In a previously published study (Cohen & Jones 2011), an index describing the increase of Eurasian snow cover during October (Snow Advance Index, SAI) has shown to be associated with the Arctic Oscillation (AO) in the following winter (DJF). Based on this finding, we demonstrate that a modified version of the October SAI is highly correlated with the DJF-mean North Atlantic Oscillation, as well as with the concurrent values for precipitation, insolation and wind speed over Spain. Exploiting this formerly unknown lagged teleconnection, a statistical forecasting scheme is applied to predict the above mentioned variables one month ahead. The hindcast skill obtained from a one-year out cross-validation considerably outperforms the results of any competing dynamical and empirical forecasting approach available to date.
Brands S, Manzanas R, Gutiérrez JM, Cohen J (2012): Seasonal Predictability of Wintertime Precipitation in Europe Using the Snow Advance Index. Journal of Climate 25:4023-4028
Cohen J, Jones J (2011) A new index for more accurate winter predictions. Geophyiscal Research Letters 38:L21701, doi:10.1029/2011GL049626