Weather information with resolution needed to simulate fire spread is now easier for fire specialists to obtain. This will increase opportunities to use integrated weather/fire spread models for fire planning on wildfire incidents and prescribed fires. Care must be taken, however, to understand the error characteristics of the fire spread simulations generated by this approach. This study examines the space/time error characteristics of fire spread simulations generated using the MM5 mesoscale model and FARSITE, for a fire that occurred in San Diego County in June 2002. An accurate record of the fire’s growth was documented using a high resolution airborne imaging system developed specifically to observe wildland fires.