Lok Sabha Question No. 1620 (UNSTARRED), answered on 2021-12-08
Subject: Rain Forecast
Ministry: EARTH SCIENCES
Asked by: Komati Reddy Venkat Reddy

## GOVERNMENT OF INDIA

## MINISTRY OF EARTH SCIENCES LOK SABHA UNSTARRED QUESTION NO. 1620

## TO BE ANSWERED ON WEDNESDAY, 8 TH  DECEMBER, 2021

## RAIN FORECAST

## 1620.      SHRI KOMATI REDDY VENKAT REDDY:

Will the Minister of EARTH SCIENCES be pleased to state:

- (a) whether  the  Indian  Meteorological  Department  (IMD)  can  further  improve  its  models  to forecast shortfall as well as excess rains to help farmers and  others; and
- (b) if so, the details thereof and the progress made so far in this direction and if not, the reasons therefor?

## ANSWER THE MINISTER OF STATE (INDEPENDENT CHARGE) FOR MINISTRY OF SCIENCE AND TECHNOLOGY AND EARTH SCIENCES

(DR. JITENDRA SINGH)

- (a) -(b)   Yes Sir. India Meteorological Department (IMD) in collaboration with its sister organisations in the Ministry of Earth Sciences (MoES) is continuously working on improving operational forecasting models for various weather and climate extreme events and there is always scope for further improvement.

Recognizing the urgent need for improving monsoon prediction capabilities in the country in a systematic  and  timely  manner,  the  Ministry  of  Earth  Sciences  (MoES)  had  launched  an ambitious  and  well-resourced  research  programme  on  mission  mode,  called  the  Monsoon Mission. The first phase of the mission was implemented during 2012-2017 and the second phase  (2017-22)  is  underway.  Through  this  mission,  India  also  augmented  its  capability  of High-Performance Computing (HPC) system, which is close to 10 petaflops capacity now and it is the backbone of the monsoon research and operational services in the country. India has the  fourth  best  computing  facilities  in  the  world  for  weather  and  climate  services.    The Monsoon Mission has helped in the significant improvement of monsoon forecasts in all time scales,  right  from  short-range  to  seasonal.  India  is  now  proud  of  having  one  of  the  best prediction system for generating real time forecasts and warnings in all spatial scales from a location  to  Block,  district,  meteorological  subdivisions  and  homogeneous  regions  and temporal scales of a  few hours (nowcast), 3 days (short range forecast), 4-7 days (medium range forecast) 1-4 weeks (extended range forecast) and one month to a season (long range forecast).

For  preparing  the  long  range  forecast,  currently,  latest  state  of  the  art  statistical  models, Monsoon Mission Coupled Atmosphere Ocean Model (MMCFS) and Multi Model Ensemble (MME)  method  are  used.  And  these  models  have  shown  useful  skill.  For  example,  the operational forecast for the monsoon onset over Kerala has been correct (within the forecast limits)  during  16  of  the  17  years  (2005-2021)  since  issuing  of  operational  forecast  for  the event started in 2005.

## Weather  Forecasting -(Long  range,  Extended  Range,  Short  to  Medium  Range  and Nowcast)

Due  to  demands  from  different  users  and  government  authorities  for  forecasts  of  spatial distribution of seasonal rainfall along with the regionally averaged rainfall forecasts for better regional  level  planning  of  activities,  IMD  has  now  developed  a  Multi-Model  Ensemble (MME) forecasting system based on coupled global climate models (CGCMs) from different global  climate  prediction  and  research  centres  including  IMD ' s  Monsoon  Mission  CFS (MMCFS). Multimodal Ensemble (MME) is a universally accepted technique, which is used to  improve  skill  of  forecasts  and  reduce  forecast  errors  when  compared  to  a  single  modelbased  approach.  The  performance  improvements  are  completely  attributed  to  the  collective information of all models used in the MME forecasting system.

This  year  onwards,  IMD  has  adopted  a  new  forecasting  strategy  for  issuing  monthly  and seasonal  operational  forecasts  for  the  southwest  monsoon  rainfall  over  the  country  by modifying the existing two stage  forecasting strategy.   Accordingly, forecasts  are issued in different stages.   The first stage forecasts issued in the mid-April consist of forecast for the southwest monsoon seasonal (June to September) rainfall over the country as a whole and the spatial distribution of probabilistic forecasts for tercile categories (above normal, normal and below  normal)  for  the  seasonal  rainfall  (June  to  September)  over  the  country.  The  second stage  forecasts  issued  in  the  end  of  May  or  early  June,  consists  of  (i)  update  for  the  April forecasts,  (ii)  Probabilistic  forecasts  for  the  seasonal  rainfall  over  the  four  homogenous regions  of  India  (northwest  India,  central  India,  south  India  and  northeast  India)  and  the Monsoon  Core  Zone  (MCZ)  and  (iii)  probabilistic  forecast  for  the  June  rainfall  over  the country as a whole and spatial distribution of the probabilistic forecasts for the June rainfall over  the  country.  It  may  be  noted  that  MCZ  the  newly  introduced  geographical  region  is essentially  the  central  India  plus  some  additional  areas  covering  most  of  the  rain  fed agriculture  region  in  the  country.  A  separate  forecast  for  the  MCZ  will  be  more  useful  for agricultural planning and crop yield estimation etc.

Subsequently, the forecasts for the July month rainfall is issued in the end of June/ early July and  forecast  for  the  second  half  of  the  monsoon  season  and  monthly  forecast  for  August month are issued in the end of July/ early August. The monthly forecast for the September is issued in the end of August/ early September.

India  Meteorological  Department  follows  a  seamless  forecasting  strategy.  The  long-range forecasts (for the whole season) issued are being followed with extended range forecast issued on  every  Thursday  with  a  validity  period  of  four  weeks.  To  follow  up  the  extended  range forecast, IMD issues short to medium range forecast and warnings at 36 meteorological subdivisions levels daily four times by the National Weather Forecasting Centre (NWFC), New Delhi valid up to next five days with an outlook for subsequent two days.

The short to medium range forecast and warning at district and station level are issued by state level Meteorological Centres (MCs)/Regional Meteorological Centres (RMCs) with a validity of next five days and are updated twice a day. The short to medium range forecast is followed by very short range forecast of severe weather up to three hours (nowcast) for all the districts and 1085 cities and towns. These nowcasts are updated every three hours.

While issuing the warning suitable colour code is used to bring out the impact of the severe weather  expected  and  to  signal  the  Disaster  Management  about  the  course  of  action  to  be taken  with  respect  to  impending  disaster  weather  event.    Green  color  corresponds  to  no warning hence no action is needed, yellow color corresponds to be watchful and get updated information, orange color to be alert and be prepared to take action whereas red color signals to take action.

IMD is issuing Impact Based Forecast (IBF) which give details of what the weather will do rather  than  what  the  weather  will  be.  It  contains  the  details  of  impacts  expected  from  the severe weather elements and guidelines to general public about do's and don'ts while getting exposed  to  severe  weather.  These  guidelines  are  finalised  in  collaboration  with  National Disaster  Management  Authority  (NDMA)  and  is  already  implemented  successfully  for cyclone, heat wave, thunderstorm and heavy rainfall. Work is in progress to implement the same for other severe weather elements.

## Agromet Advisories for Farmers

IMD runs an operational Agrometeorological Advisory Services (AAS) viz., GraminKrishiMausamSewa  (GKMS)  scheme  for  the  benefit  of  farming  community  in  the country. Under the scheme, medium range weather forecast at district level is generated and based on the forecast, Agromet Advisories are prepared and communicated by the Agromet Field Units (AMFUs) located at State Agricultural Universities, institutes of Indian Council of Agricultural Research (ICAR), IIT, etc and also by District Agromet Units (DAMUs) located at KrishiVigyanKendras (KVKs), to the farmers on every Tuesday and Friday to take decision on agricultural operations. AAS rendered by IMD is a step towards weather-based crop and livestock management strategies and operations dedicated to enhancing crop production and food security besides reducing crop damage and loss due to deficient rainfall situation.

Agromet  Advisories  are  communicated  to  the  farmers  through  multichannel  dissemination system  like  print  and  electronic  media,  Door  Darshan,  radio,  internet,  social  media  etc. including SMS  using  mobile  phones  through  Kisan  Portal launched by Ministry of Agriculture and Farmers ' Welfare and also through private companies under Public Private Partnership (PPP) mode. KrishiVigyanKendras (KVKs) of ICAR have also given link to the respective district level advisory in their web portal. A mobile App viz., ' Meghdoot ' has been launched by Ministry of Earth Sciences, Government of India, to help the farmers to get the weather information including alerts and related  agromet advisories specific to their districts.IMD  also  monitors  rainfall  situation  &  weather  aberrations  and  issues  alerts  & warnings  along  with  suitable  Agromet  Advisories  to  the  farmers  from  time  to  time  under GKMS scheme.

For  modernization,  expansion  and  improvement  in  Weather  &  Climate  services,  various activities are underway in IMD under the Central Sector umbrella Scheme ACROSS. There are  4  sub-schemes  of  IMD  under  Atmosphere  &  Climate  Research-Modelling  Observing Systems &  Services (ACROSS)  namely, Atmospheric Observation Network (AON), Upgradation of Forecast System (UFS), Weather & Climate Services (WCS) and Commissioning of Polarimetric Doppler Weather Radars (PDWR).

Moreover , v arious  new  initiatives,  as  mentioned  below,  have  been  undertaken  by  IMD, MoES for betterment of prediction and dissemination of warnings of extreme weather events that may cause natural disasters.

1. The observational network of the department is being enhanced across the country.
2. 29  Doppler  Weather  Radars  are  operational  across  the  country  to  provide  adequate warning in the event of approach of Cyclonic Storms, Monsoon Depressions, Thunderstorms  etc.  DWR  network  also  provides  vital  information  for  nowcasting purposes on mesoscale convective weather developments anywhere in the country.
3. Multi-Mission Meteorological Data Receiving & Processing System has been established and dedicated to the nation for augmentation of satellite derived products.
4. Location specific forecast for 7 days within the capital cities and nowcast for next 3 hours have  been  extended  to  526  and  1084  stations  respectively  covering  739  districts  in  the country.
5. NWP Model based gridded rainfall data are provided to Central Water Commission for their  flood  forecasting  model  for  all  153  river  catchments  and  Extended  Range  model products for 10 river basins.
6. With operationalization of  Flash  Flood  Guidance  system,  generation  and  issue  of  Flash Flood Guidance has commenced for all watersheds of the country.
7. Impact based forecast is already in practice for cyclone. The same is extended to heavy rainfall and heatwaves. Efforts are on to extend the same to all types of severe weather.

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