Tokyo Olympic organizers on Monday moved the medal events in the surfing competition a day earlier than scheduled, marking the latest change to the program caused by Tropical Storm Nepartak as it churned toward Japan's main island.

The storm is expected to head over Japan's northeast coast on Tuesday and could dump heavy rain on the capital just days after the start of the Games.

The medal heats for surfing, making its Olympic debut in Tokyo, were due to be held on Wednesday, but the strong swell provided by the Nepartak is expected to abate by then and impact the waves, prompting organizers to move them forward by a day.