Europe Braces for Next Heat Wave After Cool Start to August

(Bloomberg) — Europe’s next heat wave is already building over the Iberian peninsula, potentially testing more temperature records after an unseasonably cool start to August.

The cooler interlude will soon pass as a high-pressure system over Portugal and Spain marches east across the continent through mid-August, according to forecast models. Daytime highs could rise to 42C (108F) in southern Spain, with average temperatures climbing 10C above the norm, according to national forecaster AEMET.

That will bring “further heat wave risks, particularly across the west through August,” said Amy Hodgson, a meteorologist with Atmospheric G2.

Climate change is boosting the intensity and frequency of heat waves, threatening the health of millions of people and stressing power systems in Europe, the fastest-warming continent. Last week, Turkey recorded its highest ever temperature of 50.5C. That heat is also triggering extreme weather events, from wildfires to violent storms.

While the latest heat wave could weaken as it spreads east, unseasonably high temperatures are expected for the UK, France and Switzerland by the end of next week. London could see highs near 30C on Aug. 11, with Paris reaching 37C after that.

Parts of central and southeastern Europe will also be impacted, with highs forecast to reach 38C in Geneva and nearly 40C in Cyprus.

Before that transition, a swath of the continent from the UK in the northwest to Greece in the southeast will see average temperatures a few degrees below normal as August begins. A strong jet stream is also expected to drive a surge in wind generation across central and eastern regions, Hodgson said.

That output will fade as the high-pressure system establishes itself, bringing stronger solar generation through mid-August.

The hot, dry weather could also force Electricite de France to curb nuclear generation at reactors along the Rhone river as rising water temperatures compromise cooling operations.

“Further heat and little precipitation is expected across France through August, which would put further stress on river systems,” Hodgson with Atmospheric G2 said.

Storm Uncertainty

Confidence in longer-term forecast models covering the end of August is lower due to an expected increase in tropical storm activity in the north Atlantic, Hodgson said. The timing and position of those storms can power atmospheric changes that change the intensity and direction of the jet stream arriving in Europe.

Comparing the forecast conditions for late-August to those in previous years, however, MetDesk meteorologist Emma Patmore sees potential for a high-pressure system forming in northwest Europe with a low-pressure trough in the southeast. That could set the stage for a late-summer heat wave across the continent.

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