Climate Watch
By Rick Thoman Alaska Climate Specialist Alaska Center for Climate Assessment and Policy International Arctic Research Center/University of Alaska Fairbanks
We’ve reached the time of year when daylight is limited and what sun we see is too low in the sky to provide any significant heating. That means temperatures vary during the day in response to changes in winds and cloud cover but not to the sun.
One result of this is that daily high and low temperatures can occur at any time of day or night. On the monthly time scale, it means that ocean temperatures and sea ice — or the lack thereof — play an even larger role than during the spring and summer.
Periodic bouts of south winds in late October and November have resulted in somewhat less sea ice in the Bering Sea than is typical for this point in the season. November ends with some open water remaining in the southern Chukchi Sea. These factors are incorporated into NOAA’s Climate Prediction Center outlook for December, which calls for better than 50-50 chance for above normal temperatures and above normal precipitation for all of western Alaska.
The ongoing El Niño is also a modest factor in favoring above normal temperatures in western Alaska but more important in eastern Alaska. However, the chances of extreme cold in December are greatly diminished compared to years gone by, mainly due to later arrival of sea ice nowadays.
There has not been a December daily record low at Nome Airport set in the 21st century. The most recent December day to set a record low was December 13, 1998. In contrast, since 2000 there have been nine December daily record high temperatures set or tied.