IMD Issues Fresh Depression Alert Over South Andaman Sea As Cyclone Arnab Remnants Impact Chhattisgarh, MP and UP

Barely two days after severe cyclone Arnab made landfall, weather activity has resumed over the Bay of Bengal. The India Meteorological Department (IMD) reported the formation of a fresh low-pressure area over the South Andaman Sea, which is projected to intensify into a depression over the next two days.

The new system is developing while Arnab's remnants continue to affect central and eastern parts of India. On Thursday morning, the remnant circulation lay as a depression over south Chhattisgarh and adjoining south Odisha, centered approximately 20 km west of Jagdalpur.

During the 12-hour period leading up to 5:30 am on Thursday, regions including Odisha, coastal Andhra Pradesh, and Yanam recorded heavy to very heavy rainfall. Stations such as Gopalpur and Machilipatnam registered 9 cm of rain each, while Balasore, Paradip Port, Tuni, and Amaravati recorded 7 cm each. Keonjhar and Visakhapatnam received 6 cm each, and Jharsuguda recorded 5 cm.

The IMD forecast isolated very heavy rainfall over East Uttar Pradesh on Thursday, alongside similar conditions expected over East Madhya Pradesh and Chhattisgarh. East Uttar Pradesh may continue to see isolated heavy rainfall on Friday. Meanwhile, the remnant depression from Arnab is anticipated to track nearly northwards and weaken into a well-marked low-pressure area by Thursday evening.

Despite the churning winds and torrential rains of cyclone Arnab typically lowering sea-surface temperatures (SSTs), satellite imagery indicated remarkably warm waters. Sea-surface temperatures reached around 30°C near the Andaman and Nicobar Islands and the adjoining east-central Bay, with much of the rest of the Bay maintaining temperatures around 29°C. These warm waters provide a favorable source of energy for the fledgling system.

The IMD notes that the new low-pressure area could become well-marked over the South Andaman Sea on Friday. Moving west-northwest towards the north Tamil Nadu-Andhra Pradesh coast, it is likely to intensify into a depression over the south-east Bay and adjoining parts of the Andaman and Nicobar Islands and the Andaman Sea by Saturday.

Broader atmospheric signals are also supporting this activity. A positive Indian Ocean Dipole (+IOD) has emerged alongside an active Madden-Julian Oscillation (MJO) signal propagating across the basin. Enhanced upper-atmosphere easterly winds are also influencing the evolution of these weather systems.

Further afield in the north-west Pacific, super typhoon In-Fa is tracking across the open Pacific, roughly following the path of predecessor super typhoon Champi. Located about 3,500 km east of the Philippines, its eventual track remains under observation to determine if it will send incoming pulses into the Bay of Bengal.

"Frequent back-to-back weather systems and heavy rainfall across major agricultural and industrial corridors can create localized supply chain disruptions, impact logistics, and affect regional economic activity. Businesses operating in logistics, supply chain management, and agriculture must factor meteorological updates into their operational planning and risk mitigation strategies to navigate potential infrastructural delays efficiently." — Dr. Shishir Gupta, Founder & CEO, StartupLanes