At least seven people have died and many more have been injured as tornadoes and severe storms swept across the southern United States on Wednesday 22 and Thursday 23 April 2020. At least three people died and more than twenty were injured when a tornado hit the town of Onalaska in Polk County, Texas, destroying 46 houses and damaging 245 more. Two people died in the city of Madill in Marshall County, Oklahoma, which is reported to have suffered severe damage after being hit by a tornado. In Louisiana a man is reported to have died after falling into a drainage ditch in the city of Mansfield in DeSoto Parish, and a woman is reported to have died in a storm in the town of Lecompte in Rapids Parish. Elsewhere the city of Adel in Cook County, Georgia, is reported to have suffered damage to a number of properties after being hit by a tornado, as is the city of Tallahassee, in Leon County, Florida. In Alabama two emergency workers are reported to have been injured by a falling tree in the city of Anniston in Calhoun County, while attempting to rescue a homeowner trapped by an earlier treefall. Around 150 000 homes and businesses across the southern US are reported to be without electricity due to fallen power lines.
A tornado over the city of Madrill, Oklahoma, at about 5.00 pm local time on Wednesday 22 April 2020. NBC.
Tornadoes are formed by winds within large thunder storms called super cells. Supercells are large masses of warm water-laden air formed by hot weather over the sea, when they encounter winds at high altitudes the air within them begins to rotate. The air pressure will drop within these zones of rotation, causing the air within them so rise, sucking the air beneath them up into the storm, this creates a zone of rotating rising air that appears to extend downwards as it grows; when it hits the ground it is called a tornado.
Tornado damage in Woodworth, Louisiana. USA Today.
Tornadoes can occur anywhere in the world, but are most common, and most severe, in the area of the American mid-west known as 'Tornado Ally', running from Texas to Minnesota, which is fuelled by moist air currents from over the warm enclosed waters of the Gulf of Mexico interacting with cool fast moving jet stream winds from the Rocky Mountains. Many climatologists are concerned that rising temperatures over the Gulf of Mexico will lead to more frequent and more severe tornado events.
Simplified diagram of the air currents that contribute to tornado formation in Tornado Alley. Dan Craggs/Wikimedia Commons/NOAA.
See also...
Follow Sciency Thoughts on Facebook.