The National Weather Service has extended a flash flood watch for the eastern portion of the state to include Oahu from Tuesday morning to Wednesday afternoon as Tropical Storm Felicia continues to move toward Hawaii.

The storm is expected to produce “extremely heavy rainfall with the potential for widespread flash flooding increasing on Tuesday and continuing into Wednesday,” the National Weather Service said.

The flash flood watch continues for Kahoolawe, Lanai, Maui, Molokai and the Big Island from Monday morning to Tuesday afternoon.

People in flood prone areas need to prepare for the possibility of torrential rains associated with Felicia, the weather service said. Rock and mudslides are also possible once the heavy rains begin.

Heavy rainfall could occur well away from the center of the storm, the weather service added.

A flash flood watch means conditions may develop that lead to flash flooding.