This paper proposes a novel methodology to identify congestion problems under both "traditional" and "new" uncertainties such as generation costs, location and size of new generators, retirement of old ones, generation patterns, etc. The methodology allows not only identifying the transmission paths and corridors which will have congestion problems, but also the scenarios producing these critical situations. Thus, it can be used not only to simplify the study of new investments (reinforcement of existing lines), but also to facilitate the evaluation of hedging strategies and the design of proactive policies to avoid the detected congestion.