However, the cyclone is expected to skip Chennai and move towards Bangladesh-Myanmar coast in the next couple of days.
The storm lay centred at 5.30 am at about 700 km southeast of Chennai. "It will move initially north-northwestwards during next 12 hours and thereafter northeastwards towards Bangladesh-Myanmar coast," a Met office bulletin said.
Under its influence rainfall at many places with isolated heavy rainfall would occur over Andaman and Nicobar Islands during next 48 hours.
Squally winds speed reaching 40-45 km per hour gusting to 60 km per hour would prevail along Andaman and Nicobar Islands during the period and sea condition would be rough to very rough.
Fishermen of Andaman and Nicobar Islands are advised not to venture into the sea during next 48 hours.
The Met office has also forecast rain or thundershowers at a few places over Tamil Nadu, Puducherry, coastal Andhra Pradesh and south interior Karnataka.
Heavy rains accompanied by thunder and lightning lashed several parts of the city, especially the suburbs in the early hours, bringing respite from the sweltering heat.
A Chandigarh-bound Jet Airways flight was cancelled this morning owing to intermittent weather, airport officials said.
The Met office said sky conditions would be generally cloudy over the city and rain or thundershower would occur in some areas during the day.