Massive extreme hot air blankets the west, central and northern Argentina with scorching temperatures and maximums of up to 45°C | LUIS ROBAYO/AFP/METSUL METEOROLOGY
The heat was exceptional this Saturday in some provinces of Argentina, due to the exceptionally strong hot air mass, which is also causing extremely high temperatures well above normal in the south, midwest and parts of southeastern Brazil. Maximum temperatures above 45 °C were observed in the neighboring country.
According to stations from the Argentine National Meteorological Service (SMN), the maximum this Saturday reached 45.3 ° C in San Juan; 44.9°C in Mendoza; 42.2°C in La Rioja; 42.0 °C in Tinogasta; 41.9°C in San Martin; 41.6°C at Villa Reynolds; 41 °C in Villa Dolorores and Rivadavia; and 40.2 °C in Catamarca.
Today's extreme heat in western Argentina, in places close to the mountain range, in the socalled Cuyo region, was made worse by the hot and very dry Zonda wind. Relative humidity reached just 1% in Mendoza today amid extreme heat, causing power outages in various parts of the province.
Today's high in Mendoza under the Zonda wind is historic. It was the hottest day in the city's history. The official high of 44.9 °C was 0.5 °C above the previous alltime high temperature record of 44.4 °C set on January 30, 2003.
The Zonda is a wind typical of western Argentina, characterized by persistent and strong gusts. It is very hot and extremely dry, which often causes relative humidity to drop to levels below 5% to 10%.
The Zonda rises in the Andes and is predominantly westfacing. It usually occurs when there is instability on the other side of the Andes, on the Chilean side of the mountains.
Gusts of over 100 km/h can occur and problems such as lack of light and roofing, falling trees and a high risk of fire are common. The temperature is rising sharply, especially in the Mendoza region.
According to Argentina's National Weather Service, Zonda forms when moist air from the Pacific Ocean rises through the Andes, leaves its moisture on the Chilean side and descends on the Argentine side with very dry air that warms quickly as it descends into the Argentine part of the mountain range.
The SMN emphasizes that it can occur at any time of the year, but is most common between May and August. According to the Argentine Meteorological Agency, it occurs more frequently in the afternoon than at other times of the day. Sometimes it does not reach the surface and is called the “altitude zone”.
A similar phenomenon occurs in other parts of the world with mountain ranges with different names. These are the cases of Chinook in the United States and Canada, foehn in the European Alps, Canterbury in New Zealand and mountain wind in South Africa.
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