Early-winter weather shifts are common on the Yukon-Kuskokwim (Y-K) Delta, but the National Weather Service said that December 2024 has been especially warm.
“Temperatures have been quite above average as of late," said meteorologist Josh Ribail with the National Weather Service in Anchorage. “The past couple of weeks, they've been around 10 to 20 degrees [Fahrenheit] above normal, and we've broken a few records as well.”
So far this month, two days have broken daily record high temperatures in Bethel, according to the National Weather Service. Last week, Ribail said that Bethel broke a daily high temperature record that had stood since 1932.
North of the Y-K Delta, it’s been even more starkly warm. Both Nome and Kotzebue broke all-time December record high temperatures less than halfway through the month.
Communities that shot to above-freezing stayed above that temperature for between a day and a half and three days. The warmer weather caused melting snow, baring ground, and the opening or widening of holes in river ice.
Ribail said that the unusually warm December weather is being caused by weather systems that bring up warmer air from the North Pacific, “and they can bring very unseasonably warm temperatures up, because they basically transport heat from the south and from the Pacific Ocean straight up all the way to Alaska.”
Typically, at this time of year, Ribail said that Northern and Western Alaska get weather systems coming from the opposite direction, from the Arctic or from Siberia in Russia, bringing much colder air. But when a pattern sets up like the warmer-than-normal pattern that’s been coming from the Pacific, Ribail said that those patterns can stick around.
“Early indicators seem at least that for early January [2025] and the rest of December, that this might be what we're looking at, something similar to what we've been seeing this month with this warmer pattern,” Ribail said.
With the weather outlook for the rest of the month tipping toward temperatures that could rise above freezing, Ribail said that communities in the Y-K Delta should be aware of the potential for dangerous weather events like sleet and freezing rain.
