|Bull moose rests in a snowdrift in Anchorage, Alaska [AP]
Snow in Alaska is rarely newsworthy. The bulk of the U.S. state lies north of 60 degrees latitude and winter arrives early and leaves late. But the snowfall of winter 2011/12, even by Alaskan standards, has been remarkable.
After having endured the snowiest winter in 60 years, residents of Anchorage were entitled to believe a change in fortunes was due with the arrival of spring. Instead, heavy snowfall has seen the seasonal total surpass the record set back in the winter of 1954/5.
That record of 337cm was broken on Saturday when another fall of 9cm took the total to 339cm.
Between 30 and 60cm of that total were dumped in what was dubbed a ‘snowicane’ in late February as Nome bore the brunt of an exceptionally deep depression’s 140kph winds.
The impact of the extreme weather on life in Alaska has been considerable. During the peak of the winter weather, the town of Cardova was under as much as six metres of snow. In many communities snow-walled canyons lined streets and older, flat roofed buildings collapsed under the weight of the snow.
Headline writers had a field day with variations on ‘moose on the loose’ as scores of the deer left the mountains east of Anchorage and headed into town foraging for food.
Moose, which can stand as high as two metres at the shoulder and weigh as much as 700kg, have voracious appetites, consuming up to 20kg of food. They strip trees of bark and cause considerable damage.
Their great size makes them a hazard to motorists and whilst many of the animals are likely to have starved to death during the harsh winter, many more have been killed in collisions with motor vehicles.
Snowfall across Alaska is closely related to La Nina but the Arctic Oscillation (AO) is believed by meteorologists to be a contributing factor.
The AO is a measure of the surface atmospheric pressure pattern within the Arctic region. When the AO is in a positive phase, surface pressure in the Arctic is low.
This encourages the westerly jet stream winds in middle latitudes which, in turn, restrict the coldest air to the Arctic.
Currently, however, the AO is negative, meaning that pressure is high in the Arctic region. This has caused the jet stream to move southwards and weaken, allowing the penetration of cold Arctic air to hit Alaska.
It may be a little premature to predict the end of the snow for Alaska. Forecasts do suggest sunnier skies and warmer weather on their way over the next few days. For many Alaskan residents an improvement in weather conditions cannot come soon enough.