This radar image from the National Weather Service shows the powerful kona storm over Maui on Friday evening. Photo courtesy National Weather Service

The National Weather Service in Honolulu has issued a flash flood warning for Maui until 8 p.m. Friday.

According to the NWS, radar indicated heavy rain over the island at 5:37 p.m. Rain was falling at 1 to 2.5 inches per hour with the heaviest rainfall on the south-facing slopes of Haleakala, where the Ukumehame Gulch has risen significantly.

Flash flooding is ongoing or expected to begin shortly.

People should stay away from streams, rivers, drainage ditches and culverts, even if they are currently dry.

The warning may need to be extended beyond 8 p.m. if flooding persists.