A low-pressure area was developed over the Bay of Bengal to the southeast of Sri Lanka by Thursday, which is expected to move northwest towards Tamil Nadu coast and intensify into a cyclonic storm by April 29, according to the Indian Meteorological Department (IMD).
However, the IMD has warned that this could result in very rough/high sea condition over the South Bay of Bengal and squally/gale force winds (70-80 kmph) along and off Tamil Nadu coast, southwest Bay of Bengal and Comorin area.
Due to this cyclonic activity, Chennai MET department said moderate to heavy rain likely to occur over coastal Tamil Nadu and Puducherry April 29 onwards, reported news agency ANI.

Around 64 per cent of the flights that were diverted from four metro cities -- Mumbai, Delhi, Bengaluru and Chennai --- last year were due to bad weather conditions, an official document stated.
According to estimates of the Ministry of Civil Aviation, in 2018, the worst affected airport due to "bad weather" conditions was Delhi airport as 213 flights were diverted because of it.
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The weatherman Thursday forecast dust storm or Thunderstorm in the city where the minimum temperature settled at 28 degrees Celsius, five notches above season's average. The maximum temperature later in the day is likely to be 42 degrees Celsius.
Heavy to very heavy rain is expected in the Southern state of Tamil Nadu and Puducherry, IMD said. The IMD had already issued a cyclone warning in the state. The cyclone is expected to hit by April 29.
Amid soaring temperatures, Prime Minister Narendra Modi will campaign in Varanasi, whereas Congress chief Rahul Gandhi will campaign in Rajasthan. PM Modi will carry out roadshow. Click here for LIVE updates
AccuWeather's report said that the temperatures in Delhi are only expected to rise in this week or by early next week, surpassing yesterday's 43 degrees Celsius. The report said the temperatures will rise beyond 43 degrees, adding that the hottest locations might see 48 degrees Celsius by Sunday or Monday.
The India Meteorological Department (IMD) has warned of thunderstorm along with gusty winds at isolated places in Kerala, South Karnataka, West Bengal, Assam, Tripura, Manipur, Mizoram, Nagaland, Sikkim, and Meghalaya. It has also predicted heavy rainfall in Assam, Meghalaya, Arunachal Pradesh, West Bengal and Sikkim.
A low-pressure area developed over Bay of Bengal is expected to move northwest towards Tamil Nadu and intensify into a cyclonic storm by April 29, IMD said. It has warned of very rough/high sea conditions. The IMD has also predicted that isolated places in Tamil Nadu and Puducherry might witness heavy to very heavy rainfall.
Delhiites woke up to a sunny morning on Thursday with the temperature at 34 degrees Celsius. With partly cloudy skies, the maximum temperature might settle at 42 degrees Celsius, while the minimum temperature might settle at 27 degrees Celsius, reported AccuWeather.
IMD predicts strong winds with a speed of 30-40 km per hour, likely over the Indian Ocean and Bay of Bengal. IMD also issued a warning of strong, gusty winds over the Andaman Sea. The weather department has advised fishermen to stay away from these areas.
The IMD predicted that Delhi might witness strong winds with cloudy skies in the evening. The national capital recorded the hottest day of the season on Wednesday with the maximum temperature at 43 degrees Celsius and the minimum temperature settling in at 27.1 degrees Celsius.
The strong winds and rain, which hit Punjab on Wednesday afternoon, may delay the harvesting further as this weather is predicted on Thursday as well by the Meteorological department. Till April 23 only 16.42 LMT wheat arrived in grain markets. Read more
Pune, on Wednesday, witnessed the hottest day in the month of April since 2013. The mercury soared to 41.1 degrees Celsius. The Met Office has warned that over the next two days, maximum temperatures over the city are likely to rise further. The minimum temperature in the city settled at 25 degrees Celsius. Read more
Chandigarh was treated with strong winds and cooling showers on Wednesday evening. The Met department recorded a wind speed of 55.5 km per hour at around 7 pm. A tree in Sector 36-C got uprooted due to the wind, damaging the boundary wall of a house. Read more