CALIFORNIA, Sept. 10 (Our California Times) — NOAA is giving El Niño a 97% chance of reaching “Super El Niño” strength during fall and winter and continuing into early spring. The forecast covers a period when California could see a greater chance of wet weather, especially in Southern California from December through March.
The forecast is not a California storm warning. It is a seasonal climate outlook, meaning it describes the odds of broad weather patterns rather than predicting a specific storm, rainfall total or flooding event.
For now, Californians should rely on forecasts from the National Weather Service and local emergency officials for day-to-day decisions. People planning coastal activities should check marine and surf forecasts, especially when storms are approaching.
What is El Niño?
El Niño is a periodic warming of surface waters in the central and eastern tropical Pacific Ocean. That warming can shift the jet stream and alter winds around the world, changing the odds of rain, drought and tropical-storm activity in different regions.
A “Super El Niño” is a term used for an unusually strong event. The supplied NOAA-related forecasts describe that level as involving equatorial Pacific waters at least 2 degrees Celsius above average for three consecutive months. The available observations described in July and August showed temperatures near 1.4 degrees above average, so the forecast threshold and the observed conditions were not the same thing at that time.
NOAA’s September outlook raised the chance of Super El Niño conditions during fall and winter to 97%. It also put the chance of the event reaching historic strength between October and December at 75%. Earlier NOAA outlooks had put the chance of an event ranking among the strongest on record at 90% in August and 81% in July.
Those percentages refer to different forecast updates and, in some cases, different definitions of strength. They should be read as changing probabilities, not as separate guarantees.
Why the Atlantic is quieter
El Niño often increases high-altitude winds over the Atlantic tropics. Those winds, known as wind shear, can tilt or tear apart developing tropical systems and make it harder for hurricanes to form or strengthen.
NOAA’s Climate Prediction Center said in a July 28 outlook that tropical-cyclone formation was unlikely over the Caribbean and central Atlantic “for the foreseeable future.” AccuWeather hurricane forecaster Alex DaSilva said the stronger El Niño becomes, the greater the likelihood of a less active end to the Atlantic season.
That pattern does not mean the Atlantic is safe from hurricanes. A single storm can still cause serious damage, and local conditions can overcome a broad seasonal pattern. The National Hurricane Center continues to monitor individual systems regardless of the larger climate signal.
Why the Pacific can become more active
The same ocean and atmospheric pattern that suppresses Atlantic storms can favor tropical activity in the eastern and central Pacific. El Niño tends to place warmer water and more supportive upper-level winds in parts of that basin.
That can raise the odds of stronger eastern Pacific hurricanes. For California, the most relevant effects are not a forecast that a hurricane will strike the state, but the possibility of larger ocean swells, dangerous surf and coastal flooding when Pacific storms pass offshore.
The reported California impacts are seasonal possibilities, not issued emergency warnings. No specific California rainfall amount, wave height, flooding threshold or local impact date was included in the outlooks summarized here.
What California could see this winter
Alexander Gershunov, a research meteorologist at Scripps Institution of Oceanography at UC San Diego, said the pattern raises the likelihood of above-average precipitation in Southern California, particularly from December onward. Michelle L’Heureux identified January through March as the prime period for potential impacts.
A wetter winter can bring benefits, including improved water supplies, but it can also increase the risk of flooding, mudslides and travel disruptions when storms arrive. The effects will depend on where storms track, how quickly rain falls and conditions on the ground at the time.
The forecast also does not determine whether a particular city, watershed or coastline will flood. Those questions require shorter-range forecasts issued as storms develop.
The practical takeaway is to prepare for a changeable winter without treating the seasonal outlook as a specific disaster prediction. Residents can keep up with National Weather Service forecasts, review local flood and evacuation information, and check official coastal conditions before traveling to beaches or other exposed areas. Times of highest concern will become clearer as individual storms enter the forecast window.
