Forecasting special events such as conflicts and epidemics is challenging because of their nature and the limited amount of historical information from which a reference base can be built. This study evaluates the performances of structured analogies, the Delphi method and interaction groups in forecasting the impact of such events. The empirical evidence reveals that the use of structured analogies leads to an average forecasting accuracy improvement of 8.4% compared to unaided judgment. This improvement in accuracy is greater when the use of structured analogies is accompanied by an increase in the level of expertise, the use of more analogies, the relevance of these analogies, and the introduction of pooling analogies through interaction within experts. Furthermore, the results from group judgmental forecasting approaches were very promising; the Delphi method and interaction groups improved accuracy by 27.0% and 54.4%, respectively.