Weather for Kids

Subject: Air Pressure

Did you know that we are constantly surrounded by tiny air particles that press down on us like a weight? The air particles are too tiny to see, but they take up space all around us. The weight associatied with these particles is called air pressure.

I'll try to give you an example of air pressure.

Imagine a balloon that is inflated with air. The balloon is released and begins to rise from the ground. As the altitude of the balloon increases, the air pressure pressing against the outside of the balloon decreases. The amount of air in the balloon stays the same and therefore so does the pressure that it exerts outward. As the balloon rises higher and higher, it becomes larger because the outside air pressure continues to decrease. When the balloon reaches a height where the air pressure inside is greater than the outside pressure, the balloon will burst or explode.

Air pressure can tell us a lot about weather. Can you name two different types of air pressure that relate to weather? One is called high pressure, which usually means sunny and calm weather for Montana. On the other hand, low pressure is known to bring cloudy and stormy weather. In general, the lower the air pressure outside the stronger the storm will be!

Air moves from a high pressure area toward a low pressure area. Meteorologists often use an instrument called a barometer to measure air pressure and the change in pressure, to track the movement of high and low pressure systems and the weather associated with them.