Kolkata, May 19 : At least 12 National Disaster Response Force (NDRF) teams have been kept on stand-by as the cyclonic storm is likely to hit a large part of the coastal areas with "very heavy rainfall" on Wednesday evening. Besides West Bengal, a warning has also been issued for Odisha, Sikkim and Meghalaya till Thursday. Cyclone Amphan (pronounced as 'um-pun') is expected to make a landfall somewhere between West Bengal's Digha and Hatya Island in Bangladesh. A part of it may also make a landfall somewhere between Kakdwip and Sagar Island in the state's South 24-Parganas district at a minimum speed of 155-165 km/hour (maximum 185 km/hour). Currently, the cyclonic storm lies centred over west-central Bay of Bengal about 570 km nearly south of Paradip in Odisha, 720-km south-west of Digha (West Bengal) and 840-km south-southwest of Khepupara in Bangladesh. Union home minister Amit Shah on Tuesday called up West Bengal Chief Minister Mamata Banerjee assuring her necessary assistance from the Centre. Sources at the state secretariat Nabanno said that Shah telephoned West Bengal CM this morning and spoke to her in detail about the arrangements made in various south Bengal districts. He reportedly told the CM that the Centre is keeping a close watch on all the developments related to the cyclonic storm. "The Union minister also said the Centre is ready to provide, if needed, all relief materials to the state government," state government sources said. Earlier, Banerjee had already directed the state disaster management authorities to transport the evacuees to temporary cyclone centres for safety. Three coastal districts of East Midnapore, South 24-Parganas and North 24-Parganas are expected to be the worst affected in the cyclonic spell. Besides these three districts, cyclone Amphan is also likely to affect other south Bengal districts -- Howrah, Hooghly, West Midnapore and Kolkata. Round-the-clock control rooms have been opened in several districts to review the situation. Several steps have been taken by the Kolkata Municipal Corporation (KMC) and the Kolkata Police to monitor the situation on an hourly basis. A centralised control room has also been opened at the KMC, Arannya Bhavan and the state secretariat Nabanno to keep a close watch on the situation. /IANS