More than three-quarters of the United States is in the midst of a record-breaking heat wave.
The sweltering situation is caused by a phenomenon called a heat dome, during which hot, high-pressure air camps out over the continental United States. 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 UCLA climate scientist Daniel Swain to Wired’s Matt Simon.
Some regions have seen days on end of unusually high temperatures. Muskegon, Michigan, saw nine straight days with highs over 90-degree Fahrenheit, a new record. Likewise, Buffalo, New York, had eight straight days over 90 degrees, also a record there, according to Weather’s Jonathan Erdman.
Parts of California, Nevada and Arizona are under excessive heat warnings from the National Weather Service, and Phoenix, Arizona, has had ten straight days of over 110-degree weather. The National Weather Service in Phoenix expects that temperatures will remain above normal for the foreseeable future, reports Matthew Cappucci for the Washington Post.
This event is far from America’s first heat dome. In the last decade, heat domes were reported in 2011 and then every year since 2016. The years from 2016 to 2019 are also all in the top five hottest years on record, according to NOAA.
Wired reports that the dangers from high heat could compound with dangers from the COVID-19 pandemic, which is keeping people in homes that may not have air conditioning. Extreme heat caused the deaths of over 7,000 people between 1999 and 2010, according to the Centers for Disease Control and Prevention. The CDC has created specific guidelines for community cooling centers, which have the potential to become COVID-19 hotspots by bringing together many people in close proximity indoors.
https://www.smithsonianmag.com/smart-news/how-us-got-caught-under-heat-dome-180975294/