South America: High temperatures forecast to persist in northern Argentina, southern Brazil, and across Paraguay through at least March 17 /update 2

Forecast models indicate that high temperatures will persist across parts of northern Argentina, southern Brazil, and much of Paraguay through at least March 17. Temperatures exceeding 40 C (104) F are possible across parts of the affected area over the coming days.

As of March 14, Argentina's National Meteorological Service (SENAMHI) has issued red high-temperature warnings (the highest level on a three-tier scale) across much of Chaco and parts of central and western Formosa, eastern Salta, and northeastern Santiago del Estero provinces. Orange high-temperature warnings are in place for parts of eastern Chaco, western Corrientes, eastern Formosa, eastern Misiones, northern Santa Fe, and central and eastern Santiago del Estero provinces. Yellow high-temperature warnings are in place across much of the rest of Corrientes and Misiones provinces and parts of western Entre Rios and central Santa Fe provinces.

Brazil's National Institute of Meteorology (INMET) has issued a red heatwave warning (the highest level on a three-tier scale) across parts of central and southern Mato Grosso do Sul, central and western Parana, far northern Rio Grande do Sul, central and western Santa Catarina, and northern and western Sao Paulo states through March 16. Orange heatwave warnings are in place for parts of eastern Parana, central and western Rio Grande, and eastern Santa Catarina states. Yellow warnings are in place across parts of northern Mato Grosso do Sul, southern Minas Gerais, eastern Rio Grande, and central and far northern Sao Paulo states.

Paraguay's Directorate of Meteorology and Hydrology has warned of maximum temperatures of around 40 C (104 F) and minimum temperatures of 26 C (79 F) across much of the country through at least March 17.

Officials could upgrade or expand the alerts as the heatwave develops over the coming days.

The high temperatures may result in increased energy and water demand and a heightened risk of heat-related illnesses, such as heat exhaustion and heat stroke.

The extended period of oppressive heat and dry conditions may produce ideal circumstances for further wildfire growth throughout the affected areas. Heatwaves also pose a threat to vulnerable groups - such as the elderly, children, pregnant women, and those with respiratory illnesses - due to the increased possibility of heat stroke or heat exhaustion during prolonged exposure to high temperatures. These health risks could also extend to relatively healthy individuals during significant heatwave events. In addition to significantly impacting athletes and those who work outdoors, high temperatures can cause problems for people using mass transit. The lack of air conditioning and cramped vehicles during rush hour may lead to some passengers being hospitalized for dehydration.

Very high temperatures may warp rail tracks and force passenger and freight trains to operate at reduced speeds. Road surface damage is also possible, and overheated vehicles may worsen traffic problems in urban areas where congestion is already a problem. Commercial trucking disruptions might occur, as very high temperatures put more stress on vehicles, making tire blowouts more common. Major flight disruptions are unlikely at regional airports, but general aviation disruptions are possible, and some airfreight carriers could reduce cargo loads. High temperatures could lead to an increased demand for electricity, which might trigger localized brownouts or blackouts, exacerbating hazardous conditions when air conditioning is no longer possible.