Winter '14 / '15 - Weakening Polar Vortex ==> Sudden Stratospheric Warming: UPDATE 6

OBS
The current sudden stratospheric warming (SSW) event has likely peaked as evidenced by
1)   the deep layer wind reversal of the polar vortex (PV) and
2)  a dipole of hi-latitude warming maximized INVOF eastern Greenland.

Image:  10-hPa temperature change in a week in the Northern Hemisphere (courtesy Tokyo Climate Center, Climate Prediction Division).  The contour interval is 5 °C. The pink and light blue shadings indicate warming and cooling, respectively. The red shading denotes warming for values higher than 25 °C.

Upper air analysis courtesy University of Wyoming, College of Engineering, Department of Atmospheric Science

---
Deep-layer hi-latitude easterlies ~30 KTs.

 

 ---

Arctic Oscillation (AO) poised to tank by mid-month.

 

 

D+11 prog of a near-perfect AO tri-pole and a stationary... four-wave pattern.

AO loading pattern

 

 

---

Bonus OB:  DEC QBO dipped to -25.35.