Core of Argentina Drought Area Continues to Strengthen

Fig. 1-2: Daily soil moisture analysis for South America and seasonal trend plus the percent of normal rainfall for the past week.

Discussion: Daily soil moisture analysis across South America identifies the drought zone hovering across Argentina and Uruguay and into far Southeast Brazil while the seasonal change has been wetter across Central and East Brazil (Fig. 1). Last week, percent of normal rainfall analysis reveals sharp dryness centered on Uruguay and not quite as dry in north/east portions of Argentina (Fig. 2). Central and western Argentina received some heavy rain. Rain was also heavy in parts of Paraguay to southwest Brazil.

Fig. 3-4: South America 15-day percent of normal rainfall forecast by the GFS and ECM ENS 15-day temperature anomaly outlook.

The 5-day outlook is mostly dry across the Argentina and far southeast Brazil drought region. Anomalous heat risk is high in Argentina only. In the medium-range, wet risk increases. Thundershower activity is more widespread across Southeast Brazil reaching Uruguay at times and also Paraguay into northern Argentina (Fig. 3). However, the core drought zone in northeast/east Argentina is likely mostly dry and somewhat hotter than normal (Fig. 4) as drought worsens.

In the extended-range, wet weather is projected to shift into the northwest quadrant of South America leaving Brazil at increased risk for areas of drier than normal climate (Fig. 5-6). A narrow band of rainfall channeled southward from the northwest South America source region and across parts of the Argentina drought region is expected.

Fig. 5-6: NCP CFS V2 week-3/week-4 ahead precipitation anomaly forecasts across South America.