(AP) – Subsequent to obliterating March temperature records across 14 states and the entirety of the U.S., the colossal heat dome that has scorched the Southwest is migrating eastward and could evolve into one of the most extensive heat waves in American history, according to meteorologists and climatological historians.
This oppressive heat is anticipated to persist for a considerable duration, potentially extending into the middle of the following week as April commences, stated meteorologist Gregg Gallina from the National Weather Service’s Weather Prediction Center.
“In essence, the entire United States will experience elevated temperatures,” Gallina commented on Monday. “The magnitude of the area affected by record-breaking warmth is exceptionally vast, which is truly an unusual characteristic.”
This phenomenon, where a high-pressure system functions like a lid on a pot, trapping warm air above a specific region, will result in Flagstaff, Arizona, enduring 11 or 12 consecutive days with temperatures surpassing the city’s previous March benchmark, observed meteorologist Jeff Masters of Yale Climate Connections.
Gallina elaborated that the dome’s eastward progression will bring temperatures in the 90s Fahrenheit (mid-30s Celsius) by Wednesday to the southern and central plains. He indicated that between one-quarter and one-third of the 48 contiguous states will be nearing March record highs.
The geographical expanse covered by this heat wave likely eclipses that of two other significant historical events: one in 2012 affecting the Upper Midwest and Northeast, and another in 2021 impacting the Pacific Northwest, according to weather historian Chris Burt, author of the publication “Extreme Weather.”
While it might not match the scale of the Dust Bowl heat waves of 1936, Burt clarified that those were a series of occurrences spread over two summer months, rather than a single, large-scale event as seen currently.
Both the Dust Bowl heat waves and the 2021 event exhibited greater intensity, with higher temperatures that posed more severe health risks due to their occurrence in June and July, Gallina explained.
An additional mitigating factor for those enduring this heat wave is the lower humidity level compared to what would be experienced if similar temperatures arose during the summer months, Gallina noted.
On Friday, four locations in Arizona and California registered temperatures of 112 degrees Fahrenheit (44.4 degrees Celsius), as reported by the Weather Service.
This not only shattered the record for the hottest March day in the continental United States by 4 degrees Fahrenheit (2 degrees Celsius), but it also fell just 1 degree shy of the highest temperature recorded in the Lower 48 states during April.
Climatologist and weather historian Maximiliano Herrera, a tracker of global weather records, has compiled a roster of 14 states that have set their hottest March day on record since the onset of this heat dome: California, Arizona, Nevada, Kansas, New Mexico, Nebraska, Utah, South Dakota, Missouri, Iowa, Colorado, Wyoming, Minnesota, and Idaho.
“In Mexico, even May records were obliterated, with March records being broken by as much as 14 degrees Fahrenheit, far exceeding temperatures recorded in July 1936, March 1907, or June 2021,” Herrera conveyed in an electronic message.
The National Center for Environmental Information documented a minimum of 479 weather stations breaking March records between Wednesday and Saturday, based on its observational network. Herrera, who undertook an analysis of a more extensive dataset, believes the actual number is likely higher.
An additional 1,472 daily records – which are generally more susceptible to being surpassed – were also broken during the same period, the center stated.
The underlying cause is an atmospheric phenomenon where the jet stream, responsible for steering weather systems from west to east, is largely stationary in its westward extent, similar to the conditions causing the storms currently drenching Hawaii with torrential rainfall and flooding, according to Masters and Gallina.
On Friday, an international consortium of climate scientists known as World Weather Attribution concluded that the record-breaking heat was “virtually impossible” to attribute solely to natural variability and was 800 times more probable due to climate change resulting from the combustion of fossil fuels.
The cumulative effect of these activities has elevated the temperature by at least 4.7 degrees Fahrenheit (2.6 degrees Celsius), according to report co-author Clair Barnes, a scientist at Imperial College London affiliated with the group.
The heat dome is expected to dissipate by the end of next week, Masters stated, adding, “We simply need to allow it time.”
