UPDATE: 9:15AM. USDA has released a new forecast slashing the forecast size of the 2012 corn crop. Details here.
You are seeing an unusual map: Rain is forecast for every Canadian province shown on the map, each of the 48 states shown on the map, and northern Mexico.
With recall to the substance of the chart, the rain in the Mississippi Valley may be enough to help the soybean crop. While the rain will occur in the eastern corn belt, the crop may be too far along to be much help.