Winter Storm Warnings

Winter storm warnings have been hoisted from the Yukon Delta and eastern Norton Sound to the western interior, as a decaying Bering Sea low joins forces with an Arctic trough to bring significant snowfall.  Here are snow forecast graphics from the NWS (click to enlarge):

Interestingly, however, the model forecasts have adjusted warmer for next week, with cold disappearing quickly by mid-week; warmth will quickly surge up from the southwest, replacing the cold air mass centered over northwestern Alaska.  Here are the latest 850mb temperature forecasts for late Tuesday, with cold poised to depart:

If warmer weather can stick around for the rest of the month, as seems possible, then thawing will start to make some headway.  Of course we don't want it to get too warm too quickly.

Here's a historical perspective on Fairbanks temperatures in previous years when La Niña transitioned rapidly into El Niño between winter and summer, as it is doing this year.

Interestingly, this set of "analog" years suggests that the odds most favor below-normal temperatures for 30-day periods ending late April through late May - or right around breakup season.  The median breakup date at Nenana for these 10 years is May 6, i.e. a few days later than normal.  However, not all ENSO transition years are cold around this time; two of the last three (1997 and 2009) were not, and Nenana breakup was on April 30 and May 1 in those years respectively.