Heavy rainfall exceeding 7 cm has been forecast at isolated places in Kerala until Tuesday morning but prevailing meteorological conditions did not offer a clue on the dynamics of the incoming monsoon.
India Met Department has warned of strong winds from south-westerly direction speed reaching up to 45- to 55 km/hr in speed along and off Kerala coast during this period.
There is an acceptable change in wind direction closer to the Kerala but it would not sustain for sufficiently long to be of any significance to the monsoon onset scenario.
The US Climate Prediction Centre sees a steady wet regime materialising along the West Coast from the south-west (Kerala) from Saturday and growing to the North along the coast.
The peninsular interior is also shown as getting covered in what looks like the piloting rains leading the rest of the monsoon caravan into Kerala coast anytime during the next week.
The triggering mechanism could lie in a weather disturbance apparently taking shape over Maldives, as per the Climate Forecast System model of the US agency.
Cloud cover This is corroborated by the forecast of negative values of outgoing long-wave radiation (OLR) from a region extending to the east of Maldives and covering Sri Lanka and adjoining seas from Thursday.
Negative OLR values indicate enhanced convection and cloudiness in the region, which is supportive for the formation of a weather system capable of pumping up moisture and triggering rain.
This however would be accompanied by a let-up in the intensity monsoon flows over the Bay of Bengal, which is holding strong currently.
Meanwhile on Monday, heat wave conditions prevailed over north-west, west and central parts, which are forecast to migrate to adjoining peninsula over the next few days.
Heat wave An IMD update said on Monday that day temperatures would rise over Karnataka and Andhra Pradesh leading to building up of heat wave conditions over Telangana and coastal Andhra Pradesh from Thursday.
This will be matched in the north-west by raging dust storms kicked up after a western disturbance sets up meeting with prevailing surface winds from east India.
Simultaneously, there will be a mark-up in the intensity of thunderstorm activity in northeast India as strong south-westerly monsoon winds across the Bay of Bengal batter the region and get deflected by the Himalayas.
The southern flanks of the wind regime would force themselves on and pour rain over the Bay of Bengal rim comprising Bangladesh, Myanmar, and southwest Thailand.