The India Meteorological Department (IMD) has revised its rainfall forecast for Chennai and its neighbouring districts, following the development of a deep depression over the Bay of Bengal. The weather system is now expected to cross the Sri Lanka coast on Friday, significantly reducing the likelihood of heavy downpours in the capital city of Tamil Nadu.
Revised Alerts and District-wise Impact
On Thursday, the IMD officially withdrew the heavy rainfall warning that was in place for Chennai, Kancheepuram, and Tiruvallur districts for January 10. However, it maintained a yellow alert for Chengalpet, predicting heavy rainfall between 6 to 12 centimetres within a 24-hour period on the same day.
According to an IMD bulletin, Friday will bring one or two spells of light to moderate rain to some areas in and around Chennai. The skies are likely to remain partly cloudy, pegging the maximum temperature between 28–29°C and the minimum around 24°C.
Where Will the Heavy Rain Hit?
While Chennai gets a respite, the intense weather system is set to lash other parts of Tamil Nadu. The IMD has issued an orange alert for Tiruvarur and Nagapattinam districts, forecasting very heavy rainfall of 12–20 cm on January 9. Neighbouring districts are also under a heavy rainfall warning for that day.
The impact is expected to continue on January 10, with very heavy rainfall likely to extend to Cuddalore district. Chengalpet is also slated to receive heavy spells during this period.
Rainfall Data and Expert Analysis
So far in January, Chennai has recorded 21.8 mm of rainfall, which is a significant 156% above the normal average for this period. Data from key observatories shows a varied picture: Nungambakkam logged 30 mm (about 22.7 mm excess), while Meenambakkam recorded 8.5 mm (around 3.5 mm below normal).
Weather blogger Pradeep John provided additional insight, noting that only the high-resolution ECMWF model suggests the system could move further towards Tamil Nadu after crossing Sri Lanka. "The city will get rainfall between January 10 and 12. There is also a possibility of light rain spells on Friday night. Even if the rain intensity varies, cloudy weather will keep day temperatures down," John stated, indicating that Chennai is not completely out of the woods.
What This Means for Chennai
The shift in the depression's path brings a mixed bag for the region. Chennai residents can expect milder weather conditions with sporadic light rain, offering relief from potential flooding. However, authorities and citizens in the delta and adjoining districts must remain on high alert for the possibility of very heavy rainfall and its associated impacts over the next two days.
