Analysis of propagation of complex fire: case of the Yarnell Hill Fire 1

We examine the propagation of the Yarnell Hill Fire in Arizona, June 28 -- July 3, 2013 to assess the nature of its complexity. We identify the critical fire growth that starts about 35 hours after the fire initiation. In a time span of three hours, the fire area is doubled. Within the following four hours, the direction of fire turns by about 180 degrees. An hour later, a pyrocumulonimbus cloud is observed above the fire area. To monitor complex fires, we propose implementation of an IR instrument to scrutinize fire remotely for behaviors, such as vortices and rotation, arising from combustion events, terrain characteristics, and outside influences. We propose a small reconnaissance plane circling to the side and above the fire area to search for anomalies in fire propagation and atmosphere during the fire consolidation during the initial 45 hours. Ideally, the observing instrument would be sensitive in IR region at about 4.5 microns where carbon oxide emits and water transmits the radiation.