What could a 'super' El Niño mean for the Prairies? | CBC News

The much-talked-about El Niño continues to heat up in the Pacific Ocean.

"Every indicator has shown that this [El Niño-Southern Oscillation] is continuing to strengthen," said Lindsey Long, a meteorologist with the ENSO team at the Climate Prediction Center (CPC) in the U.S.

"We're getting [sea surface temperature] anomalies of up to 11 C, so those are extremely warm waters that are helping to fuel this."

El Niño is part of the El Niño-Southern Oscillation (ENSO) , which is a fluctuation between warmer sea surface temperature anomalies — El Niño — and colder anomalies — La Niña — in the equatorial region of the Pacific Ocean. 

During normal conditions, west-blowing trade winds push warm sea surface temperatures from South America toward Asia. However, those winds can break down or reverse direction, allowing that warm water to instead pool near South America.

This disrupts weather patterns around the world, including a stronger Pacific jet stream and an amplified polar jet stream over western Canada.

As of Sept. 14, a very strong El Niño was being observed in what's called the El Niño 3.4 region in the eastern equatorial Pacific, where average sea surface temperatures were 2 C warmer than normal.

Experts predict the current El Niño to peak during the late fall and winter months.

The last El Niño classified as very strong occurred during the 2015-16 winter. The Prairies also experienced a moderate El Niño during the 2023-24 season. Both brought warmer than normal temperatures to the Prairies.

Research scientist Bill Merryfield with Environment and Climate Change Canada says that could also be the case this winter.

"The odds are certainly tilted in that direction of having a relatively mild winter, possibly by a large margin," he said.

"Some of those temperature differences from normal during past very strong El Niños have been in the range of 5 or 6 degrees averaged over the winter, which is quite substantial.”