I plotted up the temperature analysis to show how Boston--and pretty much the entire northeastern US--enjoyed a warmer Christmas in 2015 than Los Angeles. Bad Dad pointed out that this is a junk graphic because everyone already knows this.
In fact, when I plotted up today's near surface temperature analysis in polar stereographic, you can see that the north pole almost got above freezing! Moreover, it exhibits a wavenumber of 2.
AER's Arctic Oscillation Analysis and Forecasts page gives a technical explanation of this event.