The relative variation in predicted fireline intensity and the wind speed thresholds for the onset of crowning and active crown fire spread in a lodgepole pine (Pinus contorta Dougl. ex Loud.) stand subjected to a commercial thinning operation were examined. This involved seven distinct scenarios, each with different assumptions regarding fine dead fuel moisture contents and fire behavior models. This case study illustrates that widely varying results can be expected, depending on how the environmental inputs are handled and which fire behavior characteristic is analyzed.