Tornadoes in USA: crushed by the storm – panorama

“Then we felt weird,” says Kyanna Parsons-Perez. “There was a lot of pressure on my ears and suddenly the whole building was shaking, back and forth, and then – boom – everything collapsed.” Kyanna Parsons-Perez tells CNN her story over the phone, her voice trembles, the near-death experience has left its mark. The American is one of 40 people who pulled rescue workers from the rubble of a destroyed candle factory in Mayfield, Kentucky. About 110 people were in the building. “It would be a miracle if anyone is found alive here,” said Governor Andy Beshear. And when you see the drone footage that CNN has been circling the scene of the accident, you understand what he means. Wrecked cars. Scrap metal. Crumpled steel. A field of rubble, crushed by the storm.

Several tornadoes wreaked havoc in the United States over the weekend. CNN reported more than 30 tornadoes in six states, including Kentucky and Mississippi, Missouri, Tennessee, Illinois and Arkansas. the New York Times according to at least 70 people have died in Kentucky alone.

The storm hit Kentucky particularly hard. Saturday night was “one of the toughest” in the state’s history, said Governor Beshear. The storms left a trail of devastation. “Everything in their path is gone. Homes, businesses, government buildings – just gone.” When the governor spoke about his father’s hometown, Dawson Springs, his voice almost failed. US President Joe Biden was dismayed by the destruction and promised help to the affected states on Saturday.

Usually, tornado season in the United States is closer to March through June, when conditions in the atmosphere are most common for tornado. It is unusual for such a swarm of tornados to occur in December. The final assessment by the authorities is still pending, but US meteorologists suspect that among the tornadoes were those in the highest categories EF3, EF4 or even EF5 of the “Enhanced Fujita Scale” used for tornadoes.

Does climate change play a role?

One of the highest categories is likely to belong in particular to the windpants, which Mayfield in Kentucky destroyed, where it also hit the candle factory. Debris was hurled eleven kilometers into the air. If the first observations are confirmed, this tornado raced over a distance of more than 370 kilometers through four states, that would be the longest tornado corridor since records began.

It is still unclear how climate change will affect the frequency and intensity of tornadoes. It is true that the warmer air, which can absorb more moisture, provides more and more of the energy that drives such events. On the other hand, the warming could lead to a decrease in the so-called wind shear, i.e. different wind directions in higher and lower air layers, without which tornadoes cannot form. A clear increase or decrease in extreme tornadoes has not yet been observed in the USA, although this could also be due to the fact that they are difficult to record systematically. An EF5 tornado has not been observed in the US for eight years, the longest such void since records began in the 1950s. However, there is evidence that the incidence of tornadoes in the now affected region around the Mississippi Valley increasing.

In this case, all the prerequisites for violent tornadoes came together: The large temperature difference between the north and the southeast of the USA, with minus degrees in Minnesota and more than 25 degrees Celsius in Tennessee, produced a front where warm and cold air masses clashed with force. There was also a significant wind shear. Also the climate phenomenon that has dominated the world since autumn La Niña could have promoted this location, the counterpart too El Niño. In La Niña-Years of the trade winds drive warm water increasingly over the Pacific to the west; In the USA, this makes winter colder in the north and warmer in the south. In La NiñaYears ago, winter tornadoes appear to be more common in the southeastern United States, as researchers did a few years ago Nature Geoscience reported.