Researchers have identified a wildland fire behavior phenomenon that is a little scary–fingers of fire that shoot out from the main flaming front at 100 miles per hour, or 147 feet per second. These fingers can be tens of feet wide and can extend for hundreds of feet, but then they collapse, all within two seconds.
Shaded contours show the temperature detected by the infrared imager. The vectors show the calculated flow velocities. Every eighth point in the x direction and every fourth point in the z direction are plotted.Janice Coen, Shankar Mahalingam, and John Daily observed this behavior on infrared imagery of going fires and described it in their paper, Infrared Imagery of Crown-Fire Dynamics during FROSTFIRE, Journal of Applied Meteorology, 43, 1241-1259.
According to the report:
This powerful, dynamic mechanism of fire spread could explain firefighter reports of being overtaken by ‘‘fireballs.’’
