Indian Meteorology Department forecast on monsoon onset to come today

PUNE: The Indian Meteorology Department ( IMD) will issue its forecast for the onset of monsoon, which represents beginning of the rainy season over India, today. As compared to its forecast of rainfall for all of the monsoon season, the forecast of onset date has been accurate during all the nine years, since its beginning in 2005.

IMD started issuing forecast of onset of monsoon at the southern tip of India at the Kerala coast operational using an indigenously developed statistical model that has a model error of ± 4 days. All the forecasts of onset of monsoon have been within the range of the model error. "The accuracy of the onset forecast is more as it is given on a shorter range unlike the seasonal prediction," said DS Pai, the lead forecaster of IMD for India.

After the onset, the monsoon winds cover entire country by July 15. The pace of the progress from the southern tip of the country to its north most point in Rajasthan may vary every year.

Any deviation in the onset time of monsoon can result in significant change in the area of some rain fed crops which need early sowing like moong and urad.