Weather Alert: Deep Depression Intensifies, Monsoon Retreat Begins, and Rains Return (October 2, 2025)
Welcome to today's detailed weather analysis! This is my personal weather forecast. For official weather forecasts and information, please follow the Indian Meteorological Department (IMD) and official government announcements.
Today, October 2, 2025, marks a period of significant meteorological transitions across the Indian subcontinent. We are tracking two major systems currently active and preparing for the final stages of the Southwest Monsoon.
Deep Depression Forms in the Bay of Bengal
The low-pressure area that was persisting over the Bay of Bengal has rapidly intensified, as predicted, into a Deep Depression (ஆழ்ந்த தாழ்வு மண்டலம்). It is currently moving towards Odisha.
It is expected that by this evening or tonight, this system will intensify further into an Intense Deep Depression (தீவிர ஆழ்ந்த தாழ்வு மண்டலம் or Deep Depression). The IMD is expected to make an official announcement regarding this soon.
Landfall and Impact: The system is anticipated to cross the coast between Gopalpur, Odisha, and Gopalpur in Odisha this evening or tonight. Along its path during landfall, ground winds are expected to reach speeds of approximately 40 to 45 km/h. Yesterday afternoon, wind speeds near the center of the system were around 35 knots, positioning it almost at the verge of developing into a cyclonic storm (சிறு புயலாக). Currently, the system's wind structure places it around 31 knots.
Dual Systems and Western Disturbance Influence
In addition to the Bay of Bengal system, another weather system that moved from the Gujarat region into the Arabian Sea has also developed from a well-marked low-pressure area (நன்கமைந்த தாழ் பகுதி) into a Deep Depression.
However, both of these systems are projected to lose their intensity rapidly:
- Arabian Sea System: The Arabian Sea Deep Depression, which is moving westwards, is expected to weaken and become completely inactive as it is pulled back towards the Gujarat region.
- Odisha System: The system moving towards Odisha, after proceeding slightly westwards through Chhattisgarh and adjacent areas of Jharkhand, will also be pulled towards the Himalayan regions by the prevailing wind flow and will subsequently lose its intensity.
This rapid dissipation is linked to the Western Disturbance (WD) (மேற்கத்திய கழக்கம்), which is currently moving towards the northern districts of India. This WD influence is expected to weaken both systems within the next three days.
Monsoon Transition and Retreat
Following the dissolution of these systems, the Western Disturbance will begin to weaken gradually. The next five to six days will see a period of sluggishness (தொய்வான நிலையில) for the Southwest Monsoon.
The key timelines for the transition are as follows:
- Southwest Monsoon Withdrawal: The final withdrawal (விலக) of the Southwest Monsoon is expected to begin rapidly next week.
- Easterly Winds Onset: Easterly winds (கிழக்கு திசை காற்று) are expected to start moving towards Tamil Nadu around the 11th and 12th of the month.
- Northeast Monsoon Precursors: Rain associated with these easterly winds is expected to begin affecting the coastal districts of Tamil Nadu around the 15th and 16th.
Thermal Convection Rain (வெப்பசலனமழை) Begins in Earnest
Today marks the full-fledged start of thermal convection rain (வெப்பசலனமடை) across Tamil Nadu. This period, transitioning between the Southwest and Northeast Monsoons, is considered a boon (வரப்பிரசாதம்) for the interior districts, where there are opportunities for heavy rainfall.
Tamil Nadu Rain Forecast (Today, October 2):
- Widespread Moderate to Heavy Rain: Expected across Northern districts, including Chennai, Thiruvallur, Kanchipuram, Chengalpattu, Ranipet, Thiruvannamalai, Villupuram, Pondicherry, Cuddalore, Kallakurichi, Thirupattur, Dharmapuri, Salem, Namakkal, Karur, Perambalur, and Ariyalur.
- Scattered Light to Moderate Rain: Cloudy skies with isolated light or moderate rain are possible in Vellore, Krishnagiri, Erode, Nilgiris, Coimbatore, Valparai, Tiruppur, Dindigul, Trichy, Mayiladuthurai, Nagapattinam, Karaikal, Thiruvarur, Thanjavur, Pudukkottai, Theni, Madurai, Sivaganga, Virudhunagar, Ramanathapuram, Thoothukudi, Tenkasi, Tirunelveli, and Kanyakumari.
Rainfall Distribution: While scattered rains occurred yesterday in some Northern districts, today they will be widespread across Northern and Western districts. From tomorrow onwards, this rain is expected to extend to the Southern districts as well.
Other State Rain Forecasts (Next 24 Hours)
Kerala: Moderate to heavy rain is likely in Kasargod, Kannur, Kozhikode, and Wayanad. Moderate to heavy rain is also expected in Idukki, Pathanamthitta, Kollam, and the regions bordering the Western Ghats in Thiruvananthapuram. Light rain is expected in coastal areas of other districts like Malappuram, Palakkad, Thrissur, Ernakulam, Kottayam, and Alappuzha.
Karnataka: Moderate to heavy rain is forecast for Coastal Karnataka (Uttara Kannada, Udupi, Dakshina Kannada), Kodagu, Tumkur, Chikmagalur, Davanagere, Shimoga, Dharwad, and Belgaum districts. Other districts, including Bangalore, are likely to experience light rain.
Andhra Pradesh: Moderate to heavy rain is predicted for Chittoor, Tirupati, Nellore, Kakinada, Godavari, and Alluri Sitharama Raju districts. Heavy rain is possible in Anakapalle, Vizianagaram, Visakhapatnam, and Srikakulam. Rayalaseema districts, including Kurnool, Nandyal, and Kadapa, may see cloudy skies with isolated light rain.
Telangana: Moderate to heavy rain is expected in the western, northwestern, and southwestern parts of the state, including Jagtial, Komaram Bheem, Mancherial, Peddapalli, Jayashankar Bhupalpally, and Kothagudem. Other districts, including Hyderabad, are likely to experience light rain in isolated areas.
Remember to follow the daily weather reports to stay informed about where rain is occurring. Please note that weather conditions are subject to change.
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