Virga: What is it and how it is formed

The virga is a Meteorological phenomenon which refers to the fall of precipitation, usually in the form of rain or snowfrom the clouds to the lower atmosphere, but what The earth’s surface does not reach. In other words, it is the observation of rain or snow that rushes from clouds but evaporates or sublima Before reaching the ground.

This phenomenon occurs when rain drops or snow crystals are formed in clouds at considerable altitude And during their descent, they find atmospheric conditions that favor evaporation or sublimation Before reaching the ground. This may be due to several factors, such as the presence of dry air in the lower layers of the atmosphere or the heating of the surrounding air that evaporates the drops before they reach the surface.

The virga is commonly observed in Arid regions or in climates where the moisture in the lower layers of the atmosphere is low. Although precipitation does not touch the ground, the virga can be indicative of the presence of vertical development clouds, such as storm clouds, which are capable of generating precipitation, but where conditions in the lower layer prevent it from reaching the ground effectively.

From the meteorological point of view, the virga can be an important component in the understanding of climatic patterns and atmospheric dynamics. In addition, its observation can have impacts on time prediction, since it indicates the presence of clouds and the possibility of adverse weather conditions in the region.

The formation of the Virga implies several atmospheric processes and specific conditions that affect rain drops or snow crystals as they descend from the clouds. These are the atmospheric conditions that should be given to form the virga:

• Cloud formation: The first phase begins with the formation of clouds in the atmosphere. The clouds are generated when the wet air rises, cools and the water vapor contained in the air is condensed in small water particles or ice crystals. These particles are grouped to form clouds. You can learn more about how the clouds are formed here.
• Vertical development of clouds: In order for the virga to occur, it is common for clouds to be of vertical development, such as storm clouds or cumulonimbus. These clouds can extend to great heights in the atmosphere.
• Growth of rain drops or snow crystals: Within these clouds, rain drops or snow crystals continue to grow as they collide and merge with other particles. In the case of rain, drops can grow by coalescence, where they merge with other smaller drops.
• Descent from the cloud: Rain drops or snow crystals, now larger, begin to descend from the cloud due to gravity. As they descend, they are subject to ascending and descending air currents inside the cloud.
• Adverse atmospheric conditions: The virga is formed when atmospheric conditions in the lower layers are unfavorable for precipitation to reach the surface. This may be due to the presence of dry air in those layers or a heating of the surrounding air.
• Evaporation or sublimation: As rain drops or snow crystals descend through lower air layers, they find conditions that favor evaporation (in the case of rain drops) or sublimation (in the case of snow crystals). These processes turn water into steam before the ground reaches.

Although not in the same way as on earth, we can find the virga phenomenon in the Planet Venus. Venus has one dense atmosphere mainly composed of carbon dioxide, with traces of sulfuric acid clouds, and its surface is dominated by high temperatures and overwhelming atmospheric pressure.

In Venus, the same conditions that favor the formation of Virga are not given as those found on earth. However, Venus has such a dense and opaque atmosphere that Rain drops do not reach significant altitudes before evaporating. In the atmosphere of Venus they occur Sulfuric acid rainsthat fall evaporating before reaching the ground, due to the intense heat on its surface.

There are several phenomena related to precipitation that share similarities with the Virga, since they involve the formation of rain drops or snow crystals that do not touch the ground in their original state. Some of these phenomena are:

• Serpentines or Virga tails: This phenomenon is similar to the Virga, but instead of precipitation evaporates before reaching the ground, it moves horizontally with the winds at lower altitudes. In this case, rain drops or snow crystals are formed in the clouds and fall, but air currents transport them to lower altitudes before reaching the ground. This effect can create notable visual appearances, such as “queues” of precipitation that extend from the clouds.
• Virga fog: Although fog is not a form of precipitation, in some situations, a phenomenon called “Virga fog” can be observed. This occurs when the virga meets a more humid layer of air and close to the ground. Although the precipitation does not reach the ground in its original state, the additional humidity in the atmosphere near the ground can condense to form fog.
• Evaporating precipitation: Similar to the virga, evaporating precipitation occurs when rain drops or snow crystals are formed in the clouds but evaporate before reaching the ground due to dry conditions in the lower layers of the atmosphere. This phenomenon is common in areas with dry air, where evaporation occurs rapidly during the descent of precipitation.

Now that you have discovered what the Virga is, we recommend you discover another phenomenon that seems strange, the horizontal rain: what is and where.

If you want to read more articles similar to Virga: What is it and how it is formedwe recommend that you enter our category of meteorological phenomena.