The massive invasion of Japan planned for Nov., 1945 required accurate knowledge of the weather conditions that moved across the Japanese Islands from Siberia. The U.S. Navy MOKO Expedition was sent to Siberia to forecast the weather for the invasion forces. The MOKO Expedition arrived in Siberia on 24 Aug. 1945 and became operational on 15 Oct. 1945. The desperate efforts to set up a major weather station in time for the planned invasion were successful in spite of the exasperating tactics of the Soviets, the incredibly cold weather, and the primitive environment. Yoder served as an meteorologist on the expedition. Here is his story of the U.S. Navy Expedition. Photos and maps.