RE: 1996
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Every year is a little different, and Nov-March 1995-6 (winter of 1996) also has other differences like a non-zero third mode, but if I look for a trough along 35N in the W. Pacific, a ridge over the Bering Sea, and a trough over the eastern half of North America, I see those anomalies then. A weak ridge also appears centered over California. The winter of 1997 (Nov. 1996- March 1997) has the Pacific and California features, but the ridge does not extend down the West Coast and the trough over North America is not well developed. Other years that appear to have this pattern are 1991, 1994 and 2003, but none as dramatically as 2014. It is also possible to find years that have this pattern with the opposite polarity, 1995, 1999, 2000 and 2006, to varying degrees, and just by eye, nothing quantitative. You have to bear in mind that the correlations between the NPM and the monthly mean height field in winter are only about 0.3, so the fraction of variance explained is small.