Northeast Monsoon Begins: Heavy Rain Forecast Across Tamil Nadu Till October 22
The much-awaited northeast monsoon has officially begun in Tamil Nadu, bringing widespread rainfall across several districts. The India Meteorological Department (IMD) has forecast rain at various places across the state till October 22, marking an active start to the season.
According to IMD, a low-pressure area is likely to form over the southeast Bay of Bengal on October 24, which may intensify and bring more rain to coastal and southern regions in the coming days.
Importance of the Northeast Monsoon
The northeast monsoon plays a crucial role in Tamil Nadu’s climate, contributing 48% of the state’s annual rainfall and nearly 63% of Chennai’s annual rainfall.
Average Rainfall (Season): Tamil Nadu – 45 cm | Chennai – 87 cm
Heavy to Very Heavy Rainfall Alert
IMD has issued an orange alert for five southern districts, warning of heavy to very heavy rainfall (12–20 cm) in the next 24 hours. In addition, 14 districts in coastal, western, and central regions are under a yellow alert, where heavy rain (6–12 cm) is expected.
- October 18–20: Heavy rain likely to move towards western districts.
- October 21–22: Heavy rain may return to coastal areas.
Chennai Weather Forecast
For Chennai, light to moderate rain with thundershowers is expected today.
- Sky: Partly cloudy
- Temperature: Maximum – 32°C, Minimum – 25–26°C
Weather Systems Over Seas
- Southeast Arabian Sea: A low-pressure area is likely to form on October 18 off the Kerala–Karnataka coast, but it is expected to move away from the Indian shoreline.
- Southeast Bay of Bengal: Another system is expected to develop by October 24, which may strengthen and move west-northwest, potentially enhancing rainfall activity.
Cyclone Possibility
According to the Chennai Meteorological Department, storms are common between October and December, but it is too early to predict the number or timing of any potential cyclones this year.
IMD sources have indicated that Cyclone Fangel may strengthen in the Bay of Bengal, influencing weather conditions over the next few days.
Expert Insights
Mahesh Palawat, Chief Meteorologist at Skymet Weather, noted that the northeasterly winds required for the onset of the monsoon have arrived even before the complete withdrawal of the southwest monsoon.
He added, “When there is no depression in the north or central Bay of Bengal, the winds turn towards Tamil Nadu, leading to the onset of the northeast monsoon. The state is expected to receive widespread rainfall for the next one week.”
Rainfall Data (as of October 17)
- Chennai: 8 cm rainfall – 7% below normal
- Tamil Nadu: 10 cm rainfall – 38% above normal
Stay updated on weather alerts and travel advisories from IMD to plan your Diwali week safely and comfortably.
