Heavy rainfall hits Tamil Nadu, IMD issues alert for next 3 days as rain-triggered mudslide kills 1 in Nilgiris

The IMD forecast an active three-day spell as the northeast monsoon intensified over Tamil Nadu. The warning mattered because heavy rain can quickly disrupt roads, settlements and transport, especially in hilly districts. Temperatures, however, were expected to remain near normal until October 28.

On October 25, isolated extremely heavy rain was expected in Theni, Dindigul and Madurai. Heavy to very heavy rain was forecast across districts including Cuddalore, Nagapattinam, Thanjavur, Tiruchirappalli, the Nilgiris, Coimbatore and Sivaganga. On October 26, isolated heavy to very heavy rain was expected in Sivaganga, Ramanathapuram and Pudukkottai.

Rain was expected to ease in many areas on October 27, with isolated heavy rain in Ramanathapuram and light rain elsewhere. At the same time, a cyclonic storm was likely to form over the west-central Bay of Bengal and move toward the Andhra Pradesh coast. Nine ports hoisted warning signals, while Chennai and its suburbs could still receive moderate to heavy rain.

A mudslide is a downhill movement of wet soil, mud, rocks and other debris. It happens when a slope loses stability. Intense rainfall is a major trigger because water enters the ground, fills spaces between soil particles and makes the slope heavier. It can also wash away supporting soil near roads and stream channels.

The Nilgiris incident shows the danger clearly. Very heavy rain triggered multiple mudslides on the route from Coonoor to Mettupalayam. One slide buried a government bus and killed its driver, Janagaraj. The conductor, Kesavan, was rescued from neck-deep slush. More than 100 students travelling behind the bus escaped after their vehicles stopped about 300 metres away.

The immediate danger is burial, injury and isolation. Mud can cover roads faster than crews can clear them and may damage bridges, drains and road edges. The article reports blocked Ooty-Mettupalayam and Ooty-Coonoor highways. Authorities therefore closed vulnerable ghat routes, suspended mountain trains and advised tourists to avoid the Nilgiris for three days.

The worst-affected Nilgiris locations recorded substantial rainfall within the preceding period. Burliar received 25 cm, the highest figure listed. Kil Kotagiri Estate recorded 20 cm, Coonoor PTO 17 cm, Alakarai Estate 16 cm, Mettupalayam 15 cm and Kothagiri 14 cm. These totals help explain why slopes and roads became dangerous.

The rain triggered multiple mudslides. More than 200 vehicles were stranded along the mountainous highway. More than 100 students from Kerala were travelling home to Palakkad, and at least two buses carrying them were later stranded. The students were evacuated in minibuses to Mettupalayam, where food and shelter were provided.

The article does not give a single numerical count of affected routes. It names the Ooty-Mettupalayam and Ooty-Coonoor highways, says Batlagundu-Kodaikanal traffic was affected, and reports problems on the Bodimettu Ghat Road. Authorities also closed vulnerable ghat routes overnight and suspended mountain train services.

The rain caused both immediate danger and widespread transport disruption. A government bus travelling from Coonoor to Mettupalayam was buried by mudslides, killing driver Janagaraj. Conductor Kesavan was rescued from neck-deep slush and taken for hospital treatment. More than 100 students escaped because their vehicles stopped about 300 metres behind the bus.

At least two buses carrying those students were later stranded. Minibuses safely took the students to Mettupalayam, where officials arranged food and shelter. More than 200 vehicles remained stranded along the mountainous highway. Mudslides blocked the Ooty-Mettupalayam and Ooty-Coonoor highways, and damaged roads affected travel between Batlagundu and Kodaikanal.

In Krishnagiri, flash floods washed away a temporary causeway near Sauttahalli Kottai. More than 100 families then struggled to access the village. Residents had contributed ₹8 lakh to build the causeway the previous year after repeated flooding, while they continued demanding a permanent bridge. Tourist spots and vulnerable routes were closed in the Nilgiris.

Mountainous areas are especially vulnerable because roads often cross steep slopes and narrow valleys. Gravity constantly pulls soil and loose rock downhill. When intense rain enters the ground, the soil becomes heavier and less stable. Fast runoff can also erode the slope below a road, removing the support that keeps it in place.

The Nilgiris experienced this chain of events during the heavy rain. Multiple mudslides blocked the Ooty-Mettupalayam and Ooty-Coonoor highways. More than 200 vehicles were stranded, while traffic between Batlagundu and Kodaikanal was affected by damage to arterial roads. Similar incidents occurred in Kodaikanal and on the Bodimettu Ghat Road.

The result is more than a blocked lane. Rescue vehicles, buses, tourists and supplies can become trapped, while alternative routes may also be unsafe. Authorities closed vulnerable ghat routes between 6 pm and 7 am, suspended mountain train services, shut tourist spots and advised visitors not to travel to the Nilgiris for three days.

The northeast monsoon is the part of India’s annual monsoon cycle that affects Tamil Nadu mainly from October into the later months of the year. During this season, winds and weather systems bring moisture toward the state. That is why Tamil Nadu can receive substantial rain when other parts of India are leaving the main southwest monsoon period.

The article reports that the northeast monsoon remained vigorous over Tamil Nadu. Light rain fell at most places across Tamil Nadu, Puducherry and Karaikal during the preceding 24 hours. The IMD forecast heavy to very heavy rain in several districts, with isolated extremely heavy rain in Theni, Dindigul and Madurai on October 25.

This seasonal rainfall supports water supplies but can also create hazards when it becomes intense. In the Nilgiris, it triggered mudslides that killed a bus driver and blocked highways. In Krishnagiri, flash floods washed away a temporary causeway. The IMD expected the rain pattern to continue for several days, with a developing Bay of Bengal storm adding to the alert.

A developing cyclonic storm raises the risk of worsening wind and rain near the coast. Even before landfall, authorities need to monitor its track and communicate changing conditions. Coastal warnings alert ships, fishing activity, port managers and local administrations that normal operations may become unsafe.

The IMD said a cyclonic storm was likely to form over the west-central Bay of Bengal on October 26. It was expected to move toward the Andhra Pradesh coast around the morning of October 28. In response, warning signals were hoisted at nine ports, including Nagapattinam, Chennai, Cuddalore, Karaikal, Pamban and Thoothukudi.

The article does not detail specific port closures or evacuation orders. It shows that emergency planning was already active alongside the wider rain alert. Officials were dealing with blocked roads, stranded vehicles and Nilgiris rescue work, while Chennai and its suburbs remained at risk of moderate to heavy rain. Forecast updates would guide further decisions as the storm developed.