The monsoon system, forecast to establish itself over Central India by June 15, will be delayed by a week. This is unlikely to affect the overall rainfall in June.
“There is moisture in the air and thunderstorm along with rain…but the monsoon has been delayed [over Central India] because of strong rain in the east,” D.S. Pai, Chief Forecaster, India Meteorological Department, said.
As of June 17, the country got 79.6 mm of rain, 9% more than the average 72.8 mm it receives in the first fortnight of June. Rain in Central India is, in fact, 21% more than what is normal for this time.
In its updated forecast on June 6, the IMD said rainfall was likely to be 96% of the historical average in northwest India, 100% of the LPA (the 50-year average of the monsoon rains) over central India, 99% over the south peninsula, and 96% over northeast India, with a model error of plus or minus 8%.
The IMD said last week that the southwest monsoon had advanced across some parts of Central and eastern Maharashtra, Chhattisgarh, Jharkhand and Bihar, most parts of Odisha, and the rest of West Bengal.
It had reached Karnataka, Goa and the Konkan on the western coast while on the eastern coast it covered Andhra Pradesh, Odisha, parts of Telangana and the North East.
Dynamic forecast
In April, the IMD shifted to using a new monsoon forecast system, called a dynamical model that uses supercomputers to simulate the weather and extrapolating it. This model, reportedly, indicates that monsoon will only hit Central India around the end of this month.
It plans to make this the base for all future forecasts, ranging from short-term weekly projections to the trajectory of the four-month-long monsoon. However, for its June update, the IMD chose to rely on its workhorse statistical model that forecasts the monsoon based on six meteorological parameters.
The dynamical model, according to the IMD statement, showed monsoon rains to be 89 cm or 100% of the LPA.
(With inputs from PTI)
