India’s weather office, the India Meteorological Department, is one of the country’s oldest scientific organisations and marked 150 years of its existence on Tuesday. While most are celebrating its successes, many still make fun of its predictions – a common joke goes that if the IMD predicts rainfall, please leave your umbrella at home. This is unfair to an organisation that helps forecast weather for a country as geographically diverse and as big as India.
Most people compare the forecasts issued for cities like New York, Washington DC, London or Paris and suggest that weather offices there are able to give accurate forecasts, while the IMD fumbles.
The western cities we compare the forecasts with all fall in the temperate zone, where the weather is fairly stable and predictable. In comparison, India is a tropical country and the prevailing atmospheric conditions are best described as ‘chaotic’. Scientifically, ‘chaos’ is best defined as a ‘deterministic system that’s difficult to predict because it is sensitive to small changes in initial conditions’.
In tropical conditions, making forecasts is very difficult and that has to do with the inherent lack of understanding of the science of ‘chaos’. Given these conditions, the fact that the IMD makes accountable forecasts is very creditable, and that they are improving is even better. Today, IMD’s three-day forecasts and nowcasts, all called short-term forecasts, are becoming very accurate. It is the medium-term and long-range forecasts where improvements will help.
At the 150th Foundation Day celebrations of the IMD, Prime Minister Narendra Modi lauded this short-term forecast and said he was a big beneficiary, highlighting that the inauguration of the Z-Morh or Sonmarg Tunnel in Jammu and Kashmir’s Ganderbal was scheduled for Monday after consulting the local weather office and that he was blessed with sunshine as predicted.
Cyclone Prediction
One area where the IMD has done incredibly well is in forecasting and tracking cyclones. Today, thanks to the use of satellite data and Doppler radars, the tracking of cyclones can be done with almost pinpoint precision. Before Indian weather satellites became operational, cyclones like the one which hit the Bay of Bengal in 1970 killed 300,000 people. Today, cyclones are tracked days in advance and the number of deaths has dropped to double digits or even none.
Speaking at the IMD event on Tuesday, PM Modi highlighted that the “integration of science and preparedness has also reduced economic losses worth billions of rupees, creating resilience in the economy and boosting investor confidence”.
Forecasting cyclones is indeed a huge achievement and some of the credit should go to India’s ‘cyclone forecasting hero’, Dr Mrutyunjay Mohapatra, the current head of the IMD, who is a specialist in the area.
Monsoon And Droughts
One place where the IMD needs to improve is long-range accurate forecasting of the Monsoon. This is critical for India as much of the rainfall in the country occurs in the June-to-September period, during the southwest Monsoon season. Forecasting the Monsoon is tough because the science behind doing so is still not well understood.
The country invested almost Rs 300 crore in the Monsoon Mission and upgraded supercomputers, but precision in this area eludes India’s weather office. The IMD gets criticised for this lack of precision, but the basics of this phenomenon, which depends on ocean-atmosphere interactions, elude global scientists too. On top of this, climate change is playing havoc with existing models.
Predicting a normal monsoon is the easiest as, statistically, doing so is better than predicting heads or tails on a flip of a coin. The greatest need is to be able to predict a drought early in the season and this requires deeper knowledge. Even now, despite massive computers and big data, it is the human skill of the weatherman which plays a big role.
Hopefully, the Rs 2,000-crore Mission Mausam inaugurated on Tuesday by PM Modi will help in deciphering the many unsolved mysteries of the Monsoon. Maybe the time has come to call a moratorium on long-range forecasting of the monsoon at least till such time as our scientists can better understand the underlying physics, chemistry and dynamics of what drives and sustains it.
Weather plays a critical role in the everyday lives of citizens and, today, the need is to be ‘weather ready and climate-smart’. Or, as India’s science minister Dr Jitendra Singh aptly put it, ‘Today, it is not what the weather will be tomorrow but what weather will do tomorrow’.
