Bay of Bengal: Tropical Cyclone Michaung tracking northwestward off the east coast of India late Dec. 4 /update 2

Tropical Cyclone Michaung is tracking northwestward in the western part of the Bay of Bengal off the east coast of India Dec. 4. As of 20:30 IST, the storm's center of circulation was approximately 1,265 km (786 miles) southwest of Kolkata, India.

Forecast models indicate that the system will strengthen briefly into a severe cyclonic storm as it tracks north-northwestward off the coast of Andhra Pradesh early Dec. 5, before weakening back into a cyclonic storm and making landfall over northeastern Andhra Pradesh State late afternoon Dec. 5. After making landfall, the storm will weaken as it tracks northward over northeastern Andhra Pradesh through early Dec. 6, before transitioning into a depression as it moves north-northeastward over eastern Telangana Dec. 6. The storm's track and intensity forecast remains somewhat uncertain, and changes may occur over the coming hours and days.

The India Meteorological Department has issued red heavy rain and strong surface wind warnings (the highest level on a three-tier scale) across coastal Andhra Pradesh Dec. 4-5, Tamil Nadu and Puducherry Union Territory Dec. 4, and Telangana Dec. 5. Red heavy rain, thunderstorm, and lightning warnings have been issued for interior Andhra Pradesh Dec. 4. Orange heavy rain and strong surface wind warnings are in place across Odisha Dec. 5. Yellow heavy rain, strong winds, thunderstorm, and lightning warnings are in place across other parts of eastern India Dec. 4-6. Officials will likely issue new alerts or update/rescind existing advisories as the storm progresses.

Disruptions are ongoing across parts of eastern India as of Dec. 4. Authorities have reported five weather-related fatalities in Chennai amid heavy flooding in parts of the city. A public holiday has been declared and schools, colleges, and offices closed in several districts of Tamil Nadu and Andhra Pradesh through at least Dec. 5. Authorities have established nearly 5,000 relief centers in affected coastal areas. All arrivals and departures have been suspended at Chennai International Airport (MAA) through at least 09:00 Dec. 5 due to the severe weather. Flights were also canceled at Tirupati Airport (TIR) Dec. 4; further flight disruptions are likely throughout parts of eastern India over the coming hours and days. Train services have been severely disrupted in Chennai and surrounding areas and several subways, metro stations, and roads are closed. Power outages have been reported in parts of Chennai.

Sustained heavy rainfall could trigger flooding in low-lying areas and those with easily overwhelmed drainage systems. Localized evacuations, flash flooding, and landslides are possible if weather conditions prove hazardous.

The inclement weather could trigger localized business, transport, and utility disruptions, rendering some bridges or roadways impassable. Flight disruptions at regional airports and temporary closures of ports are also possible. Stagnant pools of water during and after flooding increase insect- and waterborne diseases, such as dengue fever, cholera, and malaria. Raw sewage and other hazardous materials mixed with floodwaters pose a serious health threat.