The cyclonic storm 'Amphan', which is currently moving over Southeast Bay of Bengal, is likely to turn into a very severe storm and make a landfall on West Bengal coast on May 20, the home ministry said on Sunday.

The cyclonic storm 'Amphan' (pronounced as UM-PUN) is moving over Southeast Bay of Bengal and neighbourhood and has been turning north-northwestwards with a speed of 6 kmph over past six hours, it said.

It has intensified slightly and lay centred over the same region at 0530 hrs IST on Sunday, a home ministry official said, quoting an India Meteorological Department bulletin.

The storm is currently spotted near latitude 11.4 N and longitude 86.0 E, about 990 km south of Paradip (Odisha), 1,140 km South-Southwest of Digha (West Bengal) and 1,260 km South-Southwest of Khepupara (Bangladesh).

It is very likely to intensify further into a severe cyclonic storm during next six hours and turn into a very severe cyclonic storm during subsequent 12 hours, the ministry official said.

It is very likely to move nearly northwards by Monday and then re-curve north-northeastwards across Northwest Bay of Bengal and cross West Bengal-Bangladesh coasts between Sagar Islands (West Bengal) and Hatiya Islands (Bangladesh) during the afternoon or evening of May 20 as a very severe cyclonic storm, the official said.

The National Crisis Management Committee (NCMC) on Saturday reviewed the preparedness for the impending cyclone and directed immediate assistance to West Bengal and Odisha.

A meeting of the NCMC, headed by Cabinet Secretary Rajiv Gauba, was held to take stock of the preparations for the cyclone.

The cabinet secretary reviewed the current situation and preparedness for rescue and relief operations and directed that immediate assistance, as required, be provided, an official statement had said.

Heavy to extremely heavy rainfall, accompanied by high speed winds and tidal waves are expected in the region.