The role of complex terrain in the generation of tornadoes in the west of Mexico

Tornadoes are extreme manifestations of severe storms that occur around the world. In Mexico, the most affected region by the tornado phenomenon is the Trans-Mexican Volcanic Belt (TMVB), a complex topographic region in the central part of the country with a large population density. This research work aims to investigate the role of the complex topography in the generation of instability conditions that favored the formation of two tornadoes almost in the same place (western TMVB) on August 7, 2012, and September 16, 2014. Numerical experiments with the WRF-ARW model were performed in order to obtain knowledge about several important weather conditions preceding each tornado event and to identify the role of the complex terrain in the generation of instability necessary for their formation. Notwithstanding this real complexity, similar patterns in instability parameters and meteorological variables were found for the two tornadoes. The complex terrain seems to be essential in the generation and increase in instability preceding each tornado event. This work is the first approach to understand the meteorological phenomena, in the complex topography of Mexico, which leads to the formation of tornadoes. Understanding natural hazards such as tornadoes represents a first phase in the process of disaster risk reduction.