WASHINGTON, July 7 (San Diego News Online) — NOAA forecasters say El Niño is already present and is expected to strengthen through the Northern Hemisphere winter of 2026-27. The Climate Prediction Center issued an El Niño Advisory on June 11, giving the official federal signal that the warming pattern in the equatorial Pacific has moved into El Niño conditions.
For most readers, the practical step is simple: keep an eye on seasonal forecasts as winter approaches. People in coastal areas should also watch local tide and flood notices, because NOAA’s Ocean Service says El Niño can raise the risk of high-tide flooding in some U.S. locations.
What is El Niño?
El Niño is the warm phase of ENSO, short for El Niño-Southern Oscillation. It is part of a repeating pattern in the tropical Pacific that can influence weather far beyond the ocean itself. NOAA tracks it by measuring sea-surface temperatures and winds across the equatorial Pacific.
In its latest advisory, NOAA said the central to eastern equatorial Pacific has been running above average. The Climate Prediction Center reported a weekly Niño-3.4 index of +0.7 degrees Celsius, with Niño-4 also at +0.7 and Niño-1+2 at +2.1. Those readings help forecasters decide when the Pacific has warmed enough to classify the pattern as El Niño.
How did it develop?
NOAA says the warming built over several months. Above-average sea-surface temperatures first appeared in the far eastern equatorial Pacific in early February. By mid-April, the warmer water had expanded across the central and eastern Pacific. On June 11, NOAA said El Niño conditions were present.
How strong could it get?
NOAA’s forecast points to more warming ahead. The Climate Prediction Center says its model guidance, including the North American Multi-Model Ensemble and the NCEP CFSv2 model, favors El Niño intensifying into winter 2026-27.
NOAA also says there is a 63% chance of a very strong El Niño during November-January. The agency said that level could rank among the largest events in the historical record going back to 1950. Like all seasonal forecasts, that outlook can change as ocean and atmosphere conditions shift.
Why does it matter?
El Niño can shift storm tracks and change temperature and rainfall patterns. NOAA uses the pattern in seasonal outlooks because it can help forecasters get a better read on months ahead, even though exact local impacts still vary by region.
NOAA’s Ocean Service says some U.S. coastal communities could see more high-tide flooding during El Niño. That does not mean every place will have problems, but it does mean coastal residents and local officials often pay closer attention to flood planning when the pattern forms.
For now, NOAA’s message is straightforward: El Niño has formed, and forecasters expect it to strengthen as winter approaches.
