What does a wide "V" pattern at the base of a fire indicate?

A wide "V" pattern at the base of a fire is indicative of the fire's spread and intensity. Specifically, this pattern forms when the flames spread outward and upward from a single point of origin, creating a shape that resembles the letter "V." As the fire burns, the brightness and heat increase, which causes the pattern to become wider as it moves higher from the base.

This phenomenon occurs because the flames draw in additional fuel and heat, allowing them to grow larger. The width of the "V" at the base represents the area closest to the ignition source, where the flames were most concentrated before spreading. In contrast, the patterns formed by a fire that was controlled quickly or that originated from multiple sources would typically appear different, with more uniform or non-linear features reflecting their extinguishment process or ignition sources.

Thus, the observation of a wide "V" pattern suggests that the fire steadily increased in intensity over time as it spread through available fuel, confirming the correctness of that particular answer.