Return of Hi-Latitude Easterlies

Note the ECMWF/s D+8 forecast for the return of deep tropospheric...hi-latitude easterlies over the pole suggesting a return of a negative AO index toward the end of DEC.

The time-height section also shows the 70mb mean zonal wind from the east over the Equator...indicating the negative QBO.

Negative QBO favors a negative AO...which is associated with a less stable...and slower polar vortex. These conditions present good opportunities for arctic outbreaks....storminess...and the potential for hi-latitude blocking.