Strengthening El Nino likely to ‘rank among largest’ on record: US agency

WASHINGTON: The El Nino weather pattern picked up strength over the past month and is highly likely to “rank among the largest” ever recorded when it peaks between October and December, US forecasters said Thursday (Jul 9).

El Nino warms surface temperatures in the central and eastern equatorial Pacific Ocean, triggering worldwide changes in winds, atmospheric pressure and rainfall patterns, and pushing warmer overall global temperatures.

In its latest update, the US Climate Prediction Centre (CPC) said there is an 81 per cent chance of a “very strong” El Nino between October and December that would rank among the largest such events in the historic record going back to 1950.

“Very strong” is defined as being 2.0 degrees Celsius (3.6 degrees Fahrenheit) or more above an index value.  The CPC also put the odds at 97 per cent that the event will persist through early spring 2027.

That adds to a prediction made by Tim Stockdale, an El Nino expert of the European Centre for Medium-Range Weather Forecasts, who said this week it would be “a very, very big surprise” if the event failed to be a record-breaker.

El Ninos typically have knock-on effects globally, including drier conditions and drought in Australia, along with wetter winters in East Africa and the southern United States. 

Isla Simpson, a climate scientist at the US National Centre for Atmospheric Research, told AFP that “there’s quite a lot of evidence from our models that global warming increases the variance of El Nino, so you get bigger El Nino events and also bigger La Nina events.”

La Nina is the cooling phase of the El Nino-Southern Oscillation cycle.