Red and orange alerts issued for several districts for October 22 and 23

CHENNAI: The brief but intense spell of rain on Tuesday could have been the opening act of what seems to be a heavy monsoon season, with not one but two low-pressure systems, one over the southwest Bay of Bengal and the other in the southeast Arabian Sea, likely to develop into depressions on Wednesday.

The Regional Meteorological Centre (RMC), Chennai, has issued yellow, orange, and red alerts (heavy, very heavy, and extremely heavy rainfall) in several districts in the region, including Chennai and neighbouring districts, over the next couple of days.

The low-pressure area that has formed over the southwest Bay of Bengal is expected to intensify into a depression by October 22 afternoon. It is forecast to move west-northwestwards, affecting the northern coast of Tamil Nadu, and Puducherry, Karaikal, and South Andhra Pradesh. Further intensification is expected within the next 24 hours, officials said.

Meanwhile, a separate, well-defined low-pressure area is persisting over the southeast Arabian Sea. This system, too, is likely to develop into a depression, slowly moving westwards.

A red alert has been issued for Wednesday for Chengalpattu, Villupuram, Cuddalore, and Mayiladuthurai districts, as well as Puducherry, which are expected to receive extremely heavy rain is likely at one or two places, while orange and yellow alerts (heavy to very heavy rainfall) have been issued for several districts, including Chennai, Tiruvallur, Kancheepuram, Ranipet, Tiruvannamalai, Kallakurichi, Ariyalur, Perambalur, Thanjavur, Tiruvarur, and Nagapattinam, and Karaikal.

Also, Salem, Tiruchy, Vellore, Tirupattur, Dharmapuri, and Pudukkottai are likely to receive heavy rainfall.

The forecast says the situation is likely to remain the same on Thursday, with isolated places in Chennai, Chengalpattu, Tiruvallur, Kancheepuram, and Ranipet districts likely to receive heavy to very heavy rainfall.

Heavy rain is also expected in Vellore, Tirupattur, Tiruvannamalai, Villupuram, Kallakurichi, and Cuddalore districts, and Puducherry.

The initial period of the northeast monsoon has been a banger so far, with the region receiving 16 cm of rainfall, 6 cm above the normal, between October 1 and 21. Sixteen districts have already received normal or above-normal rainfall.

Until October 23, squally weather with wind speeds of 35-45 kmph, gusting to 55 kmph, is likely along the Tamil Nadu coast, the Gulf of Mannar, and adjoining areas. Noting that sea conditions will be rough, the weather forecast advised fishermen not to venture into these areas, and those already at sea were urged to return to the coast immediately.