New Delhi / Thiruvananthapuram: The low-pressure system that crossed the northern Andhra Pradesh coast recently is expected to weaken significantly within the next 24 hours, paving the way for the rapid withdrawal of the Southwest Monsoon across India.

Currently situated as a deep depression near Fatehpur and Farsatganj in Uttar Pradesh, the system is bringing active rainfall to parts of Delhi and Uttar Pradesh. However, as it degrades into a standard low-pressure area over the next day, the barrier holding back the monsoon's retreat will clear, allowing the withdrawal process to move steadily into Southern India by the end of the month.

Wind Shift Expected from October 1

Global weather models indicate a major shift in wind patterns starting October 1. Low-level atmospheric winds are projected to pivot to a northeasterly and easterly direction over Peninsular India, bringing active thunderstorm activity to southern states.

While an official announcement regarding the complete exit of the Southwest Monsoon is expected during the first week of October, conditions are fast aligning for an early declaration of the Northeast Monsoon (Tulavarsham).

IMD Criteria for Northeast Monsoon Arrival

The India Meteorological Department (IMD) officially declares the onset of the Northeast Monsoon over Southern Peninsular India covering Tamil Nadu, Puducherry, coastal Andhra Pradesh, Rayalaseema, Kerala, and south interior Karnataka when the following benchmarks are satisfied:

Complete Southwest Monsoon Exit: Total withdrawal of the Southwest Monsoon from Northern and Peninsular regions.
Sustained Wind Reversal: Continuous flow of lower-tropospheric winds from the northeast or east.
Widespread Coastal Rain: Onset of widespread rainfall along the coasts of Tamil Nadu, Puducherry, and South Andhra Pradesh.
Consistent Station Rainfall: Rain gauge stations recording persistent rainfall over 1 to 2 consecutive days.

While the Northeast Monsoon typically arrives between October 15 and October 20, the IMD may declare its arrival anytime after October 1 if these atmospheric conditions are fulfilled.