Home >> Science & Nature >> Nature

How Does Barometric Pressure Change With the Weather?

Though the effects of weather systems may be highly visible, the forces that govern them are unseen. Wind, air pressure and heat energy continuously interchange, forming patterns and cycles that change and control the Earth's weather.

Barometric Pressure Definition
- Barometric pressure is the amount of pressure, or force, that air exerts over a given area ever the Earth's surface, as measured by a barometer.
Significance
- To maintain pressure equilibrium, air continuously flows upward or downward to correct pressure imbalances caused by weather patterns and natural temperature shifts. This air flow creates wind.
High Pressure Effects
- USAToday.com weather correspondent Jack Williams explains that if the air in a given location is heated, or if an opposing weather system blocks its flow, the barometric pressure will rise. In a high pressure system, air slowly moves downward. As the air descends, it warms, making it difficult for clouds to form. For this reason, high pressure systems are generally associated with good weather.
Low Pressure Effects
- If the air in a given space cools, its molecules move more slowly, and its pressure decreases, causing it to rise. The air cools as it rises, causing condensation droplets, which turn to rain and snow. Low pressure systems are most often associated with poor weather.

Nature