Winter '17 / '18 - Sudden Stratospheric Warming: Watch #1

Something worth keeping an eye on ...

 

D+10/s polar vortex splits in two with action centers over northern Canada along ~90W and ~45E INVOF the Black Sea.

 

Deep layer ... high latitude flow reversal (negative / blue values into the board i.e., east wind / anticyclonic circulation) would provide highly favorable conditions for a negative Arctic Oscillation index over an extended period toward meteorological winter's end.