August 13, 2020 – UPSC Current Affairs: Key Prelims News Topics

Heavy rainfall have hit the Telangana and Andhra Pradesh region. At least 30 people have lost their lives across Telangana out of which 19 deaths occurred in Hyderabad alone. The extremely heavy rainfall have caused a deluge in the region and has caused flooding in the region. The heavy and incessant rains occurred due to depression in the Bay of Bengal. Such type of rain are called as the Torrential Rain.

Torrential Rain

Heavy downpour of rain are called as Torrential rain. According to the National Weather Service (NWS), torrential rain are the rain that accumulates at the rate of three-tenths of an inch or more per hour. Though, the classification of the rain is not standardized in the world. But, generally Rain is classified as heavy when falling rate of rain is greater than or equal to 7.6mm of water per hour.

Why Torrential Rain occur?

  • The primary cause of torrential rain is moisture, that moves along the weather fronts. The moisture content is high in following cases:
  1. In case of weather conditions such as formation of cold fronts, tropical storms, hurricanes, andmonsoons.
  2. Rainy weather patterns such asEl Ninoand the Pacific coast’s Pineapple Express also increases the rainfall.
  3. Global warming is also linked with the phenomenon of increasing the moisture content in the air.
  • The convective clouds also causes precipitation. It occurs when enough moisture rises up due to an upward motion.
  • The cumulonimbus clouds causes the narrow torrential rain bands.

How Torrential Rains are formed?

Firstly, the air saturates with the water vapour and clouds are formed. The clouds then get suspended in the air and are visible from the Earth’s surface. In the next step, air cools down to dew point through the radiational cooling, evaporative cooling, conductive cooling and adiabatic cooling. These cool air rises up through convection or physical barriers such as a hill. Heavy condensation forces the water vapour to form the dark nimbus clouds that results into the Torrential Rainfall.