Summertime -AO then -NAO

[AfewUniversesBelowNormal]

 

[raindancewx]

Some recent warm (Eastern) winter years like 2012 and 2015 had pretty big -NAO periods in MJJ on the monthly data -

2012   1.17   0.42   1.27   0.47  -0.91  -2.53  -1.32  -0.98  -0.59  -2.06  -0.58   0.17
2013   0.35  -0.45  -1.61   0.69   0.57   0.52   0.67   0.97   0.24  -1.28   0.90   0.95
2014   0.29   1.34   0.80   0.31  -0.92  -0.97   0.18  -1.68   1.62  -1.27   0.68   1.86
2015   1.79   1.32   1.45   0.73   0.15  -0.07  -3.18  -0.76  -0.65   0.44   1.74   2.24
2016   0.12   1.58   0.73   0.38  -0.77  -0.43  -1.76  -1.65   0.61   0.41  -0.16   0.48
2017   0.48   1.00   0.74   1.73  -1.91   0.05   1.26  -1.10  -0.61   0.19  -0.00   0.88
2018   1.44   1.58  -0.93   1.24   2.12   1.09   1.39   1.97   1.67   0.93  -0.11   0.61
2019   0.59   0.29   1.23   0.47  -2.62  -1.09