Which observation is NOT used when predicting flashover or backdraft potential?

When predicting flashover or backdraft potential, observations related to the conditions inside a structure are crucial. Building features provide insight into the materials present and airflow patterns, while heat indicators give firefighters information about the thermal environment, helping them understand the risk of a rapid fire spread. Smoke characteristics, such as color and density, can signal the fire's behavior and the likelihood of sudden ignition events.

Humidity levels, however, are generally not a primary factor in predicting flashover or backdraft. While humidity can influence fire behavior to some extent, it is less directly related to the immediate signs of impending flashover or backdraft compared to the other observations. Flashover and backdraft predictions rely more on thermal indicators and smoke behavior than on atmospheric conditions like humidity.