ALT Screenshot of a National Weather Service report. Highlighted is a section that says "the heat combined with lingering instability has brought deep mixing heights up to 16,000 feet today, leading to an elevated risk for arratice plume-dominated fire behavior.

ALT A table showing fires that occurred with mixing heights of 10,000 to 15,000 feet, and sometimes as high as 20,000 feet. Acres burned range from 31,000 (Lake fire) to 240,000 (Zaca fire).

ALT Illustration showing how mixing promotes larger fires. The summer sun heats the land surface, which causes warm air near the surface to rise. Where that air cools with altitude, it sinks back to the surface, heating through compression. Days with higher mixing heights promote larger fire growth.