Bay of Bengal: Tropical Cyclone 03B tracking westward late Sept. 25; landfall forecast in far northern Andhra Pradesh, India Sept. 26 /update 2

Event

Tropical Cyclone 03B is tracking westward in the Bay of Bengal late Sept. 25. As of 20:30 IST, the storm's center of circulation was approximately 478 km (297 miles) south of Kolkata, India. Forecast models indicate the system will continue to track westward and strengthen slightly through early Sept. 26, before making landfall as a tropical cyclone in far northern Andhra Pradesh State's Srikakulam District the evening of Sept. 26. Following landfall, the system will weaken rapidly into a depression as it tracks over Andhra Pradesh and southwest Odisha before dissipating over northern Telangana late Sept. 27. The storm's track and intensity forecast remain somewhat uncertain, and the system may change accordingly over the coming days.

Government Advisories
As of late Sept. 25, Indian officials have issued red (the highest level on a four-tier scale) thunderstorms, heavy rain, and strong wind warnings for Odisha and Andhra Pradesh states from Sept. 26. Weather warnings could remain active even after the system's immediate threat has diminished, as some areas may still be highly susceptible to rain-induced hazards. The possibility of localized evacuations cannot be discounted if weather conditions prove particularly hazardous.

Hazardous Conditions
The storm may bring heavy rainfall, strong winds, and rough seas to coastal areas of northern Andhra Pradesh and southern Odisha in the coming days. Sustained heavy rainfall in parts of Odisha, Andhra Pradesh, Chhattisgarh, and Telangana could trigger flooding in low-lying communities near streams, creeks, rivers, and urban areas with inadequate stormwater drainage systems.

Sites located downstream of large reservoirs could experience flash flooding after relatively short periods of intense rainfall. Rain-induced landslides are possible in steeply sloped terrains. Flooding could isolate some communities for several days. Prolonged swells and storm surge generated by the system will likely result in coastal flooding as the system approaches land, especially in Srikakulam and Vizianagaram districts in Andhra Pradesh, as well as Ganjam district in Odisha. Persistent onshore flow could make it difficult for the surge to recede and for water levels to decrease in coastal river catchments.

Transport
Inclement weather associated with the storm could trigger localized business, transport, and utility disruptions. Floodwaters and debris flows could render some bridges or roadways impassable, impacting overland travel in and around affected areas. Areal flooding in urban locations could also result in severe traffic congestion, while strong winds will pose a hazard to high-profile vehicles. Heavy rain and low visibility may trigger flight disruptions at regional airports.

Disruptions triggered by inclement weather and resultant hazards, such as flooding, could persist well after conditions have improved. If there is severe damage to infrastructure, repair or reconstruction efforts may exacerbate residual disruptions.

Health
Stagnant pools of water during and after flooding increase the incidence of insect- and waterborne diseases, such as dengue fever, cholera, and malaria. The threat of these disease outbreaks is usually elevated in low-income or underdeveloped areas of major urban centers due to the presence of incomplete or open sewer lines. The latent threat of waterborne contaminants from inundated industrial sites cannot be discounted; exposure to raw sewage and other hazardous materials mixed with floodwaters poses a serious health threat.

Advice

Activate contingency plans in areas where officials forecast tropical storm conditions. Heed any evacuation orders that may be issued. Use extreme caution in low-lying coastal areas and near streams, creeks, and other waterways due to the potential for severe flooding and storm surge. Stockpile water, batteries, and other essentials in advance. Charge battery-powered devices when electricity is available; restrict the use of cellular phones to emergencies only. Power down mobile devices when not in use. Keep important documents and necessary medications in waterproof containers. Observe strict food and water precautions, as municipalities could issue boil-water advisories following flooding events. Take precautions against insect- and waterborne diseases in the coming weeks.

Plan accordingly for protracted commercial, transport, and logistics disruptions in areas in the path of the storm, especially if vital infrastructure is damaged. Seek updated information on road conditions before driving or routing shipments through areas where flooding has occurred. Confirm flights before checking out of hotels or driving to the airport; clearing passenger backlogs may take several days in some locations.

Resources

Joint Typhoon Warning Center
India Meteorological Department