Southwest monsoon has withdrawn from the plains of north India, covering West Rajasthan, Punjab, Haryana, Delhi, Chandigarh and neighbouring parts of West Uttar Pradesh and West Madhya Pradesh. The withdrawal line is likely to extend further to retreat from parts of Gujarat, East Rajasthan, West Madhya Pradesh and more parts of Uttar Pradesh. The withdrawal from the country is generally complete by the 15th of October. Simultaneously, the precursors to the northeast monsoon start appearing but still remaining as part of southwest monsoon with short bursts of rainfall over the central and southern parts.
There is a cyclonic circulation over Lakshadweep region and adjoining Arabian Sea. Also, there is a cyclonic circulation on the other side of the coastline over the Bay of Bengal. A trough is extending almost along the coastline of Odisha, Andhra Pradesh and North Tamil Nadu. A proper cyclonic circulation is likely to appear over Southwest Bay of Bengal, off South Andhra Pradesh and North Tamil Nadu on the 05th/06th of October. Under the influence of these features, South Peninsular India will find an uptick in weather activity between 04th and 09th October. Scattered rainfall is expected even today over parts of Karnataka, Rayalaseema, Tamil Nadu and Kerala.
While the circulation over Lakshadweep will shift northward to get placed abeam Goa coast, the other circulation over the Southwest BoB will come closer to the landmass. An east-west shear line will connect these two features and trigger rainfall activity over the Peninsular India. This activity will remain a part of southwest monsoon and act as precursor to the northeast monsoon, arriving later in the month. Almost all the southern sub divisions, namely Rayalaseema, North & South Interior Karnataka, Coastal Karnataka, Tamil Nadu and Kerala will get their share of activity, under the combined influence of these multiple features. The activity is likely to ease out after 11th October to make way for the withdrawal of monsoon by middle of October.
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