UPDATE: 11 p.m.

Forecasters have reduced the snow forecast for the summits of Mauna Kea and Mauna Loa to six inches, but a winter weather advisory is still in effect until 6 p.m. Tuesday.

The National Weather Service predicts wind gusts as high as 35 mph and snow levels between 12,500 and 13,000 feet. Earlier today, forecasters were predicting up to a foot of snow.

A flash flood watch remains in effect for the Big Island through Tuesday afternoon.

3:45 p.m.

The high surf advisory for east shores of Kauai, Oahu, Molokai, Maui and Hawaii island has been canceled.

“Surf along east-facing shores will remain elevated due to strong trades and large seas,” officials said.

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Hawaii’s sunny, breezy weather will turn much wetter starting tonight, with a foot of snow possible on Hawaii island summits, forecasters said.

The National Weather Service in Honolulu has issued a flash flood watch for the Big Island from 6 p.m. through Tuesday afternoon.

“Abundant moisture moving in from the southeast will bring the threat of flash flooding tonight through Tuesday afternoon for the Big Island,” forecasters said. “The greatest areas of risk will be over windward and mountain areas, especially the Hilo, Puna and Kau districts.”

The weather service issued a “hydrologic outlook” for the state, saying that “very moist air and a deepening trough aloft may bring periods of heavy rainfall to the state tonight through Wednesday.”

After hitting the Hawaii island tonight, heavy rain may spread to the other islands Monday, and possibly linger through midweek.

“Although some heavy rain is likely, the heaviest rainfall could pass by just to the south of the islands,” forecasters said.

A winter storm watch is also in effect from tonight through Tuesday afternoon, with heavy snow possible above 11,500 feet on the summits of Mauna Kea and Mauna Loa.

“Total snow accumulations over 12 inches possible. Winds could gust as high as 40 mph,” the winter storm watch said.

”If you are planning travel to the summits, monitor the latest forecasts and consider postponing your trip until the weather improves,” forecasters said.

They said that the strong high pressure northeast of Hawaii “will maintain locally strong trade winds over the islands through much of the coming week.”

A high surf advisory is also in effect today until 6 p.m. for east shores of Kauai, Oahu, Molokai, Maui and Hawaii island; north and west shores of Niihau, Kauai, Oahu and Molokai; north shores of Maui; and west shores of the Big Island.

Surf from 12 to 16 feet is expected for northern shores, and 8 to 12 feet for western shores. Waves of 7 to 10 feet are predicted for eastern shores today.