Northeast monsoon to commence Thursday

AK Srivastava, head, climate monitoring and analysis group at IMD, Pune, said, “La Nina conditions are expected to prevail until the end of the year before neutral SST reach neutral. Tamil Nadu may receive slightly below normal rainfall during the upcoming season.”

AFTER A delay of nearly one week, the northeast monsoon is all set to hit the southern peninsula along the east coast on October 26. A press release, issued by the India Meteorological Department (IMD) on Monday, stated that conducive atmospheric conditions, coupled with further withdrawal of the southwest monsoon, were likely over the remaining parts of Maharashtra in the next 48 hours.

This year, the northeast monsoon was expected to be normal, with rainfall expected between 89 per cent and 111 per cent of the Long Period Average (LPA). Northeast monsoon is the lifeline of Tamil Nadu, which receives 70 per cent of its annual rainfall during this season, between October and December.

With conditions of La Nina still looming over the Pacific Ocean, meteorologists said below normal rains were likely over Tamil Nadu.

La Nina is a phenomenon when the Sea Surface Temperatures (SST) of the Pacific Ocean remain cooler than normal. It is known to not favour the northeast monsoon. Such conditions have been existing since August.

AK Srivastava, head, climate monitoring and analysis group at IMD, Pune, said, “La Nina conditions are expected to prevail until the end of the year before neutral SST reach neutral. Tamil Nadu may receive slightly below normal rainfall during the upcoming season.”

Last year was one of the worst seasons for the southern peninsula, especially for Tamil Nadu (-66 per cent deficiency), which suffered “severe droughts”. Similarly , South Interior Karnataka (-70 per cent), Rayalseema and coastal Andhra Pradesh (-66 per cent), Kerala (-62 per cent).

Most of the southern states received very good rainfall during the recently concluded season, especially Tamil Nadu which ended on a 31 per cent excess. Meanwhile, Srivastava said, “After a bad season last year, the already received rains will only make up for the existing deficiency. This will be a very crucial season for Tamil Nadu.”