04/24/2022, 2:22 pm EDT
An intense negative phase of the Antarctic oscillation (-AAO) is forecast for this week. As a result, an unusually intense upper trough is forecast to evolve over Southern Argentina. To the north of that trough, dynamic forcing causes excessive heat to develop in central South America. Centered on Paraguay and far northern Argentina temperatures >100F this week. However, the much cooler air mass to the south roars northward in the 6-10-day period