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.
How to access S2S data efficiently?
In order to retrieve data efficiently users should follow instructions about S2S reforecasts retrieval efficiency.
Do you have any examples of S2S data retrieval scripts?
Find links here to efficient retrieval scripts for different S2S datasets via ECMWF Web API.