Meteorological winter (Dec-Feb) is about half over. It got off to the coldest start in years when the mean for December came in at 7.6 degrees below average. The mean temperature of 10.9 degrees was the coldest since December 1989 when the mean was only 9.2 degrees. January started out brutal. However, a mild streak over the last week has brought the mean temperature up. Through the 14th, the month is running 6.8 degrees below average. After the first week, January 2014 was almost 17 degrees below normal.
It appears that one of the big drivers of the cold has been the pool of warm water in the Pacific just south of Alaska (Image 1 above). In part, it has promoted the development of a big upper-level ridge just downstream from it along the West Coast (Image 2). This pattern has repeated itself over and over. There appears to be no end in sight to this set up. In fact, the American GFS computer forecast model still forecasts upper-level ridging over Alaska on the last day of this month (Image 3). This means that winter is probably far from over. While we will get mild spells from time to time (like the one we??ve just experienced), there still is a good chance of some very cold weather over the next couple of weeks.