Why in news?
Recently IMD has made an error in predicting the monsoon.
What are the functions of IMD?
- The India Meteorological Department (IMD), is an agency of the Ministry of Earth Sciences, responsible for meteorological observations, weather forecasting and seismology.
- It is headquartered in Pune with regional offices at Mumbai, Kolkata, Nagpur and Delhi.
- In April, the IMD had predicted “near normal” or 96% rains and then upgraded the figure to 98% a couple of months later.
- These percentages refer to the proportion of rains to 89 cm, a 50-year average of monsoon rains.
What is the recent prediction error made by IMD?
- The recent predictions made by IMD went wrong, at the end of this monsoon there were “below normal” rains (that is, less than 96% of the 50-year long period average).
- A single number 96 or 95, has the power to brand rainfall as “near” or “below” normal.
- A 98% forecast implies a range from 94% to 102% and so could span “below normal” to “above normal”.
- The IMD continues to persevere with the meaningless practice of assigning an overall number to the quantum of rain expected during the monsoon.
- This exercise of Monsoon prediction was initially conceived as a measure to warn the government about a draught or weak rains.
- But now this has become just an exercise of numbers secured with statistical error margins to rationalise a wrong forecast.
What are the impacts of faulty prediction?
- Faulty predictions of intra-seasonal variation or forecasting a change in global weather can affect agricultural outputs and normal lives of the people.
- The outcome of focussing on quantitative numbershas ripple effects from policymakers to stock markets.
- This leads to dilemma for policy makers for addressing the farmers who seek localised, actionable inputs on sowing or harvesting decisions.
- Performance assessment of monsoon on agriculture and economy will be delayed due to the faulty prediction.
Way forward
- India Meteorological Department is one of the six Regional Specialised Meteorological Centres of the World Meteorological Organization, faulty predictions will make its reliability dubious.
- The rain estimates needs to warn threatening weather and must be operationally useful rather than reduce rain to numerical jugglery.
- Thus IMD needs to take efforts to upgrade its supercomputers and sophisticated models to warn of weather changes at the district level.
Source: The Hindu
