The Bristol Bay Times
The Bristol Bay Times

Cold air blob makes “full tour” of Alaska, prolonging winter weather across the state

A strong parade of storms has been making its way through the North Central Pacific Ocean, and the location of the jet stream has produced colder storms for Unalaska and the Aleutian region this spring. That’s according to Rick Thoman, a climate specialist at the International Arctic Research Center with the University of Alaska Fairbanks.

“Over the last six weeks, say, the Aleutians have been on the north side of the prevailing storm track, and so on the cold side of the storms,” Thoman said. “If the jet stream was say 500 miles farther north, it would still be stormy, but it wouldn’t be nearly as cold.”

Cold air from above the North Slope brought another round of wintery weather to Western Alaska, the Eastern Aleutians, Kodiak Island and into South Central as well, according to Thoman.

That was basically a blob of cold air that came down from the high Arctic from north of the North Slope, and it moved southwest through the Bering Strait down through the eastern Bering Sea, and is now actually moving into the western Gulf of Alaska,” he said.

While it has been a harsh spring for the region, these “blobs” are pretty normal for this time of year, Thoman said.

“As the high latitude atmosphere transitions from winter to summer, we get these little knots of cold air that will float around,” he explained. “Oftentimes, they will get stuck [in the] northern Bering Sea or northward and not move any farther south. But this one is doing the full tour.”

It even made a stop in Anchorage last week.


Late in the evening on May 8, the Anchorage airport got about one inch of snow. Thoman said it’s the third highest snowfall on record for this late in the season.

“There’s only been two other occurrences since the mid 1950s when there’s been more snow than that, May 8 or later,” he said.

Thoman said it hasn’t been a typical El Niño winter. Instead, there’s been what he calls a lot of “yo-yo weather.”

A week or two of cold weather, a week or two of mild stormy weather — and that is not characteristic of El Niño winters at all for Alaska,” he said. “El Niño winters tend to get stuck in the same pattern usually — especially for mainland Alaska — on the warm side.”

Thoman said these are transient storms and aren’t predictive of future weather or overall season conditions.

There is a mix of forecasts for summer in Western Alaska. NOAA’s Climate Prediction Center predicts an increased chance of higher than normal precipitation and low temperatures for Southwest Alaska. That includes the Alaska Peninsula, but not most of the Aleutians.

There are equal chances for above or below normal conditions for Unalaska westward, Thoman said.

The island saw some pretty calm conditions, even some sunshine, last weekend, but Thoman said a mild storm is working its way through the western Bering Sea this week.