 By this time, the Thomas Fire had grossly surpassed the size of the previous largest fire in December, which was extremely unusual.Fire officials noted that many areas had been "Moonscaped", an event in which the brush has been so completely burned that it was left looking like a barren and blackened landscape, resembling the surface of the Moon, which is indicative of extreme fire behavior.During the evening of December 11, the Thomas Fire expanded further to , while firefighters increased containment of the fire to 20%.