Volkswacht Bodensee - Bay cyclone forecast to strike Andhra-Yanam coast at very severe strength

A developing cyclone over the Bay of Bengal is forecast to intensify into a very severe cyclonic storm and bring dangerous weather to parts of southern India, including extremely heavy rain and destructive seas.

Isolated rainfall above 20 centimetres is forecast over Tamil Nadu, Puducherry and Karaikal, and Kerala and Mahe. Coastal Andhra Pradesh and Yanam may receive isolated extremely heavy rain on Tuesday and Wednesday, with similar conditions forecast for Telangana on Wednesday.

Heavy to very heavy rain of 7-11 cm is expected at isolated locations in Tamil Nadu, Puducherry and Karaikal, Kerala and Mahe, and South Interior Karnataka. Heavy rain is also forecast at isolated places in Rayalaseema and Coastal Karnataka.

The largest threat is along the Andhra Pradesh coast, where landfall is expected by Wednesday. Squalls, gale-force winds and rough to very rough seas are forecast over the western and central Bay from Tuesday, with effects extending to Andhra Pradesh and the neighbouring Odisha coast.

By Sunday morning, the parent depression had strengthened into a deep depression. It was centred about 420 km north-northwest of Sri Vijaya Puram, 870 km east-southeast of Visakhapatnam, 960 km east-southeast of Kakinada, 1,060 km east-southeast of Machilipatnam and 1,130 km east of Bapatla.

The system was forecast to move nearly southwest and strengthen into a cyclonic storm over the east-central and adjoining southeast Bay early on Sunday. It was then expected to turn west-northwest and become a severe cyclone over the west-central Bay by Tuesday morning.

The India Meteorological Department expected a subsequent northwestward track and further intensification. The storm was forecast to reach the west-central Bay near Andhra Pradesh on Wednesday morning and cross the Andhra Pradesh-Yanam coast between Bapatla and Visakhapatnam around Tuesday midnight or Wednesday morning.

At landfall, maximum sustained winds were projected at 115-125 km/h, with gusts up to 140 km/h. IMD warned fishers and other mariners of increasingly dangerous conditions across the Bay.

Wave heights over the west-central Bay were expected to reach 13-20 feet from Sunday evening, rising to 20-30 feet from Monday morning and 23-32 feet by Tuesday. Conditions could become phenomenal on Wednesday, with waves above 46 feet until the afternoon before gradually easing.

Slow movement across exceptionally warm water may allow the system to draw energy and moisture for longer. Sea-surface temperatures along the projected track are about 30°C and only slightly lower near the Andhra Pradesh coast. The US Joint Typhoon Warning Center said atmospheric and ocean conditions were favourable for rapid intensification.

A moisture-bearing trough across north coastal Tamil Nadu, connected to a low-pressure area over the southeast Arabian Sea and nearby Lakshadweep, could provide an additional supply of moisture. The combined systems may produce strong surface winds across North and South Interior Karnataka, Coastal Andhra Pradesh and Yanam, and Rayalaseema over three to four days.

The storm’s exact track and pace of strengthening will determine the eventual landfall impacts. On Sunday afternoon, Google DeepMind lowered from 100% to 97% its estimated probability that the cyclone would reach extremely severe strength, with projected peak sustained winds of 200 km/h before landfall.

M.Schneider--VB