Rains to resume in Tamil Nadu as Easterlies return

Cyclone Dana impact on easterlies and rainfall

The formation of cyclone Dana, which made landfall over Odisha, temporarily disrupted the easterly flow over South Peninsular India. This shift brought down dry northern winds, leading to a brief spell of drier weather in the region.

Rains expected to resume over Tamilnadu coast:

With the easterly winds beginning to realign, rainfall is set to return along the Tamil Nadu coast starting tomorrow.

Chennai and its neighboring areas witnessed an isolated freak rain event today, with some western locations recording over 100mm within an hour, while few coastal areas saw only minimal rainfall of around 2-10 mm.

Synoptic feature:

An upper air circulation has also developed over Gulf of Mannar. This circulation is expected to push moist easterlies over Tamil Nadu’s coastal areas, bringing back rainfall from October 31 or November 1. Scattered rains likely over coastal areas of Tamilnadu with heavy rains possible in South and central Tamil Nadu during next 4-5 days.

Forecast for KTCC Region:

In the next 4-5 days, coastal areas of Kanchipuram, Thiruvallur, Chengalpet, and Chennai (KTCC) districts will see rain mostly during night time and early morning, while inland areas will experience thunderstorms in the afternoon.

Strong easterly wave to affect TN coast next week.

Starting November 5, a stronger easterly wave embedded in a trough could lead to widespread heavy to very heavy rainfall across Tamil Nadu and South Andhra Pradesh. More on this will be updated soon

Northeast Monsoon Performance Update:

Since October 1st, the Northeast Monsoon has performed well, with Tamil Nadu receiving 212 mm of rain, 29% above the average of 165 mm for this period. Chennai alone has recorded 350 mm, 34% higher than the average of 260 mm to date.

Numerical weather and climate models predict this trend will continue, with the MJO (Madden-Julian Oscillation) expected to enter favorable phases in early November, enhancing rainfall across southern Peninsular India and likely leading to vigorous Northeast Monsoon activity by the end of the first week of November.

Further updates will follow as the weather event nears