Shrayan Sen
The India Meteorological Department (IMD) has confirmed that Cyclone Ditwah, currently over the southwest Bay of Bengal, will not make direct landfall along the Tamil Nadu coastline. Instead, it will skirt past Chennai while advancing northwards over the sea.
Chennai to Be Affected by Outer Rain Bands
Although Chennai will not face the full brunt of the cyclone, its outer spiral bands are expected to bring intermittent heavy rain, especially during the evenings and early mornings. Wind speeds may increase significantly, with gusts occasionally surpassing 80–90 km/h along open coastal stretches. Residents may witness sudden bursts of intense rainfall followed by short dry intervals, typical of cyclones that pass parallel to shorelines.
Infrastructure effects may include temporary power outages due to treefalls and short circuiting, delays in bus and metro services because of flooded stretches, and blockages from fallen tree branches. Coastal neighbourhoods such as Marina, Besant Nagar, and Ennore may be subjected to high swells and wave overtopping, prompting increased surveillance by disaster-management teams.
Northward Progress and Storm Evolution
Current projections suggest that Ditwah will continue travelling in a north-northwesterly direction, keeping a safe offshore distance from Tamil Nadu before moving closer to the Andhra coast. The system is expected to maintain cyclone-strength intensity for at least 36–48 hours before beginning to weaken due to cooler waters further north and increasing wind shear.
Meteorologists note that the exact trajectory could still shift subtly. If it drifts marginally closer, the impact on the Tamil Nadu coast could intensify; if it moves a little farther out, the rainfall may be more moderate. Regardless, direct landfall currently remains a low probability scenario.
Weather Effect on West Bengal
Although the cyclone will pass hundreds of kilometres south of West Bengal, its broad cloud shield will extend across the Bay of Bengal into the eastern Indian plains. On December 2, South Bengal is expected to observe a widespread layer of mid-level clouds, giving the sky a greyish-white appearance throughout the day.
Coastal pockets such as Digha, Mandarmani and Sundarbans may experience light drizzle or mist-like precipitation due to moisture-filled winds arriving from the sea. Inland regions—including Kolkata—are more likely to receive overcast skies with daytime dimness but minimal rainfall activity. The overcast conditions will also suppress daytime sunshine, resulting in slightly hazy, humid, and warmer weather compared to the crisp winter conditions recently observed.
Temporary Rise in Temperatures
The cloud cover induced by Ditwah is expected to significantly influence nighttime temperatures in West Bengal. Normally, under clear winter skies, the earth rapidly loses heat at night, causing temperatures to drop. However, the clouds will act like a thermal blanket, trapping warmth and inhibiting radiational cooling.
As a result, minimum temperatures across South Bengal may rise by 2–3°C, making early mornings noticeably less chilly. The shift may be particularly felt in areas like Kolkata, Kalyani, Burdwan, and the 24 Parganas. Maximum temperatures may remain steady or fall slightly due to reduced sunlight, but the nights will feel warmer and moderately humid.
Advisory & Precautions
- For Tamil Nadu: Residents should secure lightweight outdoor objects and avoid standing near tall trees during high-wind periods. Travel during peak rainfall hours should be minimized unless necessary.
- For coastal fishing sectors: Authorities reiterate a complete halt to ocean-based fishing and trawling operations until the sea states stabilise.
- For West Bengal: Those expecting the arrival of winter’s deeper cold should anticipate a brief pause. The cloudy conditions and mild drizzle may also slow down fog formation temporarily.
- General recommendation: Monitor weather bulletins issued by IMD and state agencies, avoid misinformation and follow guidance from municipal and disaster-management bodies.
In conclusion, Cyclone Ditwah’s direct threat remains offshore for Tamil Nadu, particularly Chennai, but its broader atmospheric influence reaches far beyond — altering weather patterns as distant as West Bengal. Chennai will see wind and rain effects without landfall, while Bengal experiences cloud-linked warmth and coastal drizzle, marking a subtle yet notable interruption to the onset of winter.