Rapid Changes

Alaska's roller coaster of temperature swings this winter has produced another dizzying change in recent days, with widespread warmth enveloping much of the state since Monday.  The warm-up was very dramatic in western Alaska and brought a sudden end to persistent cold in the northwest.  In particular, Kotzebue had been stuck in a cold pattern since late January; minimum temperatures were in the -30s F for a week recently, but the past two days have seen above-freezing temperatures.

On a statewide basis, the handy index from UAF shows the episodic swings between colder and warmer, relative to normal, since autumn.  Overall, cold episodes have been more persistent and more unusual than the warm spells, although cold seems to be losing traction: the most recent cold period was less pronounced than earlier episodes (although not in northern Alaska).

Higher than normal variability of temperatures is a typical feature of La Niña winters - see this earlier post on this point:

https://ak-wx.blogspot.com/2016/02/lack-of-cold-and-low-variance.html

Here's a sequence of model-estimated daily temperature anomalies over the past week or so.