El Nino to be biggest in over a century, Met Office says

Britain's Met Office predicted on Friday that this year's El Nino weather pattern will be the biggest in more than a century, with tropical eastern Pacific sea surface temperatures expected to peak at more than 3C above the baseline.

Adam Scaife, head of long-range forecasting at the Met Office, told the BBC: “We are expecting the biggest El Nino for over a century, peaking at something over three degrees -- that is unheard-of in modern climate records.” He called it “an unprecedented event” and said he had never seen an El Nino signal that intense in the agency's forecasts.

El Nino is declared when sea temperatures in the tropical eastern Pacific rise 0.5C above the baseline average. The pattern can trigger worldwide changes in winds, atmospheric pressure and rainfall patterns, and can raise global temperatures overall.

Scaife said the anomalous warmth was already “up to nearly two degrees” and would have particularly strong effects across the Tropics. He said the Met Office expected severe droughts in places such as South America and the West Pacific.

The Climate Brink dashboard put temperatures in the region at about 2.6C above a rolling 30-year average.

Scaife said the forecast involved long-term, persistent conditions rather than short-term weather, with possible effects on food and food security. He also said the pattern was expected to bring increased rainfall and storminess in the UK around November.