anomalies of the WTs during the periods leading up to the five
most severe droughts as compared to the average frequency of a given WT for the same
period of the year over the entire data record. A period equal to dreg preceding the drought
plus the 20 first days of the drought was used. All WTs with a net positive frequency anomaly
over the five events were considered to be associated
/media/ces/ces-oslo2010_proceedings.pdf