Question: How can one integrate the natural variation in the variables influencing fire propagation associated with the prediction of crown fire behavior? Conclusions: The present work highlights the advantage of incorporating the uncertainty in the estimation of the variables influencing the fire spread process to better assess the effect of nonlinear fire phenomena, such as the onset of crowning on free-burning fire behavior. The ensemble methods used not only enable an improved description of fire potential but also extend the range of questions that can be answered by fire behavior models, namely providing probabilistic outputs that can be linked to quantitative risk analysis.