As spring struggles to emerge, a formidable heat dome that shattered March temperature records across 14 states—and the nation at large—is gradually shifting eastward. Experts suggest this might become one of the most widespread heat waves in U.S. history.

According to meteorologist Gregg Gallina from the National Weather Service’s Weather Prediction Center, this oppressive heat isn’t expected to dissipate anytime soon. “It might linger until mid-next week as April begins,” he remarked.

Gallina emphasized the unusual breadth of this heat wave, stating, “Essentially, the entire U.S. is going to experience higher than normal temperatures. The expanse of record-setting temperatures is what’s truly astonishing.”

Characterized by high pressure that traps hot air, this heat dome is subjecting Flagstaff, Arizona, to an unprecedented streak of 11 or 12 consecutive days exceeding the city’s previous March temperature records, according to Jeff Masters from Yale Climate Connections.

As the heat dome migrates east, Gallina predicts that temperatures will soar into the 90s Fahrenheit (mid-30s Celsius) by Wednesday across the southern and central plains. Up to a third of the continental U.S. may flirt with March records.

Weather historian Chris Burt, author of “Extreme Weather,” notes that the sheer size of this heat wave likely surpasses historic events, such as the 2012 heat wave in the Upper Midwest and Northeast and the 2021 event in the Pacific Northwest. While it may not match the Dust Bowl heat waves of 1936, those were multiple, smaller events across summer months, whereas this is a single, massive occurrence.

Both the Dust Bowl and the 2021 heat wave were more intense, with higher temperatures that hurt people more because they fell in June and July, Gallina said.

Another saving grace for people in this heat wave is that it’s not as humid as it would be if the temperatures rose in the summer, Gallina said.

On Friday, four places in Arizona and California hit 112 degrees (44.4 degrees Celsius), according to the Weather Service. Not only did that smash the record for the hottest March day in the continental United States by 4 degrees (2 degrees Celsius), but it was only 1 degree shy of the hottest day recorded in the Lower 48 in April.

Climatologist and weather historian Maximiliano Herrera, who tracks global weather records, compiled a list of 14 states that have notched their hottest March day on record since this heat dome started: California, Arizona, Nevada, Kansas, New Mexico, Nebraska, Utah, South Dakota, Missouri, Iowa, Colorado, Wyoming, Minnesota and Idaho.

“In Mexico, even May records were trashed with March records broken by as much as 14 (degrees Fahrenheit), far more than July 1936, March 1907 or June 2021,” Herrera wrote in an email.

The National Center for Environmental Information registered at least 479 weather stations breaking records for March from Wednesday through Saturday, based on its network of stations. Herrera, who analyzed a broader set of data, said the true number is likely higher. Another 1,472 daily records — which are easier to break — were shattered at the same time, the center said.

What’s happening is the jet stream — which moves weather systems from west to east — is pretty much stuck as far westward as the storms dousing Hawaii, where people are seeing torrential rains and flooding, Masters and Gallina said.

On Friday, a group of international climate scientists called World Weather Attribution determined that the record heat was “virtually impossible” and 800 times more likely because of climate change from the burning of coal, oil and natural gas. The result of those activities added at least 4.7 degrees (2.6 degrees Celsius) to the heat, said report co-author Clair Barnes, an Imperial College of London scientist with the group.

The heat dome will move on by late next week, Masters said: “We just have to give it time.”

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