'Like Grilled Cheese in a Pan': Heat Dome Settles Over Western US

A bubble of  hot, stagnant air has settled over the western US. It's bringing record-breaking heat that's likely to last through the weekend.  

Temperatures under the “heat dome” have peaked at 20-25 degrees above average for large portions of California, Nevada, Arizona, and Utah. The heat has even extended as far east as Texas. Temps moved over 110° Fahrenheit (°F) in Las Vegas and Phoenix on Thursday. Through the weekend, 19 million people will remain under heat advisories.

What's the culprit? A high pressure system that’s camped over the region. It's acting like a trap for hot air. 

National Weather Service meteorologist Alex Lamers compared it to making grilled cheese in a pan with a lid on it. “It melts the cheese faster because the lid helps trap the heat and makes it a little bit warmer," he told NPR. 

Meteorologists predict that heat domes like the one scorching the US will become more common. Climate change is raising temperatures and altering air currents worldwide. On Wednesday, the UN issued a dire warning. It said that the past year was the hottest in recorded history. It also predicted our planet is now 80% likely in the next five years to surpass the 1.5° Celsius (2.7°F) warming danger mark set at the 2015 Paris Accords.

"We need an exit ramp off the highway to climate hell," UN Secretary-General António Guterres said. "The battle for 1.5 degrees will be won or lost in the 2020s."   

Reflect: How have extreme weather events affected your life or community?