The Minister of State for Planning, Science & Technology and Earth Sciences Dr. Ashwani Kumar today said that Government is aware of deficit monsoon seasonal rainfall forecast, for June-September, 2012, by certain foreign institutions/departments based on the simulations of dynamical models.
Replying to a question in Rajya Sabha he said that as per the seasonal forecasts issued by the Frontier Research Institute, Japan in February 2012, India is expected to experience below normal rainfall during the coming monsoon season of 2012. However, forecasts from the United States National Centers for Environmental Prediction (NCEP) and United Kingdom Meteorological Office (UKMO) suggest above normal rainfall during the monsoon season of 2012. The present skill of these dynamical models predicting Indian monsoon seasonal rainfall has not yet reached satisfactory levels.
The Minister further stated that the present level of operational acceptability of error margin is of 5% for the forecasts of all-India seasonal monsoon rainfall. The forecast verification of last 3-years suggests that only during 2009 the error margin was higher than 5% due to persistence of warmer sea surface temperature anomaly over equatorial Pacific Ocean (El Nino) beyond the expected duration as envisaged at the time (April 2009) of finalizing Monsoon-2009 seasonal rainfall forecast.
Dr. Ashwani Kumar revealed that currently, IMD uses a suite of statistical models for prediction of seasonal monsoon rainfall over India. Such a mechanism is continued to be used due to non-availability of a suitable coupled ocean-atmospheric model with a proven performance of capturing the realistic monsoon rainfall variability over India.
The Minister assured the House saying that we are examining the performance of coupled ocean-atmospheric models of NCEP, USA and UKMO for their suitability for seasonal monsoon rainfall predictions.