As Mainers endured the latest storm in a winter that just keeps on giving, mushers in Nome, Alaska, were coping with a dearth of snow.
Competitors in the Iditarod Trail Sled Dog Race, dogsled racing’s signature event, finished Tuesday on a thin coat of snow as the city 100 miles from the Arctic Circle coped with an unseasonably warm and wet winter.
There’s a connection, and global climate change may be playing a part.
The same weather pattern that left just 6 inches of snow on the ground in Nome this week brought Wednesday’s storm system to Maine, part of an unusually cold and snowy winter stretching from the Midwest to the East Coast and down into the Mid-Atlantic.
“In some winters you get a persistent pattern that keeps the storm track and everything the same,” said Alexander MacDonald, chief science adviser for the National Oceanic and Atmospheric Administration’s Office of Oceanic and Atmospheric Research. Instead of moving consistently west to east, sometimes weather systems shoot up north, bringing warm air from the unusually warm Pacific Ocean into the Arctic before dragging frigid air south and east, he said. Storms like Wednesday’s ride that roller-coaster across the country and into the Northeast.
The National Weather Service in Gray said a mix of snow and rain in Cumberland County would turn to snow after midnight, mixed with sleet by daybreak. By Thursday, as much as a quarter-inch of ice was possible on surfaces such as driveways and tree branches, making for a slow and hazardous commute in southern coastal Maine.
Thursday’s forecast calls for northwest winds of 20 to 25 mph gusting to 35 mph and wind chills as low as 3 below zero along the southern Maine coast.
The winter of 2013-14 seems to drag on and on. Portland had received 79 inches of snow before this latest storm, 27.7 inches above normal.
It all starts in the oceans, said MacDonald.
“There are winters where … (weather) flows almost west to east, from the Pacific all the way across North America. In recent years that’s been more common,” he said. “What we saw this year was a big portion of the north Pacific that was very warm.”
The resulting air mass traveled along a high-pressure ridge on the West Coast, up into Alaska, he said. “It brings warm air across the top, then down the polar express all the way down into the eastern U.S.”
Meteorologists call it the “Arctic oscillation” and it can play out across the globe, corresponding with torrential rains in parts of Europe and other abnormal weather patterns.
The extreme weather has raised questions of whether human-induced global climate change is to blame. MacDonald said it’s probably too early to say.
“We’ve seen this many times in the past,” he said, noting that several winters, including the winter of 1976-77, brought the same effect. Weather can have dramatic variations, whereas long-term changes in climate take years to assess to determine whether there’s a new normal.
“The idea that the warming Arctic results in some of these big, stormy, cold winters is a hypothesis. We don’t know enough about it yet,” he said.
A leading advocate of that hypothesis is Jennifer Francis of the Institute of Marine and Coastal Sciences at Rutgers University.
In a paper published in 2012, Francis and co-author Stephen Vavrus said there is evidence showing that rapidly rising temperatures in the Arctic are contributing to more extreme weather in areas to the south. Melting sea ice creates more energy in the atmosphere, increasing the likelihood that Pacific weather will track north toward the Arctic, then bring foul weather south, Francis wrote.
The volume of Arctic sea ice has decreased by 75 percent since the 1980s, according to NOAA.
It’s hard to point to cause and effect with something as large and complicated as the weather, MacDonald said. But he believes climatologists are becoming much better at forecasting extremes like this winter. “Our improvements in forecasting the ocean itself, those are what we think will lead us to a better forecast.”
David Hench can be contacted at 791-6327 or at: