Weather models differ considerably on Brazil’s precipitation forecasts, with GEFS and AIFS forecasting less rainfall than ECMWF. For October 26 to November 9, the production-weighted precipitation forecasts show: • Brazil soybeans: GEFS 88.1% | AIFS 77.5% | ECMWF 106.5% of normal • Brazil first-season corn: GEFS 111.3% | AIFS 87.8% | ECMWF 121.3% of normal But which model has been more accurate recently? The 14-day rolling precipitation RMSE charts show that AIFS has generally recorded lower forecast errors than GEFS, GFS, and ECMWF in recent runs, particularly for days 8–14. With these differences in precipitation forecasts, which model should grain traders give more weight to? Grain traders, use the link in the comments to request a risk-free trial of CropProphet! 👇 #OOTT #AgWx #GrainMarkets #Corn #CornBelt #Soybeans #Milho #Soja

Could excessive early-June rainfall have contributed to weaker corn yields in parts of Illinois and Iowa? In central and western Illinois and east-central and southeast Iowa, three-day rainfall totals reached up to 4 inches, with many counties recording one of their five highest early-June three-day totals since 1981. These areas also recorded the largest declines in CropProphet's corn yield forecasts among Iowa and Illinois districts between June 1 and October 15. By comparison, central and west-central Iowa did not experience similarly heavy early-June rainfall at the county level, and corn yield forecasts in those areas finished above trend. CropProphet's June 16 and June 30 commentaries which are sent to customers had already documented declines in county-level yield forecasts in areas affected by excessive rainfall. The GIF tracks observed precipitation, expressed as a percentage of normal, alongside county-level corn yield forecasts relative to trend throughout June 2026. #OOTT #AgWx #GrainMarkets #Corn #CornBelt

How do today's Argentina corn and soybean precipitation forecasts compare with historical forecasts issued around the same time of year? Our Point-in-Time Weather Forecast API provides access to 8+ years of archived weather forecasts, allowing users to compare current model forecasts against historical forecasts and conduct backtesting. For Argentina's week-two precipitation forecast (Oct 26-Nov 1), AIFS-ENS ranks among the driest 11% of comparable historical forecasts for corn and the driest 6% for soybeans. The graphics compare today's 00Z ECMWF, GEFS, GFS, and AIFS-ENS forecasts against historical 00Z forecasts initialized within ±15 days of October 19 from 2017-2026. #OOTT #AgWx #Corn #Soybeans #Argentina #CornBelt #GrainMarkets

ECMWF, AIFS, and GEFS forecast substantially below-normal precipitation across Argentina's corn and soybean production regions in week two (Oct 26–Nov 1). Argentina's corn production-weighted precipitation forecast for days 8–14: • ECMWF: 72% of normal • AIFS: 55% of normal • GEFS: 54% of normal Argentina's soybean production-weighted precipitation forecast for days 8–14: • ECMWF: 58% of normal • AIFS: 49% of normal • GEFS: 46% of normal Get a risk-free trial of CropProphet using the link in the comments below! 👇 #OOTT #AgWx #Corn #Soybeans #Argentina #GrainMarkets

US corn and soybean harvest progress could accelerate over the next seven days, with all three forecast models showing substantially below-normal precipitation before a wetter pattern develops in week two. US corn/soybeans production-weighted precipitation forecast for days 1-7 (Oct 19-25): • ECMWF: 46% / 33% of normal • AIFS: 28% / 19% of normal • GEFS: 47% / 35% of normal The forecast shifts toward above-normal precipitation in week two (Oct 26-Nov 1), with the AIFS model showing a substantially wetter outlook than the ECMWF and GEFS. US corn/soybeans production-weighted precipitation forecast for days 8–14: • ECMWF: 118% / 103% of normal • AIFS: 194% / 173% of normal • GEFS: 122% / 109% of normal #OOTT #AgWx #Corn #Soybeans #CornBelt #GrainMarkets

How has soybean planting shifted across Brazil over the past 50 years, and why does it matter for weather forecasts? In the 1970s, soybean cultivation was concentrated primarily in southern Brazil. Since then, soybean planting has expanded substantially into central Brazil, particularly Mato Grosso and Goiás, as well as other northern producing regions. The attached maps and GIF illustrate how soybean cultivation has expanded and shifted geographically across Brazil over time, showing changes in the share of land used for soybeans. With the ECMWF, GEFS, and AIFS forecasting below-normal precipitation in Mato Grosso over the next two weeks, rainfall across this region is important to monitor as Brazil's 2026/27 soybean planting season progresses. This geographic shift in soybean cultivation also highlights the value of CropProphet's production-weighted weather indices, such as Brazil soybean production-weighted precipitation. These indices account for where soybean production is concentrated when aggregating weather conditions and forecasts, rather than weighting all geographic areas equally. #OOTT #AgWx #Soybeans #Brazil #GrainMarkets #Soja

Brazil soybean weather: All three major forecast models indicate below-normal rainfall in Mato Grosso over the next two weeks. Today's 00z ECMWF forecast has shifted drier for October 16–22, bringing it closer to the GEFS and AIFS forecasts. Mato Grosso precipitation forecasts (% of normal): Week 1 (October 16–22) • ECMWF: 62% • GEFS: 35% • AIFS: 40% Week 2 (October 23–29) • ECMWF: 73% • GEFS: 46% • AIFS: 67% The ECMWF reduced its Week 1 Mato Grosso precipitation forecast by 13% of normal compared with yesterday's 00z run. All three models now consistently forecast below-normal rainfall across Mato Grosso during both weeks, although the GEFS remains the driest. With Brazil's 2026/27 soybean planting underway, rainfall amounts and distribution across Mato Grosso will be important to monitor for soil moisture, planting progress, and crop establishment. #OOTT #AgWx #Soybeans #Brazil #GrainMarkets #Soja

"The trade is focused on is not the forecast for El Niño two months out. It's what's going on right now." @StandardGrain So, let's take a look at the precipitation forecast for Brazil soybean producing regions over the next 2 weeks. Today's 00z Brazil soybean production-weighted precipitation forecast for week 1 (days 1-7): • ECMWF: 107% of normal • GEFS: 80% of normal • AIFS: 77% of normal Today's 00z Brazil soybean production-weighted precipitation forecast for week 2 (days 8-14): • ECMWF: 123% of normal • GEFS: 105% of normal • AIFS: 105% of normal #OOTT #AgWx #Brazil #Soybeans #Soja #GrainMarkets