The Arctic Index (AO) reached 4.317 on 16-NOV...the third highest November value for the period of record (1950 - current). Record high of 4.544 was set in 1979 followed by 4.444 in 1995.
Does this event offer any insight into the character of the upcoming winter?
QBO is correlated with the strength of the Polar Vortex (PV)
QBO-W (+) ==> strong PV ==> +AO
QBO-E (-) ==> weak PV ==> -AO
QBO-2013 is currently west (+)...has probably peaked...and will likely flip toward the end of the '13 / '14 winter.
QBO was wicked east the winter of 1979-80 and had just flipped into its easterly phase NOV-95.
MEI ESNO-79 was warm and cold in 1995. La Nada is forecast for ENSO-13.
Chart: 30-day moving averages for AO...NAO...and PNA (SEP-11 through NOV-13).
Daily index data here.