Global warming-fueled supercells crash south more often, study says

America will likely get a supercell that produces more powerful tornadoes and hail as the world warmsa new study warns that deadly storms will head east and strike more frequently in populous southern states such as Alabama, Mississippi and Tennessee.

supercell storm Ruined Rolling Fork, Mississippi A single event that is not linked to climate change. But it fits the predicted more dangerous pattern, including more nighttime strikes in southern regions that are more populous than storm-hit places in the 20th century, with poverty and fragile housing. And the season will start a month earlier than before.

research in Bulletin of the American Meteorological Society predicted a 6.6% increase in supercells nationwide, a 25.8% increase in area, with the strongest supercells twisting and tearing the land under scenarios of moderate levels of future warming by the end of the century. I’m here. However, in certain areas of the South, the rate of increase is much higher. This includes rolling forks, and the study authors predict that by 2100 there will be an increase of one supercell per year.

Supercells are nature’s ultimate storm, the so-called “finger of God” rampage, and the “primary source of severe tornadoes and hail,” says lead author and meteorologist at Northern Illinois University. and Walker Ashley, professor of disaster geography. Tall, anvil-shaped, sky-filled supercells A powerful rotating updraft It can be windy and last for hours.

created by supercell 2013 Moore, Oklahoma Tornado killed 51 people, 2011 Joplin, Missouri Tornado outbreak that killed 161 people 2011 super pandemic More than 320 people died in Alabama, Mississippi, Tennessee and the Mid-South.

The study used computer simulations to predict what would happen by the end of the century at various levels of global carbon pollution levels. But Ashley said it looks like a stormy future is already there.

“The data I have seen confirms that we are in this experiment. live in the present” Ashley said three days before the interview. EF-4 Tornado More than 20 people died in Mississippi on Friday. “What we see long-term is actually what’s happening now.”

Ashley et al. said that while the Mississippi tornado fits the predicted pattern, it is a single weather event, unlike many years of climate projections and large areas.

Ashley and study co-author Victor Genzini, another meteorology professor at Northern Illinois University and a longtime tornado expert, see another possible supercell explosion in the Mid-South on Friday. .

Previous studies have failed to predict supercells and tornadoes in future climate simulations. Because they are small events, especially tornadoes, and cannot be seen in global computer models. Ashley and Gensini used a small regional computer model and spent two years running simulations and processing the data to compensate for the lack of computational power.

Three scientists unrelated to the study said it made sense. He said it was a promising advance because it explicitly simulated storms, compared to previous studies examined.

The study shows a general increase in supercell numbers, but mostly large shifts in where and when they are hit. Generally on the east side of Interstate 35 through East Texas, Oklahoma, and Kansas, and less on the west side.

Moderate warming – less warming than the world is headed for based on current emissions – parts of eastern Mississippi and eastern Oklahoma, eastern Texas, Arkansas, Louisiana, Alabama and Tennessee Three more supercells are projected to occur every two years in the western part of the state, eastern Georgia. Get another supercell every other year.

A study of worst-case warming – more than the world is currently projecting – projected similar changes despite worsening supercells in eastern Oklahoma, Arkansas, and southern Missouri. I’m here.

Cities that should see more supercells as warming worsens include Dallas-Fort Worth, Little Rock, Memphis, Jackson, Tupelo, Birmingham and Nashville, Ashley said.

Moderate warming simulations project supercells to increase by 61% in March and 46% in April, while more severe warming scenarios see 119% in March and 82% in April. is predicted. There is a double-digit percentage point drop in June and July.

Over the Mid-South, which includes the rolling forks, supercell activity is projected to peak after two hours between 6-9 PM instead of 4-7 PM. This means more nighttime supercells.

“If you want a disaster, create a supercell where you can’t go out at night and visually check for threats,” he says to keep people from taking it seriously.

More densely populated than traditional tornado alleys in Kansas and Oklahoma, Ashley and Genzini said the shift east would put more people at risk. The population is poorer and often lives in mobile or manufactured housing, which is a more dangerous place in a tornado.

Ashley and Gencini said the southwestern United States is likely to be hotter and drier as the climate warms. The incoming air is getting juicier and unstable.

Hot, dry air from places like New Mexico sets a stronger “cap” where storms form when air masses collide in the spring. That upper limit means that storms are rare on the Great Plains. Gensini and Ashley note that as the weather front moves eastward, the pressure builds up, slowing the formation of the supercell and heading further east.

This occurs earlier in the year as February and March are warmer than before, but in July and August the hot dry air cap becomes so strong that supercell formation is likely to occur. When it gets difficult, Ashley and Gensini said.

It’s like playing with a pair of dice loaded against you, Ashley said. The other has more supercells and “also increases the odds of hazards, tornadoes and hail.”

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