"India Meteorological Department's long range forecast for the 2012 southwest monsoon season (June-September) is that the rainfall for the country as a whole is most likely to be normal. Quantitatively, monsoon season rainfall is likely to be 99 percent of the long period average (1951-2000)," said Deshmukh.
According to IMD, there is very low probability for the season's rainfall to be deficient, which is below 90 percent, or excess, which is above 110 percent.
However, the probability of season rainfall to be below normal (between 90-96 percent) is higher at 24 percent.
In 2011, monsoon rainfall was 102 percent of the average.
According to the IMD, the factors affecting southwest monsoon seem to be normal as of now and anything concrete can be said only by mid-May.
When asked about the expected dates of onset of monsoon, Shailesh Nayak, secretary ministry of earth sciences, said: "It is too early to say anything but normally, the southwest monsoon onsets on Kerala on June 1."
The IMD also announced normal rainfall in rice producing states. IMD will update the forecast in June as part of the second stage forecast.
Along with the updated forecast, separate forecasts for the monthly (July and August) rainfall over the country as a whole and seasonal (June-September) rainfall over the four geographical regions of India will also be issued.
Replying to a question about the unusually cool April this year, IMD director general L.S. Rathore said: "It is due to western disturbance and it won't have any impact on the monsoon."
This year for the first time dynamical model along with statistical models was used for weather forecasting.