“I have not seen an event like this developing in our forecasts before”, said Professor Adam Scaife, head of long-range forecasts at the Met Office.
He says the scale of the growing El Niño is unprecedented in modern climate records.
As it approaches its peak by the end of 2026, its influence around the world will grow with effects spreading across the globe.
Professor Scaife says forecasters “already see signals for increased rainfall and storminess in autumn here in the UK”, especially into November and December.
After a summer that looks set to be the UK’s hottest on record and with the drought conditions that continue to grip large swathes of the country, a wet autumn sounds like good news.
However, we know that climate change is making increasingly intense rainfall more likely, and so these storms and downpours will also bring the threat of flooding.
Strong winds could also cause damage, transport disruption and power cuts.
The winter of 2015 and 2016, which coincided with a very strong El Niño, brought a succession of major storms delivering what experts at the time described as the most extreme flooding on record.