Chennai, Nov 23 : The Regional Meteorological Centre (RMC) has issued a yellow alert for North Tamil Nadu, including the state capital Chennai, on November 27 and 28.

According to the weather department, the rainfall will be caused by a low-pressure system over the southeast Bay of Bengal.

This weather system is expected to develop on Saturday and intensify into a depression over the next two days, bringing heavy rainfall, said the MeT officials.

The RMC clarified that this system is not expected to develop into a cyclonic storm. The department's statement noted that rains are returning to North Tamil Nadu after a brief dry spell.

The forecast predicts 6 to 12 cm of rainfall within 24 hours on November 27 and 28. Heavy rainfall is expected in Kancheepuram and Chengalpattu on November 26, followed by widespread heavy rain across North Tamil Nadu on November 27 and 28. Cuddalore and Ramanathapuram districts will also experience heavy rain on November 27, prompting a yellow alert for these regions.

The RMC has issued an orange alert for November 26 in six Tamil Nadu districts and Karaikal region, and a yellow alert for four districts and Puducherry. Villupuram and Mayiladuthurai districts are on orange alert for November 26, while 10 districts, including Tiruvallur to Nagapattinam, are on yellow alert for heavy spells.

Since the onset of the northeast monsoon, Chennai has recorded 55 cm of rainfall, reflecting a slight deficit of 2 per cent, while Tamil Nadu as a whole has received 33 cm of rainfall, exceeding the average by 5 per cent.

Weather officials stated that the expected heavy rain in Chennai on November 27 and 28 is likely to eliminate the rain deficit and bring normal to excess rainfall to the city.

However, heavy rains in the Delta districts of Tamil Nadu, often referred to as the 'rice bowl' of the state, are causing concern among Samba paddy farmers.

The districts of Mayiladuthurai, Thanjavur, Tiruvarur, and Nagapattinam have been experiencing significant rainfall, leading to severe inundation and water stagnation. In Sembanarkoil, Mayiladuthurai recorded 68 mm of rainfall over the past two days.

In Tiruvarur district, Nannilam recorded 59 mm, and Needamangalam received 47.7 mm. The heavy rainfall and waterlogging are likely to cause extensive damage to the Samba crops in these districts, where paddy cultivation spans large areas.

As of now, Tamil Nadu has been receiving consistent rainfall since the monsoon began on October 17. Nearly 90 reservoirs across the state are over 60 per cent full.

The reservoirs currently hold 143.804 tmcft (thousand million cubic feet) of water, which is 64.11 per cent of their total capacity of 224.297 tmcft. This marks a significant improvement compared to the same period last year when storage levels were at 79.514 tmcft (35.58 per cent).

The Mettur reservoir, a critical water source, has a storage level of 62,140 tmcft -- a 384 per cent increase compared to 2023. Similarly, the Bhavanisagar reservoir recorded 21,141 tmcft, reflecting a 210 per cent rise from last year.

/IANS