Daniel Swain in WIRED: How a ‘Heat Dome’ Forms—and Why This One Is So Perilous

A massive, intense heat wave is settling over the continental US. The ravages of the COVID pandemic are going to make it all the more deadly.  A heat dome “is really just sort of a colloquial term for a persistent and/or strong high-pressure system that occurs during the warm season, with the end result being a lot of heat,” says climate scientist Daniel Swain of UCLA’s Institute of the Environment and Sustainability. “So after a certain point, once it’s been hot enough for long enough, it becomes even easier to get even hotter,” says Swain. “And so that’s why these things can often be really persistent because once they’ve been around for a little while, they start to feed off of themselves.”