Set us as preferredA strengthening El Niño could bring the highest sea levels ever recorded to the California coast this year, raising the risk of widespread and damaging flooding. El Niño already is causing sea levels to rise in the eastern Pacific. “Flooding ... along the Southern California coast is likely to be a major issue for the winter season.” The World Meteorological Organization said on July 31 that a “strong El Niño is developing” and was expected to continue strengthening through early autumn. Even without El Niño, ocean temperatures have soared off parts of the coastline — a factor in the recent rounds of uncharacteristic muggy humidity.