Strong El Niño now a virtual certainty: What it means for California

Key Points:

• Federal scientists from NOAA's Climate Prediction Center report a 97% chance of a strong or very strong El Niño developing by December, with an 81% likelihood of it being very strong, potentially ranking among the strongest on record.
• In California, a strong El Niño typically increases the chance of above-average winter rainfall in Southern California, raising risks of flash floods and landslides, while also intensifying heat waves on land and sea, exacerbated by climate change.
• Recent ocean temperatures in the tropical Pacific are among the warmest recorded, fueling the El Niño pattern that weakens trade winds and shifts the winter jet stream southward, often bringing more storms to Southern California.
• The ongoing El Niño is expected to prolong marine heat waves off the California coast, which have persisted since last year, and contribute to extreme weather events globally, including fueling Super Typhoon Bavi approaching Taiwan.
• Beyond California, El Niño typically brings wetter winters to the southern U.S., southern South America, and parts of the Horn of Africa and central Asia, according to the World Meteorological Organization.