Winter '12 / '13 - Arctic Oscillation: Day 31

Not sure what if anything it means but here/s the state of the AO on Day 31 of meteorological winter during its 63 year period-of-record. 

Blue line is the observed AO on 31-DEC.

Red line is a 9-point binomial filter.  The filter removes noise from the signal to highlight trends.

The 31-DEC-12 AO ranks 31th (52th percentile). 

Same idea for AO/s sister...the North Atlantic Oscillation (NAO).

The 31-DEC-12 NAO ranks 53th (84th percentile).