CHENNAI: The northeast monsoon, a crucial rain-bearing system for Tamil Nadu and Puducherry, has ended on a subdued note this year, with the India Meteorological Department (IMD) confirming an overall rainfall deficit across the region.
According to official data, Tamil Nadu and Puducherry together received 42.8 cm of rainfall during the October-December period, falling short of the normal average of 44.2 cm -- a deficit of about 3 per cent.
This comes despite early seasonal forecasts predicting above-normal rainfall.
The IMD has not yet formally declared the end of the northeast monsoon, indicating that it may continue until the second week of January, though any rainfall beyond that period will not be counted as part of the seasonal total.
October witnessed a strong start, recording 23 cm of rainfall, which was 36 per cent above normal. However, rainfall activity weakened significantly thereafter.
November received only 15 cm against a normal of 17 cm, while December recorded a mere 4.5 cm so far, compared to the usual 9 cm.
The weather officials attributed the subdued performance mainly to the absence of favourable synoptic systems such as low-pressure areas and cyclonic circulations over the Bay of Bengal during November and December -- systems that typically play a key role in driving northeast monsoon rains.
After five consecutive years of above-normal northeast monsoon rainfall, this year marks a departure from the trend.
Several districts, including Chennai, Ariyalur, Chengalpattu, Coimbatore, Dharmapuri, Dindigul, Kancheepuram, Karur, Krishnagiri, Perambalur, Salem, Theni, Tiruppur and Tiruchirappalli, recorded rainfall below normal levels.
Puducherry also experienced a seasonal deficit. However, some districts reported surplus rainfall.
Virudhunagar, Vellore, Thoothukudi, Tiruvarur, Tirunelveli and Tenkasi received rainfall above the seasonal average.
Despite the shortfall, officials said water storage levels remain comfortable, thanks to adequate inflows during the southwest monsoon and the early phase of the northeast monsoon.
Reservoirs across the state currently hold sufficient water to meet near-term drinking and irrigation requirements, offering some relief even as the monsoon season draws to a close.