By Express News Service
Global warming and climate change has hit India hard with dire warnings about El Nino’s impact on the coming monsoon. The man in charge of forecasting the weather in India, Indian Meteorological Department (IMD) Director General, Dr Mrutyunjay Mohapatra speaks to Jitendra Choubey and discusses climate, infrastructural challenges before IMD and what has changed. Why has the IMD not forecasted heat and rising temperature on the line of the monsoon forecast?We forecast for the period which usually gets predominant weather conditions like monsoon (June to September), cold wave (December-January) and heat wave (March to May). 2000 persons died in 2015 and since then we have been issuing temperature forecasts .Our early forecast led to a considerable reduction in the number of deaths. In February, we usually do not get heat wave-like conditions, which was a rare event this year. In such a condition, we choose to do a monthly forecast.
What are the IMDs monsoons forecast? How will El Nino impact the monsoon?
Every month, we provide a forecast for El Nino and La Nina. Our summer forecast (March to May) suggests a neutral condition for El Nino.
However, many models show that if El Nino conditions develop, it would impact only the second half of the monsoon, i.e. lesser rain in the second half of the monsoon. But there is a rider. The accuracy of this forecast is lower as there is a spring barrier.
Why is Western Disturbance (WD) dynamics changing? It is getting lighter and feebler. Also, temperatures are rising by the day. Why is this happening?
Rainfall due to WD is decreasing while the numbers of WD are not decreasing. We are yet to ascertain the reason for feeble WD. An unusual rise in temperatures is the impact of a large global weather phenomenon. If you don’t have rainfall in WD, then the temperature will rise. This year in Eurasia, there was a 60% snowfall deficit which in turn caused a deficit in winter rainfall since November. Europe has a drought-like condition so the wind coming from the west was warmer, not colder which in turn caused deficit rainfall in North-West India. Dust is emerging as another challenge impacting weather.With rising global temperature, the dust trend is increasing. The best we can do is to monitor, record and predict the dust event. It is easier for us to predict in-situ dust phenomena. After data analysis, we can know whether the place is developing pressure gradient, internal heating, moisture condition, and intensity without moisture. All these conditions are behind any convective activities which trigger dust storms.
Do dust storms reduce the rainfall intensity?
Certainly! It is the reason behind the cooling effect after dust storms. But many other phenomena also contribute to reducing rainfall along with dust storms like aerosols and hygroscopic aerosols which can absorb moisture and hence increase selectivity.
Is there any trend related to rainfall reduction due to aerosols?
We noticed that frequency of the heavy rainfall is decreasing in the eastern parts of the country, especially the north-eastern parts, Bihar and Jharkhand. However, there is an increasing trend in the central part such as Gujarat, Odisha and northern peninsula. Heavy rainfall is decreasing in the Gangetic region due to higher concentrations of Aerosols like black carbon.
Why is our weather forecast not as precise as that of the US and EU?
It is a very general statement. We need to compare similar things instead of two different things. There are two types of weather events: tropical weather and extra tropical weather events. The Indian subcontinent is part of tropical weather, while north of the USA and the whole of Europe has extra-tropical weather.
If you want to compare the forecast accuracy then you should compare the forecast of the tropical region of the US with India. We also need more infrastructure and they are better positioned. The US has at least 200 radars while we only have 37 radars.
What exactly went wrong in 2022 about predicting the onset of the monsoon?
Nothing went wrong last year. We followed scientific facts instead of politics. We declared monsoon based on the conditions of monsoon onset. There is a well-defined monsoon criterion.
Why is IMD unable to forecast cloud bursting?
Global meteorology agencies do not even predict Cloudburst, forget about the IMD. It is such a small-scale phenomenon that even satellites cannot detect. The resolution of the Indian satellite is 4 km in infra-red range. Cloud burst is a single cloud that may be of one Km or less but radar has a resolution of 350 metres which can detect.
Social media is now swarming with weather ‘experts’. Your take?
I term them as ‘weather quack’. They act in a manner that they produce their data. However, they use our data only but don’t recognize us. IMD is the first weather bureau of any developing country to develop and maintain its own satellite system. How is IMD helping other countries?
As a regional leader, we provide observational data, satellite data, radar images, and the finished product that is forecast, like severe weather, including heavy rainfall, wind, cyclones, and dust storms. We provide cyclone related information to 13 countries including Thailand. Basically, countries affected by the Bay of Bengal and Arabian Sea.
Global warming and climate change has hit India hard with dire warnings about El Nino’s impact on the coming monsoon. The man in charge of forecasting the weather in India, Indian Meteorological Department (IMD) Director General, Dr Mrutyunjay Mohapatra speaks to Jitendra Choubey and discusses climate, infrastructural challenges before IMD and what has changed.
Why has the IMD not forecasted heat and rising temperature on the line of the monsoon forecast?
We forecast for the period which usually gets predominant weather conditions like monsoon (June to September), cold wave (December-January) and heat wave (March to May). 2000 persons died in 2015 and since then we have been issuing temperature forecasts .Our early forecast led to a considerable reduction in the number of deaths. In February, we usually do not get heat wave-like conditions, which was a rare event this year. In such a condition, we choose to do a monthly forecast.
What are the IMDs monsoons forecast? How will El Nino impact the monsoon?
Every month, we provide a forecast for El Nino and La Nina. Our summer forecast (March to May) suggests a neutral condition for El Nino. googletag.cmd.push(function() {googletag.display(‘div-gpt-ad-8052921-2’); });
However, many models show that if El Nino conditions develop, it would impact only the second half of the monsoon, i.e. lesser rain in the second half of the monsoon. But there is a rider. The accuracy of this forecast is lower as there is a spring barrier.
Why is Western Disturbance (WD) dynamics changing? It is getting lighter and feebler. Also, temperatures are rising by the day. Why is this happening?
Rainfall due to WD is decreasing while the numbers of WD are not decreasing. We are yet to ascertain the reason for feeble WD. An unusual rise in temperatures is the impact of a large global weather phenomenon. If you don’t have rainfall in WD, then the temperature will rise. This year in Eurasia, there was a 60% snowfall deficit which in turn caused a deficit in winter rainfall since November. Europe has a drought-like condition so the wind coming from the west was warmer, not colder which in turn caused deficit rainfall in North-West India.
Dust is emerging as another challenge impacting weather.
With rising global temperature, the dust trend is increasing. The best we can do is to monitor, record and predict the dust event. It is easier for us to predict in-situ dust phenomena. After data analysis, we can know whether the place is developing pressure gradient, internal heating, moisture condition, and intensity without moisture. All these conditions are behind any convective activities which trigger dust storms.
Do dust storms reduce the rainfall intensity?
Certainly! It is the reason behind the cooling effect after dust storms. But many other phenomena also contribute to reducing rainfall along with dust storms like aerosols and hygroscopic aerosols which can absorb moisture and hence increase selectivity.
Is there any trend related to rainfall reduction due to aerosols?
We noticed that frequency of the heavy rainfall is decreasing in the eastern parts of the country, especially the north-eastern parts, Bihar and Jharkhand. However, there is an increasing trend in the central part such as Gujarat, Odisha and northern peninsula. Heavy rainfall is decreasing in the Gangetic region due to higher concentrations of Aerosols like black carbon.
Why is our weather forecast not as precise as that of the US and EU?
It is a very general statement. We need to compare similar things instead of two different things. There are two types of weather events: tropical weather and extra tropical weather events. The Indian subcontinent is part of tropical weather, while north of the USA and the whole of Europe has extra-tropical weather.
If you want to compare the forecast accuracy then you should compare the forecast of the tropical region of the US with India. We also need more infrastructure and they are better positioned. The US has at least 200 radars while we only have 37 radars.
What exactly went wrong in 2022 about predicting the onset of the monsoon?
Nothing went wrong last year. We followed scientific facts instead of politics. We declared monsoon based on the conditions of monsoon onset. There is a well-defined monsoon criterion.
Why is IMD unable to forecast cloud bursting?
Global meteorology agencies do not even predict Cloudburst, forget about the IMD. It is such a small-scale phenomenon that even satellites cannot detect. The resolution of the Indian satellite is 4 km in infra-red range. Cloud burst is a single cloud that may be of one Km or less but radar has a resolution of 350 metres which can detect.
Social media is now swarming with weather ‘experts’. Your take?
I term them as ‘weather quack’. They act in a manner that they produce their data. However, they use our data only but don’t recognize us.
IMD is the first weather bureau of any developing country to develop and maintain its own satellite system. How is IMD helping other countries?
As a regional leader, we provide observational data, satellite data, radar images, and the finished product that is forecast, like severe weather, including heavy rainfall, wind, cyclones, and dust storms. We provide cyclone related information to 13 countries including Thailand. Basically, countries affected by the Bay of Bengal and Arabian Sea.
