https://www.wired.com/story/scientists-are-getting-better-at-predicting-killer-heat-waves/

The City of Lights could be the City of Lights Out tomorrow as temperatures approach a record of 107 degrees. And Paris isn’t the only place sweltering in this week’s heat. Cyclists in the Tour de France are wearing stretchy sacks of ice around their necks as they race toward the Alps, while commuters on the London Underground carry spare water bottles and Spanish firefighters battle wildfires—all thanks to torrid air from the Sahara that got trapped between storm systems over the Atlantic Ocean and Eastern Europe, forming a “heat dome” over the entire continent. It’s similar to the extreme heat that lingered over the eastern United States for a 12-day stretch in July, breaking records and warming the Potomac River to 94 degrees.

The ability to predict the next heat wave is a big deal to meteorologists. That’s because more warning means extra time to prepare cooling centers and swimming pools, shore up the electric grid, and pre-position supplies for heat-vulnerable populations and machines. As you might expect, climate change is making heat waves longer and more common. Scientists say that the number of heat waves in 50 major American cities has tripled since the 1960s. Last month was the hottest since record-keeping began 140 years ago.