Weather Update: Wind Convergence Brings Moderate to Heavy Rain to South Tamil Nadu Today (November 9)
Disclaimer: This forecast is a personal weather estimation for November 9, 2025. For official weather announcements and detailed warnings, please refer to the India Meteorological Department (IMD) and government announcements.
Current Weather Dynamics and Wind Shifts
We are currently observing the influence of Continental Air (also referred to as Continental Dragger) moving in from Central India. Simultaneously, North-West/North-East winds are also present. The combination of these systems is resulting in slightly higher daytime temperatures and reduced rainfall in North Tamil Nadu and Andhra regions.
A Trough system that originated near the Andaman regions has shifted slightly west. In the coming days, this trough is expected to move further west, approaching the Tamil Nadu coast. However, upon nearing our coast, the system might weaken and move further south. This movement is important because it will cause the impact of Easterly winds to recede. The winds are expected to shift to West/North-West directions (referred to as North-North East winds in the source), which will continue to provide rainfall opportunities for Coastal Tamil Nadu and South Tamil Nadu.
Today's Rain Focus: South Tamil Nadu
For today, the major rain focus remains on South Tamil Nadu. As the Continental Air moves closer, wind convergence (Katru Kuvithal) is occurring in the southern parts of Tamil Nadu. This is due to winds twisting from various directions in that region.
This specific setup—where the moist convergence occurs below a layer of dry air that flows over Central Tamil Nadu—creates friction. This friction is expected to lead to the formation of heavy rain clouds. Consequently, we expect widespread moderate to heavy rainfall in South Tamil Nadu today, similar to yesterday.
Districts where this moderate to heavy rain is anticipated include: Theni, Madurai, Sivaganga, Virudhunagar, Ramanathapuram, Tenkasi, Thoothukudi, Tirunelveli, and Kanyakumari.
Rainfall Recorded in the Last 24 Hours
In the 24 hours prior to this forecast, several areas recorded significant rainfall:
Tamil Nadu Highlights: Good rain was registered in Madurai past midnight.
- Thiruparankundram (Madurai): 56.8 mm
- Erichanathal (Virudhunagar): 42 mm
- Thirumangalam (Madurai): 39.2 mm
- Sivarakoorai (Madurai): 38 mm
- Vijayanarayanapuram (Tirunelveli): 31.2 mm
- Kariwala Vattanallur (Tenkasi): 28.4 mm
Kerala Highlights: Most parts of South Kerala saw good rainfall.
- Ponmudi West (Thiruvananthapuram): 39 mm
- Vellathooval (Idukki): 31 mm
- Mattancherry (Ernakulam): 30.5 mm
- Mukka Munakkal (Thrissur): 33.5 mm
Next 24 Hour Regional Forecast
Kerala:
- Moderate to heavy intermittent rain is expected in seven districts, including Thiruvananthapuram, Kollam, Pathanamthitta, Idukki, Kottayam, Alappuzha, and Ernakulam.
- Light rain is possible in Thrissur, Palakkad, Malappuram, and Wayanad districts.
- Kozhikode, Kannur, and Kasargod are likely to see dry weather.
Tamil Nadu (Other Regions):
- Nilgiris and Coimbatore: Widespread light to moderate rain is possible.
- Coastal and Central Districts (including Chennai, Tiruvallur, Kanchipuram, Villupuram, Pondicherry, Cuddalore, Nagai, Thanjavur, and Dindigul): Expect higher daytime temperatures. Light to moderate rain is possible in these areas, primarily during the evening, night, or early morning hours.
Andhra Pradesh:
- Light to moderate rain is possible in Nellore, Kavali, and parts of the Tirupati area. Dry weather is expected elsewhere.
- Karnataka & Telangana:
- These regions are largely expected to experience dry weather. Temperatures will be warmer than usual, with daytime temperatures potentially 2 degrees higher and nighttime temperatures 1 degree higher than normal.
Long-Term Weather Drivers: The MJO and Kelvin Wave
Looking at the broader picture, weather models currently do not show a consensus regarding any major disturbance . Analysis of the Madden-Julian Oscillation (MJO) suggests a weak progression that may fade after the Phase of 6 or 7.
However, the Kelvin Wave is currently situated over the Indonesian regions, leading to dense cloud formation there. The source suggests that the Kelvin Wave often precedes the MJO, stating: "The bell rings before the elephant arrives".
With the Kelvin Wave in place and the Indian Ocean Dipole (IOD) beginning to weaken, the MJO is expected to appear in the next four to five days. This activity will subsequently bring the Equatorial Rossby Wave (R-wave). The resulting friction between the MJO and R-wave is anticipated to bring disturbances to the Bay of Bengal. Although current models indicate the MJO will likely be low in intensity(How ever Realtime Intensity may be in different), this overall increase in activity is expected to boost rainfall opportunities in Tamil Nadu in the coming days.
#Thunderstorms #Rains #Keralarains #Karntakarains #TNRains #ChennaiRains #KTCC #Masrainman #Kerala #Karnataka #Bengaluru #HyderabadRains #Telangana #Andhrapradesh #Chennai #NEM2025
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