Great to see another polar vortex blog, good luck!. I got growing interest in this subject during my PhD on solar/geomagnetic impacts on decadal climate variablity and I am now following forecasts/other blogs/twitter on a daily basis. What always frustrate me is my lack of  physical understanding on how the tropospheric wave pattern impact the polar vortex, e.g. wave breaking, wave interference etc. and under various stratospheric states. Likewise, the stratosphere doesn't always impact the troposphere/weather. Hope to see blog posts on this part during the winter season.