The fierce debate over how bad California's El Niño winter will be

Key Points:

• Experts agree that coastal flooding and beach erosion risks are high this winter in California due to rising sea levels and strong surf, especially around king tides near major holidays.
• There is less consensus on the severity of winter storms and precipitation, with NOAA forecasting a 60-70% chance of above-normal rainfall in Southern California from January to March, but a significant chance remains for near- or below-normal precipitation.
• Climate models suggest the possibility of nearly double or more average precipitation in key coastal areas, with some experts warning of a top-10 wettest winter and potential record rainfall, urging emergency preparedness.
• The current El Niño is strengthening and likely to be one of the strongest on record, but past strong El Niños have produced varying rainfall outcomes, indicating that El Niño increases odds but does not guarantee extreme flooding.
• Sea levels along Southern California are at unprecedented highs due to a combination of El Niño, ocean warming, and astronomical tides, raising the risk of coastal flooding during storms, with forecasts of 2 to 3 feet above recent record peaks if storms coincide with king tides.