Heavy rain soaked areas of Oahu and Maui on Saturday as a midlevel disturbance continued to move slowly southward across the state.

The National Weather Service said the strong low aloft combined with ample moisture would continue to produce heavy rain and thunderstorms, and the related threat of flash flooding, through Sunday morning.

Pea-sized hail, about a quarter-inch in diameter, was reported in Waipahu at about 11:45 a.m. Saturday.

Between 11 a.m. and 5 p.m., just over 2 inches of rain fell on Ahuimanu Loop on Oahu. Other affected areas during the same period included Waihee Pump (1.32 inches), Moanalua (1.25) and Hakipuu Mauka (1.13).

On Maui, monitors at Puu Kukui recorded 1.85 inches of rain over the six-hour period. In addition, Hana Airport recorded 2.37 inches of rain over the 24-hour period ending at 5 p.m. Saturday.

The inclement weather continued through the early evening as National Weather Service radar detected heavy showers along the windward slopes of East Maui and the windward slopes of the Koolau range on Oahu. The area between Kaaawa and Kahuku also experienced heavy rainfall. The shower activity prompted a flood advisory for both islands through midevening.

A flash-flood watch for all main Hawaiian islands was set to expire at 6 a.m. Sunday.

Meanwhile, the Department of Health issued a brown water advisory for Waimea Bay and the Bamburas surf area due to heavy rain. The public is advised to stay out of floodwaters and stormwater runoff due to possible overflowing cesspools, sewer manholes, pesticides, animal fecal matter, dead animals, pathogens, chemicals and associated flood debris.