Fresh low pressure area may turn into a cyclone for Tamil Nadu, Pg6.

Key Highlights:

• The Regional Meteorological Centre (RMC), Chennai reported a well-marked low-pressure area over the Bay of Bengal, expected to intensify into a depression and then a cyclone.
• The storm, to be named ‘Cyclone Montha’ (suggested by Thailand), is likely to form over the Southwest and adjoining Westcentral Bay of Bengal by Monday morning.
• Heavy to very heavy rainfall is forecast across Chennai, Tiruvallur, Cuddalore, Villupuram, and Chengalpattu districts.
• Orange alert has been issued for Chennai, Tiruvallur, and Ranipet districts.
• Northeast monsoon has already brought 22 cm of rainfall since October 1, roughly half the seasonal average of 44 cm.
• The Indian Coast Guard has initiated fishermen outreach and advised oil rigs and platforms to remain on alert for safety.
• The Water Resources Department has stepped up discharge from Poondi reservoir to 9,500 cubic feet per second to manage inflow.

Detailed Insights:

• Meteorological Dynamics: The low-pressure area formed due to converging moist winds over the Bay of Bengal, a typical precursor for cyclonic systems during the Northeast Monsoon period (Oct–Dec).
• Rainfall Forecast: The RMC predicts intense rainfall till the month-end, with potential flooding in low-lying areas and urban zones.
• Preparedness Measures: The Coast Guard has shepherded nearly 985 fishing boats from Tamil Nadu, Andhra Pradesh, and Puducherry to safety.
• Hydrological Management: Controlled water release from reservoirs aims to prevent urban flooding in Chennai and maintain reservoir safety.
• Monsoon Performance: The Northeast monsoon has been vigorous, contributing significantly to the state’s water reserves, particularly benefiting agricultural zones.

Scientific/Technical Concepts Involved:

• Low-Pressure Area: A region where atmospheric pressure is lower than surrounding areas, causing air to converge and rise, often leading to cloud formation and rain.
• Depression & Cyclone Formation: Successive stages of intensification — low pressure → depression → deep depression → cyclonic storm — depending on wind speed.
• Cyclone Naming: Coordinated by the Regional Specialized Meteorological Centre (RSMC), New Delhi, names are suggested by member countries of the WMO/ESCAP Panel.
• Orange Alert: Issued when heavy to very heavy rainfall (6–20 cm) is expected, urging preparedness and caution.