Thunderstorm activity over the south of the country will flare up further as equatorial Indian Ocean around Sri Lanka pipes in fresh fuel in the form of moisture.
Thundershowers will grow over peninsular India along the south-west coast, but the eastern part (Seemandhra, parts of Telangana and north Tamil Nadu) will need to wait for another week.Gujarat parched
The week beginning May 6 will see a further increase in thunderstorm activity covering entire south even as a perpendicular wave of thundershowers invades north-west, east and north-east India.
Gujarat and adjoining western Madhya Pradesh are likely the two regions not benefiting from either of these waves through the two weeks in what is otherwise a good build-up to the monsoon.
But it is a given that sustained thundershowers in the northwest will cap the heating of the land which could pour cold water over the prospects of timely onset of monsoon showers later.
Heating through the month of May and June is crucial for setting up suitable temperature and pressure gradients from the south-west (Kerala) coast.
This sets up the highway for the Arabian Sea arm of the monsoon to ride along the west coast, meet the Bay of Bengal arm over central India and proceed to cover the entire landmass during June to September.Heating process
Leading international models suspect if the northwest can heat up and sustain the levels at 48- to50 deg Celsius long enough to set up the gradient.
India Met Department on Tuesday indicated that the heating process is on in parts of west Rajasthan with Barmer touching 45 deg Celsius only the previous day.
It has predicted that heat wave conditions may prevail over Rajasthan and Uttar Pradesh over the next couple of days. The footprint of the heat wave is then forecast to shift to the east. The Met has also forecast the arrival of another western disturbance, a low-pressure wave from across the border capable of triggering thunderstorm or hail, later during the week.