure and homes.

Along the Atlantic, flood warnings covered most of Florida's coast through early Friday. Street flooding was reported in Charleston and Myrtle Beach, South Carolina. Rip currents were possible as far north as North Carolina's Outer Banks. Fisher described the conditions as rough, noting a high risk of rip currents and high surf that would continue through the weekend.

In Fort Lauderdale, Florida, access to waterfront venues at a major boat show required driving through flooded streets adjacent to marinas and hotels. In Miami, the barrier island of Virginia Key recorded its highest king tide and the third-highest water level in three decades of records. Fisher noted that only hurricanes have produced higher water levels in recent history.

Fisher advised residents to stay out of the water and away from beaches through the weekend due to persistent rough conditions. The NWS maintained that the combination of lunar alignment and atmospheric factors created a unique flooding scenario for this week.