Sudden stratospheric warming

After an unusually mild November and December, the new year has finally brought real winter temperatures and ice to the lake. Right now it is -13 degrees outside and, unlike last winter, the temperature is expected to remain below freezing for the entire 14 day forecast window. Thanks to our nuclear-powered heat pump, it is still warm and comfy inside as I read up on how the polar jet streams work and how their sudden breakdown in the winter may lead to colder surface temperatures as the ones we are experiencing right now. Though the phenomenon as such is natural, anthropogenic climate change is likely to have complex interaction effects that may lead to more extreme weathers, including prolonged cold spells.