For those who loathed or loved last winter’s non-wintery Alaska weather, climate scientists have an important message: There is a good chance of a repeat this winter.
Forces at sea, in the atmosphere and on land, both short-term and long-term, are combining to create what might be a perfect storm of heat for Alaska. That means another much-warmer-than-normal winter is expected for Alaska and northwestern North America.
“You might not want to buy that 70-below parka,” said Rick Thoman, the National Weather Service’s Alaska climate science and services manager and one of the scientists focused on winter even in the warm days of Alaska’s summer.
All of Alaska is likely to be warmer than normal in the next three months, according to the National Oceanic and Atmospheric Administration’s Climate Prediction Center. Probabilities of unusual warmth edge up to 80 percent in the Gulf of Alaska coastal areas. The outlook extending into the next year also predicts warmer than normal temperatures for almost all of the state, with similar heat expected in the Pacific Northwest and the West Coast.
The warmth has multiple sources: persistently high sea surface temperatures, which are expected to linger; a shift into a positive and warm phase of the cyclical Pacific Decadal Oscillation; a powerful El Nino that is developing in the Pacific; and wavy jet-stream patterns that bring warm weather north and cold weather south.
“That’s kind of in the background that everything’s projected onto. Every year, that background gets a little brighter, a little redder,” said Thoman, who prepared the Alaska section of the August/September/October forecast.
Such was the case with Alaska’s extreme winter of 2014-15, with average surface temperatures running above normal by 4 to 10 degrees Fahrenheit from December to February and, in Anchorage, a record-low snowfall.