Very Heavy Rain Threat Continues Across Tamil Nadu, Puducherry and Karaikal

Key Takeaways:

• Heavy to very heavy rainfall is expected at isolated places on October 22 and 23, with localized intense spells possible on October 24.
• A low-pressure area over the southwest Bay of Bengal and adjoining Tamil Nadu coast is supporting moisture convergence and thunderstorm development.
• Thunderstorm winds may reach 40–50 kmph, while coastal squalls may gust to 55 kmph on October 22, requiring caution for fishermen, commuters and farmers.
• Forecast Validity: October 22–24, 2026 (next three days), covering Tamil Nadu, Puducherry and Karaikal.

Tamil Nadu, Puducherry and Karaikal face another spell of intense northeast monsoon weather during the next three days. The India Meteorological Department expects heavy to very heavy rainfall at isolated places on 22 and 23 October, with similar localized intensity possible on 24 October. Thunderstorms accompanied by lightning and gusty winds reaching 40–50 kmph are also likely. Urban centres and low-lying coastal areas may experience short-duration waterlogging where strong rain bands repeatedly cross the same locations.

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The wet spell is being sustained by a low-pressure area over the southwest Bay of Bengal and the adjoining Tamil Nadu coast. At 1730 IST on 21 October, the system’s associated cyclonic circulation extended up to 5.8 km above mean sea level. This circulation is drawing moisture from the Bay of Bengal, while converging easterly winds are helping thunderstorms organize over coastal and interior Tamil Nadu. These conditions can produce marked variations in rainfall intensity over relatively short distances.

Fairly widespread to widespread rain is expected through 22 October. From 23 October, the overall distribution may reduce to isolated or scattered showers, but individual thunderstorms could remain powerful enough to deliver very heavy rain locally. The higher-risk period, therefore, continues beyond the reduction in geographical coverage. Puducherry, Karaikal and several parts of Tamil Nadu may receive intermittent rain, with intense spells most likely beneath slow-moving thunderstorms.

Squally weather, with winds of 35–45 kmph gusting to 55 kmph, is expected over the Gulf of Mannar, adjoining Comorin area, and waters along and off south Tamil Nadu and northern Sri Lanka on 22 October. Fishermen should follow the latest coastal advisories and avoid affected sea areas. Lightning and sudden wind gusts may also disrupt outdoor work, ferry operations and road travel during thunderstorms.

Residents should monitor local nowcasts because district-level conditions may change rapidly. Commuters should allow additional travel time, while farmers may need to postpone harvesting, spraying and other exposed field operations during active thunderstorms. Authorities should watch underpasses, poorly drained roads and vulnerable settlements, although widespread flooding should not be inferred from an isolated very-heavy-rain forecast alone.