When we talk about barometric pressure and weather, it might sound a bit too technical and scientific for a lot of us. But these concepts are quite simple and are understandable enough for the average person.
It also is very much essential for us to know and understand more about how barometric pressure and how it affects the weather. As outdoor enthusiasts, we need to know how volatile weather is depending on the atmospheric pressure.
What is barometric pressure?
Barometric pressure might sound a bit too technical, but it is just another term for air atmospheric pressure. That said, it’s the force that the air above the Earth’s surface exerts onto it. That might sound odd to some, but you have to understand that air still carries weight. And the weight that air in the Earth’s atmosphere carries exerts pressure onto the surface.
Like any other form of matter, the air molecules’ weight or pressure is determined by the air molecules above a particular area.
The more air molecules there is over a certain surface, the higher the barometric pressure will be. Similarly, the air’s low pressure is determined when there is a decrease in the air molecules over a particular surface. (Read How to Camp in the Winter)
Because air carries weight, it is easy to understand why low-altitude areas have higher barometric pressure readings. The molecules will be brought down closer to the Earth’s surface due to their weight.
That’s why sea-level areas have higher atmospheric pressures. In comparison, higher altitude areas have thinner air because air molecules there are not as abundant.
So, if you happen to be fond of mountain climbing, you would notice that it will be harder to breathe when the altitude increases. Meanwhile, it is relatively easy to breathe when you are by the beach because there tends to be a lot higher in the barometric pressure.
How does barometric pressure affect the weather?
At this point, you now have a better understanding of what barometric pressure is and how it affects the abundance of air depending on altitude. But you might be wondering, at this point, how atmospheric pressure can affect the weather.
Well, for starters, let’s talk more about how atmospheric pressure is related to temperature. If you listened to your basic science classes when you were younger, this would be simpler. Hot air tends to be lighter than cold air. That means that colder air tends to reside closer to the surface than hot air.
So, in that regard, hot areas tend to have lower air pressure than in cold regions. This is precisely because places with warm weather heat the air up, which will rise to the atmosphere. Meanwhile, comparatively cooler areas keep cold air closer to the surface and have higher barometric pressures. (Read Can You Tan When it’s Cloudy)
This eventually leads us to the discussion of what low-pressure and high-pressure systems are.
What are low-pressure systems?
You may have noticed that, when you monitor the weather, the term “low-pressure area” is often used. This refers to the barometric pressure above the surface of a certain area. Naturally, a low-pressure area means that the air pressure on that surface is lower than the area around it.
High winds and turbulent weather characterize low-pressure systems. This is because of how lighter hot air begins to rise to the atmosphere to cool down to form clouds. As a result, precipitation and tropical storms are quite common in low-pressure systems.
Moreover, places that are prone to low barometric pressure are usually the ones that do not experience extreme weather conditions. That is because the clouds above such areas often reflect the sun’s rays and act as some blanket.
That’s why, during the summers, low-pressure areas are not entirely hot. Meanwhile, at night, the blanket of clouds tends to keep the heat on the surface below to make sure the area doesn’t get too cold.
What are high-pressure systems?
On the other hand, when we are talking about high-pressure systems, they are the opposites of low-pressure areas. This happens when the atmosphere above a surface tends to be heavier. The air above the surface will come closer to the Earth as it cools down and becomes heavier.
As the air comes closer to the Earth, the atmosphere’s pressure begins to build up because of how they will fill up the void left above the surface. This phenomenon also tends to evaporate any water vapor left in the atmosphere.
That’s why high-pressures systems often have weather that is dry and calmer compared to low-pressure areas.
But because precipitation is less common in high-pressure systems, these areas are prone to extreme weather conditions. Clouds are less common, and the skies are clearer.
When that happens, daytime and summers tend to be quite warm while nighttime and winters are extremely cold. In short, the weather tends to be diurnal.
To make things understandable, we have a good summary of what we have discussed above.
Barometric pressure affects the weather due to how the temperature also affects atmospheric pressure.
Low-pressure regions allow warm air to rise into the atmosphere while high-pressure areas allow cold air to sink closer to the surface.
Because of this, low-pressure areas tend to have more precipitation and cloud formation as the rising air tends to cool.
That’s why these regions are prone to volatile and weather situations and why tropical storms are relatively common in low-pressure areas.
Meanwhile, high-pressure areas are not as prone to unpredictable weather because cloud formation tends to be less common.
But regions with high barometric pressures tend to be prone to extreme weather conditions. That’s why these places have really hot summers and extremely cold winters.
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