CHENNAI: The deep depression that intensified into Cyclone Murasu is likely to gain strength in the coming hours, bringing heavy to very heavy rains to northern parts of Tamil Nadu on Monday and Tuesday, as it moves towards neighbouring Andhra Pradesh, said weather experts on Sunday.
After the Regional Meteorological Centre, Chennai, issued an orange alert for Chennai and Tiruvallur districts, the Tamil Nadu Disaster Risk Reduction Agency directed district collectors of several districts to remain on high alert.
According to the RMC, the cyclone is very likely to continue moving west-northwestwards and intensify into a severe cyclonic storm by Monday morning. It is then expected to recurve and cross the south Andhra Pradesh coast between Nellore and Narsapur as a severe cyclonic storm between 11.30 pm on Monday and 4 am on Tuesday (November 3). The storm is expected to bring sustained wind speeds of 100 to 110 kmph, with gusts reaching 120 kmph. Under its influence, Chennai and Tiruvallur are likely to experience thunderstorms, lightning, and gusty winds.
On November 2, heavy to very heavy rainfall is forecast at isolated places in Chennai and Tiruvallur, while heavy rainfall is likely in Chengalpattu, Kancheepuram, Ranipet, Vellore and the Nilgiris.
In meteorological parlance, heavy rainfall (yellow alert) implies 70-110 mm rainfall, while very heavy rainfall (orange alert) means up to 200 mm rainfall in 24 hours.
The intensity is expected to decrease on November 3, with heavy rainfall confined to isolated places in the Nilgiris. On November 3, isolated heavy rainfall accompanied by thunderstorms is likely over the Nilgiris.
Additional Chief Secretary and Commissioner of Revenue Administration and Disaster Management B Chandramohan directed collectors of these districts to immediately mobilise the administrative machinery and implement precautionary measures. Emergency response teams and district authorities have been instructed to maintain strict vigilance and promptly report any untoward incidents to the State Emergency Operations Centre (SEOC) to facilitate swift rescue and relief operations.
Fishermen have been advised not to venture into the sea until November 4 morning. Those fishing in deep waters have been asked to return immediately to the harbour or coast.
Residents have been advised to avoid beaches and coastal roads, waterlogged underpasses and fallen power lines, and follow weather updates.
Explaining the impact of the cyclone on moisture conditions, easterly winds, and rainfall activity, weather blogger Pradeep John, popularly known as Tamil Nadu Weatherman, told DT Next: "Cyclone Arnab had cut off the easterly winds, resulting in dry weather in northern Tamil Nadu and other parts of the State.
However, Cyclone Murasu has not disrupted the easterly winds. As the severe cyclonic storm is expected to make landfall near Nellore, rainfall activity is likely to continue across the State over the next few days."