Cool and wet conditions this spring, especially in the Great Lakes and eastern corn belt, have kept planting behind schedule. Indiana only has 62% of the corn planted, and Ohio only reports 51% planted as of late May. These are well below the averages of 77% and 66% in these states. This cool and wet spring was not all that surprising when looking at a few analog years containing a significant El Nino. The images below show April through June temperature and precipitation anomalies for 1941 and 1983. The spring of 1941 was very cool and wet in the southern Plains extending into the southwestern corn belt with warmer and drier conditions in the northern corn belt while the spring of 1983 featured much more widespread cool and wet conditions.
1941 and 1983 Spring Temperature and Precipitation Anomalies
Both 1941 and 1983 saw an abrupt shift to hot and dry conditions for the summer. The next image shows July through September temperature and precipitation anomalies for 1983 and 1941. The heat and drought was intense across the heart of the corn belt in both of these years, but the greatest temperature anomalies were centered farther southeast into the Ohio and Tennessee Valleys in 1941 compared to 1983.
1983 and 1941 Summer Temperature and Precipitation Anomalies
The table below shows June through August temperature and precipitation departures for the Midwest after strong El Nino events. 1973, 1983, and 1998, each saw warm to hot summers with 1983 being the hottest. Out of those three years, 1973 and 1983 saw below normal rainfall in the Midwest throughout the summer, but 1998 saw above normal rainfall. The consensus among these years points toward above normal summer temperatures for the Midwest in 2016 with near to slightly below normal precipitation.
Midwest Jun-Aug Temp and Precip After Strong El Nino
Crop yields for corn and soybeans in 2016 may not be as low as some may fear. The chart below from the Midwest Climate Center shows Midwest corn and soybean yields for years after a strong El Nino. The only year that had extremely low yields for both corn and soybeans was 1983. Corn actually yielded slightly better than soybeans overall when looking at all of these years. 1958 and 1973 were similar to recent trends in 2016 with below average corn yields in the eastern corn belt states. The late planting of corn this year in the eastern corn belt could lead to lower yields. In fact, corn planting is far enough behind schedule that many acres could see a switch to soybeans in the eastern corn belt for this upcoming growing season.
Midwest Corn and Soybean Yields After Strong El Nino From the Midwest Climate Center