The intra-seasonal variability of southwest monsoon during this season has been large. An early onset, about a week before schedule, was followed by a massive stall in both the arms of the monsoon. However, the accelerated pace after the pause has taken the monsoon current deep over the western and northern plains, once again before the due dates. The monsoon stream has been meandering near the national capital for the last 2–3 days, raising hopes of a record early onset. But the typical onset pattern is evading, and the goalpost is getting shifted incrementally for the last couple of days. In the meantime, prospects are building for a quick march of monsoon to reach the last posts of Rajasthan, much earlier than the normal.
Arrival dates of monsoon were revised in 2019. Prior to that, the monsoon timeline was 15th July to reach the farthest areas of West Rajasthan, like Barmer, Jaisalmer and Phalodi. Following revision, the new date was fixed at 08th July for covering the entire Indian region. True to its reputation, the monsoon rarely follows these stipulated dates and keeps wandering for unknown reasons to defy the dictate. And so is likely to happen this season as well.
The remnant of low pressure from the Bay of Bengal is now marked as a cyclonic circulation over South Uttar Pradesh. Another cyclonic circulation is now marked over West-Central and adjoining Northwest Bay of Bengal, off South Odisha and North Coastal Andhra Pradesh. The east-west trough joining these two features is extending further westward across Central and West Rajasthan. The axis of this elongated trough has a tendency to generate embedded small-scale circulations all along the stretch. These circulations are likely to come up around 26th & 27th June over Central and West Rajasthan. Coincidentally, a western disturbance is likely to come up as an upper-air system over North Pakistan and adjacent border areas of Punjab and Jammu region. This will provide auxiliary support to the multiple weather systems over the area.
The southwest monsoon is likely to cover some more parts of Rajasthan and Punjab, some parts of Haryana, Delhi, Chandigarh and remaining parts of West Uttar Pradesh, Himachal Pradesh and Jammu & Kashmir in the next about 48 hours. After that, only a small portion of West Haryana, South Punjab and extreme western parts of Rajasthan will be left uncovered by the monsoon. With the multiple factors joining hands and working in tandem, the conditions look favourable for a before-time sweep of monsoon over the complete Indian region. There is a large probability of this feat getting achieved in the month of June itself.
