Taiwan's weather bureau Monday warned sailors about a new storm developing off the island.

Tropical Storm Bopha was 290 kilometers (174 miles) east-northeast of Taiwan's southernmost tip at 1200 GMT, the bureau said.

With a radius of 120 kilometers, Bopha was moving west at 15 kilometers per hour, packing center winds of 83 kilometers per hour.

The bureau said it expects the storm to lose power but warned sailors operating off the island to stay on guard.