Why I cannot access the most recent data?
Because of the agreed data policy with the data providers, the S2S realtime type of forecast can be accessed only with 3 weeks delay. There should not be any such restriction for the reforecasts.
What are reforecasts?
Reforecasts are forecasts run using the same model version as real-time forecast for a number of past dates. More details here.in A brief description of reforecasts
How to access S2S data efficiently?
...
Do you provide analysis in S2S?
In principle the The S2S database does not contain the initial conditionsthe analysis used to initialize the S2S models. However, for some models (e.g ECMWF) step 0 is available (see details below), but only for instantaneous variables. For some models (e.g. ECMWF), step 0 of the control forecast corresponds to the unperturbed analysis.
If you are interested in re-forecasts, most re-forecasts are initialized either from JRA, ERA or NCEP re-analysis which can be available from other public datasets.
...