While it may seem counterintuitive to mainlanders, Hawaii gets snow every year. The peaks of Mauna Kea, Mauna Loa and Haleakala, reaching 13,796, 13,679 and 10,023 feet respectively, are hit with flurries every year.
More rare, however, is thundersnow, which is what Hawaii saw earlier this month. Mauna Kea, a dormant volcano and the state's highest peak, was hit Dec. 18 by "significant snowfall with continuous thunder and lightning," according to the National Weather Service.
So, while residents and visitors in Hilo were enjoying pleasant 75-degree weather, thundersnow at the peak of Mauna Kea was causing treacherous conditions for researchers who man scientific stations on the volcano.
The mix of meteorological elements needed for thundersnow is so rare that scientists have estimated only .07% of snowstorms are accompanied by thunder.
The ingredients for thundersnow are a mass of cold air sitting on top of warm air, and more humid air closer to the ground. For it all to add up to thundersnow, the layer of air closest to the ground has to be warmer than those above, but still sufficiently cold to create snow.
Snow rarely appears below 9,000 feet in the Hawaiian islands. Earlier this month more than a foot of snow fell on Mauna Kea and the road to the summit was temporarily closed, according to the National Weather Service.
While skiing is possible at Mauna Kea, it is for experienced skiers only, as the terrain is ungroomed and there are no ski lifts.
"Mauna Kea is a National Science Reserve and is not maintained as a ski area. Skiing areas may have unmarked and exposed rocks. ... Most runs are for intermediate to advanced, skiers/snowboarders," the Mauna Kea Ski Corp. advises.