ANCHORAGE, Alaska (KTUU) - The Climate Prediction Center has put out its fall forecast and Alaska is expected to tilt toward warmer than normal.
North and northwest areas of the state have a 65 to 75 percent chance of having above average temperatures. A strip from northeast Alaska through the Interior and down to Southwest/Aleutians has a 55 percent chance of warmer than normal temperatures. Southcentral and Southeast are still expected to see above average temperatures but it’s only a 45 percent chance.
According to Rick Thoman, Climate Science and Services Manager for the National Weather Service, Alaska Region, there are a number of factors influencing the forecast, including warmer than normal sea surface temperatures in the Bering and Chukchi Seas as well as a developing El Nino.
El Nino is created when there are warmer than normal sea surface temperatures in the equatorial Pacific. For it to be considered an El Nino, the sea surface temperatures have to rise more .5 degrees Celsius or about .9 degrees Fahrenheit above the normal temperature. Though it occurs in the tropics, it impacts weather across the Pacific Ocean and United States, including Alaska.
When an El Nino pattern occurs, winters in Alaska, particularly southern Alaska, tend to be warmer than normal. The question for many winter outdoor enthusiasts is: What about the snow?
“El Nino winters do favor significantly warmer than normal temperatures,” says Thoman. “But because snow is so episodic, there's a less strong connection. We certainly can have big snow storms, but if it's persistently warm, at least in low elevation Anchorage, there's always the risk of melting off much of that snowpack.”
The last occurrence of a strong El Nino happened during the winter of 2015-2016. From September through March, Anchorage received 38.3 inches of snow at the National Weather Service Forecast Office. Glen Alps saw 107.0 inches of snow and Valdez received 119.7 inches.