Discussion: Notable is the sudden warming of ocean water west of South America and the attendant high pressure ridging. High pressure ridging is already intact east of Brazil due to warm waters. Presence of the anomalous warm regions of ocean water increase the risk that subtropical ridging will continue to dominate the South America climate causing dryness in Argentina and less rain than forecast by models in Brazil.
Fig. 1: Satellite view of the lack of precipitation across South America due to dominance of subtropical ridging on the climate pattern. Subtropical ridging is normally intense over large areas of warmer than normal water.
Fig. 2: Warm regions of SSTA are emerging around South America increasing the risk of dry weather producing subtropical ridging for late summer.
Fig. 3: The 15-day GFS OP forecast of anomalous 500 MB anomalies identifies 2 strong upper ridge cores on each South America coast.