I always love plotting HYSPLIT trajectories when there's a "Siberian Express" event like this one, where high-latitude blocking near Alaska seeds N America w/ extremely frigid air from Siberia.

Western Canada & the NW 1/3rd of the US are going to turn brutally cold next week 🥶 pic.twitter.com/6HbIai9peo

— Eric Webb (@webberweather) October 31, 2022