The India Metereology Department (IMD) on Friday introduced two state-of-the-art global technology systems for accurate forecast of weather conditions down to the block level. With this system, the IMD would be able to precisely forecast how much rainfall will occur in any particular area.
Announcing the launch of the new system, Ministry of Environment & Forest (MoEF) Secretary M Rajeevan Nair said with this, India will have the best short-term forecasting systems in the world.
With the introduction of the high resolution Ensemble Prediction System (EPS), the MoEF hopes to improve the quality of forecasting, and also provide longer lead times — so that there is adequate preparation time — before an adverse weather scenario sets in.
“The new model was developed with the procurement of penta computers at a cost of Rs 450 crore. The IMD (New Delhi), Indian Institute of Tropical Metereology (Pune) and National Centre for Medium Range Forecasting (Noida) have worked together to develop this model,” Nair said.
The Indian model has a resolution of 12 sq km, a vast improvement on the previous model of forecasting, which had a resolution of 23 sq km. At present, only the European Centre for Medium-Range Weather Forecasts has a higher resolution at 9 sq km.
According to IMD Director General KJ Ramesh, the new system will help overcome the problem of uncertainties in the forecasts. It involves the generation of multiple forecasts using slightly varying initial conditions. The accuracy level would be very high in the new system.
The model has been on trial since September 2016 and has shown significant improvements in skill of daily weather forecasts. It was very helpful, especially in predicting the track and the intensity of the recent very severe cyclonic storm Vardah and the cold wave over the northern parts of India.
The EPS will enhance the weather information being provided by the current models by quantifying the uncertainties in the weather forecasts and generate probabilistic forecasts.
These new systems, according to the IMD, shall improve upon deterministic forecasts that are prone to high margins of error.
The EPS involves generation of multiple forecasts using slightly varying initial conditions.
“The frameworks of the new EPSs are among the best weather prediction systems in the world at present. Very few forecasting centres in the world use this high resolution for short-medium range probabilistic weather forecasts,” said officials of the IMD.
The IMD issues its forecast for the June-September monsoon season in April, which is based on the Ensemble Statistical Forecasting System that uses five predictors.
These predictors along with some equations are used by scientists to carry out a statistical analysis to finally come out with a forecast.
The problem is that this method uses data from the past 100 years to come up with a forecast when many of the relationships between global climate factors have changed.