Lok Sabha Question No. 4068 (UNSTARRED), answered on 2021-03-19
Subject: Mechanism for Prediction of Rainfall
Ministry: EARTH SCIENCES
Asked by: Rajiv Pratap Rudy

## GOVERNMENT OF INDIA

## MINISTRY OF EARTH SCIENCES LOK SABHA

## UNSTARRED QUESTION NO.4068

## TO BE ANSWERED ON FRIDAY, MARCH 19, 2021

## MECHANISM FOR PREDICTION OF RAINFALL

## 4068.   SHRI RAJIV PRATAP RUDY :

## Will the Minister of EARTH SCIENCES be pleased to state:

- (a) the details of the current mechanism being followed to predict the rainfall;
- (b) whether the Ministry is considering to take any steps to devise an intelligent prediction system  with  modern  analytic  tools  by  using  local  weather  information  for  rainfall prediction;
- (c) if so, the details thereof and if not, the reasons therefor;
- (d) the details of current flood warning system being used in country; and
- (e) whether the Government is taking any steps to improve the system and if so, the details thereof and if not, the reasons therefor?

## ANSWER

## MINISTER FOR MINISTRY OF SCIENCE AND TECHNOLOGY AND MINISTRY OF EARTH SCIENCES (DR. HARSH VARDHAN)

- (a) Rainfall  prediction  is  given  in  different  time  scales,  i.e.  seasonal  forecast  (for  the  whole season), extended range forecast (up to four weeks), short-medium range forecast (up to 7 days) and nowcasts (up to 3 hrs). These forecasts are generated using state of the art  weather  prediction  models  based  on  mathematical  equations  and  physics  of atmosphere and oceans.

An improved suite of prediction models has already been implemented operationally at India Meteorological Department (IMD) for enhanced short range weather forecasting through assimilation of all available Indian and global satellite data in real time.

Since December 2016, IMD is using the Global Forecast System (GFS) and Unified model  run  at  National  Centre  for  Medium  Range  Weather  Forecast  (NCMRWF) operationally  every  day  to  generate  deterministic  forecasts  at  12  km  horizontal resolution  in the short to medium range (up to 7 days). The GFS assimilates global conventional atmospheric data as well as the data from satellites and weather radars. There also exists a high resolution meso-scale model with 3 km resolution to provide location specific forecast.

In  addition,  a  high  resolution  (12  km  grid  scale)  state  of  the  art  Global  Ensemble Prediction System (GEPS) namely Global Ensemble Forecasting System (GEFS) and Unified model Ensemble Prediction System (UMEPS) was commissioned on 01 June 2018 for generating operational probabilistic weather forecasts for 10 days. The GEPS has  enhanced  the  weather  information  being  provided  by  the  current  models  by quantifying the uncertainties in the weather forecasts.

Under  the  National  Monsoon  Mission,  MoES  has  implemented  two  state-of-the-art dynamical prediction systems for short range to medium, extended range and seasonal forecasts.  All  these  initiatives  have  helped  to  improve  the  skill  of  monsoon  rainfall forecasts over the country. Since 2017, IMD is using the Monsoon Mission dynamical model to prepare operational seasonal forecast of monsoon rainfall over India.

- (b)-(c) The above mentioned forecast systems will be improved further for better accuracy with the enhancement in observational systems and advancement in numerical modeling and efforts  are on  for this  purpose.  The  Ministry  of  Earth  Sciences  (MoES)  has  invited proposals from research community for development of artificial intelligence (AI) and machine learning (ML) based tools & techniques for prediction of weather. Scientists at MOES are also involved in developing products based on AI and ML methods.
- (a) IMD has a shared mandate with Central Water Commission (CWC) for flood forecasting. River basin floods  are  dealt  by  the  CWC.  Flood  Meteorological  Offices  (FMOs)  operated  by  IMD  provide meteorological support to the CWC for issuing flood warnings in respect  of  the  43 rivers  of  India covering 153 river basins. CWC issues flood forecasts for about 6 hrs. to 30 hrs. in advance for 176 stations using Quantitative Precipitation Forecast (QPF) received from FMOs of IMD and insitu hydro-meteorological data.

In  order  to  meet  specific  requirements  of  flood  forecasting,  which  is  provided  by Central  Water  Commission  (CWC),  IMD  operates  Flood  Meteorological  Offices (FMOs)  at  thirteen locations  viz.,  Agra,  Ahmedabad,  Asansol,  Bhubaneshwar, Guwahati, Hyderabad, Jalpaiguri, Lucknow, New Delhi, Patna, Srinagar, Bengaluru and Chennai. Apart from this, IMD also supports Damodar Valley Corporation (DVC) by providing Quantitative Precipitation Forecast (QPF) for Damodar river basin areas for their flood forecasting activities.

CWC is working in close association with IMD and State Governments for timely flood forecast whenever the river water level rises above warning level. In order to cater to the services of hydro-meteorological events occurring in short duration of time, IMD has implemented a Flash Flood Guidance System (FFGS) with the technical help from World Meteorological Organization (WMO).

- (e) The weather forecasting and early warning systems in the country are comparable to most of the developed countries in the world. Efforts are continuously made to enhance the observational network and the level of efficiency of the forecasting systems based on latest technology including Satellite, Radar and numerical models. During the past few years, IMD has been continuously improving weather prediction services in terms of accuracy, lead time and associated impact.

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