The US Joint Typhoon Warning Centre has located cyclone 'Roanu' to 320 km west-southwest of Chittagong in Bangladesh this morning.

The US agency saw the cyclone entering a 'marginally favourable environment' with warm sea waters and weak to moderate vertical wind shear.

Warmth of the sea waters will allow the cyclone to make gains from enhanced convection (process of cloud-building) while lesser wind shear effect at the top will help keep the 'storm tower' in tact.

Given these factors, the US agency assessed that there is scope for slight intensification of the cyclone before it makes landfall over the Bangladesh coast near Chittagong.

India Met Department said 'Roanu would skirt the Odisha and West Bengal coasts and hit the South Bangladesh coast between Khepupara and Cox's Bazar close to Chittagong by this evening.

Interestingly, India Met had in its bulletin issued last night withdrawn its forecast for intensification of 'Roanu' into a severe cyclone, which is being contested by the US agency.

It was the US agency that had initially stated that the system would weaken a round before it makes a landfall, a position which it has since corrected.

India Met has forecast heavy to very rain at isolated places along the Odisha and Gangetic West Bengal coasts today associated with the passage of the cyclone.

Heavy rain has also been forecast for the North-Eastern states of Assam, Meghalaya, Nagaland, Manipur, Mizoram and Tripura and squally winds for South Assam, Manipur and Tripura.