California might see a 'super' El Niño this year

Forecasts from major climate centers show a high chance of El Niño developing by fall, and models indicate sea surface temperatures could reach levels some call a 'super' El Niño; such events tend to increase the likelihood of wetter winters in Southern California while also raising risks of flooding, debris flows and coastal erosion.

Forecasters are reporting growing signals that a strong El Niño could form later this year, and some model runs suggest sea surface temperatures in the tropical Pacific may rise to levels described as "super" El Niño. Agencies including the European Center for Medium-Range Weather Forecasts and the National Oceanic and Atmospheric Administration have released outlooks that raise the probability of a significant event this fall. Experts note that while strong El Niños often shift storm tracks and increase Southern California rainfall, the exact local outcomes remain uncertain. Scientists say the situation generally becomes clearer as late spring and early summer observations are incorporated into models. Key points: - The European Center for Medium-Range Weather Forecasts indicated sea surface temperatures could exceed the seasonal average by about 2 degrees Celsius, a threshold some use to label a "super" El Niño. - NOAA forecasts a greater than 90% chance that an El Niño will develop by fall and estimates about a 50% chance it will be at least a strong event; it also gives roughly a 1-in-4 chance of exceeding the 2°C threshold by late fall. - Strong El Niño conditions tend to steer the subtropical jet stream southward, which can increase the odds of wetter winters in Southern California and may lower some seasonal wildfire risks while increasing flooding, debris flow and coastal erosion risks. Summary: Forecasts point to a likely El Niño with the potential for wetter winters in Southern California and associated rises in flood, debris flow and coastal erosion risk while also easing some seasonal wildfire pressure. Significant uncertainty remains about exact impacts, and scientists say the picture typically becomes clearer between late May and June. Undetermined at this time.