Since last weekend, thousands of citizens in the center United State They face the devastation left in their wake by a swarm of tornadoes that, according to experts, are “extraordinary” for this time of year.
The most destructive tornadoes—originating from giant cells or broad thunderstorms—usually occur in the spring or early summer.
Look: “My husband cut my hand with an axe.”
But between Friday night and Saturday morning, many of these phenomena were recorded in a row of six states located in the central west and south of the country.
Staff from the National Weather Service (SNM) in Louisville commented that it’s still too early to know the exact number of storms that have arisen over the past few days.
But, at least in Kentucky, the hardest-hit state, there is data from a giant cell that originated in Arkansas at about 8:30 p.m. (CT) on the same Friday.
This atmospheric event traveled about 482 kilometers for about six hours. According to Ron Steve, a meteorologist with the Weather Prediction Agency, at least one tornado from this storm has traveled 262 kilometers.
SNM notes on its website that tornadoes usually travel only “a few kilometres.”
Although it left Arkansas and made its way to central Kentucky, this supercell passed through Missouri and Tennessee. That is why some media and scholars call it the “Quadruple State” (four states) hurricane.
“We’ve had what are called super thunderstorms. Basically, they have their own circulation and are able to sustain themselves for several hours. But these were some of the longest supercells I’ve ever seen,” Steve told BBC Mundo.
Meanwhile, fellow meteorologist and journalist Ben Hinn noted, in a blog written for Yale University, that the Quad State is one of the deadliest cyclonic storms ever seen.
Jeff Masters, a scientist who worked for the National Oceanic and Atmospheric Administration (NOAA) compared the weekend’s events to the Tri-State Tornado, which occurred in 1925, which was the longest-recording hurricane in history. from the United States.
“Last night was one of the most shocking weather events of my forty-year career as a meteorologist – a violent hurricane (in December!),” Masters wrote on his Twitter account.
Hen said the Tri-State tornado traveled 280 kilometers between Missouri, Illinois and Indiana.
Steve added that the intensity of the hurricane generated by the supercell was 3 on the Fujita scale, which means winds are between 254 kilometers and 331 kilometers per hour.
In Kentucky alone, authorities reported 64 deaths in the weekend’s events, at least through Monday.
So what happened during December to create a natural event of this magnitude?
The temperature in the Gulf of Mexico
It will take time to explain exactly why this supercell is formed, as it will require an in-depth analysis of the data.
But University of Wisconsin professor of atmospheric sciences, Angel Adams-Coralisa, told BBC Mundo that one of the key factors could be how hurricanes form in the central US.
In the central part of the country, sometimes known as Hurricane Alley, warm, moist air carried from the Gulf of Mexico meets cold air from the north. When there are also strong winds moving in different directions, thunderstorms or giant cells form from which tornadoes originate.
Adames-Corraliza said this was “common” in December. However, what is “extraordinary” and which may influence the generation of a phenomenon such as the Quad-State is the increase in the temperature currently recorded in the Gulf of Mexico.
“We’re talking about air coming in from the Gulf of Mexico that’s much warmer and wetter than we see at this time of year or at least that moist, warm air is being transported for longer distances than it’s usually transported,” Held.
Temperatures exceed 26 degrees Celsius in most parts of the Gulf of Mexico today. “The weather at this time of year is usually 24 degrees Celsius or less,” the professor commented.
Does climate change have an effect?
Although it cannot be suggested that climate change is responsible for the event, Adames-Corraliza said, it could have an impact due to its role in increasing temperatures.
However, there is no consensus among the scientific community about its effects on hurricanes, said Harold Brooks, a scientist at NOAA.
He told BBC News: “There is absolutely no consensus, as is the case with increased heat waves or torrential rains.”
He added that wind speed and atmospheric energy are the main drivers of hurricanes, but the evidence for how they change with warmer weather is not conclusive.
In 2018, the Intergovernmental Panel on Climate Change noted that some of the weather conditions that lead to a hurricane, such as instability, could be increased by higher temperatures and humidity.
US President Joe Biden said, although there was no consensus, that he would order an investigation with the US Environmental Protection Agency into the disaster.