Winter '10 / '11 - Stratospheric Warming - Take 4

Meant to post this over the weekend. Subsequent runs of the ECMWF have continued with the idea of a weakening polar vortex by month/s end suggesting a warming in the stratosphere with implications for cold temperatures toward the end of meteorological winter.

Note how the strong 85 m/s (~170 kts) PV in the left panel weakens to 35 m/s (~70 kts) by D+10 where the deep-layer blue highlights near 90°N indicates an east wind.  Favorable conditions are indicated for the Arctic Oscillation to fall well below zero in late February.

Not that significant warmth is expected anytime soon as the NAO ridge retrogrades toward Greenland and PNA remains positive with the most northern extension of the ridge reaching well above the Arctic Circle.  Short-wave energy migrating from this hi-latitude into the base of a deep eastern trough brings great potential to spin-up strong coastal storms off the SE CONUS.