Twin Low-Pressure Systems Brewing Over Seas
Two active low-pressure systems—one over the southeast Arabian Sea and another over the southwest Bay of Bengal—are set to trigger heavy to extremely heavy rainfall across large parts of southern India over the next few days.
Twin Low-Pressure Systems Brewing Over Seas
Heavy to extremely heavy rainfall across large parts of southern India
CNB World Times
New Delhi, October 21, 2025 — The India Meteorological Department (IMD) on Tuesday said that two active low-pressure systems—one over the southeast Arabian Sea and another over the southwest Bay of Bengal—are set to trigger heavy to extremely heavy rainfall across large parts of southern India over the next few days.
According to the IMD, the well-marked low-pressure area over the southeast Arabian Sea persisted in the same region as of Tuesday morning and is likely to move slowly westwards, intensifying into a depression within 24 hours.
Meanwhile, under the influence of an upper air cyclonic circulation, another well-marked low-pressure area formed over the southwest Bay of Bengal early on Tuesday. The system is expected to move west-northwestwards and strengthen into a depression by Wednesday afternoon (October 22) over the southwest and adjoining west-central Bay of Bengal, off the north Tamil Nadu and south Andhra Pradesh coasts. It is likely to intensify further as it moves inland over the next 24 hours.
An upper air cyclonic circulation also persists over the south Andaman Sea, while a Western Disturbance is active across northern India, influencing the broader weather pattern.
Heavy Rains Forecast for South India
The IMD has forecast widespread light to moderate rainfall, accompanied by heavy to very heavy rainfall in several parts of Tamil Nadu, Kerala, Andhra Pradesh, Karnataka, and Telangana through the week.
Tamil Nadu and Puducherry are expected to experience extremely heavy rainfall (≥21 cm) on October 21 and 22, while Kerala could see similar intensity on October 22.
Coastal Andhra Pradesh and Rayalaseema are likely to receive very heavy rainfall between October 21 and 23.
South Interior Karnataka may witness heavy spells on October 21 and 22, and North Interior Karnataka on October 23 and 24.
Thunderstorms with lightning are likely across most parts of the southern peninsula over the next five days.
Rainfall Expected in East, Central, and Northern Regions
Andaman & Nicobar Islands will continue to receive moderate to heavy rain till October 27, while Odisha may witness isolated heavy rainfall on October 25 and 26.
Thunderstorms with gusty winds (30–50 km/h) are likely over Odisha, Madhya Pradesh, Vidarbha, and Chhattisgarh till October 25.
In the north, Uttarakhand and Himachal Pradesh may experience thunderstorms with lightning on October 21 and 22.
Marine Warnings Issued for Fishermen
The IMD has issued strong warnings for both the Arabian Sea and the Bay of Bengal regions.
Arabian Sea:
Squally winds reaching 35–55 km/h are likely along and off Kerala, Karnataka, and South Tamil Nadu coasts, and over the Lakshadweep and Comorin areas till October 24.
Wind speeds may increase to 60 km/h over parts of the south and central Arabian Sea between October 21 and 23.
Sea conditions will remain rough to very rough, posing risks for marine activities.
Bay of Bengal:
Winds are likely to reach 50–70 km/h over the southwest and adjoining west-central Bay of Bengal from October 22 to 24.
Coastal Tamil Nadu and south Andhra Pradesh may experience squally weather with winds up to 70 km/h on October 23 and 24.
Sea conditions are expected to remain rough to very rough till October 24.
Fishermen Advisory:
Fishermen have been advised not to venture into the Arabian Sea till October 23 and the Bay of Bengal till October 24. Those already out at sea are urged to return to shore immediately.
IMD’s Outlook
The IMD has warned that the twin low-pressure systems could lead to localized flooding, waterlogging, and disruption of transport in vulnerable areas of Tamil Nadu, Kerala, coastal Andhra Pradesh, and Karnataka. Authorities have been urged to remain on alert and ensure adequate preparedness in coastal and low-lying districts.
With two simultaneous systems developing on both sides of the peninsula, southern India is set for an active and wet spell through the week, the weather department added.
What's Your Reaction?
