Light or heavy rain... Why does rainfall differ from time to time?

Arabia Weather - On some days, the rain falls softly and gently, touching the ground gently, nourishing and refreshing it, but on other days, the rain falls heavily, and according to statements by meteorologists, these strong rainstorms can make standing outside feel as if you are trapped under a heavy, wet towel. Not only that, but these storms can flood lands, causing massive destruction.

As an explanation for this phenomenon, Jeffrey B. explains: Halvorson, a professor of geography and ecosystems and associate dean of the graduate school at the University of Maryland, Baltimore County, explains the reasons for this disparity in an article published on the website The Conversation.

Why does rainfall vary from time to time?

Answer: Rainfall is caused by a complex interaction between moisture in the air, which usually appears in the form of clouds, and air currents moving in different directions. When moist air rises through the clouds, it cools, causing the water it contains to turn into raindrops. Small.

This phenomenon can be likened to what happens when you see your breath on a cold night, where the change in temperature causes the formation of water droplets in your breath. These small droplets are very light, and float thanks to the push of rising air, but as they rise, their size and weight increase, until they become heavy. So much, that it falls to the ground as rain.

Cold air, fluffy winter clouds and summer thunderstorms

Cold air usually carries less moisture than warm air, so winter clouds do not contain a lot of water . For this reason, these clouds are thin and composed of layers. They are not characterized by large swelling or long elevation and are filled with water. Because of the difficulty of raising cold air quickly, the clouds remain This winter season contains simple upward air currents.

If these slow currents flow over thin clouds that contain limited moisture, small raindrops are formed that are easily pulled down as a result of gravity, which is the opposite of the air current. When the clouds are weak and the wind moves slowly, light and calm rain results.

As for severe storms, they occur when there is a high percentage of humidity in the air, as the wind moves very quickly upward, as is the case in summer thunderstorms, and the warm and humid air rises at a tremendous speed, and the speed of movement may reach 48 to 64 kilometers per hour. Hourly, the air retains large amounts of moisture, up to five times more than that found in winter clouds.

This rise in humidity and the speed of air movement leads to the formation of long, dense clouds filled with moisture. When the air moves up through these clouds, water droplets form quickly, but because of the speed of the wind, the droplets may swell before gravity pulls them down.

When the force of the wind is no longer able to support the weight of the water droplets, the wind stream collapses, and all the raindrops fall into the cloud immediately, forming summer thunderstorms.

Sudden heavy rains are capable of falling 2 or even 3 inches (2.54 to 7.62 centimeters) in less than an hour, and these heavy rains can cause instant flooding, flowing onto roads, obscuring people wherever they are.

Fortunately, violent thunderstorms are generally short-lived, as the clouds disappear and the sky appears a pleasant blue color once the rain falls and the updrafts break.

Of course, winter can also cause powerful storms, especially over warmer oceans. When large amounts of rain fall, the same principles work:

• Too much moisture in the air
• And fast upward wind currents
• And long clouds

Knowing that no two storms are the same, sometimes the rain can fall so hard that it makes you feel like you are in the shower, while at other times there is just a gentle, gentle drizzle. Now, whether you are drenched in the rain or enjoying singing under it, you You will know the reason behind this discrepancy.

Also know:

On the first days of rain... 5 useful tips

How do you ride your motorcycle in the rain?

Sources:

aljazeera