Quantification of Change

The mission of CropProphet is to quantify the impact weather has on grain crops. A substantial amount of data and information is required to achieve our mission. The information available enables us to provide unique analytics to better inform the decisions CropProphet customers make.

In this post, we discuss the importance of calculations showing the magnitude of weather variables such as precipitation and growing degree days that have occurred or is being forecast to occur. This product enhancement means CropProphet users don’t have to guess, for example, how much more precipitation is in the forecast compared to yesterday’s forecast. Users don’t have to guess how many more or less cooling degree days the weather forecast contains compared to the prior forecast run. It’s now calculated.

Even though the impact of weather on crops occurs over an entire summer during the crop years, weather can drive short term changes in the futures markets because of changes in conditions and changes in the weather forecast itself. Much of the weather information available in the market is exactly that: weather information. It’s subject to interpretation, estimation, conjecture, and speculation regarding any piece of information’s impact on corn and soybean yields. For example, the graphic below is widely used in the market and depicts the US NWS 7-day precipitation forecast.

Map of the NWS 7-Day Precipitation Forecast
NWS 7-Day Precipitation Forecast

But, what does this mean for the corn crop? Is the 3-4 inches of rain estimated to fall in Illinois, Indiana, and Kentucky significant?
To answer that question, we recently released a CropProphet enhancement that quantifies the impact of this type of forecast based on production weighted averages over all counties that grow corn, soybean, and winter wheat. Our version of the same forecast (from NOAA’s GFS model) is shown below. It’s forecast to rain 2.1 inches across the corn belt over the next seven days.

We are now providing this enhancement for every map-based view in the product. You might be wondering “What about the same calculation for your yield predictions?” That analysis is the original functionality of CropProphet. CropProphet already integrates of a wide range of weather information to create yield and production forecasts. We already quantify the impact of weather on crop yields across the corn belt. It’s the yield forecast! Customers have asked for additional quantification of the information that drives the forecasts.

This enhancement allows users to objectively quantify the potential impact of weather factors that affect crop yields.

The 1 week precipitation forecast from the GFS and ECMWF forecast models in terms of percentage of normal during the forecast time period.

The graphic above calculates the amount of precipitation relative to normal amounts of rainfall from both the GFS and ECMWF model. With this information, it’s apparent that greater than normal precipitation is forecast and that the ECMWF is forecasting more precipitation. But, with this quantification, a user now also understands that US corn growing regions will receive 172% more than normal according to the GFS model but the ECMWF is forecasting even more at 197% of normal.

This quantification also extends to comparison of the run-to-run differences from the weather models, as shown below.

Map of Growing Degree Days differences.

Using this map based analysis, a user now knows that across all corn growing regions the 24 change in the weather forecast is different by only -1.4 oF as forecast by the ECWMF whereas the GFS model forecast change is -7.9 oF growing degree days. Relative to the entire corn belt, that is a small change.

The same calculation for precipitation is also available.

Run-to-run change of the GFS and ECWMF precipitation forecast.

This enhancement means that CropProphet users no longer have to guess the significance of the a weather forecast or a change in the forecast from the previous day means. We’ve quantified the the forecasts in terms of the production weighted geography across all counties that grow corn, soybeans, or winter wheat. This provides much more context to the weather forecast information and allows users to make better informed decisions.