A filament of the Stratospheric Polar Vortex is predicted to extend down across the North Pacific/Alaska. This is likely aiding in highly anomalous (sub 300m below normal 500mb geopotential height anomaly) deep upper-level cyclone over the Aleutian islands this week. pic.twitter.com/rCnBXKw1Ks

— Mike Ventrice (@MJVentrice) January 28, 2020