Which of the following indicates an inversion break or lift?

An inversion break or lift refers to the phenomenon where warmer air rises and breaks through a temperature inversion layer. A temperature inversion occurs when a layer of cooler air is trapped near the earth's surface by a layer of warmer air above it. During an inversion break, the less dense, warmer air (which can effectively be elevated) rises, leading to changes in the atmospheric conditions.

An increase in temperature signifies that the warm air is pushing towards or breaking through the cooler air below. This can disrupt the stable conditions created by the inversion, allowing for greater vertical air movement and potentially impacting fire behavior and weather patterns.

The other options—an increase in relative humidity, a decrease in temperature, and a decrease in air pressure—do not directly indicate the breaking of a temperature inversion. Instead, they often reflect more stable or even worsening conditions associated with an inversion. Therefore, understanding that an increase in temperature is indicative of inversion break or lift is crucial for predicting changes in fire behavior under varying weather conditions.