Weather forecasts are showing the arrival of instability in the upper levels of the troposphere to our country, associated with an Isolated High-Level Depression (DANA). Its influence in combination with a convergence zone of surface humidity, and the proximity of the monsoon trough to the south of Mexico, will cause thunderstorms that could present severe weather conditions.

The areas most affected by this condition will be mainly the northeastern, central, south, and southeastern states of the Mexican Republic. It is recommended to take precautions and be aware of the warnings issued by the corresponding authorities, due to possible hailstorms, abundant electrical activity, strong winds, and tornado formation.

According to the studies that have been carried out, the tornado season in Mexico extends from the end of March to October, with a higher incidence between May and August. It begins when the seasonal change from winter to spring occurs with the interaction of late frontal systems and moisture flows entering the continental region from the Gulf of Mexico. It also takes into account the passage of tropical or easterly waves, and of course, tropical cyclones.

How does a tornado form?

Depending on the type of phenomenon. In the case of a supercell tornado, the formation of mesocyclones must be considered, which require environmental conditions such as mid-level shear and high instability. On the other hand, non-supercell tornadoes are related to convergence lines and surface vorticity, without the need for an organized mesoscale system.

It is important to emphasize that both types of activity have been documented in the north of the country: supercell and non-supercell. This is due to the geographical characteristics and environmental conditions in this area (mainly in the northeast), where EF3 or higher are possible. On the other hand, in the center of the country, only non-supercell tornadoes have occurred.

Deadly tornadoes

In recent times, there have been deadly tornadoes causing serious damage, such as the one in Ciudad Acuña on May 25, 2015, and the one in Piedras Negras on April 24, 2007, both in the state of Coahuila. Mention may also be made of the Apodaca, Nuevo Leon tornado on May 8, 2020.

Since there are no long-term records of tornadoes, it is not possible to determine whether climate change will cause more tornadoes to form in Mexico in the future, or if their formation will spread to areas where they have not occurred before. Although some studies have suggested that climate change may increase the generation of extreme events, in the case of tornadoes, and Mexico in particular, there is not enough evidence to support this.