The India Meteorological Department (IMD) has not forecast a cyclonic storm over the Bay of Bengal, despite references to “Cyclone Arnab” on social media and in some weather reports. The developing system is forecast to strengthen into a depression and then a deep depression while moving west-northwest towards the north Andhra Pradesh and south Odisha coast. Coastal Andhra Pradesh faces the strongest rainfall threat on September 23 and 24, with rain intensifying over Telangana from September 24 as the system moves inland.
The latest reported IMD track places the coastal crossing in the Visakhapatnam-Gopalpur sector during the night of September 23 or early September 24. IMD has warned of very heavy rain over Coastal Andhra Pradesh and Yanam on September 22 and isolated extremely heavy rain on September 23 and 24. Telangana is forecast to receive isolated very heavy rainfall from September 23 to 25.
Why the system is not officially Cyclone Arnab
Arnab is a name submitted by Bangladesh and included in the official WMO/ESCAP list of tropical cyclone names for the North Indian Ocean. RSMC New Delhi assigns a name only after a weather system reaches cyclonic-storm intensity.
IMD officials have said the current Bay of Bengal system is forecast to strengthen into a deep depression but not into a cyclonic storm. Arnab has therefore not been officially assigned to the system.
The absence of a cyclone designation does not remove the weather threat. A deep depression can produce extremely heavy rainfall, strong winds, rough seas, local flooding and transport disruption, especially near its track and after landfall.
Andhra Pradesh districts facing the highest rain risk
The strongest Andhra Pradesh warning is concentrated along the coast. Kakinada, Dr B.R. Ambedkar Konaseema, East Godavari, West Godavari, Eluru and Krishna face the highest rainfall concern on September 23 and 24, with isolated extremely heavy rain forecast.
Heavy to very heavy rainfall is also forecast in Srikakulam, Parvathipuram Manyam, Vizianagaram, Visakhapatnam, Anakapalle, Alluri Sitharama Raju and NTR districts on September 23. Palnadu, Guntur, Bapatla, Prakasam and Nellore are also under a heavy-rain threat as the rain belt spreads across coastal Andhra Pradesh.
Separate Andhra Pradesh disaster-management guidance points to significant rainfall over Alluri Sitharama Raju, Visakhapatnam, Eluru, NTR and Krishna districts. Moderate to heavy rain is forecast to continue across coastal districts on Thursday and Friday. Parts of Prakasam, Nellore, Kurnool and Nandyal are also forecast to receive moderate rainfall as the system moves inland.
IMD's broader subdivision warning places Coastal Andhra Pradesh and Yanam under a very-heavy-rain warning on September 22 and an extremely-heavy-rain warning on September 23 and 24, followed by a heavy-rain warning on September 25. Rayalaseema is forecast to experience thunderstorms, lightning and strong surface winds during much of this period, while the most intense rainfall remains concentrated over the coastal districts.
Telangana risk rises after the system moves inland
The stronger rainfall phase in Telangana is forecast after the system crosses the coast. September 24 and 25 are the main impact days, with eastern districts closest to the system's inland track facing the greatest rainfall threat.
Jayashankar Bhupalpally, Mulugu and Bhadradri Kothagudem are among the districts forecast to receive the heaviest rain. Isolated locations are forecast to approach 200 mm during the two-day period. Komaram Bheem Asifabad, Mancherial, Jagtial, Peddapalli, Karimnagar, Rajanna Sircilla, Hanamkonda, Warangal, Jangaon, Mahabubabad, Khammam and Suryapet are forecast to receive moderate to heavy rainfall.
Other parts of Telangana are forecast to receive lighter to moderate rain. Hyderabad is not in the highest-risk group, but the city is forecast to receive spells of moderate rainfall during September 24 and 25, with some locations around 20-40 mm. Intense short-duration showers can still cause local water accumulation and traffic delays in vulnerable areas.
IMD's national outlook calls for fairly widespread to widespread rainfall over Telangana through September 26, with isolated very heavy rainfall from September 23 to 25 and thundersqualls as the system moves inland.
Strong winds, rough seas and local flooding remain concerns
The coastal threat extends beyond rainfall. IMD has forecast winds over the west-central and adjoining northwest Bay of Bengal at 55-65 kmph, gusting to 75 kmph during the peak phase. Rough to very rough sea conditions are forecast along and off the north Andhra Pradesh, Odisha and West Bengal coasts. Fishermen have been advised to stay out of affected waters during the warning period.
IMD impact guidance warns that very heavy rain and strong winds can cause waterlogging and inundation in low-lying areas, local flooding, damage to weak structures and crops, fallen branches and disruption to road or rail movement. Residents in districts under orange or red warnings should follow updated district advisories because the zone of heaviest rain can shift as the system approaches the coast and moves inland.