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Impact of Significant Rain in June to 2021 Crop Forecasts

By Adam Pasch

CIBO has been running monthly yield predictions since April. As predicted, the 2021 growing season started out well, with excellent conditions throughout the corn-growing region, allowing crops to get in the ground early. With crop development entering a crucial stage of yield determination in June, significant rainfall (> 8 inches more than normal) was observed in the midwest and southeastern United States, which was good news for the primary corn and soybean growing areas (Figure 1). However, most of this rain fell in only a few weeks.

May 2021                                                                                    June 2021 

Image 1 May 2021 Image 2 June 2021











Figure 1. Monthly Departure from Normal Precipitation from NOAA’s Advanced Hydrologic Prediction Service (AHPS) for April and May 2021.

USDA has not typically lowered their estimates between the June/July report. Did the USDA lower the numbers in the July 12th report? No. Should they lower them? Probably, because despite the significant increases in rainfall in the Midwest, the North-Central US is experiencing expanding areas of Severe drought conditions (Figure 2) and heavy rains are causing ponding and flooding.

Image 3 Midwest Drought 1

Figure 2. U.S Drought Monitor map for June 8, 2021 obtained from:

CIBO’s forecast data consists of an ensemble of predictions and provides the ability to investigate end-of-season yield predictions by different weather scenarios. A weather scenario is defined as a comparison of the forecast data compared to the 10-year climatology for the 2021 growing season. CIBO is continuing to investigate yield predictions for different weather scenarios (Table 1). 

Table 1. End-of-Season Yield Predictions (bu/ac) using forecast data starting July 2021.

Image 4 corn and soy yield predictions

What does the USDA think about the current conditions?

The USDA’s latest projections have not significantly changed since the May report. The main reason is that the USDA has not yet started to conduct in-field sampling. The Crop Progress and Condition for corn from USDA (Figure 4) shows a decrease in the percentage of crops that are Good + Excellent have fallen to levels not seen since 2019 for both corn and soybeans.

Image 5 Crop Progress

Image 6 Crop Progress

Figure 4. National Agricultural Statistics Service (NASS), Crop Progress Report for Corn (top) and Soybeans (bottom) for July 2021.

Make sure to check back in August, the day before the USDA WASDE is released to access CIBO’s forecasted numbers along with CIBO’s first estimate of planting dates. The USDA regularly announces national yield insights which tell you what will likely happen. CIBO’s monthly and real-time forecasts are able to tell you where and why yields are likely to happen. This insight creates new opportunities for actionable and hyper-local farming, agribusiness, sustainability and trading decision-making.

About the Author

Adam Pasch is the Director of Product Management – Platform at CIBO, a science-driven software startup. He is a Certified Consulting Meteorologist from the American Meteorological Society. Prior to CIBO, Dr. Pasch was the Weather Data Strategy and Operations Manager at The Climate Corporation and a Meteorologist Project Manager at Sonoma Technologies, Inc. He holds a Doctorate, Masters, and Bachelors of Science in Meteorology from Saint Louis University.



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