South America Summer 2022/2023 Outlook
One of the main teleconnections heading into the summer season will be the rare triple La Nina which should carry through much of the season. Even if sea-surface temperatures return to neutral in January, the atmosphere should remain La Nina-like through the end of the summer season.
Courtesy Australia BOM and WMO
Looking at ENSO, other teleconnections and the recent global pattern, we came up with some top analog years. The composite of December, January and February temperature and precipitation anomalies for the analog years are shown below.
Taking everything into account, here is the regional breakdown of our summer outlook.
Northern Argentina and Uruguay:
Following a dry and rather cool spring, the drier-than-usual pattern is expected to persist across these areas through much of the summer. However, there can be period of wetter weather into these areas in January. Even with a spell of wetter weather around midseason, the season overall should average on the dry side of normal.
The continuing drier pattern should result in a further reduction of soil moisture which should allow for heat to build in these areas with a good chance for heat waves, especially starting later in December. The combination of heat and below-normal rainfall can result in stress on crops and could cut into corn and soybean production.
The wildcard is that a wetter period in January would be timely for reproductive corn but may be moot point if soil moisture early in the season is too low for proper germination and establishment.
Southern Brazil and Paraguay:
Much of Rio Grande do Sul will experience a similar pattern to northern Argentina and Uruguay with below-normal rainfall and above-normal temperatures. Crops will likely experience stress in these areas. However, a southern displacement of the storm track late in the season could favor a wetter end to the season in portions of Rio Grande do Sul, especially over the northern half of the state. A wetter end of the season would certainly be helpful, as crops tend to enter their reproductive and maturing phases during that time.
Stalling fronts should result in rainfall near- to above-normal from Santa Catarina to Rio de Janeiro, Minas Gerais and Mato Grosso. Clouds and rain in these areas can hold temperatures near to perhaps slightly below normal. Heat can be limited in these areas, but there is still a chance for a spell of heat during January. Overall, conditions should be favorable for crops, including soybeans, across these Brazilian croplands.
Much of Paraguay will have near- to above-normal rainfall and temperatures, but southeast Paraguay should be drier than normal with a good chance for heat waves later in the season. A drier-than-normal pattern during the summer could reduce flow for the famed Iguazú Falls, especially if the dry pattern becomes more severe than expected.
Northern Brazil, Venezuela and Colombia:
La Nina conditions are expected to support near- to above-normal rainfall in these areas. The rainfall should be helpful for hydroelectric power generation in Venezuela.
The combination of cloud cover and rainfall should limit temperatures to near to below normal in these areas. If rainfall is close to normal or even slightly below in some areas, then there is a good chance temperature anomalies can be warmer than currently forecast.
Ecuador and Peru into Bolivia:
The cool waters associated with La Nina and a negative South Pacific Meridional Mode (SPMM) should result in rainfall below normal with temperatures near to below normal, especially toward the coast. However, interior Peru and northern and eastern Bolivia can be warmer than normal with a chance for near-normal rainfall, thanks to a possible uptick in rainfall across these areas in January and February.
Rainfall prospects look favorable across the Amazon River basin as well.
Much of northern and central Chile is expected to be drier and warmer than normal with a chance for several heat waves. Even though we expect central Chile to be drier than normal, we cannot rule out a couple of opportunities for light rainfall early in the season. The better chance for precipitation can be over the central Andes versus the valleys. Meanwhile, high-level heat source thunderstorms over the northern Andes mid- to late season can result in rainfall closer to normal in these areas.
Southern Chile into southern Argentina can turn stormier late in the season which can result in precipitation close to normal in some areas. If the stormier pattern fails to materialize, then this area will be drier than normal with a chance for temperatures to be higher than expected.Report a Typo