Zonda wind events: When do they arrive to the metropolitan area of Mendoza?

FEDERICO A NORTE; JORGE RUBEN SANTOS; ANDRES HOFER; DIEGO ARANEO; SILVIA CARMEN SIMONELLI

Montevideo

Conferencia; ?Conference for Latin America and Caribbean: developing, linking and applying climate knowledge?; 2014

WRCP (World Research Climate Program )

Zonda wind is a kind of Foehn wind commonly observed in the lee of large mountain ranges as Andes Cordillera and is typically associated with large temperature increases and relative humidity decreases due to adiabatic compression of the descending wind. Near the mountains of the western Argentina  specially on San Juan and Mendoza  provinces.,  Zonda winds have been documented, however is  a challenging task to diagnostic and predict the event  because is  a small-scale phenomenon which strongly depends on topographically feature.Zonda climatology presents a maximum frequency of occurrence during the winter in the southern hemisphere (may and august), and a secondary peak during the spring (october and november). Although the necessary meteorological conditions for the occurence of the Zonda to blow on the surface of Mendoza city are known, there are still no suitable tools to achieve a perfect forecast of this windstorm.The purpose of this study is to explore the synoptic and mesoscale features associated with the Zonda wind.  Ten different Zonda episodes were analyzed. It was observed that a strong convergence at 200 hPa together with an intense low pressure system known as Depresión del Noroeste Argentino (DNOA) were present in each Zonda episode. It is worth noting that during a weak (intense) event, a weak (strong) jet-stream at 200 hPa was associated. Also the zonal (meridional) pressure differences across (along) the Andes mountain range play an important role during the genesis stage of the windstorm.