WASHINGTON, July 7 (San Diego News Online) — NOAA forecasters say El Niño conditions are now present in the tropical Pacific and are expected to strengthen into the Northern Hemisphere winter of 2026-27.
That matters because El Niño is one phase of the El Niño-Southern Oscillation, or ENSO, a natural climate pattern that can shift weather patterns far beyond the Pacific Ocean. For people in the U.S., the most practical takeaway is to keep an eye on NOAA seasonal outlooks, especially if you live in a place where winter weather, drought, or coastal flooding can be sensitive to Pacific conditions.
What NOAA says now
The Climate Prediction Center, part of NOAA’s National Weather Service, issued an El Niño Advisory on June 11 and said El Niño conditions developed over the previous month. In its diagnostic discussion, the center said above-average sea surface temperatures covered the central to eastern equatorial Pacific Ocean.
NOAA said its latest weekly Niño-3.4 index was +0.7 degrees Celsius, with the Niño-4 index also at +0.7 degrees Celsius and the Niño-1+2 index at +2.1 degrees Celsius. Those values are used to track how warm the equatorial Pacific has become.
The forecast center said model guidance, including the North American Multi-Model Ensemble and NOAA’s CFSv2 model, points to El Niño strengthening through winter 2026-27.
NOAA also said there is a 63% chance of a very strong El Niño during November-January, which it said could place the event among the largest in the historical record going back to 1950.
What is El Niño?
El Niño is the warm phase of ENSO. It happens when parts of the central and eastern tropical Pacific become warmer than average for an extended period.
That warming can change winds, storm tracks, rainfall, and temperature patterns around the globe. NOAA says El Niño is identified by several signs, including warmer-than-average water in the equatorial Pacific and a shift in the ocean-atmosphere pattern there.
It is not a local storm and it is not a short-term weather system. It is a climate signal that can shape the season ahead.
Why the Pacific matters to the U.S.
El Niño does not affect every place the same way. NOAA says its impacts can vary by region and by event strength.
In the U.S., El Niño often raises the odds of a different winter pattern than the one seen during neutral conditions. That can include changes in temperature and precipitation, though NOAA stresses that local weather still depends on many other factors.
NOAA’s Ocean Service says an El Niño can also contribute to high tide flooding in some U.S. locations. That is a concern for coastal communities because even minor flooding can happen more often when tides are already high and weather conditions add extra water.
How fast is this developing?
NOAA’s technical bulletin says the first signs of above-average sea surface temperatures appeared in the far eastern equatorial Pacific in early February 2026. By mid-April, NOAA said the warmer water had expanded across the central to eastern Pacific.
An ENSO forecast page from the International Research Institute at Columbia University also says El Niño conditions are strengthening across the tropical Pacific. That page said the weekly Niño 3.4 index was +1.7 degrees Celsius on June 17 and expected the event to continue intensifying.
What should people watch for?
For most people, the best next step is simple: follow NOAA’s seasonal outlooks rather than assuming a single El Niño forecast tells the whole story.
If you live in a coastal area, watch for flood advisories and local high-tide flooding guidance as winter approaches. If you are planning for travel, agriculture, or emergency preparedness, check updates from NOAA and your local weather office, since the effects of El Niño can vary a lot by region.
The bottom line is that NOAA says El Niño is already underway and likely to grow stronger into winter 2026-27. The exact impacts will depend on how strong it becomes and how the atmosphere responds, but forecasters say the Pacific has clearly shifted into an El Niño pattern.