Many people watch pressure indicators. Someone has an increased sensitivity to weather conditions and is forced to control the situation around to make a forecast regarding the state of their health and overall well-being.
In addition, fishermen observe the pressure to determine the time of the bite. And also this atmospheric indicator allows you to make a forecast regarding the weather in the near future, because many people know that it can be cloudy with a decrease in atmospheric pressure. Curious people have a logical question: why do circumstances turn out that way? Considering these processes from the point of view of the laws of physics, one can understand the regularity of what is happening and answer all questions.
Processes that occur in the atmosphere when pressure drops
Pressure always drops within a specific area, rather than universally. In an area with a decrease, a specific feature of air circulation is observed - molecules rush there, and then rise up, losing temperature. When cooling, the air may contain less moisture - this is its feature.
A hot atmosphere can be quite humid, and a cold one tends to free itself from excess water, which has nothing to do but condense in the form of clouds. That is, in areas with low pressure, air rises from the surface of the planet up, simultaneously getting rid of moisture, which forms clouds that move in the sky.But if we talk about high blood pressure, then the picture is completely different.
So, there is a lot of cold air, which is located at a considerable height. The masses decrease, mix with warm air and spread over the surface of the earth, forming along the way clear weather. There are no clouds, since there is nothing to condense - the air from a great height, where it is always cold and the molecules cool, not being able to raise a lot of moisture along the way, remains dry. There are no conditions for the formation of clouds, because the weather in this case remains sunny.
Atmospheric pressure and air circulation
Increased atmospheric pressure creates conditions when air humidity only decreases. When falling into the lower layers of molecules, which in the process can be heated, even existing clouds dissolve. After all, the air begins to absorb moisture again, taking it from the finished clouds. If we are talking about an anticyclone of this kind, weather forecasters can give an unambiguous forecast for clear weather, even if there are clouds in the sky. They will disappear, moreover rather quickly - if the forecast was given in the morning, they will be gone by lunchtime, people will be able to enjoy a clear sky, a sunny day.
But if we are talking about the cyclone as a high-pressure zone, the opposite situation is forming here, which allows us to predict cloudiness in the coming hours, even if the sky still remains clear. The ascending streams dry the air masses, and all their moisture condenses in the form of clouds, since it cannot disappear without a trace.
If the process is intense, then the clouds will form quickly, it may soon rain, all the condensed moisture will fall to the ground. But it also happens that the process lasts for hours, days. Rain may not be, or it may be protracted, shallow. Different situations happen, it all depends on the intensity of the processes. And their speed is affected by temperature and many other indicators.
Thus, pressure largely shapes the weather. It can be dry and clear at high rates, when air without moisture can dry even those clouds that already exist in the atmosphere. And it can also become rainy at low pressure, when clouds can form even with a clear sky, in just a few hours.
The circulation of molecules and the characteristics of the flows at different pressure indicators form the weather, making it rainy or clear. Sometimes the forecast is relevant only for hours, but in other cases it clearly demonstrates the state of the environment for the days ahead. Forecasters make forecasts, focusing on these and other indicators - the result is quite accurate.
