UPDATE (6:30 p.m.) – Both lanes of Highway 19 between the 38-39 mile markers are closed due to downed utility poles, police say. HELCO is on scene. “Alternate route on mailbox Rd./Old Government Road,” a police Nixle alert stated. “It is recommended that drivers stay off the roadway.”

(BIVN) – The onset of strong winds and waves associated with a powerful low pressure system has begun in some areas of Hawaiʻi Island, officials say.

“All persons are advised that the peak period for this storm and impacts are forecast for later tonight into Monday morning for the Big Island,” Hawaiʻi County Civil Defense reported in a winter storm alert message on Sunday.

Power outages have already been reported. The Hawai‘i Electric Light Company is asking customers to conserve electricity use this evening, especially between 6 p.m. and 8 p.m. “Crews are working to restore transmission lines that supply power from independent power producers Hamakua Energy Partners and Hawi Renewable Development to the electric grid,” HELCO said. “Although the company expects to have sufficient generation to meet the early evening peak demand for electricity, the unexpected loss of generating units could cause a shortfall. If that happens, brief power outages may be implemented around the island to maintain system stability.”

“Since midnight, there have been outages across the island, all caused by high winds toppling trees or blowing branches onto lines,” HELCO says. “Most customers were restored fairly quickly, though in some cases repairs were complicated by the need to clear debris in remote areas, particularly in the North Kohala, Hamakua Coast and Honoka‘a. Hawai‘i Electric Light has extra crews working and can bring on additional crews as needed over the next several days.”

Due to power outages in North Kohala, the Department of Water Supply has issued a water restriction from Hawi to Makapala. Residents are asked to limit water use to drinking and health purposes only until power is restored.

A High Wind Warning is in effect for Hawaiʻi Island, with northwest winds at 25 to 40 mph with gusts to 60 mph. On the summits of Mauna Kea and Mauna Loa, west winds are expected to be 70 to 120 mph with localized gusts over 145 mph.

“Snow has been reported over the summit area of Haleakala as well as accumulating ice on the Big Island summits, so a Winter Weather Advisory is in effect,” the National Weather Service says.

The access road to the summit of Mauna Kea remains closed, and rangers report winds over 150 mph.

UPDATE: At 4:40 p.m., a wind gust on the summit of Mauna Kea was measured at 191 mph, according to the National Weather Service.

All county and state beach parks and campsites are closed.

Waipio Valley, Laupahoehoe Road and South Point Road are closed and open to residents only, the County says. Also, Bayfront Highway in Hilo is Closed between Pauahi Street to Waianuenue Avenue.

A High Surf Warning is in effect for West Hawaiʻi, and a High Surf Advisory is in effect for north and east shores.

“Ocean front residents should be prepared for wave run up due to large surf,” civil defense says.