Fig. 3: Timeseries of high-latitude blocking and the NAO and the respective skill maps.
From: Decadal predictability of North Atlantic blocking and the NAO
On the left: predicted and observed standardized timeseries of HLB (a) and the NAO (c). The red, dotted lines show the CESM-DPLE ensemble mean for the lead-year range LY[1–8], while the solid, red lines represent a smoothed version of the former using centered 7-year running average. The blue lines show the observations (NCAR/NCEP reanalysis). As expected, the HLB and NAO timeseries are highly anticorrelated (−0.95 for NCEP/NCAR), while the respective anomaly correlation coefficients (ACC) are 0.65 and 0.59, both for the predicted timeseries without smoothing. On the right: mapping of the predictive skill (ACC) for blocking (b) and MSLP (d) winter-mean anomalies averaged over the same lead-year range LY[1–8]. The blue frame in b as in Fig. 1, while the blue lines in d, at 35 °N and 65 °N, relate to the definition of the NAO index (Methods). The dots on the maps indicate statistically significant correlations (Methods).
