The cyclonic storm 'Nisha' over South West Bay of Bengal remained practically stationary and lay centred near Nagapattinam coast in the early hours of the day, weather office said. The system was likely to move in the North Westerly direction and cross Tamil Nadu coast near Nagapattinam this afternoon. Under its influence, rainfall at most places with heavy to very heavy rains with gusty winds were likely to occur for the next 24 hours. Most parts of the state were reeling under the grip of heavy rains. Chennai city experienced adamant rains throughout last night and weather office forecast is no let up for the next 24 hours. Since the onset of monsoon in October, the rains have so far claimed 64 lives, including 40 in the last couple of days, official sources said.