The ensembles members are obtained by lagged runtimes depending on release date. There are 12 release dates, corresponding to the 15th of each month. The members for the mid-january 1982 are the following runtime:

Thus the runtimes for the 12 release dates, on each year, are indicated in the tables below (the default 16 initializations defining members are indicated in boldface, as taken by the R package for data access. Note that due to some missing initializations in the original dataset, the configuration of the default members taken through the R interface is not directly the 16 first initializations of the corresponding lead month, but the 16 first complete initializations (i.e., available for all years in hindcast).

In particular, the missing initialization times are indicated with asterisks in the table (* or **), and the specific location of the missing runtimes indicated in the rightmost column. As a result, the total number of selectable members varies depending of the lead month chosen (this is indicated by n in the tables below). These are selected in R through the members argument of the function loadECOMS that can take any integer value from 1 to n for each particular lead month, corresponding this value to their relative order in the tables below (and excluding the members marked with asterisks).