The monsoon made a weak onset over Kerala on Friday with only one centre in Kasaragod district recording a heavy rainfall of 8 cm during the 24 hours ending in the morning.
The local Met office said, however, that moderate rain of varying amounts was reported from most places in Kerala and Lakshadweep.
A warning valid for fishermen said winds speeding up to 55 km/hr are likely until Saturday evening. For the first time in 10 years, the onset happened outside of the time band set four days to the either side of the May 30 median.
The outer limit of this band had lapsed on Wednesday (June 3).
Shows up again A persisting anti-cyclonic circulation in the Arabian Sea had been working at cross-purposes with the timely arrival of the monsoon, according to experts.
An array of western disturbances passing just to the north over Pakistan and north-west India only helped sustain the circulation, offering strong resistance to the monsoon flows.
In fact, the circulation showed itself up prominently on the day the monsoon onset was announced, parked just to the northwest of a ‘trough’ over Lakshadweep. In the process, it has delayed the formation of a crucial low-pressure area here by two more days, the Met said.
The monsoon requires a ‘low’ or a similar weather system to push the rains along the coast and into interior peninsula.
Even assuming that it materialises, the ‘low’ will not be allowed to gather significant strength.
It will be allowed to move north towards the Mumbai coast by June 12, as per Met forecasts.
Spell in East It would strong monsoonal flows and heavy rain into coastal Karnataka, Konkan-Goa, Mumbai and adjoining south Gujarat during this phase.
According to the US Climate Prediction Centre, the monsoon will bring heavy rainfall over the south peninsula until June 10. The north-eastern States also will receive heavy rain during this phase.
The following week is likely to see a spike in rain over Mumbai and neighbourhood while the monsoon spreads out over east and north-east India.
The north-eastern States, including eastern parts of Gangetic West Bengal, will go under a punishing spell during the week, the US forecasts said.
But the west coast is seen quietening down a bit with below normal rainfall until June 17. The Indian Institute of Tropical Meteorology in Pune agrees with this outlook.