In the article the scenario thinking as a way of social forecasting is discussed in the context of social diagnostics. Deficiency of scenario thinking in Russian society impacts negatively the quality of management decisions and dynamics of public moods, while sociological diagnostics increases reliability and validity of the findings simulating future on the basis of monitoring the state of the phenomena and processes under study. Sociological diagnostics demonstrates cognitive potential of scenario thinking as a sociological imagination tool for learning and assessing processes in Russian society. This mechanism fills gaps associated with inconsistency of the obtained results for diagnostics. Sociological diagnostics contains a set of analytical procedures describing current state of the diagnosed object, identifies prospects for development and transition to a different qualitative level: modification and transformation. Outside the sociological diagnostics there are certain fields of social tensions, possible transition from the state of social apathy or negative mobilization to the scenario of crisis. As part of the sociological diagnostics we should consider actual social situation as a situation of multiple alternatives containing the possibility of positive change and covering all aspects of social life, or deeper crisis characterized by the fatalism stance.