WASHINGTON, July 7 (San Diego News Online) — El Niño is now underway in the tropical Pacific, and NOAA forecasters say it is expected to strengthen through the Northern Hemisphere winter of 2026-27.
The Climate Prediction Center issued an El Niño Advisory on June 11 and said El Niño conditions are present. In its diagnostic discussion, the federal forecasting office said the latest weekly Niño-3.4 index was +0.7 degrees Celsius, with the Niño-4 index also at +0.7 C and the Niño-1+2 index at +2.1 C. NOAA said model guidance, including the NCEP CFSv2 and the North American Multi-Model Ensemble, points to further strengthening, and it put the chance of a very strong El Niño at 63% for November-January.
For readers, the main takeaway is simple: watch the forecasts, but do not overread one advisory. El Niño can tilt the odds for rain, temperature and storms, yet the effects vary by region. People with winter travel plans, coastal property or weather-sensitive work should keep checking NOAA seasonal outlooks and local forecasts as the season develops.
What is El Niño?
El Niño is the warm phase of ENSO, short for El Niño-Southern Oscillation. It happens when sea surface temperatures in the central and eastern equatorial Pacific run warmer than average and the ocean and atmosphere begin to shift together. NOAA uses those Pacific temperatures, along with wind and pressure signs, to decide whether El Niño, La Niña or neutral conditions are in place.
What NOAA is seeing now
NOAA says El Niño conditions developed over the past month after above-average sea surface temperatures spread across the central to eastern equatorial Pacific. In the agency’s technical summary, the warming first showed up in the far eastern Pacific in early February and expanded across the central and eastern Pacific by mid-April.
A separate forecast page from IRI Columbia says El Niño conditions are strengthening across the tropical Pacific and says the latest weekly Niño-3.4 index reached +1.7 C on June 17. That page says the event is likely to keep intensifying.
Why the advisory matters
An El Niño Advisory does not mean one city will get a certain kind of winter. Instead, it tells forecasters that the Pacific is in a state that can change the odds for seasonal weather patterns.
In general, El Niño can affect where storms track, how much rain falls and how warm or cool a season turns out. But those changes are not the same everywhere. NOAA says a very strong event this winter could rank among the largest in the historical record going back to 1950.
For coastal communities, NOAA’s Ocean Service says El Niño can raise the risk of high-tide flooding in some U.S. locations. That makes tide forecasts and local flood alerts worth following more closely as winter approaches.
The bottom line
NOAA’s current message is straightforward: El Niño is here, and forecasters expect it to strengthen heading into winter. The best next step is to keep an eye on NOAA updates and local weather forecasts for region-specific guidance.
