From Weather5280.com (Brendan Heberton):
The Pacific Decadal Oscillation (PDO) index broke the record for highest positive ever recorded during the month of December in 2014. At 2.51, this is also the highest value since August of 1997 according to NWS Albuquerque. Below is a chart of all December PDO indices since 1900, this past one well above any other (far right).
