There is much speculation about how the developing El Niño will affect weather patterns in the UK and around the world.
It is still forming at present, and it won’t be fully developed until the end of the year, so we shouldn’t anticipate any immediate effects, especially on the UK summer. But what can we expect from this pattern of climate variability in the longer term?
There are three key areas to look for and we will look at each of these in turn:
- The heat coming from the tropical Pacific and its impact on the atmosphere potentially raising the average global temperature; very likely to a new global record this year or next.
- There are anticipated impacts in regions adjacent to the Pacific; notably southeast Asia and eastern Australia, where we could see drier than average conditions which could exacerbate wildfire risk.
- There is a known association between El Niño and a colder than average end to winter in northwest Europe.
Global temperature
The last major El Niño spanned 2015 and 2016, and the second year of the event remains the hottest year on record. Jeff Knight is the Met Office’s manager of Climate Variability Modelling. He said: “A typical El Niño temporarily adds about 0.2C to average global temperature.
“This increase is dwarfed by the 1.2C that we have seen from climate change since the Industrial Revolution but added to that human-induced warming a new global temperature record is likely before the end of next year.”
Regional impacts
El Niño brings increased risk of drought to South-East Asia, India, North-Eastern Australia and parts of the Amazon and southern Africa and increased risk of cold conditions to northern Europe in winter. We will be looking carefully at these regions with our colleagues at other national meteorological services as El Niño develops and updated forecasts become available.
Potential impacts on UK winter
Although El Niño has a major influence on altering global weather patterns, it effects on northwest Europe and the UK are often tempered by other more home-grown weather influences.
Jeff Knight added: “The UK is a long way from the tropical Pacific and although El Niño can have an influence on winter in the UK, it is only one of a number of factors that forecasters will have to take into account when assessing the winter outlook.”
You can find out more about El Niño in our explainer video: El Nino – What is it?
As we have explained above, the typical historical impacts of El Niño can be calculated: however, individual events can differ in detail, such as timing and magnitude. Moreover, El Niño constitutes just one (albeit very important) influence on climate variability.
For this reason, the typical response to El Niño should not be seen as inevitable. Rather, El Niño events should be regarded as shifting the odds in favour of the typical response which may, for example, increase the risk of heavy rainfall and consequent damage in a particular region or season of interest.
