Massive Heat Dome Moving East Could Create Historic U.S. Heat Wave

A massive heat dome that shattered March temperature records in 14 states is moving eastward and could become one of the most expansive heat waves in American history. The extreme temperatures are expected to continue through at least the middle of next week, with nearly the entire continental U.S. experiencing unusually hot weather.

A massive heat dome that destroyed March temperature records across 14 states and nationwide is now shifting eastward, potentially creating one of the most widespread heat waves in U.S. history, according to meteorologists and weather historians.

The extreme temperatures aren’t expected to subside anytime soon, possibly lasting until the middle of next week as April begins, according to meteorologist Gregg Gallina from the National Weather Service’s Weather Prediction Center.

“Basically the entire U.S. is going to be hot,” Gallina stated Monday. “The area of record temperatures is extremely large. That’s the thing that’s really bizarre.”

This weather phenomenon — where high atmospheric pressure acts like a lid, trapping scorching air over vast regions — will result in Flagstaff, Arizona experiencing 11 or 12 consecutive days with temperatures exceeding the city’s previous March records, according to meteorologist Jeff Masters from Yale Climate Connections.

As the dome moves eastward, Gallina predicts temperatures will reach the 90s Fahrenheit by Wednesday across southern and central plains states. Between one-quarter and one-third of the lower 48 states will be challenging March temperature records, Gallina explained.

The geographic scope of this heat event likely surpasses two other significant heat waves — the 2012 event in the Upper Midwest and Northeast, and the 2021 Pacific Northwest heat wave — according to weather historian Chris Burt, who authored “Extreme Weather.” While it may not match the size of the 1936 Dust Bowl heat waves, Burt noted that event consisted of multiple heat waves over two summer months, unlike the current single massive occurrence.

However, both the Dust Bowl and 2021 events produced more dangerous conditions with higher temperatures that caused greater harm because they occurred during June and July, Gallina noted.

One positive aspect of the current heat wave is the lower humidity levels compared to what would occur if these temperatures hit during summer months, Gallina added.

Last Friday, four locations in Arizona and California recorded 112 degrees Fahrenheit, according to the Weather Service. This temperature not only broke the previous continental U.S. March record by 4 degrees, but came within just 1 degree of the hottest April temperature ever recorded in the lower 48 states.

Weather historian and climatologist Maximiliano Herrera, who monitors global temperature records, documented 14 states that have set new March temperature records 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 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 recorded at least 479 weather stations setting new March records between Wednesday and Saturday within its monitoring network. Herrera, analyzing broader data sets, believes the actual number is significantly higher. Additionally, 1,472 daily temperature records were broken during the same period, the center reported.

The cause involves the jet stream — which typically moves weather systems from west to east — becoming stuck as far west as the storms currently flooding Hawaii with torrential rains, Masters and Gallina explained.

Last Friday, international climate scientists from World Weather Attribution concluded that such record heat was “virtually impossible” without climate change caused by burning fossil fuels, making it 800 times more probable. These human activities contributed at least 4.7 degrees to the extreme temperatures, according to report co-author Clair Barnes, a scientist at Imperial College of London.

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