Cyclone Arnab is the name given to a developing weather system over the Bay of Bengal that India's weather agency is tracking closely as it moves towards the east coast. According to the India Meteorological Department (IMD), a well-marked low-pressure area over the east-central Bay of Bengal is likely to become a depression on 25 October and then strengthen into a cyclonic storm by the morning of 26 October. The system is forecast to move west-northwest towards the coast near north Andhra Pradesh and south Odisha, with a possible approach to the coast on the morning of 28 October. Some outlets have reported a landfall on the afternoon or night of 28 October, but that timing should be treated as a forecast reported in coverage, not as a confirmed event, because the system's exact track and intensity can still change.

Background: how Cyclone Arnab forms over the Bay of Bengal

Tropical cyclones in the Bay of Bengal typically form when warm sea-surface temperatures, moist air and favourable upper-level winds allow a low-pressure area to organise and strengthen. The process usually follows a sequence: a low-pressure area becomes a well-marked low, then a depression, then a deep depression, and then a cyclonic storm once sustained wind speeds reach a defined threshold and a clear circulation has formed. Naming follows a regional system in which countries around the North Indian Ocean contribute names in turn; Arnab is the name assigned to this system under that arrangement. The name itself does not indicate severity — severity is described by the IMD's classification and by forecast wind speeds, rainfall and storm surge, not by the name alone.

The Bay of Bengal is one of the world's most cyclone-prone basins, and its geography makes coastal states particularly vulnerable. The coastline of Odisha and Andhra Pradesh is low-lying in places, densely populated in coastal districts, and exposed to both heavy rainfall and sea-water inundation when a cyclone approaches. Historical experience in the region has shaped a strong emphasis on early warnings, evacuation planning and community preparedness, because timely action before landfall can substantially reduce loss of life even when property damage remains significant. That is why IMD bulletins, state disaster management instructions and local administration messages should be followed closely as a system develops, rather than relying on a single forecast issued days in advance.

The current system is being monitored by IMD Director General Mrutyunjay Mohapatra's organisation, which issues regular bulletins updating the system's position, movement and expected intensity. Those bulletins are the authoritative source for the system's status, and they are updated as new observations from satellites, buoys, ships and coastal stations become available. Because a cyclone's path can shift, especially several days before landfall, forecasts are often presented with a cone of uncertainty showing the range of possible tracks. Residents and travellers in potentially affected areas should therefore check the latest bulletin rather than relying on an earlier forecast that may have been superseded.

Cyclone Arnab: forecast track and rainfall outlook

Under the forecast supplied for this article, the well-marked low over the east-central Bay of Bengal is likely to concentrate into a depression on 25 October and into a cyclonic storm by the morning of 26 October. It is then forecast to move west-northwest towards the coast near north Andhra Pradesh and south Odisha, approaching the coast on the morning of 28 October. Some outlets have reported landfall in the afternoon or night of 28 October; that is presented here as a reported forecast, not as a confirmed landfall, and readers should await IMD confirmation for the actual landfall time and place. The distinction matters: a forecast landfall window helps authorities prepare, but only observations at the time can confirm when and where a system actually crosses the coast.

Rainfall is expected to be the most widespread impact, even for areas that do not experience the strongest winds. Heavy to very heavy rainfall is forecast for coastal Odisha on 27 October, and for north Andhra Pradesh and Odisha on 28 October, with extremely heavy rainfall — more than 20 centimetres in 24 hours — possible in some places on 28 October. Isolated heavy rainfall is also forecast for West Bengal on 28 October, and for Chhattisgarh, Jharkhand and Bihar, isolated heavy rainfall is forecast on 28-29 October as the system moves inland and weakens. Extremely heavy rainfall can cause local flooding, waterlogging in urban areas, disruption to road and rail transport, and rises in rivers and streams, even well away from the coast, so inland districts should not assume they are unaffected simply because they are not on the shoreline.

Wind and sea conditions are the other major concern. As a system strengthens into a cyclonic storm, wind speeds rise and sea conditions become rough to very rough. Fishermen have been advised not to venture into the east-central and southeast Bay of Bengal until 25 October, and then not into the west-central and northwest Bay of Bengal from 26 to 29 October, under the advisory supplied. That phased advice reflects the system's expected movement: the danger zone shifts westward as the storm moves towards the coast. People living in coastal areas, those with boats or fishing equipment to secure, and travellers planning journeys through the affected region should follow state and district instructions, keep emergency supplies ready, and avoid unnecessary travel during the period of heaviest weather.

Why Cyclone Arnab matters for coastal and inland communities

Cyclones matter because they combine several hazards at once: strong winds that can damage homes, trees and power lines; heavy rainfall that can flood low-lying areas; storm surge, where sea water is pushed ashore; and disruption to transport, power, water supply and communications. For coastal communities in Odisha and Andhra Pradesh, the immediate priorities are safety, shelter and information: knowing whether an evacuation order applies, where shelters are located, and how to stay in contact with family if mobile networks are disrupted. For farmers, the timing of heavy rain can affect standing crops and harvested produce, and for fishing communities, days at sea lost to advisories represent lost income even when no damage occurs.

Inland areas also face real risks, which is why the forecast extends to Chhattisgarh, Jharkhand, Bihar and West Bengal. As a cyclone weakens over land, it can still produce intense rainfall bands, gusty winds and local flooding. Urban areas with poor drainage can experience waterlogging after extremely heavy rain, while rural areas may see damage to roads and disruption to essential services. The lesson from past Bay of Bengal systems is that preparedness should not stop at the coastline: district administrations inland need to monitor rainfall, river levels and local advisories, and residents should avoid crossing flooded roads or venturing near swollen water bodies during and after the heaviest rain.

There is also a wider significance in how such systems are communicated. Clear, updated warnings save lives, but they depend on people receiving and acting on them. Rumours on social media about landfall times, wind speeds or affected districts can spread faster than official updates, and they can cause either panic or complacency. The safest approach is to rely on IMD bulletins and on instructions from state disaster management authorities and district administrations, and to treat any single social media post — however confident it sounds — as unverified until it matches an official update. That discipline is especially important when a landfall time is being reported in some outlets before it has been confirmed.

Key facts: Cyclone Arnab forecast

  • System: Well-marked low over the east-central Bay of Bengal, per IMD.
  • Development: Likely depression on 25 October; likely cyclonic storm by the morning of 26 October.
  • Movement: West-northwest towards the coast near north Andhra Pradesh and south Odisha; possible coastal approach on the morning of 28 October.
  • Landfall: Reported in some outlets as afternoon or night of 28 October — presented here as a forecast, not confirmed.
  • Rainfall: Heavy to very heavy rain in coastal Odisha on 27 October and in north Andhra Pradesh and Odisha on 28 October; extremely heavy rain over 20 cm in 24 hours possible in places on 28 October; isolated heavy rain in West Bengal on 28 October and in Chhattisgarh, Jharkhand and Bihar on 28-29 October.
  • Fishermen advisory: Do not venture into the east-central and southeast Bay of Bengal until 25 October; then avoid the west-central and northwest Bay of Bengal from 26 to 29 October.
  • Monitoring authority: IMD, led by Director General Mrutyunjay Mohapatra.

For context on other recent severe weather in the region, see coverage of Super Typhoon Champi. Readers interested in preparedness and seasonal conditions may also find the Mauritius cyclone season weather guide useful for general cyclone-season information.

What happens next with Cyclone Arnab

Over the next few days, IMD bulletins will update the system's position, intensity and expected track, and state governments will issue more specific instructions for districts in the forecast path. Those instructions may include evacuation of low-lying coastal areas, closure of schools or offices in affected districts, suspension of fishing and port activities, and deployment of disaster response teams, power restoration crews and medical support. Travellers should check the status of trains, flights and road routes before travelling through Odisha, Andhra Pradesh, West Bengal, Chhattisgarh, Jharkhand or Bihar on 27-29 October, and should postpone non-essential travel if advisories recommend it.

After the system crosses the coast and weakens, attention will turn to rainfall, flooding and recovery: restoring power and communications, clearing roads, assessing damage to homes, crops and infrastructure, and providing relief where needed. The actual impact will depend on the system's final intensity at landfall, the exact point where it crosses the coast, and how much rain falls over already saturated ground. Until then, the most useful action for anyone in the forecast area is simple and practical: follow the latest official bulletin, prepare for heavy rain and possible disruption, secure property and boats where advised, and avoid spreading unconfirmed landfall claims. Cyclone Arnab is still a developing forecast, and its story will be written by observations over the next three days, not by any single early report.