The Hawaiian Volcano Observatory says an ash plume from within Kilauea volcano's summit crater has risen as high as 12,000 feet above sea level.
Ash has been wafting continuously from a vent in the crater, Halemaumau, and drifting southwest, causing ashfall and volcanic air pollution to be reported as far as 18 miles away.
Authorities have issued an ashfall advisory for the island's southernmost district until 6 p.m.
Ormat Technologies, which owns a geothermal energy plant in the area, says there is a low risk of lava impacting the facility.
The plant, Puna Geothermal Venture, was shut down after Kilauea first erupted on May 3, and provides roughly one-quarter of daily energy demand on the Big Island.