NOAA forecasters confirmed an El Niño developed in the tropical Pacific in early June 2026 and said the event is likely to strengthen through autumn. The US National Weather Service issued an El Niño advisory and the agency reported a 63 percent chance sea surface temperatures will exceed 2.0°C in the Niño monitoring region during November to January, a threshold NOAA classifies as very strong.
The Climate Prediction Center is using the new Relative Oceanic Niño Index for monitoring, a method NOAA adopted in February 2026 to make ENSO tracking more responsive. The agency said improved monitoring helps emergency managers and the public prepare for seasonal shifts tied to the event.
The United Nations warned in June 2026 that the developing El Niño could become one of the strongest in decades, raising the risk of extreme weather worldwide. NOAA and other agencies stressed that each El Niño has a unique imprint and that other climate drivers will modulate outcomes.
Impacts For The Northwest And Marine Systems
Regional outlooks from NOAA and Climate.gov indicate Idaho Oregon and Washington face a higher probability of warmer drier fall and winter conditions, while much of Alaska is more likely to see a wetter fall and a warmer drier winter. NOAA seasonal maps show elevated chances of below normal precipitation across parts of the Northwest and above normal precipitation for much of Alaska.
Forecasters say the winter pattern linked to El Niño usually shifts the North Pacific jet stream southward, steering storms into the southern US while reducing precipitation in the northern Rockies and Pacific Northwest. In the Northwest this often means more precipitation falls as rain rather than snow, lowering snowpack and summer runoff.
NOAA and Climate.gov warned of cascading risks. Reduced runoff and warmer winters can worsen drought and raise wildfire risk. Strong El Niño events have coincided with marine heatwaves that displace cold water species, disrupt fisheries, and foster harmful algal blooms. The 1983 El Niño and the marine heatwave of 2023 were cited as examples of ecological and fishery impacts.
Coastal effects include higher sea levels larger waves and increased shoreline erosion during strong events, and NOAA graphics show rising high tide flood days in the Northwest beyond sea level rise alone. Scientists note climate change could amplify some El Niño impacts and that the IPCC assessed precipitation variance tied to ENSO is very likely to increase, but models disagree on how ENSO frequency or strength will change long term.
Forecasters emphasized that El Niño raises probabilities rather than guarantees. Local weather will also depend on other climate patterns and short term atmospheric variability, so communities and resource managers should use seasonal outlooks to guide preparedness.
