When the sun’s energy heats the Earth’s surface, water evaporates to produce water vapour, resulting in convectional rainfall. When the ground warms, the air above it warms, causing it to expand and rise. The air cools and condenses as it climbs. Clouds form high in the atmosphere as a result of this condensation process. Rainfall will occur if this procedure continues. This type of rainfall is common in tropical places and areas like South East England during warm sunny spells.

After discussing what is conventional precipitation, let’s discuss how it occurs!

How Does it Occur?

Stage 1

The sun warms the ground, which causes warm air to rise.

Stage 2

The air cools as it climbs, causing water vapour to condense and form clouds.

Stage 3

Large cumulonimbus clouds occur when the condensation point is reached.

Stage 4

There are heavy rainstorms. Thunder and lightning are common examples due to the electrical charge created by unstable conditions.

In locations where the ground is heated by the sun, such as the Tropics, convectional rainfall is common. This is why locations like the Amazon Rainforest get a lot of rain in the afternoons.

Convectional Storms

Convectional storms can be found all over the world. They’re most severe in sections in the tropics when there’s a water source and heat. They’re also widespread in warm mountain places like the European Alps in the summer. Strong rising air currents created a towering cloud in this spot.

When ice particles coalesce in a cloud, hailstones form.

Air currents drive the particles up and down in the cloud, forming fresh layers of ice around the nucleus. The hailstones eventually get too heavy to keep up with and tumble to the ground. 

Features of Convectional Precipitation

In addition to the definition of conventional precipitation, let’s discuss its features.

  •       As the air heats up, it becomes lighter and rises, creating convection currents.
  •       As the air rises, it expands, lowering the temperature, causing condensation and the formation of cumulus clouds.
  •       There is heavy rain with lightning and thunder, but it does not persist long.
  •       This type of rain usually occurs during the summer or the hottest period of the day.
  • This sort of rainfall is most common in the northern hemisphere, especially in the equatorial areas and interior parts of continents.
  • This type of rain is generally accompanied by hail and graupel.

Important Terms Related to Convectional Precipitation

Convection is responsible for this type of rainfall.

  • Intense surface heating and a plentiful supply of moisture are required for this sort of Precipitation.
  • As a result of the extreme heating of the surface, the surface air expands and rises, retaining moisture. After being adiabatically cooled, its temperature falls below the dew point, and clouds form.
  • Cumulonimbus clouds form at roughly 10 kilometres, resulting in intense rainfall. This rain is most common in the Equatorial zone, which receives direct sunlight nearly all year and thus receives more than 200 cm of yearly rainfall.
  • Thunder and lightning accompany this type of rain.

But what is the significance of the name “4 o’clock shower”? This type of rain occurs most frequently at about 4 p.m., and it is always accompanied by lightning and thunder.

Where does Convectional rainfall occur?

4 o’clock rain is another name for convectional rainfall. The high evaporation rate causes convectional rainfall. Then condensation occurs, and rain begins to fall. The temperature at the equator rises at midday when the sun is at its highest point. In the equatorial region, conventional Precipitation occurs. The surface of the Earth in these locations heats up because of the sun’s heat, and the air around it heats up as well. It spreads out and becomes lighter as it heats up, moving upwards. Condensation of water vapour occurs, resulting in rainfall.

What are the eight types of precipitation?

The following are the various types of precipitations:

  • Rain. Rain is most usually defined as drops larger than drizzle (0.02 inch / 0.5 mm or more).
  • Drizzle. Precipitation is fairly uniform and consists solely of fine, closely spaced drops.
  • Pellets of ice (Sleet)
  • Hail.
  • Minor Hail (Snow Pellets)
  • Snow.
  • Grains of Snow
  • Crystals of ice.

Conclusion

Rainfall produced by convection currents in the atmosphere is known as convectional Precipitation. The air temperature above the Earth’s surface rises when it is heated, as it is on hot summer days. An updraft is formed when heated air rises. As it rises through the atmosphere, the rising air gradually cools. Water vapour condenses in the cooler air to form clouds, which later precipitate as rain or hail. As rain falls, it cools the air around it.