The Met Office in Delhi had announced the arrival of the monsoon on Friday, considering a host of factors like wind pattern, pre-monsoon rainfall and the cloud cover over the Arabian Sea.
LS Rathore, director-general, India Meteorological Department, who confirmed the advent of the southwest monsoon, also observed it has been "sluggish" and that "the parameters that support its progress are weaker than their normal positions".
The monsoon's punctuality is crucial to India as it can impact the agricultural belt's plans for sowing crops like paddy, sugarcane, cotton and oilseeds. Once it strengthens in Kerala, the monsoon usually spreads over the entire country by mid-July. Wind profiles over Thiruvananthapuram on Friday morning mapped by the Met department showed that the flurry of westerly monsoon had crossed the tip of the peninsula. This translated into mild but incessant drizzle in the morning and a cloudy atmosphere at noon. Isolated rain cooled most parts of the state.
At the same time, the trough entering south India from further south has become feeble, Met sources said. Remnant winds of this trough are reported to have accompanied the monsoon westerlies, circumambulating over Tamil Nadu. This could bring rain to interior and coastal Tamil Nadu in the next few days.
The course and strength of the southwest monsoon would depend on the cyclonic circulation forecast to take shape on the Arabian Sea. The strength of this cyclonic circulation will determine whether the monsoon spreads across the rest of the country by second week of July.