The continuous heating in northwest and central parts of the country could work as a catalyst to pull the weather system that is building up in southeast Arabian Sea to give first showers of monsoon over Kerala coast at the start of next week. Skymet weather models show that monsoon rain is expected to arrive in Kerala coast by as early as 28th of the month, two days before the due date of 1st of June.
Weather conditions in India are also becoming more suitable for monsoon as the days progress. The heating in northwest and central India has led to the possibility of formation of a low pressure area in central India that could invite the weather system hovering over southeast Arabian Sea to touch the Kerala shore.
The monsoon has already arrived in the Andaman & Nicobar Islands three days before the due date. The northern limit of monsoon (NLM) continues to pass through Lat 5.0°N/Long 82.0°E, Lat.10.0 °N Long. 86.0°E, Lat. 13.0°N/Long.91.0°E and Lat.16.0°N/Long.95.0°E.
The other reason for the early monsoon is the absence of a strong Western Disturbance over north India that usually brings down the temperature to deny the formation of low pressure which is vital for pulling the weather inland from the sea. No such strong Western Disturbance is in sight other than one on the 24th of May, a weather system that is expected over Jammu & Kashmir.
Westerly to southwesterly wind conditions in south Peninsula also suggest that the weather system in southeast Arabian Sea may inch towards Kerala coast. Pre-monsoon rain will continue in Kerala, south interior Karnataka and Tamil Nadu under the trough of low pressure that runs from east Uttar Pradesh to south Tamil Nadu during the next two days.
Rain is expected over east in West Bengal and Sikkim and over northeastern states during the next two days. A trough of low pressure runs from east Assam to north Bay of Bengal across Tripura. One or two places over Bihar, Jharkhand, Orissa, Chhattisgarh and Andhra Pradesh may receive rain during this period.
Wind conditions in northwest India have changed in the last two days and now southwesterly winds are reaching Delhi during nights. With rise in moisture levels, discomfort could increase in the capital during the night as temperatures will also be warm at over 30 degrees. Westerly winds during the day would continue to keep the temperature in Delhi around 45 degrees.