To better its monsoon forecast, the India Meteorological Department (IMD) will use the multi-model ensemble approach and also give a monthly outlook for the four months of the rainfall season, its director general said on Monday.
The IMD will also give a flood warning forecast to the Central Water Commission for five days, IMD DG Mrutunjay Mohapatra added.
It currently gives flood forecasts for three days.
Addressing a day-long seminar on ‘Annual Monsoon E-Workshop and National E-symposium on Cloud Precipitation, Mohapatra admitted that the forecast for Southwest Monsoon, 2020 was not accurate.
The seminar was attended by senior scientists of the Ministry of Earth Sciences institutions and senior meteorologists of the IMD.
On the monsoon forecasts for 2021, Mohapatra said, “We will be using the multi-model ensemble approach for forecasting Southwest Monsoon 2021.”
This will include other dynamical models, which give weightage to different parameters while issuing forecasts.
Currently, forecasts are made using the Monsoon Mission Coupled Forecasting System (MMCFS) and Statistical Ensemble Forecasting System (SEFS).
“We will also try to give monthly forecasts for all the four months of monsoon,” Mohapatra added.
June to September are, officially, the rainfall months of the country.
Currently, the IMD does not give a forecast for June. However, it does give forecasts for every two weeks.
June being the sowing week in many parts of the country, the IMD is aiming to provide forecasts for June as well as the other three months.
The IMD had made a forecast of normal rainfall last year but the country received above normal rainfall.
“The seasonal forecast assessment was not that good. We could sense the trend that it is going to be a good year but quantitatively, (but) the forecast performance was not accurate as expected with respect to seasonal rainfall. “Similarly, with respect to rainfall during July and August, we could not predict well. It was beyond the error limit. Except the onset for the monsoon forecast, other forecasts went wrong for the season,” Mohapatra said.