High temperature and high relative humidity typically result in what atmospheric condition?

High temperature combined with high relative humidity generally leads to low atmospheric pressure. This relationship is primarily due to the physical properties of air and how temperature affects its density.

When temperatures rise, the air expands and becomes less dense. This expansion decreases the overall weight of the air above a given area, which contributes to a reduction in atmospheric pressure. Moreover, high humidity means that a significant portion of the air is occupied by water vapor. Water vapor is lighter than the nitrogen and oxygen that make up the majority of the atmosphere, further contributing to a decrease in density and therefore lowering the atmospheric pressure.

This phenomenon is often observed in tropical and subtropical climates where high temperatures and humidity are common. The resulting low pressure can lead to weather conditions such as thunderstorms and other severe weather patterns.

While high temperature affects pressure by reducing density, high humidity also plays a crucial role in creating a low-pressure system, making it the correct choice in this context. In contrast, the other options do not align with the dynamics influenced by warm, humid conditions.