Record-smashing heat spreads: ‘Basically the entire US is going to be hot’

After breaking March heat records in 14 states and the entire United States, the gigantic dome of heat blanketing the Southwest is moving eastward and could end up being one of the most widespread heat waves in American history, meteorologists and weather historians said.

And it’s not going to go away for a while, maybe not until the middle of next week, early April, said meteorologist Gregg Gallina of the National Weather Service’s Weather Prediction Center.

“Basically the whole United States is going to be hot,” Gallina said Monday. “The area of ​​record temperatures is extremely large. That’s what’s really weird.”

This heat dome — in which high pressure acts like a pot lid trapping warm air above a region — will leave Flagstaff, Arizona, with 11 or 12 consecutive days of temperatures above the city’s previous March record, said meteorologist Jeff Masters of Yale Climate Connections.

Gallina said the dome’s eastward movement would bring temperatures into the 90s Fahrenheit (mid 30s Celsius) by Wednesday over the southern and central Plains. Between a quarter and a third of the continent’s 48 states will flirt with March records, Gallina said.

The physical size of this heat wave likely dwarfs two other historic heat waves — one in 2012 in the Upper Midwest and Northeast and another in 2021 in the Pacific Northwest — according to weather historian Chris Burt, author of the book “Extreme Weather.” It may not be as large as the 1936 Dust Bowl heat waves, but it was a series of heat waves over two months over the summer, not a single major event like today, Burt said.

The 2021 Dust Bowl and heat wave were more intense, with higher temperatures hurting people more because they fell in June and July, Gallina said.

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

Four locations in Arizona and California reached 112 degrees (44.4 degrees Celsius) on Friday, according to the weather service. Not only did it break 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 states in April.

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

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

The National Center for Environmental Information recorded at least 479 weather stations, breaking records for the month of March, from Wednesday to Saturday, based on its network of stations. Herrera, who analyzed a larger data set, said the real figure is likely higher. Another 1,472 daily records – easier to break – were broken at the same time, the center said.

What’s happening is that the jet stream — which moves weather systems from west to east — is stuck as far west as the storms that douse Hawaii, where people witness torrential rains and flooding, Masters and Gallina said.

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

The thermal dome will move forward by the end of next week, Masters said: “We just have to give it time.”

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