El Nino Set to Be the Strongest in Living Memory, Met Office Warns

Scientists declare an El Nino once sea surface temperatures in a key area of the Pacific run 0.5C above average. They are already well over 2C above normal, and the latest Met Office forecasts suggest the anomaly could exceed 3C — unprecedented in records going back to 1950, and probably the strongest since the 19th century. Water 8C above normal at a depth of 100m could supercharge it further.

What El Nino means for the UK

El Nino recurs every two to seven years, when Pacific trade winds weaken and warm water spreads east, releasing heat into the atmosphere. There is growing evidence those shifts have begun, with below-average monsoon rains in India and suppressed Atlantic hurricane activity. Britain, the Met Office says, could face a greater risk of a wet, stormy autumn — after a summer of amber health alerts and advice on how to keep cool. Nearer term, models still show hot spells returning.

We should be clear that this is an unprecedented event. I have never seen an El Nino signal this intense in our forecasts.

Prof Adam Scaife, head of long-range forecasting at the Met Office

The event is still months from its peak. "We have many months to go while this event continues to develop," said Dr Zeke Hausfather, a climate scientist at Berkeley Earth, "and that's one of the reasons that we have increased confidence that this will be a record-setting event."