The National Weather Service office on Oahu in Honolulu, Hawaii has issued a Winter Weather Advisory for portions of the Big Island of Hawaii for today into tomorrow morning. While the calendar says it’s mid-May and the map says it’s the tropics, the expected snowfall isn’t as rare as one would think it would be.
While most people don’t associate the tropical paradise Hawaii is known for with snow, they’re surprised to learn that it does snow in the winter due to the elevation of the volcanic peaks on Hawaii and Maui islands. Mauna Kea is the highest of the bunch at 13,803 feet. Maui’s Haleakala is much lower at 10,023 feet. Because of that difference, Hawaii Island will see snow more frequently than the lower Maui Island. Just one storm in January 2020 dropped 2-3 feet of snow on Hawaii Island and created snow drifts that were far deeper. Another storm in January 2021 brought snowboarders and skiers out to the mountain by the dozens. A blizzard hit the Big Island last December, guaranteeing a White Christmas there for 2022 just 5 months ago. And while snow during the winter months is most common, due to the high altitude of the state’s highest peaks, snow is possible in any month of the year.
A disturbance moving through the state is responsible for the snow. Yesterday, moderate rain fell over portions of Kauai and Oahu, eventually spreading into Maui last night. Heavy rain hit the Big Island today, triggering the issuance of a Flash Flood Warning for South Kohala including the Waikoloa Village area. Heavier showers and possibly even an isolated thunderstorm are possible through the afternoon at lower elevations while periods of snow will fall on the highest elevations of Hawaii Island.
According to the National Weather Service, easterly trades will try to make its return to most areas by Saturday afternoon but scattered showers are still expected throughout the state due to lingering low level moisture. Trades will further strengthen Sunday into Monday with our typical breezy trade wind weather returning.
For now, a Winter Weather Advisory is in effect through 6 am local time in Hawaii on Saturday. Periods of snow and low visibility can be expected, with snow accumulations of 1-3″ possible on the Big Island summits of Mauna Loa and Mauna Kea. “Plan on slippery road conditions,” the National Weather Service cautions, adding that a “winter weather advisory means that periods of snow, sleet, or freezing rain will cause travel difficulties. Be prepared for slippery roads and limited visibilities and use caution while driving.”
For the safety of drivers, there really aren’t any places open where people can ride through the wintry conditions. The Rangers at Mauna Kea closed the road earlier today, stating, “The Mauna Kea Access Road is closed to the public at the Visitor Information Station due to hazardous driving conditions including fog with visibility less than 50 feet and icy road conditions. Hail, sleet, and snow are falling at the summit causing slippery road conditions. Rangers will monitor the road and weather conditions throughout the day and will reopen the road once the conditions are safe.