PORTLAND, Ore. (KOIN) – Today we are learning about air pressure, wind and weather conditions!
First, you can feel it when you’re outside and you can hear it when you’re inside. I guess that could be used as a riddle, but honestly, it’s not much of one. We all know what the wind sounds like creaking the house or the crinkling sound of the trees blowing. On a real windy day, the wind can even offer a hand on your movement. Running with the wind is much easier than running into the wind. Have you ever thought about how or what wind actually is? We will do our best to learn about pressure and wind in this Weather Kids lesson.
The wind is the air that is in motion. It sounds simple, but there is more to it (physics). We will try to keep this straightforward and we won’t be diving into some of the more in-depth concepts just yet. Now in this lesson, we will mostly be referring to horizontal wind. For example, you may hear a meteorologist say something like, “the wind is coming from the east out of the Gorge this afternoon.” That would be an example of horizontal wind.
Now a reason that air moves is because of the differences in atmospheric pressure. That change in air pressure is what is referred to as the pressure gradient. This is where we may refer to high or low pressure. Take a look at the airflow image above, this will help show the general concept of air around an area of high or low pressure. The air above high pressure is more dense than that of low pressure of the same temperature. Winds around an area of high pressure move in a clockwise fashion, where the wind around low pressure in the northern hemisphere will move counterclockwise. This is what we refer to as anticyclonic flow and cyclonic flow.
“Rising air cools and eventually will lead to condensation. This forms clouds and precipitation. Sinking air warms causing evaporation. Which means fewer clouds and fair weather.“
Air will flow from high pressure to areas of low pressure. Air pressure is one of the first concepts that was studied and used to help determine incoming weather. High pressure generally means sunnier and dry conditions. Where low pressure will reflect weather that is cloudy and possibly wet. That isn’t always the circumstance, but the reasoning behind this is because rising air cools and eventually leads to condensation. This forms clouds and precipitation. Sinking air warms causing evaporation. Which means fewer clouds and fair weather.