Weathermen see clouds over monsoon onset date

The onset of southwest monsoon over Kerala is likely to be delayed and it is likely to arrive by June 4 instead of June 1, the India Meteorological Department (IMD) said on Tuesday. Private weather forecaster Skymet, however, predicted the onset date to be June 7, with an error margin of three days.

“This may not augur well for kharif sowing,” Skymet said, adding that the onset of monsoon will be delayed, and the advancement will be slightly sluggish over Peninsular India while hot weather will continue deep into June over central and northern parts of the country.

The southwest monsoon normally sets in over Kerala on June 1, with a standard deviation of about seven days. “While the impact of a slight delay in monsoon would not be material, the occurrence of an El Nino may impact the agricultural output and rural income,” rating agency ICRA said. “The impact will be stronger on sectors which are dependent upon agricultural output (for instance, edible oil, sugar, cotton spinning mills) and those that derive a significant portion of their demand from rural income (for eg tractors, two-wheelers, cement).”

Skymet said a powerful cyclone ‘Fabien’ is moving over the South Indian Ocean in the equatorial latitudes, abeam Southern Peninsula restricting the cross-equatorial flow and the build-up of the monsoon stream. In addition, it said, the Arabian Sea continues to host an anticyclone over the central parts in the lower levels of the atmosphere which acts as a deterrent for the smooth streaming of monsoon flow from the Arabian Sea to the West Coast.

The southwest monsoon, which occurs in India from June to September, accounts for 70% of the year’s rainfall and hence is key to the country’s economic well-being and keeping inflation under control. Adequate rains help boost crop output and lower food prices in the country where most of the farmland is rain-fed.

In April, the IMD had predicted a “normal” monsoon for this year, with rainfall during the June-September season likely to be 96% of the longterm average, with an error margin of 5%. However, Skymet has predicted a “below-normal” southwest monsoon, with 60% chance of drought, citing El Niño conditions – a weather phenomenon that has often disrupted monsoon rain in India.

The IMD said the El Niño impact may be felt in the second half of the season, clarifying that all El Niño years were not bad monsoon years.

According to the department, during the monsoon this year, many areas of peninsular India and adjoining east-central India, the east, northeast and parts of northwest are likely to get normal rains. Normal to below-normal rainfall is likely over some areas of the northwest, parts of west-central and some pockets of the northeast, it said.

The onset of southwest monsoon over Kerala is an important indicator for transition from hot and dry season to a rainy season. However, there is no direct correlation between the onset of monsoon and its pace of progress.