After a cold October, a warm November, a cold December and early January, a January thaw set in on its normal third week of January schedule. We promised the cold would be back and it returned in week 4. The cold spells related to stratospheric warmings favored in east QBO low solar years and in years following high latitude volcanoes like we saw in Redoubt, Alaska and Sarychev, Russia. The following link will provide an illustration of the degree to which this phenomenon has blossomed in the past several weeks.