What is the ‘African plume’ that could bring 35C heatwave conditions to UK?

African plumes, the heatwave phenomenon that could sizzle the UK, can make temperatures soar this June and July

England saw its joint-hottest summer ever recorded in 2022 (AFP/Getty Images)

The UK is bracing itself for a scorching summer as meteorologists have predicted the arrival of the much-discussed “African plumes” later this month which can make temperatures soar to 35C.

In a widely reported forecast, Exacta Weather said African plumes are likely to sweep across Europe between June and September.

The weather phenomenon, characterised by a mass of hot air originating from the Sahara desert, have the potential to bring multiple heatwaves.

While such a scenario may be unprecedented, experts agree it is not impossible, given recent warming climate trends.

On Sunday, the UK witnessed temperatures above 20C in several areas across England and Wales, making it the hottest day recorded this year so far.

The coming days are set to get warmer with “above average” temperatures expected by the end of May.

As the UK eagerly awaits the summer heat, there is fear that the conditions can get worse again this year, with heatwave-like conditions stemming from the arrival of the anticipated African plumes.

Here’s what exactly an African plume is and how hot it can get.

What is an African plume?

An African plume is a weather phenomenon in which hot air masses from the Sahara desert in Africa are transported northward towards Europe, including the UK.

This plume of hot air carries with it high temperatures and dry conditions, leading to exceptionally warm weather.

During an African plume event, southerly or southeasterly winds carry the hot and dry air across the Mediterranean Sea towards the British Isles. As the air mass moves over the warm waters of the Mediterranean, it absorbs heat and moisture, further intensifying its warmth and humidity.

This process creates a distinct narrow band of hot air, resembling a feather-like structure on weather maps.

How hot will it get when African plumes arrive?

When an African plume reaches the UK, it brings a period of unusually hot temperatures, often exceeding 30C.

These high temperatures can persist for several days or even weeks, resulting in heatwave conditions.

However, the intensity and duration of the heatwave can vary from year to year, depending on atmospheric conditions.

James Madden of Exacta Weather told The Mirror that there are “some strong indicators” for a “warm to hot September this year” due to the African plumes.

“The peak of these heat surges in June and July could see maximum temperatures ranging in the low to mid-thirties, and the late summer/August heatwave could sign off summer 2023 with temperatures ranging a notch or two higher than this,” he was quoted as saying.

Is it connected to the climate crisis?

While weather patterns can be influenced by various factors, the increased occurrence of African plumes aligns with our warming climate, experts said.

According to Met Office meteorologist Honor Criswick, there is “a greater than normal chance” of heatwaves in the UK this summer, which is “consistent with our warming climate”.

However, she said that, “as always with a longer-range forecast, there is always some uncertainty”.

While one weather phenomenon alone does not guarantee a heatwave, with a warmed up world of 1.2C, such occurrences have become more frequent in recent years.

This year is particularly worrying, as the World Meteorological Organisation (WMO) said the El Niño weather phenomenon, associated with the warming of the oceans, is set to take over later this year.

“The development of an El Niño will most likely lead to a new spike in global heating and increase the chance of breaking temperature records,” WMO Secretary-General Petri Taalas said at the time of the warning.

The world is also expected to breach the 1.5C warming threshold, the agreed limit of the Paris Agreement, as early as within the next five years, warned the WMO.

The heatwaves experienced in 2022 already signalled the impact of the climate crisis, with England recording its joint-hottest summer on record.

The Met Office's chief scientist, Professor Stephen Belcher, described the 40C temperatures experienced last year as “virtually impossible without climate change”.