Coming off the warmest year in Alaska history, the state’s largest city appears headed for the fifth or sixth coldest January in the local climate record.
That would put it between the 4.6 degree average of 1969 and the 5.1 degrees of 1956 in the Anchorage climate record at this moment, and the temperatures into next week are forecast to be well colder than normal.
The normal high for this time of year is 23 degrees with the normal low dipping to 11. The forecast highs through the weekend are significantly lower than the normal lows.
It’s almost like someone flipped a switch on New Year’s Eve when an unusually warm and rainy, Seattle-like like Anchorage transformed into something closer to cold and snowy International Falls, Minn.
Officials with the Chugach National Forest on the Kenai Peninsula south of Anchorage were Thursday warning recreationists of growing glaciers making trail travel difficult only a month after warning them to beware of thin ice because lakes had yet to fully freeze.
What a difference a month can make in Alaska.
“…Ice continues to grow and wreak havoc in many trail locations,” the agency’s trail report said. “Carter Lake trail glacier continues to grow at a half mile from the trailhead. Lost Lake trail in the first mile has numerous icy chutes that are quite slippery and sno-goes (snowmobiles) have found them.”
The glaciers the agency referenced aren’t the traditional kind formed by snow accumulations, but the kind built by overflow or “aufeis” glaciation, a regular seasonal event in Alaska.
Regular or not, it can be a headache as feet of ice accumulates.
“Because these white features that endure long into the green of summer are so striking, scientists have studied them for years,” writes Ned Rozell from the University of Alaska Fairbanks Geophysical Institute. “They have found that aufeis (German for “ice on top”) is often downstream of underground springs that gush all winter long.
“Many Alaskans know this ice as overflow. Its gradual buildup has created glaciers on Alaska roadways and has in midwinter forced people from cabins as their property slowly transformed into a skating rink.”
The skating-rink problem is what is now causing chaos on some Kenai trails despite the best trail-repair efforts of Chugach forest staff.
“A hundred feet of trail at mile 5 (of the Resurrection Pass Trail) had a landslide and is difficult passing on a sno-go with the glaciation that is building in this area and very little snow to build up tread around the slide,” reported trail tech Irene Lindquist. “If you travel on this section of trail be sure to have a buddy or two to help get down the ice and then back up on the trail.”
Meanwhile, she continues to warn of thin ice in places although Kenai Lake has finally frozen over fully. The ice thickness is increasing rapidly, but areas around inlets, outlets, seeps, pressure ridges and avalanche runouts remain potentially dangerous.
These risks will go down as the January deep freeze continues.
Color Alaska blue
The National Climate Center eight- to 10-day lookout issued today says there is a 70 to 90 percent probability that most of Alaska will stay frigid through Feb. 2. The federal agency seldom makes such bold predictions.
Probabilities are more often in the 50 to 60 percent range either colder or warmer. The chilly prediction this time seems to stem in part from a nicely stable arctic oscillation – that spin of air around the north pole famous for sucking warm, wet, “Pineapple Express” weather north from the mid-Pacific into Alaska and pushing cold, windy “Polar Vortex” storms into the American Heartland.
MIT scientist Judah Cohen, the vortex expert, believes a troposphere-stratosphere-troposphere coupling over the pole means the “arctic oscillation (AO) could remain predominantly in the positive phase for up to two months. Positive AO favors relatively mild temperatures for the Eastern U.S., Northern Europe and East Asia….”
When those areas warm, Alaska is usually cold, although not necessarily as cold as it is now. Cohen is expecting the coldest of the cold to focus over the Arctic east of Alaska. Some warmer air could then start to push north toward Alaska.
The Climate Center shifts its prediction come February:
“Probabilities for above-normal temperatures exceed 60 percent for the southern coast of Alaska and the Pacific Coast of the continental United States, consistent with the predicted impact of Madden-Julian Oscillation (MJO) related convective activity over the western Pacific. Probabilities of above-normal temperatures also exceed 60 percent for Northwest Alaska,” the center says.
The National Oceanic and Atmospheric Administration’s Jon Gottschalck describes the weather phenomenon this way:
“The MJO is an eastward moving disturbance of clouds, rainfall, winds, and pressure that traverses the planet in the tropics and returns to its initial starting point in 30 to 60 days on average. This atmospheric disturbance is distinct from the El Niño-Southern Oscillation, which once established, is associated with persistent features that last several seasons or longer over the Pacific Ocean basin. There can be multiple MJO events within a season, and so the MJO is best described as intraseasonal tropical climate variability (i.e. varies on a week-to-week basis).”
Newer Alaskans who’ve come to favor the warmer winters of the last few years over the cold winters of the past – those being more like this one – can always hope the MJO kicks a warm, wet El Nino-like Pineapple Express north to take the chill off the 49th state.