Southeast Brazil to Northeast Argentina Drought Development Underway

Cold Pattern Change Europe; Cold Threatens U.S. Last 1/3 of December
12/14/2021, 12:34 pm EST
South America Drought Concern Continues to Evolve
12/16/2021, 10:00 am EST
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We're in a pattern that may last well into summer...semi-permanent low-pressure east-southeast of Brazil and an attendant upper trough extending northwestward into Brazil causing steady rainfall compensated for by atmospheric subsidence causing dryness and heat in Southeast Brazil to Northeast Argentina raising drought concerns there.

Fig. 1: Last week, no rain was observed in a key agriculture zone experiencing developing drought from Southeast Brazil to Paraguay and Northeast Argentina.

Discussion: The focus is on developing drought for Southeast Brazil to Northeast Argentina. Last week this zone observed no rainfall (Fig. 1). The ECM ENS indicates little or no rainfall is likely for Northeast Argentina, East Paraguay, Uruguay and Southeast Brazil through the next 15 days (Fig. 2-4). Of course, the dry pattern is accompanied by anomalous heat accelerating the drying effect on soil moisture. In the extended-range, the pattern does not budge as central and northern Brazil are wet but to the south, a dry zone is attached to Southeast Brazil to Northeast Argentina (Fig. 5-6).

Fig. 2-5: The ECM ENS percent of normal rainfall forecast for the next 15 days indicates steady dryness across a drought concern area. The dry climate leads to anomalous heat in the 15-day outlook.

Fig. 6-7: ECM 3-4-week/5-6-week rainfall anomaly forecasts maintain dryness in Southeast Brazil to Northeast Argentina.