Zonda (Wind)

Zonda is a common in the Eastern Andean region of Argentina regional name for a foehn wind. It is a dry and often dust- bearing wind from the direction of the maritime polar air, which in the wake of the drop in level from the Andean ridge ( about 6000 m ) is heated adiabatically in further situated below regions and thereby may exceed wind speeds of 40 km / hr.

Although the Zonda comes almost everywhere in western Argentina, but its effects are strongest in the provinces of La Rioja, San Juan and to the north of Mendoza, as he is there influenced by the high Andes, while to the north the high levels weaken these winds.

The Zonda is caused by a northeasterly movement of the polar fronts and even though it is hot and dry in the lowlands, he is the main mechanism for snow in the higher regions, where it is known as the viento blanco (white wind) and there speeds up to 200 km / h can be reached.

According to studies from the period 1967 to 1976 the Zonda usually begins 12 to 18 clock and takes between one and twelve hours, but can last up to two or three days. In 90 % of cases it occurs between May and November.

In addition, a warm humid North Wind of the Pampas as a Zonda or Sondo is called, which is caused by an eastward across this moving area of low pressure.