A month behind schedule, winter is finally forcing its way into a coastal Alaska coated in frozen rain.
Temperatures on the west side of the Kenai Peninsula and in the Anchorage metropolitan area were dropping into the teens and single digits on Saturday. Four hundreds miles to the west where the lower Kuskokwim River had remained strangely free of ice through December and into January, the thermometer was falling toward zero.
The National Weather Service warned of windchills to 40 degrees or colder on the wild Yukon-Kuskokwim Delta by Sunday night. The 49th state was at last returning to something near normal, although normal is getting harder to define in a period where the drum beat of climate change dominates weather discussions.
After a December 7.5 degrees above normal, January was tracking more than 8 degrees warmer, and though a late-arriving cold snap is expected to bring the average down, it seems probable that January 2018, like December 2017, will end above average.
Still, if the experts are correct, it does look as if the state will see more of winter from here on out.
Sea ice is growing in the Bering Sea and has now surrounded Saint Lawrence Island, though the ice remains far north of where it should a month after National Snow & Ice Data headlined its year-end report “Baked Alaska and 2017 in review.”
On the Kenai, though the temperatures are moving back toward normal, snow conditions are nothing like what Alaskans have come to expect. The Kenai is usually a snowy, winter playground for the residents of Alaska’s urban core, but not this year.
December rains washed away lower elevation snow. Only a tiny part of the Chugach National Forest at and above Turnagain Pass at 900 feet in the Kenai Mountains is open to snowmachine riders, and even there, forest officials are asking people to “please avoid riding on ‘Rookie Hill’ and other areas with exposed vegetation.”
Above about 1,500 feet, the precipitation that had been falling as rain at lower elevations has fallen as snow in the Kenai and Chugach mountains of the coast, but there are few roads that climb that high in Alaska.
Forest technician Irene Lindquist said the Chugach forest appeared to be on it way to the latest snowmachine opening in recent history. There were snow “showers” in the forecast for the week ahead, but no significant amounts of snow predicted before who knows what Mother Nature throws next at most Alaskans. The majority of the state’s population lives in the Anchorage metro area.
The national Climate Prediction Center which last year was predicting a colder than normal winter for the 49th state is now calling for February temperatures near normal for the state’s urban core, colder temperatures in the Panhandle and along the Canadian border, and continuing warmer temperatures in Western Alaska.
A La Nina is bringing cold, deep ocean water to the surface of the eastern, equatorial Pacific Ocean with a resulting decrease in sea surface temperatures. The interactions of ocean water temperatures, land mass temperatures in North America, and weather systems controlled by the corresponding changes in air pressure get complicated here, but the simple versions in this:
Under La Nina conditions, the jet stream flows straight across the Pacific Ocean and carries a lot of moisture into California. And under El Nino conditions, the jet stream tends to get bent north, as it has been regularly earlier this winter, to push that wet, warm air into Alaska.
There are some theorizing that steadily warming Arctic Ocean waters are also playing a role in shifting the jet stream and might have been responsible in part for what was happening in Alaska this year.
Only time will tell how good that theory. Meanwhile, El Nino and La Nina will continue to play big roles.
“Based on the latest observations and forecast guidance, forecasters believe this weak-to-moderate La Niña is currently peaking and will eventually weaken into the spring,” the climate center says.
That would point toward a normal May, June and July for Alaska, but as those who’ve lived here long know, normal operates within a wide range in the north.