The water level in the Yamuna River rose to alarming levels, leading to severe flooding on major roads within Delhi in the last few days. The combination of heavy rains, flashfloods in north India and record-breaking global temperatures underscores the interconnectedness of climate change impacts. In the light of the extreme weather events, Indian Meteorological Department (IMD) director general Dr Mrutyunjay Mohapatra speaks to Jaison Wilson about the changing weather scenario in the city as well as the country.
Excepts:
What could be the reason behind record rains in Delhi?
There was an interaction between a western disturbance and the southwest monsoon that led to the extremely heavy rainfall situation being witnessed across states in north India including Delhi, Punjab, Jammu and Kashmir, Himachal Pradesh and Uttarakhand. The frequency of such events over the tropical region across the globe shows an increasing trend owing to the changing global climate scenario. India also, during the monsoon season, being a tropical country, is showing such a rising trend. Most weather stations in India are showing this trend.
How will the situation evolve in the next few days?
In this spell, because of the interaction scenario, as I said earlier, whatever the heavy rains occured, that’s over. Now it is ocurring over Uttarakhand and West UP. This activity will shift towards Bihar and northeastern states and then to the south, that is, towards central India starting with Odisha to Gujarat and rainfall will also increase.
What about the floods during the monsoon, as it suddenly happened two years back in Kerala?
Nothing happens suddenly. If you can capture it, if you can predict it, it is not sudden. The Kerala flood situation was well predicted. And now also the event which is occurring is being predicted. That kind of set up has come in the country. The prediction is possible at least three days in advance about heavy rains etc. We are providing colour coded warning, red colour warning orange colour warning, which prompt us to get into action. The country has come a long way. Also each state has improved their process in this regard. If you compare the current events with 2013 Kedarnath, when around 4000 people died, now it’s not the case.
How accurate are IMD predictions? How do they compare to developed countries?
You cannot compare with weather forecast in London with Delhi or other parts of India. It is not because of the developed and developing types of countries. It’s because of the nature of weather. For instance, 24 hour before heavy rainfall in Delhi, 78 per cent times, it will be correct. The weather system which affects UK, or northern parts of the United States are like “obedient children” rather than being “mischeivous”; they ‘go in a line’ to the school. It is easy to predict. Our country is tropical. In a tropical country, heating is the major source of all types of weather. So, here a thunderstorm occurs within after half an hour so, it disappears again sky becomes blue in color. So, my point is that it is the trigger for the weather system in tropical country is convective time. Whereas, in extra tropical countries like Western countries, there it is non-convective type. London doesn’t experiencing tropical cyclone. India experiences tropical cyclones. If you compare southern part of US like Florida, then you will come to know how much they are accurate and how much we are accurate.
You can also compare it in another way. Just see the number of deaths due to the cyclones in India and number of deaths due to cyclones in USA. So, by the way also as a layman you can find out where we stand nowadays you will see that number of deaths in India is less number of deaths are more in USA.
In cyclone forecasts, we have pinpointed forecast accuracy, almost zero error. You can see there is no casualty in ‘Biparjoy’ occurrence. In heatwave and coldwave, we have 92 per cent accuracy, I’m talking about the 24 hour in advance. With regard to thunderstorm, it’s 86% accuracy.
Heavy rainfall and thunderstorms are very small scale events. Their accuracy is 75 per cent to 85 per cent.
