Noaa Hurricane: 63% chance of a very strong El Niño by year-end
The noaa hurricane story here is not a storm name but a forecast: NOAA’s Climate Prediction Center says there is a 63% chance the current El Niño will be very strong toward the end of the year. That outlook sits alongside an 88% chance that El Niño will be either very strong or strong.
Daniel Swain, a UC climate scientist, wrote that the event could become very strong or historic in magnitude and would likely lead to widespread and significant global impacts. For California and the West Coast, that means the season’s risk profile is already changing before the strongest impacts arrive.
NOAA Climate Prediction Center
NOAA’s Climate Prediction Center is putting firm numbers on the forecast. The center said the chance of a very strong El Niño reaches 63% toward the end of the year, and the broader chance of either strong or very strong conditions rises to 88%.
That matters because NOAA said El Niño is generally linked with stormier weather in the southern United States, while the Pacific Northwest generally gets drier winters. The timing also fits the period when El Niño impacts are usually felt most strongly, during winter.
California rainfall history
Swain said a very strong El Niño might be the single most important predictor of substantially increased odds of unusually wet conditions in California, and an early warning indicator of increased risk of large-scale flood events. He also wrote: “A very strong El Niño event might well be the single most important predictor of substantially increased odds of unusually wet conditions, and increased likelihood of individual heavy precipitation events, in any given winter in California — and perhaps also an early warning indicator of increased risk of large-scale flood events,”
The historical record gives that warning some weight. Of the last four very strong El Niños on record, the 1982-83 and 1997-98 events brought coastal Southern California more than double its typical annual rainfall. The 1991-92 event brought 133% of the average annual rainfall in coastal Southern California, and the 2015-16 event brought 77% of the annual average rainfall in the Southland.
West Coast flooding risk
NOAA said elevated sea levels along the West Coast can occur during El Niño, causing high tides and strong surf to ride higher and push further inland than normal. NOAA experts said the El Niños of 2015-16 and 2023-24 brought more frequent, deeper and widespread high-tide flooding, and the risk is made worse after decades of sea level rise.
The California Coastal Commission said the 2015-16 El Niño brought record coastal erosion along many California beaches. Major El Niño events can also raise local sea level by around six to 10 inches in California during the winter rainy and stormy season, adding another layer to the forecast for coastal communities already watching the shoreline.
Colorado River basin drought
Swain wrote that a wet winter could bring some relief to the Colorado River basin, which is in an exceptionally severe multi-decadal drought. But he also cautioned that the same high-end El Niño could produce effects that have not been seen in the modern era, given the combination of a strong event and over a century of accumulated global warming.
He wrote: “The recently observed and ongoing rapid escalation of conditions in the tropical Pacific, plus the consistently and increasingly extreme forward-looking model projections, truly do suggest that something extraordinary could unfold,” and added that the event could lead to “widespread and significant global impacts.” For people in California, the practical question is whether the winter brings a wet pattern that helps reservoirs and soils, or one concentrated enough to drive flooding and coastal damage in a few hard-hit storms.
