El Niño may strengthen to 'super' levels and affect Arizona

Forecasters say La Niña has ended and there is an increasing chance of a strong — possibly very strong — El Niño that could influence Arizona's precipitation and temperatures.

Sea surface temperatures in the equatorial Pacific have returned toward normal, marking an end to the recent La Niña phase. Forecasters, including the National Weather Service, report rising odds that El Niño will develop, with a notable chance it could be strong to very strong. Regional scientists and meteorologists say a stronger El Niño would raise the probability of active winter weather and higher precipitation for parts of the Southwest, while uncertainty remains about exact outcomes. Key facts: - La Niña has ended and Pacific sea surface temperatures returned to near normal, according to forecasters. - The National Weather Service reported a 61% chance of El Niño developing as early as June and about a 25% chance sea surface temperatures could reach roughly 2°C above normal. - NOAA and regional meteorologists say stronger El Niño events are more likely to bring above-average precipitation to parts of the Southwest. - Scientists note uncertainty about how climate change may alter ENSO behavior, and the Climate Prediction Center adopted the Relative Oceanic Niño Index this year to account for warming trends. Summary: A strong or very strong El Niño could increase the likelihood of wetter and somewhat cooler conditions for Arizona into the coming winter and into 2027, though impacts are not guaranteed. Undetermined at this time.