New Delhi, May 21 -- Conditions are likely to become favourable for monsoon onset over Kerala during next 4-5 days, India Meteorological Department said on Tuesday. The normal date for monsoon onset over Kerala is June 1. Conditions are also likely to become favourable for further advance of southwest monsoon over some more parts of South Arabian Sea, remaining parts of Maldives and Comorin area; some parts of Lakshadweep area, Kerala, Tamil Nadu; some more parts South and Central Bay of Bengal, Northeast Bay of Bengal and some parts of northeastern states during the same period, IMD has forecast. HT reported on Tuesday that May has seen unusual weather in India, marked by frequent thunder- and dust-storms and below normal maximum temperatures over most parts of the country, but experts are convinced that this anomaly will not affect the onset of the Southwest Monsoon, which is expected to arrive early. One important factor for a normal monsoon over the country is formation of a so-called "heat low" over Northwest India. This creates a trough of low pressure that sucks moist air from the monsoon trough . In the absence of this, the monsoon may be deficient. Right now, there is no heat-low. But IMD and independent scientists have said monsoon will arrive before its normal arrival date. An upper air cyclonic circulation is likely to form over eastcentral Arabian Sea off Karnataka coast around May 21. Under its influence, a low pressure area is likely to form over the same region around May 22. Thereafter, it is likely to move northwards and intensify further, IMD said on Tuesday. "The cyclonic circulation will help or favour monsoon onset. All the criterion for monsoon onset including continued rainfall over a large area, increase in cloudiness, westerly winds blowing at 15 miles per hour etc are expected to be met in the next 4-5 days as per our models. The cyclonic circulation may help with these," said M Mohapatra, director general, IMD....