Convective rains

convective rains formac

As we know, there are numerous types of rain according to its origin and its characteristics. Today we are going to talk about convective rains. They are also known by the name of convection rain. They are precipitations that are produced by a decrease in atmospheric pressure at the local level. They are created as if it were clouds in a vertical form and the precipitations that it leaves are usually abundant.

In this article we are going to tell you everything you need to know about convective rains and how it originates.

Precipitation and formation

Storm clouds

The first thing that is important to know is how it occurs in precipitation. When the air on the surface heats up, it rises in altitude. The troposphere its temperature decreases with altitude, that is, the higher we go, the colder it is, so when the air mass rises, it runs into the colder air and becomes saturated. When saturated, it condenses into small droplets of water or ice crystals (depending on the temperature at which the surrounding air is) and surrounds small particles with a diameter less than two microns called hygroscopic condensation nuclei.

When the water drops cling to the condensation nuclei and the air masses on the surface do not stop rising, a cloud of vertical development is formed, since the amount of air that is saturating and condensing is such that ends up increasing in height. This type of clouds that are formed by atmospheric instability se le Llama cumulus humilis that, as they develop vertically and reach a considerable thickness (enough to allow hardly any solar radiation to pass through), is called  cumulonimbus.

For the vapor existing in an air mass that reaches saturation to condense into droplets, two conditions must be met: the first is that the air mass has cooled down enoughThe second is that there are hygroscopic condensation nuclei in the air on which water droplets can form.

Once the clouds have formed, what is it that causes them to give rise to rain, hail, or snow, that is, to some type of precipitation? The tiny droplets that make up the cloud and that are suspended within it thanks to the existence of updrafts, will begin to grow at the expense of other droplets that they find in their fall. Two forces act fundamentally on each droplet: due to drag that the rising air current exerts on it, and the weight of the droplet itself.

When the droplets are large enough to overcome the drag force, they will rush to the ground. The longer the water droplets spend in the cloud, the larger they become, as they add to other droplets and other condensation nuclei. In addition, they also depend on the time the droplets spend ascending and descending in the cloud and the greater the total amount of water that the cloud has.

Convective rains

convective rains

Convective rains are generated both by the rise of warm air and humid air. The earth is warming in some regions more than others. It all depends on the earth's surface and the incidence of solar radiation. The same happens with the type of vegetation that makes up each place. These characteristics make that the heat is transferred to the air that are the highest parts and on the form of a bubble. As the altitude rises, the temperature changes and defends until it becomes a bubble of cold air. In the case in which the air is loaded with humidity, a cloud is formed and that is when the condensation process occurs and then the precipitation falls.

The natural phenomenon of convective rains It can also be formed by a kind of mist. This allows the direct elevation of humid air that is related to the convection process and is characteristic of both hot and humid regions. It is not surprising that this phenomenon is more frequent during the summer seasons and in regions that have a predominant temperate climate. They usually occur in storms and come along with lightning and thunder.

It occurs in territories with flat characteristics or that have small imperfections in the topography. These places have the presence of humid and warm air that generates the formation of clouds of the Cumulonimbus type.

Origin of convective rains

cloud formation

These rains originate when an air mass that is at a higher temperature meets a water tributary such as a river. It causes this meeting, whose temperatures are different, to form a cloud that rapidly saturates the water vapor and produces heavy torrential rains.

When solar radiation hits the earth's surface intensely, the earth warms. When the water vapor rises it becomes saturated and comes into contact with the highest part of the atmosphere. As the air rises, it achieves lower temperatures and becomes condensed since they meet the dew point. This means that the temperature of the water vapor equals the condensation temperature.

For convective rains to occur it is necessary that the clouds have previously formed after the water vapor saturation process. This causes precipitation to be made up of large drops of water.

Key features

Let's see what are the main characteristics of convective rains:

  • Rainfall are generated by currents that rise thanks to humid air. This air rises and moves thanks to the well-known convection cells.
  • The air rises unexpectedly due to the little consistency that the air has around it, creating air pockets similar to a balloon.
  • As the air cools it reaches temperatures close to the dew point.
  • When the condensation of the air begins, the cloud begins to form and cause rains in the region where it has formed.
  • Convective rains They are typical of tropical regions where there is humid and warm air. It is usually accompanied by lightning and lightning and causes electrical storms.
  • They are rains that can also generate hail.

I hope that with this information you can learn more about convective rains and their characteristics.

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