The area in central-western Argentina (provinces of San Luis, most of Cordoba, western La Pampa, Mendoza), is called 'Hail Alley' by meteorologists, because it is usually in this area where the world's largest hailstones fall.
These hailstorms are the most violent in the world. The reason is the topography: the Andes Mountains are generally at their highest peaks in central-west Argentina, which cool pacific or antarctic air straight upwards.
Moist, warm air flowing down from Brazil, Paraguay, and Bolivia late in the spring (november, etc), towards Argentina rises, and meets these cool winds, which beging freezing the water dropplets in the warm tropical air. Because of the vertical height of the Andes, these winds allow the frozen ice to linger a lot longer than they would otherwise do, which can create trully massive hail stones.
A few tornadoes also occured in Cordoba, Santa Fe, Chaco, and Santiago del Estero Chaco provinces where a seven year old girl was killed.
Damage in the town of Coronel Moldes
Highway damage in Santiago del Estero province
Hot air from tropical South America meets cool pacific or cold antarctic air, and almost always in Argentina.