The National Weather Service has issued a coastal flood advisory for Catalina and the Santa Barbara Islands, in effect until 2 p.m. on Friday, Oct. 30. The advisory was released at 11:39 a.m. on Wednesday, Oct. 28.
Forecasters at the NWS office serving Los Angeles and Oxnard said minor to moderate coastal flooding is expected because of very high tides. High tides are likely to reach 7.5 to 8.0 feet (MLLW) in the late morning on Thursday, which is 1.0 to 1.5 feet above astronomical projections.
Water levels should drop somewhat on Friday, but the NWS still expects tides near 7.5 feet (MLLW) around noon.
According to the agency, seawater is likely to flood vulnerable low-lying coastal areas, particularly around the time of high tide. Beach parking lots, bike paths and harbor walkways are among the places that could be affected. Moderate to significant beach erosion is also likely, and isolated damage to structures from seawater inundation is possible in the most vulnerable locations.
"Take the necessary actions to protect flood-prone property," the NWS said. "Do NOT drive around barricades or through water of unknown depth."
The advisory is one of several alert levels the weather service uses. A flood advisory means flooding is not expected to be bad enough to warrant a warning, but it may still cause significant inconvenience and could threaten life or property if caution is not exercised. A flood watch means conditions are favorable for flooding, which is possible but not certain. A flood warning is issued when flooding is imminent or already occurring, and a flash flood warning signals a sudden, violent flood that can develop in minutes to hours, even in areas not receiving rain.
The NWS also offers general flood safety guidance. People in flood-prone areas or camping in low-lying spots should move to higher ground, and anyone under an evacuation order should comply promptly and lock their home before leaving. If time allows, utilities and appliances should be disconnected to reduce electrical hazards. People should avoid flooded basements or rooms with electrical outlets or cords, and should leave immediately if they see sparks or hear buzzing, crackling, snapping or popping sounds.
The agency warns against walking through floodwaters, noting that even 6 inches of swiftly moving water can knock a person off their feet. Anyone trapped by moving water should reach the highest point possible and call 911. Drivers should never attempt to cross flooded roads, since as little as 12 inches of rushing water can sweep away most vehicles.
