The anticipated El Nino should bring “ideal agricultural conditions,” to the Southern Plains and into South America, she said. “Brazil and Southern Argentina should have great crops, which could drive down the price of corn.”

Garriss said weather change favors some areas and harms others. With the current PDO changes and warmer water to the East, moisture moves into Canada and the United States. “From the mid 1970s to the late 1990s, the United States and Canada enjoyed the most benign combination of the PDO and AMO.”

Weather winners and losers emerge from the oscillation changes. Winners include the United States’ Midwest, Northern and Central China, India, Japan, Southern Africa, Eastern Australia and Brazil. Losers include the Andes Republics and Argentina, California and the Southwest United States, Southern China, Pakistan, East Africa, Western Australia, and North Korea.

“La Nina weather patterns magnify the effects of a cold PDO,” Garriss said. “Also, prices go up with La Nina.”

In the 1960s and 1970s, corn prices were low. In 1975, prices rose when the PDO changed. “The pattern holds for wheat, corn and soybeans but not for rice, which is a tropical crop. La Nina sends prices up.”