Chennai: Sunshine and cloudy skies interspersed throughout the day, followed by light rain in parts of the city on Thursday night. From Friday, heavy monsoon rain is likely to return to the city, with the IMD issuing a yellow alert for heavy rainfall of 6- 12cm in 24 hours in the city and neighbouring districts over the next four days.The rainfall is associated with a low-pressure area that formed over the southwest Bay of Bengal and has since moved to the Comorin region and adjoining parts of southern Tamil Nadu and Kerala. Its associated cyclonic circulation extends up to 5.8km above mean sea level, helping lift moist air, which cools and condenses to form rain-bearing clouds. The system and atmospheric instability are expected to sustain rainfall over several parts of the state.The system may move northwards, bringing rain to Chennai and surrounding areas, an IMD official said. The city may receive moderate to heavy rain with thunderstorms and lightning on Friday. Cloudy skies are likely to keep maximum temperatures at 31-32°C and minimum temperatures at 25-26°C, according to the IMD.The agency has forecast heavy rain in 26 districts on Friday, including Chennai and Tiruvallur. From Oct 24 to 26, the warning will also cover Chengelpet and Kancheepuram, along with several delta and interior districts.An orange alert for heavy to very heavy rain has been issued for districts along the Western Ghats from Oct 23 to 26.
