Depression Looms Over Bay of Bengal – Widespread Heavy Rain Expected Across South and West India!
Good Morning! Today, September 25, 2025, we dive into the latest weather estimates as back-to-back systems continue to influence the subcontinent.
While Typhoon Rakasa (தைபூன் ரகசா) has begun to weaken over the South China Sea, attention is quickly shifting back to the Bay of Bengal, where a potent new system is forming.
The Return of the Low-Pressure System
The previous low-pressure area near Odisha has weakened into an Upper Air Cyclonic Circulation (UACC) situated between Bhubaneswar/Odisha and Visakhapatnam in the Andhra regions. Simultaneously, another UACC is present near Myanmar in the Bay of Bengal.
Crucially, these two circulations are expected to merge in the coming hours and re-strengthen into a low-pressure area.
We anticipate that this system will rapidly intensify into a Depression (ஆழ்ந்த தாழ்வு மண்டலமாக) by tonight or tomorrow morning. This deep depression is forecasted to cross the coast between Odisha and Visakhapatnam either tomorrow night or the day after, early morning. Following landfall, it will move inland through interior Andhra and Telangana, continuing its journey towards Maharashtra.
The formation of continuous cyclonic circulations in these regions is likely due to the presence of an Equatorial Rossby Wave (ஈக்வட்டரியல் ரோஸ் பீவியூம்) and the influence of the MJO (Madden-Julian Oscillation) over the West Pacific.
Rain Hotspots: Next 24 Hours
Due to these intensifying systems, the Southwest Monsoon is expected to strengthen, bringing widespread rain to several states:
1. Andhra Pradesh & Telangana (The Hotspot): Andhra Pradesh is today's hotspot. Central Andhra districts—including Guntur, Palnadu, Bapatla, NTR, Eluru, and Godavari—are expected to see heavy rain and, in some areas, very heavy rain. The eastern parts of Telangana are also preparing for heavy to very heavy rainfall, particularly in districts like Adilabad, Karimnagar, Warangal, and Khammam.
• Kerala: Heavy to very heavy rain is forecasted for Thrissur, Ernakulam, Kottayam, Alappuzha, and parts of Kollam. Moderate to heavy rain is widespread across the rest of the state, including Thiruvananthapuram, Idukki, Palakkad, and Wayanad.
• Karnataka: Widespread moderate to heavy rain is expected, particularly in the Kalyana Karnataka regions (Bidar, Raichur, Vijayapura). Areas around the Cauvery catchment (Shivamogga, Kodagu) and Bengaluru may also experience moderate to heavy rain today. The continuous rain in the Cauvery catchment areas is predicted to slightly increase water inflow to the Mettur dam.
What About Tamil Nadu?
If you're wondering about rain in Tamil Nadu (TN), rest assured, the situation is not entirely dry. Convective rain (வெப்பச்சலன மழை) will continue.
However, the widespread nature of the convective rain may slightly decrease over the next four to five days.
Key Rain Areas for TN Today: Due to wind penetration, moderate or heavy rain is possible in Nagercoil, Kanyakumari, and Tenkasi. Moderate rain can be expected in Western Tirunelveli (Manjolai), Valparai, Solaiyar, and Pollachi areas. Thunderstorms are likely in Southern districts like Madurai and Sivaganga.
Widespread moderate to heavy rain is also possible across many districts, including Nilgiris, Erode, Krishnagiri, Salem, Delta districts (Thanjavur, Nagapattinam, Karaikal), Cuddalore, and North districts like Pondicherry and Villupuram.
Outlook: In major cities and suburbs like Chennai, Tiruvallur, Kanchipuram, Vellore, Coimbatore, and Thoothukudi, there may be increased ground winds and mostly light rain or cloud cover expected during the evening/night.
The good news is that after the next four to five days, the widespread rainfall events witnessed over the last 10 days are expected to resume!
--------------------------------------------------------------------------------
Disclaimer: This information is based on the personal weather estimation of Venkatesh MS Rainman. Weather is subject to change. Please follow official weather forecasts and announcements from the Indian Meteorological Department and government authorities.
For real-time updates, check the links provided for our WhatsApp, Facebook, and Twitter channel
Posts
