If you’re in the Lower 48 looking for snow, may I suggest a trip to Hawaii? While a good chunk of the U.S. suffers under a snow-killing heat dome, Hawaii is in for a real-deal blizzard.
The National Weather Service issued rare blizzard warnings for the highlands of the Big Island on Friday as a powerful storm plows into the island chain. The forecast would be gnarly even if it weren’t in the tropics. But in the paradise that is the Big Island, it’s downright incredible.
“Travel could be very difficult to impossible,” the NWS Honolulu office warned. “Blowing snow will significantly reduce visibility at times, with periods of zero visibility.”
The high reaches of the Big Island could see “12 inches or more” according to the agency, and winds will gust more than 100 mph (160 kph), stats that would put even the most fearsome nor’easter to shame. The forecast for the summit of Mauna Loa, the highest point in Hawaii, calls for wind gusts to reach an astounding 160 mph (258 kph). For reference, Category 5 hurricane winds are 157 mph (252 kph) or higher. Wind chill values at the summit will drop to minus-3 degrees Fahrenheit (minus-19 degrees Celsius). The summit isn’t accessible by car, but the passes that cut through the heart of the Big Island will still be plenty dangerous.
“If you must travel, have a winter survival kit with you,” the NWS warned in language that, again, is for Hawaiians. (If you don’t know what’s in one, here’s a handy guide from our pals at Lifehacker.)
Webcam imagery from the top of Mauna Loa shows snow already on the ground. Volcanoes National Park closed summit access to Mauna Loa until at least Wednesday, indicating that the trails that head there are likely going to be impassable for quite some time. In short, it’s about to get real.
While the intensity of the forecast and snow warning language are striking, so, too, are the NWS alerts in place for lower elevations. The Big Island along with the neighboring islands that make up Hawaii stretching to the northwest are under a slew of high wind, surf, gale, and flood warnings and watches. The NWS is calling for “significant flooding” and risks of landslides on every one of the Hawaiian islands, underscoring how widespread and vigorous the system is. High surf advisories are also in place with waves expected to reach as high as 35 feet (11 meters) that will make going anywhere near the beach a dangerous proposition as well, particularly north-facing shorelines. Some roads are already closing on the Big Island. Basically, this is stay-put weather you don’t want to mess with.
The storm system that will bring all this wild weather is what’s known as a “Kona low.” Here’s a nice breakdown from Capital Weather Gang of what makes a Kona low different from an average storm system in the area:
Prevailing winds over the islands are usually out of the east and northeast, but Kona lows draw in winds from the southwest, tapping abundant moisture.
This particular Kona low is predicted to be slow-moving, forming west of Kauai over the weekend and lingering into early next week.
Snowfall isn’t unheard of on the Big Island’s summits, which include Mauna Loa and Mauna Kea. Both volcanoes reach more than 13,000 feet (3,960 meters) above the Pacific beaches that ring the island. Having visited Mauna Loa Observatory, located on the volcano’s flanks, I can confirm that it gets nippy. It was puffy jacket weather even on the average November day I was there in 2019. Just this January, snow fell on Mauna Kea.
But the storm system that will roar over the island chain this weekend is on another level. Obviously heed all warnings and road closures if you live there. And if you’re not there, enjoy the scene from afar. Because right now, the mainland U.S. is in dire straits when it comes to snow. Just 6% of the Lower 48 has snow on the ground as of Friday. Mountain towns in Colorado are starting to freak out with a paltry snowpack to start ski season.
Where precipitation has fallen, it’s failed to do so in frozen form; the Pacific Northwest has been hammered by a series of storms (ironically, those storms tapped moisture from as far away Hawaii), but they arrived with a blast of warm air. That means that instead of snow, high elevations saw rain—and lots of it. Given the amount of snow that’s about to fall in Hawaii, it sounds like the islands could have some to spare, though. Now if only we could figure out how to get it to places that actually need it...
Update, 12/4/21, 11:56 a.m. ET: This post has been updated with the latest forecast information and resources.