'Heat dome' expected to send temperatures soaring in France

The regions of Languedoc and Provence could have weekend highs of up to 41ºC

France convenes emergency meeting in anticipation of soaring temperatures. Bloomberg

The French government held a crisis meeting on Thursday to discuss measures to deal with a heatwave in which temperatures could climb beyond 41ºC this weekend.

After the intense heat and wildfires of 2022, Paris has been increasing hot-weather protection measures this summer.

Over the weekend, temperatures in the regions of Languedoc and Provence in the south could rise as high as 41ºC, said meteorologist Christelle Robert of Meteo France.

Forecasters expect the high temperatures to continue into early next week.

A “heat dome” trapping hot air arriving from the south is expected to form in the coming days.

Heat will spread into central and northern France as well, with temperatures of 35ºC forecast for Paris.

The mercury in thermometers will not begin to fall until “the middle or even the end of next week”, said Meteo France.

On Friday, an information hotline will be launched and public information messages broadcast on TV and radio, Prime Minister Elisabeth Borne's office said after the meeting attended by representatives from the interior, health, agriculture and transport ministries.

Seven of mainland France's 96 departments are already on alert for summer storms and intense heat, and another 12 will join them on Friday, mainly in the east and south of the country.

What is a heat dome?

A heat dome is a meteorological event characterised by a persistent high-pressure system that acts as a dome or barrier, trapping warm air in a region.

This phenomenon results from the confluence of several factors, leading to a steep rise in temperatures that can linger for days or even weeks.

At the heart of a heat dome is a high-pressure system in the upper atmosphere.

When this system forms, the air becomes denser and sinks, and as it descends, it compresses and warms up.

This high-pressure lid also blocks incoming weather systems, effectively preventing cooler air and disturbances from breaking through.

Consequently, the trapped warm air heats the ground below, which in turn warms the air above it even more, thereby strengthening the high-pressure system – a feedback loop that sustains and can even intensify the heat dome.

Several elements contribute to the formation and persistence of heat domes.

The jet stream, a band of strong, high-altitude winds, can play a role when it weakens or shifts, facilitating the build-up of warm air.

Climate patterns such as La Nina, which cools the Pacific Ocean, can also amplify these conditions.

Additionally, human-induced climate change, with its overarching warming effect, is believed to make such extreme heat events more frequent and intense.

The ramifications of a heat dome are manifold and severe. Areas under its grip can experience record-breaking temperatures, leading to heat-related illnesses and even fatalities, especially among vulnerable populations such the elderly or chronically ill.

The soaring heat can overload power grids, triggering power cuts, and the dry conditions increase the risk of wildfires. Moreover, the relentless heat can devastate agriculture, harming crops and livestock.

Cooler temperatures to hit the continent soon

Europe is expected to experience a respite from the current heatwave, with cooler temperatures expected by next weekend.

However, France and the Iberian Peninsula will continue to endure unusually high temperatures, reaching the upper 30s to lower 40s Celsius, before normalising.

Maxar Technologies. forecasts that Madrid will return to its typical temperatures by the week's end.

This summer has produced a range extreme weather events, from wildfires in Greece, Spain and Tenerife, to flash floods in Norway, Serbia and Germany.

Notably, Frankfurt in Germany experienced significant flooding after a storm that produced more than 25,000 lightning strikes in an hour – more than double the total observed throughout 2022.

Raging wildfires continue to alarm Tenerife

An uncontained wildfire has ravaged parts of the Spanish Canary island of Tenerife, burning hundreds of hectares and affecting about 8,000 residents through evacuations or confinement measures.

According to Regional President Fernando Clavijo, this is perhaps the most challenging fire the Canary Islands have encountered in the past 40 years.

The fire started on Tuesday night in the island's mountainous region, where the terrain makes it challenging for emergency services to access.

With the island's main town, Santa Cruz, 19kms away, the primary objective is to prevent the fire spreading to more densely populated areas.

Currently, six municipalities are under threat. Although the main tourist areas are unaffected, access to Teide National Park, a significant tourist attraction, has been restricted, with facilities and the local Astrophysics Institute evacuated.