Several people were injured and around 230 buildings were damaged after a tornado touched down near the city of Franklin in Robertson County, Texas, on Saturday 13 April 2019. A large number of trees were knocked down by the storm, and several buildings lost their roofs, with the worst damage reported to mobile homes, many of which were destroyed completely. The entire of Franklin is reported to be without electricity following the storm, as is the nearby community of Bremond. The only fatalities associated with the storm have been reported from Angelina County, about 200 km to the east of Franklin, where two children died after the car they were travelling in was hit by a tree.
Damage in the city of Franklin, Texas, following a tornado on 13 April 2019. Scott Engle/My San Antonio.
The tornado is estimated to have been a three on the enhance Fujita scale (or an EF-3 tornado); such a tornado will produce sustained windspeeds of 254-334 km per hour, potentially strong enough to damage even well built structures, topple trains and throw large cars some distance.
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.
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.
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