IMD’s First-Stage Forecast for 2021

Why in news?

India Meteorological Department (IMD) released its first-stage forecast for the south-west monsoon for 2021.

How is 2021 likely to be?

• IMD's forecast suggests that monsoon in 2021 may not be as bountiful as in last year; it does however offers some hope.
• The forecast for the south-west monsoon indicates that the quantum of rainfall is likely to be at 98% of the long period average.
• It estimates a 61% probability of the country ending up with normal or excess rains.
  • It actually expected rainfall at 100% of the long period average with a 70% probability of normal to excess rains.

What is the need for caution though?

• A normal monsoon this year is obviously welcome as it could help agriculture GDP expand for the third consecutive year.
• Nevertheless, these preliminary forecasts cannot be taken for the good prospects for the farm economy.
• IMD’s first-stage long-range forecast is generally too early to capture the evolving impact of phenomena such as the ENSO and IOD.
  • ENSO - El Nino Southern Oscillation; IOD - Indian Ocean Dipole
• Notably, these have proved to be critical swing factors influencing south-west monsoon performances in the past.
• IMD expects the current year’s monsoon to be less generous than last year’s.
• While neutral conditions now prevail on both the ENSO and IOD, IMD is watchful on negative IOD conditions developing as the season progresses.
• Last year, it was an unfolding La Nina that led to rainfall eventually exceeding IMD’s estimates at 109% of the long-term average.
• Also, IMD has been improving its record at foreseeing normal and excess monsoon years.
• But, it has tended to over-estimate rainfall in drought years such as 2002, 2009, 2014 and 2015.
• On this score, its second-stage forecast in June, factoring in evolving weather conditions, is somewhat more reliable.
• There is also the fact that three consecutive normal monsoon years have been quite rare for India.

What is the way ahead?

• The monsoon is no longer adhering to its historical patterns.
• So, there has been increasing demand from farmers and policymakers for more granular forecasts on its spatial and temporal spread.
• On this score, it is good to see IMD introduce a new dynamical Multi-Modal Ensemble forecasting system this year.
• This will not just provide month-wise break-ups but also focus on rain-fed agricultural regions.
• While the IMD is improving its forecasting abilities, the Centre and State governments are yet to properly use this valuable data.
• They should use the data to -
  1. appropriately guide cropping patterns
  2. correctly estimate the demand-supply equation for essential crops
  3. set trade policies
  4. achieve a better state of disaster-preparedness against floods and famines that devastate individual districts every year

Source: Business Line