Cyclone Arnab crossed the Andhra Pradesh and Yanam coast between Bapatla and Visakhapatnam in the early hours of 28 October 2026 as a very severe cyclonic storm. The India Meteorological Department (IMD) recorded sustained winds of 125 to 135 kmph with gusts up to 150 kmph at landfall. As the first named storm of the 2026 North Indian Ocean cyclone season, it triggered heavy rain, floods and large scale evacuations across Andhra Pradesh, Odisha and nearby inland states.
What Is Cyclone Arnab and Where Did It Make Landfall?
Cyclone Arnab is a tropical cyclone that formed over the Bay of Bengal in late October 2026 and struck the east coast of India. It originated as a low pressure area over the east-central Bay of Bengal on 25 October, strengthened into a depression and then a deep depression, and was named as a cyclonic storm on 26 October. It is the first named storm of the 2026 North Indian Ocean cyclone season.
The storm moved west-northwest toward the coast and intensified into a very severe cyclonic storm before landfall. The India Meteorological Department (IMD) said the landfall process lasted from about 2 am to 8 am on 28 October 2026. The centre crossed the Andhra Pradesh and Yanam coast southwest of Yanam, between Bapatla and Visakhapatnam. Yanam is an enclave of Puducherry located within Andhra Pradesh.
At the time of crossing, Arnab packed maximum sustained winds of 125 to 135 kmph with gusts up to 150 kmph and a storm surge of about 1 to 1.5 metres above normal tide. Coastal districts such as Kakinada, Konaseema, East Godavari, Visakhapatnam and Anakapalli recorded very heavy rainfall, with some stations reporting more than 260 mm in a day.
| Stage of Cyclone Arnab | Date in October 2026 | Status |
|---|---|---|
| Low pressure area over east-central Bay of Bengal | 25 | Low pressure area |
| Depression and deep depression | 25 to 26 | Depression to deep depression |
| Named as Cyclonic Storm Arnab | 26 | Cyclonic storm |
| Intensified to very severe cyclonic storm | 27 | Very severe cyclonic storm |
| Landfall between Bapatla and Visakhapatnam | 28, 2 am to 8 am | Very severe cyclonic storm with 125 to 135 kmph winds |
| Weakened inland over north coastal Andhra Pradesh | 28 to 29 | Severe storm to deep depression to depression |
After landfall, friction with land cut off its energy supply and the system weakened step by step. By the morning of 29 October it lay as a depression over south Chhattisgarh and adjoining south Odisha and was expected to weaken further into a well marked low pressure area. Its remnants carried heavy rain inland toward southern Odisha, south Chhattisgarh, northeast Telangana, Jharkhand, West Bengal and even eastern Uttar Pradesh.
Why Cyclone Arnab Was Named Arnab
The name Arnab was contributed by Bangladesh and is pronounced Ornab. The storm received this name once its sustained winds crossed the threshold for a cyclonic storm. Names help weather agencies, media and the public identify each storm quickly and avoid confusion when more than one system is active.
In the North Indian Ocean, which covers the Bay of Bengal and the Arabian Sea, storms are named by the India Meteorological Department (IMD) in New Delhi. The IMD functions as the Regional Specialised Meteorological Centre (RSMC) New Delhi for this basin under the World Meteorological Organization (WMO) and the Economic and Social Commission for Asia and the Pacific (ESCAP) Panel on Tropical Cyclones. The panel includes 13 member countries that each contribute a set of names.
The 13 contributors are Bangladesh, India, Iran, Maldives, Myanmar, Oman, Pakistan, Qatar, Saudi Arabia, Sri Lanka, Thailand, the United Arab Emirates and Yemen. Their suggested names are placed in a common list and used in sequence. Recent examples show the order in use. Montha, suggested by Thailand, and Shakhti, suggested by Sri Lanka, were used in 2025, while Dana, suggested by Qatar, and Fengal, suggested by Saudi Arabia, were used in 2024. Arnab is the next Bangladesh name in that sequence after Nisarga and Biparjoy.
A system gets a name only after it reaches the cyclonic storm stage, when maximum sustained surface winds reach at least 34 knots or 62 kmph. Weaker stages such as low pressure area, depression and deep depression are numbered but not named. Names are chosen to be short, easy to pronounce, and neutral toward politics, religion, culture and gender.
How a Cyclone Forms Over the Sea
A tropical cyclone is an intense low pressure system that develops over warm tropical oceans with strong spiral winds, heavy rain and a calm centre called the eye. It begins as a small atmospheric disturbance and grows by drawing heat and moisture from the sea. Warm water, moist air, spin from the rotation of the Earth and calm upper winds must all be present together.
The process usually follows clear steps. A weak ripple called an easterly wave creates a patch of low pressure over the sea. Winds flow toward this patch and start to circle because the Earth rotates. This turning effect is called the Coriolis force. Air above warm water picks up heat and moisture and rises. As the moist air rises, it cools and condenses into clouds and rain. Condensation releases heat, which lowers pressure further and pulls in more air. The circle grows stronger and organises into a depression, then a deep depression, and then a cyclonic storm.
Four main conditions decide whether the seedling becomes a cyclone:
- Warm sea water of at least 26.5 degrees Celsius to a depth of about 50 metres. Warm water is the fuel. It supplies heat and vapour through evaporation.
- Plenty of moisture through a deep layer of the atmosphere, especially around 5 km height. Dry air entering the middle of the system weakens its clouds.
- An existing spin in the lower atmosphere, such as low level vorticity along a monsoon trough or an easterly wave.
- Low vertical wind shear. Wind shear is the difference in wind speed and direction between lower and upper levels. If shear is high, it tilts the cloud tower and tears the storm apart. The IMD treats shear below about 36 kmph as favourable.
This also explains why cyclones are not formed near the equator. The Coriolis force is zero at the equator and too weak within about 5 degrees latitude to start the spin. Most storms therefore form at least 500 km away from the equator.
The destructive winds come from the pressure difference between the calm low pressure eye and the surrounding high pressure air. The larger the difference, the faster air rushes inward. Friction makes the inflowing air spiral, so gusts near landfall can be much stronger than the average sustained wind. That is why Arnab showed sustained winds of 125 to 135 kmph but gusts up to 150 kmph.
Why the Bay of Bengal Produces So Many Cyclones
The Bay of Bengal produces about four cyclones for every one cyclone in the Arabian Sea. The IMD records this long term ratio as roughly 4 to 1. The Bay also hosts two cyclone seasons each year, from April to June before the monsoon and from October to December after the monsoon, with October and November as the peak.
Warm water is the first reason. The Bay stays warm through much of the year, often between 28 and 32 degrees Celsius. It is relatively shallow and enclosed on three sides, so heat builds up. Large rivers such as the Ganga, Brahmaputra, Godavari, Krishna and Irrawaddy pour huge volumes of fresh water into the Bay. This fresh water is lighter than sea water and sits on top. It forms a barrier layer that stops cooler deep water from mixing upward. The surface therefore stays warm even under a passing storm, so the storm keeps its fuel.
Moist air is the second reason. The Bay is surrounded by humid land and receives heavy monsoon rain. Its middle atmosphere stays moist, which helps thunderclouds grow tall and organise. The Arabian Sea, by contrast, receives dry air from the deserts of Oman, Yemen and the Arabian Peninsula. Dry air weakens developing clouds.
Calm upper winds form the third reason. The Bay often has low vertical wind shear during the pre-monsoon and post-monsoon windows. The Arabian Sea often has stronger shear, especially during the southwest monsoon when strong westerly winds blow. High shear breaks the vertical tower of a young storm.
Borrowed storms are the fourth reason. The Bay lies downwind of the very active Northwest Pacific. Remnants of Pacific typhoons often travel across the South China Sea and Indochina, enter the Andaman Sea and re-intensify over the warm Bay. The Arabian Sea gets no such regular inflow.
| Feature | Bay of Bengal | Arabian Sea |
|---|---|---|
| Sea surface temperature | Often 28 to 32 degrees Celsius, warm deep layer after monsoon | Cooler, strong monsoon winds mix heat downward |
| Surface salinity | Low due to river inflow, barrier layer keeps heat near surface | More saline, heat mixes easily with cooler water below |
| Moisture | High humidity, moist middle atmosphere | Dry air inflow from desert regions |
| Wind shear | Often low in April to June and October to December | Often high, especially during southwest monsoon |
| External seeds | Typhoon remnants and easterly waves from the east | Few external seeds, mostly local systems |
The season matters. During the southwest monsoon from June to September, strong winds and high shear suppress cyclone formation in both seas, though the Bay still produces monsoon depressions. When the monsoon retreats in October, winds calm down but the sea remains hot and deep warm water persists. The retreating monsoon also leaves stagnant low pressure zones. These conditions make October and November ideal for storms like Arnab.
Geography makes landfall more dangerous. The Bay has a concave, funnel like shape and a wide shallow continental shelf. Storm surge, which is the rise in sea water pushed toward the coast, piles up higher in such shallow bays. Low lying deltas of the Ganga, Godavari, Krishna and Mahanadi expose large populations in West Bengal, Odisha, Andhra Pradesh and Tamil Nadu. The 1999 Odisha super cyclone showed how deadly this combination can be.
How the IMD Classifies and Warns About Cyclones
The IMD uses sustained wind speed to place every low pressure system in one of eight categories. The measurement is the three minute average of maximum sustained surface wind. Arnab reached the sixth level, very severe cyclonic storm, with 125 to 135 kmph winds.
| IMD Category | Wind in knots | Wind in kmph |
|---|---|---|
| Low pressure area | Below 17 | Below 31 |
| Depression | 17 to 27 | 31 to 49 |
| Deep depression | 28 to 33 | 50 to 61 |
| Cyclonic storm | 34 to 47 | 62 to 88 |
| Severe cyclonic storm | 48 to 63 | 89 to 117 |
| Very severe cyclonic storm | 64 to 89 | 118 to 166 |
| Extremely severe cyclonic storm | 90 to 119 | 167 to 221 |
| Super cyclonic storm | 120 and above | 222 and above |
The IMD issues warnings in four stages as a storm approaches the coast:
- Pre-Cyclone Watch about 72 hours in advance. It warns that a cyclone may develop and asks disaster agencies to stay alert. No colour code is attached at this early stage.
- Cyclone Alert about 48 hours in advance. It gives the location and likely track and is shown in yellow. Yellow means be aware and keep watching updates.
- Cyclone Warning about 24 hours in advance. It fixes the expected place and time of landfall, wind strength and storm surge. It is shown in orange or red. Orange means be prepared for disruption. Red means take action because severe weather is expected.
- Post Landfall Outlook about 12 hours before landfall. It is shown in red and focuses on heavy rain and gale winds inland after the centre crosses the coast.
These colour codes are universal. Green means no adverse weather. Yellow means be aware. Orange means be prepared. Red means take action. During Arnab, the IMD issued red alerts for seven districts in Andhra Pradesh and later for southern Odisha districts, along with flash flood risk warnings for 13 districts of Andhra Pradesh and Yanam.
The IMD tracks storms with a network of satellites, Doppler Weather Radars, buoys, ships and computer models. Its cyclone tracker maps and bulletins give the current location, central pressure, wind speed, projected path and landfall time every few hours. The track for Arnab was updated continuously from the Andaman Sea stage to the inland depression stage over Chhattisgarh and Odisha, with radars at Visakhapatnam, Machilipatnam, Gopalpur, Raipur and Sambalpur providing close watch.
Cyclone, Hurricane, Typhoon and Tornado Compared
Cyclone, hurricane and typhoon are different names for the same type of storm, a tropical cyclone. The name changes with the ocean basin where the storm forms. Tornado and anticyclone are different phenomena.
| Term | Where It Is Used | Size and Life |
|---|---|---|
| Cyclone | North Indian Ocean, including Bay of Bengal and Arabian Sea, and South Pacific | 150 to 800 km wide, lasts days to more than a week |
| Hurricane | North Atlantic and Northeast Pacific | Same size and life as a cyclone, named hurricane in those basins |
| Typhoon | Northwest Pacific, including South China Sea and Japan | Same size and life as a cyclone, often very intense |
| Tornado | Over land, common in the United States | Narrow funnel a few hundred metres wide, lasts minutes to hours |
| Anticyclone | Any region | High pressure system with calm, sinking air, opposite of a cyclone |
The spin direction also differs by hemisphere. Storms spin counter-clockwise in the northern hemisphere and clockwise in the southern hemisphere because of the Coriolis force. Tornadoes form over land from severe thunderstorms and are far smaller but can have very high wind speeds in a narrow path. A storm surge, flooding and widespread heavy rain make tropical cyclones like Arnab more destructive over a large coastal area than a single tornado.
What Happens During and After Landfall
Landfall means the centre of the storm, or the eye, moves from the sea onto land. The landfall process for Arnab lasted about six hours. During this period the front half of the storm was already over land while the rear half was still over water. The IMD declares landfall complete only when the full centre has moved inland.
Winds are strongest near the eye wall just before and during landfall. After the centre moves inland, the storm loses its fuel because it no longer draws heat and moisture from warm sea water. Friction with land also breaks its circular flow. The system then weakens step by step from very severe cyclonic storm to severe storm, deep depression, depression and finally a well marked low pressure area.
Weakening does not mean safety. Rainfall often increases inland as the remnant pushes moisture deep into the continent. Arnab is a clear example. Andhra Pradesh reported five deaths, uprooted trees and electric poles, damaged houses and roads, and crop damage over large areas. Southern Odisha recorded extreme rain, with Patrapur in Ganjam receiving more than 540 mm and several stations in Kandhamal and Gajapati recording 370 to 460 mm. Rivers such as the Rushikulya flowed above danger level, 300 villages in Ganjam were affected and road and rail links were cut, including stretches of National Highway 16 and National Highway 326.
The response drew on lessons from the 1999 Odisha super cyclone. Andhra Pradesh shifted more than 84,000 people to relief camps before landfall and Odisha moved more than 30,000 people in the first phase, with total evacuations across the two states later crossing 1,80,000. Andhra Pradesh identified 2,199 cyclone shelters, released ₹27 crore to 20 districts, closed schools in 10 districts and deployed disaster teams. Odisha deployed 313 response teams, including nine National Disaster Response Force (NDRF) teams, 60 Odisha Disaster Rapid Action Force (ODRAF) teams and 244 Fire Services teams, and readied shelters and food stocks. The NDRF, which was raised in 2006 for disaster response, deployed 39 teams across Andhra Pradesh, Odisha, Chhattisgarh, Telangana, Puducherry and the Andaman and Nicobar Islands, with four teams airlifted as surge support. Flights were cancelled at Visakhapatnam and other Andhra airports, more than 30 trains were cancelled or diverted, and the Indian Air Force airlifted relief supplies to Vijayawada.
Key Takeaways
- Cyclone Arnab crossed the Andhra Pradesh and Yanam coast between Bapatla and Visakhapatnam from 2 am to 8 am on 28 October 2026 with sustained winds of 125 to 135 kmph.
- The name Arnab, pronounced Ornab, was contributed by Bangladesh under the WMO and ESCAP panel list for the North Indian Ocean.
- The IMD names a system only after it reaches cyclonic storm strength with winds of at least 34 knots or 62 kmph.
- Arnab was classified as a very severe cyclonic storm, which covers sustained winds of 118 to 166 kmph.
- The Bay of Bengal produces about four cyclones for every one in the Arabian Sea due to warm water, river fed barrier layer, low wind shear and typhoon remnants.
