Definitely something to be concerned about. Have to see if it's a trend, though. Europe saw some pretty intense cold snaps over the past decade (2012, 2013, 2017). If a winter like this occurs three years in a row, then we know that something is really up. I find that nature is always searching for equilibrium, or balance. It will be interesting to see if, in 2021 or 2022, central and eastern Europe get an intense cold snap similar to 2006 to balance this out. Note how warm winters were in Alaska over the past decade only for them to see intense cold this year.