Lok Sabha Question No. 1 (STARRED), answered on 2018-07-18
Subject: Monsoon Prediction
Ministry: EARTH SCIENCES
Asked by: ASHOK SHANKARRAO CHAVAN, SUDHEER GUPTA

## GOVERNMENT OF INDIA MINISTRY OF EARTH SCIENCES LOK SABHA

## STARRED QUESTION No.*1

## TO BE ANSWERED ON WEDNESDAY JULY 18, 2018

## MONSOON PREDICTION

- *1. SHRI ASHOK SHANKARRAO CHAVAN: SHRI SUDHEER GUPTA:

Will the Minister of EARTH SCIENCES be pleased to state:

- (a) whether the India Meteorological Department (IMD) has predicted normal monsoon during the current season and if so, the details thereof, region-wise;
- (b) whether the Government is aware that several foreign agencies including the Japanese Meteorological Department have predicted below normal monsoon during the current season;
- (c) if  so,  the  details  thereof  and  the  reaction  of  the  Government thereto, agency-wise;
- (d) whether  average  error  in  IMD's  monsoon  forecasts  has  come down during each of the last three years and if so, the details thereof; and
- (e) the  measures  taken/being  taken  by  the  Government  to  update the  IMD  system  as  well  as  to  avoid  inaccurate  predictions  by IMD?

## ANSWER

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

- (a) to (e):  A statement is laid on the Table of the House.

## STATEMENT REFERRED TO IN REPLY TO PARTS  (A)  TO  (E)  OF  THE  LOK SABHA STARRED QUESTION NO. *1 REGARDING 'MONSOON PREDICTION' FOR ANSWER ON 18 TH  JULY, 2018.

- (a) Yes Madam.  IMD has predicted a normal monsoon during the current season (2018 southwest monsoon season). The summary of the forecast issued on 30 th  May, 2018 is given below and detailed forecast is attached as Annexure-I.
-  Rainfall  over  the  country  as  a whole  for  the  2018  southwest monsoon  season  (June  to  September)  is  most  likely  to  be NORMAL (96% to 104% of long period average (LPA)).
-  Quantitatively,  monsoon  season  (June  to  September)  rainfall for the country as a whole is likely to be 97% of the LPA with a model error of ±4%.
-  Region wise, the season rainfall is likely to be  100% of LPA over North-West India, 99% of LPA over Central India, 95% of LPA  over  South  Peninsula  and  93%  of  LPA  over  North-East India all with a model error of ± 8 %.
-  The monthly rainfall over the country as whole is likely to be 101%  of  its  LPA  during  July  and  94%  of  LPA  during  August both with a model error of ± 9 %.
- (b) Government  is  aware  that  several  foreign  climate  prediction agencies including Japan Meteorological Agency (JMA) prepare and issue forecasts of seasonal rainfall and IMD has access to these  forecasts.    However,  it  may  be  mentioned  that  in  the month of May when IMD issued the Long Range Forecast, most of the model forecasts including that from JMA were indicating normal rainfall during the 2018 southwest monsoon season and not below normal rainfall. The details of the forecasts issued by other agencies are given in the Annexure-II:
- (c) Does not arise.
- (d) Yes madam. The absolute error of the IMD's monsoon forecasts for the seasonal rainfall over the country has shown significant decrease after the implementation of the new statistical ensemble  forecasting  system  in  2007  compared  to  previous years.  The average absolute error (difference between forecast and  actual  rainfall)  of  the  new  statistical  forecasting  system used  for  forecasting  all  India  rainfall  during  the  last  11  years (2007 -2017) was 5.9% of long period average (LPA) compared to the average absolute error of 8.5% of LPA during the previous 11 years (1996 -2006).  This clearly indicates improvement made in the operational forecast system in the recent period compared to the earlier period.   It may be mentioned that IMD was able to correctly  predict  the  deficient  monsoon  rainfall  experienced during 2014 & 2015.
- (e) Government  has  taken  several  measures  to  upgrade  the  IMD forecast system to further improve prediction accuracy. Systematic efforts are being made to further improve statistical forecasting system, which was introduced by IMD in 2007. Under the  Monsoon  Mission,  a  new  dynamical  prediction  system  for long range forecasting of Indian monsoon was implemented by IMD.    IMD  is  working  to  improve  the  skill  of  this  dynamical prediction system  in  collaboration with Indian and  foreign academic institutions.

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## Annexure-I

## Annexure -II

Inferences  derived  from  seasonal  forecasts  from  various  climate  prediction agencies for the 2018 southwest monsoon season.

|   S. No | Forecasting Agency                                               | Inference for 2018                                                                                                                                                                                                                                                                                                                                  |
|---------|------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
|       1 | European Centre for Medium Range Weather Forecasting (ECMWF), UK | June-August & July to September (Issued: May 2018): Normal to above normal rainfall is likely over parts of North, Central and Northwest India. Normal to below normal rainfall is likely over parts of Northeast and South Peninsular India.                                                                                                       |
|       1 | European Centre for Medium Range Weather Forecasting (ECMWF), UK | June to August and July to September (Issued: May 2018): Normal rainfall is most likely over the most parts of the country. However, above normal rainfall is likely over some parts of east central and below normal rainfall is likely over southernmost parts of the country.                                                                    |
|       2 | International Research Institute for Climate and Society, USA    | June to August & July to September (Issued: May 2018):Above normal rainfall is likely over some of the north and central parts of India. Below normal rainfall is likely over some parts of south peninsular and north-eastern India. For the rest of the country                                                                                   |
|       3 | Japan Agency for Marine-Earth Science and Technology (JAMSTEC)   | climatological probabilities are likely. June to August (Issued: May 2018): Positive rainfall anomalies are predicted over most parts of north, north east and east central as well as south eastern and west (coastal region) India. Negative rainfall anomalies are predicted over remaining areas with highest magnitudes over northwest India.  |
|       4 | APEC Climate Center, South Korea                                 | June, July, August & September (Issued: May 2018): Above normal rainfall likely over the parts of the central and eastern India. Below normal rainfall is likely over parts of south and northeast India. Normal to below normal rainfall is likely over parts of northwest India. Climatological probabilities are likely for rest of the Country. |
|       5 | Met Office, UK                                                   | June to August & July to September (Issued: May 2018): Normal to below normal rainfall is likely over most parts of the country.                                                                                                                                                                                                                    |

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|   6 | World Meteorological Organization LRFMME   | June to August (Issued: May 2018): Above normal rainfall is likely over east-central parts of the country and north Indian region. Below normal rainfall is likely over northeastern part of the country and peninsular region. June to September (Issued: May 2018): Positive rainfall anomalies are predicted over central Indian region. Negative rainfall anomalies are predicted over parts of northeastern and peninsular region of the country.   |
|-----|--------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
|   7 | Japan Meteorological Administration (JMA)  | July to September (Issued: June 2018) Normal to above normal rainfall is most likely over most parts of the country.                                                                                                                                                                                                                                                                                                                                     |