A military exercise involving Japan’s Self-Defense Forces and thousands of U.S. troops is being adapted so drills can continue throughout Typhoon Champi, making use of the severe weather to offer troops experience of operating under extreme conditions.

The bilateral exercise , known as Keen Sword 27, is currently taking place in southern Japan.

Announcing the plan late on Wednesday, Rear Adm. Jay Clark, commander of the U.S. aircraft carrier USS Roosevelt, stressed that while safety comes first, Typhoon Champi presented an opportunity to challenge both their military personnel and hardware.

“Challenging weather is a serious part of real-world combat and disaster relief operations,” Clark said as the supertyphoon approached Japan’s southwestern islands. “We will use the weather to stress and test our people and our systems.”

This iteration of Keen Sword is the largest biannual exercise between Japan and the U.S.…