Press Information Bureau
Government of India
Ministry of Earth Science
27-August-2012 12:57 IST
Monsoon Forecasts by IMD




Monsoon season rainfall for the country as a whole so far till 21st August 2012 has been only to the extent of 85% of its long period average (deficit by 15%) as against normal monsoon outlook issued on


·  26th April, 2012 that has kept at 99±5% of long period average

·  22nd June, 2012 that has kept at 96±4% of long period average and deficient monsoon outlook issued on

·  2nd August 2012 that has kept at < 90% of long period average


            In addition, the monsoon rainfall outlooks issued for four homogeneous regions of the country, monthly outlook for the all India monsoon rainfall for the months of July and August 2012, that are presented below, are also found to be far below the expected scenario





In % of long term average

Issued on 22nd June

Issued on   2nd  August

Actual Rainfall

verification (data from 1st June to   21st August)

Northwest India

June to September

93 ± 8



Central India

June to September

96 ± 8



Northeast India

June to September

99 ± 8



South Peninsula

June to September

95 ± 8



All India


98 ± 9



All India


96 ± 9

96 ± 9





















The deficiency to certain extent is attributed to the delayed onset and advance of monsoon over various parts of the country (in a range of 1-2 weeks). The lower frequency of the formation of principal rain bearing cyclonic weather systems (lows and depressions) over the Indian seas of Bay of Bengal and Arabian Seas during the current season (as against the average frequency of about 6-7, only one low pressure area formed so far) is seen to be the main contributing factor for the deficit rainfall distribution observed over the country. Detailed study on the above seasonal scale monsoon circulation anomalies and associated characteristics are monitored closely to examine their impacts on the ensuing rainfall during the remaining period of August and September, 2012.


The India Meteorological Department (IMD) has so far been using a suite of statistical models for prediction of seasonal monsoon rainfall over India. Such a mechanism is prevalent due to non-availability of a suitable coupled dynamical ocean-atmospheric model with a proven performance of capturing the realistic monsoon rainfall variability over India.  We are examining the performance of coupled ocean-atmospheric models of USA and UK towards their suitability for seasonal monsoon rainfall predictions over India so as to enhance their capabilities under the National Monsoon Mission.


 IMD operates a dedicated weather and climate monitoring, detection and warning services useful for various sectors of economy. Skill of different types of IMD products served by various offices of the department across the nation is presented below:


1.      Average accuracy of short range forecast in recent past is of the order of 70-95%.

2.      Average accuracy of aviation forecast is about 77%.

3.      The accuracy in 24 hours forecasting of cyclone over the north Indian Ocean has increased at the rate of about 7.3 Km per year and the landfall forecast error has decreased at the rate of about 33 Km per year during 2003-2011.

4.      IMD’s onset of southwest monsoon forecast over Kerala has been found correct (within forecast limit) since 2005.

5.      Accuracy of LRF for seasonal rainfall was about 50% during the period 2007-11.

6.      Skill of district level rainfall forecast in 75-85% in monsoon season and more than 85% in non-monsoon season.


         Weather being intrinsically variable, its forecast assessment always have a margin of error and the endeavour of IMD has always been to reduce this margin of error through the use of improved observations and advanced models. It is to mentioned that global weather centre’s also could not predict this years monsoon rainfall deficiency realised so far over India during 2012.


Ministry of Agriculture/Commissionarates of Agriculture in various states carry out weekly review of the current rainfall scenario and outlook for the coming week generated by IMD to assess the ground scenario in support of various crop specific agricultural operations  (from sowing to harvest) under the umbrella of Crop Weather Watch Group (CWWG). The CWWG also assesses the likely yields based on the above of various commodities in each of the crop season that would have bearing on the prices ultimately.  Such exercise is not done on the seasonal monsoon rainfall outlook.


            Expenditure incurred on IMD during last five years are as under:


All figures are in Rs. Crores




























                In agriculture sector alone there is substantial benefit assessed out of the service leading to huge savings as per study conducted by National Council for Applied Economic Research (NCAER) during the period 2009-2010. Considering present level of outreach of 24% of the farmers from the Integrated Agro-Meteorological Advisory Service (IAAS), the financial contribution to the GDP comes to Rs. 44321cr. As and when the extent of IAAS outreach increased to 100%, the GP contribution will rise to about Rs. 184, 671cr.


            Considering the utility and importance of weather and climate based services in all spheres of life, Government is decided to strengthen the IMD to expand and excel its services further through implementation of following prioritized programmes during the XII plan:


1.      Implementation of Phase-II of the modernization of IMD aiming to augment of observational, communication, warning dissemination and modeling infrastructure

2.      Establishment of Airborne Probing of Cyclone (APC) facility to generate the in-situ observations from the cyclone core environment to improve track, intensity and landfall forecasting of tropical cyclones.

3.      Implementation of IAAS as Gramin Krishi Mausam Seva (GKMS) for block level on experimental basis.

4.      Implementation of Monsoon Mission aiming to generate skillful seasonal monsoon rainfall forecast in different spatial ranges.

5.      Implementation of Himalayan Meteorology aiming to augment of observational network over the Hills

6.      Augmentation of Aviation Meteorological Services.


             The above information was given by the Minister of Overseas Indian Affairs, Small & Medium Enterprises, Science & Technology and Earth Sciences, Shri Vayalar Ravi to the Parliament today.