On the same day , fire analysts stated that the Thomas Fire had been generating its own weather for the past two days , a behavior only observed in very massive wildfires and indicative of a firestorm . The Thomas Fire was generating massive pyrocumulus clouds , which were gathering heat from the flames below , although the unstable column of air could collapse at any time , which would generate sudden wind shifts near the fire and pose a major hazard to firefighters . This behavior had been previously observed during the massive 2009 Station Fire in Los Angeles . At this point , the Thomas Fire had become the fifth-largest wildfire in modern California history and the largest wildfire recorded in California in December . The Thomas Fire was also estimated to be at least the 10th most destructive wildfire on record in California
Station Fire
Station Fire (2009)
Thomas Fire