Pacific Storm Whips Hawaii With Rain and Snow, Causing Floods

(Bloomberg) -- Heavy rain has drenched the Hawaiian Islands, flooding roads and raising mudslide risks while sending loosened boulders tumbling down hillsides and bringing snow to the archipelago's highest peaks.

The two volcanoes on the big Island of Hawaii -- Mauna Kea and Mauna Loa -- are expected to get up to 4 inches (10.16 centimeters) of snow above 12,000 feet, the weather service said. The areas at the top of the towering peaks had snow during the weekend, and while that's a bit of a novelty it's not unusual to get accumulation there.

The Pacific storm could bring as much as 25 inches of rain in places across the island chain, said David Roth of the U.S. Weather Prediction Center. Maui already reported 12 inches and it's likely that just as much has fallen on the Big Island further south. The rain is coming from a system called a Kona low, which formed to the west of Hawaii and is drawing a long plume of moisture from an atmospheric river across the chain, Roth said. 

“This is the first one of the year,” he said. “Some years they don't get any, some years they get five or six.”

Atmospheric rivers are associated with heavy storms that often drench California and the Pacific Northwest, though Roth said this one won't be going that far east. These weather patterns were responsible for last month's damaging floods in Canada's westernmost province of British Columbia and in Washington State.

Hawaii's rains will continue as long as stream of moisture through the atmosphere continues to drag over the islands. Residents have been warned to stay away from “streams, rivers, drainage ditches, and culverts even if they are currently dry,” the National Weather service said.

“Do not cross fast flowing or rising water in your vehicle, or on foot,” a statement said.

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