The India Meteorological Department (IMD) has raised a pre-cyclone alert for the coasts of Andhra Pradesh and neighboring south Odisha, indicating that a depression in the Bay of Bengal is expected to develop into a very severe cyclonic storm before it strikes the Andhra coast on October 28.
In a special tropical weather outlook released on Sunday, the IMD reported that the system was located over the east-central and adjacent southeast Bay of Bengal at 5:30 AM IST, approximately 440 kilometers north-northwest of Sri Vijaya Puram in the Andaman and Nicobar Islands, and 980 kilometers east-southeast of Visakhapatnam and Kakinada in Andhra Pradesh.
According to Manorama Mohanty, the director of IMD Bhubaneswar, Cyclone Arnab is projected to hit between Bapatla and Visakhapatnam with wind speeds ranging from 115 to 125 km/h on October 28, and gusts potentially reaching up to 140 km/h.
The depression has been moving southeast at about 5 km/h over the six hours prior to the announcement. The IMD anticipates that the system will first move southward and evolve into a deep depression by Sunday before shifting west-northwest. It is forecasted to become a cyclonic storm by early October 26 and develop into a severe cyclonic storm by early October 27, continuing to strengthen as it nears the Andhra coast.
The storm is expected to make landfall between Bapatla and Visakhapatnam around 11:30 AM IST on October 28, with maximum sustained winds anticipated to reach 115 to 125 km/h, accompanied by gusts of up to 140 km/h. Following landfall, the storm is predicted to weaken, with wind speeds declining to between 85 and 95 km/h and gusts up to 105 km/h by the afternoon of October 28.
Warm sea temperatures are likely to enhance the storm’s intensity, with surface temperatures in the east-central and adjacent west-central Bay of Bengal currently around 30 degrees Celsius, while parts of India’s east coast hover around 29 degrees Celsius. The combination of warm waters and favorable atmospheric conditions could facilitate further intensification of the system.
The ocean heat content in much of the Bay of Bengal is estimated at 80 to 100 kilojoules per square centimeter, with some areas reaching 100 to 120 kilojoules per square centimeter. The bulletin also mentioned increased low-level vorticity and moderate wind shear as contributing factors to the storm’s development.
The Madden-Julian Oscillation, a weather pattern that affects tropical rainfall and storm formation, is expected to remain in a favorable phase during this forecast period, potentially aiding further storm development in the Bay of Bengal. However, the IMD noted varying predictions among weather models concerning the storm’s final strength, with estimates of peak intensity ranging from 50 to 70 knots.
While the IMD has high confidence in the current position and intensity of the system, it maintains moderate to high confidence in the forecast track and intensity. Some models suggest that the system may move northward after landfall, although its path and strength will be updated as more information becomes available.
Residents along the eastern coastline have been urged to stay updated with official weather reports regarding the storm’s movement, intensity, and potential impact.
