Cyclone Ditwah in the Southwest Bay of Bengal and Cyclone Senyar in the eastern Indian Ocean formed within just a few days of each other. Their timing is not random. It tells us how quickly the region is heating and how India’s climate risk is shifting in real time. When two named cyclones appear almost at the same time in the northern Indian Ocean, it naturally draws attention. But what makes this pair alarming is not just their timing, but their geography.
While Senyar emerged from the far eastern edge near the Strait of Malacca, Ditwah developed in the traditional cyclone nursery near Sri Lanka. They did not follow the familiar singular "Super Cyclone" pattern. Instead, they revealed how dramatically the Indian Ocean is changing underneath us.
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Both the Bay of Bengal and the eastern Indian Ocean are warming so fast that the water now behaves like an overheated engine, capable of generating and sustaining multiple storm systems simultaneously. That shift has serious consequences for India’s rainfall patterns, coastal flooding, fishing activity, shipping routes, and the stability of the monsoon.
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"The ocean is no longer behaving like two separate regions; it is behaving like one large, overheated engine."
A Rare Formation in the East Senyar was an unusual storm from the beginning. It formed in late November over the Strait of Malacca a region that rarely sees cyclones due to its proximity to the equator. With winds reaching cyclonic strength, it influenced moisture movement across the Andaman Sea before weakening. Its formation so far east signals that the "danger zone" for cyclogenesis is expanding, potentially giving storms more time to gather strength before reaching land.
The Bay’s Boiling Point Almost simultaneously, Cyclone Ditwah developed near the Sri Lanka coast in an unusually warm Southwest Bay of Bengal. Moving toward the Tamil Nadu–Andhra region, it brought heavy rainfall and rough seas. Even though the two systems formed in distinct parts of the eastern basin, both were fuelled by the same heat pattern spreading across the Indo-Pacific. This is not a coincidence; this is how a fast-warming ocean behaves.
The Science of the Surge Scientists have been warning about this trend for years. The Indian Ocean is now the fastest-warming tropical ocean on Earth, heating at about 0.12 degrees Celsius per decade since 1950. Sea surface temperatures in the Bay of Bengal have risen significantly in the last four decades. Overall, the Indian Ocean has warmed by 1.5 degrees Celsius since pre-industrial times, faster than the global average.
During Cyclone Remal in 2024, some pockets of the Bay touched 32 to 33 degrees Celsius nearly four degrees above normal. Cyclones usually require water temperatures of 27 to 28 degrees Celsius to form. Today, the Bay and parts of the Arabian Sea often stay above 30 degrees Celsius for long stretches. This makes it easier for storms to form, faster for them to intensify, and more likely that they will dump massive amounts of rain.
By The Numbers: The Indian Ocean's Fever Chart
- 33°C: Peak water temperatures recorded in the Bay of Bengal during recent storms (approx. 4°C above normal).
- 0.12°C: The rate of warming per decade in the Indian Ocean since 1950; the fastest of any tropical ocean on Earth.
- 150%: The increase in severe cyclonic storms in the Arabian Sea since 1980, adding to the Bay's existing volatility.
- 170 million: The number of Indians living in coastal districts who are now on the frontlines of this shift.
A Population on the Frontline This rising risk is not only about meteorology; it is about people. About 15 percent of India’s population over 170 million people lives in coastal districts. More than three-fourths of the coastline is exposed to cyclone-related hazards, and over 80 percent of Indians live in districts highly vulnerable to extreme rainfall. This means even a "moderate" storm can be dangerous if it slows down, interacts with another weather system, or arrives when rivers are already full.
Cyclone Montha in October 2025 proved this clearly. It was not a massive cyclone, yet tens of thousands had to be evacuated in Andhra Pradesh because the soil and rivers were already saturated. Senyar and Ditwah formed in a similar environment where each system heightens the damage potential of the next.
The Dual-Basin Threat While Ditwah and Senyar both formed in the eastern sector; they highlight a broader "dual-basin" volatility. The Bay has always been active, but the Arabian Sea, once relatively quiet is catching up. Research shows that the frequency of very severe cyclonic storms in the Arabian Sea has more than doubled since 1980. The ocean is no longer behaving like two separate regions; it is behaving like one large, overheated system where storms can pop up anywhere, from the Strait of Malacca to the Arabian Sea coast.
The New Normal This is why the Ditwah–Senyar pair matters. The geography of storm formation has expanded. Warm waters are spreading farther east toward Indonesia and farther south toward the equator, extending the cyclone season. Back-to-back cyclones are becoming more common. Recent years have seen a chain of storms; Fani, Amphan, Gulab, Jawad, Dana, Montha, Ditwah all linked to rising sea temperatures. The compounding effect is increasing: Senyar stirred the atmosphere and disturbed moisture patterns, creating an unsettled system that Ditwah then entered.
India’s future risk is no longer about one big cyclone a year. It is about more frequent formations, rapid intensification events, and inland districts facing flood threats they were never exposed to earlier. One study has shown that for a cyclone the size of Amphan, the number of people exposed to storm-surge flooding in the Bay of Bengal could triple by 2100 due to sea level rise alone.
The Human Cost At the heart of it, the story is human. The real danger is not just wind speed; it is how fast informal settlements flood, how much seawater reaches farms, how often fishing communities lose days of work, and how quickly cities like Chennai or Visakhapatnam get overwhelmed. It is also about how effectively warnings reach people and how quickly evacuations can happen.
Ditwah and Senyar are reminders that every storm tests our forecasting systems, communication networks, and the safety nets that protect millions. These storms are not rare; they are previews. The Indian Ocean is warming, sea levels are rising, and the atmosphere is holding more moisture.
Cyclone Ditwah and Cyclone Senyar forming within days of each other is not an accidental pairing. It is the ocean sending a clear signal. For India’s 170 million coastal residents, this is not just a weather update. It is a warning about the climate era we have already entered. We are no longer waiting for climate change to arrive on our shores; with Ditwah and Senyar, it has already made landfall.