English Hindi


Prelims Capsule


Indian Monsoon Season onset delayed says IMD

Indian Monsoon Season onset delayed says IMD


  • GS 1 || Geography || Indian Physical Geography || Monsoons

Why in the news?

Delay in monsoon has its own impact, monsoon is one of the most important economic factor especially in India

Monsoon in India:

Weather plays an important role in the socioeconomic life of a country. Monsoon is one of the most complex weather systems in the world which has become the life line of our country. In one way, the monsoon also defines the unity of the country by maintaining the same seasoning system from north to south and from east to west.

Monsoon forecast:

  • Forecasting monsoons is a difficult challenge on the Indian subcontinent, where monsoons are a major weather system that affects a big population.
  • Short and medium-range predictions, as well as seasonal predictions, are required for a variety of weather-sensitive activities such as farming, flood forecasting, water resource management, sports, and transportation.
  • Due to the intricate interconnections involved, forecasting the monsoon weather system and related rainfall is one of the most challenging topics in Numerical Weather Prediction (NWP).
  • These include topographic effects, synoptic scale system treatment, mesoscale convective systems, and the lack of excellent quality high resolution data across land and water.
  • This year, the India Meteorological Department (IMD) may adopt new monsoon models to better anticipate rainfall variations.
  • Dynamical Model:
    • The Monsoon Mission Coupled Forecast System is another name for it. It uses supercomputers to simulate the physics of the ocean and atmosphere theoretically.
    • This model is better at forecasting the status of the weather a week or two ahead of time, but meteorologists still don’t trust it to anticipate the monsoon.
  • Statistical Model:
    • Traditional statistical models relate correlations of physical characteristics with actual recorded rainfall in the past, such as sea surface temperatures, snowfall, landmass temperature, and so on.
    • For example, it takes into account global meteorological models that show El Nino, a warming of the central equatorial Pacific linked to the drying up of monsoon rain, as a remote possibility. This model is used by the IMD.
    • There is a 33% possibility of a regular monsoon in any given year, which is why there is high confidence that the monsoon in 2020 will be normal.
  • Proposed Models- The three models under consideration are:
    • 12 dynamical global circulation models whose outputs would be integrated into one.
    • In the tropics, a model that calculates rainfall depending on sea surface temperature.
    • Statistical models based on pre-monsoon climatic variables; all of them are ‘ensembles,’ meaning smaller models are merged to arrive at an average value.

Why is it difficult to forecast monsoon in India?

  • El Nino Southern Oscillation (ENSO): A climatic event linked to the warming of the eastern Pacific Ocean. Other variables, such as the Indian Ocean Dipole (IOD), which is the difference in Sea Surface Temperature between the western Indian Ocean in the Arabian Sea and the eastern Indian Ocean in the Bay of Bengal, moderate or increase El Nino’s influence. A positive IOD is caused by a warmer western pole, which can operate as a counter-cyclone to El Nino and result in normal rainfall. Equatorial Indian Ocean Oscillation (EQUINOO), Madden Julian Oscillation, and others are among the other contributors. Furthermore, they have complicated relationships with one another, thus complicating the situation.
  • Anthropogenic Emissions affect rain patterns: More variability in the monsoon is directly proportional to a warmer atmosphere.
  • Air Pollution: As aerosols such as black carbon interact with sunlight, they scatter or absorb light, which complicates rainfall unpredictability. Scattering prevents light from warming the earth’s surface, but absorption allows the particles to warm the air surrounding them, altering the atmosphere’s heating pattern and the warming of the land in relation to the ocean.
  • Forest Cover: Around a quarter of the precipitation in the broad basin of eastern India originates from the land surface in August and September, primarily through evapotranspiration in the forests. Deforestation on a large scale throughout the world has the potential to reduce the Indian Monsoon by 18%.
  • Other factors: For instance dust over in North Africa and the Arabian Peninsula absorbs sunlight, heats the air, and intensifies the wind, which carries moisture eastward and causes heavy rain in India. Similarly, climate change adds to the complication.
  • Factor responsible for monsoon prediction: The Monsoon winds (South west monsoon and the North east monsoon), Location of Himalayas, western and eastern Ghats, Altitude, Distance from sea, Latitudinal location, Upper Air Circulation,Tropical Cyclones & Western Disturbances, Southern Oscillations, El-Nino Effect, La-Nino Effect, Shifting Of ITCZ

Missions to forecast monsoons:

  • Monsoon Mission of India: This Ministry of Earth Sciences program, which began in 2012, has used novel methodologies (high resolution, super parameterizations, data assimilation, and so on) to increase prediction skill quantitatively for India Meteorological Department forecasting services (IMD).
    • The goal was to create a cutting-edge dynamical forecast system for monsoon rainfall on various time scales.
    • The Indian Institute of Tropical Meteorology (IITM) in Pune is in charge of the mission’s implementation and coordination.
    • The Climate Forecast System (CFS) of the United States has been chosen as the primary modeling system for the following purposes since it is one of the finest.
  • The IMD’s monsoon model, the Coupled Anticipate Model (CFS), which is part of the National Monsoon Mission (NMM), failed to forecast the excessive rainfall that occurred in August and September 2019.
  • National Monsoon Mission are:
  • Objective:-
  1. Create more accurate mathematical and simulation models
  2. Improve collaboration between research and operational entities..
  3. To increase the efficiency of organizations, infrastructure and skilled staff must be developed.
  • Steps taken:-
  1. New designs CFS are used to forecast short, medium, and long-term outcomes.
  2. Flood forecasting is available for many river basins.
  3. In Delhi, an air pollution monitoring and forecasting system has been established.
  • Achievements: –Several natural disasters struck India in 2013-14, including Phailin, Helen, Lehar, Mahasen, Madi, and others. The government was able to take timely actions because of improvements in data assimilation methods and climate models, which were well welcomed.


India’s monsoon has a long history of unpredictability and uncertainty. Given that agriculture employs about 70% of the population, even a minor shift in the Monsoon pattern would have a significant impact on the economy. More than 50% of cultivated area in India depends on Monsoon, hence an early warning system becomes necessary. Proper prediction of monsoon is very much necessary for proper cultivation and bigger infrastructure projects, tourism and many more.

Mains oriented question:

Write a note of India’s Monsoon Mission’s goals and accomplishments. (200 words)