Watching Northwest/North Brazil Second Corn Crop for Drought Risk
01/27/2023, 5:54 am ESTRegional SSTA Report: Anomalous Warm Gulf of Mexico = Major East-central U.S. Precipitation Events!
01/31/2023, 4:21 pm EST
Fig. 1-4: Percent of normal rainfall across South America for Jan. 22-28, 2023, and the GFS rainfall amount forecast for the next 15 days.
South America discussion: Where it rains, it pours is thematic of the Jan. 22-28 rainfall pattern across South America soybean, wheat and corn growing areas (Fig. 1). Up to 4 in. of rain was observed in far northwestern Argentina and a small area near the Uruguay state line. The extreme rainfall amount is very confined and only locally beneficial to areas of drought. A broad area of 2-3 in. of rain in Central Argentina is mostly west of key crop areas. Extreme rainfall was observed in Central/South-central Brazil in Brazil’s second corn crop region.
The forecast reveals an area of heavy rain across Paraguay and eastward this week (Fig. 2) with a similar forecast although slight northward shift in the 6-10-day period (Fig. 3). An upper-level low-pressure trough extending northwestward into this area from east of Uruguay is the trigger for this rainfall. On the back side of the upper trough, subsidence keeps the drought area across Argentina rain free! The Argentina drought will intensify through the first third of February. In the extended-range, GFS indicates potential for significant rain in Argentina although that forecast is made with low confidence (Fig. 4). The Brazil forecast is certainly trending wetter over-the-weekend.