The National Weather Service has issued a flood advisory for Maui until 6 p.m. today while all other islands are under a flash-flood watch through tomorrow night.

Sections of Maui have been hit with heavy rainfall and thunderstorms for most of the day, forecaster Jonathan Hoag said.

The moist southern flow of showers affecting the Islands is being caused by an upper atmospheric low-pressure center 700 miles to the southwest, he said. Weather should be improving after tomorrow, he added.