The convection phase of the Madden Julian oscillation (MJO) is alive shifting eastward across the East Pacific tropics to tropical Africa and eventually western tropical Indian Ocean during the next 2 weeks. Intensity is marginal although ECM indicates weak-to-moderate intensity. Usually, an MJO shift through phase_1/phase_2 increases risk of hot and dry weather in Australia and a wetter regime for South America.

The ECM/ECM ENS continue a wet forecast bias across northwest South America, much of Brazil, and Uruguay during the past 30 days for all 15-day forecasts. This wet bias increases during the medium (6-10-day) and extended (11-15-day) range. The GFS/GFS ENS has a dry bias for West Brazil and Paraguay/Southeast Brazil.

Departing September, GRACE-based soil moisture anomalies analysis reveals improving conditions in the central/east-central Brazil soybean-growing areas while harsh drought in the southern soybean-growing areas receives beneficial rainfall in the latest 15-day outlook. The far eastern soybean growing-areas remain in drought with a dry outlook during the next 15 days.

Negative Indian Ocean dipole (-IOD) contributes to Central and East Australia rainfall during winter and spring while La Nina biases eastern continent wet. Both climate signals emphasize a wet bias to Australia climate and diminish dry risk. The -IOD regime is well established while borderline weak La Nina is present but without a clear atmospheric response. Consequently, the anticipated wet climate for early spring is patchy, based on September rainfall terciles. Note the dryness in key Australia crop areas in Victoria and eastward.